Short-term efficacy and safety of intravitreal brolucizumab in diabetic macular edema: A retrospective interventional study

Abstract

Objectives: This study aims to evaluate the efficacy and safety of intravitreal brolucizumab (IVBr), a novel antivascular endothelial growth factor agent, in the treatment of diabetic macular edema (DME) by assessing both functional (visual) and structural (anatomical) improvements.

Materials and methods: A retrospective, interventional study was conducted at the ophthalmology outpatient department of Sultan Qaboos University Hospital at University Medical City. A cohort of twenty patients (60 injections) with DME received three IVBr injections (6 mg/0.05 mL) over 18 weeks. This cohort consists of 10 male and 10 female patients, with a mean age of 57.1 years (range: 35-81; standard deviation [SD] 14.37). The best-corrected visual acuity (BCVA) was measured and recorded in equivalent logMAR. The subfoveal macular thickness (SFMT) was assessed with optical coherence tomography. Statistical analysis was carried out using paired t-test, and 95% confidence intervals were calculated to compare changes in outcomes, with a significance threshold set at P < 0.05.

Results: The BCVA improved significantly from a baseline mean of logMar 0.36 (SD 0.7) to 0.22 (SD 0.5) after the third injection (P < 0.002). SFMT decreased from a mean of 517.75 μm (SD 160.27) to 287.95 μm (SD 101.31), P < 0.001. One patient developed intraocular inflammation, and no other major complications were observed. However, 35% of patients (n = 7) experienced inadequate visual improvement, attributed to underlying factors such as macular ischemia, retinal layer disorganization, disruption of the ellipsoid zone, and residual macular edema.

Conclusion: The study findings in this cohort demonstrated statistically significant improvement in BCVA and a substantial decrease in SFMT. However, more real-world studies are required to enhance the validation of this study's findings.

Keywords: Antivascular endothelial growth factor therapy; brolucizumab; diabetic macular edema; efficacy and safety; intravitreal injection.

Figure 1

Mean best-corrected visual acuity (BCVA) outcome value (n = 20 subjects) compared to baseline. The yellow bar showing the mean baseline BCVA, and the blue bars reflect postinjection outcome (Referenced in Results). BCVA: Best-corrected visual acuity

Figure 2

Mean optical coherence tomography measurements across treatment time points (n = 20 subjects). Yellow bar showing the mean baseline subfoveal thickness and blue bars showing postinjection outcome (Referenced in Results). OCT: Optical coherence tomography

Figure 3

Left eye macula optical coherence tomography of study patient showing diffuse diabetic macular edema with intraretinal fluid (Indicated with red arrow) and subretinal fluid (Indicated with yellow arrow). The thickness map (circle) showing massive edema. Pretreatment best-corrected visual acuity 0.50 (Referenced in results)

Figure 4

Left eye macula optical coherence tomography of the same patient in Figure 3 showing remarkable resolution of sub-retinal fluid and intra-retinal fluid after three intravitreal brolucizumab injections. The thickness map (circle) showing normal sub-foveal thickness. Posttreatment best-corrected visual acuity was LogMar 0.00 (Referenced in Results)