Relationship between Image Quality and Reproducibility of Surgical Images in 3D Digital Surgery

Objectives: Ophthalmic three-dimensional (3D) digital surgery can reproduce high-definition surgical images; however, 3D digital surgery is limited by recording capacities. We examined the relationship between the minimum image quality required to reproduce surgical images and recording capacity. Methods: Patients who underwent simultaneous vitrectomy and cataract surgery by the same surgeon using a 3D digital surgery system at Juntendo University Urayasu Hospital between February and October 2021 were evaluated. Various quality (Q) and frame rate (FR) settings were used for each case. Four vitreous surgeons evaluated the reproducibility of recorded images of macular manipulation for epiretinal membrane (ERM) and macular hole (MH) cases and those of peripheral retinal manipulation for rhegmatogenous retinal detachment (RRD) cases. The video bitrate and minimum settings required to reproduce surgical images and factors affecting surgical image reproducibility were examined. Results: A total of 129 eyes of 129 patients were observed. The minimum image quality required to reproduce surgical images was 11.67 Mbps. The Q and FR for periretinal processing and Q for macular manipulation affected surgical image reproducibility (p = 0.025, p = 0.019, and p = 0.07, respectively). The minimum recording settings required to obtain highly reproducible images were Q = 3 and FR = 40. The total file size for vitrectomy video recordings with these settings was as compact as 3.17 GB for 28 min. Conclusions: During 3D digital surgery, highly reproducible surgical images can be obtained with a small storage capacity using settings of at least Q = 3 and FR = 40.