A comparison of the rate of refractive growth in pediatric aphakic and pseudophakic eyes

Evaluation of functional vision and eye-related quality of life in children with congenital ectopia lentis: a prospective cross-sectional study

OBJECTIVES

This study aims to evaluate the effect of congenital ectopia lentis (CEL) on functional vision and eye-related quality of life (ER-QOL) in children and their families using the Paediatric Eye Questionnaire (PedEyeQ).

DESIGN

A questionnaire survey administered via in-person interviews of patients with CEL and their parents.

PARTICIPANTS

51 children with CEL and 53 visually normal controls accompanied by 1 parent completed the survey questionnaires for the study from March 2022 to September 2022.

OUTCOME MEASURES

PedEyeQ domain scores. Functional vision and ER-QOL of children and their families were evaluated by calculating and comparing the Rasch domain scores of the PedEyeQ.

RESULTS

PedEyeQ domain scores were significantly worse with CEL compared with controls (p<0.01 for each), with the exception of the Proxy Social domain among children aged 0-4 years (p=0.283). Child PedEyeQ greatest differences were in the functional vision domain (5-11 years, -20 points (95% CI -27 to -12)) and frustration/worry domain (12-17 years, -41 (95% CI -37 to -6)). Proxy PedEyeQ greatest differences were in the functional vision domain (0-4 years, -34 (95% CI -45 to -22)) and frustration/worry domain (5-11 years, -27 (95% CI -39 to -14); 12-17 years, -37(95% CI (-48 to -26))). Parent PedEyeQ greatest difference was in the 'worry about child's eye condition' (-57 (95% CI (-63 to -51))).

CONCLUSIONS

In this study, children with CEL had reduced functional vision and ER-QOL compared with controls. Parents of children with CEL also experience reduced quality of life.

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.

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.

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.

The Myopic Shift in Aphakic Eyes in the Infant Aphakia Treatment Study After 10 Years of Follow-up

OBJECTIVES

To report the myopic shift in the aphakic eyes of a cohort of children who underwent unilateral cataract surgery during infancy and were then followed longitudinally for 10.5 years.

METHODS

One-half of the children enrolled in the Infant Aphakia Treatment Study (IATS) were randomized to aphakia and contact lens correction after unilateral cataract surgery. They then underwent ocular examinations using standardized protocols at prescribed time intervals until age 10.5 years.

RESULTS

Thirty of 57 children randomized to aphakia remained aphakic at age 10.5, having undergone unilateral cataract surgery at a median age of 1.6 (IQR: 1.1-3.1) months. The median refractive error (RE) in the 57 eyes randomized to aphakia immediately after cataract surgery was 19.01 D (IQR: 16.98-20.49) compared to 10.38 D (IQR: 7.50-14.00) for the 30 eyes that remained aphakic at age 10.5 years. The mean change in RE in aphakic eyes was -2.11 D/year up to age 1.5 years, -0.68 D/year from 1.5 to 5.0 years, and -0.35 D/year from age 5 to 10.5 years. At age 10.5 years, 18 patients continued to wear a contact lens correction (silicone elastomer, n=6; gas permeable, n=6; hydrogel, n=5; and silicone hydrogel, n=1) (median RE, 12.50 D), 9 wore only spectacles (median RE, 4.00 D), and 4 wore no correction (median RE, 11.25 D) to correct their aphakic eye.

CONCLUSIONS

The RE in aphakic eyes decreased by 44% from infancy to age 10.5 years. About two-thirds of children who remained aphakic at age 10.5 years continued to wear a contact lens.

Effect of Age at Primary Intraocular Lens Implantation on Refractive Growth in Young Children

PURPOSE

To evaluate the effect of age at primary intraocular lens (IOL) implantation on rate of refractive growth (RRG3) during childhood.

METHODS

A retrospective chart review was performed for children undergoing primary IOL implantation during cataract surgery. RRG3 was calculated for one eye from each patient using the first postoperative refraction, last refraction that remained stable (< 1.00 diopters [D] change/2 years), and the corresponding ages. RRG3 values for pseudophakic patients operated on from ages 0 to 5 months were compared with values for patients operated on at ages 6 to 23 months and 24 to 72 months. Patients with refractive errors that stabilized were grouped by age at surgery to compare age at refractive plateau.

RESULTS

Of 296 eyes identified from 219 patients, 46 eyes met the inclusion criteria. There was a statistically significant difference in RRG3 among age groups. The mean RRG3 value was -19.82 ± 5.23 D for the 0 to 5 months group, -22.32 ± 7.45 D for the 6 to 23 months group (0 to 5 months vs 6 to 23 months, P = .43), and -9.64 ± 11.95 D for the 24 to 72 months group (0 to 5 months vs 24 to 72 months, P = .01).

CONCLUSIONS

Age at primary IOL implantation affects the RRG3, especially for children 0 to 23 months old at surgery. Surgeons performing primary IOL implantation in infants may want to use age-adjusted assumptions, because faster refractive growth rates can be expected in young children. [J Pediatr Ophthalmol Strabismus. 2020;57(4):264-270.].

Accuracy of 8 intraocular lens power calculation formulas in pediatric cataract patients

PURPOSE

To compare the accuracy of the eight formulas for intraocular lens (IOL) power calculation in pediatric cataract patients.

METHODS

A retrospective study. A total of 68 eyes (68 patients) that underwent uneventful cataract surgery and posterior chamber IOL implantation in the capsular bag were enrolled. We compared the calculation accuracy of the 8 formulas at 1 month postoperatively and performed subgroup analysis according to age or axial length (AL).

RESULTS

The mean age at surgery was 34.07 ± 24.60 months and mean AL was 21.12 ± 1.42 mm. The mean prediction errors (PE) of eight formulas for all patients were as follows: SRK II (- 0.66), SRK/T (- 0.44), Holladay 1 (- 0.36), Hoffer Q (- 0.09), Olsen (0.71), Barrett (0.37), Holladay 2 (- 0.70), and Haigis (0.50). There was significant difference among the 8 formulas (p < 0.0001), while no significant difference of absolute PE was found among the 8 formulas in all patients (p = 0.053). Moreover, in patients younger than 2 years old or with AL ≤ 21 mm, SRK/T formula was relatively accurate in 34% and 39% of eyes, respectively. While in patients older than 2 or with AL > 21 mm, Barrett and Haigis formulas were better (58% and 47% for Barrett, 52% and 53% for Haigis).

