Effect of age at time of cataract surgery on subsequent axial length growth in infant eyes

Myopic Shift over 5 Years after Pediatric Lensectomy with Primary Intraocular Lens Implantation

PURPOSE

To report the change in refractive error over 5 years after primary intraocular lens (IOL) placement by age at surgery and to identify factors associated with the change in refractive error after 5 years.

DESIGN

Prospective observational study at 61 pediatric eye care practices.

PARTICIPANTS

One hundred eighty-six eyes of 152 children undergoing primary IOL implantation before 13 years of age for nontraumatic cataract.

INTERVENTIONS

Cataract surgery with primary IOL placement.

MAIN OUTCOME MEASURES

Five-year change in refractive error (spherical equivalent) by age at surgery and by immediate postoperative myopia versus emmetropia or hyperopia.

RESULTS

Mean spherical equivalent myopic shift was -5.99 diopters (D; 95% confidence interval [CI], -7.64 to -4.34 D) when surgery was performed at 0 to younger than 1 year of age (n = 13), -3.53 D (-4.57 to -2.48 D) at 1 to younger than 2.5 years of age (n = 28), -1.91 D (-2.55 to -1.26 D) at 2.5 to younger than 4 years of age (n = 36), -2.04 D -2.60 to -1.49 D) at 4 to younger than 7 years of age (n = 60), and -0.83 D (-1.27 to -0.40 D) at 7 to younger than 13 years of age (n = 49; P < 0.01 for each comparison with the oldest group). Variability of myopic shift also decreased with increasing age (P < 0.01). In eyes of children 4 to younger than 13 years of age (small sample size precluded analysis of children younger than 4 years), significantly less mean change in refractive error was found over 5 years in eyes with myopia immediately after surgery (-0.69 D; 95% CI, -1.48 to 0.10 D; n = 27) than eyes with emmetropia or hyperopia immediately after surgery (-1.70 D; 95% CI, -2.10 to -1.31 D, n = 82; difference, -1.01 D [95% CI, -1.89 to -0.14 D]; P = 0.03).

CONCLUSIONS

In this large, prospective cohort study of children younger than 13 years undergoing cataract surgery with primary IOL placement, greater and more variable myopic shift was found in children undergoing surgery at a younger age. Our finding of less myopic shift over 5 years in eyes with unintended immediate postoperative myopia deserves further study to guide IOL power selection more accurately.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Visual axis opacification after pediatric cataract surgery - An analysis of morphology and etiology

PURPOSE

To investigate the morphological types and delineate the clinical and surgical variables associated with VAO in children undergoing pediatric cataract surgery.

METHODS

We included 33 eyes of 28 children who developed clinically significant visual axis opacification (VAO) after congenital or developmental cataract surgery. All eyes underwent a comprehensive examination under anesthesia followed by a membranectomy to clear the visual axis. We classified VAO into three subgroups: fibrotic, proliferative, and combined morphologies. We reviewed and analyzed the retrospective data and the findings during membranectomy to identify the etiological variables associated with various morphologies of VAO.

RESULTS

The median age at primary surgery was 7 (2-96) months. The median interval from primary surgery to the first documentation of VAO was 6 (1-22) months. Younger children developed VAO sooner than older children. VAO was fibrotic in 11 eyes (33%), proliferative in 18 eyes (54.5%), and combined in four eyes (12.12%). Most children with fibrotic VAO belonged to economically disadvantaged sections of society ( P = 0.04).

CONCLUSION

Lower age at primary surgery was the predominant risk factor for the development of VAO. Besides primary posterior capsulotomy and adequate anterior vitrectomy, a strict adherence to anti- inflammatory measures and follow up in necessary to prevent the occurrence of VAO. A close follow-up facilitates early detection and management, which can prevent the onset of visually impairing amblyopia.

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.

Longitudinal Changes of Axial Length and Associated Factors in Congenital Ectopia Lentis Patients

Purpose

To investigate the longitudinal changes and associated factors of axial length (AL) in congenital ectopia lentis (CEL) patients.

Methods

In this retrospective study, medical records of CEL patients were reviewed from January 2014 to December 2019 at the Zhongshan Ophthalmic (ZOC) in China. Patients were divided into the surgery group and the nonsurgery group. Data of refractive power, best-corrected visual acuity (BCVA), and intraocular pressure (IOP) as well as ocular biometrics including AL, corneal curvature, white-to-white (WTW), and central corneal thickness (CCT) were collected at baseline and each follow-up visit. Multiple linear regression was performed to assess the potential associated factors for axial length growth in congenital ectopia lentis patients.

Results

Compared with the nonsurgery group, the change rate of AL among children aged 3 to 6 years old was slower in the surgery group (0.443 ± 0.340 mm/year vs. 0.278 ± 0.227 mm/year, P < 0.05). However, no statistically significant difference for the change rate of AL was detected between the surgery group and the nonsurgery group (P > 0.05) among patients aged 7 years or older. For the surgery group, the results of the linear regression model showed that a higher change rate of AL was associated with younger age (older age: β = −0.009, 95% CI: −0.014 to −0.003, and P=0.002) and worse baseline BCVA (logMAR) (β = 0.256, 95% CI: 0.072 to 0.439, and P=0.007). As for the nonsurgery group, younger baseline age (older age: β = −0.027, 95% CI: −0.048 to −0.007, and P=0.01) and longer baseline AL (β = 0.073, 95% CI: 0.023 to 0.122, and P=0.006) were associated with a higher change rate of AL.

Conclusions

The AL change rate was clearly associated with age both in the surgery group and in the nonsurgery group. Intervention strategies such as surgery should be performed earlier for CEL that meets the surgical criteria. Worse baseline BCVA and longer baseline AL are associated factors that would affect the growth rate of AL in the surgery and nonsurgery group, respectively.

Advisability of primary intraocular lens implantation for infants under 2: A systematic review and meta-analysis

PURPOSES

The present meta-analysis compared the postoperative visual performance of primary intraocular lens (IOL) implantation and primary aphakia in cataract infants.

METHODS

PubMed, Embase, Science Direct and Cochrane Library were searched, and postoperative visual acuity (VA) and complications were extracted and pooled.

RESULTS

Three randomised controlled trails (RCTs) and five retrospective studies were included. The postoperative VA of children younger than 4.5 years in primary IOL group was better than that in primary aphakia group [MD = -0.14, 95% CI: (-0.23, -0.06), P = .90]. The subgroup analysis based on RCTs and on unilateral cataract surgery revealed the same result. There was no significant difference in the incidence of glaucoma, strabismus, retinal detachment and nystagmus between primary IOL group and primary aphakia group [OR = 1.02, 95% CI: (0.62, 1.68), P = .48 for glaucoma; OR = 0.76, 95% CI: (0.30, 1.90), P = .05 for strabismus; OR = 0.49, 95% CI: (0.07, 3.30), P = .34 for retinal detachment; OR = 1.26, 95% CI: (0.68, 2.36), P = .92 for nystagmus]. The proportion of patients requiring postoperative visual axis opacification (VAO) clearing was higher in primary IOL group than that in primary aphakia group [OR = 9.22, 95% CI: (4.74, 17.96), P = .16].

CONCLUSION

For infants under 2 years of age, primary IOL implantation would provide more visual benefits compared with primary aphakia did, though the benefits would taper off with the age reaching 4.5 years. Moreover, the current study revealed a higher VAO incidence r in primary IOL implantation group.

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

PURPOSE

To report the change in globe axial length (AL) from the time of unilateral cataract surgery at age 1-7 months to age 10.5 years for infants enrolled in the Infant Aphakia Treatment Study, and to compare AL growth of operated eyes with that of fellow unoperated eyes.

DESIGN

Comparative case series.

