White-to-white corneal diameter in the Tehran Eye Study

Area of Science:

• Ophthalmology
• Corneal topography
• Population studies

Background:

• Corneal diameter is a key biometric parameter in ophthalmology.
• Understanding population-specific corneal dimensions is crucial for diagnosing conditions like microcornea and macrocornea.

Purpose of the Study:

• To determine the mean corneal diameter in the adult population of Tehran.
• To identify factors influencing corneal diameter within this population.

Main Methods:

• A stratified cluster sample of 410 individuals aged 14+ from Tehran was analyzed.
• Corneal diameter (horizontal limbus-to-limbus distance) was measured using Orbscan II.
• Linear regression was employed to assess correlations, adjusting for cluster sampling effects.

Main Results:

• The mean corneal diameter was 11.68 mm.
• No significant correlation was found with age, but a positive correlation with anterior chamber depth was observed.
• The 95% range for corneal diameter was 10.76-12.60 mm.

Conclusions:

• The mean corneal diameter in Tehran is comparable to other populations.
• Slightly adjusted cutoff values for macrocornea (>12.60 mm) and microcornea (<10.76 mm) may be appropriate for this population.