Cataract surgery in high-risk age-related macular degeneration: a randomized controlled trial.
To investigate if cataract surgery causes progression, from high-risk early age-related macular degeneration (AMD) to choroidal neovascularization (CNV), in the postoperative period.
                Randomized controlled trial. Patients, with visually significant cataract and fundus features of early AMD at high risk of progression to CNV, were randomized into two groups and were evaluated at baseline and 6 months. The study patients (n = 27) underwent immediate cataract surgery. The control group (n = 29) comprised patients who had cataract surgery deferred until after the 6-month visit. Assessment included visual acuity, quality of life (QoL) and fundus fluorescein angiography (FFA).
                Of 68 eligible eyes, 60 participated and 56 completed the study. Three referred eyes (3.2%) were ineligible on the basis of a pre-existing, unsuspected occult CNV that was detected by baseline FFA. All three cases had end-stage exudative AMD in the fellow eye. Of the study eyes in the immediate surgery arm (n = 27), one (3.7%) developed CNV compared with none (0/29) in the deferred arm (chi(2); P = 1.0) at 6 months. In the operated group, there was a 2.8-line improvement in logMAR visual acuity and 2.1-fold average gain in QoL at 6 months.
                No increased short-term risk of progression of AMD to CNV in high-risk fundi following uncomplicated phacoemulsification surgery was found. A low threshold for performing preoperative imaging in patients with AMD, especially in those with exudative AMD in the fellow eye, to exclude undetected CNV is recommended. Provided there is no CNV, there are distinct benefits of cataract surgery in people with early AMD.
At this time, it is not possible to draw reliable conclusions from the available data to determine whether cataract surgery is beneficial or harmful in people with AMD. Physicians will have to make practice decisions based on best clinical judgment until controlled trials are conducted and their findings published.
It would be valuable for future research to investigate prospective RCTs comparing cataract surgery to no surgery in patients with AMD to better evaluate whether cataract surgery is beneficial or harmful in this group. However ethical considerations need to be addressed when delaying a potentially beneficial treatment and it may not be feasible to conduct a long-term study where surgery is withheld from the control group. Utilization of pre-existing, standardized systems for grading cataract and AMD and measuring outcomes (visual acuity, change in visual acuity, worsening of AMD and quality of life measures) should be encouraged.