Refractive growth variability in the Infant Aphakia Treatment Study

Ten-year outcomes of congenital cataract surgery performed within the first six months of life

PURPOSE

To investigate the long-term outcomes of congenital cataract surgery performed within the first 6 months of life.

SETTING

11 ophthalmic surgical sites in Japan.

DESIGN

Retrospective chart review.

METHODS

Medical charts were retrospectively reviewed for 216 eyes of 121 patients. The age at surgery was 2.9 ± 1.7 months, with follow-up duration 13.0 ± 2.3 years. The cohort consisted of 83 cases with bilateral aphakia, 12 with bilateral pseudophakia, 20 with unilateral aphakia, and 6 with unilateral pseudophakia.

RESULTS

Surgical intervention within the critical period of visual system development (10 weeks for bilateral and 6 weeks for unilateral cases) led to significantly better final visual acuity than surgery conducted after this time frame. The incidence of secondary glaucoma was similar between groups while the occurrence of visual axis opacification was more frequent with earlier surgery. A forward stepwise multiple regression analysis revealed that the final visual acuity was significantly associated with laterality of cataract (better outcomes in bilateral cases), phakic status (with pseudophakia outperforming aphakia), presence of systemic and ocular comorbidities, and development of secondary glaucoma. Secondary glaucoma was significantly more prevalent in aphakic eyes than pseudophakic eyes.

CONCLUSIONS

In patients with genuine congenital cataract, surgery within the critical period of visual development results in better final visual acuity, albeit with an increased risk of visual axis opacification. The use of IOL with sophisticated surgical techniques shows promise even in congenital cataract surgery.

Association Between Preoperative Ocular Parameters and Myopic Shift in Children Undergoing Primary Intraocular Lens Implantation

Purpose

To evaluate the association between preoperative ocular parameters and myopic shift following primary intraocular lens (IOL) implantation in pediatric cataracts.

Methods

Eyes from pediatric patients undergoing bilateral cataract surgery with primary IOL implantation were included. Eyes were grouped by age at surgery and subdivided into three axial length (AL) subgroups and three keratometry subgroups. Mixed-effects linear regression was utilized to assess the trend in myopic shift among subgroups. Multivariable analysis was performed to determine factors associated with myopic shift.

Results

A total of 222 eyes were included. The median age at surgery was 4.36 years (interquartile range [IQR], 3.16-6.00 years) and the median follow-up was 4.18 years (IQR, 3.48-4.64 years). As preoperative AL increased, a decreased trend was observed in myopic shift and rate of myopic shift (P = 0.008 and P = 0.003, respectively, in the 4 to <6 years old group; P = 0.002 and P < 0.001, respectively, in the ≥6 years old group). Greater myopic shift and rate of myopic shift were associated with younger age at surgery (P = 0.008 and P = 0.008, respectively). Both myopic shift and rate of myopic shift were negatively associated with AL.

Conclusions

Age at surgery and preoperative AL were associated with myopic shift in pediatric cataracts following primary IOL implantation. Adjusting the target refraction based on preoperative AL could potentially improve patients' long-term refractive outcome.

Translational Relevance

This study may help to guide the selection of postoperative target refraction according to age at surgery and preoperative ocular parameters for pediatric cataracts.

10-Year Outcomes of Pediatric Cataract Surgery with Foldable Intraocular Lens Implantation and Posterior Continuous Curvilinear Capsulorhexis

INTRODUCTION

We investigated the long-term outcomes of pediatric cataract surgeries performed with modern surgical techniques involving in-the-bag implantation of a foldable intraocular lens (IOL).

METHODS

Data were retrospectively collected from 42 eyes in 30 patients who underwent surgery at 6 years and younger (average 2.5 ± 2.3 years) and were followed up for an average of 12.2 ± 2.4 years (10-17 years). Surgical procedures included anterior continuous curvilinear capsulorhexis (CCC), lens removal, posterior CCC, anterior vitrectomy, and in-the-bag IOL implantation. There were 18 unilateral (2.7 ± 2.3 years) and 12 bilateral cases (2.3 ± 2.3 years), with no significant age difference between groups (p = 0.462).

