Perimetric testing of tritan deficiency.

Area of Science:

• Ophthalmology
• Genetics
• Visual Neuroscience

Background:

• Dominantly inherited juvenile optic atrophy (JOA) is a rare genetic disorder affecting vision.
• Understanding the specific visual field defects in JOA is crucial for early diagnosis and management.
• Previous studies have indicated visual field abnormalities, but detailed analysis using specific light stimuli is limited.

Purpose of the Study:

• To investigate the visual field sensitivity to different light stimuli in a family with dominantly inherited JOA.
• To characterize the pattern of visual field impairment, particularly concerning violet light sensitivity.
• To explore potential correlations between optic atrophy, visual acuity, and specific visual field deficits.

Main Methods:

• A computerized perimeter was used to assess visual field sensitivity in three family members with JOA.
• Testing involved violet, blue-green, and white test lights against a low-intensity white background.
• Relative light sensitivity was measured, with a focus on the central and peripheral visual field within 30 degrees.

Main Results:

• All three subjects exhibited a greater reduction in relative sensitivity to violet light in central visual fields compared to peripheral fields.
• Two subjects presented with classic signs of optic atrophy, centrocecal scotoma, and reduced visual acuity.
• One subject with normal visual acuity and no apparent optic atrophy showed peripheral visual field impairment in luminosity function.

Conclusions:

• Dominantly inherited JOA is characterized by a specific pattern of reduced violet light sensitivity, predominantly affecting central visual fields.
• Visual field testing with violet light may serve as an early indicator of JOA, even in individuals without overt optic atrophy.
• Impairment in luminosity function can also be present in the peripheral visual field, suggesting broader visual pathway involvement.