Visual function following photodynamic therapy for central serous chorioretinopathy: a comparison of automated macular microperimetry versus best-corrected visual acuity

Background: The study compares the change in best-corrected visual acuity with the change in central retinal sensitivity before treatment and 6 months after treatment with photodynamic therapy in patients with symptomatic central serous chorio retinopathy. Design: Prospective, single-centre, interventional case series. Participants: Eleven consecutive patients with previously untreated central serous chorio retinopathy. Methods: Patients had microperimetry and best-corrected visual acuity recorded before and 6 months after treatment with photodynamic therapy. Refracted best-corrected visual acuity was assessed at 2 m and adjusted to give the number of letters read at 1 m. Threshold microperimetry was performed by presenting a Goldman III stimulus to 29 points over the central 12 around fixation. Significant visual improvement at 6 months was defined as a best-corrected visual acuity >= 10 letters or, microperimetry change in mean retinal sensitivity >= 2 decibels (dB). Main Outcome Measures: Improvement in best-corrected visual acuity compared with microperimetry following photodynamic therapy treatment in patients with central serous chorio retinopathy. Results: All patients reported a subjective improvement in vision and had complete resolution of subretinal fluid at 6 months. Two patients had a significant improvement in best-corrected visual acuity (mean +/- SD +4.2 +/- 5.8 letters), compared with all 11 patients who recorded a significant improvement in mean retinal sensitivity (mean +/- SD 4.6 +/- 1.9 dB) (P < 0.001). Conclusions: These data suggest that compared with microperimetry, best-corrected visual acuity is underestimating the effectiveness of photodynamic therapy in the treatment of central serous chorio retinopathy.