CONCLUSION

Overall, in patients younger than 2 years old or with AL ≤ 21 mm, SRK/T formulas were relatively accurate, while Barrett and Haigis formulas were better in patients older than 2 or with AL > 21 mm.

Dynamic profile of ocular refraction in pediatric cataract patients after lens surgeries

AIM

To study the change in ocular refraction in patients with pediatric cataracts (PCs) after lens extraction.

METHODS

A total of 1258 patients who were undergoing cataract extraction with/without intraocular lens (IOL) implantation were recruited during preoperative examinations between Jan 2010 and Oct 2013. Patient ages ranged from 1.5mo to 14y. Follow-ups were conducted at 1wk, 1, and 3mo postoperatively and every 3mo in the first year, then 6mo thereafter. Ocular refraction [evaluated as spherical equivalent (SE)] and yearly myopic shift (YMS) were recorded and statistically analyzed among patients with age at surgery, baseline ocular refraction, gender, postoperative time and laterality (bilateral vs unilateral).

RESULTS

By Dec 31^st 2015, 1172 participants had been followed for more than 2y. The median follow-up period was 3y. The critical factors affecting the ocular refraction of PC patients were baseline ocular refraction, postoperative time for both aphakic and pseudophakic eyes. YMS grew most rapidly in young childhood and early adolescence.

CONCLUSION

After lens surgeries, ocular refraction in PC patients shows an individual difference of change. Further concerns should be raising to monitor the rapid myopic shift at early adolescence of these patients.

Outcomes of Bilateral Cataracts Removed in Infants 1 to 7 Months of Age Using the Toddler Aphakia and Pseudophakia Treatment Study Registry

PURPOSE

To evaluate outcomes of bilateral cataract surgery in infants 1 to 7 months of age performed by Infant Aphakia Treatment Study (IATS) investigators during IATS recruitment and to compare them with IATS unilateral outcomes.

DESIGN

Retrospective case series review at 10 IATS sites.

PARTICIPANTS

The Toddler Aphakia and Pseudophakia Study (TAPS) is a registry of children treated by surgeons who participated in the IATS.

METHODS

Children underwent bilateral cataract surgery with or without intraocular lens (IOL) placement during IATS enrollment years 2004 through 2010.

MAIN OUTCOME MEASURES

Visual acuity (VA), strabismus, adverse events (AEs), and reoperations.

RESULTS

One hundred seventy-eight eyes (96 children) were identified with a median age of 2.5 months (range, 1-7 months) at the time of cataract surgery. Forty-two eyes (24%) received primary IOL implantation. Median VA of the better-seeing eye at final study visit closest to 5 years of age with optotype VA testing was 0.35 logarithm of the minimum angle of resolution (logMAR; optotype equivalent, 20/45; range, 0.00-1.18 logMAR) in both aphakic and pseudophakic children. Corrected VA was excellent (<20/40) in 29% of better-seeing eyes, 15% of worse-seeing eyes. One percent showed poor acuity (≥20/200) in the better-seeing eye, 12% in the worse-seeing eye. Younger age at surgery and smaller (<9.5 mm) corneal diameter at surgery conferred an increased risk for glaucoma or glaucoma suspect designation (younger age: odds ratio [OR], 1.44; P = 0.037; and smaller cornea: OR, 3.95; P = 0.045). Adverse events also were associated with these 2 variables on multivariate analysis (younger age: OR, 1.36; P = 0.023; and smaller cornea: OR, 4.78; P = 0.057). Visual axis opacification was more common in pseudophakic (32%) than aphakic (8%) eyes (P = 0.009). Unplanned intraocular reoperation occurred in 28% of first enrolled eyes (including glaucoma surgery in 10%).

CONCLUSIONS

Visual acuity after bilateral cataract surgery in infants younger than 7 months is good, despite frequent systemic and ocular comorbidities. Although aphakia management did not affect VA outcome or AE incidence, IOL placement increased the risk of visual axis opacification. Adverse events and glaucoma correlated with a younger age at surgery and glaucoma correlated with the presence of microcornea.

Ocular Component Development during Infancy and Early Childhood

SIGNIFICANCE

The study fills an important gap by providing a longitudinal description of development of the major structural and optical components of the human eye from 3 months to nearly 7 years of age. Normative development data may provide insights into mechanisms for emmetropization and guidance on intraocular lens power calculation.

PURPOSE

The purpose of this study was to describe the pattern of development of refractive error and the ocular components from infancy through early childhood.

METHODS

Cycloplegic retinoscopy (cyclopentolate 1%), keratophakometry, and ultrasonography were performed longitudinally on between 162 and 293 normal birth weight infants at 0.25, 0.75, 1.5, 3, 4.5, and 6.5 years of age.

RESULTS

Refractive error and most ocular components displayed an early exponential phase of rapid development during the first 1 to 2 years of life followed by a slower quadratic phase. Anterior and vitreous chamber depths, axial length, and crystalline lens radii increased at every visit. The crystalline lens thinned throughout the ages studied. The power of the cornea showed an early decrease, then stabilized, whereas the crystalline lens showed more robust decreases in power. The crystalline lens refractive index followed a polynomial growth and decay model, with an early increase followed by a decrease starting at 1 to 2 years of age. Refractive error became less hyperopic and then was relatively stable after 1 to 2 years of age. Axial lengths increased by 3.35 ± 0.64 mm between ages 0.25 and 6.5 years, showed uniform rates of growth across the range of initial values, and were correlated with initial axial lengths (r = 0.44, P < .001).

CONCLUSIONS

Early ocular optical and structural development appears to be biphasic, with emmetropization occurring within the first 2 years of infancy during a rapid exponential phase. A more stable refractive error follows during a slower quadratic phase of growth when axial elongation is compensated primarily by changes in crystalline lens power.

Axial length development in children

AIM

To study ocular axial lengths in pediatric subjects without intraocular pathology.

