Low Contrast Visual Acuity Might Help to Detect Previous Optic Neuritis

Area of Science:

• Ophthalmology
• Neurology
• Neuroscience

Background:

• Optic neuritis (ON) is crucial for diagnosing multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD).
• Subclinical ON can be missed by standard high-contrast visual acuity (HC-VA) tests.
• Low-contrast visual acuity (LC-VA) can detect visual loss not apparent with HC-VA, particularly in MS.

Purpose of the Study:

• To evaluate the efficacy of LC-VA compared to HC-VA in detecting ON.
• To determine the optimal visual function test for identifying optic nerve involvement in demyelinating diseases.

Main Methods:

• Neuro-ophthalmic evaluation of 108 patients with prior ON and 35 controls.
• Assessment included best-corrected HC-VA, 2.5% LC-VA, and 1.25% LC-VA.
• Receiver operating characteristic (ROC) curve analysis and Youden index were used to determine sensitivity and specificity.

Main Results:

• 2.5% LC-VA showed the highest area under the ROC curve (AUC) for distinguishing ON from non-ON (0.835) and controls (0.754).
• 2.5% LC-VA demonstrated superior sensitivity (71.5%) compared to HC-VA (64.2%) in detecting ON history.
• Combining 2.5% LC-VA with HC-VA improved abnormality detection to approximately 85.4%.

Conclusions:

• 2.5% LC-VA is a sensitive, feasible, and rapid method for detecting ON.
• LC-VA is superior to HC-VA in identifying optic nerve involvement in demyelinating diseases.
• Combining 2.5% LC-VA and HC-VA offers the most comprehensive detection of ON.