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Variations in corneal asphericity (Q value) between African-Americans and whites
Daniel G Fuller1, Danielle Alperin
1Cornea Contact Lens Service, The Eye Center, Southern College of Optometry, Memphis, TN 38104, USA. dfuller@sco.edu
Summary
Corneal asphericity differs significantly between African-Americans and whites, with African-American eyes being more prolate. These differences in Q value are most pronounced in opposing quadrants and are minimally affected by age, gender, or refractive error.
Area of Science:
- Ophthalmology
- Corneal topography
- Human genetics
Background:
- Corneal asphericity describes the curvature of the cornea.
- Understanding ethnic variations in corneal shape is crucial for refractive surgery and contact lens fitting.
- Previous research has not fully elucidated differences in corneal asphericity between African-American and white populations.
Purpose of the Study:
- To investigate and compare corneal asphericity (Q value) between African-American and white individuals.
- To determine if ethnicity influences corneal shape parameters.
Main Methods:
- A prospective cohort study involving 160 participants (80 African-American, 80 white).
- Corneal asphericity (Q value) was measured using Pentacam HR.
- Data were stratified by ethnicity, age, and spherical equivalent (SE) refractive error.
Main Results:
- African-American eyes exhibited significantly more prolate Q values (-0.26 ± 0.19) compared to white eyes (-0.20 ± 0.12).
- Significant ethnic differences were observed in specific age groups (30-39 years) and refractive error ranges.
- Differences were most prominent in opposing quadrants and between genders (males).
Conclusions:
- Corneal asphericity significantly varies between African-American and white populations.
- Ethnic differences in corneal shape are substantial and primarily located in specific quadrants.
- Age, gender, and spherical equivalent had minimal influence on these ethnic disparities.
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