Pharmacological

aspects in
Ophthalmology
Dr Manzoor Ahmed
Qureshi
Professor
Ophthalmology.
ISRA University
Eye drops
 Eye drops- most common
 one drop = 5 µl
 volume of conjunctival cul-de-sac 7-10 µl
 measures to increase drop absorption:
-wait 5-10 minutes between drops
-compress lacrimal sac
-keep lids closed for 5 minutes after
instillation
Ointments
 Increase the contact time of
ocular medication to ocular
surface thus better effect
 Disadvantage: vision blurring
 The drug has to be high lipid
soluble with some water solubility
to have the maximum effect as
ointment
Peri-ocular injections
 They reach behind iris-
lens diaphragm better
than topical application
 E.g. subconjunctival,
subtenon, peribulbar, or
retrobulbar
 This route bypass the
conjunctival and corneal
epithelium which is
good for drugs with low
lipid solubility
(Antibiotics).
 Also steroid and local
anesthetics can be
applied this way
Intraocular injections
 Intracameral or
intravitreal
 E.g.
– Intracameral
acetylcholine
(miochol) during
cataract surgery
– Intravitreal antibiotics
in cases of
endophthalmitis
– Intravitreal steroid in
macular edema
– Intravitreal Anti-VEGF
for DR
Systemic drugs
 Oral or IV
 Factor influencing systemic drug
penetration into ocular tissue:
– lipid solubility of the drug: more
penetration with high lipid solubility
– Protein binding: more effect with low
protein binding
– Eye inflammation: more penetration
with ocular inflammation
Ocular
pharmacotherapeutics
Cholinergic agonists
 Directly acting agonists
 Group:(Parasympathomimetic)
– E.g. Pilocarpine 1-4%, acetylcholine (miochol),
carbachol (miostat)
– Uses: miosis, glaucoma
– Mechanisms:
 Miosis by contraction of the iris sphincter muscle
 increases aqueous outflow through the trabecular
meshwork by longitudinal ciliary muscle contraction
– Side effects:
 Local: diminished vision (myopia), headache,
cataract, miotic cysts, and rarely retinal detachment
 systemic side effects: lacrimation, salivation,
perspiration, bronchial spasm, urinary urgency,
nausea, vomiting, and diarrhea
Cholinergic
antagonists
 Group: Parasympatholytic
 E.g. Tropicamide 0.5-1%, cyclopentolate, homatropine
1% or 2%, scopolamine, atropine 0.5% or 1%
 Cause mydriasis (by paralyzing the sphincter muscle)
with cycloplegia (by paralyzing the ciliary muscle)
 Uses: fundoscopy, cycloplegic refraction, anterior
uveitis
 Side effects:
– local: allergic reaction, blurred vision
– Systemic: nausea, vomiting, pallor, vasomotor collapse,
constipation, urinary retention, and confusion
– specially in children they might cause flushing, fever,
tachycardia, or delerium
Adrenergic agonists
 Alpha-1 agonists
 Group: Sympathomimetic
 E.g. phenylepherine 2.5%
 Uses: mydriasis (without cycloplegia),
decongestant
 Adverse effect:
– Can cause significant increase in blood
pressure specially in infant and susceptible
adults
– Rebound congestion
– precipitation of acute angle-closure glaucoma
in patients with narrow angles
Adrenergic agonists
 Alpha-2 agonists
– E.g. brimonidine (Alphagan), apraclonidine
(Iopidine)
– Uses: glaucoma treatment, prophylaxis against
IOP spiking after glaucoma laser procedures
– Mechanism: decrease aqueous production, and
increase uveoscleral outflow
– Side effects:
 local: allergic reaction, mydriasis, lid retraction,
conjunctival blanching
 systemic: oral dryness, headache, fatigue, drowsiness,
orthostatic hypotension, vasovagal attacks
– Contraindications: infants.
Beta-adrenergic
blockers
 E.g.
– non-selective: timolol,
levobunolol, metipranolol,
carteolol
– selective: betaxolol (beta 1
“cardioselective”)
 Uses: glaucoma
 Mechanism: reduce the
formation of aqueous
humor by the ciliary body
 Side effects:
bronchospasm (less with
betaxolol), cardiac
impairment
Carbonic anhydrase
inhibitors
 E.g.Oral: acetazolamide, methazolamide,
dichlorphenamide.
 Uses: glaucoma, cystoid macular edema,
 Mechanism: aqueous suppression
 Side effects: myopia, parasthesia, anorexia, GI
upset, headache, altered taste and smell, Na
and K depletion, metabolic acidosis, renal stone,
bone marrow suppression “aplastic anemia”
 Contraindication: sulpha allergy, digitalis users,
pregnancy
– Topical Dorzolamide (Trusopt)
 Same side effects but lower
Osmotic agents
 Dehydrate vitreous body which
reduce IOP significantly
 E.G.
– glycerol 50% syrup (cause nausea,
hyperglycemia)
– Mannitol 20% IV (cause fluid
overload and not used in heart
failure)
Prostaglandin
analogues
 E.g. latanoprost (Xalatan), bimatoprost, travoprost, unoprostone
 Uses: glaucoma
 Mechanism: increase uveoscleral aqueous outflow
 Side effects: darkening of the iris (heterochromia iridis),
lengthening and thickening of eyelashes, intraocular
inflammation, macular edema
 Anti-inflammatory

