Bariatric Surgery Impacts Retinal Vessel Status Assessed by Optical Coherence Tomography Angiography: A Prospective 12 Months Study

<b>Objectives:</b> To assess retinal microvascular changes in patients with Grade II and III obesity before and after bariatric surgery using Optical Coherence Tomography Angiography (OCTA), and to compare these metrics with age- and sex-matched healthy controls. <b>Methods:</b> Prospective, consecutive, longitudinal cohort study with a 12-month follow-up. Grade II and III obese patients scheduled for bariatric surgery underwent comprehensive ophthalmic examinations, including OCTA imaging, prior to the surgery and postoperatively at 1 month, 6 months, and 12 months post-surgery. <b>Results:</b> A total of 43 eyes from 43 patients with obesity (one eye per patient) were included at baseline. At 12 months post-surgery, there was a significant increase in vessel density (VD) (16.70 vs. 17.68; <i>p</i> < 0.01) and perfusion density (PD) (0.406 vs. 0.433; <i>p</i> < 0.01), reaching values comparable to those of the control group (17.73 and 0.434, respectively). Significant reductions were also observed in body mass index (BMI) (43.74 vs. 29.53; <i>p</i> < 0.01), body weight (122.44 kg vs. 81.90 kg; <i>p</i> < 0.01), and intraocular pressure (IOP) (15.72 mmHg vs. 14.16 mmHg; <i>p</i> < 0.01). <b>Conclusions:</b> This study demonstrates a compelling association between obesity and retinal microvascular impairment, highlighting the efficacy of bariatric surgery not only in achieving substantial weight loss but also in improving the retinal perfusion of these patients, achieving metrics at 12 months comparable to age- and sex-matched healthy controls at baseline. These findings raise the hypothesis of the potential utility of OCTA as a monitoring tool for tracking the microvascular status in patients with obesity undergoing bariatric surgery in a longitudinal manner.