OCT based evaluation of retinal changes in multiple sclerosis

Background: Optical coherence tomography is a non-invasive imaging technique routinely used in ophthalmology to visualize and quantify the layers of the retina. It also provides information on optic nerve head topography, peripapillary retinal nerve fibre layer thickness and macular volume which correlate with axonal loss. These measurements are of interest in optic neuropathies and in multiple sclerosis. The OCT parameters are now used as endpoints in neurologic clinical trials.Methods: A prospective study involving 30 patients of multiple sclerosis and equal number of age and sex matched controls were subjected to evaluation of retinal changes (peripapillary retinal nerve fiber layer and central macular thickness) using Zeiss Cirrus HD-OCT machine. The results collected were then subjected to statistical analysis.Results: Significant RNFL thinning was seen in patients of multiple sclerosis compared to the age and sex matched controls. Marked thinning was seen in superior and temporal quadrants of right eye (p value of 0.002 and 0.008 respectively) and all quadrants in left eye with a p value of < 0.001. Patients with multiple sclerosis for more than 5 yrs showed statistically significant RNFL thinning in the superior quadrant of right eye (p<.005), however, no such changes were seen in rest of the quadrants of right eye and in none of the quadrants of left eye Significant RNFL thinning was seen in the patients of multiple sclerosis without prior history of optic neuritis than patients with prior history of optic neuritis which was statistically significant with p value of .001.Conclusions: Patients with multiple sclerosis for more than 5 yrs showed statistically significant RNFL thinning in the superior quadrant of right eye (p<.005). Significant RNFL thinning was seen in the patients of multiple sclerosis without prior history of optic neuritis than patients with prior history of Optic neuritis which was statistically significant with p value of .001. No significant changes were seen in central macular thickness in multiple sclerosis compared to the controls which was corroborated by statistical analysis (p value of 0.37).