REVIEW OF THE SCOPE OF OPTOMETRIC PRACTICE IN NIGERIA

Optometry as a profession has a very important place in primary health care delivery.
Primary is defined as essential health care based on practical, scientific and socially
acceptable methods and technology made universally accessible to individuals and
families in the community by means acceptable to them, through their full
participation and at a cost that the community and country can afford to maintain at
every stage of their development in a spirit of self-determination. It forms an integral
part of the country health system of which it is the central function and main focus of
overall social and economic development of the community. It is the first level of
contact of the individual, the family and the community with the national health
system, bringing health care as close as possible to where people live and work.

Any profession must come under a professional body and such bodies must have a set
of rules and regulations to maintain its ethical standards in providing services to the
public. In Nigeria, Optometry had been regulated by a statutory body known as the
Optometrist and Dispensing Opticians Registration Board of Nigeria (ODORBN)
which was establishes by an Act of Parliament, Cap 09 of the Laws of the Federation
of Nigeria 2004, formerly known as Decree No. 34 of December 1989).

An Optometrist as defined by the Optometrist and Dispensing Opticians Registration

Board of Nigeria is a health-care professional specializing in the art and science of
vision care whose scope of practice include; eye examinations to determine refractive
errors and other departures from the optimally healthy and visually efficient eye and
correction of such errors as well as diagnosis and management of minor ocular
infections which do not pose a threat to the integrity of the visual system and ocular
first aid. The Optometrist is usually the first contact practitioner in the field of vision
and eye care. People consult them first most times about their vision and eye
problems. The Optometrist examines them, diagnose them and treat those cases
within his scope of practice while referring those cases outside his practice to either
the Ophthalmologist or other health practitioners as the case may be.
RELATION OF THE SCOPE OF PRACTICE OF THE EYE CARE TEAM

The eye care team consisting of the Optometrist, Ophthalmologist, Ophthalmic nurse and
Dispensing opticians works in an independent manner, with each member strategically
assigned specific roles.

The Optometrist is the first point of contact for individuals seeking eye care. The duties of an
Optometrist includes;

 Making a general observation of the patients and obtaining case histories.

 Formulating and implementing an examination plan.
 Assessing the ocular adnexa.
 Assessing the central and peripheral sensory visual function and the integrity of the
visual pathways.
 Assessing the refractive status of the eye as well as the oculomotor and binocular
functions.
 Assessing the significant signs and symptoms found incidental to ocular examinations
in relation to the patient’s eye or general health.
 To interpret and analyse findings to establish diagnoses.
 To design management plans for individual patients and implements the plans agreed
with the patient.
 To prescribe glasses and contact lenses and manage patients requiring vision therapy.
 To treat ocular disorders and injuries using appropriate pharmacological treatment
regimens within the permissible scope or refers patients appropriately.
 To identify patients that require surgical management and refers them appropriately.
 Conduct pre and post-surgical examinations and observations in collaboration with a
surgeon.
 Provide advice on vision and eye health and provides care to patients with special
needs
 Prescribes low vision devices and non-optical interventions to patients with low
vision.
 The Ophthalmologist

An Ophthalmologist is a medical practitioner who has had specialized post- graduate

training in Ophthalmology. They are expected to diagnose, treat (medically and
surgically) and prevent eye diseases, ailments and injury using specialized procedures
and techniques, applying principles of modern medicine to deliver comprehensive eye
care. They may also diagnose general diseases of the body and treat ocular
manifestations of systemic diseases. Duties of an opthalmologists includes;

 Obtaining patient history accurately and conducting a comprehensive patient

evaluation.
 Making clinical diagnosis based on the information gathered from the patient.
 Planning management (surgical or medical) together with patient and other health
professionals with the available information.
 Identifies and manages ophthalmic emergencies and trauma.
 Refers patients appropriately.
 Performs safe and high quality-surgery.
 Counsel patients and families on aspects of their eye health.

Ophthalmic Nurse
An ophthalmic nurse plays an important role in global eye health promotion, disease
prevention, diagnosis and treatment as well as low vision training and rehabilitation
services. Responsibilities of the ophthalmic nurse include;

 Measuring visual acuity, intraocular pressure and vital signs.

 Performing special clinical investigations such as ultrasound, fundus photography,
biometry and OCT scan.
 Administration of prescribed medication.
 Patient counselling.
 Assisting the ophthalmologist as necessary.
 Dispensing Optician

The dispensing optician is responsible for fitting patients with eye glasses and other
optical aids following a written prescriptions by the optometrists or (ophthalmologist).
They may also offer advice to patients on the different types of lenses and spectacles that
will suit the patient best based on their needs and occupation. They also counsel patients
on how to wear the glasses properly and also how to care for their spectacles. With
further training the dispensing opticians may also be able to fit the patient with contact
lens and also offer advice on contact lens care and use.

Anaesthesia in Eye surgeries

Local Anaesthesia
• Retro bulbar
• Peribulbar
• Subtenon's
• Subconjunctival
• Intracameral
• Topical

Advantages
• Can be administered by eye care personnel
• Relatively easy and requires less monitoring
• Favourable in cases where certain ocular parameters need to be monitored intra-op e.g.
eyelid position in ptosis surgery, medial rectus damage in pterygium excision

Disadvantages
• Uncooperative patient can affect surgical outcome
• Risk of damage to optic nerve, globe perforation, brainstem anaesthesia.
General Anaesthesia
• Advantages

• Ideal for children and uncooperative patients

• Outcome not affected by patient co-operation

• Disadvantages
• Require additional personnel (anaesthetist), skill and equipment

CATARACT SURGERY
• Cataract = opacity of the crystalline lens

TYPES OF CATARACT SURGERY

Intracapsular Cataract Extraction (ICCE)

The Intracapsular cataract extraction surgery involves the removal of the entire lens including
the intact capsule i.e. the posterior capsule which is removed by rupturing the zonules. The
most common indication for this type of cataract extraction surgery is markedly subluxated
and dislocated lens. Therefore weak and degenerated zonules are a pre-requisite for this
method. However this technique is becoming obsolete and almost no longer used worldwide.
Advantages of ICCE over ECCE
 The technique of ICCE, as compared to ECCE, is simple, cheap, easy and does not
need sophisticated micro instruments.
 Postoperative opacification of posterior capsule is seen in a significant number of
cases after ECCE. No such problem is known with ICCE.
 ICCE is less time consuming and hence more useful than ECCE for mass scale
operations in eye camps.
Surgical steps of intracapsular cataract extraction with anterior chamber intraocular lens
implantation: A, passing of superior rectus suture; B, fornix based conjunctival flap; C,
partial thickness groove; D, completion of corneo-scleral section; E, peripheral iridectomy; F,
cryolens extraction; G&H, insertion of Kelman multiflex intraocular lens in anterior chamber;
I, corneo-scleral suturing.
Extracapsular Cataract Extraction (ECCE)
Extracapsular cataract surgery is a type of cataract extraction in which the lens of the eye is
removed while the elastic capsule covering it is left partially intact to allow the implantation
of an intraocular lens (IOL)

In this technique, major portion of anterior capsule with epithelium, nucleus and cortex are
removed; leaving behind intact posterior capsule. Extracapsular cataract extraction technique
is the surgery of choice for almost all types of adulthood as well as childhood cataracts unless
contraindicated. The surgical techniques of ECCE presently in use for cataract extraction
includes:

 Conventional extracapsular cataract extraction (ECCE). Here an incision

measuring 10mm-12mm is made on the sclera in which the lens contents are removed.

 Manual small incision cataract surgery (SICS ). In this technique the lens nucleus is
removed through a scleral incision which is smaller than a standard ECCE and
measures 5mm-6mm

 Phacoemulsification. In this method the lens nucleus is broken inside the capsule by
ultrasound energy and removed through limbal incision measuring 3mm-5mm.
Surgical steps of conventional extracapsular cataract extraction with posterior
chamber intraocular lens implantation: A, anterior capsulotomy can-opener's
technique; B, removal of anterior capsule; C, completion of corneo-scleral section; D,
removal of nucleus (pressure and counter-pressure method); E, aspiration of cortex; F,
insertion of inferior haptic of posterior chamber IOL; G, insertion of superior haptic
of PCIOL; H, dialing of the IOL; I, corneo-scleral suturing.
Surgical steps of phacoemulsification : A, Continuous curvilinear capsulorrhexis; B,
Hydrodissection; C, Hydrodelineation; D&E; Nucleus emulsification by divide and conquer
technique (four quadrant cracking); F, Aspiration of cortex.
GLAUCOMA SURGERY
Glaucoma is not a single disease process but a group of disorders characterized by a
progressive optic neuropathy resulting in a characteristic appearance of the optic disc and a
specific pattern of irreversible visual field defects that are associated frequently but not
invariably with raised intraocular pressure (IOP). Thus, IOP is the most common risk factor
but not the only risk factor for development of glaucoma. Consequently the term ‘ocular
hypertension’ is used for cases having constantly raised IOP without any associated
glaucomatous damage. Conversely, the term normal or low tension glaucoma (NTG/LTG) is
suggested for the typical cupping of the disc and/or visual field defects associated with a
normal or low IOP. Treatment for glaucoma includes medical, surgical and laser therapy.

