English

Abstract

BACKGROUND Attenuation of vision may be due to underlying organic condition or due to functional visual disorder or malingering if secondary gain is associated. Causes of pathological vision loss include advanced primary open angle glaucoma, hereditary macular dystrophies and optic neuropathies. Problem in establishing diagnosis is faced where superimposition of organic and functional visual loss is there. Distinction between functional visual loss and pathological visual loss is made by thorough and careful examination of the patient by applying basic rules and tools of ophthalmology in which examining surgeon is well versed, but patient is unaware. During routine practice, every ophthalmologist encounters patients with nonorganic vision loss. The purpose of the article is to demonstrate how to distinguish between normal visual function without missing any organic visual loss. Examination of such patients requires number of tests including baseline visual acuity, pupillary reactions, slit lamp examination of anterior segment, fundus examination, visual field analysis, optical coherence tomography, visual evoked potential and electroretinography. By proving integrity and functioning of visual system, diagnosis of functional visual loss can be confirmed. Once the conclusive diagnosis is established, it is to be revealed with caution to the patient/patient’s attendant as it can lead to medico legal issues. Here, we present series of cases who presented to us in a tertiary care center of North India during a period of six months in the year of 2019 where case 1 and case 2 presented with decreased vision due to underlying pathological condition, case 3 presented with reduced vision due to functional visual disorder. Case 4, 5 and 6 provided decisive evidence of malingering. KEY WORDS Fogging, Hysterical Visual Loss, Malingering, Menace Reflex, Optokinetic Nystagmus.