Racial differences in normal values of proptosis

Area of Science:

• Ophthalmology
• Anthropometry
• Clinical Measurement

Background:

• Proptosis, or eye protrusion, is a clinical sign that can indicate underlying health conditions.
• Establishing accurate normal ranges for proptosis is crucial for diagnosing orbital and endocrine diseases.
• Existing normative data for proptosis may not adequately account for racial variations.

Purpose of the Study:

• To measure and compare proptosis values in Black and white adult populations.
• To determine if significant differences in proptosis exist between racial groups.
• To propose revised upper limits of normal for clinical proptosis assessment.

Main Methods:

• Proptosis was measured using a Luedde exophthalmometer.
• Measurements were taken by a single experimenter in 402 Black and 325 white adults.
• Participants were screened to exclude endocrine disease and orbital pathology.

Main Results:

• Black subjects demonstrated significantly higher mean proptosis values compared to white subjects.
• Specific upper limits of normal were identified for each sex within both racial groups.
• Proposed upper limits: White females 19 mm, white males 21 mm, Black females 23 mm, Black males 24 mm.

Conclusions:

• Racial differences in normal proptosis values are significant and should be considered in clinical practice.
• The proposed race- and sex-specific upper limits can enhance the diagnostic utility of exophthalmometry.
• Accurate normative data is essential for the reliable detection of abnormal eye protrusion.