[Predictability of intraocular lens power calculation in the treatment of cataracts in children].

PURPOSE

To evaluate the predictability of intraocular lens (IOL) power calculation taking in account the changing refraction in children operated on for congenital cataract with primary posterior chamber IOL implantation.

METHODS

We compared the predicted (PR) and objective (OR) refraction in 89 eyes of 70 children (1 month to 16 years) (1989 to 1995) at 1 month and 3 years after cataract surgery. The eyes were divided in 4 groups. Group A: < 1 year; Group B: 1 year to 3 years; Group C: 3 years to 5 years; Group D: > 5 years. For patients operated on before 3 years of age, we used a modified SRK II formula with the aim of achieving an undercorrection (85% of SRK II value in group A, 95% of SRK II value in group B).

RESULTS

The average objective refraction (OR) and the average error (AE = (OR)-(PR)) were respectively at 1 month and 3 years after surgery for the Group A: (OR: +3.5 D/-1.8 D) (AE: -1 D/-6.4 D); Group B: (OR: +1.3 D/-1.3 D) (AE: -0.9 D/-3.6 D); Group C: (OR: -0.2 D/-1.4 D) (AE: +0.1 D/-1.1 D); Group D (OR: +0.1 D/-1 D) (AE: +0.8 D/-0.4 D).

CONCLUSION

At 1 month after surgery, the predictability of IOL power calculation appears accurate with a refractive error between -1 D and +0.8 D in the four groups. However we noted an increase in refractive error at 3 years with a progressive myopic shift, specially in the eyes operated on before 1 year of life which had the greatest change in axial length.