The Effect of Multiple Sclerosis on Nerve Fiber Layer of the Retina

Abstract

Abstract Background Multiple Sclerosis is a chronic idiopathic inflammatory demyelinating disease involving Central Nervous System white matter with relapsing-remitting nature. Optic neuritis is a common initial manifestation. Multiple Sclerosis is characterized by dual pathological process of inflammation and neurodegeneration. It causes prominent retinal neural ganglion cell layer loss in addition to related axonal loss which can be identified by thinning of RNFL seen in OCT. Patients and Methods This case control study was carried out at Ain Shams University Hospitals in MS clinic of neurology department and Ophthalmology outpatient clinics. with a total of 100 eyes, from 50 subjects, Group A (10 patients, 20 eyes): normal persons with normal eyes as a Control group and 40 patients (80 eyes) having multiple sclerosis who satisfied the inclusion and exclusion criteria subdivided into 2 groups,(group B) 20 patients having previous attack of Optic Neuritis & (group C) 20 patients not having previous Optic Neuritis. Informed consents were obtained from all subjects and ethics approval were obtained from Ain Shams University Hospitals Ethical Commitee: A complete ophthalmic history and ophthalmological examination were done for each subject. Visual acuity assessment using Auto Refractometer, refraction, uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) assessment using Snellen chart and also calculated in Logarithm of Minimum Angle of Resolution (LogMAR).Pupil reaction. Color vision assessment. Anterior segment detailed Slit Lamp examination. Posterior segment examination (ONH examination) using Slit lamp biomicroscopy, Volk +90 Diopter lens. Intraocular tension measured by Goldmann applanation tonometry. OCT to evaluate RNF layer thickness and c/d ratio. Results Our study results demonstrated that: VA & BCVA were statistically significant lower in MS group than the control group (P = 0.011, 0.006 respectively). Total, superior, inferior and temporal RNFL thickness were statistically significant lower in MS group than the control group(P = 0.003, 0.004, 0.028, 0.018 respectively), while there was no statistically significant difference between the two studied groups regarding nasal RNFL thickness. Total, all the four quadrants superior, inferior, temporal and nasal RNFL thickness were statistically significant lower in MS group with previous attack of ON compared with the MS group not having previous ON (P = 0.000, 0.000, 0.004, 0.004, 0.024 respectively). Conclusion This study also suggests a great role of ocular imaging techniques such as OCT as an effective noninvasive, high-resolution, non contact tool in mapping of subclinical retinal changes (GCIP layer) in MS patients. It may also serve as a diagnostic adjunct for monitoring disease activity and responses to neuroprotective drugs.