Accuracy of intraocular lens power calculation in pediatric cataracts with less than a 20 mm axial length of the eye.

INTRODUCTION

Selection of an appropriately-powered IOL is a complex issue, especially in eyes with an axial length of less than 20 mm in pediatric cataract.

OBJECTIVE

To assess the accuracy of IOL power calculation formulae in pediatric cataracts in eyes with an axial length of less than 20 mm.

MATERIALS AND

METHODS

The records of children less than 15 years old with congenital cataract who had undergone primary IOL implantation were analyzed.

MAIN OUTCOME MEASURES: The variables studied were axial length, keratometric values and the prediction error. The data were analyzed for prediction error determination using the SRK II, SRK T, Holladay 1 and Hoffer Q IOL power calculation formulae. The formula that gave the best prediction error was identified.

RESULTS

Twenty-eight eyes of 19 children were included in the study. The absolute prediction error was found to be 1.84 ± 2.09 diopters (D) with SRK II, 2.93±3.55D with SRK T, 3.63±4.06D with Holladay 1, and 4.83±5.02D with Hoffer Q. The number of eyes with the absolute prediction error within 0.5 D was 6 (21.42%) with SRK II, 4 (14.28%) with SRK T, 1 (3.57%) with Holladay 1, and 3 (10.71%) with Hoffer Q. The absolute prediction error with SRK II formula was significantly better than that with other formulae (P less than .001). The axial length influenced the absolute prediction error with Hoffer Q formula (P = 0.04). The mean keratometry influenced the prediction error with SRK T formula (P = 0.02), Holladay 1 formula (P = 0.02) and Hoffer Q formula (P = 0.02).

CONCLUSION

Although the absolute prediction error tends to remain high with all the present IOL power calculation formulae, SRK II was the most predictable formula in this study.