BACILLARY LAYER DETACHMENT IN PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT: Occurrence, Predictors, and Surgical Outcomes.

Abstract

To evaluate the frequency, clinical and optical coherence tomography (OCT) predictors, and postoperative anatomical and functional outcomes of bacillary layer detachment (BALAD) in eyes undergoing surgical repair for fovea-off rhegmatogenous retinal detachment (RRD). This retrospective, single-center observational study was conducted at a tertiary eye care hospital in India. Primary fovea-off RRD that underwent surgical repair between January 2020 and December 2024 were analyzed. Preoperative spectral-domain OCT images were reviewed for BALAD and other predefined retinal biomarkers. Clinical and imaging parameters were compared between the BALAD and non-BALAD groups. Univariate and multivariable logistic regression analyses identified predictors of BALAD formation. Occurrence rate and preoperative predictors of BALAD were analyzed, and postoperative macular reattachment, external limiting membrane/ellipsoid zone continuity, best-corrected visual acuity, and single-surgery success were assessed over 24 weeks. Two hundred and seventy primary fovea-off RRD eyes were analyzed. BALAD was detected in 51 eyes (18.9%). Younger age ( P = 0.014) and greater subretinal fluid height ( P = 0.002) were independent predictors of BALAD. Anatomical reattachment rates at 24 weeks were 88.5% in BALAD eyes and 77.3% in non-BALAD eyes ( P = 0.286). External limiting membrane/ellipsoid zone restoration occurred in 42.3% and 33.3%, respectively ( P = 0.247). Best-corrected visual acuity improvement trajectories were similar, though slower in BALAD eyes ( P < 0.001). Resurgery rates were comparable between groups ( P > 0.999). BALAD is a relatively common OCT feature in fovea-off RRD, predominantly affecting younger, fluid-rich eyes with higher subretinal fluid height. Its presence does not adversely affect anatomical reattachment or single-surgery success.