BACILLARY LAYER DETACHMENT AND ASSOCIATED ABNORMALITIES IN RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To describe bacillary layer detachment and related abnormalities of the foveal bouquet in rhegmatogenous retinal detachment and assess their impact on photoreceptor recovery and full-thickness macular hole formation, using optical coherence tomography.

METHODS

Prospective cohort of 93 consecutive patients with fovea-off rhegmatogenous retinal detachment presenting to St. Michael's Hospital from January 2020 to April 2022, with gradable preoperative foveal optical coherence tomography.

RESULTS

23.7% (22/93) of patients had evidence of bacillary layer detachment and associated abnormalities. The mean fovea-off duration was 6.4 days (±5.6 SD). 86.4% (19/22) had foveal bacillary layer detachment, 15.8% (3/19) of which had cleavage planes extending from the outer nuclear layer into the myoid zone, and 14% (3/22) had an inner lamellar hole with a residual bridge of photoreceptor remnants (all of which progressed to full-thickness macular hole). Among patients with gradable optical coherence tomography at 3 months post-operatively, 80% (12/15) had ellipsoid zone discontinuity, which persisted in 41% (5/12) at 1 year.

CONCLUSION

Bacillary layer detachment was described for the first time in the setting of rhegmatogenous retinal detachment. This is hypothesized to occur from horizontal traction secondary to hydration/lateral expansion of the outer retina in the presence of the Müller cell cone scaffold. Bacillary layer detachment may render the fovea susceptible to further injury, possibly representing a pathophysiological basis for full-thickness macular hole formation in rhegmatogenous retinal detachment.