Blue-light versus green-light autofluorescence: lesion size of areas of geographic atrophy.

PURPOSE: Blue-light fundus autofluorescence (FAF) imaging is currently widely used for assessing dry age-related macular degeneration (ARMD). However, at this wavelength, the fovea appears as circular zone of marked hypofluorescence, due to the absorption of macular pigment (MP). This dark spot could be misinterpreted as an atrophic area and could lead to difficulties in identifying small, central changes. The purpose of the study was to analyze differences in image quality, FAF patterns, and lesion size, when using conventional blue-light (Λ(1) = 488 nm) and green-light (Λ(2) = 514 nm) FAF. METHODS: Patients older than 50 years with central areas of geographic atrophy (GA) secondary to ARMD were enrolled. Images were recorded with a modified confocal scanning laser ophthalmoscope (cSLO). Image quality and patterns were analyzed. The quantification of the GA was performed with customized image-analysis software. RESULTS: In total, 95 eyes were included. The borders of the central atrophic patches and the boundaries of the preserved foveal island were better identified in 514-nm images. In both excitation wavelengths the signal-to-noise ratio was sufficient for the identification of the FAF pattern. Significant differences were observed in the size of the GA areas detected in the 488- and 514-nm wavelength images (4.29 ± 3.76 mm(2) vs. 3.80 ± 3.68 mm(2); P < 0.001). CONCLUSIONS: The green-light FAF images (514 nm) are superior for the accurate analysis of small, central, pathologic changes, and for the determination of the central GA lesion size. Using only blue-light FAF could lead to an overinterpretation of the size of atrophic patches and the center involvement, because it suggests the presence of atrophy in the fovea.

Predictors of short-term visual outcome after anti-VEGF therapy of macular edema due to central retinal vein occlusion.

PURPOSE: The purpose of this study was to analyze predictive factors for best-corrected visual acuity (BCVA) after anti-VEGF treatment in patients with macular edema (ME) secondary to central retinal vein occlusion (CRVO). METHODS: This prospective study enrolled treatment-naive patients with ME secondary to CRVO. BCVA, ophthalmoscopy, fundus photography, and spectral domain optical coherence tomography (SD-OCT) imaging were performed. SD-OCT was analyzed for integrity of the external limiting membrane (ELM), photoreceptor inner segments (IS), and outer segments (OS). Patients were treated with intravitreal bevacizumab (1.25 mg) or ranibizumab (0.5 mg). BCVA outcome was analyzed 4 weeks after the first injection. RESULTS: Sixty-two eyes of 62 patients (39 men, 23 women; mean age: 67 ±16 years) were included. In 55%, the ELM was intact. These eyes also showed intact photoreceptor IS/OS in horizontal and vertical single scans. Disturbed ELM was seen in 45% and was accompanied by focal disintegration of IS/OS. Four weeks after injection, 58% showed clinically relevant increases of BCVA (≥5 letters). Mean BCVA ranged from 20 to 86 letters. The mean BCVA increase was 18 ± 12 letters in eyes with intact ELM compared with 4 ± 10 letters with disturbed ELM (P < 0.001). CONCLUSIONS: Depending on the integrity of the outer retinal layers, the authors observed rapid and clinically relevant improvement in BCVA after the first anti-VEGF injection. In the development of an optimal treatment regime, the indication for treatment and re-treatment should be based on functional and morphologic findings, such as the deterioration of outer retinal layers. Intact ELM in SD-OCT imaging is associated with better visual outcomes after intravitreal anti-VEGF treatment in patients with ME secondary to CRVO.