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Unexplained Visual Loss; Different Etiologies, Costs and Diagnostic Guideline Proposal

Unexplained visual loss (UVL) is one of the challenging problems are faced by ophthalmologists and is defined as decreased best-corrected visual acuity (BCVA), which cannot be explained by underlying pathology of visual pathways or is out of proportion of identifiable lesion [1,2]. UVL is a common problem among patients presenting to ophthalmic care services and neuro-ophthalmology clinic, which poses distress and anxiety to both patients and physicians [3,4]. It is necessary to search for any definable pathology of decreased vision before arriving at the diagnosis of functional vision loss (FVL) which is a label that affects further investigations as well as treatment strategies [5]. Scott and Egan have shown that organic etiologies account for a large proportion of UVL with more than half of the patients with FVL had concurrent organic disease [6]. Herein, we describe the final diagnosis of 28 cases with application of our step-by-step approach to discover the etiology of UVL more rapidly to prevent unnecessary and irrelevant paraclinical testing. Since there is not a well stablished diagnostic protocol for UVL, we believe that the application of this approaches would decrease the cost imposed on both the patients and the health system in addition to other benefits such as protection of patients from exposure to side effects of some diagnostic modalities.