METHODS

AL growth was analyzed relative to treated vs fellow eye, contact lens (CL) vs intraocular lens (IOL), visual acuity (VA) outcome, and the need for surgery for visual axis opacification. Eyes with glaucoma or glaucoma suspect were excluded from the primary analysis but reported separately.

RESULTS

Fifty-seven patients have reliable AL data available at both visits. AL was shorter in treated eyes preoperatively (P < .0001) and at 10.5 years of age (P = .021) but AL growth was not different (4.7 mm, P = .99). The growth (70.2% up to age 5 and 29.8% from age 5 to 10.5) was similar in the CL and the IOL group (P = .79). Eyes grew 4.4 mm when visual acuity (VA) was better than 20/200, and 5.2 mm when VA was 20/200 or worse (P = .076). Eyes receiving additional surgery grew more than eyes not receiving additional surgery (P = .052). Patients with glaucoma showed significantly more eye growth (7.3 mm) than those without glaucoma (4.7 mm) and glaucoma suspects (5.1 mm) (P < .05).

CONCLUSIONS

Eyes with glaucoma or poor VA often grew longer than the fellow eye. Overall, treated eyes grew similarly in the IOL and CL groups and also kept pace with the growth of the fellow eyes.

Comparison of the Accuracy of IOL Power Calculation Formulas for Pediatric Eyes in Children of Different Ages

Purpose

This study aims to compare the accuracy of five intraocular lens (IOL) power calculation formulas (SRK/T, Hoffer Q, Holladay 1, Haigis, and Holladay 2) for pediatric eyes in children of different ages.

Methods

In this prospective study, patients who received cataract surgery and IOL implantation in the capsular bag were enrolled. We compared the calculation accuracy of 5 formulas at 1 month postoperatively and performed subgroup analysis with the patients divided into three groups according to their ages at the time of surgery as follows: group 1 (age ≤ 2 years, 35 eyes), group 2 (2 years < age < 5 years, 38 eyes), and group 3 (age > 5 years, 29 eyes).

Results

75 patients (102 eyes) were enrolled in this study. The Haigis formula got the smallest PE among all formulas in all three groups. With regard to APE, there were no statistical differences among the formulas except group 2, with the SRK/T formula a little smaller, the Holladay 2 formula a little larger in group 1, and the Haigis formula a little smaller in group 3. In group 2, the Haigis formula had the lowest APE (0.87 ± 0.61 D), while the Holladay 2 formula had the largest (1.71 ± 1.20 D, p < 0.001), followed by the Holladay 1 formula (1.51 ± 1.07 D, p=0.002). On comparing the percentage of APE within 0.5 D and 1.0 D obtained with 5 formulas in each group, there were no statistical differences. The SRK/T formula and the Holladay 1 formula showed the highest percentage (40.00% and 60.00%) in group 1. While the Haigis formula got the highest percentage in less than 0.5 D (34.21%) and less than 1 D (60.53%) in group 2. In group 3, the Holladay 2 formula and the Haigis formula got the highest percentage less than 0.5 D (58.62%) and less than 1 D (79.31%). The multiple linear regression indicated that the age at the time of surgery was a significant factor affecting the accuracy of APE; after removing the age, AL was the only factor that affected the accuracy of APE.

Conclusion

The SRK/T and the Holladay 1 formulas were relatively accurate in patients younger than 2 years old, while the Haigis formula performed better in patients older than 2.

Factors influencing myopic shift in children after intraocular lens implantation

Introduction:

Intraocular lenses have always been a controversial topic in pediatric cataract surgery. In the early 1990s in the post-Soviet states of Eastern Europe, intraocular lenses promised an easier full-time correction and amblyopia treatment. Since 1991, ophthalmologists in Latvia have been implanting intraocular lenses in infants. Amount of the postoperative myopic shift and its influencing factors, analyzed in this article, are important indicators of congenital cataract treatment.

Materials and methods:

A retrospective chart review off 85 children (137 eyes) who underwent foldable posterior chamber intraocular lens implantation at the Clinical University Hospital in Riga, Latvia, from 1 January 2006 until 31 December 2016, was performed. Depending on the age at surgery, patients were divided into six groups: 1–6, 7–12, 13–24, 25–48, 49–84, and 85–216 months.

Results:

The largest and more variable myopic shift was found in a group of diffuse/total and nuclear cataract with surgery before the age of 6 months. There was a statistically significant correlation between the acquired best-corrected visual acuity and the amount of myopic shift (rs = 0.33; p < 0.001). Comparing the amount of myopic shift in two groups of different intraocular lens implantation target refraction tactics, we did not find statistically significant differences. Comparing the amount of myopic shift and implanted intraocular lens power, a negative, statistically significant correlation was found.

Conclusion:

The earlier the cataract extraction surgery and intraocular lens implantation is performed, the larger the myopic shift. The morphological type of cataract, best-corrected visual acuity, secondary glaucoma, and intraocular lens power influence the amount of myopic shift.

Relationship between preoperative axial length and myopic shift over 3 years after congenital cataract surgery with primary intraocular lens implantation at the National Institute of Ophthalmology of Peru, 2007-2011

Objective

To determine the relationship between the preoperative axial length and the myopic shift over 3 years after congenital cataract surgery with primary intraocular lens implantation and other related factors.

Methods

In this retrospective cohort study, the axial length was measured and assigned into 2 groups (>21.5 mm and ≤21.5 mm), visual axis obscuration, laterality of cataract, age of surgery and follow-up time were assessed and compared to the myopic shift.

Results

The mean myopic shift was 3.6 (standard deviation [SD]: 2.3) diopters (D) in all patients; 3.2 (3.3) and 3.9 (3.2) D for each group respectively (p=0.359). In unilateral cataracts the mean myopic shift was 6.3 D and in bilateral cases was 3.0 D (p=0.001). In bilateral cataracts, the shift was 2.6 D (SD: 2.0) and 3.4 D (SD: 1.8), respectively (p=0.098).

Conclusion

There was no relationship between the initial axial length and the myopic shift in all patients. Unilateral cataracts had a greater myopic shift over 3 years.

Central Corneal Thickness in Aphakic Children With Microcornea-Microphthalmia

PURPOSE

To study the central corneal thickness (CCT) in eyes with microcornea and aphakia and without glaucoma, compare it with normal controls, and correlate it with the measured intraocular pressure (IOP).

METHODS

The study was conducted on 62 eyes of 31 aphakic children with microcornea. Controls (20 children) were selected from age-matched children presenting for routine refraction. Detailed anterior-segment and fundus examinations were conducted. The CCT and the axial length were measured. Medical records of the study patients were reviewed for the stability of the ocular parameters over time to exclude glaucoma.

RESULTS

The mean±SD age of the study patients and controls were 4.0 (±3.1, 1.0 to 12.0) and 3.1 (±2.7, 0.6 to 12.0) years, respectively. The mean±SD CCT, the corneal diameter, the measured IOP, the cup/disc ratio, and the axial length of the study patients and the controls were 667.01±72.90 μm, 8.9±0.8 mm, 10.9±5.7 mm Hg, 0.1±0.1, 20.35±2.90 mm and 545.22±28.14 μm, 11.7±0.5 mm, 5.3±1.8 mm Hg, 0.1±0.1, and N/A, respectively. The difference between the study eyes and the controls in the CCT and the measured IOP was statistically significant (P<0.05).

CONCLUSIONS

Aphakic eyes with microcornea have thicker CCTs and greater measured IOPs than normal eyes. Hence, the measurement of CCT is recommended in the assessment of aphakic eyes with microcornea for possible glaucoma. The measured IOP, although a reliable parameter, in isolation does not provide a diagnosis of glaucoma and must be viewed in conjunction with other patient findings, such as the cup/disc ratio, the progression of which over time must be considered for a more solid diagnosis.

