1.

ORTHOPTIC
(Medicine) relating to normal binocular vision. OR
The evaluation and nonsurgical treatment of visual disorders caused by imbalance of the eye
muscles, such as strabismus.

Orthoptics (from the Greek words ortho meaning "straight", and optikas meaning "vision" is a
discipline dealing with the diagnosis and treatment of defective eye movement and coordination
(such as nystagmus), binocular vision, and amblyopia by eye care professionals. There are five
areas of treatment for orthoptic problems:

 corrective lenses (spherical, cylindrical lens, prismatic and Fresnel lenses)

 strabismic-related orthoptics as an "eye exercise" is limited to the treatment of eye
coordination problems by increasing the range of binocular fusion.
 eyepatching
 pharmaceuticals, such as cycloplegics
 surgery

However the term orthoptics is sometimes used to refer simply to eye exercises which are a
component of strabismic-related vision therapy.

ORTHOPTISTS

Orthoptists are Eye care professionals who specialise in the diagnosis and management of
binocular vision problems alongside Ophthalmologists.Orthoptists are represented worldwide by
the International Orthoptic Association.

Orthoptics is usually studied as a primary or master's degree,or as a 2 to 4 years post graduate

training course. Orthoptists usually work in close cooperation
with Ophthalmologists, pediatricians, and sometimes neurologists. Continuing professional
development and registration is required in most countries.[6] Orthoptics is the science
concerned with ensuring that patients' eyes develop their full visual potential and keep working
together throughout life.

During the latter part of the nineteenth century, Javal, in France, started using ocular exercises
and training methods for squints, which were very time-consuming but sometimes effective.
After many years, in 1896, Javal wrote, ‘The first time that I revealed my methods to von Graefe
(the foremost ophthalmologist of his day) he astounded me by saying that people are not worth
the effort. Life's experience has shown me that von Graefe was correct.’

2. MADDOX ROD
This is not a rod but a series of cylindrical grooves ground usually into a coloured piece of glass
and mounted in a rim. (Originally it consisted of a single cylindrical rod.) It is used to measure
heterophoria by placing it in front of one eye of a subject viewing a spot of light binocularly. The
Maddox rod and eye together form a long streak of light perpendicular to the axis of the grooves
and this retinal image is so unlike the image formed in the other eye that the fusion reflex is not
stimulated. The eyes will then stay in the passive position. If there is a phoria the streak of light
will not intersect the spot of light. For horizontal phorias the rod axis is placed horizontally and
for vertical phorias, vertically. The amount and type of the phoria can be quantified by placing a
prism of appropriate power and direction in front of either eye such that the streak appears
superimposed on the spot of light. Alternatively, the angle of the phoria could be determined
using a Maddox cross and placing a rod in front of one eye; the phoria can be read directly by the
patient who indicates where the streak of light appears to cross the scale. The Maddox rod is also
used to detect or measure cyclophoria (Fig. M1)See passive position; Maddox rod test;
Thorington test.

The Maddox Rod Test is a type of dissimilar image test for ocular alignment. This subjective
test requires one Maddox rod to be placed in front of the patient’s eye. Bar or loose prisms can
be used to quantitate a horizontal or vertical deviation. It is important to remember that this test
will not differentiate between the presence of a phoria or tropia; only the cover-uncover test can
determine if a phoria or tropia is present.

The COMT Performance Areas lists the Maddox Rod Test as one of the potential skills a
candidate may be required to perform for the COMT Performance Test.

When measuring a phoria using a Maddox rod and bar or loose prisms, the direction of the red
line viewed by the patient is perpendicular to the direction of the red cylinders.
 • If Maddox rod is held horizontally Æ a vertical line results (use this orientation to
measure for esophoria and exophoria

• If Maddox rod is held vertically Æ a horizontal line results (use this orientation to
measure for hypophoria and hyperphoria)

Steps:

1. Patient wears best corrected Rx

2. Maddox rod is held in front of patient’s eye (select to measure the horizontal or vertical
deviation first)

3. Transilluminator is focused on the midline of the patient’s face

4. Explain to patient: “You will see a red line and a white dot. Is the dot superimposed on the
red line?”

• If the patent answers “Yes, the dot is superimposed on the line,” then no deviation is
present (proceed in checking the other orientation)

• If the patent answers “No, the dot is not superimposed on the line,” then a deviation is
present (proceed with identifying and quantifying the deviation by holding up loose
prisms in the proper orientation until the dot is superimposed on the line)
 3. EPICANTHIC FOLD
An epicanthic fold, epicanthal fold, or epicanthus is a skin fold of the upper eyelid, covering
the inner corner (medial canthus) of the eye. This lower fold of the upper eyelid gives the eyes of
certain East Asians an appearance which seems relatively narrower and almond-like compared to
those without such folds.
The term epicanthic fold refers to a visually categorized feature of the eyelid; however, there are
different underlying explanations of the causes. For instance, one theory is based on the fact that
the fold is almost always associated with absent to near-absent brow ridges and vice versa, thus
causing some to posit that the absent brow ridge is responsible for the occurrence of the fold.

