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Age-Related Changes in Corneal Astigmatism.
Journal of Refractive Surgery (Thorofare, N.J. : 1995)
|October 10, 2017
Summary
Corneal astigmatism changes non-linearly with age, accelerating in middle age towards an against-the-rule shift. This age-related trend is crucial for accurate astigmatism correction during surgery.
Area of Science:
- Ophthalmology
- Optometry
- Corneal Physiology
Background:
- Corneal astigmatism is a significant factor in visual acuity.
- Understanding age-related changes in corneal astigmatism is essential for refractive correction.
Purpose of the Study:
- To analyze age-related changes in corneal astigmatism.
- To develop a predictive model for corneal astigmatic change based on age.
Main Methods:
- Cross-sectional study of 3,769 individuals' right eyes.
- Scheimpflug tomography used to measure total, keratometric, anterior, and posterior corneal astigmatism.
- Analysis of corneal astigmatism changes using smoothing fitting curves and age-specific calculations.
Main Results:
- Identified age turning points at 36 and 69 years for total corneal astigmatism.
- Observed an accelerated against-the-rule shift (0.45 D/decade) between ages 36-68.
- Developed a non-linear model and formula to estimate age- and type-specific astigmatism correction.
Conclusions:
- Corneal astigmatism exhibits a non-linear progression towards against-the-rule, peaking in middle age.
- The rate of astigmatic change varies significantly with age.
- These findings are critical for optimizing surgical correction of astigmatism.
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