The Ophthalmology Committee of National Egyptian Guidelines, Ministry of Health and Ophthalmology 
Chair of the committee: Hany Nasr.

Committee members: Mohamed Salah, Essam  Eltokhi, Rania Gamal, Weam Obaid, Karim Rizk, Maged Maher, Ayman Elghonemy.

Contributors from outside the committee: Mustafa Azab.

➡️ABBREVIATIONS

NICU: neonatal intensive care unit

RAPD: relative afferent pupillary defect

IOP: intra-ocular pressure

ROP: retinopathy of Prematurity

➡️GLOSSARY

 Myopia: a condition in which the visual images come to a focus in front of the retina of the eye resulting in defective vision of distant objects.

Hyperopia: a condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects.

Stereopsis: is the perception of depth. It arises when objects behind and in front of the point of fixation (but within Panum fusional space) simultaneously stimulate horizontally disparate retinal elements. The fusion of these disparate images results in a single visual impression perceived in depth. A solid object is seen stereoscopically (in 3D) because each eye sees a slightly different aspect of the object.

Vergences: are binocular, simultaneous, disconjugated movements (in opposite directions, so that the angle between the eyes changes.

Convergence: is simultaneous adduction (inward turning) and divergence is outwards movement from a convergent position.

Fusional vergences: are motor responses that eliminate horizontal, vertical, and to a limited degree torsional image disparity.

Amblyopia: is diminution of vision occurring during the years of visual development secondary to abnormal visual stimulation or abnormal binocular interaction. It is usually unilateral but it can be bilateral. The diminished vision is beyond the level expected from the ocular pathology present.

Tropia: manifest deviation in which the visual axes do not intersect at the point of fixation.

Esotropia means inward eye deviation, an Exotropia means outward eye deviation, a hyper-tropia means upward eye deviation, and a hypo-tropia means downward eye deviation.

Nystagmus: is rhythmic, abnormal eye movements with a "slow" eye movement driving the eye off the target followed by a second movement that brings the eye back to the target. 

Duction: an eye movement involving only one eye. It may be adduction, abduction elevation, depression, intorsion, extorsion.

Anisocoria: is when the pupils are not the same size.

Coloboma: ocular defects of the eyelids, iris, lens, ciliary body, zonules, choroid, retina or optic nerve. It is typically located in the inferonasal quadrant of the involved structure. It can affect one eye or both eyes.

Ptosis: is when the upper eyelid droops over the eye. The eyelid may droop just a little, or so much that it covers the pupil. Ptosis can limit or even completely block normal vision.

Proptosis: is the protrusion of the eyeball from the orbit.

Hypoglobus: is the downward displacement of the globe in the orbit.

Hyperglobus: is the upward displacement of the globe in the orbit.

Diplopia: is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. It is also called double vision.

Accommodation: is the mechanism by which the eye changes the refractive power by altering the shape of the lens in order to focus objects in various directions.

Keratoconus: is an uncommon corneal disorder where the central or paracentral cornea undergoes progressive thinning and steepening causing irregular astigmatism.