Other names for this trait include plica palpebronasalis,palpebronasal fold,and Mongolian eye
fold.

Epicanthal fold: A fold of skin that comes down across the inner angle (canthus) of the eye. The
epicanthal fold is more common in children with Down syndrome and other birth defects than
normal children and so is of value in diagnosis. Although some dictionaries state that this eye
fold is found in peoples of Asian origin, this is not true. The normal Asian eyefold is continuous
with the lower edge of the upper eyelid and actually appears distinctly different than a true
epicanthal fold.

4. Prisms Cover Test

measurement of the deviation in strabismus by the alternate cover test combined with
neutralization for the deviation using prisms

• Look for any obvious tropia or abnormal head posture.

• If the patient wears glasses, check the lens types and the presence of prisms
• Shine a torchlight into the patient's eye from about 1/2 metres away and observe the
corneal reflexes for any tropia
• Perform a cover test for near (33 cm), 6 metres and distance (most examiners will only
expect to perform for near and 6 metres).
• Perform an alternate cover test for near (33 cm), 6 metres and distance. (As in
cover/uncover test, usually near and 6 metres are sufficient)
• Perform the prism cover test for near (33 cm) and distance. (The prism is placed over the
eye with manifest deviation with the apex in the direction of the deviation. Perform an
alternate cover test by moving the occluder from one eye to another. Observe the
movement of the eye behind the prism as it takes up fixation. Increase the prism strength
until there is no movement seen in the deviating eye when the other eye is covered.)
Tip 1: When testing for near, you may need the patient to hold the fixating target to allow
you free hand to perform the prism cover test.

Tip 2: To check the accuracy of the prism dioptre increase the prism power until the eye
movement is reversed and then reduce it until the movement stops.

• Perform the prism cover test with the glasses on.

• Ask to examine the ocular motility.

5. MADDOX WING TEST :

The Maddox Wing Test is robustly constructed and provides a quick and efficient near test.
Heterophoria, horizontal and vertical deviations, and the cyclophoria are made without change of
position being indicated on the one chart.

Maddox wing test instrument, made by Weiss, London, used to test for imbalances in binocular
vision, for example heterophoria; ie the tendency to squint.

• Quick and efficient binocular vision test for near heterophoria

• Measures horizontal, vertical & cyclophoria

• Robust construction

• Handle folds flat against unit

6. ELECTRORETINOGRAM(ERG)

ERG stands for "Electroretinogram". The ERG is the massed electrical response of the retina to
brief flashes of light. It is used in the diagnosis of retinal diseases. In contrast, the VEP measures
the signal that is received by the visual cortex.

The ERG is recorded using a small contact lens electrode that rests on the front surface of the
eye. It doesn't hurt. There's a series of electrodes in different sizes that can be used for very
young infants up to adults. The retinal is a collection of rod, cone, and neural cells which make
electrical signals which transmit visual information to the brain. By measuring the changes in
those signals, it is possible to determine how well the different cells in the retina are working.

In an ERG result, there is are two parts. Initially there is a negative phase called the a-wave,
which is the electrical response of the photoreceptor, which is where light gets converted to an
electrical signal. The second part is where the graph rises, called the b-wave. This is the response
of the post-receptor cells such as the bipolar cells and other neurons. This test make it possible to
pinpoint in different diseases the site of the disease's action.

Sample waveform extracted from an electroretinogram (ERG)

7. ELECTROCULOGRAM (EOG)

The polysomnographic measurement of eye movement by electrodes mounted adjacent to each

eye, which detect the electrical dipole produced by the retina. OR

A recording of the moving eye.

 8. SYNOPTOPHORE

A modified form of Wheatstone stereoscope used in orthoptic training.

Or

A type of major amblyoscope (Fig. S16).

9. CORNEAL REFLEX

The corneal reflex, also known as the blink reflex, is an involuntary blinking of
the eyelids elicited by stimulation (such as touching or a foreign body) of the cornea, or bright
light, though could result from any peripheral stimulus. Stimulation should elicit both a direct
and consensual response (response of the opposite eye). The reflex consumes a rapid rate of 0.1
second. The evolutionary purpose of this reflex is to protect the eyes from foreign bodies and
bright lights (the latter known as the optical reflex). The blink reflex also occurs when sounds
greater than 40-60 dB are made.

The reflex is mediated by:

 the nasociliary branch of the ophthalmic branch (V1) of the 5th cranial nerve (trigeminal
nerve) sensing the stimulus on the cornea, lid, or conjunctiva (i.e. it is the afferent).
 the 7th cranial nerve (facial nerve) initiating the motor response (i.e. it is the efferent).
 possibly mediated by a medullary center.
Use of contact lenses may diminish or abolish the testing of this reflex.

The optical reflex, on the other hand, is slower and is mediated by the cortex (outer covering) of
the occipital lobe of the brain. The reflex is absent in infants under 9 months.

The examination of the corneal reflex is a part of some neurological exams, coma. Damage to the
ophthalmic branch (V1) of the 5th cranial nerve results in absent corneal reflex when the affected
eye is stimulated. Stimulation of one cornea normally has a consensual response, with both
eyelids normally closing.