NEW METHOD TO CALCULATE THE INTRAOCULAR LENS POWER IN CONGENITAL CATARACTS

To propose a new strategy calculating the intraocular lens power and reducing myopic refractive errors in congenital cataracts.

The choice of intraocular lens power in congenital cataracts is a difficult but crucial stage in the visual development of these children. At present, surgeons under correct the intraocular lens power at implantation of pediatric cataracts to anticipate for the ocular growth. However, actual under correction strategies are imprecise and lead to myopic refractive errors.

Data from children with congenital cataracts implanted between 2005 and 2020 at the University Hospital of Marseille were retrospectively collected. A logarithmic regression model was used to predict the ocular growth from implantation to the age of 15. The predicted ocular growth in millimeters was converted into diopters and used as a target refraction to calculate a theoretical intraocular lens aiming for emmetropia at the age of 15. A refractive error with the theoretical lens was estimated by subtracting the spherical equivalent at the last follow-up and the difference between target refractions of the implanted lens and the theoretical lens.

A total of 35 eyes from 26 children were analyzed. At the last follow-up, the median age was 10 years old, and the median spherical equivalent was -1.88 diopters (interquartile range: -3.81 to -0.75). The median theoretical refractive error with the logarithmic model was 0.18 diopters (-1.11 to 1.42).

The estimated refractive error with the logarithmic model is close to emmetropia at the last follow-up. This new method could help reduce myopic refractive errors in pediatric cataracts.