corticosteroid NSAID
Corticosteroids
 Topical
– E.g. fluorometholone, remixolone,
prednisolone, dexamethasone, hydrocortisone
– Mechanism: inhibition of arachidonic acid
release from phospholipids by inhibiting
phosphlipase A2
– Uses: postoperatively, anterior uveitis, severe
allergic conjunctivitis, vernal
keratoconjunctivitis, prevention and
suppression of corneal graft rejection,
episcleritis, scleritis
– Side effects: susceptibility to infections,
glaucoma, cataract, ptosis, mydriasis, scleral
melting, skin atrophy
Corticosteroids
 Systemic:
– E.g. prednisolone, cortisone
– Uses: posterior uveitis, optic neuritis,
temporal arteritis with anterior ischemic
optic neuropathy
– Side effects:
 Local: posterior subcapsular cataract, glaucoma,
central serous retinopathy
 Systemic: suppression of pituitary-adrenal axis,
hyperglycemia, osteoporosis, peptic ulcer,
psychosis
NSAID
 E.g. ketorolac, diclofenac, flurbiprofen
 Mechanism: inactivation of cyclo-
oxygenase
 Uses: postoperatively, mild allergic
conjunctivitis, episcleritis, mild uveitis,
cystoid macular edema,
preoperatively to prevent miosis
during surgery
 Side effects: stinging
Anti-allergics
 Avoidance of allergens, cold compress, lubrications
 Antihistamines (e.g.pheniramine, levocabastine)
 Decongestants (e.g. naphazoline, phenylepherine, tetrahydrozaline)
 Mast cell stabilizers (e.g. cromolyn, lodoxamide, pemirolast, nedocromil,
olopatadine)
 NSAID (e.g. ketorolac)
 Steroids (e.g. fluorometholone, remixolone, prednisolone)
 Drug combinations
Antibiotics
 Penicillins
 Cephalosporins
 Sulfonamides
 Tetracyclines
 Chloramphenicol
 Aminoglycosides(gent
amicin,tobramycin)
 Fluoroquinolones(cipr
ofloxacin,ofloxacin)
 Vancomycin
Antibiotics
 Used topically in prophylaxis
(pre and postoperatively)
and treatment of ocular
bacterial infections.
 Used orally for the treatment
of preseptal cellulitis
e.g. amoxycillin with
clavulonate, cefaclor
 Used intravenously for the
treatment of orbital cellulitis
e.g. gentamicin,
cephalosporin, vancomycin,
flagyl
 Can be injected intravitrally
for the treatment of
endophthalmitis
Antibiotics
 Trachoma can be treated by
topical and systemic
tetracycline or
erythromycin, or systemic
azithromycin.
 Bacterial keratitis (bacterial
corneal ulcers) can be
treated by topical
cephalosporins,
aminoglycosides,
vancomycin, or
fluoroquinolones.
 Bacterial conjunctivitis is
usually self limited but
topical erythromycin,
aminoglycosides,
fluoroquinolones, or
chloramphenicol can be
used
Antifungals
 Uses: fungal keratitis, fungal endophthalmitis
 Polyenes
– damage cell membrane of susceptible fungi
– e.g. amphotericin B, natamycin
– side effect: nephrotoxicity
 Imidazoles
– increase fungal cell membrane permeability
– e.g. miconazole, ketoconazole
 Flucytocine
– act by inhibiting DNA synthesis
Antivirals
 Acyclovir
interact with viral
thymidine kinase
(selective)
used in herpetic keratitis
 Trifluridine
more corneal
penetration
can treat herpetic iritis
 Ganciclovir
used intravenously for
CMV retinitis
Ocular diagnostic
drugs
 Fluorescein dye
– Available as drops or
strips
– Uses: stain corneal
abrasions, applanation
tonometry, detecting
wound leak, NLD
obstruction, fluorescein
angiography
– Caution:
 stains soft contact lens
 Fluorescein drops can be
contaminated by
Pseudomonas sp.
Ocular diagnostic
drugs
 Rose bengal stain
– Stains devitalized epithelium
– Uses: severe dry eye, herpetic keratitis
Topical Drugs Used for
Diagnosis:
Fluorescin Dye
 Fluorescein strip: Orange yellow dye
– water soluble
Cobalt blue light