RESULTS

The mean best-corrected visual acuity (BCVA) at the final visit was 0.453 ± 0.488 (logMAR), correlating significantly with the age at surgery (r = -0.307, p = 0.048). The unilateral group had a worse BCVA (0.658 ± 0.615) than the bilateral group (0.298 ± 0.294) (p < 0.001). On average, eyes showed a myopic shift of -6.0 ± 6.3D, which significantly correlated with surgical age (r = 0.402, p = 0.008). While the myopic shift was -8.2 ± 6.1 D in the unilateral group and -4.9 ± 6.4 D in the bilateral group, the net shift for unilateral cases (comparing pseudophakic and fellow eyes) was -4.8 D. Three eyes (7.1%) exhibited suspected glaucoma (increased intraocular pressure), but no glaucoma or other severe complications were noted. IOL exchange surgery was necessary in two eyes (4.8%) due to pronounced myopic drift and significant IOL decentration. Three eyes (7.1%) required surgery for significant visual axis opacification.

CONCLUSIONS

Contemporary surgical strategies appear to yield promising long-term outcomes in patients with infantile cataracts.

Comparison of baseline biometry measures in eyes with pediatric cataract to age-matched controls

PURPOSE

To compare baseline biometry measurements in eyes with pediatric cataract versus age-matched controls METHODS: This is a cross-sectional study conducted at a tertiary care hospital that included two arms-prospective arm to collect data from normal eyes and retrospective arm for eyes with pediatric cataract. In the prospective arm, biometry measurements were obtained in healthy children aged 0 to 10 years. Children under the age of four had measurements under anesthesia for an unrelated procedure, while older children had in-office measurements using optical biometry. For comparison, biometric data was collected in children with pediatric cataract through record review. One eye of each patient was randomly selected. Axial length (AL) and keratometry (K) were compared by age and laterality. The medians were compared using Wilcoxon rank-sum tests and variances using Levene's test.

RESULTS

There were 100 eyes in each arm, 10 eyes in each age bin of 1-year interval. There was more variability in baseline biometry in eyes with pediatric cataract and a trend for longer AL and steeper K in cataract eyes than aged-matched controls. The difference in AL means was significant in age group 2-4 years, and variances were significant across all age groups (p=0.018). Unilateral cataracts (n=49) showed a trend toward greater variability in biometry than bilateral cataracts, but this did not reach statistical significance.

CONCLUSION

Baseline biometry measures are more variable in eyes with pediatric cataract compared to age-matched controls with a trend toward longer AL and steeper K.

Soft contact lens options in the management of pediatric aphakia - A quantitative and qualitative assessment

BACKGROUND

The main contact lens for pediatric aphakia has historically been a silicone elastomer lens (Silsoft SuperPlus). Due to supply chain disruption, many aphakic children required an alternative lens. We performed quantitative and qualitative comparisons between Silsoft SuperPlus and alternative aphakic soft contacts.

METHOD

Sixty-nine aphakic eyes of 49 patients wearing Silsoft SuperPlus lenses underwent the refitting process into an alternative soft contact. Data collected included lens parameters, visual acuity, keratometry, horizontal visible iris diameter, and over-refraction. A 6-question survey assessing the patients'/guardians' experience with Silsoft SuperPlus versus the alternative lens was conducted at initial fit and 1-3 months post-fit.

RESULTS

Twenty-four patients (49 %), 4(8 %), and 1(2 %) were refit into Flexlens Definitive 74, Biofinity XR, and Intelliwave Pro Toric lenses, respectively. Sixteen patients (34 %) remained in Silsoft SuperPlus due to personal lens surplus or inability to handle the new lens while 2(4 %) opted for glasses. Silsoft SuperPlus was typically successful in eyes with average keratometry (AveK) 7.4-7.6 mm. Flexlens Definitive 74 required a base curve 0.4 mm steeper than the AveK. Patients'/guardias' reported a trend toward greater comfort with handling Silsoft SuperPlus, however, patients experienced less adverse side effects with the alternative soft contact lenses.

