Bacillary Layer Detachment Tied to Macular Neovascularization Subtypes

Senile Macular Degeneration
Age Related Macular Degeneration With Neovascularization Of Torn And Rolled Up Retinal Pigmented Epithelium. (Photo By BSIP/UIG Via Getty Images)
Patients with subretinal fibrosis have significantly lower best-corrected visual acuity compared with nAMD patients without the condition, a study shows.

Bacillary layer detachment (BALAD) is associated with all types of macular neovascularization (MNV) subtypes in patients with neovascular age-related macular degeneration (nAMD), according to a case series published in Ophthalmology Retina. The study also shows that the occurrence of subretinal fibrosis in these patients is associated with worse visual outcomes. 

Researchers conducted a study of 30 eyes from 30 patients (19 women, 11 men) with treatment-naïve nAMD showing BALAD on optical coherence tomography (OCT). The mean patient age was 77.1±8 years (range 56-91 years). Investigators reviewed clinical records and multimodal imaging results between January 2015 and June 2019. The average follow-up period was 49.8±24 months (24-123 months). All participants underwent a loading phase of at least 3 monthly intravitreal anti-vascular endothelial growth factor (VEGF) injections. The average number of anti-VEGF doses administered during the study was 15±8 (range: 6-25 injections).

The MNV subtypes were distributed as follows: type 1 (63%), type 2 (27%), mixed type 1 and 2 (3%), type 3 (3%), and aneurysmal type 1 (3%), according to the study. After the anti-VEGF loading phase, the researchers found that best-corrected visual acuity (BCVA) significantly improved from baseline to 3 months (0.77±0.53 logMAR [Snellen equivalent, 20 of 118] vs 0.55±0.62 logMAR [Snellen equivalent, 20 of 71], P =.03). However, BCVA returned to baseline levels at 4 years (Snellen equivalent, 20 of 103, P =.6). 

The cumulative rate of subretinal fibrosis was 40% at 3 months, 63% at 1 year, 70% at 2 years, 73% at 3 years, and 77% at 4 years, according to the report. Investigators noted that eyes with subretinal fibrosis had significantly lower BCVA compared with eyes without subretinal fibrosis through-out the follow up period. Risk factors for subretinal fibrosis included hemorrhagic BALAD (adjusted hazard ratio [aHR] 2.02; 95% CI 1.54–3.22; P <.01) and the presence of subretinal hyperreflective material (aHR, 1.83; 95% CI 1.35–3.14; P <.01). 

“BALAD was identified as a distinctive phenotype of MNV activity in patients with nAMD that is associated with other exudative features, such as subretinal hyperreflective material (SRHM), subretinal and intraretinal fluids, and macular hemorrhage. We hypothesized the presence of a possible association between BALAD and subretinal fibrosis development,” researchers report. “If this will be confirmed in the future, BALAD may be considered a biomarker of poor functional outcomes and early subretinal fibrosis in patients with nAMD undergoing anti-VEGF therapy, regardless of the MNV subtype.” 

Study limitations include the limited sample size, the retrospective design, and lack of a comparative group. 

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.    


Ramtohul P, Malclès A, Gigon E, et al. Long-term outcomes of bacillary layer detachment in neovascular age-related macular degeneration. Ophthalmol Retina. Published online September 26, 2021. doi:10.1016/j.oret.2021.09.010