Calculating accurate IOL power in infants

Intraocular lens (IOL) power, following primary lens implantation in infants, can be calculated reasonably accurately using current formulae, according to a report published online (December 2006) ahead of print in the British Journal of Ophthalmology.

Jane Ashworth and colleagues from the Manchester Royal Eye Hospital, UK, conducted a retrospective case review of 25 patients (eight with bilateral cataracts and 17 with unilateral) who underwent cataract surgery with primary IOL implantation at less then 12 months of age. The outcomes measured were actual early-postoperative refraction, lens power calculation error, myopic shift and refractive outcome.

In 83% of cases, actual postoperative refraction was within 2 D of target refraction. The researchers found that lens power calculation error did not depend on axial length, age at surgery or target refraction. The mean myopic shift was 5.43±3.7 D in the first 12 months following surgery, but was significantly greater where surgery was performed at less than 10 weeks of age.

The researchers found that, using current formulae, IOL power can be calculated with reasonable accuracy.