Holladay, SRK/T formulas best for pediatric cataract

This review of data from the Infant Aphakia Treatment Study found that the Holladay 1 and SRK/T formulas gave equally good results and had the best predictive value for IOL power calculation in infant eyes.

The authors analyzed the prediction error of the commonly used IOL power calculation formulas Hoffer Q, Holladay 1, Holladay 2, Sanders-Retzlaff-Kraff (SRK) II and Sanders-Retzlaff-Kraff theoretic (SRK/T) in 43 infants who underwent primary IOL implantation in the Infant Aphakia Treatment Study. The mean axial length of the infants was 18.1 ± 1.1 mm (in 23 eyes, it was < 18.0 mm), and the average age at surgery was 2.5 ± 1.5 months.

Holladay 1 showed the lowest median absolute prediction error (1.2 D); a paired comparison of medians showed clinically similar results using the Holladay 1 and SRK/T formulas (median difference, 0.3 D). Comparison of the mean absolute prediction error showed the lowest values using the SRK/T formula (1.4 ± 1.1 D), followed by the Holladay 1 formula (1.7 ± 1.3 D). Eyes with globe axial length of less than 18 mm had the largest mean and median prediction error and absolute prediction error, regardless of the formula used.

They conclude that IOL implantation for eyes of infants younger than 7 months of age presents many challenges, including selection of an appropriate IOL calculation formula. Formula choice should be based on the specific characteristics of the operative eye, surgeon experience, ability to customize calculations, and the limitations of all formulas.