CONCLUSIONS

Flexlens Definitive 74 was an adequate alternative to Silsoft SuperPlus in aphakic children, however lens parameters must be steepened. Keratometry streamlined the contact lens fitting process. Alternative soft lenses are a cost-effective alternative to Silsoft contact lenses.

The contribution of intraocular lens calculation accuracy to the refractive error predicted at 10 years in the Infant Aphakia Treatment Study

PURPOSE

To determine the relative contribution of intraocular lens (IOL) calculation accuracy and ocular growth variability to the long-term refractive error predicted following pediatric cataract surgery.

METHODS

Pseudophakic eyes of children enrolled in the Infant Aphakia Treatment Study (IATS) were included in this study. Initial absolute prediction error (APE) and 10-year APE were calculated using the initial biometry, IOL parameters, postoperative refractions, and mean rate of refractive growth. The cohort was divided into children with a low-initial APE (≤1.0 D) and a high-initial APE ( >1.0 D). The 10-year APE was compared between the two groups using the Mann-Whitney U test. Linear regression was used to estimate the variability in prediction error explained by the initial IOL calculation accuracy.

RESULTS

Forty-two children with IOL placement in infancy were included. Seventeen eyes had a low initial APE, and 25 eyes had a high initial APE. There was no significant difference in APE 10 years following surgery between individuals with a low initial APE (median, 2.67 D; IQR, 1.61-4.12 D) and a high initial APE (median, 3.45 D; IQR, 1.64-5.10 D) (P = 0.7). Initial prediction error could explain 12% of the variability in the prediction error 10 years following surgery.

CONCLUSIONS

IOL calculation accuracy contributed minimally to the refractive error predicted 10 years after cataract surgery in the setting of high variability in the rate of refractive growth.

Refractive Growth of the Crystalline Lens in the Infant Aphakia Treatment Study

Objective

To compare the rate of refractive growth (RRG3) of the crystalline lens ("lens") versus the eye excluding the lens ("globe") for the fellow, noncataractous eyes of participants in the Infant Aphakia Treatment Study.

Design

Retrospective cohort study.

Subjects

A total of 114 children who had unilateral cataract surgery as infants were recruited. Biometric and refraction data were obtained from the normal eyes at surgery and at 1, 5, and 10 years. Subjects were included if complete data (axial length [AL], corneal power, and refraction) were available at surgery and at 10 years of age.

Methods

At surgery and at 1, 5, and 10 years, AL, corneal power, and cycloplegic refraction were measured in the normal eyes. For each eye, the RRG3 was defined by linear regression of refraction at the intraocular lens (IOL) plane against log₁₀ (age + 0.6 years). The RRG3 for the globe was based on IOL power for emmetropia; the RRG3 for the lens was based on IOL power calculated to give the observed refractions. Intraocular lens powers were calculated with the Holladay 1 formula. The means were compared with a paired 2-tailed t test, and linear regression was used to look for a correlation between RRG3 of the lens globe.

Main Outcome Measures

The RRG3 of the lens and globe.

Results

Complete data were available for 107 normal eyes. The mean RRG3 of the lenses was -12.0 ± 2.5 diopters (D) and the mean RRG3 of the globes was -14.1 ± 2.7 D (P < 0.001). The RRG3 of the lens correlated with the RRG3 of the globe (R ²  = 0.25, P < 0.001).

Conclusions

The RRG3 was 2 D more negative in globes compared with lenses in normal eyes. Globes with a greater rate of growth tended to have lenses with a greater rate of growth.

Effective lens position and pseudophakic refraction prediction error at 10½ years of age in the Infant Aphakia Treatment Study

BACKGROUND

The refraction prediction error (PE) for infants with intraocular lens (IOL) implantation is large, possibly related to an effective lens position (ELP) that is different than in adult eyes. If these eyes still have nonadult ELPs as they age, this could result in persistently large PE. We aimed to determine whether ELP or biometry at age 10½ years correlated with PE in children enrolled in the Infant Aphakia Treatment Study (IATS).

