Optimizing precision in toric lens selection by combining keratometry techniques.

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Surgical Technology

Background:

• Toric intraocular lens (IOL) selection relies on precise preoperative measurements.
• Variability in keratometry technology can lead to outliers and affect IOL accuracy.
• Routine cataract surgery demands reliable methods for accurate toric IOL power calculation.

Purpose of the Study:

• To enhance the precision of toric intraocular lens selection.
• To minimize outliers caused by technology-dependent variability in preoperative assessments.
• To evaluate the impact of averaging measurements from different keratometers on measurement accuracy.

Main Methods:

• Compared preoperative measurements (sphere, astigmatism, axis) from a manual and four automated keratometers for 87 eyes.
• Defined a 'meld' value by averaging measurements across all five technologies for each parameter.
• Utilized Bland-Altman analysis, paired t-tests, and correlation coefficients to assess technology agreement with the meld, quantifying outliers.

Main Results:

• While statistical tests showed insignificant differences between individual technologies and the meld, precision analysis revealed clinically significant outliers.
• Averaging measurements from manual and automated keratometers reduced outliers for sphere (2%-46% to 1%-6%), astigmatism (6%-23% to 0%-2%), and axis (15%-27% to 3%-6%).
• Individual keratometry technologies produced a variable number of outliers, which could be overlooked when using a single device.

Conclusions:

• Multiple keratometry technologies yield similar average measurements but can produce overlooked outliers when used in isolation.
• Averaging measurements from manual keratometry with automated technologies significantly reduces measurement errors.
• This combined approach enhances the precision of toric intraocular lens selection in cataract surgery.