Long-term results after pars plana lensectomy for congenital cataract surgery

Purpose: Several techniques of cataract surgery in young children must take into account the high rate of posterior capsule opacification (PCO) on one hand, and the incomplete growth of the eye in infants on the other hand which may result in a high myopic shift if lens implantation is performed too early. As a consequence, generally no lens is implanted in children younger than 1.5-2 years of age, and postoperative aphakia is corrected by contact lenses or spectacle glasses. In contrast, primary posterior chamber lens (PCIOL) implantation is the method of choice in older children. Surgery may be performed via a limbal or pars plana approach. The present paper deals with our experience and long-term results of pars plana lensectomy in infants particularly regarding best corrected visual acuity (BCVA), PCO rate, evolution of refractive error changes and development of binocular functions. Patients and methods: Between 1994 and 2002 pars plana lensectomy with anterior and posterior capsulotomy and anterior vitrectomy was performed in 11 children (mean age 2.3 months at time of surgery) with bilateral congenital cataracts (22 eyes) and in 4 patients between 1 month and 3.5 years of age with unilateral cataracts. Correction of aphakia was performed with contact lenses or spectacle glasses and all patients underwent intensive orthoptic examinations postoperatively. In 7 eyes secondary PCIOL implantation was performed between 3.5 and 6 years of age. Results: In all eyes a clear visual axis could be achieved after surgery. Mean best corrected visual acuity increased from 0.3 at an age of 4 years to 0.5 (range 0.16-0.8) at 7 years. Elschnig pearl PCO which required surgical removement occurred in 4 eyes between 1.5 and 3.5 months postoperatively. Other complications with the exception of one case with secondary glaucoma were not observed. Binocular functions could be detected in 5 patients and were lacking in 3 children but could not be assessed in the remaining patients due to their low age. Patients with unilateral cataracts achieved mean BCVA of 0.1 after surgery. Binocular functions were detected only in one patient. Mean postoperative refraction of aphakic eyes decreased from + 25 dpts at an age of few months to + 20 dpts with 12 months, to + 17 dpts with 3 years, and stabilized at + 16 and + 17 dpts between 4 to7 years of age. Conclusions: In the present study we could show that pars plana lensectomy is a save and efficacious method of cataract surgery in children younger than 2 years of age, in whom primary PCIOL implantation would lead to a significant myopic shift due to the incomplete axial growth of the infant's eye. With this technique lensectomy with anterior and posterior capsulotomy simultaneously with anterior vitrectomy may be performed relatively easily using the same small incision through the pars plana/ pars plicata. Secondary PCIOL implantation -usually with good refractive results -may be taken into consideration later when the axial growth of the eye is completed.