Three-dimensional optical coherence tomography for evaluating the retinal architecture before and after surgery for vitreomacular traction.

Abstract

PURPOSE: To investigate the morphology of the vitreoretinal interface before and after delamination of epiretinal membranes using three-dimensional volumetric high-resolution optical coherence tomography (HROCT). METHODS: Extension and intensity of vitreomacular traction due to epiretinal membranes (ERM) and the architecture of retinal layers in 14 eyes of 14 patients were evaluated preoperatively using high-resolution raster scanning OCT (Cirrus prototype, resulting in a 6x6-mm field, 2 mm in depth). Additionally, stratus OCT, visual acuity testing, and fundus photography were performed. Standardized prospective follow-up was done continuously at 1, 4, and 7 days and 1 and 3 months postoperatively. RESULTS: The ERM appeared tightly adherent to the retinal surface in 85% of cases, but nevertheless could be differentiated from the retinal surface in 100%. Vertical traction forces from the ERM to the intraretinal layers were found in 93% of cases. Structural alteration of the retina was seen neither immediately following surgery nor during follow-up. After a mean of 4 weeks, the retinal structural integrity had recovered with resolution of the traction-induced deviations seen preoperatively. Mean preoperative visual acuity increased from 0.4+/-0.2 Snellen preoperatively to 0.5+/-0.2 Snellen after 3 months. Mean retinal thickness decreased from 482+/-84 mum to 328+/-80 mum after 3 months (HROCT). CONCLUSIONS: Three-dimensional HROCT imaging enables unprecedented in vivo identification of the extension and dynamics of epiretinal traction. Epiretinal membranes are clearly delineated in the en face view, and the distribution of traction forces throughout the intraretinal layers is identified down to the level of the retinal pigment epithelium. During follow-up, quantification of substantial release in retinal traction was possible and correlated to conventional OCT findings.