Optimal intereye difference thresholds by optical coherence tomography in multiple sclerosis: An international study

Area of Science:

• Neuro-ophthalmology
• Neuroimmunology
• Medical imaging

Background:

• Multiple sclerosis (MS) frequently involves the optic nerve, yet current diagnostic criteria lack specific markers for optic nerve lesions.
• Optical coherence tomography (OCT) is a valuable tool for detecting retinal thinning associated with optic nerve damage.

Purpose of the Study:

• To establish optimal intereye difference thresholds using OCT for identifying unilateral optic nerve lesions in MS.
• To assess the utility of these thresholds in diagnosing both symptomatic and asymptomatic optic nerve involvement in MS.

Main Methods:

• A multicenter international study involving 1,530 MS patients and healthy controls.
• Optical coherence tomography (OCT) measurements of retinal nerve fiber layer and ganglion cell + inner plexiform layer thicknesses.
• Receiver operating characteristic (ROC) curve analysis to determine optimal intereye difference thresholds.

Main Results:

• An optimal intereye difference threshold of 5μm for the peripapillary retinal nerve fiber layer was identified.
• An optimal intereye difference threshold of 4μm for the macular ganglion cell + inner plexiform layer was identified.
• Greater intereye differences in visual acuity correlated with greater intereye retinal layer thickness differences (p ≤ 0.001).

Conclusions:

• Intereye differences of 5μm (retinal nerve fiber layer) and 4μm (ganglion cell + inner plexiform layer) are robust thresholds for detecting unilateral optic nerve lesions in MS.
• These thresholds can aid in diagnosing optic nerve lesions, potentially informing future MS diagnostic criteria.
• The findings support the use of visual system assessments in MS clinical trials.