Posters

Comparative analysis of intraocular lens power calculation methods (with no prior data) after myopic LASIK

Poster Details

First Author: A.Gupta INDIA

Co Author(s):    G. Parmar                    

Abstract Details

Purpose:

To compare the accuracy of intraocular lens (IOL) power calculation methods for postmyopic LASIK surgery patients without previous refractive surgery data using American Society of Cataract and Refractive Surgery (ASCRS) IOL Power Calculator.

Setting:

Tertiary Eye Care Centre in Central INDIA (Sadguru Netra Chikitsalya, Madhya Pradesh)

Methods:

Retrospective analysis of 10 eyes undergone cataract surgery after myopic LASIK. Four methods were used to calculate IOL power: Shammas-PL, Haigis-L, Potvin-Hill Pentacam and Barrett True-K No History method. Mean arithematic and absolute refractive prediction error and % of eyes within ±0.5D, ±1D of refractive prediction errors were calculated

Results:

The mean arithmetic refractive prediction error was -0.52D,-0.48,-0.24D and +0.21D of Shammas, Haigis-L, Barrett True-K and Potvin-Hill Pentacam method respectively (p=0.089). The least mean absolute prediction error of 0.52D was in Barrett True K method with prediction accuracy of 50% within ±0.5 D and 90% within ±1.0 D of target refraction. Thus, Potvin Hill method gives a slight hyperopic shift in contrast with other 3 ASCRS IOL power calculator methods which gave a slight myopic shift.

Conclusions:

All methods are comparable with no statistically significant difference. Method based on direct measurements of the anterior and posterior curvature, to calculate the “true” corneal power measured by a Scheimpflug device (Potvin hill method) gives a slight hyperopic shift in contrast with other 3 ASCRS IOL power calculator methods based on regression analysis which gave a slight myopic shift.

Financial Disclosure:

None