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

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.

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.

Refractive outcomes after primary intraocular lens implantation in infants

BACKGROUND

Intraocular lens (IOL) implantation is becoming increasingly accepted as a primary procedure in infants.

AIM

To evaluate the accuracy of IOL power calculation, the rate of myopic shift and the refractive outcome after primary IOL implantation in infants aged <12 months at the time of cataract surgery.

METHOD

A retrospective case review of 25 patients (8 with bilateral cataracts and 17 with unilateral cataracts) who underwent cataract surgery with primary IOL implantation at <12 months of age. Outcomes measured were actual early postoperative refraction, lens power calculation error, myopic shift and refractive outcome.

RESULTS

In 83% of cases, actual postoperative refraction was within 2 dioptres (D) of the target refraction. Lens power calculation error did not depend on axial length, age at surgery or target refraction. Mean (SD) myopic shift was 5.43 (3.7) D in the first 12 months after surgery, but was significantly greater when surgery was performed at <10 weeks of age.

CONCLUSION

This study demonstrates that IOL power can be calculated with reasonable accuracy in infants using current formulas. Factors such as age at the time of surgery, axial length, whether surgery is unilateral or bilateral, and the presence of systemic pathologies do not seem to influence the accuracy of lens power calculation or myopic shift up to 36 months of age.

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

Long-term refractive change after intraocular lens implantation in childhood

BACKGROUND

To determine refractive change occurring with age in children who had cataract removal with intraocular lens implantation and in whom the immediate postoperative refraction was targeted either to match the refractive error of the opposite eye in unilateral cases, or for only a small refractive error when surgery was bilateral.

METHODS

Retrospective review of the refractive error over time in 36 eyes of 25 children who underwent cataract removal (11 bilateral) with insertion of an intraocular lens from 1987 to 1998 and who had at least 4 years follow-up, but no glaucoma.

RESULTS

Mean age at surgery was 5.5 years (median 5.7 y, range 1.3-12 y), with a mean follow-up of 8 years (median 6 y, range 4-16 y). The average refraction followed a logarithmic decline with age. Although eyes with unilateral surgery had a slightly faster rate of change and lower final refraction than did eyes with bilateral surgery, this difference was not statistically significant. Variation from this trend was also observed in 3 patients. When the hyperopic refractive error created immediately after surgery was small, children usually became significantly myopic when older, often creating anisometropic myopia in unilateral cases.

INTERPRETATION

When implanting intraocular lenses bilaterally one should aim for a significant but balanced hyperopic correction immediately postoperatively in young patients, anticipating that there will be emmetropization with aging. Parents should be warned that variations can occur.

Long term results of primary posterior chamber intraocular lens implantation for congenital cataract in the first year of life

AIM

To document the long term outcome of congenital cataract surgery with primary posterior chamber (PC) lens implantation in the first year of life.

METHOD

A retrospective review of congenital cataract surgery in the first year of life with PC lens implantation in 18 infants, eight with unilateral and 10 with bilateral cataract. The average age at surgery was 15 weeks (range 3-44 weeks). The mean follow up was 95 months (range 60-139 months).

RESULTS

The best outcomes were in the bilateral group where 50% of eyes achieved 6/18 or better, with a best acuity of 6/9. Acuities were poor in the unilateral group where only 38% achieved 6/60 or better, with a best acuity of 6/24. There was a mean refractive shift between first refraction after surgery and refraction at 36 months after surgery of -3.44 dioptres with a very wide range (+2.00 to -15.50). There was a significantly greater myopic shift in the unilateral cases. Many eyes in both groups continued to show an increasing myopic shift between 36 months after surgery and their final recorded refraction. The main complications were amblyopia, especially in unilateral cataracts, and posterior capsular opacification. Amblyopia was most probably related to a combination of early onset of dense cataract in this young age group, late presentation for initial surgery, delay in capsulotomies, and imperfect compliance with a rigorous occlusion regime.

CONCLUSION

Intraocular lens implantation in infants less than 1 year of age is generally a safe procedure. The spread of final refractive error was very wide. Final refraction in the unilateral group was significantly more myopic than the bilateral group. Final acuities were often disappointing especially in the unilateral group.