Globe Axial Length Growth at Age 5 Years in the Infant Aphakia Treatment Study

PURPOSE

To report the longitudinal change in axial length (AL) from the time of unilateral cataract surgery at age 1 to 7 months to age 5 years, and to compare AL growth of operated eyes with that of fellow unoperated eyes.

DESIGN

Comparative case series.

PARTICIPANTS

Infants enrolled in the Infant Aphakia Treatment Study (IATS).

METHODS

The AL at baseline and age 5 years and change in AL were analyzed relative to treated versus fellow eye, visual outcome, and treatment modality (contact lens [CL] vs. intraocular lens [IOL]). Eyes with glaucoma or glaucoma suspect were excluded from primary analysis but reported separately.

MAIN OUTCOME MEASURES

The AL growth from preoperative to age 5 years.

RESULTS

Seventy patients were eligible; however, AL data for both eyes were available for 64 patients at baseline and 69 patients at age 5 years. The AL was significantly different between treated and fellow eyes preoperatively (18.1 vs. 18.7 mm, P < 0.0001) and at the final follow-up (21.4 vs. 22.1 mm, P = 0.0004). The difference in AL growth between treated and fellow eyes was not significant (3.3 vs. 3.5 mm, P = 0.31). The change in AL in eyes was similar with both treatments (CL 3.2 mm and IOL 3.4 mm, P = 0.53) and did not correlate with visual outcomes (P = 0.85). Eyes receiving additional surgery to clear the visual axis opacification grew significantly more compared with eyes not receiving surgery to clear the visual axis (3.8 vs. 2.7 mm, P = 0.013). Patients with glaucoma showed significantly more eye growth (5.7 mm) than those without glaucoma (3.3 mm) and glaucoma suspects (4.3 mm).

CONCLUSIONS

Eyes treated for monocular cataract in infancy have axial growth similar to that of fellow eyes, despite having a shorter AL at the time of surgery. The change in AL in eyes was similar with both treatments (CL and IOL), did not correlate with visual outcomes, and was higher in eyes receiving additional surgery to clear the visual axis or eyes diagnosed with glaucoma.

Current Status of IOL implantation in pediatric eyes: an update

INTRODUCTION

Pediatric cataracts are a huge problem worldwide, and with improving techniques and technology, the surgical treatment and postoperative visual rehabilitation are improving. Despite intraocular lenses(IOLs) being the standard of care for adult cataract surgery, this issue is still somewhat controversial, particularly in young children and infants due to lack of unequivocal evidence. This review therefore summarises the findings from recent studies on the aspect of IOL implantation in pediatric eyes. Areas covered: An extensive literature search was undertaken for published articles on congenital/developmental pediatric cataracts, and IOL implantation, where literature pertinent to traumatic and subluxated cataracts was not included in the review. Pubmed was used for literature search, and keywords entered were : pediatric, cataract surgery, intraocular lens, persistent fetal vasculature, outcomes, complications, visual performance with intraocular lenses. Expert commentary: Recent literature supports IOL implantation in most cases of congenital / developmental pediatric cataracts, and it seems like the way forward. However, the jury is still out on IOL implantation in infants, particularly in bilateral cataracts. Thus, surgeons must be extremely cautious in planning primary IOL implantation in infant eyes, and if they do perform IOL implantation, rigorous followup is mandatory.

Long-term results after primary intraocular lens implantation in children operated less than 2 years of age for congenital cataract

PURPOSE

To study the long-term outcome of cataract surgery with primary intraocular lens (IOL) in children <2 years.

MATERIALS AND METHODS

Retrospective analysis of bilateral cases that were operated before 2 years age for congenital cataract. All underwent primary posterior capsulotomy with anterior vitrectomy and primary IOL implantation. Only those with a follow-up of at least 8 years were evaluated.

RESULTS

Twenty-six eyes of 13 children with bilateral cataract met the inclusion criteria. Average age at surgery was 14.15 months with a mean follow-up of 102 months. Average preoperative axial length (AL) was 19.93 mm. There was a refractive shift from a mean spherical equivalent of 1.64 D at 2 weeks after surgery to -1.42 D measured at last follow-up. Twenty-four eyes out of 26 (92%) achieved final visual acuity (VA) of 6/18 or more at last follow-up with 19/26 (73%) having acuity of 6/12 or greater. Raised intraocular pressure was documented in one eye only. Average AL recorded at last follow-up was 22.21 mm.

CONCLUSION

Primary IOL implantation in children <2 years is a safe surgical procedure with excellent long-term results. The myopic shift is well-controlled and final VA achieved is reasonably good.

Long-term postoperative outcomes after bilateral congenital cataract surgery in eyes with microphthalmos

PURPOSE

To evaluate the long-term impact of bilateral cataract surgery on postoperative complications, influence of age at surgery on the pattern of axial growth and central corneal thickness (CCT), and visual and orthoptic assessment in microphthalmic eyes.

SETTING

Iladevi Cataract and IOL Research Centre, Ahmedabad, India.

DESIGN

Prospective longitudinal study.

METHODS

This study assessed children with microphthalmos who had bilateral congenital cataract surgery. Microphthalmos was defined as an eye that has an axial length (AL) that was 2 standard deviations smaller than what is normally expected at that age. All eyes were left aphakic. One of the 2 eyes was randomly selected for analysis. Postoperative complications, AL, CCT, and visual acuity were documented.

RESULTS

This study included 72 eys of 36 children. The mean age of the patients was 4.8 months ± 6.2 (SD) (range 0.5 to 15 months). Postoperative complications included secondary glaucoma (11/36, 30.6%), visual axis obscuration (4/36, 11.1%), and posterior synechiae (10/36, 27.8%). A significant rate of change was observed in axial growth up to 4 years and in CCT up to 3 years postoperatively. When age at the time of surgery was correlated with the profile of the rate of change in AL and CCT at 1 month and 1, 2, and 4 years, statistically significant differences in AL and CCT at all timepoints were found. Loss of vision after surgery occurred in 2 eyes.

CONCLUSION

After early surgical intervention, an acceptable rate of serious postoperative complications and good visual outcomes were obtained in microphthalmic eyes.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Ocular axial growth in pseudophakic eyes of patients operated for monocular infantile cataract: a comparison of operated and fellow eyes measured at surgery and 5 or more years later

PURPOSE

To report the change in axial length (AL) over time and to compare the percentage of AL growth of pseudophakic eyes operated on for monocular cataract to that of the unoperated fellow eyes.

METHODS

The medical records of children operated on by a single surgeon for monocular congenital cataract before 7 months of age were retrospectively reviewed. Inclusion criteria were corneal diameter of ≥9 mm and availability of AL data for >5 years' follow-up after cataract surgery and >1 year after IOL implantation (in case of secondary IOL). Cataract with persistent fetal vasculature causing stretching of the ciliary processes, diagnosis of glaucoma or glaucoma suspect, and eyes with aphakia were excluded. Globe AL was measured by immersion ultrasound at surgery and 5 or more years later.

RESULTS

A total of 24 children were identified. Average age at cataract surgery was 2.6 ± 2.1 months. Age at last follow-up was 8.4 ± 2.8 years and duration of follow-up was 8.2 ± 2.8 years. 13 eyes received a primary IOL and 11 eyes received a secondary IOL. AL was significantly different between operative and fellow eyes, preoperatively (18.1 mm vs 18.7 mm, P = 0.004), and at the final follow-up (22.2 mm vs 23.0 mm, P = 0.03). Differences in AL growth of operated and fellow eyes were not significant (4.1 mm vs 4.4 mm, P = 0.4). Similarly, percentage of AL growth of operated and fellow eyes was also not significantly different (23% vs 23.6%, P = 0.7).

