Globe Axial Length Growth at Age 10.5 Years in the Infant Aphakia Treatment Study

Comparison of the axial growth with multifocal and monofocal intraocular lenses in unilateral pediatric cataract surgery

PURPOSE

To compare axial growth in pediatric cataract patients who underwent multifocal intraocular lens (IOL) implantation without anterior vitrectomy (AV) with that in pediatric patients who underwent monofocal IOL implantation with or without AV.

METHODS

Patients who had unilateral pediatric cataracts and underwent surgery at 3-6 years of age from June 6, 2019, to June 30, 2020, at our institution were prospectively analyzed. The patients were categorized into Group A: multifocal IOL implantation with optic capture in Berger's space without AV; Group B: monofocal IOL implantation with optic capture in Berger's space without AV; and Group C: bag-in-the-lens monofocal IOL implantation with AV. Groups A', B' and C' consisted of the fellow eyes from the respective groups. Axial growth and monthly growth rates were compared among the 3 treatment groups, as well as between the treated eyes and the fellow eyes.

RESULTS

Thirty-one, 23, and 14 children fulfilling the inclusion criteria, respectively, were included in the final analysis. There were no significant differences in patient age at the time of surgery or preoperative axial length (P > 0.05). After a mean follow-up of 35.57 ± 3.78 months, significant differences in the axial growth and the monthly growth rate were observed (P < 0.05), and Group A had the least axial elongation. Comparing treated eyes with fellow eyes, the amount and rate of axial growth were lower in Group A than in Group A' (P < 0.05), no significant differences were found in Group B (P > 0.05), and Group C had greater growth than did Group C' (P < 0.05).

CONCLUSIONS

The implanting multifocal intraocular lenses and maintenance of vitreous body integrity may be protective factors against excessive axial growth in pediatric cataract patients. Clinical trial registration (prospective study): chiCRT1900023155; 2019-05-14.

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.

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.

What we have learned from the Infant Aphakia Treatment Study: The 49th Annual Frank D. Costenbader Lecture

Unilateral congenital cataracts lead to deprivation amblyopia, which can be severe. Until the 1970s, they were believed to be always associated with poor visual outcomes. However, advances in our understanding of the plasticity of the infant brain and the development of better surgical techniques allowed good visual outcomes to be obtained in a few of these patients. The Infant Aphakia Treatment Study (IATS) was conducted to provide empirical evidence regarding the best type of optical correction to be used following surgical extraction of the cataract. Specifically, infants were randomly assigned to either be left aphakic and to wear contact lenses or an intraocular lens (IOL) was implanted and the residual refractive error was corrected with spectacles. The study found that good visual acuity and stereopsis could be achieved in some patients in both treatment groups. Early cataract surgery, consistent optical correction and part-time patching of the fellow eye are important elements needed to achieve good visual outcomes. However, excess patching of the fellow eye may interfere with the development of stereopsis. More adverse events occurred after IOL implantation, particularly visual axis opacification, compared with the infants who were left aphakic. Glaucoma-related adverse events occurred in 40% of eyes after a 10-year follow-up and were not associated with IOL implantation. Further research is needed to increase the percentage of children with unilateral congenital cataracts who achieve good visual outcomes.

Evolution and trends of childhood cataract research in the past 10 years: A scientometric analysis

Purpose

To present a panoramic review of childhood cataract knowledge networks, hotspots and trends.

Methods

The Web of Science Core Collection was used to retrieve the global literature on childhood cataract published between 2012 and 2021. Scientometric data were analyzed and visualized using VOSviewer and CiteSpace for metrics including publication count, citation count, country, journal, author, cited reference, subject category and their temporal trends.

Results

A total of 3395 analyzed publications showed an inconsistent annual increasing trend. The USA (n = 939) was the leading contributor among countries. The Journal of American Association for Pediatric Ophthalmology and Strabismus (n = 113) had the highest number of publications among journals. Eight clusters of author collaboration network including 183 authors were identified. Gene mutation, cataract surgery management, intraocular lens implantation complications, prevalence, and glaucoma were identified as the research hotspots. Pediatric cataract surgery, new mutations, artificial intelligence, and cerebrotendinous xanthomatosis were identified as frontier research topics. "Biochemistry and molecular biology", "neurosciences", and "radiology, nuclear medicine and medical imaging" had the highest betweenness centrality values (0.38, 0.32, and 0.22). Multidisciplinary (burst years: 2020 to 2021; strength = 4.32) had the greatest strength as of 2021.

