Incidence of conversion to neovascular age-related macular degeneration (nAMD); in untreated fellow eyes of patients who are treated for nAMD in 1 eye with anti–vascular endothelial growth factor agents provides important prognostic information; to clinically manage patients. New age-related macular degeneration (AMD); develops in about a quarter of fellow eyes to those treated for neovascular AMD with intravitreal anti-VEGF agents; according to a post hoc analysis of the VIEW 1 and VIEW 2 studies.

“But patients with neovascular AMD in one eye should be followed regularly to check for subtle clinical; and imaging findings indicating conversion in their fellow eye,” Dr. K. Bailey Freund from Vitreous Retina Macula Consultants of New York, New York told Reuters Health by email. “But early detection is critical, since eyes treated early in the disease course will likely experience better visual outcomes; than those diagnosed at a more advanced stage.”

Age-related macular degeneration

However, patients received no treatment in the fellow eyes unless after conversion to nAMD; when any treatment approved by heath authorities was given per the investigators’ discretion. However, the reported rates of conversion to choroidal neovascularization (CNV); in the fellow eye of patients with unilateral neovascular AMD are as high as 38.7% over 5 years; and some have suggested that systemic outcomes of intravitreal anti-VEGF therapy could reduce this risk.

Dr. Freund and colleagues examined the association between anti-VEGF medication; and the incidence of conversion to neovascular AMD in the unaffected fellow eyes of 1561 patients treated with intravitreal ranibizumab; or aflibercept in the VIEW 1 and VIEW 2 studies. Over the 96 weeks of follow-up, there were 375 cases (24.0%) of conversions to neovascular disease; in the fellow eyes of patients with neovascular AMD, with similar rates across medications and dosing regimens.

Eye had intraretinal fluid

However, in multivariable models, conversion rates were 20% higher with each decade of increasing age; 32% higher among women than among men, 28% higher when the study eye had intraretinal fluid at baseline, and 29% higher for each 10 sq mm increase in CNV lesion size in the study eye. But the incidence of fellow eye conversion increased with the number of baseline risk factors: from 7.5 conversions per 100 person-years at risk for 1 factor to 21.5 conversions per 100 person-years at risk for 6 or more factors.

“The high risk for fellow eye conversion in patients with neovascular AMD; in one eye highlights the need to explore prophylactic treatments beyond the rather modest protection provided by the Age-Related Eye Disease Study 2 nutritional supplements,” Dr. Freund said. “But until more effective preventative treatment exists, there is an unmet need for more reliable home-based monitoring systems.”