CONCLUSIONS

Eyes operated for monocular cataract have similar axial growth to that of fellow unoperated eyes, despite having a shorter AL at the time of surgery.

Effect of unilateral congenital cataract surgery on ocular axial length growth and corneal flattening

OBJECTIVE

The aim of this article is to study the effect of unilateral congenital cataract surgery on ocular growth and corneal flattening.

METHODS

This is a cross-sectional study of 59 patients operated on due to a unilateral congenital cataract. The median age of the patients at the time of diagnosis was 17 months (interquartile range, 5-39 months). The median age at cataract the time of surgery was 28 months (interquartile range, 8-52 months), and the mean follow-up between cataract surgery and assessments was 149.7±69.9 months (range, 30-319 months). Axial length and corneal curvature were measured in both operated and non-operated eyes, comparing the results between them.

RESULTS

There were no statistically significant differences for axial length growth or corneal flattening between operated and non-operated eyes: axial length (P=.327, Student t test) and corneal curvature (P=.078, Student t test). A sub-analysis was performed using the visual acuity and the age of the patient at the time of surgery. The only statistically significant data (P=.007, Student t test) was a lower axial length in operated eyes compared to non-operated eyes, in the non-deep-amblyopia group.

CONCLUSIONS

No significant axial length growth modifications were observed between operated and non-operated eyes. Only the non-deep-amblyopia group presented with a lower axial length in the operated eyes compared to non-operated eyes. No significant differences in corneal flattening were found between groups after unilateral congenital cataract surgery.

Pediatric cataract: challenges and future directions

Cataract is a significant cause of visual disability in the pediatric population worldwide and can significantly impact the neurobiological development of a child. Early diagnosis and prompt surgical intervention is critical to prevent irreversible amblyopia. Thorough ocular evaluation, including the onset, duration, and morphology of a cataract, is essential to determine the timing for surgical intervention. Detailed assessment of the general health of the child, preferably in conjunction with a pediatrician, is helpful to rule out any associated systemic condition. Although pediatric cataracts have a diverse etiology, with the majority being idiopathic, genetic counseling and molecular testing should be undertaken with the help of a genetic counselor and/or geneticist in cases of hereditary cataracts. Advancement in surgical techniques and methods of optical rehabilitation has substantially improved the functional and anatomic outcomes of pediatric cataract surgeries in recent years. However, the phenomenon of refractive growth and the process of emmetropization have continued to puzzle pediatric ophthalmologists and highlight the need for future prospective studies. Posterior capsule opacification and secondary glaucoma are still the major postoperative complications necessitating long-term surveillance in children undergoing cataract surgery early in life. Successful management of pediatric cataracts depends on individualized care and experienced teamwork. We reviewed the etiology, preoperative evaluation including biometry, choice of intraocular lens, surgical techniques, and recent developments in the field of childhood cataract.

Macular structural characteristics in children with congenital and developmental cataracts

PURPOSE

To investigate macular structural characteristics in children with congenital or developmental cataracts.

METHODS

Children 5-16 years of age with a history of surgery for congenital or acquired cataract were enrolled. Eligible patients had visual acuity of 20/400 or better and ≥37 weeks gestational age at birth. Patients were divided into two groups: unilateral (n = 22) and bilateral (n = 19). Fourier domain optical coherence tomography (FD-OCT) was used to image the retinal structure. Retinal volume scans centered on the fovea were obtained. Using the instrument's segmentation software, central subfield thickness (CST) and the thickness of the inner and outer retinal layer regions were measured.

RESULTS

In the unilateral group, 1 child with persistent fetal vasculature had unidentifiable retinal structure and was excluded. Most unilateral eyes (20/21) had a CST within the normal range. However, the CST, superior, nasal, inferior, and temporal sectors were all significantly thicker in the cataractous eye compared to the noncataractous eye (all P < 0.01 [paired t test]). The interocular difference for CST was not associated with age at surgery or interocular difference for visual acuity. In the bilateral group, although 34 of 38 eyes were within the normal range, the average CST of this group was significantly thicker than the noncataractous eye in the unilateral group.

CONCLUSIONS

Following cataract extraction during infancy or childhood, most cataractous eyes had normal macular structure. Cataractous eyes of both unilaterally and bilaterally affected children have thicker CST values compared to the noncataractous eye.

Axial length measurement techniques in pediatric eyes with cataract

Globe axial length (AL) in children is commonly measured using either contact or immersion technique. Office measurement of AL can be difficult in young children and infants and must often be done under anesthesia in an eye that is unable to cooperate with precise fixation and centration. Contact A-scan measurements yield shorter AL, on average, than immersion A-scan measurements in pediatric eyes. This difference is mainly the result of the anterior chamber depth rather than the lens thickness value. During intraocular lens power calculation, if globe axial length is measured by the contact technique, it will result in the use of an average 1-D stronger IOL power than is actually required. This can lead to induced myopia in the postoperative refraction. In our studied patients, there was a significant difference in prediction error between contact A-scan biometry and immersion A-scan biometry. The immersion A-scan technique is recommended for pediatric IOL power calculation. We also provide a review of biometry in pediatric eyes. The overall mean AL of pediatric cataractous eyes is significantly different than the mean AL of non cataractous eyes. More importantly, the standard deviation is higher in eyes with cataract than in those without. Three phases of eye growth in children have been documented: A rapid, postnatal phase from birth to 6 months of age, followed by a slower, infantile phase from 6 to 18 months of age, and finally a slow, juvenile phase from 18 months forward. In our study, girls had shorter ALs than boys and African-American subjects had longer ALs than Caucasians. Eyes with unilateral cataract had shorter ALs than eyes with bilateral cataract during the earlier years, but had longer ALs during later childhood.

Axial elongation following cataract surgery during the first year of life in the infant Aphakia Treatment Study

PURPOSE

To compare ocular axial elongation in infants after unilateral cataract surgery corrected with a contact lens (CL) or primary intraocular lens (IOL) implantation.

METHODS

Baseline axial length (AL) was measured at the time of cataract surgery (1-6 months) and at age 1 year. AL at baseline and age 1 year and the change in length/mo were analyzed in relation to treatment modality, cataractous versus fellow eye, and age at surgery using linear mixed models.

RESULTS

Mean baseline AL did not differ between the CL and IOL groups for either cataractous or fellow eyes. Eyes with cataracts were shorter than fellow eyes by an average of 0.6 mm (95% confidence interval [CI], 0.4-0.8 mm; P < 0.0001). For the operated eyes, the mean change in AL/mo was smaller in the CL group (0.17 mm/mo) than in the IOL group (0.24 mm/mo) (P = 0.0006) and was independent of age at surgery (P = 0.19). In contrast, the change in AL/mo for fellow eyes decreased with older age at surgery (P < 0.0001). At age 1 year, operated eyes treated with a CL were 0.6 mm shorter on average than operated eyes treated with an IOL (P = 0.009).

CONCLUSIONS

At baseline, eyes with cataracts were shorter than fellow eyes. The change in AL/mo was smaller in operated eyes treated with a CL than in operated eyes treated with an IOL, but was not significantly related to age at surgery. (ClinicalTrials.gov number, NCT00212134.).

Long-term Outcomes of Undercorrection Versus Full Correction After Unilateral Intraocular Lens Implantation in Children

PURPOSE

To evaluate the impact of full correction vs undercorrection on the magnitude of the myopic shift and postoperative visual acuity after unilateral intraocular lens (IOL) implantation in children.

DESIGN

Retrospective case control study.

METHODS

The medical records of 24 children who underwent unilateral cataract surgery and IOL implantation at 2 to <6 years of age were reviewed. The patients were divided into 2 groups based on their 1-month-postoperative refraction: Group 1 (full correction) -1.0 to +1.0 diopter (D) and Group 2 (undercorrection) ≥+2.0 D. The main outcome measures included the change in refractive error per year and visual acuity for the pseudophakic eyes at last follow-up visit. The groups were compared using the independent groups t test and Wilcoxon rank sum test.

