Long-Term Effect of Half-Fluence Photodynamic Therapy on Fundus Autofluorescence in Acute Central Serous Chorioretinopathy

Abstract

Purpose: To evaluate normalized short-wavelength fundus autofluorescence (SW-FAF) imaging changes over time as a predictive parameter for the retinal pigment epithelium (RPE) function in eyes compromised by acute central serous chorioretinopathy (CSCR) after indocyanine green angiography-guided verteporfin (Visudyne®, Novartis Pharma, Basel, Switzerland) photodynamic therapy (PDT) with a half-fluence rate (25 J/cm²).

Methods: Quantitative data of SW-FAF grey values (SW-FAF GV) from a 350 μm (SW-350) and 1200 μm (SW-350) and 1200 t-test was calculated to explore the differences of SW-350 and SW-1200 between one month and the long-term follow-up.

Results: Mean differences (95% CI) in SW-FAF GV between 1 month and 7 years after half-fluence PDT were 0.07 ± 0.11 for SW-350 ([95% CI: -0.002; 0.14], p=0.06) and 0.11 ± 0.15 for SW-1200 ([95% CI: 0.01; 0.21], p=0.06) and 0.11 ± 0.15 for SW-1200 ([95% CI: 0.01; 0.21], p=0.06) and 0.11 ± 0.15 for SW-1200 ([95% CI: 0.01; 0.21], p=0.06) and 0.11 ± 0.15 for SW-1200 ([95% CI: 0.01; 0.21].

Conclusion: After 7 years, normalized SW-FAF GV were significantly lower in eyes with resolved acute CSCR treated with reduced-fluence PDT compared to the follow-up after 1 month without correlation to explicit pattern changes or structural damages. Half-fluence PDT remains a safe and considerable treatment option in acute CSCR.

Figure 1

Diagnostic and therapeutic protocol of a left eye with acute CSCR. (a) Late fluorescence angiography with juxta foveal late leakage and a smokestack sign. Below, a spectral domain optical coherence tomography (SD-OCT) slab with subfoveal fluid accumulation corresponding to the bar in the en face image. (b) Midphase indocyanine green angiography showing a 1500 μm laser spot centered at the hyperpermeability. SD-OCT segment through the treatment area with flat pigment epithelial detachment (PED) (arrow). (c) Fundus autofluorescence (FAF) of the same lesion 1 month after treatment with a ring of hyperfluorescence (arrows) demarcating the borders of subretinal fluid extension and two measurement rings encircling the fovea in a 350 μm (SW-350) and 1200 μm (SW-1200) diameter. The short-wavelength (SW) FAF grey values (GV) of both encircled areas were normalized by dividing them through the SW-FAF GV of the complete picture. Resolution of subretinal fluid is visible on the SD-OCT B-scan. (d) The same eye 77 months after treatment with both measurement rings encircling homogenous FAF demonstrating minor hypofluorescent remnants nasal to the fovea (arrow) corresponding to a hyperreflective PED in SD-OCT.

Figure 2

Distribution of normalized short-wavelength fundus autofluorescence grey values (SW-FAF GV). (a) Differences of SW-FAF GV for a 350 μm (SW-350) diameter circle centered at the fovea 1 month vs. 83 months after half-fluence photodynamic therapy (PDT). (b) Differences of SW-FAF GV for a 1200 μm (SW-1200) diameter circle centered at the fovea 1 month vs. 83 months after half-fluence PDT. (c) Differences of SW-350 of the contralateral eye 1 month vs. 83 months. (d) Differences of SW-1200 of the contralateral eye 1 month vs. 83 months.