Pseudophakic Cystoid Macular Oedema (PCME) Prevention in Patients with Non-Proliferative Diabetic Retinopathy (NPDR)-Randomized Controlled Trial

Abstract

Background and Objectives: 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 incidence of pseudophakic cystoid macular oedema (PCME) after cataract surgery in patients with non-proliferative diabetic retinopathy (NPDR). Materials and Methods: Ninety eyes of patients with mild-to-moderate NPDR that underwent phacoemulsification cataract surgery were divided into three groups. A detailed description of the clinical study protocol is described later in paper. In short, 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. Results: 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, the correlation between IL-6 and CFT was statistically significant in the dexamethasone group. No patient developed PCME in any of the three groups. No adverse events were reported during the study. Conclusion: 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.

Keywords: central foveal subfield thickness (CFT); interleukin 6 (IL-6); non-proliferative diabetic retinopathy (NPDR); pseudophakic cystoid macular oedema (PCME).

Figure 1

CONSORT flow diagram.

Figure 2

CFT (µm) was significantly lower in experimental Group 2 (topical dexamethasone) than in the placebo group 90 days after the surgery (F (2.86) = 4.46, p < 0.014). Differences in CFT between experimental Group 1 (topical bromfenac) and the placebo group, as well as between the two experimental groups, were not statistically significant; Bromfenac group n= 30; Dexamethasone group n= 30; Placebo group n = 30; CFT, central foveal subfield thickness.

Figure 3

CFT (µm) peaked one month after surgery, but the difference was not statistically significant (F (1.264, 108.75) = 0.498, p = 0.525); n = 90; CFT, central foveal subfield thickness; CFT 0, central foveal subfield thickness on the day of the surgery; CFT 1, central foveal subfield thickness on first postoperative day; CFT 7, central foveal subfield thickness seven days after surgery; CFT 30, central foveal subfield thickness 30 days after surgery; CFT 90, central foveal subfield thickness 90 days after surgery.

Figure 4

No interaction effect was observed between the time of CFT measurement (µm) and different groups (F (2.53, 108.74) = 1.032, p = 0.373); bromfenac group n = 30; dexamethasone group n = 30; placebo group n= 30; CFT, central foveal subfield thickness; CFT 0, central foveal subfield thickness on the day of the surgery; CFT 1, central foveal subfield thickness on first postoperative day; CFT 7, central foveal subfield thickness seven days after surgery; CFT 30, central foveal subfield thickness 30 days after surgery; CFT 90, central foveal subfield thickness 90 days after surgery.

Figure 5

Difference in IL-6 concentration (pg/mL) between the groups was not statistically significant (F (2, 87) = 1.227, p < 0.298); bromfenac group n = 30; dexamethasone group n= 30; placebo group n = 30.