Intraocular lenses in children: changes in axial length, corneal curvature, and refraction

Aim-To assess changes in axial length, corneal curvature, and refraction in paediatric pseudophakia. Methods-35 eyes of 24 patients with congenital or developmental lens opacit ies underwent extracapsular cataract extraction and posterior chamber intra ocular lens implantation. Serial measurements were made of axial length, co rneal curvature, objective retraction, and visual acuity. Results-For patients with congenital cataracts (onset <1 year age) the mean age at surgery was 24 weeks. Over the mean follow up period of 2.7 years, the mean increase in axial length of 3.41 mm was not significantly differen t from the value of an expected mean growth of 3.44 mm (paired t test, p=0. 97) after correction for gestational age. In the developmental cataract gro up (onset >1 year of age) the mean age at surgery was 6.4 years with a mean follow up of 2.86 years. This group showed a mean growth in axial length o f 0.36 mm that was not significantly different from an expected value of 0. 47 mm (paired t test, p=0.63). The mean preoperative keratometry was 47.78 D in the congenital group and 44.35 D in the developmental group. At final follow up the mean keratometry in the congenital. group was 46.15 D and in the developmental group it was 43.63 D. In eyes followed for at least 2 yea rs, there was an observed myopic shift by 24 months postoperatively of 3.26 D in the congenital cases (n=10) and 0.96 D in the developmental cases (n= 18). Conclusion-The pattern of axial elongation and corneal Aattening was simila r in the congenital and developmental groups to that observed in normal eye s. No significant retardation or acceleration of axial growth was found in the eyes implanted with IOLs compared with normal eyes. A myopic shift was seen particularly in eyes operated on at 4-8 weeks of age and it is recomme nded that these eyes are made 6 D hypermetropic initially with the residual refractive error being corrected with spectacles.