Posters
Adjusting the Scheimpflug total corneal power in intraocular lens power calculation in eyes that have undergone keratorefractive surgery
Poster Details
First Author: M.Koaik CANADA
Co Author(s): C. Mehanna B. Noureddine J. Bleik S. Awwad
Abstract Details
Purpose:
Use of the Total Corneal Power (TCP) as an alternative to Simulated Keratometry (SimK) in intraocular lens (IOL) power calculations in patients who underwent either myopic or hyperopic kerato-refractive surgery (KRS).
Setting:
A retrospective chart review of 68 eyes who underwent keratorefractive surgery (KRS) followed by cataract surgery in the same eye at the American University of Beirut Medical Center (AUBMC).
Methods:
The cases were divided into 2 groups Group A with 40 post-myopic eyes and Group B with 28 post-hyperopic eyes. Pre-KRS and post-KRS and post-cataract (3 months) refractions, corneal topographies, Axial Length, implanted IOL type and power were collected. The Ideal Corneal Refractive Power (IRCP) was back-calculated using Double-K adjusted formulas. Adjusted Corneal Refractive Power (ARCP) was calculated using the regression formulas and was subsequently used in parallel with simK to calculate the absolute error of refraction using current IOL calculation formulas. Statistical comparison of the new devised tool to the traditional SimK-based formulas was done.
Results:
Group A showed better Mean Refractive Error in SimK derived calculations (p=0.012). ARCP-corrected Holladay 1 calculations did not show improved refractive outcome with a Mean Refractive Error of 1.69D ± 1.6. Group B results showed the lowest Mean Refractive Error (0.57D ± 0.4) in the ARCP-corrected HofferQ calculations. This was only statistically significant in comparison with SimK-based Holladay calculations (p=0.031).
Conclusions:
TCP- based regression formula may provide a more accurate tool for estimating IOL power in hyperopic patients. Myopic eyes tend to behave better with centrally based corneal power (simK).
Financial Disclosure:
None