METHODS

An Institutional Review Board-approved consecutive retrospective chart review of axial lengths measured in pediatric subjects who underwent examination under anesthesia due to positive family history of retinoblastoma or other inherited ocular disease. Only subjects without any intraocular pathology in either eye were included. Subjects were stratified into age groups. An axial length model using a logarithmic regression algorithm was calculated.

RESULTS

Data from 330 eyes of 165 subjects were included in the study. The mean age at the time of examination was 30.62 (SD 18.04)mo. The steepest increase in axial length was present during the first 10mo of life. After 36mo, there was no statistically significant axial length growth.

CONCLUSION

This study presents the biggest series of pediatric axial lengths in healthy eyes. The axial length model developed with these data may assist in the diagnosis and management of a wide variety of pediatric ophthalmic diseases.

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.

Study of Feasibility and Safety of Higher-Dose Dexmedetomidine in Special Outpatient Examination of Pediatric Ophthalmology

Objective

To investigate the feasibility and safety of higher-dose dexmedetomidine in ophthalmological outpatient examination of children with cataract.

Methods

100 cases of children were recruited in the study and randomly equally divided into two groups. One group was given 2 μg/kg intranasal dexmedetomidine anesthesia, while the other group was under 3 μg/kg. The dosage of dexmedetomidine was calculated by the same anesthesiologist according to the weight of patient. After sufficient sedation, the same ophthalmologist performed ocular examinations manually, including intraocular pressure, keratometry, axial length, and corneal thickness and recorded the ocular position score during intraocular pressure measurement and corneal thickness measurement. Other variables were sedation onset time, recovery time, vital signs, and side effects.

Results

In intraocular pressure measurement, only one case in the 2 μg/kg group did not complete the examination, while all cases in the 3 μg/kg group completed the examination and the difference of the success rate between the two groups was nonsignificant (P > 0.05). The success rates of the 3 μg/kg group in corneal curvature, axial length, and corneal thickness examination were 96%, 92%, and 86%, respectively, which were significantly higher than those of the 2 μg/kg group (22%, 18%, and 4%). The average onset time of sedation in the 3 μg/kg group was 15.42 ± 2.09 minutes, which was significantly shorter than that in the 2 μg/kg group (19.52 ± 2.43 minutes, P < 0.001). The average time of completing all examinations in the 3 μg/kg group was 18.36 ± 4.01 minutes, which was significantly shorter than that in the 2 μg/kg group (22.62 ± 4.13 min, P < 0.001). The recovery time of group 3 μg/kg was 90.62 ± 27.80 min, which was significantly longer than that of group 2 μg/kg (49.20 ± 15.50 min). Vital signs such as pulse, blood pressure, oxygen saturation, and heart rate kept in normal range throughout the tests, and no obvious side effects were observed.

Conclusion

3 μg/kg intranasal dexmedetomidine had a higher sedation success rate and quality than 2 μg/kg did in pediatric ocular examinations, without any obvious side effects.

Predicting Factor of Visual Outcome in Unilateral Idiopathic Cataract Surgery in Patients Aged 3 to 10 Years

Purpose

To report the surgical results of unilateral pediatric cataracts from uncertain causes in relatively older children and to identify factors related to better visual outcomes.

Methods

We retrospectively evaluated the medical records of 39 patients who underwent surgery between the ages of 3 and 10 years for unilateral pediatric cataracts of no known cause. All patients underwent primary intraocular lens implantation and postoperative amblyopia treatment. A postoperative final visual acuity better than 20 / 30 was considered to be a good visual outcome.

Results

The mean age of patients was 6.0 ± 1.8 years at the time of surgery. The mean preoperative visual acuity was 1.07 ± 0.71 logarithm of the minimum angle of resolution (range, 0.15 to 3.00), while the mean final postoperative visual acuity was 0.47 ± 0.54 logarithm of the minimum angle of resolution (range, 0.00 to 2.00). Of 39 patients, 18 (46.2%) achieved a good visual outcome. Only the preoperative visual acuity maintained a significant association with a good visual outcome according to our multivariate analysis (p = 0.040). A preoperative visual acuity of 20 / 100 or better was found to increase the chance of achieving a good visual outcome by 13.79-fold (95% confidence interval, 1.13 to 167.58).

Conclusions

The visual outcome of unilateral pediatric cataract surgery for cataracts with no specific cause identified in patients after three years of age could be satisfactory, especially with a preoperative visual acuity of 20 / 100 or better.

Long-term Results in Pediatric Developmental Cataract Surgery with Primary Intraocular Lens Implantation

OBJECTIVES

The aim of this study was to evaluate the outcomes of pediatric developmental cataract surgery with primary intraocular lens (IOL) implantation.

MATERIALS AND METHODS

Patients between 2 and 16 years old who underwent cataract surgery with primary IOL implantation were retrospectively evaluated. Age at time of surgery, pre- and postoperative best corrected visual acuities, postoperative ocular complications, and any accompanying ocular pathologies were obtained from the patients' charts. Mean refractive changes and degree of myopic shift were analyzed according to the age groups. Operated eyes were also compared with the fellow eyes in unilateral cases.

RESULTS

A total of 101 eyes of 65 patients were included. The average age at time of surgery was 76±40 months and the average follow-up period was 44±30 months. Among the 78 eyes that could be assessed for visual acuity improvement, 66 (84.6%) of them showed ≥2 lines of improvement. The difference in the mean refractive change between the 2-5 years old and 8-16 years old age groups was found to be statistically significant. However, the mean refractive change per year was not found to be significant between the same age groups. In unilateral cases, the operated eyes showed a greater myopic change than the fellow eyes, with no statistically significant difference. The most common postoperative complication was visual axis opacity.

CONCLUSION

Good visual outcomes can be achieved following pediatric cataract surgery with primary IOL implantation. Optic axis opacities were the most common postoperative complications. Overall, refractive changes following surgery are inevitable, and more prominent in younger age groups.

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

PURPOSE

To report the prevalence of anisometropia at age 5 years after unilateral intraocular lens (IOL) implantation in infants.

DESIGN

Prospective randomized clinical trial.

