OCT–Findings in patients treated with Selective–RPE–Laser–Treatment (SRT)

Abstract

Abstract: : Purpose: Selective–RPE–laser–treatment (SRT) is currently investigated in a clinical multicenter trial for patients with diabetic maculopathy (DMP), branch retinal vein occlusion (BRVO), central serous retinopathy (CSR) and age–related–macular degeneration associated with geographic atrophy (GA) and okkult choroidal neovaskularisation (occCNV). SRT uses a train of short laser pulses and selektively damages RPE cells while sparing retinal structures. Methods: 11 eyes of 11 patients (3 with DMP, 3 with BRVO, 3 CSR, 2 AMD) were enrolled to the study at the center Kiel so far. After having passed screening visits with documentation of standardized visual acuity (VA), fluorescein angiography (FA) and OCT (OCT III, Humphrey/Zeiss) the patients were treated with SRT using a frequency doubled Q–switched Nd:YLF laser (527 nm). Each laser exposition applies a train of 30 pulses, each of 1.7 µs duration, at a repetition rate of 100 Hz. Control–visits were perfomed 3 and 6 months (BRVO, DMP) or 1, 3, 6 months (GA, okkCNV) after treatment with the same investigations done at the screening visit. Total volume was calculated within an area of 6 mm around the fovea. Results: All patients have passed the 3 months follow–up visit. Absolute retinal thickness decreased in DMP by 46 µm, in BVO by 167 µm and in CSR by 115 µm. In Patients with GA and occCNV no obvious changes could be dokumented. Retinal thickness measured by calculation of the total retinal volume in a macula–area of 6mm diameter was reduced in patients with DMP by 5.2%, in BRVO–patients by 17.1% and in CSR by 12,5 % on average. Conclusion: SRT laser treatment shows a short term effect in reducing retinal thickness in patients with DMP and BRVO. OCT III with retinal map analysis is a sufficient method to detect retinal thickness–changes after the treatment. Further documentation and long term observation of the treated patients is needed to verify the promising short term results.

Keywords: laser • macula/fovea • retinal pigment epithelium