Intravitreal Brolucizumab for Diabetic Macular Edema: Outcomes in Treatment-Naive and Anti-VEGF-Switched Eyes over 48 Weeks.

Background

Brolucizumab has demonstrated efficacy for diabetic macular edema (DME) in pivotal clinical trials; however, comparative real-world data directly contrasting treatment-naive and anti-VEGF-switched eyes over a prolonged follow-up period remain limited. This case series evaluated 48-week functional, anatomical, and safety outcomes of intravitreal brolucizumab (IVBr) in treatment-naive and switched DME eyes in routine clinical practice.

Methods

This retrospective, two-center case series included 21 eyes with center-involving DME treated with IVBr between May 2022 and April 2024. Eyes were classified into a treatment-naive group (n = 10), which included only eyes with no prior anti-VEGF treatment for DME, and a switched group (n = 11), which included eyes previously treated with other anti-VEGF agents but not achieving dry macula. Dry macula was defined as the absence of fovea-involving fluid on OCT. BCVA (logMAR), central retinal thickness (CRT), dry macula rate, the proportion of eyes gaining ≥2 lines of BCVA, number of injections, mean injection interval, and intraocular inflammation (IOI) were assessed at baseline and at 6, 12, 24, and 48 weeks.

Results

At baseline, BCVA was 0.44 ± 0.27 in the treatment-naive group and 0.46 ± 0.28 in the switched group (p = 0.943), and CRT was 435.8 ± 150.1 μm and 461.8 ± 139.8 μm, respectively (p = 0.751). In the treatment-naive group, BCVA improved from 0.44 ± 0.27 to 0.24 ± 0.19 at week 48 (p = 0.023), and 5 eyes (50.0%) gained ≥2 lines. In the switched group, BCVA did not improve significantly (0.46 ± 0.28 to 0.41 ± 0.40; p = 0.461); 3 eyes (27.3%) gained ≥2 lines, and 1 eye (9.1%) lost ≥2 lines. CRT decreased significantly in treatment-naive eyes (435.8 ± 150.1 to 312.6 ± 106.2 μm, p = 0.020) and showed a non-significant reduction in switched eyes (461.8 ± 139.8 to 363.6 ± 127.4 μm, p = 0.067). Dry macula rates at week 48 were 40.0% and 27.3%, respectively (p = 0.659). Six switched eyes had prior intravitreal corticosteroid treatment for DME. One treatment-naive eye developed IOI, which resolved without permanent visual impairment.

Conclusions

In this retrospective case series, IVBr was associated with anatomical improvement over 48 weeks, with clearer functional and anatomical responses in treatment-naive eyes than in switched eyes. However, the switched group was older and had a more heterogeneous treatment history, including prior intravitreal corticosteroid treatment. The findings should therefore be interpreted as exploratory.