METHODS

Fifty-seven infants in the Infant Aphakia Treatment Study (IATS) with a unilateral cataract were randomized to IOL implantation with an initial targeted postoperative refractive error of either +8 diopters (D) (infants 28 to <48 days of age) or +6 D (infants 48-210 days of age). Anisometropia was calculated at age 5 years. Six patients were excluded from the analyses.

RESULTS

Median age at cataract surgery was 2.2 months (interquartile range [IQR], 1.2, 3.5 months). The mean age at the age 5 years follow-up visit was 5.0 ± 0.1 years (range, 4.9-5.4 years). The median refractive error at the age 5 years visit of the treated eyes was -2.25 D (IQR -5.13, +0.88 D) and of the fellow eyes +1.50 D (IQR +0.88, +2.25). Median anisometropia was -3.50 D (IQR -8.25, -0.88 D); range -19.63 to +2.75 D. Patients with glaucoma in the treated eye (n = 9) had greater anisometropia (glaucoma, median -8.25 D; IQR -11.38, -5.25 D vs no glaucoma median -2.75; IQR -6.38, -0.75 D; P = .005).

CONCLUSIONS

The majority of pseudophakic eyes had significant anisometropia at age 5 years. Anisometropia was greater in patients that developed glaucoma. Variability in eye growth and myopic shift continue to make refractive outcomes challenging for IOL implantation during infancy.

Distribution of axial length in Chinese congenital ectopia lentis patients: a retrospective study

BACKGROUND

Congenital ectopia lentis (CEL) usually leads to refractive error and may influence the axial length development. But few investigations have reported patient demographics and the distribution of axial length (AL) before surgery in Chinese pediatric patients with CEL. To describe the distribution of AL before surgery in CEL patients and its relationship with patients' demographics, such as age, Marfan syndrome, sex, and laterality.

METHODS

This retrospective study reviewed 306 CEL patients from January 1, 2006 to December 31, 2015. One eye was randomly selected from each patient if both eyes were EL. The influences of Marfan syndrome, sex, and laterality to AL in different age subgroups were evaluated and compared. The differences of the AL between groups were assessed using the student t test or paired t-test. P-values less than 0.05 were considered statistically significant.

RESULTS

Two hundred forty-seven eyes were enrolled. 58.3% of all the patients had binoculus EL, 70% of all the patients were male and 36% of all the patients were diagnosed with Marfan syndrome. The mean AL of EL patients was 25.1 ± 2.5 mm. There was no statistical difference in the AL between patients with and without Marfan syndrome, and in the AL between male and female patients. There was statistical difference in AL between the EL-affected eye and the unaffected eye in monocular EL patients younger than 12 years old.

CONCLUSIONS

This study suggests that AL can be influenced by CEL, but the influence of CEL may be reduced after the age of 12 years old, which will likely provide a useful reference when considering the most appropriate time of surgery.

Long-term Outcomes of Primary Intraocular Lens Implantation in Patients Aged 7 to 24 Months

PURPOSE

To report long-term outcomes of primary intraocular lens (IOL) placement in patients aged 7 to 24 months.

METHODS

This was a retrospective study of 27 consecutive patients (28 eyes) aged 7 to 24 months who underwent cataract surgery with primary IOL placement.

RESULTS

Average follow-up was 62.7 ± 41.7 months and the mean age of surgery was 14.4 ± 5.6 months. Mean final visual acuity was 1.02 ± 0.72 logMAR (20/209). Adverse events occurred in 7 eyes (25%) and included visual axis opacification in 6 eyes and pupillary block glaucoma in 1 eye. Seven patients (25.9%) required additional intraocular surgery. Strabismus was present in 19 patients (70.4%). Better stereopsis was correlated with better final acuity.

CONCLUSIONS

Cataract surgery with IOL placement in patients aged 7 to 24 months is associated with few complications. Visual axis opacification is the most frequent adverse event. [J Pediatr Ophthalmol Strabismus. 2017;54(3):149-155.].

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

PURPOSE

To report the myopic shift at 5 years of age after cataract surgery with intraocular lens (IOL) implantation for infants enrolled in the Infant Aphakia Treatment Study (IATS).

METHODS

Refractions were performed at 1 month and every 3 months postoperatively until age 4 years and then at ages 4.25, 4.5, and 5 years. The change in refraction over time was estimated by linear mixed model analysis.

RESULTS

Intraocular lens implantation was completed in 56 eyes; 43 were analyzed (median age, 2.4 months; range, 1.0-6.8 months). Exclusions included 11 patients with glaucoma, 1 patient with Stickler syndrome, and 1 patient with an IOL exchange at 8 months postoperatively. The mean rate of change in a myopic direction from 1 month after cataract surgery to age 1.5 years was 0.35 diopters (D)/month (95% confidence interval [CI], 0.29-0.40 D/month); after age 1.5 years, the mean rate of change in a myopic direction was 0.97 D/year (95% CI, 0.66-1.28 D/year). The mean refractive change was 8.97 D (95% CI, 7.25-10.68 D) at age 5 years for children 1 month of age at surgery and 7.22 D (95% CI, 5.54-8.91 D) for children 6 months of age at surgery. The mean refractive error at age 5 years was -2.53 D (95% CI, -4.05 to -1.02).

CONCLUSIONS

After IOL implantation during infancy, the rate of myopic shift occurs most rapidly during the first 1.5 years of life. Myopic shift varies substantially among patients. If the goal is emmetropia at age 5 years, then the immediate postoperative hypermetropic targets should be +10.5 D at 4 to 6 weeks and +8.50 D from 7 weeks to 6 months. However, even using these targets, it is likely that many children will require additional refractive correction given the high variability of refractive outcomes.

Cataract surgery in children with retinopathy of prematurity (ROP): surgical outcomes

PURPOSE

To report the outcomes of cataract surgery in children with retinopathy of prematurity (ROP).

METHODS

A retrospective case review of all children diagnosed with ROP from January 2001 to December 2014 was done and those who underwent cataract surgery were included in the study. Details of ROP and cataract treatment, postoperative complications and outcomes were analysed.