GLAUCOMA SURGERIES

Trabeculectomy
A surgical procedure featuring a partial thickness scleral flap that creates a fistula between
anterior chamber and subconjunctival space for filtration of aqueous and creation of
conjunctival bleb in an effort to lower the IOP. Trabeculectomy lowers the IOP by allowing
aqueous outflow from the anterior chamber to the sub-Tenon space. The procedure is usually
performed when medical therapy has failed to achieve adequate control of IOP.

Technique of trabeculectomy: A, fornix-based conjunctival flap; B & C, partial thickness

scleral flap and excision of trabecular tissue; D, peripheral iridectomy and closure of scleral
flap; E, closure of conjunctival flap.
Trabeculotomy
This involves the opening of the Schlemm’s canal into the anterior chamber to allow the
drainage of the aqueous from the eye thus lowering the IOP. It is primarily used for the
treatment of pediatric glaucomas, especially in cases where the cornea is cloudy. This
procedure is preferred in children because it is less invasive and less likely to cause cataract.
This is useful when corneal clouding prevents visualization of the angle or in cases where
goniotomy has failed. In this procedure, canal of Schlemm is exposed at about 12 O’clock
position by a vertical scleral incision after making a conjunctival flap and partial thickness
scleral flap. The lower prong of Harm’s trabeculotome is passed along the Schlemm’s canal
on one side and the upper prong is used as a guide. Then the trabeculotome is rotated so as to
break the inner wall over one quarter of the canal. This is then repeated on the other side. The
main difficulty in this operation is localization of the Schlemm's canal.

Technique of trabeculotomy

Glaucoma Drainage Devices

Glaucoma drainage devices (GDDs) principle work by creating an alternate pathway for
aqueous outflow by channelling aqueous from the anterior chamber through a tube implant
towards the sub-conjunctival space where it is absorbed into the systemic circulation by
diffusion and the through scleral veins. Glaucoma drainage devices are mostly used for
patients with history of uncontrolled glaucoma who have failed previous glaucoma surgery.
The use of drainage devices is also indicated in infantile glaucoma, neovascular glaucoma,
traumatic glaucoma, glaucoma in aphakia, glaucoma following corneal transplant etc.
example of glaucoma drainage devices includes the Molteno non-valved implant, the Ahmed
valve and the Krupin valve.

Artificial drainage shunt operation using Molteno implant.

Goniotomy
A surgical procedure in which the doctor uses a lens called a gonio lens to see the structures
of the eye (anterior chamber). An opening is made in the trabecular meshwork where the
fluids leaves the eye. The new opening provides a way for the fluid to flow out of the eye.
Goniotomy is a surgery used in the case congenital glaucoma in children. In this procedure a
Barkan's goniotomy knife is passed through the limbus on the temporal side. Under
gonioscopic control the knife is passed across the anterior chamber to the nasal part of the
angle. An incision is made in the angle approximately midway between root of the iris and
Schwalbe's ring through approximately 75°. The knife is then withdrawn. Although the
procedure may have to be repeated, the eventual success rate is about 85 percent.
Technique of goniotomy: A, showing position of goniotomy knife in the angle under direct
visualization; B, showing procedure of sweeping the knife in the angle.

Laser trabeculoplasty
Laser trabeculoplasty uses a very focused beam of light to treat the drainage angle of the eye.
This surgery makes it easier for fluid to flow out of the eye in order to lower the IOP.

 Argon laser trabeculoplasty (ALT): Involves the application of discreet laser burns
to the trabecular meshwork. This enhances the aqueous outflow and lowers IOP. ALT
is performed in open-angle glaucomas, usually as an adjunct to medical therapy.

 Selective laser trabeculoplasty (SLT): A relatively new procedure which uses the a
532nm frequency-doubled Q-switched Nd:YAG laser which selectively targets
melanin pigment in the trabecular meshwork cells, leaving non-pigmented structures
unscathed. Targeting is easier than with ALT which lead to more consistent results
being achieved. It may be safer than the ALT as there is no thermal tissue damage and
it is thought that the treatment can be repeated safely.

Minimally Invasive Glaucoma Surgery (MIGS)

IOP lowering surgery following characteristics that distinguish it from traditional glaucoma
surgery. It is minimally traumatic because of the conjunctiva preserving approach which
results in a rapid recovery and high safety profile. It is frequently combined with cataract
extraction. This procedure is currently targeted at patients with mild to moderate glaucoma.
Example of this procedure is the trabecular meshwork stents (iStent) which is designed to
improve aqueous outflow through the natural physiological pathway by creating a bypass
through the trabecular meshwork to Schlemm’s canal.

The aim of all glaucoma surgeries is to create a pathway for effective aqueous drainage and
lowering of IOP and NOT restoration of vision
CORNEAL SURGERIES
Corneal Transplant (Keratoplasty)
Corneal transplant is a surgical procedure in which diseased host cornea is replaced by
healthy donor cornea. Broadly, corneal transplants can be either partial thickness (anterior or
posterior lamellar) or full thickness/penetrating keratoplasty (PKP).

Superficial or Posterior Lamellar Keratoplasty

This involves a partial thickness excision of the corneal epithelium and stroma so that the
endothelium and part of the deep stroma are left behind. Indications for this surgical
procedure includes;

 Opacification of the superficial one-third of the corneal stroma not caused by

potentially recurrent disease.
 Marginal corneal thinning or infiltration as in recurrent pterygium.
 Localized thinning.

Deep Anterior Lamellar Keratoplasty

This is a relatively new technique in which the all opaque corneal tissue is removed almost to
the level of the Descemet membrane. The theoretical advantage is the decreased risk of
rejection, because the endothelium which is a major target of rejection is not transplanted.
Indications for this procedure includes;

 Diseases involving the anterior 95% of corneal thickness with a normal endothelium
and absence of breaks in the Descemet membrane.
 Chronic inflammatory diseases such as atopic keratoconjunctivitis

Penetrating Keratoplasty (PKP)

Penetrating keratoplasty is the most commonly performed corneal transplantation procedure

performed in diseases that involves all the layers of the cornea.
Indications for Penetrating Keratoplasty (PKP)

 Optical keratoplasty is performed to improve vision. Important indications include

pseudophakic, bullous keratopathy, keratoconus, dystrophies, degenerations and
scarring.

 Tectonic grafting may be carried out to restore or preserve corneal integrity in eyes
with severe structural changes such as severe thinning with descemetocele.

 Therapeutic corneal transplantation may afford removal of infected corneal tissue in

eyes unresponsive to antimicrobial therapy.

 Cosmetic grafting may be performed to improve the appearance of the eye, but is a
rare indication.

. Optical
• Bullous keratopathy (pseudophakic and aphakic)
• Keratoconus
• Corneal dystrophy
• Corneal inflammatory diseases - interstitial keratitis
• Corneal traumatic scars
• Failed grafts

Tectonic
• Corneal perforation
• Peripheral corneal thinning

Therapeutic
• Infective keratitis
Technique of keratoplasty : A, excision of donor corneal button; B & C, excision of recipient
corneal button; D, suturing of donor button into recipient's bed; E, showing pattern of
continuous sutures in keratoplasty; F, Clinical photograph of a patient with interrupted
sutures in keratoplasty.

Photorefractive Keratectomy (PRK)

Photorefractive keratectomy is performed with the excimer laser, which can accurately ablate
corneal tissue to an exact depth with minimal disruption of surrounding tissue. Myopia is
treated by ablating the central anterior corneal surface so that it becomes flatter,
approximately 10µm of ablation will correct 1D of myopia. Hypermetropic is treated by
ablation of the periphery so that the center becomes steeper. PRK is able to correct myopia of
up to 6D and low hypermetropia.

Arcuate Keratotomy (AK)

The Arcuate keratotomy also known as the limbal relaxing incision involves making a paired
arcuate incisions on opposite sides of the cornea in the axis of the correcting ‘plus’ cylinder
(the steep meridian). The resultant flattening of the steep meridian coupled with a smaller
steepening of the flat meridian at 90º to the incisions reduces the astigmatism. The desired
result can be controlled by varying the length and depth of the incisions, and their distance
from the optical centre of the cornea.

