APR 08, 2011
Using data from the ANCHOR and MARINA trials, researchers retrospectively evaluated the characteristics of patients who lost ≥15 letters of visual acuity after two years of monthly ranibizumab therapy for wet AMD compared with those who gained ≥15 letters of visual acuity.
They found that the lesion characteristics most closely associated with vision loss included features more commonly associated with suppressed choroidal neovascularization, such as pigmentary abnormalities, atrophic scar, and CNV in the absence of leakage. An increased area of RPE abnormality and increased total lesion area were also associated with vision loss, while leakage, hemorrhage, and fibrosis were not.
As with other therapies for neovascular AMD, this retrospective review also identified several baseline characteristics that have been associated with the risk of vision loss, such as the patient's age and the size of the neovascular lesion. The authors believe these characteristics probably serve as surrogate markers for disease severity or chronicity and support the current recommendation that lesions should be treated as early as possible to ensure better overall outcomes.
Better vision at baseline was another characteristic associated with a greater likelihood of vision loss. One explanation for this association, the authors say, is that patients with good vision at baseline might have a difficult time improving three lines of visual acuity compared with the greater likelihood of losing three lines of visual acuity. The opposite is likely true for patients with poor vision at baseline.
The authors conclude that in the future, patients undergoing anti-VEGF therapy might benefit from new therapies currently under development for dry AMD that promote photoreceptor and retinal pigment epithelium survival, such as neuroprotective, anti-inflammatory, and visual cycle modulating agents, rather than additional therapies that specifically target CNV.