Eye with corneal ulcer Orange becomes green

– No systemic complications
– Beware of contact lens staining
Local anesthetics
 topical
– E.g. Proparacaine, 0.5% Tetracaine
0.5%
– Uses: applanation tonometry,
gonioscopy, removal of corneal
foreign bodies, removal of sutures,
examination of patients who cannot
open eyes because of pain
– Adverse effects: toxic to corneal
epithelium, allergic reaction rarely
 Anesthetics
 Example:
– Propracaine Hydrochloride 0.5% (Alcaine)
– Tetracaine 0.5%

Local anesthetics
 Orbital infiltration
– peribulbar or retrobulbar
– cause anesthesia and akinesia
for intraocular surgery
– e.g. lidocaine, bupivacaine
Other ocular
preparations
 Lubricants
– drops or
ointments
– Polyvinyl alcohol,
cellulose,
methylcellulose,
sodium
hyaluronate,
Carbomer gels.
– Preserved or
preservative free
Complications of
topical administration
 Mechanical injury from
the bottle e.g. corneal
abrasion
 Pigmentation:
epinephrine-
adrenochrome
 Ocular damage: e.g.
topical anesthetics,
benzylkonium
 Hypersensitivity: e.g.
atropine, neomycin,
gentamicin
 Systemic effect: topical
phenylephrine can
increase BP
Healthy eye
 Tears that lubricate—the tear
film—are constantly produced
by a healthy eye
TEAR PRODUCTION
 Lipid layer – Meibomian glands,
Glands of Zeis
 Aqueous layer – Lacrimal glands,
Glands of Krause & Wolfring
 Mucin Layer-- Goblet cells and
gland of Manz.
FUNCTIONS OF TEAR
FILM
 -Lubricates and moistens eye surface
 -Provides nutrients & oxygen to cornea
 -Washes away foreign bodies & debris
 - Protects against bacteria and viruses
(with help of enzyme, Lysozyme, B-
lysine and immunoglobulin).
 Maintain the clear vision
What is dry eye?
 • Dry eye occurs when our eye
does
not produce enough tears or
appropriate quality of tears
to keep
the eye healthy and
comfortable
Common eye
symptoms
 Irritation
 Redness
 Burning/ Stinging
 Itchy eyes
 Sandy- gritty feeling (foreign body sensation)
 Blurred vision
 Tearing
 Contact lens intolerance.
 Increased frequency of blinking
 Mucous discharge.
 Photophobia (less frequent symptom)
 Symptoms worsen in windy or air-conditioned environments.
– As day progresses.
– After prolonged reading, working on computers
Dry Eye: Main Causes
AQUS TEAR DEFICIENT DRY EYE EVAPORATIVE
(KCS/DES) DRY EYE
Pure KCS: LG Non-Sjogrens Meibomian gland
alone. synd. disease
Sjogrens synd: –Ageing Lid
Primary: Lac & –Menopause surfacing/blinking
salivary Gld. –Medicamentosa anomalies
Secondary: with –Cicatricial Contact lens
RA,SLE disease related
–Neurotrophic Chronic
keratitis allergy/toxicity
–Trauma:
Radiation/thermal

Clin Exp Optom 2001; 84: 1: 4-18

Diagnosis:
History, Examination and
Investigations
 Anterior segment examinations of
Lid, Conjunctiva & Cornea.
 Corneal reflexes,
 TFBT
 Tear meniscus,
 Filaments & mucus plaque
Ocular surface staining
FL. and Rose Bengal 1%
Schirmer’s test
 Measures the basic and reflex
secretion using a special filter
5mm wide and 35 mm long.
Schirmer test
 Without Anesthesia
– Measures Reflex Tear
Secretion (dry eye =
< 10mm wetting)
 With Anesthesia
– Measures Basal Tear
Secretion (dry eye
=< 5mm wetting)
Tear meniscus height
Lower lid tear
meniscus height (N: .3
-.4mm)
Management of Dry
Eye
Treatm en t

Tear rep lac em en t Tear P res ervation

A rtific ial tears P u n c tal P lu g s Late KCS

Thank you
Any question?