METHODS

We compared the measured refraction of eyes randomized to primary IOL implantation to the "predicted refraction" calculated by the Holladay 1 formula, based on biometry at age 10½ years. Eyes with incomplete data or IOL exchange were excluded. The PE (predicted - measured refraction) and absolute PE were calculated. Measured anterior chamber depth (ACD) was used to assess the effect of ELP on PE. Multiple regression analysis was performed on absolute PE versus axial length, corneal power, rate of refractive growth, refractive error, and best-corrected visual acuity.

RESULTS

Forty-three eyes were included. The PE was 0.63 ± 1.68 D; median absolute PE, 0.85 D (IQR, 1.83 D). The median absolute PE was greater when the measured ACD was used to calculate predicted refraction instead of the standard A-constant (1.88 D [IQR, 1.72] D vs 0.85 D [IQR, 1.83], resp. [P = 0.03]). Absolute PE was not significantly correlated with any other parameter.

CONCLUSIONS

Variations in ELP did not contribute significantly to PE 10 years after infant cataract surgery.

Deviations From Age-Adjusted Normative Biometry Measures in Children Undergoing Cataract Surgery: Implications for Postoperative Target Refraction and IOL Power Selection

PURPOSE

To evaluate whether pediatric eyes that deviate from age-adjusted normative biometry parameters predict variation in myopic shift after cataract surgery.

METHODS

This is a single institution longitudinal cohort study combining prospectively collected biometry data from normal eyes of children <10 years old with biometry data from eyes undergoing cataract surgery. Refractive data from patients with a minimum of 5 visits over ≥5 years of follow-up were used to calculate myopic shift and rate of refractive growth. Cataractous eyes that deviated from the middle quartiles of the age-adjusted normative values for axial length and keratometry were studied for variation in myopic shift and rate of refractive growth to 5 years and last follow-up visit. Multivariable analysis was performed to determine the association between myopic shift and rate of refractive growth and factors of age, sex, laterality, keratometry, axial length, intraocular lens power, and follow-up length.

RESULTS

Normative values were derived from 100 eyes; there were 162 eyes in the cataract group with a median follow-up of 9.6 years (interquartile range: 7.3-12.2 years). The mean myopic shift ranged from 5.5 D (interquartile range: 6.3-3.5 D) for 0- to 2-year-olds to 1.0 D (interquartile range: 1.5-0.6 D) for 8- to 10-year-olds. Multivariable analysis showed that more myopic shift was associated with younger age (P < .001), lower keratometry (P = .01), and male gender (P = .027); greater rate of refractive growth was only associated with lower keratometry measures (P = .001).

CONCLUSIONS

Age-based tables for intraocular lens power selection are useful, and modest adjustments can be considered for eyes with lower keratometry values than expected for age.

The accuracy of intraocular lens calculation varies by age in the Infant Aphakia Treatment Study

Refraction predictions from intraocular lens (IOL) calculation formulae are inaccurate in children. We sought to quantify the relationship between age and prediction error using a model derived from the biometry measurements of children enrolled in the Infant Aphakia Treatment Study (IATS) when they were ≤7 months of age. We calculated theoretical predicted refractions in diopters (D) using axial length, average keratometry, and IOL powers at each measurement time point using the Holladay 1 formula. We compared the predicted refraction to the actual refraction and calculated the absolute prediction error (APE). We found that the median APE was 1.60 D (IQR, 0.73-3.11 D) at a mean age (corrected for estimated gestational age) of 0.20 ± 0.14 years and decreased to 1.11 D (IQR, 0.42-2.20 D) at 10.60 ± 0.27 years. We analyzed the association of age with APE using linear mixed-effects models adjusting for axial length, average keratometry, and IOL power and found that as age doubled, APE decreased by 0.25 D (95% CI, 0.09-0.40 D). The accuracy of IOL calculations increases with age, independent of biometry measurements and IOL power.