Combined phacoemulsification surgery and intravitreal triamcinolone injection versus stand-alone surgery in patients with type 2 diabetes: a prospective randomized trial

BACKGROUND: We would assess the efficacy of intravitreal injection of triamcinolone acetonide IVTA combined with standard phacoemulsification on the central subfield macular thickness (CSMT), the progression of diabetic retinopathy (DR), and the corrected distant visual acuity (CDVA) in type 2 diabetic patients. METHODS: In this prospective single-blinded randomized clinical trial we recruited patients with type 2 diabetes who were eligible for cataract surgery. The patients were randomly assigned to two groups. The case group received an intravitreal IVTA at the end of phacoemulsification, and the control group had routine surgery. CSMT, progression of DR, CDVA, IOP, and adverse events including endophthalmitis were compared between the groups preoperatively and at 1, 3, and 6 months postoperatively. RESULTS: Among a total of 66 patients that were treated within the study period, 50 patients were included in the final analysis. The case group comprised 21 eyes, and the control group included 29 eyes. Regression models and corrected ANOVA test for repeated measures showed a significant reduction in CSMT at 3 and 6 months postoperatively, which was most significant when the preoperative CSMT was ≥300 μm, with a cut-off value of 347.3 μm in the case group (p < 0.000). DR progression was halted in the case group at 6 months with 52.38% of patients having their DR classified as moderate (P = 0.012). CDVA was significantly improved from baseline 6/60 (logMAR 1.0) pre-op to 6/6 (logMAR 0.00) at 6 months post-op in the case group, and from baseline 6/120 (logMAR 1.3) pre-op to 6/12 (logMAR 0.3) at 6 months post-op in the control group. The gain in visual acuity was significantly higher in the case group at all study points (p < 0.001). No significant rise in IOP was observed at any study point in both groups (p = 0.23 > 0.05). No endophthalmitis was recorded. CONCLUSIONS: Diabetic patients benefit significantly from cataract surgery. This study supports IVTA injection at the end of phacoemulsification in diabetic patients. Triamcinolone is an affordable (which is of particular importance in low-income countries as per our setting), and relatively safe “phaco-enhancer”. TRIAL REGISTRATION: NCT05413330. Initial release 10/06/2022. Unique Protocol ID: UDMS-Opthal-01-2022.