Lid Flare Measurement with Lateral Midpupil Distances

Area of Science:

• Ophthalmology
• Oculoplastics
• Medical Imaging

Background:

• Graves orbitopathy (GO) can cause various ocular complications, including upper lid abnormalities.
• Lateral lid flare (LLF) is a specific finding in GO that requires accurate detection.
• Existing methods for assessing LLF may lack standardized quantitative measurements.

Purpose of the Study:

• To evaluate the diagnostic accuracy of lateral midpupil eyelid distances for detecting upper lid lateral flare.
• To determine the sensitivity and specificity of specific measurements in identifying LLF.

Main Methods:

• Photographs of patients with GO and controls were graded by oculoplastic surgeons to identify LLF.
• Bézier lines were used to extract upper eyelid contours.
• Custom software measured five lateral midpupil eyelid distances.
• Receiver operating characteristic (ROC) curves were used to estimate sensitivity and specificity.

Main Results:

• High inter-rater agreement was observed for LLF grading (Fleiss' Kappa = 0.69).
• Lateral midpupil lid distances decreased from the eyelid center towards the lateral canthus.
• A specific lateral midpupil distance (2.5 mm medial to the lateral canthus) showed high sensitivity and specificity for detecting LLF.
• A measurement >= 60% of the margin reflex distance (MRD1) at this location indicated the presence of flare.

Conclusions:

• A single measurement of lateral midpupil eyelid distance, 2.5 mm from the lateral canthus, is a sensitive and specific diagnostic tool for upper lid lateral flare.
• This measurement offers a quantifiable and reliable method for diagnosing LLF in the context of Graves orbitopathy.