RESULTS

Of the 2258 children diagnosed to have ROP, 28 eyes of 22 children were included, 14 boys and 8 girls. Mean age at cataract surgery was 18.9 months (range 2 months to 12 years). Most common grade of ROP was stage 4 (13 eyes). Nineteen eyes underwent retinal surgery, scleral buckle (one eye) and laser (three eyes). Five eyes showed spontaneous regression. Mean duration for the development of cataract postretinal surgery was 7.76 months (range 2-32 months). Nine eyes did not receive a primary intraocular lens (IOL). Intraoperative posterior capsular rupture occurred in two eyes. Postoperative complications included visual axis opacification (four), secondary glaucoma (two) and IOL capture (one). Postoperative visual acuity assessment was possible in 23 eyes, 11 had better than 20/200 vision. Eleven patients had a follow-up of at least 2 years and the mean myopic shift at 2 years was -3.07 D in pseudophakes and -8.75 D in aphakes.

CONCLUSIONS

Cataracts may develop in children with ROP regardless of the modality of intervention. Postoperative complications and refractive changes are similar to those in eyes without ROP.

Comparison of the rate of refractive growth in aphakic eyes versus pseudophakic eyes in the Infant Aphakia Treatment Study

PURPOSE

To compare the rate of refractive growth (RRG) between aphakic eyes and pseudophakic eyes in the Infant Aphakia Treatment Study (IATS).

SETTING

Twelve clinical sites across the United States.

DESIGN

Randomized clinical trial.

METHODS

Patients randomized to unilateral cataract extraction with contact lens correction versus intraocular lens (IOL) implantation in the IATS had their rate of refractive growth (RRG3) calculated based on the change in refraction from the 1-month postoperative examination to age 5 years. The RRG3 is a logarithmic formula designed to calculate the RRG in children. Two-group t tests were used to compare the mean refractive growth between the contact lens group and IOL group and outcomes based on age at surgery and visual acuity.

RESULTS

Longitudinal refractive data were studied for 108 of 114 patients enrolled in the IATS (contact lens group, n = 54; IOL group, n = 54). The mean RRG3 was similar in the contact lens group (-18.0 diopter [D] ± 11.0 [SD]) and the IOL group (-19.0 ± 9.0 D) (P = .49). The RRG3 value was not correlated with age at cataract surgery, glaucoma status, or visual outcome in the IOL group. In the aphakia group, only visual outcome was correlated with refractive growth (P = .01).

CONCLUSIONS

Infants' eyes had a similar rate of refractive growth after unilateral cataract surgery whether or not an IOL was implanted. A worse visual outcome was associated with a higher RRG in aphakic, but not pseudophakic, eyes.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

The change in axial length in the pseudophakic eye compared to the unoperated fellow eye in children with bilateral cataracts

PURPOSE

To compare the change in ocular axial length of the pseudophakic eye versus the fellow eye in children with bilateral cataracts who had surgery in only one eye.

METHODS

In this prospective cohort study, 50 eyes of 25 children with bilateral lamellar cataracts were analyzed. A complete ophthalmic examination and evaluation of axial length measurements by contact ultrasound biometry were performed in all eyes undergoing cataract surgery with IOL implantation and in contralateral eyes. The primary outcome measure was the percentage rate of growth between the final and initial measurements, defined as the initial minus the final measurement, with the difference being divided by the initial measurement and the result multiplied by 100.

RESULTS

Children aged 4-10 years of age were followed for a mean of 28.5 months. The values for axial length percentage rate of growth were significantly lower in pseudophakic eyes than in the unoperated, contralateral eyes (0.64% vs 2.09%, P < 0.05). Final visual acuity, follow-up time, and initial axial length did not affect the results. Pseudophakic eyes with posterior capsule opacification that underwent neodymium YAG laser showed a significantly higher rate of growth than unoperated eyes.

CONCLUSIONS

Axial length in children older than 4 years showed a trend toward stabilization, with lower changes in axial length measurements in pseudophakic eyes and a higher rate of axial growth in contralateral eyes.

A retinoscopic survey of 333 horses and ponies in the UK

INTRODUCTION

Ophthalmic examination in the horse is generally limited to crude assessment of vision and screening for ocular lesions. The refractive state of equine eyes and the potential impact on vision and performance requires further investigation.

OBJECTIVE

To assess the refractive state of a large, mixed-breed sample of horses and ponies in the United Kingdom (UK).

PROCEDURE

The refractive state of both eyes of 333 horses and ponies was determined by streak retinoscopy, and the effect of age, height, gender, breed and management regime on the refractive state assessed.

RESULTS

Emmetropia was found in 557 of 666 (83.63%) of eyes; 228/333 (68.5%) of the horses/ponies were emmetropic in both eyes. Refractive errors of greater than 1.50 D (in either direction) were found in 2.7% of the eyes tested. Ametropic eyes included hyperopia (54%) and myopia (46%). Anisometropia was found in 30.3% of horses and ponies. Breed of horse/pony was the only factor that affected refractive state (in the left eye only, P < 0.05) with Thoroughbred crosses having a tendency toward myopia and Warmbloods/Shires toward hyperopia.

DISCUSSION AND CONCLUSION

The retinoscopic survey found emmetropia to be the predominant refractive state of the equine eye with no evidence of an overall trend toward myopia or hyperopia. However, individual and breed-related differences were found. Such factors should be considered in the selection of horses for sport and leisure, and when evaluating their performance potential. More comprehensive visual testing would be valuable in identifying underlying causes of behavioral problems.

Solutions in pediatric cataracts

PURPOSE OF REVIEW

Modern pediatric cataract surgical techniques combined with a greater understanding of the natural history of aphakia and pseudophakia have changed the approach to the surgery of pediatric cataracts.

RECENT FINDINGS

Advanced surgical techniques, new pharmacologic options and long-term refractive planning have improved surgical success.

SUMMARY

It is essential that the ophthalmic surgeon who cares for children with cataracts is aware of these issues.

Predictability of intraocular lens power calculation formulae in infantile eyes with unilateral congenital cataract: results from the Infant Aphakia Treatment Study

PURPOSE

To compare accuracy of intraocular lens (IOL) power calculation formulae in infantile eyes with primary IOL implantation.

