[Partial coherent interferometry--an alternative method for intraocular lens power calculation performed by...

Area of Science:

• Ophthalmology
• Biomedical Optics
• Medical Instrumentation

Background:

• Accurate axial length measurement is crucial for intraocular lens (IOL) power calculation in cataract surgery.
• Traditional A-scan ultrasonography has limitations in precision compared to newer optical methods.
• Predicting postoperative refraction requires precise preoperative biometric data.

Purpose of the Study:

• To compare axial length measurements obtained from Zeiss IOLMaster and A-scan ultrasonography.
• To evaluate the accuracy of predicted postoperative refraction using both measurement techniques.
• To determine the reliability of IOLMaster versus ultrasonography for IOL power calculations.

Main Methods:

• Axial length was measured in 26 patients using both Zeiss IOLMaster and A-scan ultrasonography.
• Preoperative refraction was calculated using the SRK/T formula with specific A-constants for each method.
• Postoperative refraction was measured as spherical equivalent on the first postoperative day via autokeratorefraktometry.

Main Results:

• The mean axial length measured by IOLMaster was significantly longer (0.06 mm) than that from ultrasound (p < 0.001).
• A statistically significant correlation was found between IOLMaster-derived preoperative refraction and actual postoperative measurements (p = 0.03).

Conclusions:

• Zeiss IOLMaster provides longer axial length measurements compared to A-scan ultrasonography.
• IOLMaster appears to be a more reliable method for intraocular lens calculation in cataract surgery.
• Improved accuracy in axial length measurement can lead to better prediction of postoperative refractive outcomes.