Laser Epithelial Keratomileusis (LASEK)

Laser epithelial keratomileusis is an adaptation of PRK. In LASEK the epithelium is first
detached and peeled back, laser is applied and then the flap repositioned. It is associated with
less pain, less haze and more rapid visual recovery than PRK. LASEK works well with low
corrections and for patients who are unsuitable for LASIK such as those with very thin
corneas.
Functional vision is usually achieved within 4–7 days and the procedure has a low risk of
serious complications. The main disadvantage compared with LASIK is variable epithelial
healing with unpredictability of postoperative pain.

Laser in Situ Keratomileusis (LASIK)

Laser in situ keratomileusis is a very commonly-performed refractive procedure. It is more
versatile than PRK and LASEK and can correct hypermetropia of up to 4 D, astigmatism of
up to 5 D and myopia of up to 12 D depending on corneal thickness. To decrease the risk of
subsequent ectasia, a residual corneal base of at least 250μm thickness must remain after the
flap has been cut and tissue ablated. The amount of tissue removed and the total treatment is
therefore limited by the original corneal thickness. The thickness of the flap can be varied but
thinner flaps are more difficult to handle and more prone to wrinkling.

Phakic Posterior Chamber Implant

Implantable contact lens (ICL) is inserted behind the iris and in front of the lens and
supported in the ciliary sulcus. The lens is composed of material derived from collagen the
with a power of −3 D to −20.50 D. Visual results are promising but the procedure may be
associated with uveitis, pupillary-block glaucoma, endothelial cell loss, cataract formation
and retinal detachment.

Corneal collagen cross-linking

Corneal collagen cross-linking involves the use of riboflavin drops to photosensitize the eye
followed by exposure to ultraviolet-A light. This is a newer treatment which offers promise
of stabilization or reversal of ectasia by making the corneal tissues stronger. Corneal cross
linking is mainly indicated in Keratoconus patients, it helps in stopping the progression of
Keratoconus and may help the patient avoid a corneal transplant.

.
Laser-induced monovision

This procedure refers to the use of laser refractive surgery to induce ‘monovision’, in which
one eye is set for emmetropia and the other for low myopia, in order to facilitate both good
distance and near vision with the eyes used together.

Kamra Presbyopic Corneal Inlay

The Kamra Inlay is a relatively new technique which uses the simple pinhole technique to
improve near vision by focusing light as it enters the eye. It consist of a 3.8mm inlay covered
with 8400 microscopic holes. Unlike monovision LASIK, the Kamra provides depth of focus.
The Kamra inlay is normally placed in the non-dominant eye of patients between the ages of
45 and 60. It works best for patients who have between +1 and +2D of presbyopia and who
do not already require distance vision correction.

EYELIDS EXCISION AND BIOPSY

Biopsy: A medical test that involves the removal of tissue sample for examination in the lab
under a microscope to determine the presence or extent of a disease.

The two types of biopsy are (a) incisional, using a blade, in which only part of the lesion is
removed to allow histological diagnosis, and (b) excisional, in which the entire lesion is
removed and a histological diagnosis made; the latter may be:

Shave excision using a blade to remove shallow epithelial tumours, such as papillomas and
sseborrhoeic keratosis. Full-thickness skin excision for tumours that are not confined to the
epidermis. Surgical excision. Surgical excision aims to remove the entire tumour with
preservation of as much normal tissue as possible. Smaller tumours can be removed via an
excision biopsy and the defect closed directly, whilst awaiting histological confirmation of
complete clearance.

Standard frozen section involves histological examination of the margins of the excised
specimen at the time of surgery to ensure that they are tumour-free. If no tumour cells are
detected, the eyelid is reconstructed; if some are present in a particular area, further excision
is performed until the specimen is tumour-free.

Mohs micrographic surgery involves layered excision of the tumour. Specimens around the
eye are usually examined frozen as the fixing paste used in the technique as initially
described produces ocular irritation. Processing of each layer enables a map of the edges of
the tumour to be developed. Further tissue is taken in any area where tumour is still present
until clearance is achieved. Although time-consuming, this technique maximizes the chances
of total tumour excision whilst minimizing sacrifice of normal tissue. This is a particularly
useful technique for tumours that grow diffusely and have indefinite margins with finger-like
extensions, such as sclerosing BCC, SCC, recurrent tumours and those involving the medial
or lateral canthi. However, the irregular contours around the eyelids and extension of tumours
into orbital fat can make interpretation difficult, and specialist training is required in this
technique.

Chalazion Excision
A chalazion (meibomian cyst) is a chronic, sterile, granulomatous inflammatory lesion
caused by retained sebaceous secretion leaking from the meibomian or other sebaceous
glands into adjacent stroma. A chalazion secondarily infected is referred to as an internal
hordeolum.

Excision: The eyelid is everted with a special clamp, the cyst is incised vertically and its
contents curetted through the tarsal plate.
Incision and curettage of chalazion from the conjunctival side.

Blepharoplasty
A surgical procedure used for the correction of eyelid defects, deformities and disfigurations.
The symptoms which patients present for blepharoplasty include a feeling of heavy eyelids,
restriction of visual fields especially looking upwards, pressure on lashes and sometimes
visual axis blocked the visual axis, headache due to constant lifting of the eyebrows. In the
lower eyelid an appearance of bagginess and puffiness usually occurs due to the prolapse of
fat and wrinkles. Blepharoplasty procedures include;
 Upper lid blepharoplasty ( variations include excision of skin alone, excision of skin
and partial excision of prolapsed fat pads, ptosis correction with blepharoplasty)
 Lower lid blepharoplasty ( variation include Trans-conjunctival, transcutaneous)

PTERYGIUM EXCISION SURGERY

Wing-shaped benign conjunctival growth which grows unto the cornea, usually medial, in
sun exposed area i.e. interpalpebral fissure. Signs and symptoms include irritation, pain,
redness, itching and tearing. Visual impairment from Astigmatism Obstruction of visual axis
Diplopia. Indications for pterygium excision
• Recurrent, disturbing symptoms of irritation and dry eye
• Visual impairment
• Cosmesis (Visible mass that may be cosmetically unacceptable)

Types of pterygium surgery

Different techniques have different rates of success and recurrence, with conjunctival
autografting having the lowest rate of recurrence.
• Bare sclera excision (This procedure involves the excision of the pterygium while allowing
the bare sclera to re-epithelialize. This procedure has a relatively high recurrence rate)

• Excision with use of adjunct therapy e.g. mitomycin C, 5 Fluorouracil, Anti VEGF
(Avastin) drugs are used in this procedure to prevent recurrence.
• Excision with primary conjunctival closure (free edges of conjunctiva secured together,
effective only if defect is very small)

• Excision with conjunctival autograft (a free graft usually from superior bulbar conjunctiva,
is excised to correspond to wound, it is then moved and sutured into place. Can be performed
with inferior conjunctiva to preserve the superior conjunctiva)

• Excision with amniotic membrane graft (useful for very large conjunctiva defects as in
primary double headed pterygium or to preserve superior conjunctiva for future glaucoma
surgeries. Amniotic membrane possesses anti-scaring and anti-inflammatory properties,
which may be useful for treating pterygium. This method also minimises the risk of injury to
the conjunctival surface).
Surgical technique of pterygium excision : A, dissection of head from the cornea; B, excision
of pterygium tissue under the conjunctiva; C, direct closure of the conjunctiva after
undermining; D, bare sclera technique–suturing the conjunctiva to the episcleral tissue; E,
free conjunctival graft after excising the pterygium.

RETINAL REPAIR SURGERIES

A retinal detachment (RD) describes the separation of the neurosensory retina (NSR) from
the retinal pigment epithelium (RPE). This results in the accumulation of subretinal fluid
(SRF) in the potential space between the NSR and RPE.

Pneumatic retinopexys

Pneumatic retinopexy is an outpatient procedure in which an expanding gas bubble is used to

seal a retinal break and reattach the retina without scleral buckling. The most frequently used
gases are sulphur hexafluoride (SF6) and the longer-acting perfluoropropane (C3F8).
Pneumatic retinopexy has the advantage of being a relatively quick, minimally invasive,
‘office-based’ procedure. However, success rates are usually slightly less than those
achievable with conventional scleral buckling surgery. The procedure is usually reserved for
treatment of uncomplicated RD with a small retinal break or a cluster of breaks extending
over an area of less than two clock hours situation in the upper two-thirds of the peripheral
retina.

