During fundus fluorescein angiography, the earliest event observed after dye injection is:

• A Complete filling of the central retinal artery
• B Capillary filling at the foveal avascular zone border
• C Laminar flow in the retinal veins
• D Patchy choroidal fluorescence (choroidal flush) ✓

Explanation

The choroid is supplied by the short posterior ciliary arteries, whose shorter course lets dye reach the choriocapillaris roughly half a second to one second before the central retinal artery, producing the patchy lobulated choroidal flush. Laminar venous flow appears next as dye layers along venous walls before full venous filling, and complete arteriovenous transit takes several seconds. Knowing this sequence allows timing of vascular occlusions and shunts on angiography.

Reference: Parsons' Diseases of the Eye, 22nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.