Small laser spot versus standard laser spot photodynamic therapy for idiopathic choroidal neovascularization: a randomized controlled study

Background Idiopathic choroidal neovascularization (ICNV) affects young patients and thus may have a significant impact on vision and life quality over a patient's lifespan. This study was designed to compare the visual outcome and retinal pigment epithelium (RPE) damage after photodynamic therapy (PDT) with small laser spot and PDT with standard laser spot for idiopathic choroidal neovascularization (ICNV). Methods This was a randomized controlled study. Fifty-two patients with ICNV were enrolled and randomly divided into a study group (small laser spot PDT, n=27) and a control group (standard laser spot PDT, n=25). Best corrected visual acuity (BCVA), optic coherence tomography (OCT) and fluorescein angiography (FA) findings were the main measurements. The patients were followed up 1 week, 1, 3, 6, 9 months and 1 year after PDT. Results BCVA improvement was statistically significantly higher in the study group than the control group at 6-month ((25.53 +/- 15.01) letters vs. (14.71 +/- 11.66) letters, P=0.025) and 9-month follow-ups ((27.53 +/- 17.78) letters vs. (15.59 +/- 12.21) letters, P=0.039). At 3- and 6-month follow-ups, the quadrants of RPE damage between the two groups varied significantly (P <0.001 and P=0.023, respectively). In each follow-up, the number of cases with decreased or unchanged leakage of choroidal neovascularization by FA and reduced subretinal fluid by OCT did not vary significantly between the two groups. Ten cases (37.0%) in the study group and eight cases (32.0%) in the control group suffered from recurrent CNV (P=0.703). Conclusions Better visual improvements, less RPE damage, a similar recurrent rate of CNV and change of subretinal fluid were observed in the small laser spot PDT group than in the standard laser spot PDT group for ICNV. Chin Med J 2012;125(24):4424-4428