An abundance of evidence demonstrates that thinning in the GCIPL on OCT can be quantified and used as a proxy for neurodegeneration. Additionally, studies have demonstrated that lesions in the optic radiations can lead to a characteristic homonymous pattern of degeneration in the bilateral retinas. It has not been studied whether lesions in MS lead to these patterns on OCT.

Participants in an ongoing collaborative study of visual outcomes underwent GCIPL analysis on OCT. Results from each eye were assessed by one rater visually and qualitatively for pattern of loss (superior, inferior, right/left sided, right/left upper/lower quadrant, or other) and size of lesion (small, medium large). Patterns of loss across both eyes were assessed and those consistent with homonymous hemianopia (OCT thinning on same field in each eye), were noted and confirmed by another rater.  In these patients brain MRI and medical record were examined to determine if lesions in the posterior visual pathway might account for the OCT findings.  Healthy control subjects (n=42) were reviewed for comparison.

Three of 121 patients with MS (age 41.9±11.7 years, median disease duration 6 (0-30), 69% female, and 83% RRMS) had homonymous pattern of GCIPL thinning.  All three patients had lesions in the visual pathway on MRI. One patient had a noted history of homonymous hemianopia on visual field testing, one had no history of visual complaints or findings on visual exam, and one had subjective visual complaints, but no clear pattern of findings on visual exam. None of the healthy controls had a homonymous pattern of thinning.

The contribution of postchiasmal lesions to visual dysfunction in MS is minimal.