Abstract
Purpose: :
Using spectral domain optical coherence tomography (SD-OCT) and microperimetry to document structural and functional retinal changes after antiagiogenic therapy (Bevacizumab,Avastin®) in patients with macular edema secondary to retinal vein occlusion (RVO).
Methods: :
This prospective non-controlled study (EUDRACT NR-2005-003288-21), enrolled patients (N = 29) with macula edema due to central or branch retinal vein occlusion. All patients initially received three intravitreal injections of 1 mg bevacizumab at 4 week intervals.Retreatment was based on OCT results. During monthly follow-up, a SD OCT instrument (Cirrus, Carl Zeiss Meditec AG) was used to assess detailed images via raster scan technique with an axial resolution of 5 µm of a 20°x20° area. Carl Zeiss Meditec Research Browser software (V.2.0.0.62) was used to calculate retinal volume within the scanned area. To document changes of retinal function, visual acuity (VA) and microperimetry (Nidek, MP1 Microperimeter) were assessed.
Results: :
Three antiangiogenic injections induced a reduction of central retinal thickness (CRT) of a mean of 218µm (p = 0.01, N = 9) as documented by SD-OCT. Accordingly the calculated sub-center retinal volume decreased about mean 1.5mm3 (p = 0.2, N = 9). In good accordance VA showed an improvement of mean 10 letters on ETDRS chart and, as assessed with microperimetry, mean absolute scotoma of 7 missed stimulation points out of 41 at baseline decreased to 3 missed stimulation points out of 41 after 3 month. Due to recurrent edema after 6 month, mean CRT re-thickened (+171µm) and sub- center retinal volume increased again (+ 2mm3) as compared to the 3 month results. Despite recurrent edema median VA remained stable, as well as the area of absolute scotoma within the central visual field. The correlation between the changes of retinal volume and the change in area of absolute scotoma was however, not significant.
Conclusions: :
HD-OCT and microperimetry are exellent tools in documenting retinal morphology and function, allowing better understanding of therapeutic effects on the retina.
Clinical Trial: :
EUDRACT NR-2005-003288-21
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • edema