Retinal, Vascular, and Choroidal Remodeling After Non-Reperfused Central Retinal Artery Occlusion: A Longitudinal OCT...

Background: This study aimed to evaluate longitudinal changes in retinal layers, retinal vessel diameters, and choroidal thickness using optical coherence tomography (OCT) in patients with central retinal artery occlusion (CRAO). Methods: This retrospective study included 35 patients (70 eyes) diagnosed with unilateral CRAO between 1 January 2020 and 5 January 2024. Unaffected fellow eyes served as internal controls. OCT-based macular segmentation, retinal arterial and venous diameter measurements, and subfoveal and peripapillary choroidal thickness were assessed in the acute phase (<24 h) and at 1-month and 6-month follow-up visits. Subgroup analyses compared patients who received hyperbaric oxygen therapy (HBOT) with those who did not. Statistical analyses included t-tests, Mann-Whitney U, Wilcoxon signed-rank, and chi-square tests. Results: Retinal arterial and venous diameters showed significant narrowing during follow-up (arteries: 77.91  ±  11.77 µm to 70.74  ±  15.12 µm; veins: 130.94  ±  22.54 µm to 118.57  ±  20.61 µm; both p  <  0.05). Macular segmentation demonstrated marked thinning of the inner retinal layers, most prominently in the retinal nerve fiber layer and ganglion cell layer (40.09 ± 26.86 to 12.51 ± 4.99 µm and 61.20 ± 25.83 to 24.26 ± 12.11 µm, respectively; both p = 0.001). Subfoveal choroidal thickness progressively decreased over time (from 206.40 ± 34.91 µm to 178.86 ± 28.28 µm, p = 0.009). Peripapillary choroidal thickness increased across all quadrants at 6 months, most consistently in the inferior quadrant (p = 0.001). No significant differences in retinal or choroidal parameters were observed between HBOT-treated and non-treated patients. All cases exhibited persistent vascular occlusion without reperfusion. Conclusions: CRAO is characterized by progressive inner retinal atrophy, retinal vessel narrowing, and distinct temporal changes in choroidal morphology. The relative preservation and subsequent increase in peripapillary choroidal thickness during follow-up suggest dynamic choroidal involvement despite persistent occlusion. OCT-based macular segmentation and retinal vessel analysis provide objective biomarkers for longitudinal structural assessment in CRAO. By jointly quantifying retinal layer, retinal vascular, and choroidal remodeling, these findings may also provide reference data for future studies of structural evolution in non-reperfused CRAO.