Scleral Buckling
Scleral buckling is a surgical procedure in which a material sutured onto the sclera (explant)
creates an inward indentation (buckle). Its purposes are to close retinal breaks by apposing
the RPE to the sensory retina, and to reduce dynamic traction at sites of local vitreoretinal
adhesion. The technique favourably alters the geometry and physiology of the eye to help
close and maintain closure of retinal breaks. Explants are made from soft or hard silicone. In
order to adequately seal a retinal break it is essential for the buckle to have adequate length,
width and height. It is also important for the buckle to involve the area of the vitreous base
anterior to the tear in order to prevent the possibility of subsequent reopening of the tear and
anterior leakage of SRF. There are three types of scleral buckling surgery;
Encircling circumferential buckle: Used in cases with retinal breaks in three or more
quadrants, diffuse retinal pathology (for example lattice degeneration) or when there is
concern about possible unidentified breaks. These buckles are placed parallel to the limbus

Segmental circumferential buckle: Used in cases where the retinal breaks span less than 6
o’clock hours and breaks are identified and treatable with cryotherapy or laser retinopexy.
These buckles are placed in parallel to the limbus.

Radial buckle: Used in cases with a single retinal break in an easily accessible location.
Often for a large flap tear. These buckles are placed perpendicular to the limbus. A radical
buckle may also added to an encircling buckle in cases where the retinal tear is irregular or
exhibits rolled edges.

Diagram depicting scleral buckling and subretinal fluid (SRF) drainage.

Cryopexy
In this procedure, cryotherapy (freezing) is used to seal off a small area of retinal detachment.
Uses nitrous oxide to freeze the tissue behind the retinal tear. This prevents fluid from
passing through the hole.

Laser Photocoagulation
If the retina is torn or the detachment is slight. Laser can be used to burn the edges of the tear
and halt progression. It also stimulates the scar tissue formation to seal the edges of the tear.
Vitrectomy
A surgical procedure that involves the removal of the vitreous humor gel (a fluid that fills the
eye cavity) to provide a better access to the retina. This allows for a variety of repairs
including the removal of scar tissue and laser repair of retinal detachment. The Pars plana
vitrectomy approach is employed in complicated cases of retinal detachment such as those
associated with giant retinal tears, retinal dialysis and massive vitreous traction.

Three-port pars plana vitrectomy using divided system approach

PRE AND POST SURGICAL ASSESSMENTS
Indications for cataract surgery
• Vision improvement is by far the most common indication for cataract surgery. Operation is
indicated only if and when the opacity develops to a degree sufficient to cause difficulty in
performing essential daily activities.

• Medical indications are those in which a cataract is adversely affecting the health of the eye,
for example, phacolytic or phacomorphic glaucoma. Cataract surgery to improve the clarity
of the ocular media may also be required in the context of fundal pathology (e.g. diabetic
retinopathy) requiring monitoring or treatment.

• Visually significant cataract, Decreased visual acuity deemed significant by patient

• Glare

• Decreased contrast sensitivity

• Cosmesis

Cataract surgery: Pre-op Assessment

Aim of pre-op assessment is to address the following:
• Does the lens opacity correspond to the visual impairment?
• Will lens removal provide sufficient functional improvement to warrant surgery?
• Is the patient sufficiently healthy to tolerate surgery?
• Is the patient or another responsible person capable of participating in post-operative care?

Cataract surgery: Pre-op Assessment

• Presenting complaints & history of presenting complaints
• Usually gradually progressive vision loss (may be sudden in traumatic cataract)
Ocular history:
• History of ocular trauma, infections, glaucoma, previous inflammation, retinal disease,
amblyopia, previous eye surgery
• History of spectacle use
• Past records may document the patients VA prior to development of cataract.
• If the patient has had surgery in the fellow eye, it is important to obtain information about
the
preoperative and postoperative course.

Ophthalmic preoperative assessment for cataract surgery

1 Visual acuity is usually tested using a Snellen chart. Distance and near, with spectacles and
pinhole.

2 Cover test. A heterotropia may indicate amblyopia, which carries a guarded visual
prognosis, or the possibility of diplopia if the vision is improved. A squint, usually a
divergence, may develop in an eye with poor vision due to cataract, and lens surgery alone
may straighten the eye.

3 Pupillary responses. Because a cataract never produces an afferent pupillary defect, its
presence implies substantial additional pathology likely to influence the final visual outcome
and requires further investigation.

4 Ocular adnexa. Dacryocystitis, blepharitis, chronic conjunctivitis, lagophthalmos,

ectropion, entropion and tear film abnormalities may predispose to endophthalmitis and
require effective preoperative resolution.

5 Cornea. Eyes with decreased endothelial cell counts have increased vulnerability to
postoperative decompensation secondary to operative trauma. Specular microscopy and
pachymetry may be helpful in assessing risk, and special precautions should be taken to
protect the endothelium.
6 Anterior chamber. A shallow anterior chamber can render cataract surgery difficult.
Recognition of a poorly dilating pupil allows intensive preoperative mydriatic drops, planned
mechanical dilatation prior to capsulorhexis and/or intracameral injection of mydriatic. A
poor red reflex compromises the creation of an adequate capsulorhexis, but can be largely
overcome by staining the capsule with a dye such as trypan blue 0.06% (VisionBlue).

7 Lens. Nuclear cataracts tend to be harder and may require more power for
phacoemulsification, while cortical opacities tend to be softer. Black nuclear opacities are
extremely dense and extracapsular cataract extraction rather than phacoemulsification may be
the superior option. Pseudoexfoliation indicates a likelihood of weak zonules (look for
phakodonesis), a fragile capsule and poor mydriasis.

8 Fundus examination. Pathology such as age-related macular degeneration may affect the
visual outcome. Ultrasonography may be required, principally to exclude retinal detachment
and staphyloma, in eyes with very dense opacity that precludes fundoscopy.

9 Current refractive status. It is critical to obtain details of the patient's pre-operative

refractive error in order to guide intraocular lens implant (IOL) selection. The keratometry
readings should be noted in relation to the refraction, particularly if it is planned to address
astigmatism by means of targeted wound placement or a specific adjunctive procedure. It is
particularly important to obtain a postoperative refractive result from an eye previously
operated upon so that any ‘refractive surprise’, even if minor, can be analysed and taken into
account.

Medical History
• All medical problems should be noted especially, DM (Diabetes Mellitus), IHD (Ischaemic
heart disease), COPD (chronic obstructive pulmonary disease), Bleeding disorders.
• Awareness of musculoskeletal disorders that limits the patient’s ability to lie comfortably on
the operating table should be noted
• If patient has had refractive surgery, it is helpful to obtain information about the type of
procedure, original refraction, original keratometry, intraoperative complications that might
have occurred, and whether the postop refraction is stable. This information is useful both on
predicting the IOL power and in determining the surgical approach.
• Drug History (Ocular and systemic medication)
• Any drug sensitivities and medications which might alter outcome of surgery, Such as
immunosuppressants and anticoagulants. Medication allergies should be noted and patients
questioned regarding sedative, narcotics, anaesthetic, or iodine or sensitivity.

Social History
• Occupation, Lifestyle, family support system, alcohol, tobacco and other drug use (related
to ocular conditions, post op recovery and rehabilitation)

Physical examination
• General health of patient
• Musculoskeletal abnormalities and limitations e.g. kyphosis (spine deformity), obesity, head
tremor
• Look out for difficulty breathing, cough

Pre-op Assessment
• Routine lab investigations including
• FBC
• BUE and creatinine
• ECG
• FBS
• These tests are not known to improve visual function after surgery. They are indicated when
necessary.

Patient Counselling
Patient should have a clear understanding of the risks and benefits of cataract surgery. The
patient and eye health worker should discuss:
• Indications for and alternatives to surgery as well as the likelihood of visual improvement
• The risk of common operative and post-operative complications
• The anticipated time course for activity limitations and reasonable expectations for the
patients return to regular daily activities
• The role of pre-existing ocular and medical disorders on visual outcome.
• The desired post op refractive status
• When the final optical correction will be given
• The frequency and duration of post op eye medications.

If the patients and their caregivers are adequately prepared prior to surgery, they can
anticipate a routine post op course and understand problems that may develop.

Cataract Surgery Complications:

Anaesthetic
• LA: Retrobulbar haemorrhage, globe perforation, damage to recti muscles, systemic spread
with cardiac arrhythmias and brainstem anaesthesia, etc.
• GA: Cardiac arrest, damage to larynx, broken teeth, hypersensitivity reaction to anaesthetic
agent etc.

