The Distribution of Keratometry in a Population Based Study.

Area of Science:

• Ophthalmology
• Optometry
• Corneal Physiology

Background:

• Accurate keratometry measurements are crucial for refractive error correction and understanding corneal health.
• Previous studies have focused on specific age groups, limiting understanding of keratometry across the lifespan.
• The distribution of keratometry values in a broad age spectrum, from childhood to old age, remains incompletely characterized.

Purpose of the Study:

• To investigate the distribution and age-related changes in keratometry values within a wide population range (6-90 years).
• To identify demographic and clinical factors associated with variations in keratometry.
• To establish normative keratometry data across diverse age groups.

Main Methods:

• A cross-sectional study involving 2672 participants aged 6-90 years from two Iranian villages.
• Multi-stage random cluster sampling was employed for participant selection.
• Corneal imaging and keratometry measurements were performed using Pentacam, with statistical analysis of demographic and clinical data.

Main Results:

• Mean keratometry (mean-K) was 43.48 D, with flat and steep meridians at 42.98 D and 43.98 D, respectively.
• Mean-K showed a linear increase up to age 70, followed by a slight flattening, and was significantly higher in females and myopic individuals.
• Older age and female gender were significantly associated with mean-K in a multiple regression model; 31.62% of participants had at least 1.0 D of corneal astigmatism.

Conclusions:

• This study provides insights into keratometry changes across a wide age range, from childhood to senescence.
• Age and gender are significant variables influencing keratometry values.
• The findings contribute to a better understanding of normative corneal curvature and its variations throughout life.