OCT-A Finds Concurrent Vascular Changes in Demyelinating ON

These OCT-A findings suggest that vascular and structural degeneration progress in parallel, with subtle focal vascular changes already detectable before measurable ganglion cell loss; however, causality cannot be inferred from this analysis. This scan from the study shows a vessel density map of the radial peripapillary capillary plexus segmented into eight Garway-Heath sectors. Cool colors indicate lower vessel density, while warm colors indicate higher density. Photo: Bezerra S, et al. Clin Ophthalmol. 2026;20:569321. Click image to enlarge. Demyelinating optic neuritis (ON) is one of the most frequent causes of acute optic nerve dysfunction in young adults, typically presenting with unilateral painful monocular vision loss that develops over hours to days. It is strongly associated with multiple sclerosis (MS) and other inflammatory disorders, representing a typical manifestation of central nervous system demyelination. Demyelinating ON is an inflammatory condition, yet recent evidence shows that vascular involvement plays a relevant role in its pathophysiology. Researchers from Portugal believe that ON and MS should not be regarded as purely neurodegenerative disorders but as conditions in which inflammatory and vascular processes interact to drive tissue damage. Their recent study demonstrated that structural and vascular parameters derived from OCT and OCT-A can provide complementary insights into disease mechanisms. These microvascular alterations were subtle but detectable, suggesting that vascular dysfunction occurs in parallel with the inflammatory process.This prospective study, which was published in Clinical Ophthalmology, included 23 patients (mean age: 41.1 years; 75.9% female) with first unilateral demyelinating ON at a Portuguese tertiary center. Baseline and six-month assessments included best-corrected visual acuity (BCVA), peripapillary retinal nerve fiber layer (pRNFL), ganglion cell complex (GCC), focal loss volume, global loss volume and vessel densities from the radial peripapillary capillary (RPC) and macular superficial vascular plexus (SVP).“In summary, demyelinating ON follows a biphasic course characterized by acute RNFL swelling with focal vascular impairment, evolving into diffuse neuroaxonal thinning and microvascular attenuation,” the study authors wrote in their paper. “These observations suggest a parallel evolution of structural and vascular alterations rather than a direct causal relationship.”At baseline, the affected eyes showed increased pRNFL thickness compared with fellow eyes, particularly in nasal sectors, including nasal, inferonasal, nasal-upper and nasal-lower regions. At six months, the study detected significant thinning in the average pRNFL and temporal quadrant, accompanied by higher focal and global loss volume values. Longitudinally, progressive thinning occurred across all quadrants and optic nerve head (ONH) sectors in affected eyes, while fellow eyes remained stable. OCT-A revealed reduced vessel density in whole-image all-vessels, as well as in superior and inferior peripapillary sectors, at six months, with no significant longitudinal change after correction.“Taken together, these results suggest that vascular impairment in ON is not simply secondary to axonal atrophy but may reflect an early inflammatory or metabolic disturbance,” the researchers wrote. “Integrating OCT and OCT-A parameters provides complementary, but not interchangeable, information about ON pathophysiology, and their prognostic value remains to be clarified. Together, these imaging modalities may therefore offer associative markers that may support clinical assessment and future therapeutic research in demyelinating optic neuropathies.”Click here for the journal source. Bezerra S, Teixeira-Martins R, Ribeiro M, et al. Structural and microvascular changes in demyelinating optic neuritis assessed by OCT and OCT-A: a six-month longitudinal study. Clin Ophthalmol. 2026;20:569321. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.