High-resolution optical coherence tomography to evaluate vitreomacular traction before and after membrane peeling

Aim. Morphological assessment of the vitreomacular interface and intraretinal architecture using three-dimensional high-resolution optical coherence tomography (HROCT) before and after surgical delamination of epiretinal membranes and the internal limiting membrane (ILM). Method. The extent and intensity of traction of the epiretinal membrane (ERM) and the morphology of the individual retinal layers were investigated preoperatively in 14 eyes of 14 patients using three-dimensional HROCT (Cirrus prototype, scanned area 6x6 mm, depth 2 mm). In addition, visual acuity and ophthalmological findings (including stratus OCT) were documented. Standardized follow-up examinations were performed prospectively adhering to a protocol on days 1, 4, and 7 as well as 1 and 3 months after surgery. Results. The ERM adhered closely to the retina in 85% of cases, but in 100% it was still clearly distinguishable from the retinal surface as a separate structure when using HROCT. Vertical traction through the ERM to the deepest retinal layers could be shown on HROCT in 93% of the cases. Structural alterations of the retina were not detectable either directly after surgery or subsequently. After an average of 4 weeks, the architecture of the layers was reorganized with complete regression of the preoperative tractional aberrations. The mean preoperative Snellen visual acuity of 0.4 +/- 0.2 increased to an average of 0.5 +/- 0.2. The mean preoperative retinal thickness was 482 +/- 84 mu m and after 3 months 328 +/- 80 mu m (HROCT). Conclusions. Examination with high-resolution optical coherence tomography allows three-dimensional visualization of the dynamics of epiretinal tractions that had not previously been obtainable. Epiretinal membranes can be clearly distinguished and their tractional effects can be traced through all retinal layers up to the pigment epithelium. As a result of the postoperative elimination of the tractions, the morphological alterations of the individual retinal layers recede already after 1 month.