Intra-op
• Premature AC entry and wound instability
• Damage to corneal endothelium, descemet membrane stripping
• Damage to iris
• Posterior capsule tear and vitreous loss
• Dropped Nucleus
• Choroidal haemorrhage

Cataract Surgery Complications

Early Post-op
• Endophthalmitis
• IOP related problems (raised IOP, low IOP and shallow AC)
• Corneal edema, striate keratopathy
• Corneal burn
• Cystoid macular edema (CME)
• Choroidal effusion

Late postoperative
• Late endophthalmitis
• Wound astigmatism
• Glaucoma
• Bullous keratopathy
• Posterior capsule opacification
• Retinal detachment
• Subluxated or dislocated IOL

Postoperative Management of Cataract Surgery

After uncomplicated cataract surgery, patients can generally be discharged from the recovery
area once they are awake and alert with stable vital signs, demonstrate safe emergence from
any anaesthetic or sedative agents given and report minimal or no pain. Detailed written and
verbal instructions must be given to the patient and any escort available with the patient.
There should be a definite plan for a follow-up appointment and contact information to reach
the operating physician and/or a designated medical partner who is qualified to care for the
patient if that physician is unavailable.

Follow-up visits should be tailored to individual patient risk factors with adjustments to
appropriately address and manage any complications. Follow up after uncomplicated
sutureless phacoemulsification surgery should be aimed at the detection of treatable,
asymptomatic complications such as elevated IOP because other serious complications are
virtually impossible to predict at a pre symptomatic stage. Immediate self-referral could be
used to assess and treat symptomatic issues.

Additional factors affecting the frequency and timing of postoperative visits include the size
and type of incision, the need to remove sutures, management of postoperative inflammation
and modifications for coexisting ocular comorbidities requiring closer follow-up. Interval
patient history, visual acuity, IOP measurement and slit lamp examination should be included
in each postoperative examination. A dilated fundus examination and additional diagnostic
testing should be performed if clinically applicable, especially if postoperative visual acuity
is less than expected. Optical coherence tomography (OCT) and/or fluorescein angiography
can evaluate macular diseases such as cystoid and diffuse macular edema, epiretinal
membranes and age-related macular degeneration (AMD). Similarly, corneal topography can
diagnose irregular corneal astigmatism and an automated visual field examination may help
characterize a neuro-ophthalmic abnormality. Other testing may be helpful in the right
clinical setting.

POSTOPERATIVE RESTRICTIONS

Postoperative activity restrictions vary per physician. Some physicians recommend protective
shielding on the day of surgery and in the evenings for the first week. Many advocate
limitations on heavy lifting and bending to allow wounds more time to strengthen before any
physical strain. Surgeons often restrict bathtub immersion in water. If applicable, other
limitations could include no chlorinated pools or ocean swimming until given clearance by
the surgeon. Limitation on eye makeup during the immediate postoperative period is also
common.

Some clinicians are beginning to challenge the routine use of postoperative shields for
protection after uncomplicated modern cataract surgery. Lindfield et al. suggested in a
retrospective study that recent advances in wound construction, improved surgical outcomes
and decreased complication rates may make shields no longer necessary.

Another study published in 1991 examined a group of postoperative cataract patients

instructed only to refrain from activities that produced pain. No shield was required, and no
instructions were given to restrict common daily activities such as showering and hair
washing. This study found no complications related to any postoperative activity]. Additional
research assessing the impacts of different postoperative restrictions on outcomes would help
guide clinicians to further optimize care in the future.

POSTOPERATIVE MEDICATION REGIMEN

Similar to restrictions, postoperative regimens of topical antibiotics, corticosteroids and

NSAIDs vary widely among practitioners. There are no controlled investigations that
establish an optimal regimen for the use of topical agents. It is the decision of the operating
surgeon to use any or all of these medications. Potential complications of postoperative
medications must be considered. Allergic reactions to antibiotics can be severe. Elevated IOP
with corticosteroids is possible with steroid responders, often younger, highly myopic
patients or those with glaucoma. Significant corneal reactions, including epithelial defects
leading to stromal ulceration and melting, have rarely been reported with topical NSAIDs.

Topical antibiotics

Antibiotics are used to reduce the risk of postoperative endophthalmitis. Recent surveys from
the Association of Veterans Affairs Ophthalmologists (AVAO) and the American Society for
Cataract and Refractive Surgery (ASCRS) showed that 100% and 98% of respondents,
respectively, used topical antibiotics in the postoperative setting. Recent studies suggest that
the initiation of antibiotics should begin immediately after surgery rather than delaying until
the first postoperative day. Surgeons must also be aware of evolving resistance to antibiotics,
as multidrug-resistant bacteria are now present in the majority of patients undergoing
routine cataract surgery]. Staphylococcus species is the most common organism implicated in
acute postoperative infectious endophthalmitis and has demonstrated increasing resistance to
many antibiotics, including the latest generation fluoroquinolones.

To reach higher intraocular antibiotic concentrations, recent studies including one by the
European Society of Cataract and Refractive Surgeon (ESCRS) have advocated the use of an
intracameral antibiotic such as cefazolin or cefuroxime at the end of each case to supplement
the topical antibiotics prescribed after surgery in prophylaxis against endophthalmitis ]. There
is some evidence to support the use of injecting subconjunctival antibiotics at the conclusion
of surgery, although there is a potential risk for intraocular toxicity due to leakage through
surgical cataract incisions when aminoglycosides are used

Topical corticosteroids

Corticosteroids are used to control postoperative inflammation. Clinically, this is commonly

seen as cystoid macular edema (CME). Surgical factors such as longer operative times, prior
surgery, extensive procedures and younger age may be associated with increased
inflammation. Patients with small incision phacoemulsification cataract surgery often have
little inflammation after 4 weeks of treatment with topical corticosteroids. Patients with larger
wounds requiring manual expression of the nucleus can have visible inflammation for up to 8
weeks. Diabetic patients may show more prolonged postoperative inflammation due to
increased compromise of the blood–aqueous barrier.
Topical nonsteroidal anti-inflammatory drugs

Prior studies have suggested that NSAIDs can be used to maintain pupillary dilatation during
surgery, decrease perioperative pain and help decrease the incidence of postoperative cystoid
macular edema. Although evidence does support the perioperative use of NSAIDs to prevent
CME in high-risk eyes, there is no published evidence that routine use results in improved
final visual outcomes. Evidence does suggest that NSAIDs alone or in combination with
corticosteroids are more effective than corticosteroids alone in preventing and treating acute
and chronic CME. A recent prospective randomized clinical study reported that both
bromfenac 0.09% and nepafenac 0.1% were well tolerated and resulted in positive outcomes
in the treatment of pain and inflammation after cataract surgery.

Topical NSAIDs such as nepafenac, ketorolac and diclofenac have been reported to cause
corneal melt in the setting of epithelial breakdown. It is best to stop or taper these
medications as soon as they are no longer necessary. Although there is some evidence that
concomitant use of topical corticosteroids with NSAIDs may reduce incidence of this
complication, some contend it is still advisable to minimize or avoid the use of topical
NSAIDs, especially as a single agent.
Indications for Glaucoma surgery
• IOP not controlled with maximum medical therapy
• Failure of medical treatment i.e. rapidly progressing optic nerve damage or visual field
damage despite medical treatment
• Medical therapy not affordable or accessible
• Intolerable side effects with medical therapy
• Patient not compliant with medical therapy
• As a primary procedure in childhood glaucomas e.g. congenital glaucoma, where medical
therapy is known to be ineffective in the long term as well as in adult glaucoma.
• Treatment should be individualized with no fixed rule

General principle: When IOP is raised to a level that there is evidence of progressive
VF or ON changes which will threaten the quality of visual function, despite adequate
medical treatment

Glaucoma surgery: Pre-op Assessment

Aim of preop assessment is to address the following:
• Determine type and stage of glaucoma
• Is the proposed surgery suitable for the eye to be operated? E.g. trabeculectomy not suitable
for someone with extensive conjunctival scarring, goniotomy not suitable for angle closure.
• Is the eye healthy enough to tolerate surgery?
• Is the patient sufficiently healthy to tolerate surgery?
• Is the patient or another responsible person capable of participating in post-operative care?

Glaucoma surgery: Pre-op Assessment

• Presenting Complaints & history of presenting complaints
• Usually gradually progressive vision loss
Ocular history:
• History of ocular trauma, infections, previous inflammation, cataract, retinal disease,
previous eye surgery.
• History of spectacle use
• Past records may document previous visual field test results, IOPs
• If the patient has had surgery in the fellow eye, it is important to obtain information about
the operative and postoperative course.