DESIGN

Comparative case series.

METHODS

The Hoffer Q, Holladay 1, Holladay 2, Sanders-Retzlaff-Kraff (SRK) II, and Sanders-Retzlaff-Kraff theoretic (SRK/T) formulae were used to calculate predicted postoperative refraction for eyes that received primary IOL implantation in the Infant Aphakia Treatment Study. The protocol targeted postoperative hyperopia of +6.0 or +8.0 diopters (D). Eyes were excluded for invalid biometry, lack of refractive data at the specified postoperative visit, diagnosis of glaucoma or suspected glaucoma, or sulcus IOL placement. Actual refraction 1 month after surgery was converted to spherical equivalent and prediction error (predicted refraction - actual refraction) was calculated. Baseline characteristics were analyzed for effect on prediction error for each formula. The main outcome measure was absolute prediction error.

RESULTS

Forty-three eyes were studied; mean axial length was 18.1 ± 1.1 mm (in 23 eyes, it was <18.0 mm). Average age at surgery was 2.5 ± 1.5 months. Holladay 1 showed the lowest median absolute prediction error (1.2 D); a paired comparison of medians showed clinically similar results using the Holladay 1 and SRK/T formulae (median difference, 0.3 D). Comparison of the mean absolute prediction error showed the lowest values using the SRK/T formula (1.4 ± 1.1 D), followed by the Holladay 1 formula (1.7 ± 1.3 D). Calculations with an optimized constant showed the lowest values and no significant difference between the Holladay 1 and SRK/T formulae (median difference, 0.3 D). Eyes with globe AL of less than 18 mm had the largest mean and median prediction error and absolute prediction error, regardless of the formula used.

CONCLUSIONS

The Holladay 1 and SRK/T formulae gave equally good results and had the best predictive value for infant eyes.

[Evaluation of predictability and refractive changes in pediatric pseudophakia]

OBJECTIVE

Evaluate the predictability of the postoperative refraction and refractive changes in pediatric pseudophakia.

METHODS

Prospective, longitudinal follow-up on patients under the age of 15 years operated on for a cataract with intraocular lens, with 5 continuous years of follow-up. The patients were divided into 4 groups according to age at the time of the surgery: group from 0 to 2 years old, from 3 to 5 years old, from 6 to 8 years old, and 9 years and over. Error prediction and refractive change were studied. Statistical analysis was performed using the Student t and ANOVA test.

RESULTS

A total of 60 eyes were included (44 patients). No significant differences were found between the unilateral and bilateral group. The prediction error in the 0 to 2 years group was 1.5±1.8 D, significantly higher than in the other groups (ANOVA P=.01). Refractive change in 5 years of the group of 0 to 2 years was -4.7±3.4 D (ANOVA P=.0002), while in the other groups it was significantly lower, with no differences between them.

CONCLUSIONS

The 0 to 2 years group was less hyperopic than expected, 100% within the accepted of 2 standard deviations, but with a high variability. The refractive change observed in this group coincides with previous reports that the largest growth and increase in axial length occurs during the first 2 years. The calculation and use of an IOL in children has a better immediate refractive prediction, and at long term in those older than 2 years of age.

Reanalysis of refractive growth in pediatric pseudophakia and aphakia

BACKGROUND

The current model of refractive growth in children (RRG2) is calculated as the slope of aphakic refraction at the spectacle plane versus the logarithm of adjusted age. However, this model fails in infants because of the optical effect of vertex distance of a spectacle lens on the effective power at the cornea. In this study, we developed a new model of refractive growth (RRG3) that eliminates the optical effect of vertex distance on the RRG2 model.

METHODS

We calculated RRG3 values for pseudophakic and aphakic eyes previously analyzed for RRG2. Inclusion criteria were age ≤10 years at the time of cataract surgery and follow-up time between measured refractions of at least 3.6 years and at least the age at first refraction plus 0.6 years. For both pseudophakic and aphakic eyes, we compared RRG3 values in children who had cataract surgery before age 6 months with those in children aged 6 months or older.

RESULTS

A total of 78 pseudophakic and 70 aphakic eyes met the inclusion criteria. Ages at surgery ranged from 0.25 to 9 years, with a 9.5-year mean follow-up time. The mean RRG3 value was not significantly different between the surgical age groups for both pseudophakic eyes (P = 0.053) and aphakic eyes (P = 0.59).

CONCLUSIONS

The RRG3 values were not significantly different between the surgical age groups for both pseudophakic and aphakic eyes. Consequently, RRG3 is theoretically applicable even in the small eyes of infants having surgery before 6 months of age.

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.

Congenital and infantile cataract: aetiology and management

Congenital cataract is the commonest worldwide cause of lifelong visual loss in children. Although congenital cataracts have a diverse aetiology, in many children, a cause is not identified; however, autosomal dominant inheritance is commonly seen. Early diagnosis either on the post-natal ward or in the community is important because appropriate intervention can result in good levels of visual function. However, visual outcome is largely dependent on the timing of surgery when dense cataracts are present. Good outcomes have been reported in children undergoing surgery before 6 weeks of age in children with unilateral cataract and before 10 weeks of age in bilateral cases. Placement of an artificial intraocular lens implant after removal of the cataract has become established practice in children over 2 years of age. There remains debate over the safety and predictability of intraocular lens implantation in infants. Despite early surgery and aggressive optical rehabilitation, children may still develop deprivation amblyopia, nystagmus, strabismus, and glaucoma. The diagnosis and management of congenital cataracts has improved substantially over the past 30 years with a concurrent improvement in outcomes for affected children. Many aspects of the pre-, intra-, and postoperative management of these patients continue to be refined, highlighting the need for good quality data and prospective collaborative studies in this field.

Evolution of postoperative astigmatism after large incision PMMA lens implantation in children

PURPOSE

To investigate the evolution of postoperative astigmatism after cataract extraction and lens implantation in children through a 6.5 mm limbal incision.

METHODS

This is a retrospective longitudinal study of consecutive pediatric patients with adequate follow-up who underwent cataract extraction with intraocular lens implantation through a 6.5 mm limbal incision. Preoperative and 3-month postoperative astigmatism and spherical equivalent were compared.