Conclusions

Childhood cataract research intensely focuses on revealing the genetic background and pheno-spectrum of the diseases, innovating and/or optimizing surgical techniques, and preventing and treating postoperative complications. Artificial intelligence has shed light on the diagnosis and treatment of childhood cataracts. The advance in the research on molecular mechanisms of childhood cataracts depends on multidisciplinary cooperation.

Primary versus secondary intraocular lens implantation following removal of congenital/de al of congenital/developmental catar elopmental cataracts: outcomes after acts: outcomes after at least 4 years

BACKGROUND

The aim of this study is to evaluate the long-term outcomes of primary and secondary intraocular lens (IOL) implantation following removal of congenital/developmental cataracts.

METHODS

One hundred and forty-four patients aged under 16 years who were followed up between 2003 and 2021 were analyzed retrospectively. The long-term results of children who underwent surgery before 2 years of age for congenital or developmental cataracts and underwent secondary IOL implantation after 2 years of age and those who underwent cataract surgery with primary IOL implantation after 2 years of age were compared. Patients with traumatic, secondary cataracts and cataracts due to ocular anomalies were not included in the study.

RESULTS

We evaluated 64 patients (mean age 9.5 ± 4.5 years) with secondary IOL implantation and 80 patients (mean age 12.8 ± 4.1 years) with primary IOL implantation in the study. Distance and near best-corrected visual acuities were significantly better in the primary IOL group than the secondary IOL group (p < 0.001). Incidence of strabismus after primary IOL surgery was significantly lower and presence of binocular vision was more often than the secondary IOL group (p = 0.002). There was no significant difference between the two groups in terms of refraction and myopic shift (p = 0.242, p = 0.172, respectively). Mean refractive changes were significant in unilateral cases of secondary IOL group and primary IOL group (p = 0.013, p = 0.049, respectively) and myopic shift was also greater in both groups of unilateral cases than the fellow eyes (p = 0.023, p = 0.012, respectively).

DISCUSSION

Visual outcomes and binocular vision were better, and the incidence of strabismus was also much less in the primary IOL group.

The impact of pre-operative axial length on myopic shift 3 years after congenital and developmental cataract surgery and intraocular lens implantation

Purpose

To investigate the impact of the pre-operative axial length (AL) on myopic shift (MS) 3 years after primary intraocular lens (IOL) implantation in congenital/developmental cataract patients.

Methods

A retrospective study of patients who underwent congenital/developmental cataract surgery and primary IOL implantation at age 2-3 years at EENT Hospital was conducted. All patients were followed up regularly for at least 3 years after surgery. Refractive outcomes, including spherical equivalent (SE) and MS, were collected at each follow-up.

Results

Forty eyes from 40 patients were included. The mean age at surgery was 2.56 ± 0.57 years old, and the mean follow-up time was 3.05 ± 0.22 years. Patients were divided into two groups: Group 1 included 20 patients with longer pre-operative ALs (≥22 mm), and Group 2 included 20 patients with average pre-operative ALs (<22 mm). By the last follow-up, the MS was 2.13 (0.38, 2.63) D in Group 1 and 3.88 (2.85, 5.72) D in Group 2. The post-operative MS in Group 2 was statistically greater than that in Group 1 at 3 years after surgery (P < 0.001).

Conclusion

In congenital/developmental cataract patients who underwent cataract extraction and primary IOL implantation at age 2-3 years, eyes with longer pre-operative ALs had a slower MS than those with average pre-operative ALs 3 years after surgery. This finding could have implications for the target refraction decision in congenital/developmental cataract surgery.

A comparative analysis of myopia development in children with bilateral and unilateral pseudophakia

