PSEUDOPHAKIC CYSTOID MACULAR OEDEMA (PCME) PREVENTION IN PATIENTS WITH NON-PROLIFERATIVE DIABETIC RETINOPATHY (NPDR)-RANDOMIZED CONTROLLED TRIAL

The purpose of this study was to compare the effect of topical bromfenac and dexamethasone on the intraocular concentration of interleukin 6 (IL-6) and on the incidence of pseudophakic cystoid macular oedema (PCME) after cataract surgery in patients with non-proliferative diabetic retinopathy (NPDR).

In this study, we hypothesised that topical bromfenac is more effective than topical dexamethasone in reducing IL-6 concentrations in the aqueous humour and in reducing the incidence of PCME in patients with NPDR. The study was randomized, double-blinded and vehicle-controlled. The study design has been adopted from a clinical trial that was conducted by our research group and it can be found on the ClinicalTrials.gov web site using registration number NCT04940338.  

Ninety eyes of patients with mild-to-moderate NPDR that underwent phacoemulsification cataract surgery were divided into three groups. Group 1 received topical bromfenac (0.9 mg/mL), Group 2 dexamethasone (1 mg/mL), and Group 3 placebo, both preoperatively and postoperatively. Additionally, all patients received combined topical steroid and antibiotic drops (dexamethasone, neomycin and polymyxin B) 3 weeks postoperatively. On the day of the surgery, aqueous humour samples (0.1-0.2 mL) were obtained and IL-6 concentrations were analysed. Central foveal subfield thickness (CFT) measured using spectral-domain optical coherence tomography (SD-OCT) was analysed preoperatively and postoperatively.

No patient developed PCME in any of the three groups for the 90 days of the study. There was no significant difference in IL-6 concentrations between groups. Postoperative CFT was significantly lower in the dexamethasone group compared to the placebo group. In addition, in the group treated with dexamethasone, there was a statistically significant positive correlation between IL-6 and CFT (Spearman’s rank correlation). No adverse events were reported during the study. 

Topical bromfenac and dexamethasone have no significant effect on intraocular IL-6 concentration in patients with NPDR. Topical bromfenac is not more effective than topical dexamethasone in reducing postoperative CFT in patients with NPDR.

Our results indicated that application of both NSAIDs and corticosteroids for PCME prevention in patients with mild-to-moderate NPDR seems to be unnecessary. Further research should explore the optimal route and dosage of corticosteroid treatment and its long-term benefits.