Myopic Shift 5 Years after Intraocular Lens Implantation in the Infant Aphakia Treatment Study

Abstract

Purpose To report the myopic shift at 5 years of age after cataract surgery with IOL implantation for infants enrolled in the Infant Aphakia Treatment Study. Methods Refractions were performed at 1 month and every 3 months postoperatively until age 4 and then at ages 4.25, 4.5 and 5 years. The change in refraction over time was estimated by linear mixed model analysis. Results IOL implantation was completed in 56 eyes; 43 were analyzed (median age = 2.4 mo, range = 1.0 – 6.8 mo). Exclusions included 11 patients with glaucoma, one patient with Stickler syndrome and one patient with an IOL exchange at 8 months postoperatively. The mean rate of change in a myopic direction from 1 month after cataract surgery up until age 1.5 years was 0.35 D/mo (95% CI = 0.29,0.40 D/mo); after age 1.5 years the mean rate of change in a myopic direction was 0.97 D/yr (95% CI = 0.66, 1.28 D/yr). The mean refractive change at age 5 years for children 1 month of age at surgery was 8.97 D (95% CI, 7.25, 10.68 D) and for children 6 months of age at surgery was 7.22 D (95% CI, 5.54, 8.91 D). The mean refractive error at age 5 years was −2.53 D (95% CI, −4.05, −1.02) Conclusion After IOL implantation during infancy, the rate of myopic shift occurs most rapidly during the first one and one-half years of life. Myopic shift varies significantly amongst patients. If the goal is emmetropia at age 5 years, then the immediate postoperative hypermetropic targets should be +10.5D at 4 to 6 weeks and 8.50 D from 7 weeks to 6 months. However, even using these targets it is likely that many children with require additional refractive correction given the high variability of refractive outcomes.

Anisometropia at Age 5 Years After Unilateral Intraocular Lens Implantation During Infancy in the Infant Aphakia Treatment Study

“…A final factor to consider in excessive myopic shift and resultant myopia is the development of glaucoma which can result in increased axial length and myopic shift in young eyes 30–31 In this series, 9 of 51 (18%) eyes were diagnosed with glaucoma (two eyes with glaucoma were excluded because they had an IOL exchange) Eyes with glaucoma did have significantly more anisometropia with a median of −8.25 D vs. −2.75 D in the non-glaucomatous eyes. Eyes with glaucoma were more likely to have myopic anisometropia of ≥5D (78% vs. 36% in non-glaucomatous eyes) suggesting a role for glaucoma in at least some patients with excessive myopic shift.…”

Re: Weakley et al.: Myopic shift 5 years after intraocular lens implantation in the infant aphakia treatment study (Ophthalmology. 2017;124:822-827)

“…This report did not identify any baseline characteristic to affect the rate of change of refractive error in regression analysis. 1 Perhaps a factor may be identified, as done by previous studies, if such comparisons are made. 1,4 Another noteworthy observation in this study was a faster myopic shift noted by the authors until 1.5 years of age, which decreased further up to 5 years of age.…”

“…1 Perhaps a factor may be identified, as done by previous studies, if such comparisons are made. 1,4 Another noteworthy observation in this study was a faster myopic shift noted by the authors until 1.5 years of age, which decreased further up to 5 years of age. 1 Similar results have been published previously by other studies, as cited in the current study, and are roughly also true for ocular growth overall.…”

“…TO THE EDITOR: In the study by Weakley et al, 1 the authors evaluated the myopic shift occurring after surgery in children with uniocular congenital cataract enrolled in the Infant Aphakia Treatment Study (IATS). 1 The authors commented on eyes implanted with an intraocular lens (IOL), while excluding eyes that had been left aphakic and rehabilitated with contact lens only.…”

“…During the intervention period of the study, the IOL power was calculated by aiming 8-diopter undercorrection in infants <48 days of age, and 6-diopter undercorrection for infants aged >48 days of age. 1 Thus, all eyes were aimed for postoperative hypermetropia and given spectacles depending on preset criteria, which is generally followed by pediatric cataract surgeons. Current research on axial myopia has revealed a possible role of "relative peripheral hyperopic defocus" in elongation of the eyeball.…”