Abstract
Purpose::
To document treatment effects of intravitreal bevacizumab in patients with neovascular age-related macular degeneration (AMD) using Stratus® optical coherence tomography (OCT) and high definition, spectral-domain optical coherence tomography (HD-OCT).
Methods::
14 eyes of 14 patients (mean age 76 years) with choroidal neovascuarization were treated with three initial intravitreal bevacizumab injections at four-week intervals. Follow-up evaluation included visual acuity using ETDRS charts and 1mm central retinal thickness (CRT) using Stratus® OCT. Additionally, examination with a HD-OCT instrument based on spectral domain technology provided by Carl Zeiss Meditec Inc. was performed. A volume of 5.8mm x 5.8mm x 2mm was scanned via raster scan technique with an axial resolution of 5µm. Retreatment was based on change in visual acuity and retinal thickness in Stratus® OCT.
Results::
Stratus® OCT demonstrated a rapid reduction of CRT. At month three CRT was significantly reduced by 126µm. Accordingly, mean retinal thickness and total retinal volume as measured by HD-OCT decreased from 343µm/12.1µm³ at baseline to 269µm/9.7µm³ at month three. In addition, HD-OCT allowed improved visualization of all central retinal changes following anti-VEGF therapy, improved reliability of the algorithm for CRT measurements even in eyes with significant pathologic retinal changes, and new segmentation abilities. Segmentation of the RPE showed regression of pigment epithelial detachments following intravitreal bevacizumab within three months follow-up
Conclusions::
Stratus® and HD-OCT are most valuable tools in evaluating treatment response to intravitreal anti-VEGF therapy. Major advantages of the new HD-OCT are the rapid imaging of a three-dimensional retinal sample, improved automated calculation of retinal thickness and volume as well as new segmentation modalities allowing better understanding of therapeutic effects of anti-VEGF therapy.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • age-related macular degeneration • choroid: neovascularization