RESULTS

The mean age at surgery (Group 1, 4.2±0.9 years, n=12; Group 2, 4.5±1.0 years, n=12; P=.45) and mean follow-up (Group 1, 5.8±3.7 years; Group 2, 6.1±3.5 years; P=.69) were similar for the 2 groups. The change in refractive error (Group 1, -0.4±0.5 D/y; Group 2, -0.3±0.2 D/y; P=.70) and last median logMAR acuity (Group 1, 0.4; Group 2, 0.4; P=.54) were not significantly different between the 2 groups.

CONCLUSIONS

We did not find a significant difference in the myopic shift or the postoperative visual acuity in children aged 2 to <6 years of age following unilateral cataract surgery and IOL implantation if the initial postoperative refractive error was near emmetropia or undercorrected by 2 diopters or more.

Peripheral refraction in pseudophakic eyes measured by infrared scanning photoretinoscopy

PURPOSE

To obtain quantitative data of peripheral refractive errors in pseudophakic eyes including measurements up to ±45 degrees on the retina.

SETTING

University Eye Hospital, Tübingen, Germany.

DESIGN

Population-based cross-sectional study.

METHODS

Pseudophakic and phakic subjects were measured with a purpose-built scanning photorefractor. The instrument was improved over previous versions. It permits measurement of semicontinuous peripheral profiles over the central 90-degree field of the retina at a faster speed (4 s/scan).

RESULTS

Twenty-four pseudophakic and 43 phakic subjects were enrolled. The intraocular lenses (IOLs) induced a mean myopic shift of 2.00 diopters (D) at ±45 degrees of eccentricity in the vertical pupil meridian. Ray-tracing simulations with phakic eye and pseudophakic eye models agreed well with the experimental data. They showed that changes induced by IOLs were a consequence of an increase in astigmatism with eccentricity and a myopic shift in the spherical equivalent.

CONCLUSIONS

The peripheral refractions in pseudophakic eyes were more myopic than in phakic eyes as a consequence of the optical design of the IOLs. Whether a more myopic refraction of approximately 2.00 D at 45 degrees has significant effects on visual performance must be tested. Perhaps there is room for improvement in the peripheral optics of IOLs.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Partial coherence interferometry versus immersion ultrasonography for axial length measurement in children

PURPOSE

To determine whether measurements obtained by partial coherence interferometry (PCI) correlate well with measurements obtained using immersion ultrasound (US) in children.

SETTING

Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, USA.

DESIGN

Evaluation of a diagnostic test or technology.

METHODS

The charts of pediatric patients who had cataract surgery from August 2008 to September 2009 were reviewed. Axial length (AL) measurements in the operative eye were obtained using PCI at the preoperative clinic visit and then using immersion US in the operating room before surgery. The data were compared to determine the degree of agreement.

RESULTS

The charts of 18 patients (27 eyes) were reviewed. Preoperative AL measurements by PCI were obtained in 21 eyes (78%). On average, the PCI-measured ALs were 0.1 mm less than the immersion US values (95% confidence interval, -0.2 to -0.1; P = .002). All eyes with an AL of 23.5 mm or less had lower PCI values than immersion US values. There was no systematic pattern of 1 measurement being greater or less than the other in eyes with an AL longer than 23.5 mm.

CONCLUSIONS

There was a systematic difference in AL measurement between PCI and immersion US, with PCI tending to give lower values, particularly in eyes with an AL of 23.5 mm or less. Depending on the length of the eye, a 0.1 mm error in AL measurement could result in a 0.25 to 0.75 diopter difference in intraocular lens calculation that could be clinically significant in some patients.

The outcome of congenital cataract surgery in Kuwait

AIM

Congenital cataract is the most common cause of treatable blindness in children and the outcome of congenital cataract surgery has not been studied in Kuwait, so the purpose of this study is to evaluate the visual outcome and the postoperative complications.

METHODS

Medical records of children who underwent congenital cataract surgery between September 2000 and December 2008 at Al-Bahar Eye Center, Ministry of Health of Kuwait were retrospectively reviewed. In 100 eyes that fill the inclusion criteria visual acuity and postoperative complications were recorded. The mean follow up was 3.9 ± 1.7 years with range from 3 to 6 years.

RESULTS

The mean age of congenital/developmental cataract surgery is 8.9 ± 8.7 months for bilateral cases and it was 5.75 ± 4.61 months for unilateral cases. The mean final postoperative BCVA in unilateral cases was 1.0 (20/200) log MAR unit and it was 0.3 (20/40) log MAR unit for the bilateral cases. Four percent of the cases developed postoperative glaucoma and 2% of them developed significant opacification of the posterior capsule.

CONCLUSION

Our findings provide evidence of recent improvement over time in the visual prognosis in bilateral, and to a lesser degree, unilateral cataract, in children in Kuwait.

Axial growth and binocular function following bilateral lensectomy and scleral fixation of an intraocular lens in nontraumatic ectopia lentis

PURPOSE

To evaluate binocular function (BF) and changes in axial length (AL) bilaterally in pseudophakic eyes of children after lensectomy and scleral fixation of an intraocular lens (IOL) for nontraumatic ectopia lentis.

METHODS

In 15 children who had undergone bilateral lensectomy and scleral fixation of an IOL for nontraumatic ectopia lentis, AL was measured preoperatively and at last follow-up, and BF was assessed at last follow-up. Axial growth was compared with the expected and observed patterns of normal eyes, and the results were compared between patients with isolated ectopia lentis and those with Marfan syndrome.

RESULTS

Ten of the 15 patients had Marfan syndrome. Mean age at surgery was 5.2 +/- 2.4 years; mean follow-up was 51.7 +/- 29.2 months. A mean axial growth rate of 0.39 mm/year during 51.7 postoperative months was greater than the expected (0.07 mm/year) or the observed (0.09-0.24 mm/year) rates in age-matched normal eyes. The axial growth rates in isolated ectopia lentis patients and Marfan patients were not significantly different (P = 0.159). Binocular fusion and stereoacuity of < or =800 seconds of arc were achieved by nine patients, and worse or no BF was achieved by the remaining six patients. These six patients were significantly more likely to have pre- or postoperative anisometropia of > or =3.0 D (66.6%) than the other nine patients (0%).

CONCLUSIONS

Because of greater than normal axial growth, more undercorrection of the IOL power is required than is usual in bilateral surgery for nontraumatic ectopia lentis. Good or moderate levels of postoperative BF were achieved in more than half of patients.

Unilateral axial length elongation with chronic traumatic cataracts in young Kenyans

PURPOSE

To assess whether unilateral axial elongation in chronic traumatic cataract is associated with the time interval from trauma to surgery.

SETTING

PCEA Kikuyu Hospital Eye Unit, Nairobi, Kenya.

METHODS

This retrospective cohort study analyzed patients with traumatic cataract operated on between 1998 and 2007. Study patients (n = 13) had a delay from trauma to surgery of more than 1 year and an interocular axial length (AL) difference greater than 1.0 mm. Randomly selected age-matched control patients (n = 14) had less than 1 year delay between trauma and surgery. The correlation between interocular AL difference and surgical delay was calculated in each group.

RESULTS

The median interval from trauma to surgical treatment in study patients was 8 years (range 1 to 27 years). Study patients had a significantly higher median interocular AL difference (3.09 mm; interquartile range [IQR] 2.45 to 4.13 mm) than control patients (0.24 mm; IQR 0.15 to 0.30 mm) (P = .000). The length of delay from trauma to surgical treatment did not correlate strongly with the interocular AL difference in study or control patients (R(2) = 0.0143 and R(2) = 0.1697, respectively).