RESULTS

A total of 92 eyes of 73 children met the inclusion criteria. The mean cylindrical correction on the first postoperative day was 6.6 ± 2.3 D (range, 1.00-13.00 D). This dropped to 1.9 ± 1.7 D between 2 and 4 weeks and 1.2 ± 1.0 D (range, 0-3.25 D) by 3 months postoperatively. The mean spherical equivalent was +0.5 D on the first postoperative day and did not change significantly during the follow-up period. The mean astigmatism preoperatively (1.2 ± 0.8 D) and 3 months postoperatively (1.2 ± 1.0 D) were not statistically different (p = 0.9). There was no statistically significant change in astigmatism between 1 and 3 months and 1 and 2 years (p = 0.16, n = 33).

CONCLUSIONS

Large cylindrical refractive errors after pediatric cataract surgery through a 6.5 mm limbal incision resolve postoperatively within 3 months.

Longitudinal change in aphakic refraction after early surgery for congenital cataract

PURPOSE

To characterize the longitudinal changes of refraction in aphakic eyes after early surgery for congenital cataract and to evaluate longitudinally measured aphakic refraction (individual vs group mean) as a noninvasive indicator of postoperative disturbances in ocular development.

METHODS

Records of children who had cataract surgery during their first year of life between 1980 and 1995 were obtained from a prospective, population-based study of congenital cataract. Only children with regular follow-up were included. Postoperative aphakic refraction was calculated at the corneal plane. Data were obtained up to 36 months of age.

RESULTS

The study included 28 children (49 eyes) who underwent surgery at a median age of 2.8 months (range, 0-9 months). The decrease of aphakic refraction at the corneal plane followed a logarithmic trend (R(2) = 0.95). A total of 36 eyes followed this pattern, with no growth in 8 eyes and an increased growth rate in 1 eye with uncontrolled glaucoma and 4 eyes of 2 children with Down syndrome.

CONCLUSIONS

Most aphakic eyes follow a predictable, logarithmic change in refraction in the first 3 years of life, Longitudinal monitoring of refraction may prove to be a useful, noninvasive screening method for early detection of disturbances in aphakic eye growth.

Axial length measurements by contact and immersion techniques in pediatric eyes with cataract

PURPOSE

To compare axial length measurements by contact and immersion techniques in pediatric cataractous eyes.

DESIGN

Prospective, comparative case series.

PARTICIPANTS

In this prospective study, 50 cataractous eyes of 50 children were enrolled. In bilateral cataract, only 1 eye was selected to avoid a correlation effect in statistical analyses.

METHODS

Axial length was measured by both contact and immersion techniques for all eyes, randomized as to which to perform first to avoid measurement bias.

MAIN OUTCOME MEASURES

Axial length measured by contact and immersion techniques and the difference between contact and immersion technique axial length measurements.

RESULTS

Mean age±standard deviation at cataract surgery and at axial length measurement was 3.87±3.72 years. Axial length measurement by contact technique was significantly shorter as compared with immersion technique (21.36±3.04 mm and 21.63±3.09 mm, respectively; P<0.001). Axial length measurements using the contact technique were on an average 0.27 mm shorter than those obtained using the immersion technique. Forty-two eyes (84%) had shorter axial length when measured using the contact technique as compared with the immersion technique. Lens thickness measurement by contact technique was not significantly different from that of immersion technique (3.61±0.74 and 3.60±0.67 mm, respectively; P = 0.673). Anterior chamber depth measurement was significantly more shallow with the contact technique (3.39±0.59 mm and 3.69±0.54 mm, respectively; P<0.001). Intraocular lens power needed for emmetropia was significantly different (28.68 diopters [D] vs. 27.63 D; P<0.001).

CONCLUSIONS

Contact A-scan measurements yielded shorter axial length than immersion A-scan measurements. This difference was mainly the result of the anterior chamber depth rather than the lens thickness value. During intraocular lens (IOL) power calculation, if axial length measured by contact technique is used, 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.

Prediction error and accuracy of intraocular lens power calculation in pediatric patient comparing SRK II and Pediatric IOL Calculator

Background

Despite growing number of intraocular lens power calculation formulas, there is no evidence that these formulas have good predictive accuracy in pediatric, whose eyes are still undergoing rapid growth and refractive changes. This study is intended to compare the prediction error and the accuracy of predictability of intraocular lens power calculation in pediatric patients at 3 month post cataract surgery with primary implantation of an intraocular lens using SRK II versus Pediatric IOL Calculator for pediatric intraocular lens calculation. Pediatric IOL Calculator is a modification of SRK II using Holladay algorithm. This program attempts to predict the refraction of a pseudophakic child as he grows, using a Holladay algorithm model. This model is based on refraction measurements of pediatric aphakic eyes. Pediatric IOL Calculator uses computer software for intraocular lens calculation.

Methods

This comparative study consists of 31 eyes (24 patients) that successfully underwent cataract surgery and intraocular lens implantations. All patients were 12 years old and below (range: 4 months to 12 years old). Patients were randomized into 2 groups; SRK II group and Pediatric IOL Calculator group using envelope technique sampling procedure. Intraocular lens power calculations were made using either SRK II or Pediatric IOL Calculator for pediatric intraocular lens calculation based on the printed technique selected for every patient. Thirteen patients were assigned for SRK II group and another 11 patients for Pediatric IOL Calculator group. For SRK II group, the predicted postoperative refraction is based on the patient's axial length and is aimed for emmetropic at the time of surgery. However for Pediatric IOL Calculator group, the predicted postoperative refraction is aimed for emmetropic spherical equivalent at age 2 years old. The postoperative refractive outcome was taken as the spherical equivalent of the refraction at 3 month postoperative follow-up. The data were analysed to compare the mean prediction error and the accuracy of predictability of intraocular lens power calculation between SRK II and Pediatric IOL Calculator.

