Internal limiting membrane detachment in acute Central Retinal Artery Occlusion: clinical features, multimodal imaging, outcomes & prognostic biomarker.

Purpose: To report the clinical features, multi-modal imaging characteristics and their corroboration, and prognostic value of internal limiting membrane detachment (ILMD), a novel OCT biomarker in acute CRAO.

Design: Retrospective observational case-control study at institutional tertiary eye care centers.

Methods: 60 eyes of 60 patients of acute CRAO with optical coherence tomography (OCT) at baseline were included. Eyes were grouped in (a) With ILMD; (b) With no-ILMD. Multimodal imaging correlation, BCVA change and binary logistic regression were studied.

Results: Eighteen eyes (30%) were noted to have ILMD. At presentation, ILMD on OCT corroborated with macular non-perfusion with enlarged foveal avascular zone both on OCT-angiography (OCTA) and fundus fluorescein angiography (FFA). On follow-up, ILMD had resolved in all cases with fragmentation, disruption and atrophy of the retinal layers. Logistic regression showed poor baseline visual acuity was significantly associated with the odds of ILMD [Odds Ratio (OR) 31.02, p = 0.0018, 95% confidence interval: 1.81-529] while controlling for potential confounders including age (p = 0.60), gender (p = 0.316) duration of symptoms (p = 0.114), follow-up duration (p = 0.450) and final BCVA (p = 0.357). Eyes with ILMD and no-ILMD had a baseline BCVA of 2.62 LogMAR (light perception) and 2.05 LogMAR (Snellen equivalent 20/2000), respectively. On follow up, none of the eyes with ILMD showed any improvement. In contrast, nine (21.4%) eyes in no-ILMD had a vision of 20/400 and above with a mean final visual acuity of 1.87 + 0.78 LogMAR (p = 0.000).

Conclusion: ILMD correlated with macular non-perfusion and poor baseline visual acuity which showed no improvement on follow-up, suggesting it to be poor prognostic biomarker.