Ophthalmology Facts from Previous Papers

·         Chorda Tympani Nerve passes between the internal jugular vein and internal carotid artery as it travels anteriorly.

·         The sytlomastoid foramen is found in the temporal bone between the mastoid process and the styloid.

·         The carotid canal is on the inferior surface of the petrous part of the temporal bone.

·         The jugular foramen is formed between the temporal and occipital bones.

·         The optic canal is situated in the sphenoid bone

·         The foramen ovale is found in the greater wing of the sphenoid

·         The pituitary fossa is part of the middle cranial fossa. It is formed by the body of the sphenoid bone. The dura mater forms its roof. The cavernous sinus is found on either side. It is bounded by the anterior and posterior clinoid processes.

·         The fifth cranial nerve provides sensation to the face except for a region around the angle of the mandible which is supplied by C2 and C3 in the form of the great auricular nerve.

·         Cataract does not impair the pupillary light reflex.

·         The infundibulum of pitutary connects to the tuber cinereum of hypothalamus.

·         Incongruous hemianopia occurs in lesion of the optic tract. Congruous hemianopia occurs if the lesion is in the optic radiation or the visual cortex.

·         Light adaptation takes about 5 minutes and dark adaptation about 20 minutes in the normal population. It is biphasic. The dark adaptation time is related to the time required to build up rhodopsin stores. Wearing red glasses can speed up dark adaptation because red light stimulate rods only minimally in the light.

·         In MS, ERG & EOG is normal but VEP is delayed..if both VEP & ERG are abnormal, it suggests that VEP is delayed secondarily to abnormal ERG.

·         Vogt white limbal girdle: Age related corneal degeneration.

Characterized by bilateral, narrow cresentic lines composed of chalky white deposits(present in Bowman’s membrane) in the interpalpebral fissure along the nasal& temporal limbus.

Type1: separated from limbus by clear interval

Type2: No clear zone in between

·         Mild blurring of central vision with drusen within Bruch membrane beneath RPE. Diagnosis – Macular degeneration.

·         Vit D deficiency asso with – Zonular cataract

·         Which does not maintain A-P stability of eyeball – Superior oblique

(AA AIIMS May 09 Q.170 : Answer given is – Suspensory ligament of eye ball)