Characterizing Long-Chain 3-Hydroxy-Acyl-CoA Dehydrogenase Deficiency (LCHADD) Chorioretinopathy Using OCT and OCTA

To characterize structural and microvascular alterations in chorioretinopathy in patients with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) using optical coherence tomography (OCT) and OCT angiography (OCTA).

Thirty-six eyes from 19 patients with LCHADD were evaluated and categorized into six stages of increasing severity. Avanti and Solix OCTA devices were used to scan acquire 3 × 3-mm macular scans of the eyes. The thicknesses of the inner retina, outer retina, and choroid were measured from OCT scans. Vessel density (VD) and nonperfusion area (NPA) were calculated from en face projection-resolved OCTA in four slabs: the superficial vascular complex, intermediate capillary plexus, deep capillary plexus (DCP), and choriocapillaris (CC). The correlations (Spearman's rank) between these structural and angiographic metrics and traditional clinical metrics (the LCHADD severity, best-corrected visual acuity [BCVA], and plasma acylcarnitines) were investigated.

Pronounced thinning in the outer retina and choroid was observed, along with marked VD loss and increased NPA in the DCP and CC at severe stages. The outer retinal and choroidal thicknesses correlated with all traditional clinical metrics, VD/NPA in the DCP and CC were significantly correlated with the LCHADD severity and BCVA, and only VD/NPA in the CC were associated with plasma acylcarnitines.

Combined OCT/OCTA imaging enables visualization and quantification of structural and microvascular alterations in the chorioretinal slabs at different stages of LCHADD. The pathology of LCHADD impacts the deeper retinal plexuses more than the inner layers. OCT and OCTA parameters may improve understanding of the pathological changes in LCHADD chorioretinopathy and aid in monitoring disease progression.