Cronicon OPEN ACCESS EC MICROBIOLOGY EC MICROBIOLOGY Review Article Atypical Ocular Manifestations of Multiple Sclerosis and Side Effects of Drugs: A Review Khadija Alfaqih*, Ashjan Bamahfouz, Raghad Adraj, Enas Alkhoutani, Amal Alkhotani and Elham Alharbi College of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia Citation: Khadija Alfaqih., et al. “Atypical Ocular Manifestations of Multiple Sclerosis and Side Effects of Drugs: A Review”. EC Microbiology 16.2 (2020): 01-07. *Corresponding Author: Khadija Alfaqih, College of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia. Received: December 16, 2019; Published: January 06, 2020 Abstract Multiple sclerosis (MS) is a chronic, irreversible, and disabling neurodegenerative disease affecting a young and working popula- tion. Its debilitating disabilities result in a huge disease burden. Early detection of MS has become possible due to new technologies, in particular early detections of its ocular manifestations. However, MS has both typical and atypical ocular presentations. We review published literature describing different ocular manifestations of MS to enable vigilant primary physicians to correlate systemic signs and symptoms with MS. We also outline some unusual phenomena that can help ophthalmologists suspect atypical MS. Keywords: Multiple Sclerosis; Optic Neuritis; Optical Coherence Tomography; Magnetic Resonance Imaging; Neuro-ophthalmology Introduction Multiple sclerosis (MS) is the most common neuro-immunological disorder, with prevalence in 2016 of 2.22 million. There has been a 10% increase in age-standardized prevalence since 1990 [1,2]. Higher altitude, younger age-group, female gender, low serum levels of vitamin D, smoking, childhood obesity, and infection with the Epstein-Barr virus are likely to play roles in disease development [3,4]. Genetic risk for MS has not yet been established; therefore, there is no definite measure or laboratory marker for the diagnosis of MS [5]. According to revised classification, MS can be grouped as relapsing-remitting MS, clinically isolated syndrome, radiologically isolated syndrome, primary-progressive MS and secondary progressive MS [6]. Clinicians are strongly advised to use clinical history and exami- nation, imaging, and other available data to differentiate demyelination related to MS from that related to other ailments [7]. Magnetic Resonance Tomography (MRI) has revolutionized the differential diagnosis of MS from other neurological conditions. MRI and testing of cerebrospinal fluid help to identify different pathological substrates of MS, such as inflammation, demyelination, and neuro-axonal loss [8,9]. Treatment of MS includes pharmacotherapy, diet, and rehabilitation. In the last decade, the FDA has approved 13 new medications, both parenteral and oral, for the treatment of MS, but their use is limited due to their prohibitive costs [10-13]. As MS is a debilitating condition, patients with MS need rehabilitation and changes in diet [14,15]. MS involves myelinated nerves, including motor neuron efferent pathways, sensory nerve fibres, intracranial and autonomous nervous systems, and nerve fibres involving the eyes [16]. In optic neuritis due to MS, a common presentation of MS, the patient presents with an acute, unilateral, ad painful decrease in visual acuity, recovering within a few weeks but with residual stigma [8]. Visual effects are com- mon in patients with MS, and most changes are irreversible, with the disease mainly targeting the afferent visual pathway (retina, optic nerve, chiasma, and tract) [17].