CONCLUSIONS

Unilateral AL elongation may occur in young adults with chronic traumatic cataract. Delay of more than 1 year from trauma to surgery was associated with axial elongation, although the degree of elongation did not correlate with duration of delay. Surgeons are advised to implant lower-power intraocular lenses in such patients based on biometry readings to avoid postoperative refractive surprises.

Emmetropization and eye growth in young aphakic chickens

PURPOSE

To establish a chick model to investigate the trends of eye growth and emmetropization after early lensectomy for congenital cataract.

METHODS

Four monocular treatments were applied: lens extraction (LX); sham surgery/-30 D lens; LX/+20 D lens; and LX/+30-D lens (nine per group). Lens powers were selected to slightly undercorrect or overcorrect the induced hyperopia in LX eyes and to induce comparable hyperopia in sham-surgery eyes. Refractive errors and axial ocular dimensions were measured over a 28-day period. External ocular dimensions were obtained when the eyes were enucleated on the last day.

RESULTS

The growth patterns of experimental (Exp) eyes varied with the type of manipulation. All eyes experiencing hyperopia initially grew more than their fellow eyes and exhibited myopic shifts in refraction. The sham/-30 D lens group showed the greatest increase in optical axial length, followed by the LX group, and then the LX/+20 D lens group. The Exp eyes of the LX/+30 D lens group, which were initially slightly myopic, grew least, and showed a small hyperopic shift. Lensectomized eyes enlarged more equatorially than axially (i.e., oblate), irrespective of the optical treatment applied.

CONCLUSIONS

The refractive changes observed in young, aphakic eyes are consistent with compensation for the defocus experienced, and thus emmetropization. However, differences in the effects of lensectomy compared to those of sham surgery raise the possibility that the lens is a source of essential growth factors. Alterative optical and mechanical explanations are offered for the oblate shapes of aphakic eyes.

Intraocular lens power calculation in children

With improving surgical technique and equipment, the acceptable age for placing an intraocular lens in infants and children is becoming younger. The tools for predicting intraocular lens power have not necessarily kept up, as current theoretical and regression intraocular lens power prediction formulas are largely based on adult eyes at axial lengths, anterior chamber depth, and keratometric values much different than those seen in infants. In addition, the adult eye has matured and is no longer growing, whereas the eyes of infants and children may continue to note changes in axial length, keratometric values, and possibly optical characteristics. Another source of error in intraocular lens power selection that is more likely to occur in pediatric patients than in adult patients is inaccuracy in measurement of axial length or keratometric power. A review of current tools and considerations for intraocular lens power prediction in infants and children is presented.

Cataract surgery for congenital cataract: endothelial cell characteristics, corneal thickness, and impact on intraocular pressure

PURPOSE

To investigate whether central corneal thickness (CCT), endothelial cell characteristics, and intraocular pressure (IOP) are affected in patients with previous congenital cataract surgery and to focus on their clinical significance.

METHODS

CCT and IOP measurements and specular microscopy were performed in 31 eyes of 17 cases of extracted congenital cataracts and 40 eyes of 20 age- and sex-matched participants as control group. The mean of three pachymetry measurements of the central cornea was taken as CCT. IOP was checked using an applanation tonometer.

RESULTS

The mean corneal thickness of the eyes with extracted congenital cataract (632+/-45 microm) was significantly greater than that of the control eyes (546+/-33 microm; p<0.001). There was no significant difference in the corneal endothelial cell count, coefficient of variation (CV), and mean cell area (AVG) of endothelial cells between operated eyes and the control group. The mean measured IOP in the operated group (22.8+/-3.3 mm Hg) was significantly greater than IOP in controls (14.1+/-1.8 mm Hg, p<0.001).

CONCLUSIONS

Although the corneas were clinically clear and there was no significant difference in endothelial characteristics of eyes with extracted congenital cataract and controls, central corneas of operated eyes were significantly thicker than those of controls. To differentiate the actual glaucoma from ocular hypertension in these patients, the central corneal thickness measurement should strongly be considered.

Cataractes congénitales unilatérales opérées précocement : devenir réfractif à long terme

PURPOSE

Predict long-term refractive changes after primary lens implantation for unilateral congenital cataract in order to know the intraocular lens power to use to obtain best functional results.

METHODS

This retrospective study analyzed 53 children with unilateral congenital cataract operated on with primary intraocular lens implantation, with a mean follow-up of 6.8 years. The mean age at surgery was 2.98 years.

RESULTS

The mean myopic shift per year was -0.83 D/year. Children operated on before the age of 2 years had a mean myopic shift of -9.15 D, and others presented -2.13 D. The variability of myopic shift decreased with age. The mean visual acuity was +0.25 logMAR. Four intraocular lenses were changed because of substantial anisometropia.

CONCLUSION

Early surgery with primary implantation and intensive amblyopia treatment provide good long-term visual results. Long-term refractive changes of very young children operated on for unilateral congenital cataract is extremely variable. Changing the intraocular lens is conceivable when substantial anisometropia slows down amblyopia rehabilitation.

Ocular axial length changes in pseudophakic children after traumatic and congenital cataract surgery

BACKGROUND

Pseudophakic children tend to develop a large myopic shift. This may be in part due to accelerated growth in axial length. The purpose of this study was to evaluate and compare the postoperative change in axial length (DeltaAL) in pseudophakic eyes, after extraction of traumatic or congenital cataract.

METHODS

Included in this retrospective study were 20 children who had undergone surgery for traumatic, unilateral congenital, or bilateral congenital cataracts. All patients were under 10 years old at the time of operation. Axial length was measured perioperatively as well as 1 year or more postoperatively. The three groups were subdivided according to patients' ages (below or above 5 years). The DeltaAL in the operated eyes was compared with DeltaAL of the fellow nonoperated eyes. The difference in DeltaAL between operated and fellow nonoperated eyes was compared among the groups.

RESULTS

DeltaAL was greater for operated eyes than for fellow nonoperated eyes (traumatic cataract: p=0.06; unilateral congenital cataract, p=0.055). Axial elongation was significantly greater in children under 5 years old at operation than in those older than 5 (p=0.025). The difference in rate of DeltaAL between operated and fellow nonoperated eyes, per 1 year of follow-up, was similar for traumatic and unilateral congenital cataract groups.

CONCLUSIONS

This study demonstrated a tendency toward greater axial lengthening in pseudophakic eyes of children, when compared with their nonoperated eyes. No significant difference was found in the tendency for increased axial lengthening between eyes operated on for traumatic cataracts and those operated on for congenital cataracts.

Changes in refraction and ocular dimensions after cataract surgery and primary intraocular lens implantation in infants

PURPOSE

To study refraction and axial length changes after cataract extraction and primary intraocular lens (IOL) implantation in children younger than 1 year of age.

SETTING

Two regional hospitals.

METHODS

After determining the IOL power for emmetropia, 80% of the value was used to choose the IOL for implantation to counter anticipated myopic shift with age. The main outcome measures were changes in refraction and axial length 3 years after surgery.

RESULTS

Thirty-four eyes of 20 children (mean age 6.7 months +/- 3.9 [SD]) were studied. Refraction in the immediate postoperative period was +4.53 +/- 1.45 diopters (D). Three years after surgery, the mean refraction was -2.49 +/- 3.08 D (P<.001). Twenty-two eyes (64.7%) had surgery during the first 6 months of life (group 1) and had a shorter axial length at surgery (mean 18.92 +/- 1.32 mm) compared with 12 eyes (35.3%) that received surgery between 7 and 12 months (group 2, mean 20.29 +/- 1.00 mm) (P = .007). However, the final axial length was greater in group 1 (mean 22.67 +/- 1.04 mm) than in group 2 (mean 21.23 +/- 0.26 mm) (P = .019).

