Cholesterol affects retinal nerve fiber layer thickness in patients with multiple sclerosis with optic neuritis

Background and purpose: To evaluate the associations between retinal nerve fiber layer (RNFL) thickness and lipid profiles in multiple sclerosis (MS). Methods: This study enrolled 136 patients with MS (n=272 eyes; 108 females, 28 males, mean age: 46.7±8.9years); 45% had a history of optic neuritis (ON). Subjects received optical coherence tomography (OCT) testing to assess RNFL thickness and visual acuity testing with Snellen charts. A subset of 88 patients received pattern reversal visual-evoked potential (PRVEP) testing. Lipid profiles consisting of serum high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and total cholesterol (TC) levels were obtained within ±6months of OCT. Regression analyses were used to assess the associations between RNFL thickness and lipid profile variables. Results: Low RNFL thickness (P=0.008) and higher PRVEP latency (P=0.017) were associated with high LDL cholesterol >100mg/dl status. Low RNFL thickness (P=0.008) and higher PRVEP latency (P=0.043) were associated with high HDL cholesterol levels. Low RNFL thickness was also associated with HDL cholesterol >60mg/dl status (P=0.001) and with TC >200mg/dl status (P=0.015). The probability of average RNFL thickness in the lowest tertile (≤33rd percentile) was associated with interactions between TC >200mg/dl status (P=0.001, odds ratio=7.5, 95% confidence interval=2.7-21) with affected/unaffected by ON status. Conclusions: High cholesterol adversely affects RNFL thickness in patients with MS with ON.