Medical History
• All medical problems should be noted especially DM (Diabetes Mellitus), IHD (Ischaemic
heart disease), COPD (chronic obstructive pulmonary disease), Bleeding disorders, adrenal
suppression caused by systemic corticosteroids.
• Awareness of musculoskeletal disorders that limits the patient’s ability to lie comfortably on
the operating table should be noted
• Use of medications e.g. antihypertensive medication, migraine treatment, sleep apnea.
Patients with these conditions have glaucoma that is usually difficult to control.
• Family history of glaucoma
• Drug History (Ocular and systemic medication)
• Any drug sensitivities and medications which might alter outcome of surgery, such as
immunosuppressants and anticoagulants. Medication allergies should be noted and patients
questioned regarding sedative, narcotics, anaesthetic, iodine or latex sensitivity. Use of oral
or inhalational steroids.
• Adverse effect to glaucoma medications
• Compliance to treatment, last medication use

Social History
• Occupation, Lifestyle, family support system, alcohol, tobacco and other drug use (related
to ocular comorbidities, post op recovery and rehabilitation)

Examination
• Visual Acuity
• Refraction
• Anterior segment examination
• Eyelids (entropion, ectropion, blepharitis or other infections e.g. stye)
• Conjunctiva (conjunctivitis, pterygium, previous filtering bleb)
• Cornea (clarity, opacities, oedema, vessels, abnormal tear film)
• Anterior Chamber (depth, cells)
• Iris (posterior synechiae, atrophy)
• Pupillary reaction
• Reaction to light, presence of RAPD
• Lens
• Careful lens examination to determine whether the lens is causing the glaucoma and
whether there is the need for combined glaucoma and cataract surgery e.g.in lens induced
glaucoma, POAG with significant cataract where the cataract is expected to progress post op
because of the use of steroids
• Dilated fundus examination (For signs of glaucomatous optic neuropathy and also to
determine the extent of optic nerve damage)
• Observe the scleral ring to identify the limits of the optic disc and evaluate its size.
• Identify the size of the various parts of the neuroretinal rim - ISNT Rule.
• Examine the retinal nerve fibre layer.
• Examine the region outside the optic disc for peripapillary atrophy.
• Look for retinal and optic disc hemorrhages

Ancillary Tests
• Visual field test (functional test of the optic nerve)
• Humphrey Standard Automated perimetry, Octopus.
• Optic nerve structural tests e.g. OCT.
• These are especially helpful in diagnosing optic nerve damage in early glaucoma
• Anterior Segment OCT
• Angle depth, structure
• Pachymetry

Post op Treatment
• Steroid eye drops
• Antibiotic eye drops
• Cycloplegic/Mydriatic eye drops

Complications of Trabeculectomy
Intraop complications
• Conjunctival button hole
• Scleral or corneal perforation
• Damage to iris
• Damage to lens with cataract formation
• Suprachoroidal haemorrhage
• Subconjunctival haemorrhage

Trabeculectomy complications

Early Post Op Complications

• Blebitis
• Endophthalmitis
• Shallow/Flat AC
• + High IOP/+ Low IOP
• Hyphaema
• Choroidal effusion
• Hypotony (with maculopathy & keratopathy)
• Wipe out Syndrome
• Cystoid macular oedema

Late Post Op Complications

• Endophthalmitis
• Failure from conjunctival/scleral scarring
• Visual field damage progression
• Cataract progression
• Astigmatism

Complications of Other Glaucoma Surgeries

• Same as for trabeculectomy
• Tube erosion, tube or plate migration, corneal oedema, corneal decompensation and
scarring.
• In surgeries where small implants are used the implant may get dislodged or blocked with
blood or vitreous

Postoperative care for Glaucoma Surgery

Before patients have a trabulectomy, they must be informed that the operation will not cure
the disease; it will lower the IOP in order to reduce the rate of deterioration of vision loss.
They must understand that any vision already lost cannot be regained through surgery and
that the surgery may cause initial blurring of vision in the immediate postoperative period
(and will resolve by itself overtime).

Good follow-up care is essential, and patients should be provided with a contact number to
call when they need to complain, ask for information or reschedule an appointment, or when
they notice any symptoms that could indicate a complication.

Postoperative care after trabeculectomy can be classified into immediate postoperative care
(0-6 weeks) and mid- to longer-term postoperative care (after 6 weeks)

Principles of immediate postoperative care (0–6 weeks)

Ensure that the aim of surgery has been achieved, i.e that the IOP has been lowered

One day after the operation (on day 1), the surgeon examines the eye to ensure that the
operation is achieving drainage of aqueous humour with adequate formation of a bleb and
satisfactory lowering of the IOP. The IOP on the first day postoperatively is not the final IOP
but serves as a good indication that a drainage channel has been successfully created. The
surgeon also examines the eye to look for early complications at this stage: infection,
hyphaema, conjunctival/wound leak, shallow/flat anterior chamber, hypotony requiring
intervention, and choroidal detachment.

Protect the eye from external injury

The operated eye is padded until the following day. If the other eye has no vision, the
operated eye is not covered but a perforated eye shield is placed on it instead.
Ensure hygiene and prevent infection

The patient should keep the face clean and avoid touching the eye. Patients may bathe and
shower, taking extra care not to bend forward orto touch the operated eye (which may also be
protected with an eye shield). Hands should be washed before instilling any eye drops.
Postoperative antibiotic eye drops (e.g. chloramphenicol) are prescribed for use 4–6 hourly or
4–6 times a day for 2–3 months.

Reduce inflammation associated with the operation

Some degree of redness and swelling may occur after the operation. Postoperative anti-
inflammatory eye drops (e.g. dexamethasone) are prescribed for use 1–2 hourly during the
first few days and subsequently reduced to 4–6 times a day. The postoperative eye drops may
be used for 2–3 months as advised by the reviewing doctor.

Control pain

It is usual to have some eye pain after glaucoma surgery but this is often mild and responds to
analgesics such as non-steroidal anti-inflammatory drugs and acetaminophen.

Symptoms and signs of complications (0–6 weeks)

A sudden loss of vision

A small reduction in vision, usually not more than 2 lines of visual acuity (VA), may occur
after surgery, but should improve gradually or at least not worsen rapidly. Rapid deterioration
of vision is an emergency; therefore it must be reported promptly. The following are common
causes.

1. A hyphaema indicates the presence of blood in the anterior chamber. This clogs the
trabecular meshwork and blocks the fistula created for drainage to the sub-
conjunctival space, causing the IOP to rise, sometimes catastrophically. This increases
damage to an already diseased optic nerve and may result in blindness if not promptly
reported and treated. Patients should report to the health facility where they had the
surgery for urgent management.
 Sudden loss of central vision may occur, especially in patients who had very severe
disease at the time of surgery. Surgeons sometimes make a decision to avoid
operating on such patients but instead offer other, less invasive, alternatives. Vision
loss may be gradual or rapid, depending on the severity of disease and postoperative
inflammation.

2. Choroidal detachment is caused by the passage of serum into the supra-choroidal

space (between the sclera and the choroid). It can present with quite severe loss of
vision with variable degrees of pain. An urgent B-scan ultrasound can help with the
diagnosis. Urgent treatment is needed to prevent permanent loss of vision.

Soft eye

This leads to a shallow or flat anterior chamber. It is usually caused by over-filtration due to a
loose scleral trabeculectomy flap, a conjunctival wound leak at the incision site, or a leak via
a conjunctival buttonhole. It may or may not present with reduction in vision, with little to
severe pain depending on the cause. Padding the eye may be sufficient, but urgent surgery is
sometimes necessary.

Redness, pain and discharge (pus)

This may be accompanied by a possible drop in VA very soon after surgery, and this
combination is usually indicative of an active infection. Redness alone may be normal
following surgery but if it persists beyond a few days it should be reported as it may mean an
active inflammation in the eye. All instances of the above symptoms should be reported
urgently to the health facility where they will be investigated and properly treated.

Principles of longer-term postoperative care (after 6 weeks)

Optimise vision

Six to eight weeks after the operation, refraction should be undertaken to assess the patient's
best-corrected visual acuity (BCVA) and to obtain a prescription for spectacle or contact lens
correction. Not everyone can wear/continue with contact lenses following trabeculectomy.
The doctor must assess the bleb and the suitability of contact lens wear.

Continue to protect the eye

Advise the patient about protecting their eye. Especially in sports, physical contact activity
and windy weather, the eye needs to be protected from injury with sports goggles (where
indicated) or UVB sunglasses during outdoor activities such as riding a motorcycle. The
protective eyewear should be kept clean.

Continue medication

When necessary, the postoperative medication (antibiotics and steroid eye drops) may be
continued for up to 3 months after surgery on advice of the doctor.

In some cases, anti-glaucoma medication may also be prescribed after the operation, if the
lowering of the IOP to the desired level has not been achieved. Patients should be made
aware of this possibility before surgery.

