Noreen B. Javornik

Laser-induced drusen reduction improves visual function at 1 year

OBJECTIVE To describe the relationship of laser-induced drusen reduction to change in visual function at 1 year among patients enrolled in the Choroidal Neovascularization Prevention Trial (CNVPT). DESIGN Comparison of groups with and without drusen reduction; follow-up of a randomized controlled trial. PARTICIPANTS Evaluations of drusen and visual acuity at baseline and at 1 year were performed for 351 eyes of the 432 eyes enrolled in the CNVPT Bilateral Drusen Study and Fellow Eye Study (81%). One hundred eighty-four eyes were assigned to observation, and 167 eyes were assigned to laser treatment. Eyes with conditions that precluded an analysis of drusen reduction, such as those that developed choroidal neovascularization (CNV) within the first year, are excluded from this analysis. METHODS Change in macular drusen between initial visit and after 1 year was assessed by side-by-side grading by evaluators masked to information on visual function. Visual acuity, contrast threshold, and critical print size were measured by certified visual function examiners. MAIN OUTCOME MEASURES Change in visual acuity is the primary outcome. Change in contrast threshold and change in critical print size are secondary outcome measures. RESULTS Laser-treated eyes with 50% or more drusen reduction at 1 year had more 1- and 2-line increases in visual acuity and less losses in visual acuity compared with laser-treated eyes with less drusen reduction or with observed eyes (P = 0.001). Similar improvements were noted for contrast threshold but not critical print size at 1 year. CONCLUSIONS Laser-induced drusen reduction is associated with improved visual acuity and contrast sensitivity in eyes at 1 year. Longer term effects of laser-induced drusen reduction on visual function require additional observation. The overall potential value of laser treatment in eyes with high-risk drusen requires consideration of not only short-term effects on vision but also the effects of CNV and atrophy on vision.

Risk factors for choroidal neovascularization and vision loss in the fellow eye study of CNVPT.

Purpose: To identify risk factors for the development of choroidal neovascularization (CNV) and vision loss in the Fellow Eye Study of the Choroidal Neovascularization Prevention Trial. Methods: Retrospective review of 121 patients enrolled in a multicentered, randomized, controlled trial. Patients had neovascular age‐related macular degeneration in one eye and more than 10 large drusen in the other eye. Records of patients randomly assigned to laser treatment or observation were reviewed through 4 years of follow‐up. Three candidate risk factors for the development of CNV and vision loss were evaluated. Results: Eyes with hyperfluorescent drusen on fluorescein angiography at 3 minutes appeared to have a decreased risk of CNV. Patchy choroidal filling was seen in 14% of patients. Eyes with patchy choroidal perfusion showed a higher risk of developing CNV that was not statistically significant, and the increased risk was present only in treated eyes. Reticular pseudodrusen were present in only three eyes. Conclusions: Reticular pseudodrusen were rare. Late drusen fluorescence may protect against the development of CNV.

Treatment of Subfoveal Choroidal Neovascularization-Reply

In reply We thank Dr Tiedeman for his careful reading of our article and his thoughtful comments. As we emphasized in our discussion, advising whether a particular patient should be treated with laser photocoagulation involves consideration of both short- and long-term effects of the treatment and characteristics of the patient such as the condition of the fellow eye. We and Dr Tiedeman are in agreement that the reason that group B patients are good candidates for immediate treatment is the reduced risk for severe loss of vision that begins at 12 months after treatment and endures for at least 3 additional years. This sustained period of lower risk for loss of vision outweighs, in our opinion, the period of increased risk immediately following treatment. Members of the Macular Photocoagulation Study Group are listed in the April issue of theArchiveson page 482.