2020–2021 BCSC Basic and Clinical Science Course™
Chapter 4: The Patient With Decreased Vision: Classification and Management
The initial goal in the assessment of reduced vision in any patient is to localize the cause of vision loss to a specific part of the visual pathway(s). Decreased vision may arise from refractive errors or abnormalities in the ocular media, retina, optic nerve, optic tracts, visual radiations, and occipital cortex. Evaluation of the patient with vision loss requires consideration of the clinical history together with results of the examination and ancillary testing, as outlined in Chapter 3, to determine causation and management.
Ocular Media Abnormality
Irregularities or opacities of the ocular media tend to reduce visual acuity, but they do not affect pupils, color vision, or the appearance of the posterior pole. Corneal disease such as dry eye or epithelial basement membrane dystrophy, as well as lenticular abnormalities, may be identified by careful slit-lamp examination. These conditions may cause generalized reduction of sensitivity on automated perimetry testing. These conditions may be subtle enough to be missed during a cursory ophthalmic examination; they may be diagnosed only during a thorough neuro-ophthalmologic evaluation in patients with presumed unexplained vision loss.
Excerpted from BCSC 2020-2021 series: Section 5 - Neuro-Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.