Secondary intraocular lens implantation in children
Reviewed by Jonathan Chan

This is a retrospective study of the medical records of children under the age of 16 who underwent secondary lens implantation for aphakic corrections after previous congenital cataract surgery over a period between January 2000 and December 2010. The study analysed the outcome of refraction, prediction error (PE) and factors affecting PE in children with aphakia were evaluated in this study. In total 174 eyes of 104 children between the age of 6.08±3.75 years were analysed. The mean value of PE was 1.6 dioptres (range -3.25 to 7.5D) and mean absolute PE was 2.15 (range 0-7.5D) at three months. The younger and uncooperative children had the keratometer readings measured under anaesthetic intraoperatively using a Nidek KM 500 handheld keratometer and the axial length was measured with a contact A-scan with OcuScanRxP. All intraocular lens power calculations were performed using a Sanders-Retzlaff-Kraff (SRK) II formula. It was found that the absolute PE was statistically significant between eyes with the intraocular lens (IOL) implantations calculated with the IOL master (1.8±1.40D) versus IOL calculation under anaesthesia with contact method (2.43±1.83D), p=0.01. Multiple regression analysis showed there is an inverse relationship between a secondary intraocular lens implantation and mean absolute PE (p=0.01). The surgical technique was standardised to a superior scleral tunnel technique and a polymethylmethacrylate (PMMA) IOL was used or alternatively clear corneal incisions for acrylic foldable (three piece) IOLs were inserted. A paracentesis site was situated at 10 and 2 o’clock positions for the removal of the re-proliferative lens material. The authors concluded that SRK II formula intraocular power calculations with sulcus placement gives more favourable refractive outcomes for the placement of intraocular lens implants. Although the age base refraction was targeted, a significant PE may be expected from the calculation.

Refractive outcome and prediction error following secondary intraocular lens implantation in children: a decade-long analysis.
Shenoy BH, Mittal V, Gupta A, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013:97:1516-9.