True for diurnal variation of intraocular pressure (IOP) is: (A) IOP is usually low in the morning hours, (B) IOP is usually higher in the morning hours, (C) IOP variation is related to plasma acetylcholine level, (D) In normal eye lOP fluctuation is <10 mm of Hg.
Answer is B. Diurnal variation of IOP: Usually, there is a tendency of higher IOP in the morning and lower in the evening. This has been related to diurnal variation in the levels of plasma coisol. Normal eyes have a smaller fluctuation (< 5 mm of Hg) than glaucomatous eyes (> 8 mm of Hg). Reference :- A K KHURANA; pg num:-210