Comparison of UHR-OCT versus Stratus-OCT for definition of early retinal changes after intravitreal Bevacizumab (Avastin®) application in patients with AMD

Abstract

PURPOSE: To investigate and demonstrate early structural changes of the retina/pigmentepithelial/choriocapillaris (RPECC) complex before and 10 ± 3 days after intravitreal application of bevacizumab (Avastin®) in patients with neovascular age related macular degeneration (nAMD) by comparison of standard Stratus Optical Coherence Tomography (S-OCT) and Ultra High Resolution (UHR-OCT) imaging systems. METHODS: Six patients with nAMD were examined in a consecutive case series with UHR-OCT and Stratus OCT one day before and 10 ± 3 days after intravitreal application of 1.25 mg (0.125 ml) bevacizumab (Avastin®). Maximum central retinal thickness (CRT) was measured with the retinal thickness program and calliper measuring function of S-OCT and by the measuring tool of Adobe Photoshop 5.0 in UHR-OCT pictures. RESULTS: In three of six cases residual fluid after treatment was only visible with UHR-OCT but not with the S-OCT. A decrease of maximum CRT could be shown in all cases in UHR-OCT pictures but only in half of the cases (6/3) in S-OCT pictures. In 2/6 cases vitreoretinal adhesions were demonstrable with UHR-OCT but not seen with the S-OCT, irregularities in the photoreceptor layer could be revealed clearly by UHR-OCT in 2/6 cases. CONCLUSION: After anti-VEGF treatment, UHR–OCT gives more accurate information about residual fluid and intraretinal damage than S-OCT and offers more precise measurements of maximum CRT. These factors may influence further decision of therapy and give us a better explanation and correlation with unsatisfactory visual acuities than with the S-OCT.