Posters

Analysis of prediction error of intraocular lens (IOL) power calculation formulae in children aged less than two years

Poster Details

First Author: M.Diab EGYPT

Co Author(s):    S. Aissa              

Abstract Details

Purpose:

Most of the published studies have compared different intraocular lens (IOL) power calculation formulae in children older than two years. Children less than two years form a small subset of most such studies. Purpose of our study is to assess the accuracy of different IOL power calculation formulae in children less than two years.

Setting:

Ain shams university hospital Cairo Egypt

Methods:

We retrospectively analyzed records of 84 children (124 eyes) with congenital cataract in children (< 2 years age) who underwent primary IOL implantation. Data was analyzed for prediction error (PE) using the four commonly used IOL power calculation formulae. We calculated the absolute PE with each of the formulae and formula that gave least variability was determined. The formula, which gave the best PE, was determined.

Results:

Mean age at surgery was 11.7 ± 6.2 months. Absolute PE was found to be 2.27 ± 1.69 D with SRK II, 3.23 ± 2.24 D with SRK T, 3.62 ± 2.42 D with Holladay and 4.61 ± 3.12 D with Hoffer Q. The number of eyes with absolute PE within 0.5 D was 27 (21.1%) with SRK II, 8 (6.3%) with SRK T, 12 (9.4%) with Holladay and 5 (3.9%) with Hoffer Q. Comparison between different formulae showed that the absolute PE with SRK II formula was significantly better than others (p<0.001). PE with SRK II formula was not affected by age (p = 0.31), Keratometry (p= 0.32) and axial length (p=0.27). Axial length influenced the absolute PE with Holladay (p=0.05) and Hoffer Q formulae (p=0.002). Mean Keratometry influenced PE (p=0.03) with SRK T formula

Conclusions:

: In the existing literature there are conflicting reports of accuracy of various IOL power calculation formulae in children, although absolute PE tends to remain high with all present IOL power calculation formulae, SRK II was the most predictable formula. FINANCIAL INTEREST: NONE