CONCLUSIONS

Primary IOL implantation is an option for children having cataract surgery in the first year of life. Significant myopic shifts occurred, and this seemed to be more pronounced in younger children. It appears that rethinking current strategies for IOL power calculation may be required to achieve more optimal refractive outcomes.

Updates on the Surgical Management of Paediatric Cataract with Primary Intraocular Lens Implantation

With the advent of modern surgical techniques, paediatric cataract has become much more manageable. Intraocular lens (IOL) implantation is the standard of care for patients over the age of 2 years. The use of IOL in young infants is still controversial. In addition, there are still unresolved issues, such as the minimum age at which IOL can be safely implanted, IOL power selection and IOL power calculation. The current trends in the management of the above challenges are discussed. Although numerous reports on the prevention and management of posterior capsule opacification have been published, there are ongoing intensive debates and research. Long-term postoperative complications like glaucoma and rhegmatogenous retinal detachment are problems that cannot be overemphasised and these issues are also reviewed. Key words: Congenital cataract, Intraocular lens, Posterior capsule opacification

Rate of axial growth after congenital cataract surgery

PURPOSE

To evaluate the rate of axial growth after congenital cataract surgery.

DESIGN

Prospective observational case series.

METHODS

Rate of axial growth of 158 eyes (79 children < 10 years) undergoing surgery was correlated with age at surgery, laterality, and visual axis obscuration. After measuring axial length (AL) at each follow-up, the mean AL was calculated, adding the AL of all eyes divided by their total number. Rate of axial growth is the percentage difference between preoperative mean AL and mean AL at last follow up. The temporal profile of RAG is the difference between two consecutive mean ALs with respect to the previous reading. The follow-up period was 58.96 +/- 2.02 months. The student' paired t test and independent sample t test were applied. The main outcome measure was RAG.

RESULTS

Rate of axial growth in children operated at < or = 1 year (23.5%) was significantly higher than in those at < or = 3 years (4.8%; P = .0001, confidence interval [CI] 1.05-3.2) and at < or = 10 years (4.3%; P = .0001, CI 1.3-3.1). In children operated at <or = 1 year, temporal profile of RAG was higher in the first 2 years after surgery. Rate of axial growth was higher in patients with unilateral pseudophakia at < or = 1 year (25.53%) than in age-matched patients with bilateral pseudophakia (18.50%; P = .001, CI -13 to -0.2). Rate of axial growth was negligible in children with visual axis obscuration in any group.

CONCLUSION

Rate of axial growth is higher in children < or = 1 year and increases until the second year after surgery. Unilateral pseudophakia revealed accelerated growth compared with bilateral pseudophakia. Visual axis obscuration does not influence rate of axial growth.

Is early surgery for congenital cataract a risk factor for glaucoma?

AIMS

To estimate the risk of aphakic glaucoma after lensectomy for congenital cataract and its association with surgery within the first month of life.

METHOD

A retrospective case notes review was conducted of all patients who had lensectomy for congenital cataract during their first year of life at Great Ormond Street Hospital between 1994 and 1997. Patients with pre-existing glaucoma, anterior segment dysgenesis, and Lowe syndrome were excluded. The risk of aphakic glaucoma after surgery was estimated using Kaplan-Meier survival analysis.

RESULTS

80 patients, undergoing 128 lensectomies were eligible. Of these, six patients (nine eyes) were lost to follow up. Based on eye count, the risk of glaucoma by 5 years after lensectomy was 15.6% (95% CI 10.2 to 23.4). Based on patient count, the 5 year risk of glaucoma in at least one eye following bilateral surgery was 25.1% (95% CI 15.1 to 40.0). The incidence of glaucoma remained at a constant level for the first 5 years after surgery. After early bilateral lensectomy, within the first month of life, the 5 year risk of glaucoma in at least one eye was 50% (95% CI 27.8 to 77.1) compared to 14.9% (95% CI 6.5 to 32.1) with surgery performed later (log rank test, p = 0.012). There was no significant difference (Kolmogorov-Smirnov test: unilateral lensectomy p = 0.587, bilateral lensectomy p = 0.369) in 5 year visual outcomes between eyes operated before and after 1 month of age.

CONCLUSION

Bilateral lensectomy during the first month of life is associated with a higher risk of subsequent glaucoma than with surgery performed later. The reason for this is unclear but it may be prudent, in bilateral cases, to consider delaying surgery until the infant is 4 weeks old. As the incidence of glaucoma is similar for each year after surgery, long term glaucoma surveillance is mandatory.

Intraocular lens implantation during infancy: perceptions of parents and the American Association for Pediatric Ophthalmology and Strabismus members

BACKGROUND

To determine whether a randomized clinical trial, the Infant Aphakia Treatment Study, comparing intraocular lens (IOL) implantation with contact lens (CL) correction for infants with a unilateral congenital cataract (UCC), is feasible by (1) ascertaining whether American Association for Pediatric Ophthalmology and Strabismus (AAPOS) members have equipoise regarding these two treatments and (2) evaluating the willingness of parents to agree to randomization.

METHODS

All AAPOS members were surveyed in August 1997 and again in June 2001 regarding their use of CLs and IOL implants to correct infants vision after unilateral cataract surgery. In addition, a pilot study was begun in March 2002 to evaluate the safety of IOL implantation during infancy and the willingness of parents to randomize their children with a UCC to either IOL implantation or CL correction.

RESULTS

In 1997, 89% of the 260 respondents reported that in the previous year they had treated at least one infant with a UCC, but only 4% had implanted an IOL in an infant <7 months old. Silsoft (Bausch & Lomb, Rochester, NY) CL correction was the preferred treatment choice for 84% of the respondents. In 2001, 21% of the 279 respondents had implanted an IOL in an infant. On a scale from 1 to 10 with 1 strongly favoring an IOL implant and 10 strongly favoring a CL, the median score was 7.5. Sixty-one percent of the respondents indicated that they would be willing to randomize children with a UCC to one of these two treatments. The main concerns about IOL implantation were poor predictability of power changes, postoperative complications, inflammation, and technical difficulty of surgery. The main concerns about CL correction were poor compliance, high lens loss rate, high cost, and keratitis. In our pilot study, 30 infants <7 months of age were evaluated at nine clinical centers for a visually significant UCC. Of 24 infants eligible for randomization, the parents of 17 (71%) agreed to randomization.

CONCLUSIONS

Although most AAPOS members still favor CL correction after cataract surgery for a UCC, five times as many had implanted an IOL in an infant in 2001 compared with the number in 1997. Parents were almost equally divided in their preference for IOL implant versus CL correction. Given the relative equipoise of AAPOS members regarding these treatments and the willingness of more than two thirds of parents to agree to randomization, it seems likely that a randomized clinical trial comparing these two treatments could indeed be conducted.

Results and complications of hydrophobic acrylic vs PMMA posterior chamber lenses in children under 17 years of age

PURPOSE

To compare results and complications of implantation of hydrophobic acrylic foldable intraocular lenses in children with those of polymethylmethacrylate (PMMA) intraocular lenses.

METHODS

In a retrospective study, we analyzed results of cataract surgery with posterior chamber lens implantation in 30 eyes of 30 patients aged 1-16 years. In 10 eyes, acrylic (Alcon AcrySof) intraocular lenses, and in 20 eyes, single-piece PMMA posterior chamber lenses were implanted. Indications for cataract surgery (blunt or penetrating trauma, zonular cataract, cataracta polaris posterior, posterior lenticonus) and mean age at implantation were comparable in the two groups. Mean patient age at surgery was 8.6+/-4.6 years (range 3-16 years) for the acrylic vs 6.3+/-4.3 years (range 1-16 years) for the PMMA group. Mean follow-up was 1.0+/-0.7 years (range 0.1-2.2 years) in the acrylic group and 1.8+/-1.5 years (range 0.1-5.7 years) in the PMMA group. Primary anterior vitrectomy was performed in 7 eyes in the PMMA group and in 3 eyes in the acrylic group. In addition, one additional posterior capsulorhexis without anterior vitrectomy was performed in each group. Primary outcome measure was the occurrence of postoperative "complications" (fibrin, synechiae, posterior capsular opacification). For statistical evaluation, the Fisher exact test was used.

