Prediction error after pediatric cataract surgery with intraocular lens implantation: Contact versus immersion A-scan biometry

PURPOSE: To evaluate the accuracy of pediatric intraocular lens (IOL) calculations performed using contact and immersion A-scan biometry. SETTING: Storm Eye Institute, Charleston, South Carolina, USA. DESIGN: Evaluation of diagnostic test or technology. METHODS: Data from a prospective study of pediatric eyes that had in-the-bag implantation of an AcrySof SN6OWF IOL and had refraction results available from 14 days to 3 months postoperatively were retrospectively analyzed. The contact and immersion A-scan biometry techniques were performed in each eye and compared. RESULTS: The mean age at surgery of the 22 patients (22 eyes) was 4.8 years +/- 4.1 (SD). The mean prediction error was + 0.4 +/- 0.7 diopter (D) in the contact group and -0.4 +/- 0.8 D in the immersion group (P < .001) and the mean absolute prediction error, 0.7 +/- 0.4 D and 0.7 +/- 0.6 D, respectively (P = .694). The absolute prediction error was less than 0.5 D in 5 eyes (23%) using the contact technique and 11 eyes (50%) using the immersion technique. The mean postoperative spherical equivalent was +2.9 +/- 2.5 D, which was significantly different from the mean predicted refraction for contact A-scan (3.3 +/- 2.8 D; P = .010) but not immersion A-scan (2.5 +/- 2.5 D; P = .065). CONCLUSIONS: There was a significant difference in prediction error between postoperative refractive results obtained with contact biometry and immersion A-scan biometry in children. Based on the results, the immersion A-scan technique is recommended for pediatric IOL power calculation.