After the extraction of congenital cataract in infancy, postoperative refraction changes differently in patients with bilateral and unilateral pseudophakia. Purpose: to compare myopia development in children with bilateral and unilateral pseudophakia. Material and methods. We examined 33 children (63 eyes) with bilateral and 21 children with unilateral pseudophakia for long-term results of congenital cataract extraction performed in their infancy, The evaluated parameters included the incidence and degree of myopia, refraction, general postsurgical astigmatism, and axial length of the eye. Refraction was measured by Nidek ARK-530A (Japan). The axial length was measured by ultrasound B-scan (Voluson E8, GE) or by optical biometry (AL-Scan, Nidek). Results. In bilateral pseudophakia, high myopia was detected if astigmatism was more than 3.25 D or oblique. In the latter case, the eyeball showed a greater growth as compared to with-the-rule astigmatism (4.67 mm and 3.26 mm, respectively; p < 0.05). With incomplete correction of astigmatism in the case of bilateral pseudophakia, myopia progressed to a high degree in nearly half of the cases (48.1 %), and a greater growth of the eye was detected compared with complete correction (4.45 mm and 3.42 mm respectively; p > 0.05). The type and degree of astigmatism did not affect the development and progression of myopia in unilateral pseudophakia. Conclusion. The effect of undercorrected astigmatic defocus on the development and progression of myopia in bilateral pseudophakia is apparently associated with a equivalent visual load on both eyes, while this load is significantly reduced in unilateral pseudophakia so that it fails to affect the development of myopia in such cases.

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.

Vergence Formula for Estimating the Refractive Status of Aphakic Eyes in Pediatric Patients

Clinical Relevance

A vergence formula may provide a simple and reliable calculation of the refractive status of aphakic eyes.

Background

Measuring the refractive error of pediatric eyes with aphakia is difficult. This study investigated the accuracy and applicability of a vergence formula for estimating the refractive status of such eyes.

Methods

A retrospective review of the medical records, created between January 2016 and December 2018, of pediatric patients with aphakia was conducted. A vergence formula, based on axial length, was used to calculate the refractive status of the aphakic eyes. The refractive values determined using retinoscopy, an automatic refractometer, and the vergence formula were compared.

Results

A total of 72 eyes (47 patients) were analyzed. The spherical equivalents of the refractive errors (mean ± standard deviation) of the eyes were determined using retinoscopy (13.01 ± 3.27 D), automatic refractometry (12.90 ± 3.23 D), and the vergence formula (12.70 ± 3.4 D). The correlation coefficient between retinoscopy values determined using retinoscopy and the vergence formula, automatic refractometry and the vergence formula, and retinoscopy and automatic refractometry were 0.968, 0.987, and 0.979, respectively. The Bland-Altman consistency analysis revealed that the mean differences in the spherical equivalent values between retinoscopy and automatic refractometry, retinoscopy and the vergence formula, and automatic refractometry and the vergence formula were 0.11 D, 0.31 D, and 0.21 D, respectively, with 95% limits of agreement of−1.20 to 1.41 D,−1.37 to 2.00 D, and−0.90 to 1.31 D, respectively.

Conclusion

The vergence formula was effective for evaluating the refractive status of aphakic eyes in pediatric patients.

Outcomes of secondary intraocular lens implantation in the Infant Aphakia Treatment Study

PURPOSE

To report outcomes of secondary intraocular lens (IOL) implantation in the Infant Aphakia Treatment Study (IATS).

SETTING

Multicenter clinical practice.

DESIGN

Secondary analysis of patients enrolled in a randomized clinical trial.

METHODS

Details regarding all secondary IOL surgeries conducted in children enrolled in the IATS were compiled. Visual outcomes, refractive outcomes, and adverse events at the age of 10½ years were evaluated. Comparisons were made with eyes that remained aphakic and with eyes randomized to primary IOL placement.

RESULTS

The study included 114 infants, 57 in the aphakic group and 57 in the primary IOL group; 55 of 57 patients randomized to aphakia with contact lens correction were seen for the 10½-year study visit; 24 (44%) of 55 eyes had secondary IOL surgery. Median age at IOL surgery was 5.4 years (range 1.7 to 10.3 years). Mean absolute prediction error was 1.00 ± 0.70 diopters (D). At age 10½ years, the median logarithm of the minimum angle of resolution visual acuity (VA) was 0.9 (range 0.2 to 1.7), similar to VA in the 31 eyes still aphakic (0.8, range 0.1 to 2.9); the number of eyes with stable or improved VA scores between the 4½-year and 10½-year study visits was also similar (78% secondary IOL eyes; 84% aphakic eyes). For eyes undergoing IOL implantation after the 4½-year study visit (n = 22), the mean refraction at age 10½ years was -3.20 ± 2.70 D (range -9.90 to 1.10 D), compared with -5.50 ± 6.60 D (n = 53, range -26.50 to 3.00 D) in eyes with primary IOL (P = .03).

CONCLUSIONS

Delayed IOL implantation allows a more predictable refractive outcome at age 10½ years, although the range of refractive error is still large.