Purpose To investigate the relationship between proliferative diabetic retinopathy (PDR) and ocular hemodynamics by measuring ophthalmodynamometric pressure (ODP) during pars plana vitrectomy (PPV) and compare the results with non-diabetic, non-vascular vitreoretinal disorders. Methods This cross-sectional study included 53 patients who underwent PPV under general anesthesia by a single surgeon. One group included 18 individuals with PDR, while the other group included 35 non-diabetic patients with conditions such as rhegmatogenous retinal detachment, macular hole, or epiretinal membrane. We used a vented-gas forced-infusion (VGFI) system to measure ODP during the operation. Systemic diastolic blood pressure (DBP), systolic blood pressure (SBP), and mean arterial pressure (MAP) were measured simultaneously. Linear mixed-effect models (LMMs) were employed to compare adjusted ODP values. Results The median age of PDR cases and non-vascular vitreoretinal cases was 65.0 and 64.0 years, respectively, without a significant difference. The mean ODP in the PDR group was 47.8 mmHg (95%CI: 44.3–51.3), and the corresponding value in the non-diabetic cases was 46.9 mmHg (95%CI: 43.7–50.0), without any significant difference ( p = 0.713). The adjusted ODP values for DBP, SBP, and MAP also showed no significant difference between the groups. The DBP and MAP were substantial predictors of ODP (βs: 0.676 and 0.278, respectively). Conclusion ODP values may not differ in PDR cases compared with other non-vascular indications of PPV. The DBP is the most crucial predictor of ODP, followed by MAP. The DBP should be more closely monitored during the intraoperative period to decrease the risk of retinal ischemic events during PPV due to excessively reduced ODP.
Milani et al. (Mon,) studied this question.