Optical Coherence Tomographic Measures of Retinal Structure Do Not Correlate with Serum Vitamin D Levels in Multiple Sclerosis Patients

Background: Vitamin D levels are associated with MS disease risk and severity clinically and radiographically. Retinal nerve fiber layer (RFNL) thickness, as measured by optical coherence tomography (OCT), also correlates with MS disease severity. It is not clear whether vitamin D might influence retinal and optic nerve changes in multiple sclerosis (MS) patients. Objectives: We sought to determine whether vitamin D levels are associated with retinal structure in MS patients, hypothesizing a neuroprotective role for higher levels. Methods: We conducted a retrospective review of spectral-domain OCT findings from our MS population in 53 patients (104 eyes) at various stages of disease (mean duration, 9.7 years, 79% RRMS). 15% of eyes had a history of optic neuritis; none had alternative ocular pathology. Serum vitamin 25(OH)-D levels and spectral-domain OCT testing were conducted within 6 months of each other. OCT measures included total macular and ganglion cell layer volume and peripapillary RNFL thickness. Results: None of the OCT measures correlated with vitamin D levels. There were non-significant trends toward lower tissue volumes with higher vitamin D levels, in contrast to our hypothesis. These findings were similar in the larger subgroup without a history of optic neuritis. Conclusions: We did not identify an association between measures of retinal ganglion cell axonal or somatic integrity and random vitamin D levels in an unselected cohort of MS patients. However, vitamin D values may vary significantly over short intervals, especially with supplementation. Given the evidence of vitamin D’s role in MS, a prospective study of changes in retinal structure over time with frequent monitoring of levels would be optimal.