Loss of contrast sensitivity

Specialty: Ophthalmology.

• faded vision
• difficulty distinguishing contours
• alteration of gray discrimination

Why it occurs

• Incipient or moderate nuclear cataract
• Subclinical optic neuritis or sequelae of previous demyelination of the optic nerve
• Early onset chronic open angle glaucoma (early damage to retinal ganglion cells of the magnocellular pathway)
• Age-related macular degeneration (AMD) in early stages
• Early non-proliferative diabetic retinopathy with involvement of foveal flow
• Persistent mild corneal edema

Initial workup

Quantitative evaluation using a Pelli-Robson contrast sensitivity chart (measures the ability to discriminate letters of constant size with a progressive decrease in gray contrast); Optical Coherence Tomography (OCT) of the optic nerve (nerve fiber layer) and macula; Dual-frequency computerized visual campimetry (FDT); Visual Evoked Potentials (VEP) to document nerve conduction abnormalities in the visual pathway.

Standard management

• There is no pharmacological treatment available that selectively restores contrast sensitivity when there is axonal damage or physical media opacity.
• Lutein with Zeaxanthin and antioxidants orally — AREDS2 formulation, used to slow the progression of photoreceptor damage and improve macular pigment density in patients with AMD
• Sodium hyaluronate artificial tears (symptomatic to optimize the tear film and minimize superficial refractive aberration).