Observation on long-term efficacy of half-dose photodynamic therapy with chronic central serous chorioretinopathy using optical coherence tomography

Abstract

To evaluate long-term efficacy of half-dose photodynamic therapy on chronic central serous chorioretinopathy using optical coherence tomography. A retrospective, interventional case series. Thirty-five eyes of 32 patients (35 eyes) with chronic central serous chorioretinopathy were included, with CSC durations from 6 to 60 months. Patients treated with half-dose verteporfin (3 mg/m(2)) PDT were followed up for 24 months. Best-corrected visual acuity (BCVA), fluorescein angiography (FA), indocyanine green angiography (ICGA) and optical coherence tomography (OCT) pre and post-treatment were all examined to observe the anatomic and functional changes. OCT findings highlighted the alterations of the ellipsoid zone (EZ), the interdigitation zone (IZ) and the central neural retina thickness (CNT) from 3 month to 24 month post-treatment. Regression analysis was applied to determine the correlation between the visual function (BCVA) and structure status (EZ, IZ, CNT). Thirty-five eyes of 32 patients with chronic CSC were treated with half-dose PDT. The logMAR BCVA was 0.53±0.36 at baseline, 0.49±0.39 at 3 months and 0.15±0.38 at 24 months post-PDT. There was no statistical significance between baseline and 3 month BCVA (t=1.952, P>0.05). There existed statistical significance between baseline and 24 month BCVA(t=10.761, P<0.01) as well as 3month and 24 month BCVA(t=8.930, P<0.01). OCT demonstrated the recovery of EZ and IZ. Statistical differences of EZ and IZ integrity degree were found between the 3 month and 24 month (Z=-3.419, -4.082, P<0.01). The mean CNT was (126.8±34.9) μm at baseline. And it kept constant at 3 month [(125.6±34.3)μm] and the 24 month visit [(124.8±35.1)μm]. No statistical significance was found between any two values (t=-1.830, -1.569, 0.793, P>0.05). At baseline, 3 month and 24 month, there was negative correlation between logMAR BCVA and CNT (β=-0.604, -0.634, -0.685, P<0.01) . At 3 month and 24 month, negative correlation between logMAR BCVA and EZ as well as logMAR BCVA and IZ were also found(β=-0.376, -0.394, -0.628, -0.496, P<0.05). A complete resolution of subretinal fluid was noted in 94.3% eyes at 3 month, further increased to 100% eyes at 24 month. The mean session of PDT was 1.03±0.17. Half-dose PDT was safe and effective for chronic CSC both functionally and morphologically in the long term. Visual benefits may not appear in a short run, yet became remarkable in a long run. Visual benefits might be attributed to recovery of EZ and IZ.