Purpose: To investigate systematically various fundus changes in branch retinal arteriolar occlusion (BRAO) and their natural history.
Methods: The study comprised a cohort of 123 consecutive patients (135 eyes) with BRAO. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations, and at initial visit fluorescein fundus angiography.
Results: Probability estimates of retinal infarct still present were 89% 1 week after BRAO onset, 69% after 2 weeks, 67% after 3 weeks, 34% after 1 month, and 13% after 3 months. Optic disk pallor in the involved region developed in 21% within 1 month from onset, in 42% by 2 months, and in 65% by 3 months. Retinal arteriolar attenuation developed in 19% within 1 month from onset, and in 28% by 6 months. Arteriolar sheathing developed in 19% within 1 month and 25% within 12 months. Arteriolar emboli were found in 58%; 65% of those were at initial visit, in BRAO seen within 1 week of onset.
Conclusion: Most common cause of BRAO is embolism from the heart or carotid arteries; emboli usually get impacted at the arteriolar bifurcation. Migration and disappearance of retinal emboli is a common finding. Evolution of the retinal and optic disk changes is described.