Incidence of and Risk Factors for Postoperative Hyphema After 23-Gauge Pars Plana Vitrectomy for Proliferative Diabetic Retinopathy.

Purpose We aim to investigate the incidence, clinical course, and risk factors for developing postoperative hyphema after 23-gauge pars plana vitrectomy (PPV) for patients with proliferative diabetic retinopathy (PDR) without neovascularization of the iris or angles and neovascular glaucoma (NVG). Methods This retrospective study included 155 consecutive eyes from 124 patients with at least three-month follow-up who underwent PPV for PDR without neovascularization of the iris or angles and NVG. Demographic data, surgery notes, postoperative hyphema assessment, intraocular pressure (IOP), and the surgical outcome were recorded. Results Postoperative hyphema occurred in 18 of 155 eyes (11.6%), with 14 of those having hyphema on day 1, and 4 having hyphema on days 7-20. Of the 18 eyes, only 3 (16.7%) had normal IOP, and immediate intraocular hypertension was observed in 15 (83.3%). Seven eyes required anterior chamber paracentesis and five needed anterior chamber irrigation. The average time for absorption of the hyphema was 13.1 days, and IOP was controlled in all cases. There was a significant correlation between membrane removal and the development of hyphema (OR = 5.65 and 95% CI: 1.190-25.203; p = 0.013). No recurrence of hyphema was observed. In patients with hyphema, the final best corrected visual acuity (BCVA) was 1.75 ± 0.84 logMAR, which improved significantly compared to the initial BCVA of 2.20 ± 0.65 logMAR (t = 3.893; p = 0.001), and the final anatomic success rate was 100%. Conclusion The development of hyphema is not uncommon after PPV for patients with PDR without neovascularization of the iris or angles and NVG, and membrane removal is a risk factor for postoperative hyphema. The timely management of hyphema ensures that hyphema does not affect the visual recovery or the final anatomical success.