Results

There were 16 eyes in SRK II group and 15 eyes in Pediatric IOL Calculator group. The mean prediction error in the SRK II group was 1.03 D (SD, 0.69 D) while in Pediatric IOL Calculator group was 1.14 D (SD, 1.19 D). The SRK II group showed lower prediction error of 0.11 D compared to Pediatric IOL Calculator group, but this was not statistically significant (p = 0.74). There were 3 eyes (18.75%) in SRK II group achieved acccurate predictability where the refraction postoperatively was within ± 0.5 D from predicted refraction compared to 7 eyes (46.67%) in the Pediatric IOL Calculator group. However the difference of the accuracy of predictability of postoperative refraction between the two formulas was also not statistically significant (p = 0.097).

Conclusions

The prediction error and the accuracy of predictability of postoperative refraction in pediatric cataract surgery are comparable between SRK II and Pediatric IOL Calculator. The existence of the Pediatric IOL Calculator provides an alternative to the ophthalmologist for intraocular lens calculation in pediatric patients. Relatively small sample size and unequal distribution of patients especially the younger children (less than 3 years) with a short time follow-up (3 months), considering spherical equivalent only.

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.

Advances in the management of congenital and infantile cataract

Congenital and infantile cataracts produce deprivation amblyopia and can thus cause lifelong visual impairment. Successful management is dependent on early diagnosis and referral for surgery when indicated. Accurate optical rehabilitation and postoperative supervision are essential.The timing of surgery and its relationship to the duration of deprivation is important. Unilateral congenital cataract surgery within 6 weeks of birth produces the best outcomes. The equivalent 'latent' period for bilateral visual deprivation may be longer at around 10 weeks. Visual deprivation has a significant impact on the development of fixation stability. Major form deprivation, even after early surgery, leads to nystagmus. This is mostly manifest latent nystagmus (MLN). The latent period for fixation stability may be as short as 3 weeks. Preoperative congenital nystagmus (CN) can convert to more benign MLN after surgery. Infantile IOL implantation is becoming increasingly accepted. A satisfactory long-term refractive result requires that allowance be made for childhood axial growth and myopic shift. In a series of 25 infants (33 eyes) implanted before 12 months of age, the mean myopic shift at 12 months was 4.83 D. This increased to 5.3 D in infants implanted before 10 weeks. The initial desired refractive outcome following IOL implantation is thus hypermetropia, with the degree dependent on the age of the child. Glaucoma or ocular hypertension is a common complication following paediatric cataract surgery. Microphthalmia and surgery in early infancy are risk factors. Tonometry results may be influenced by the increased corneal thickness seen in aphakic and pseudophakic children. The long-term prognosis of eyes with aphakic glaucoma is not necessarily poor but intraocular pressure control may require three or more medications. Surgical intervention appears to be necessary in over a quarter of eyes. Posterior capsule opacification (PCO) is common in infants undergoing primary lens implantation. Primary capsulotomy and anterior vitrectomy reduce the risk of PCO. In the absence of anterior vitrectomy, primary posterior capsulotomy does not prevent visual axis opacification. Further developments will continue to be driven by clinical research. The prevention of capsule opacification and cellular proliferation may in future be achieved by the use of devices to specifically target epithelial cells at surgery.

Changes in interocular axial length after pediatric cataract surgery

PURPOSE

To explore the hypothesis that preoperative interocular axial length difference changes after pediatric cataract intraocular lens implantation surgery to meet the measurement of the fellow eye.

METHODS

Retrospective chart review. Eyes with traumatic and secondary cataract, lens subluxation, or postoperative glaucoma were excluded. In bilateral cataract cases, only right eye data were included. In addition, eyes were included only if axial length data for both eyes were available before surgery and at follow-up equal to or greater than the age at surgery.

RESULTS

Forty-seven eyes fit the inclusion criteria. Average age at surgery and follow-up was 2.2 +/- 2.2 and 5.6 +/- 2.9 years, respectively. Three groups were formed based on the preoperative interocular axial length difference: < -0.2, group 1; >or= -0.2, and <or=0.2, group 2; >0.2, group 3. Average age at surgery between these three groups was not significantly different (p = 0.82), nor was age at follow-up between the groups (p = 0.66). The change in interocular axial length difference (postoperative interocular axial length difference minus preoperative interocular axial length difference) was significant between the three groups (0.3, 0.2, -0.4 mm, respectively; p = 0.02). The average rate of axial length growth was significantly different between three groups (3.7, 2.4, 2.5 mm, respectively; p = 0.03).

CONCLUSIONS

Eyes with a shorter axial length than the fellow eye showed postoperative rate of axial growth that exceeded the growth rate of eyes with a longer interocular axial length. These growth rates resulted in a postoperative trend of intraocular axial length difference toward zero.

Paediatric pseudophakia: analysis of intraocular lens power and myopic shift

BACKGROUND

At the Alberta Children's Hospital, the authors have been performing paediatric cataract extraction with intraocular lens (IOL) implant for over 10 years. The authors examined the amount of myopic shift that occurs in various age groups and cataract types, in order to evaluate the success of predicting the appropriate power of IOL to implant.

METHODS

This study is a retrospective review children undergoing small incision posterior chamber foldable IOL implantation between age 1 month and 18 years, from 1995 to 2005. 163 eyes of 126 patients underwent surgery. All patients were followed for a minimum of 6 months postoperatively. The children were divided into four groups at time of surgery: Group A: 1-24 months, Group B: 25-48 months, Group C: 49-84 months, Group D: 85 months-18 years.

RESULTS

The mean target refraction for the groups were: Group A: +6.37 D, Group B: +4.66 D, Group C: +1.95 D, and Group D: +0.97 D. Children under 4 years experienced the most myopic shift and the largest mean rate of refractive change per year. Mean change Group A: -5.43 D, Group B: -4.16 D, Group C: -1.58 D, Group D: -0.71 D. Eighty-nine per cent of patients with unilateral cataracts had a postoperative refraction within 3.00 D of the fellow eye at last follow-up visit (mean=3.16 years).

CONCLUSIONS

The rate of myopic shift is high in children under age 4 years at time of surgery, shifting as much as -12.00 D. The mean postoperative target refraction should probably be increased from previous literature recommendations. The patient's age at time of cataract surgery and the refractive power of fellow eye are all factors to consider when deciding what power IOL to surgically implant in a paediatric patient.