RETINA AND VITREOUS . . . CONT.

Investigations

Amsler Grid: commonly held at normal reading distance with glasses on, assesses macular function

fluorescein angiography: see neovascularization, leaks

Management

non-neovascular ARMD

•monitor

•low vision aids e.g. magnifiers, closed-circuit television

•query – anti-oxidants

neovascular ARMD

•laser photocoagulation for neovascularization

•50% of choroidal neovascularization cannot be treated initially

•no definitive treatment for disciform scarring

•focal laser for macular edema

•photodynamic therapy with verteporfin: IV injection of verteporfin followed by low intensity laser to area of choroidal neovascularization;

Treatment of Age-Related Macular Degeneration with Photodynamic Therapy (TAP) Study Group indicate that for selected patients with subfoveal lesions in

ARMD with predominantly classic choroidal neovascularization, verteporfin treatment can reduce the risk of moderate vision loss for at least 1 year; this therapy cannot stop or reverse vision loss in all patients with ARMD; investigations are ongoing

BLURRED OPTIC DISC MARGINS

DRUSEN

German, plural for "granules"

"giant drusen": hyaline deposits at disc margin and in disc itself, commonly producing field defects

more common form is deposited in Bruch's membrane

(area separating inner choroidal vessels from retinal pigment epithelium)

seen with increasing age, retinal and choroidal degeneration and as a primary dystrophy

with drusen alone, vision is normal or near normal

MYELINATED NERVE FIBRES

a variant of normal in which the retinal nerve fibres are myelinated anterior to the cribriform plate

appear as white streaks extending from the cup and occasionally in retina remote from disc

Table 5. Differential Diagnosis of Blurred Optic Disc Margins