Predictive value of intraocular lens power calculation formulae in children

Abstract

Purpose: To compare the accuracy of IOL power calculation formulae in a large cohort of children who underwent IOL implantation. Setting: Cairo University Children Hospital. Design: Retrospective, case series. Methods: A retrospective chart review of all children <14 years, who underwent primary or secondary IOL implantation in Cairo University Children Hospital from January 2016 to December 2019, was performed. Absolute prediction error (APE) was calculated for SRKII, SRK/T, Holladay I and Hoffer-Q formulae using the patients’ AL, keratometric (K) readings, implanted IOL power and refraction done two months postoperatively. Results: The study included 308 eyes of 255 patients with a mean age of 4.74 ± 3.19 years at the time of surgery. The mean K-reading was 43.42 ± 3.57 diopters (D) and mean AL was 22.01 ± 1.93 mm. The percentage of eyes with APE within 0.5D was 27.7% (85 eyes), 32.2% (99 eyes), 30.6% (94 eyes) and 25.4% (78 eyes) with SRK II, SRK/T, Holladay I and Hoffer-Q formulae, respectively. APE was significantly lower with the SRK/T formula (P≤0.004) and significantly higher with the Hoffer-Q formula (P≤ 0.002). There was a negative correlation between the age of the patient and the APE of the SRK II formula (P=0.02). Moreover, the SRK/T, Holladay and Hoffer-Q formulae APEs were affected by the average k-readings (P=0.019, 0.005 and 0.035) respectively. Conclusion: The SRK/T and Holladay I formulae were the most predictable formulae in IOL power calculation in pediatric eyes.