Visual acuity development after the implantation of unilateral intraocular lenses in infants and young children

PURPOSE

Intraocular lenses (IOLs) are now being implanted in infants and children with unilateral cataracts. However, there are no prospective data on the development of visual acuity after implantation. The aim of the present study was to prospectively assess the development of acuity in infants and preschool children who received IOLs or aphakic contacts lenses (CLs) after the extraction of a unilateral cataract.

METHODS

Visual acuity was assessed using Teller Acuity Cards and/or crowded HOTV tests at target ages of 6 months, 1, 2, 3, and 4 years.

RESULTS

Infants who received a primary IOL after extraction of dense congenital unilateral cataract (n = 5) showed improvement from an initially low mean visual acuity of 20/170 at 6 months to 20/85 at 12 months and 20/54 at 4 years. Visual acuity in the IOL group was similar to that of children who had good-to-excellent compliance with CL wear (n = 36; 4-year visual acuity 20/50) and better than that of children who had moderate-to-poor compliance (n = 11; 4-year visual acuity 20/135). Children who received IOLs after extraction of developmental unilateral cataracts by 6 months (n = 4; 4-year visual acuity 20/55) had visual acuity development similar to those treated with CLs (n = 5; 4-year visual acuity 20/55). Children who received IOLs after extraction of developmental unilateral cataracts after 1 year of age (n = 18) had better visual acuity than children those treated with CLs (n = 4) at 4 years of age (20/40 vs. 20/135).

CONCLUSION

IOLs and aphakic CLs support similar visual acuity development after surgery for a unilateral cataract. IOLs may support better visual acuity development when compliance with CL wear is moderate to poor or when a cataract is extracted after 1 year of age.

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.

Early postoperative refractive outcomes of pediatric intraocular lens implantation

PURPOSE

To evaluate the refractive outcome using 5 intraocular lens (IOL) calculation formulas to determine which best predicts refraction after pediatric cataract surgery.

SETTING

The Hospital for Sick Children, Toronto, Ontario, Canada.

METHODS

This study comprised a review of the charts of 158 consecutive patients aged 2 to 17 years old who were operated on by 1 of 2 staff surgeons between May 1992 and April 2000. The surgeons performed a total of 206 cataract extractions with primary or secondary IOL implantation. The measured outcome was the actual refraction 2 to 6 months postoperatively versus the target refraction. Two regression formulas (SRK, SRK II) and 3 theoretical formulas (Holladay 1, Hoffer Q, SRK/T) were used to predict refractive outcome based on preoperative axial length, corneal curvature, IOL power, and the IOL A-constant provided by the manufacturer.

RESULTS

Forty-nine patients (59 IOL implantations) with available data 2 to 6 months after surgery were studied. Also analyzed were data from a subset of 31 patients (34 IOL implantations) with available data 2 to 3 months after surgery. There was poor to moderate agreement between the predicted and actual postoperative refractions using the SRK formula (intraclass correlation coefficient [ICC] = 0.50/0.04 [2- to 3-month follow-up/2- to 6-month follow-up]) and good or fair agreement using the other formulas (ICC from 0.60/0.24 for SRK II to 0.67/0.37 for Hoffer Q). The mean difference between the predicted and actual postoperative refractions with all formulas ranged from 1.06 to 1.22 diopters (D)/1.35 to 1.79 D (median 0.81 to 0.99 D/0.94 to 1.40 D; range 3.03 to 5.57 D/6.75 to 9.21 D). Using Holladay 1 and SRK, 9% to 18%/23% to 39% eyes were more than +/-2.00 D off the target outcome refraction.

CONCLUSIONS

All 5 IOL power calculation formulas were unsatisfactory in achieving the target refraction. This finding may have implications for predicting long-term outcomes, interpreting previous reports of refractive outcomes, and obtaining preoperative informed consent in a clinical setting.

Long-term follow-up of eye growth in pediatric patients after unilateral cataract surgery with intraocular lens implantation

PURPOSE

To evaluate the refractive status, axial length, and refractive power of the cornea in pediatric patients after unilateral cataract surgery and intraocular lens implantation.

METHODS

Refractive state, refractive power of cornea, and axial length were measured both in the operated and nonoperated eyes in 15 patients (age at surgery = 5 to 15 years; mean, 10.3) before and 4 to 15 years (mean, 9.7) after unilateral cataract surgery.

