Impact of Topographic Hot Spots on the Refractive Outcomes of Combined DMEK and Cataract Surgery

Purpose: To compare the refractive results of combined Descemet membrane endothelial keratoplasty (DMEK) and cataract surgery in eyes with Fuchs endothelial corneal dystrophy (FECD) with and without topographic hot spots. Setting: "Villa Igea" Hospital, Forlì, Italy. Design: Interventional case series. Methods: In this single-center study, 57 eyes of 52 patients with FECD undergoing combined DMEK, cataract surgery and monofocal intraocular lens (IOL) implantation were included. Patients were classified based on the presence or absence of topographic hot spots on the preoperative axial power map. Prediction error (PE) was calculated as the postoperative manifest spherical equivalent (SE) refraction minus the SE predicted refraction. Results: Six months after surgery, mean PE was +0.79 ± 1.12 D. In eyes with hot spots, mean K, K flat and K steep significantly decreased after surgery (all P < 0.05), while no significant changes were observed in eyes without hot spots (all P > 0.05). Eyes with hot spots showed a significantly more hyperopic PE than eyes without hot spots (+1.13 ± 1.23 vs +0.40 ± 0.86 D; P = 0.013). Conclusion: Combined DMEK and cataract surgery can result in a hyperopic refractive surprise. The presence of topographic hot spots before surgery is associated with a higher hyperopic shift.