[Ocular axial length and refractive changes in pediatric pseudophakia]

To evaluate the ocular axial length and refractive changes that occured in children who had cataract extraction with intraocular lens implantation and to investigate the factors that influenced the pseudophakic refraction.

A review of 12 eyes in 10 children (mean age 7.16 years, range 3.83 to 10.16 years) who had cataract extraction with intraocular lens implantation was undertaken. Patients were followed for an average of 35.8 months. The preoperative and the last postoperative axial length and corneal curvature (K readings) in both operated and unoperated eyes were measured. The distance from the vertex of the cornea to the anterior vertex of intraocular lens (AVpc) was measured in the final follw-up. The initial (in two weeks) and the last refractive status of pseudophakia were examined. Overall age at surgery averaged 7.16 years (range 3.83 to 10.16 years), with followed up of 35.8 months.

In the 12 operated eyes, the mean axial growth was 0.39 mm, whereas in the other eight unoperated eyes it was 0.66 mm. Though the axial length of both eyes increased significantly after surgery (P < 0.05), there was no significant difference in the postoperative increase of axial length between the two groups(P > 0.05). In K readings, there was no significant difference between the operated and unoperated eyes before surgery and in the last follow-up respectively. There was no significant difference between the preoperation and the last follow-up in the operated and the unoperated eyes respectively. The average calculated AVpc (AVpc2) was 4.66 30 mm, but the average objective AVpc (AVpc1) measured with ultrasonic biometry was 3.83 mm. The average difference between them was 0.8320 mm and was significant (P < 0.01). According to SRK formula, using preoperative and the last postoperative axial length and corneal curvature to predict refractive changes, the myopic shift was -1.53 D, but the average objective refractive difference between the last and initial examination after surgery was -3.86 D. The average difference between the predicted and actual postoperative refractive changes was significant (P < 0.05).

Our study suggests that there may be no effect on ocular growth in children (3 to 10 years) followed cataract extraction and intraocular lens implantation. Increasing of axial length and moving forward of intraocular lens induced by complication may result in myopic shift in pseudophakia of children. Slightly undercorrected eyes with intraocular lens in children after cataract extraction will gradually move to emmetropia or moderate myopia in adulthood.