Study finds patients with lower preop visual acuity benefit more from non-AMD CNV membrane excision

Patients with worse baseline visual acuities particularly benefit from surgical excision of choroidal neovascular membranes not associated with age-related macular degeneration, according to a retrospective study.

G. William Aylward, FRCOphth, and colleagues at Moorfields Eye Hospital, London, and at University College London, reviewed outcomes for 52 eyes treated for non-AMD-related CNV between November 1997 and March 2003. Of these eyes, CNV was related to punctate inner choroidopathy in 21 eyes (40%), idiopathic causes in eight (15%), pathologic myopia in six eyes (12%), ocular histoplasmosis syndrome in one eye (2%) and other causes in 16 eyes (31%), according to the study.

Patients averaged 41 years of age. Of the 52 eyes initially treated, 41 (80%) had 24-month follow-up data available. Preoperatively, logMAR equivalent visual acuity averaged 1.1 and lesions averaged 1.2 disc areas in size. Postoperatively, visual acuity improved one line or more in 26 eyes (63%), remained within one line of preop in 10 eyes (24%) and decreased more than one line in five eyes (12%), according to the study.

Improvements in vision were associated with worse baseline visual acuity, the authors noted. Specifically, vision improved in 84% of eyes with a baseline visual acuity of 6/36 or less, but in only 31% of eyes with a baseline visual acuity more than 6/36, they said.

"No evidence of association between 2-year visual outcome and any other baseline factor under study was observed," they added.

The study is published in the May issue of British Journal of Ophthalmology.