RESULTS

When evaluating all complications together (at least one complication vs no complication), there were significantly less complications in the acrylic group (2 of 10 vs 15 of 20; p=0.007. For early complications (postoperative fibrin, synechiae) the difference was also significant (1 of 10 in the acrylic vs 11 of 20 in the PMMA group; p=0.02). The rate of posterior capsular opacification necessitating YAG capsulotomy was lower in the acrylic group (1 of 10 eyes) than in the PMMA group (7 of 20 eyes), but the difference did not reach statistical significance ( p=0.67). The postoperative time point of YAG capsulotomy was 21 months in the acrylic group and 19+/-10 months (range 6-33 months) in the PMMA group. IOL dislocation was not observed in any of the patients. Postoperative visual acuity was comparable in the two groups: 0.57+/-0.35 (0.03-1.0) in the acrylic vs 0.39+/-0.34 (0.001-0.9) in the PMMA group ( p=0.83).

CONCLUSIONS

Implantation of hydrophobic acrylic intraocular lenses in the capsular bag in children may be associated with less postoperative complications compared with implantation of PMMA lenses. This appears also to be true in children under age 6 years. The visual results seem comparable and correspond mainly to the underlying ocular pathology.

Case series of 12 children with progressive axial myopia following unilateral cataract extraction

PURPOSE

We report the occurrence of unilateral progressive axial myopia ipsilaterally in a retrospective analysis of 12 children following uniocular cataract surgery.

METHODS

A retrospective analysis of the case records of children who had developed progressive ipsilateral axial myopia following unilateral cataract surgery was done. Follow-up ranged from 4 years to 14 years.

RESULTS

Twelve children, 7 male and 5 female, were eligible for the study. Mean age at the time of cataract surgery was 6.7 +/- 2.5 years (range, 4-11 years) and follow-up period was 7.8 +/- 3.1 years (range, 4-14 years). Ten children (83.3%) had traumatic cataracts of which 8 had undergone repair of penetrating eye injuries and 2 had suffered blunt trauma. Two patients (16.7%)had been operated for unilateral developmental cataracts. Three children had aphakia and nine had pseudophakia. Degree of myopic shift ranged from -4.75 D to -15 D (mean, -7.35 +/- 3.51 D). Axial length difference between the 2 eyes ranged from 1 mm to 3.5 mm (mean, 2.2 +/- 0.9 mm). Mean increase of axial length from preoperative recording to final follow-up was 2.53 +/- 0.90 mm (range, 1.6-4 mm). Three children had to undergo IOL explantation and 1 had posterior chamber intraocular lens exchange due to high unilateral myopia. The rest were visually rehabilitated with either spectacles or contact lenses.

CONCLUSION

Following cataract surgery pediatric eyes may suffer from progressive axial myopia. Trauma or multiple ocular surgeries may be predisposing factors.

Pseudophakia and polypseudophakia in the first year of life

PURPOSE

To report a consecutive series of patients undergoing intraocular lens (IOL) implantation in the first year of life. A new procedure, referred to as temporary polypseudophakia, is reported.

METHODS

A retrospective chart analysis was conducted. Ocular growth and refractive change, complications and reoperation rates, and outcomes were analyzed.

RESULTS

Forty-seven eyes of 33 patients underwent IOL implantation in the first year of life. Average follow-up was 22 months (range, 7 weeks to 5 years). Thirty-two eyes of 22 patients had a single IOL implanted from 12 days to 11 months of age. Fifteen eyes of 11 infants received piggyback IOLs from 16 days to 6.8 months of age. Reoperation for complications within the anterior segment of the eye was needed in 23% of all patients (22% for single IOLs, 26% for piggyback IOLs). The average first postoperative refraction after single IOL was +7.98 D and after piggyback IOL was +1.67 D. The average last postoperative refraction was +1.76 D and -4.48 D, respectively. On average, eyes grew 2.68 mm over 17.5 months of follow-up. Eight patients were old enough for Snellen visual acuity, but each had deprivation amblyopia with visual acuities from 20/85 to 5/200. Of the remaining 25 patients, 17 had central, steady, and maintained fixation in the implanted eyes.

CONCLUSION

IOL implantation in infancy is technically feasible and associated with a reoperation rate of approximately 25% in the first 2 years after implantation. Further follow-up is required before meaningful visual acuity data and long-term results can be reported.

Intraocular lens designed for the newborn infant eye

PURPOSE

To evaluate the effects of an intraocular lens (IOL) designed for small eyes after clear lens extraction in an animal model.

SETTING

St. Erik's Eye Hospital, Karolinska Institute, Stockholm, Sweden.

METHODS

Clear lens extraction was performed in both eyes in 19 3-week-old rabbits. In 1 randomly selected eye of each rabbit, a small IOL with long haptics was implanted. Axial length, corneal thickness, corneal diameter, and intraocular pressure were measured preoperatively and every month for 6 months postoperatively. Six months after surgery, the wet mass of the after-cataract was determined.

RESULTS

The IOL remained well centered in all eyes. Four animals developed severe glaucoma in 5 eyes (3 aphakic and 2 pseudophakic) soon after surgery and were excluded. In the 15 animals completing the study, signs of glaucoma evolved in 7 animals (5 aphakic and 4 pseudophakic eyes). In aphakic eyes, significant amounts of after-cataract (median 250 mg) developed in all 15 surviving animals. In pseudophakic eyes, small amounts of after-cataract (median 30 mg) were present. During the first 2 months after surgery, ocular growth was less in pseudophakic eyes than in aphakic eyes.

CONCLUSIONS

Results indicate that implantation of a down-sized IOL with long haptics in small eyes is safe. Considerable less after-cataract was found in eyes with the IOL than in aphakic control eyes.

Influence of monocular deprivation during infancy on the later development of spatial and temporal vision

Using the method of limits, we measured spatial and temporal vision in 15 patients, aged 4-28 years, who had been monocularly deprived of patterned visual input during infancy by a dense cataract. All patients showed losses in both spatial and temporal vision, with greater losses in spatial than in temporal vision. Losses were smaller when there had been more patching of the non-deprived eye. The results indicate that visual deprivation has smaller effects on the neural mechanisms mediating temporal vision than on those mediating spatial vision.

Intra-ocular lens implantation in children

Intra-ocular lens (IOL) implantation in a growing eye of a young child brings several problems unique to this age group. Better understanding of the rate of refractive growth in children's pseudophakic eyes may help predicting future refractions in these eyes more accurately. Opacification of the posterior capsule, if remained intact, interferes with visual rehabilitation in children. Primary posterior capsulectomy and anterior vitrectomy provides the clarity of visual axis. Optical rehabilitation of children with unilateral aphakia is usually problematic. Posterior chamber IOLs are preferred to anterior-chamber IOLs for secondary implantation. In the absence of adequate capsular support and contact lens intolerance, a scleral-fixated IOL can be implanted. Scleral fixation of a posterior chamber IOL has encouraging short-term results but the long-term risks are not known yet. Intra-ocular lens implantation in infants is associated with major complications and is not recommended at present. The occurrence of open angle glaucoma is a sight-threatening late complication of pediatric cataract surgery. Intra-ocular lens implantation plays a protective role against aphakic glaucoma in children.