Objective: To evaluate baseline characteristics, intraoperative choices, and surgical outcomes in patients operated by a vitreoretinal (VR) fellow during his first 2 years of fellowship in the Swiss medical system.

Methods: Longitudinal, monocentric, retrospective study, conducted at the University Hospitals of Geneva. Methods: All consecutive cases were included that were operated by the same VR fellow at a tertiary university centre between January 2022 and March 2024. The primary outcome was the surgical success after any surgery. Secondary outcomes were the final best-corrected visual acuity (BCVA) at the final follow-up visit as well as adverse events (AEs).

Results: One-hundred eyes of 89 patients were included (65 men and 24 women, mean age 61.5 ± 16.1 years, range 22 - 94 years). Out of those 100 vitrectomies, 38.0% were operated by the fellow with the supervisor, who was present in the operating theatre but not sitting at the microscope (group A), 36.0% were operated under direct observation by the supervisor who was sitting at the microscope next to the fellow (group B), and in 26.0% of the eyes with the fellow able to do perform only some parts of the surgery based on his expertise at that time, while the rest was completed by the supervisor (group C). The main type of surgery performed was vitrectomy for rhegmatogenous retinal detachment (52.0%; n = 52) followed by silicone oil removal (13.0%), endophthalmitis (8.0%), epiretinal membrane peeling (8.0%), secondary intraocular lens (7.0%), trauma (5.0%), diabetic haemorrhage or tractional retinal detachment (4.0%), macular hole (2.0%), and vitreous haemorrhage (1%). Out of all these, 58.0% of the operations were classified as emergency (mostly rhegmatogenous retinal detachment (RRD), endophthalmitis and trauma), and 42.0% as elective. Eighty-three operations were standalone vitrectomies, while 17 were combined with cataract surgery. In the group undergoing vitrectomy for RRD, the most frequent operation performed, 48.1% of the operations belong to group A, while the rest was split between groups B and C. Forty eyes (79.6%) were classified as recent and uncomplicated RRD, and 12 (23.1%) as long-standing or complicated RRD. Most of the RRD cases were macula-on (59.6%; n = 31) and phakic (69.2%; n = 36). In order to manage RRD, perfluorocarbon liquid was used in 40.4% of the eyes, and retinotomy was performed in 26.9% of the cases. Thirty-four patients (65.4%) required a 360° laser retinopexy and ab-externo cryocoagulation of the retinal tears. The most often used endotamponade for RRD surgery was 14% C3F8 gas (42.3%; n = 22) followed by 20% SF6 gas (26.9%; n = 14), heavy silicone oil (13.5%; n = 7); 1000 cSt silicone oil (9.7%; n = 5), and 5000 cSt silicone oil (3.9%; n = 2). Out of all operations, mean BCVA improved significantly during follow-up (0.32 ± 0.34 decimals at baseline vs. 0.47 ± 0.30 decimals at the final follow-up; p < 0.05). Four eyes (4.0%) were classified as failures and required a subsequent operation, mostly for recurrent RRD. The most frequent AE was post-operative cystoid macular oedema, which occurred in 4.0% of the eyes, and cataract development, which occurred in almost all patients who were phakic at the time of surgery. One patient experienced a lens touch during the surgery for RRD and had developed a white cataract at post-operative follow-up. Average follow-up time was 5.5 ± 5.4 months (range 1 - 24 months).

Conclusions: This study provides a comprehensive analysis of the surgical outcomes and intraoperative experiences of a vitreoretinal fellow during their initial 2-year fellowship in Switzerland. The majority of operations, notably for rhegmatogenous retinal detachment, gave successful outcomes with significant improvements in visual acuity observed post-operatively. The collaborative approach between the fellow and the supervisors varying from direct observation to independent performance showcases a structured training environment. Despite encountering some adverse events, our findings underscore the effectiveness of the fellowship programme in imparting valuable surgical skills and achieving favourable patient outcomes in vitreoretinal surgery.