Preferential hyperacuity perimeter in assessing responsiveness to ranibizumab therapy for exudative age-related macular degeneration

Aim To investigate the ability of the preferential hyperacuity perimeter test to assess responsiveness to ranibizumab therapy for exudative age-related macular degeneration (AMD). Methods Fourteen consecutive patients with newly diagnosed choroidal neovascularisation underwent a preferential hyperacuity perimeter metamorphopsia test (main outcome measures) 1 h before (baseline) and 1 h, 1 day, 1 week and 1 month after one intravitreal injection of ranibizumab (0.05 ml/0.5 mg). Best corrected visual acuity (BCVA) and several spectral domain optical coherence tomography (OCT) parameters (secondary outcome measures) were compared with the metamorphopsia test. Results Fourteen eyes (14 patients, 78% women, mean age 83 +/- 6.2 years) were included in the analysis. The mean preferential hyperacuity perimeter metamorphopsia test score improved significantly from 20.4 +/- 35 at baseline to 9.2 +/- 23 after the single ranibizumab injection (p < 0.05). The mean reduction in central macular thickness, maximal retinal thickness at the fovea, maximal height of subretinal fluid, maximal diameter of the largest retinal cyst and maximal height of pigment epithelial detachment, as evaluated by spectral domain OCT, closely reflected the functional improvements as evaluated by preferential hyperacuity perimeter, showing a significant correlation with metamorphopsia changes (Spearman correlation 0.9, p < 0.05). Mean BCVA improved significantly from 20/80 to 20/60 (p < 0.05). A significant correlation was also found between the mean BCVA changes and the mean metamorphopsia changes (Spearman correlation 0.97, p < 0.05). The correlation coefficient between OCT measurements and preferential hyperacuity perimeter score within subjects was 0.51 (p < 0.05). Conclusion The improvement in metamorphopsia test score after intravitreal ranibizumab injection, which correlated closely with improvement in several OCT parameters, suggests that the preferential hyperacuity perimeter test may be used to monitor the response to anti-vascular endothelial growth factor (VEGF) treatment in patients with exudative AMD.