Question

What is the Thinnest part of neuro-retinal rim according to ISNT rule ?

• A. Inferior
• B. Superficial
• C. Temporal
• D. Medial

Answer 1

The Correct Option is C

The ISNT rule is a useful mnemonic in ophthalmology, primarily used to evaluate the neuro-retinal rim in the optic nerve head. According to this rule, the thickness of the neuro-retinal rim typically follows a specific order:

• Inferior
• Superior
• Nasal
• Temporal

This mnemonic helps in assessing the optic disc for early signs of diseases such as glaucoma. According to the ISNT rule, the temporal part of the neuro-retinal rim is the thinnest. Therefore, the thinnest part of the neuro-retinal rim according to the ISNT rule is:

Temporal