Structure–function analysis for macular surgery in patients with coexisting glaucoma

Purpose To develop methods to assess the effects of epiretinal membranes (ERM) and macular holes (MH) coexisting with glaucoma on pre-operative retinal structure and function and evaluate post-operative outcomes. Methods Seven eyes of 7 patients with glaucoma, 6 with ERMs and 1 with MH, were enrolled; 4 underwent vitrectomy for ERM and one for MH. Visual fields (VFs) and optical coherence tomography (OCT) scans were obtained pre- and post-operatively. The 10-2VF deviation map was overlayed on ganglion cell and inner plexiform layer (GCL + IPL) and retinal nerve fiber layer (RNFL) deviation maps derived from OCT macula and disc cube scans. Optic nerve circle scans were obtained to assess RNFL thickness, and OCT b-scans associated with VF defects were compared pre- and post-operatively. Results Examination of pre-operative VFs and OCT scans showed the importance of determining the extent to which glaucomatous damage contributed to VF loss; verifying automated segmentation of the GCL + IPL and RNFL; and assessing foveal anatomy. Evaluation of post-operative structure–function outcomes required correction of magnification changes in OCT scans and repeated follow-up visits to clarify the origin of VF changes. Conclusions Pre-operative comparisons of VFs and OCT scans may be beneficial in guiding surgical planning, and evaluating outcomes, in eyes with glaucoma undergoing macular surgery.