Accuracy of Corneal Power Measurements for IOL Power Calculation After Myopic LASIK

El-Hifnawy, Mohammad Abdul-Monaem

Accuracy of Corneal Power Measurements for IOL Power Calculation After Myopic LASIK

Sunday, April 27, 2014: 8:01 AM

Room 152 (Boston Convention and Exhibition Center)

Mohammad Abdul-Monaem M. El-Hifnawy, MD, Faculty of Medicine, University of Alexandria, Alexandria, Egypt

Mohamed Shafik Shaheen, MD, PhD, University of Alexandria, Alexandria, Egypt

Hany A. Helaly, MD, Faculty of Medicine, Alexandria University, Alexandria, Egypt

Amr F. Abu Elkheir, MD, Alexandria University, Alexandria, Egypt

Narrative Responses:

Purpose
To evaluate the accuracy of corneal power measurements for intraocular lens power calculation after myopic Laser in Situ Keratomileusis(Lasik).

Methods
The study was conducted on 45 eyes with previous myopic LASIK. Corneal power was measured by using manual keratometry, automated keratometry, IOLMaster and Pentacam. Different hypothetical IOL power calculation formulas were prformed for each case.

Results
The steepest mean K value was obtained by manual keratmetry(37.84±2.86 D) followed by automated keratmetry(37.31±2.83), then the IOLMaster mean K value(37.06±2.98) which was steeper than any other mean K value measured by the pentacam. Using EKR 4 mm with the Double-K SRK-T formula, The refractive outcome was good, with 97.8% of cases within±2 D, 80% of cases within ± 1 D and 42.2% of cases within ± 0.5 D. The best refractive outcome was obtained by the mean of " Shammas-PL + Double-K SRK-T formula using EKR 4 mm".

Conclusion
Pentacam Scheimpflug imaging using Holladay EKR 4 mm improved the accuracy of IOL power calculation in post myopic LASIK eyes. The best option is a combination of formulas. It is recommended to use the mean of "Shammas-PL+ Double-K SRK-T formulausing EKR 4 mm.