Anti-VEGF Therapy Associated with Decreases in RGCL Thickness in nAMD Treatment

Yaser Abu Dail

Monotherapy with intravitreal aflibercept, bevacizumab, and ranibizumab was associated with comparable significant decreases in retinal ganglion cell layer (RGCL) thickness in patients with neovascular age-related macular degeneration (nAMD).

The comparable decreases were additionally observed in central macular thickness (CMT), macular volume (MV), intraretinal fluid (IRF) and subretinal fluid (SRF) in patients with nAMD during the first two years of treatment.

There were no significant differences observed in either best-corrected visual acuity (BCVA) or retinal nerve fiber layer (RNFL) thickness between the three intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents.

“These results may help to simplify the design of further studies investigating the influence of anti-VEGFs on RGCL and RNFL thickness, as the three could then be used interchangeably, allowing the inclusion of patients with therapy switching and longer follow-up periods,” wrote study author Yaser Abu Dail, Department of Ophthalmology, Saarland University Medical Center, UKS.

Although anti-VEGFs remain the standard treatment of nAMD, long-term side effects remain a concern due to their need for long-term use. Chronic suppression of VEGF has been linked to a downstream effect on RNFL and a significant reduction in RGCL thickness.

However, determining causality between anti-VEGF treatment and RGCL and RNFL thinning has been difficult, as separating the effect of nAMD on RGCL and RNFL from the effect of the anti-VEGF has proven a challenge.

The retrospective cohort study from Dail and colleagues focused on the comparison between the impact of monotherapy with anti-VEGF medications (ranibizumab, aflibercept, and bevacizumab) on RGCL and RNFL during a two-year study period. In the analysis, investigators divided the patients by medication group, with 34 eyes in the ranibizumab group, 38 eyes in the bevacizumab group, and 25 eyes in the aflibercept group.

The effect of the anti-VEGF medications on RGCL, RNFL, BCVA, CMT, MV, and presence of retinal pigment epithelial atrophy (RPE-atrophy), IRF, and SRF were measured as the main outcome. Outcome measures were recorded at the time of first injection, 1, and 2 years after the treatment and investigators compared the measures longitudinally and between each group.

At baseline, there were no significant differences between groups in age, gender, number of intravitreal injections at 1 and 2 years, RGCL and RNFL thickness at the inner and outer rings, BCVA, CMT, the presence of IRF, SRF and RPE-atrophy or intraocular pressure (IOP). The MV was noted for being significantly higher in the aflibercept group than the ranibizumab group at baseline.

The findings indicate the RGCL thickness, MV, CMT, and the presence of IRF and SRF decreased significantly for all three medication groups (P <.05 for all) with no significant difference between groups over the two-year follow up (P > .10 for all).

The decrease in RNFL thickness was not significant within or between medication groups after the two-year follow-up (P >.055 for all). Meanwhile, RPE-atrophy was found to increase significantly after 2 years in all three groups (P <.028 for all) with no significant differences between groups at all three time points (P >.307 for all).

Compared to baseline, the BCVA was comparable between the three groups over the 2-year follow–up period (P >.22 for all).

The study, “Impact of intravitreal ranibizumab, aflibercept and bevacizumab on retinal ganglion cell and nerve fiber layer thickness in Neovascular age-related macular degeneration,” was published in Acta Ophthalmologica.