Brolucizumab Shows Visual Gain Effects Without RNFL Thinning in nAMD Eyes

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Intravitreal brolucizumab therapy in patients with neovascular age-related macular degeneration (nAMD) was associated with short-term morphological and functional visual gain effects without peripapillary retinal nerve fiber layer (RNFL) thinning, according to new research.¹

The single-center study based in South Korea suggests patients' best-corrected visual acuity (BCVA) significantly improved 3 months after brolucizumab injection, while their global peripapillary RNFL thickness remained unchanged during the same follow-up period after injection.

“The RNFL thickness of the temporal sectors significantly decreased only 1 month after injection, presumably owing to the anatomical improvement of macular lesions,” wrote the investigative team. “Therefore, a single intravitreal brolucizumab injection seems to be safe in terms of peripapillary RNFL damage in patients with intractable nAMD."

The retrospective, observational, and consecutive case series study, led by Daniel Duck-Jin Hwang, Department of Ophthalmology, Hangil Eye Hospital, included a total of 22 patients diagnosed with nAMD between April 2021 - March 2022 at the study hospital. Among the 22 patients, 19 were male (86.36%) and the mean age was 67.77 years. All patients previously received anti-vascular endothelial growth factor (anti-VEGF) therapy for nAMD and showed poor response with fluid accumulation on spectral domain optical coherence tomography (SD-OCT).

At baseline, all participants underwent fluorescein angiography and indocyanine green angiography, and one day after injection, investigators performed intraocular pressure (IOP) measurement and slit-lamp microscopy. Then, at every 2-week, 1-month, and 3-month visit, BCVA and IOP were assessed using slit-lamp biomicroscopy, fundus photography, and SD-OCT. Additionally, the SD-OCT program measured the peripapillary RNFL thickness and averaged the total 360-degree readings to obtain the global RNFL thickness.

The analysis showed eyes treated with intravitreal brolucizumab had significantly improved BCVA 3 months after injection compared with baseline measurements (logMAR, 0.45 ± 0.25 vs. 0.38 ± 0.25; P = .012). Data showed the mean IOP at baseline was 14.72 ± 3.45 and 3 months after injection, the intravitreal brolucizumab group experienced a borderline IOP reduction effect (13.72 ± 3.57 mmHg), but the difference was nonsignificant (P = .093).

Additionally, compared with the baseline, the temporal RNFL thickness in the intravitreal brolucizumab-treated eyes had significantly decreased after 1 month (P = .045), but the significance did not remain (P = .375) and the RNFL thickness recovered to baseline at 3 months. However, RNFL thickness of the global, superior temporal, inferior temporal, inferior nasal, nasal, and superior nasal sections did not change substantially with intravitreal brolucizumab treatment.

The central macular thickness of eyes treated with brolucizumab significantly decreased after each follow-up visit, compared to baseline. At 3 months after brolucizumab injection, the analysis showed a significant increase in CMT compared to 1 month after injection (P = .007).

In their summary, Hwang and colleagues cited the limitations of the retrospective study design, noting the recent commercialization of brolucizumab in South Korea limited the number of target patients and only allowed for a relatively short follow-up period. But, the team believes their findings may alleviate the concerns of physicians regarding RNFL damage after intravitreal brolucizumab injection.

“Despite these limitations, this study provides valuable data regarding the effect of brolucizumab injection on peripapillary RNFL thickness in non-naive patients with nAMD,” investigators wrote.

References

1. Jun SY, Hwang DD. Short-term effect of intravitreal brolucizumab injections in patients with neovascular age-related macular degeneration on retinal nerve fiber layer thickness. Sci Rep. 2023;13(1):6685. Published 2023 Apr 24. doi:10.1038/s41598-023-32024-6