Be alert for signs of postoperative complications

The patient must be monitored regularly to detect any changes in vision, pain or any other
symptoms that will indicate postoperative complications such as infection, a failed bleb or
over filtration. The importance of community-based follow-up by the community health
worker or ophthalmic nurse cannot be overemphasised; this is essential in order to ensure that
symptoms and signs are recognised and treatment offered without delay. Patients should be
advised to get help if they notice any symptoms-see panel below.

Possibility of additional surgical procedures

When the IOP control is not at the desired level, the doctor may advise additional procedures
to optimise IOP control. These procedures may include the release of releasable sutures, bleb
revision, antimetabolite injections or even laser procedures.

Symptoms and signs of complications after trabeculectomy (after 6 weeks of surgery)

1. Redness associated with discharge (pus) from the eye. Long after a successful
trabeculectomy, bacterial infection could occur. A person who has had eye surgery
 and has discharge (pus) from the eye needs to be seen immediately by an eye doctor
and treated with the appropriate medication. Self-medication, especially with steroid
eye drops, must be avoided. Serious consequences and loss of vision could occur if
there is endophthalmitis.

2. Discomfort. A large drainage bleb may cause abnormalities in tear spread over the
cornea, causing poor tear films that cause a sensation of dryness and discomfort. Such
large blebs may also be uncomfortable under the eyelid causing cosmetic
embarrassment.

3. Cloudy vision and cataract. The chance of an eye developing a cataract increases
after trabeculectomy. The patient should be made aware of this. The patient may have
increasing glare in bright sunlight or while driving at night. Any reduction in vision
must be investigated to determine the immediate cause. Vision generally improves
following cataract surgery, except if the glaucoma damage is significant.

4. Changes in refraction: There may be astigmatism following trabeculectomy because

of the mild distortion of the eye's anatomy. This may manifest as a need for new
spectacles. Such change can be delayed until about 3 months after the operation, when
the eye has stabilised.

5. Continued loss of vision: Even with good IOP control, patients may still continue to
lose vision. The patient may see haloes around light bulbs which may indicate
cloudiness of the cornea due to raised IOP Glaucoma surgery reduces the rate of loss
of vision in glaucoma patients but may not completely halt it.

Advice for patients at discharge

Patients should be given information about the following before they go home after a
trabulectomy. They should also understand about the possible complications and understand
the importance of getting help urgently so that their vision can be preserved. Make sure that
patients have the contact information they need, e.g. the telephone numbers of the appropriate
person so that they can get an appointment as soon as possible.

How the eye will feel

You may have some watering, sandy sensation or blurring of vision after trabeculectomy, but
this should clear within a few days. Soreness and irritation may occur from the sutures or
because of the surgery itself. These sensations generally reduce within a few days.

Protection

The eye has now been operated on and is more fragile than before. It is important to take
special care and to protect your eye from injury. You can wear UVB sunglasses in the
daytime.

Caution with activity

Physical activities that require bending forward such as farming, ‘ruku’ and ‘sajda’
(prostration) during Muslim prayer and lifting of heavy items are to be avoided in the first six
weeks after surgery. Strenuous activities such as running, jumping, swimming and sex are
also to be avoided until the eye doctor advises it is safe to resume them.

Cleanliness and hygiene

 You can shower, have a bath or wash your face to ensure cleanliness.

 For at least one week, do not use eye make-up, including kohl and eye pencil.

 Avoid touching the eye directly or rubbing it.

Medication

 Wash hands before applying your eye drops.

 Do not touch the tip of the dropper of the eye drop bottle with fingers and do not
allow the tip of the bottle to touch the eye

 Use the eye drops as often as indicated on the bottle or as directed by your doctor.

Keeping appointments

It is important to keep your appointment, as the eye doctor will need to regularly monitor
your vision and eye pressure and look out for any signs of complications. Bring your eye
drops with you to the hospital.

IMPORTANT: Come back in case of any worrying signs or symptoms

Contact your community health worker (if you have one) or your eye nurse or eye doctor
immediately if you experience any of the signs or symptoms listed below-even if this is
several months after the operation – as these can indicate that there is a problem that needs to
be looked at. Coming back quickly will give medical professionals the best chance to save
your sight and your eye.

 Any pain: come back very urgently

 A rapid reduction in vision (particularly central vision): come back very urgently

 Redness and/or discharge (pus): come back very urgently

 Haloes around light bulbs: come back very urgently

 Blurry or distorted vision (including increased glare in sunlight or while driving at

night): less urgent, but can easily be corrected with a cataract operation or a new
spectacle prescription.

Indications for pterygium excision

• Recurrent, disturbing symptoms of irritation and dry eye
• Visual impairment
• Cosmesis

Pre-op Assessment
• Pre-op assessment is the same for other surgical procedures. In addition:
• History
• Symptoms of irritation
• Occupation (outdoor workers are at a greater risk of pterygium development and
progression)

Examination
• Refraction. Note type of astigmatism pre-op
• Look for hypertrophic scars and keloids on general exam

Ancillary Tests
• Corneal topography
• Pachymetry

Pre-op Assessment
Risk factors for recurrence of pterygium
• Race (African/Black)
• Young age
• Actively inflamed pterygium at time of surgery
• Large “fleshy” pterygium
• Presence of keloids or hypertrophic scars

Post-op management
• Steroid eye drops/ointment
• Antibiotic eye drops/ointment
• Post op refraction

Complications of pterygium surgery

Intraop complications
• Corneal abrasion
• Corneal perforation
• Scleral perforation
• Damage to medial rectus muscle

Early Post-op complications

• Scleral melt, Corneal melt. Especially with the use of antimetabolites mitomycin C, 5
fluorouracil.
• Persistent corneal epithelial defects
• Graft dislocation

Late Post-op complications

• Corneal scarring
• Recurrence of pterygium
• Astigmatism
• Graft failure

Preoperative assessment for Corneal Transplant

Pre-op assessment (history, comprehensive eye exam, investigations) should aim to evaluate
patient’s ocular condition and manage poor prognostic factors prior to PKP
• (Big 4 poor prognostic factors)
• Ocular inflammation
• Glaucoma
• Corneal vascularization
• Ocular surface abnormalities:
• Associated lid abnormality (entropion, ectropion)
• Tear film dysfunction and dry eyes

Assess visual potential

• Amblyopia
• Optic atrophy
• Retinal and macular conditions (e.g. cystoid macular edema)

K readings

Axial length

Baseline IOP

Early postoperative
• Glaucoma or hypotony
• Persistent epithelial defect
• Endophthalmitis
• Wound leak
• Recurrence of primary disease
 • Cataract
• Cystoid macular oedema

Late postoperative
• Rejection
• Infective keratitis
• Recurrence of disease
• Astigmatism
• Persistent iritis
• Late endothelial failure
• Retinal detachment

Causes of graft failure

1. Early failure (< 72 hours)
• Primary donor cornea failure
• Unrecognized ocular disease
• Low endothelial cell count
• Storage problems
• Surgical and postoperative trauma
• Handling
• intraoperative damage
• Recurrence of disease process (e.g. infective keratitis)
• Others : Glaucoma, Infective keratitis

2. Late failure (> 72 hours)

• Glaucoma
• Persistent epithelial defect
• Infective keratitis
• Recurrence of disease process
• Late endothelial failure
• Rejection (30% of late graft failures)
Factors which affect graft survival

• Factors associated with higher risk of graft rejection

• Young age
• Repeat grafts
• Exposed sutures
• Deep stromal vascularization
• Size of graft (large graft)
• Position of graft (eccentric graft)
• Presence of peripheral anterior synechiae

Other factors associated with graft failure

• Pre-existing glaucoma and high IOP
• Ocular surface (lids, tears)
• intraocular inflammation (iritis)

Postoperative Management of Corneal transplant Surgery

1. Topical steroids are used to decrease the risk of immunological graft rejection. After
initial
administration of 2-hourly and then reducing to four times daily, the dose may be further
tapered, depending on the condition of the eye. Steroids are, however, usually continued
long-term at low intensity, such as once daily for a year or more.

2. Other immunosuppressants such as oral azathioprine and topical and systemic

ciclosporin may be used for prevention of rejection, but are usually reserved for high-risk
patients.

3. Mydriatics two times daily for two weeks, or longer if uveitis persists.
4. Oral aciclovir may be used in the context of pre-existing herpes simplex keratitis to
minimize the risk of recurrence.

5. Monitoring of IOP is performed during the early postoperative period with a Tono-Pen
because Goldmann applanation tonometry is unreliable.

