Correlation of Integrity of Cone Outer Segment Tips Line With Retinal Sensitivity After Half-dose Photodynamic Therapy for Chronic Central Serous Chorioretinopathy

Abstract

To investigate the relationship between the integrity of the photoreceptor microstructures and retinal sensitivity after half-dose photodynamic therapy (PDT) in eyes with chronic central serous chorioretinopathy (CSC). Prospective, noncomparative, interventional case series. Thirteen eyes of 13 patients with chronic CSC who had received half-dose verteporfin PDT were studied. The best-corrected visual acuity (BCVA), macular retinal sensitivity in the central 12 degrees, and optical coherence tomographic (OCT) findings were evaluated at baseline and at 1, 3, 6, and 12 months after the half-dose PDT. The integrities of the external limiting membrane (ELM), the inner segment/outer segment junction (IS/OS) line, and the cone outer segment tips (COST) line were determined. The retinal sensitivity was determined by MP-1 microperimetry. The serous retinal detachment (SRD) was completely resolved in 11 eyes at 1 month and in 1 eye at 3 months. The remaining eye had a persistent SRD throughout the follow-up period. The mean retinal sensitivity was significantly better at 1, 3, 6, and 12 months after the half-dose PDT than at baseline. Before the PDT, 12 eyes had a continuous ELM and 1 eye had a fragmented ELM. The number of eyes with an intact IS/OS line and COST line increased with increasing post-PDT time. At 12 months after PDT, the IS/OS line was detected in 11 eyes and the COST line in 6 eyes. At 6 and 12 months, the retinal sensitivity was significantly higher in eyes with an intact COST line and IS/OS lines than in eyes with an intact IS/OS line only. However, no difference was found in the visual acuity of these 2 groups. The 1 eye with a persistent SRD and another eye with fragmented ELM and absent IS/OS and COST lines through the follow-up periods were associated with poor retinal sensitivity of 8.5 dB and 10.9 dB respectively. Our findings show that there is a significant improvement in the macular sensitivity after half-dose PDT in eyes with chronic CSC. The improvement was correlated with the recovery of the IS/OS and COST lines at 6 and 12 months.