Bacillary Layer Detachment Does Not Permanently Damage Vision

close view of a bruise near the eye, the face of a man with a hematoma
In a retrospective study, BLD was detected in only 8% of eyes, and reattachment occurred within 10 days.

Bacillary layer detachment (BLD) is a rare finding that can follow blunt ocular trauma, but an investigation shows they can resolve completely, without influencing visual or anatomical outcomes, according to a Canadian Journal of Ophthalmology report.

Researchers conducted a retrospective observational study to explore the clinical and visual outcomes of patients presenting with BLD on optical coherence tomography (OCT) in blunt ocular trauma. The study reviewed clinical fundus photographs and OCT scans of 77 eyes of 77 patients who have experienced blunt ocular trauma. The clinicians further analyzed patients for changes in their anatomy, such as subretinal hemorrhage, intrabacillary layer bleeding, subretinal fibrosis, and choroidal rupture and reattachment of BLD. Patients were also screened for changes in visual outcomes over subsequent follow-up visits.

The study identified 6 (8%) eyes with BLD. The time from the initial trauma to the presentation of BLD ranged from 1 to 7 days. In all 6 eyes, subretinal hemorrhage and choroidal rupture were noted, and foveal involvement was detected by OCT in 5 eyes. All patients presented with intrabacillary layer hemorrhage, and at the final visit, researchers noted reattachment of the bacillary layer and visual acuity (VA) improvement. Resolution of BLD ranged from 2 to 10 days. Secondary to subretinal fibrosis close to the fovea and subfoveal choroidal rupture was VA of 6/36 or less.

The researchers explain that it is possible BLD is low-occurring in cases of blunt ocular trauma due to various factors, including unawareness of the finding; poor-resolution OCT images, or the presence of associated macular findings, making the identification of BLD difficult.

“The time interval for resolution could depend on the extent of the intrabacillary layer and subretinal hemorrhage present in the eye. Also, there was no significant variation in the retinal thickness over the BLD following its resolution. Thus, the BLD resolution was not associated with retinal thinning or atrophy,” the researchers explain.

Study limitations include the small number of patients with BLD, leading to a knowledge gap related to the natural course of the BLD, its connection with improved VA, and other conclusions.


Venkatesh R, Agrawal S, Reddy NG, Pereira A, Yadav NK, Chhablani J. Bacillary layer detachment in acute nonpenetrating ocular trauma. Can J Ophthalmol. Published online June 27, 2021. doi:10.1016/j.jcjo.2021.05.017