Abstract

Purpose: to present a practical approach for unexplained visual loss.

Methods: In a prospective case series, we documented characteristics, clinical and paraclinical evaluations, relevant costs and the final diagnosis of patients referred to a tertiary eye hospital for evaluation of unexplained visual loss with no apparent structural abnormalities.

Results: 28 cases were documented. 9(32%) out of all referred patients were found to have nonretinal/ neurologic pathologies, while 19(68%) had a retinal/neurologic disorder. Different conditions masqueraded as non-organic visual loss including central visual pathway pathology, serous chorioretinopathy, occult macular dystrophy, inherited optic neuropathies and autoimmune retinopathies. In 30% of cases, the final diagnosis was made based on optical coherence tomography (OCT). Also, in many other cases, findings of OCT were helpful to rule out other diagnosis. Electrophysiologic tests including full field electroretinogram (ERG) and visual evoked potential (VEP) were the key in diagnosis of various conditions including central visual pathway pathology, retinal dystrophy, and autoimmune retinopathy. Unnecessary expenditure spent by each patient and all cases was estimated to be 72.5 US$ and 2028.8 US$ respectively (about 44.5 % of the total amount of expenditure spent on each case).

Conclusion: We proposed a practical approach for this group of cases in an attempt to prevent unnecessary paraclinical investigations and to alleviate the socio-economic burden of both patients on the health system.

Keywords: Visual loss; Unexplained visual loss; Electrophysiology; Macula; Dystrophy; Neuroophthalmology