6. Removal of sutures when the graft-host junction has healed. This is usually after 12–18
months, although in elderly patients it may take much longer. Removal of broken or loose
individual sutures is performed as soon as identified, to avoid promoting rejection.

7. Rigid contact lenses may be required to optimize visual acuity in eyes with astigmatism

Post Ocular Surgery Refractive Changes

The effect of ocular surgery on refractive outcome depends on the sequence of surgeries. For
example better refractive outcome is achieved if phacoemulsification is performed after
trabeculectomy. Glaucoma surgery is aimed at reducing IOP. This decrease in IOP is
associated with changes in several ocular factors including the axial length of the eye. This is
also relevant when glaucoma surgery and phacoemulsification are done in the same eye. One
study compared the eyes that underwent phacoemulsification at least three months after
trabeculectomy with the eyes that did not undergo glaucoma surgery and reported that the
changes in IOP is negatively correlated with refractive surprise (A refractive surprise is the
failure to achieve the intended post-operative refractive target); a correlation between lower
postoperative IOP or greater IOP reduction and axial length reduction was expected. Another
retrospective analysis showed favourable refractive outcomes in patients undergoing
simultaneous cataract extraction with trabeculectomy or glaucoma drainage device surgery.

When an eye is extremely myopic or extremely hyperopic before cataract extraction surgery,
then a refractive surprise should be anticipated. With conventional lens power calculations,
even when the appropriate formula is used for extreme myopes and extreme hyperopes,
patients can end up hyperopic. So calculations have to be adjusted accordingly for extreme
cases, targeting a bit of residual myopia after cataract surgery. Refractive surprise is also
expected in patients who have previously undergone PRK or LASIK surgery. Additionally
there can be surprises in post-penetrating keratoplasty patients and in cases where the anterior
segment of the eye is disproportionately sized compared to the overall length of the eye.

Postoperative changes in refraction are expected in the majority of patients following surgical
procedures for retinal detachment. The surgical technique appears to influence these changes.
The episcleral-encircling buckle is utilized frequently for retinal surgery. The most severe
cases of distortion of the globe occur with additional segmental buckle. The probable
mechanism for changing the refractive error is elongation of the globe by the pressure of
equatorial band.

Retinal surgery can induce significant refractive errors. These error include spherical changes
caused by alteration in axial length after scleral buckle placement, astigmatic changes
induced by scleral buckle or vitrectomy and focal alterations in corneal curvature that can
significantly limit postoperative visual acuity

Most studies have found a significant induce myopia after scleral buckling surgery. The
amount of increased axial length depends on the height of encircling scleral buckle. The
amount if induced myopia has been reported to be greater in phakic eyes that aphakic eyes.
This is explained by anterior displacement of the lens and optical considerations from
refraction at spectacle plane. The various factors which modify the refractive changes in these
cases are the size of the encircling element and the height that it induces in the retina. The
height of the encircling element is dependent on the distance between the anterior and
posterior suture placement for the encirclage and also the tightness of the sutures. If the
distance between the anterior and posterior sutures placed in an encirclage is less, it will
induce a higher intend on the retina and hence shorten the eye. Similarly, if a tighter suture is
applied, then also the intend will be higher and hence, the anteroposterior diameter of the eye
gets sorter inducing hyperopia. However if we use wider encircling elements, the effect is
mostly compression in the center, which increases the axial length to cause myopia. It was
found that low to moderate buckle height resulted in -1.56D to -2.24 of change in phakic eyes
and -0.74 to -1.14 in aphakic eyes. High encircling element of 5mm indentation result in
hyperopic shift of +0.35D for phakic eyes and +0.59D for aphakic eyes. Low to moderate
buckles induce an increase in axial length while higher buckles shorten the axial length. The
refractive errors gradually diminished over the six-month follow up, with residual errors of -
0.50 to -1.00D remaining stable.
Segmental buckles produced astigmatism and of lesser magnitude than encircling elements.
Induced changes in corneal shape decreased gradually over time. Again, the size of the
buckle used, the tightness of sutures, placement of sutures and the anteroposterior location of
the buckle used in relation to the cornea all modify the induced refractive error. After
encircling with additional segmental buckling, the refractive astigmatism axis corresponds to
the segmental buckle. These findings thus implied that segmental buckle may induce
astigmatism, and this effect was greater when the buckle was placed closer to the cornea. In
one study irregular astigmatism was found to be more frequent, however the induced corneal
changes persisted for up to 6 months after surgery and gradually reduces over time.

The adjunct use of silicone oil can impose alterations directly, by the oil’s interaction with
other refractive elements of the eye, and indirectly through its effects on intraocular lens
power calculations for subsequent cataract surgery. Silicone oil has a higher refractive index
than vitreous. The refractive shift created by silicone oil depends on the status of the lens. In
a normal phakic eye, the silicone oil form a concave surface behind the lens, there by acting
as a minus lens inside the eye making the eyes hyperopic. Based on Gullstrand schematic eye
there is an increase of 8D hyperopia. In practice the shift has been shifting from no change to
+10D change, with an average of 6D. In aphakic eyes, the silicone oil produces a convex
surface, there by creating a myopic refractive shift. The amount of myopic shift depends on
the papillary aperture diameter. Based on the schematic eye calculation, a refractive shift
from +12.5D to +5.6D with an average of 7.4D has been observed in aphakic eyes filled with
silicone oil. The silicone oil tamponade with vitreous surgery are used as a temporary
procedure. Therefore refractive changes with silicone oil are not permanent.

Referral Letters
When making a referral to an ophthalmologist or other provider it is essential for the
optometrist to use a referral form and the message must be short, precise and to the point.
There is space for little more than the optometrist’s pertinent examination findings and
indication of what is expected of the practitioner to whom the patient is being referred.
However the use such forms has two advantages over the more formal, typed letter:
 I. Completing the form requires only a few minutes’ time, and is there convenient for
use for people who are referred to for urgent conditions and must see the practitioner
within a day or two.
II. The use of such a form makes writing a report so easy for the doctor to whom the
patient is referred that the optometrist almost always receives a reply.

When time is not a problem and when the situation requires a relatively detailed message, a
typed (computer-generated) letter is often preferable. In most cases, the typed letter need
include only four paragraphs and each paragraph will require no more than two or three
sentences. The following outline is suggested:

Paragraph 1: This paragraph identifies the patient, usually in terms of name, age and sex, and
indicate when the patient was examined and the nature of the patient’s chief complaint or the
reason for the examination.

Paragraph 2: This paragraph relates the pertinent optometric findings (i.e., the refractive
error, corrected visual acuity and any sigficant binocular findings).

Paragraph 3: This paragraph relates the pertinent ocular health findings. Normally, these will
be summarised in terms of the findings resulting from the external examination, internal
examination, tonometry, visual fields, and other pertinent findings.

Paragraph 4: This paragraph may or may not give the optometrist’s tentative diagnosis (or
clinical impression as is often called). It will usually indicate what the optometrist expect the
practitioner to do.

Although information concerning refractive findings may not seem important, in many cases
this information may be crucial; and if the optometrist does not provide it, the
ophthalmologist may have to take the extra time to do a refraction.

Patient Education and Counselling

Implicit in the role of an optometrist as a primary care practitioner is the concept that the
optometrist not only examines patients and provides treatment ( which also includes
arranging for treatments provided by other practitioners), but also counsels and educates the
patients. This is because in any problem oriented system of medical records, patient
education is an important aspect of any treatment plan.

Counselling and patient education are necessary in all aspects of optometric care. Patients
whose only problem is myopia, hyperopia, or astigmatism naturally expect the optometrist to
be able to provide information concerning these refractive anomalies. They often want to
know how the condition came about, whether it will progress with the passage of time, if
wearing glasses will help the condition or will make their eyes “weaker”, and even if they
might eventually go blind.

Patients who to be fitted with types of vision aids to which they are unaccustomed (example
contact lenses) have a right to expect the optometrist to fully inform them about the use of
these new forms of visual correction.

Patients who are being referred to other practitioners whether for problems of ocular health or
general health are particularly in need of counselling. A patient being referred because of
cataract will want to whether or when surgery will be necessary; what kind of anaesthetic will
be used; how long he or she will have to stay in the hospital and whether glasses, contact
lenses or intraocular lenses will be fitted after surgery. A patient being referred for general
health problem may want to know how the optometrist arrived at the diagnosis or at the
decision to refer, what may be expected in the way of medical or surgical treatment and what
the outcome or prognosis may be. In many cases, the optometrist will have to tread a fine line
between unduly alarming the patient and making the patient feel that the referral is
unnecessary.

Patient expect the optometrist to be able and willing to provide information not only
concerning their particular problems but on a wide variety of topics concerning vision.