RESULTS

After surgery, visual acuity was 20/40 or better in 79% of operated eyes. Myopic changes, representing the difference between postoperative refraction at last follow-up and postoperative refraction at 1 year after surgery, were noted in the operated eyes at the end of study (mean, -5.02 D), but there were no significant differences in axial length (Wilcoxon signed rank test P >.05) or refractive power of the cornea between operated and nonoperated eyes (paired Student t test P >.05).

CONCLUSION

Myopic shift after cataract surgery with intraocular lens implantation may occur even in older children.

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.

Epidemiology of refractive errors and presbyopia

Limitations in existing studies of the epidemiological aspects of refraction are attributed to both technical and statistical procedures. Early influences of ocular parameters on refraction are identified accordingly as prematurity and may or may not be involved. Attention is paid to familial and genetic influences, and infants and toddlers are examined as a group separate from schoolchildren and teenagers, who are likely to have experienced significant periods of near work. The effects of sex and geographical distribution are considered both for younger and older age ranges. Special attention is paid to anisometropia, which is shown-apparently for the first time-to increase appreciably among presbyopes. The connection between refractive errors and ocular pathologies is reviewed, and possible means of preventing early onset myopia are examined. Presbyopia is addressed with reference to its geographical distribution and hypothetical links to accommodation insufficiency.

Contact lenses for the treatment of pediatric cataracts

OBJECTIVE

To evaluate the experiences, attitudes, and perceptions of the caregivers of children with cataracts who were visually rehabilitated with contact lenses.

PARTICIPANTS

One hundred twenty-three caregivers of children <8.1 years old treated for unilateral and bilateral cataracts at one pediatric hospital.

DESIGN

Survey by questionnaire.

INTERVENTION

Primary caregivers were asked to complete an anonymous questionnaire.

MAIN OUTCOME MEASURES

Caregiver responses to questions assessing background and demographic and clinical information, as well as perceptions, attitudes, levels of compliance, and anxiety with respect to treatment, were reviewed. Caregivers were also asked to choose between aphakic rehabilitation with contact lenses, aphakic glasses, or intraocular lenses, given various hypothetical scenarios differing in regard to their final visual prognosis, risks of treatment complications, and cost.

RESULTS

The response rate was 82.9%. Absolute average stress levels for contact lens use were 1.36 +/- 1.79 and 0.79 +/- 1.48 (scale, 0-5) for insertion and removal, respectively, compared with 4.03 +/- 1.64 and 2.40 +/- 1.92 for cataract surgery and patching therapy, respectively. Although average paired initial resistance to treatment (RT) levels for contact lens insertion and removal on a scale of 0 to 3 were high (2.09 +/- 1.15) and moderate (1.63 +/- 1.20), respectively, final RT levels were significantly lower (1.09 +/- 1.14 and 0.66 +/- 1.07, respectively; P < 0.0001). The vast majority of caregivers chose contact lens use in hypothetical scenarios that depicted realistic expectations for other forms of aphakic rehabilitation.

CONCLUSIONS

In our study, contact lenses seemed to be well tolerated by most patients, as assessed by caregivers. Although initial resistance to contact lens use is high, this decreases with time. Relative to other events in the treatment of pediatric cataracts, contact lens use is not a major stressor for most caregivers and patients. This study supports the notion that contact lenses should continue to receive serious consideration as a treatment option for pediatric cataracts.

Minimal myopic shift in pseudophakic versus aphakic pediatric cataract patients

PURPOSE

To evaluate postoperative refractive changes in aphakic and pseudophakic children in a comparative case series.

METHODS

The medical records of pediatric patients with aphakia and pseudophakia were reviewed retrospectively. The mean change in refractive error from one postoperative examination to the next was calculated at each age to give aggregate curves of postoperative refractive change for each group.

RESULTS

A total of 233 aphakic and 92 pseudophakic eyes were studied. The median age at the time of surgery was 0.8 years (range, 0.0-16 years) for patients with aphakia and 7.3 years (range, 1.5-19.9 years) for patients with pseudophakia (P <.0001). The postoperative refraction curves at comparable ages of 2 to 20 years showed a total mean myopic shift of 1.5 D for patients with pseudophakia and 7.8 D for patients with aphakia. An age-matched subset of patients with aphakia also showed more myopic shift than those with pseudophakia.

CONCLUSIONS

Pseudophakic eyes show less postoperative myopic shift than aphakic eyes. Selecting intraocular lens powers aimed at producing initial emmetropic refractions has been a good strategy in our cohort of patients with pseudophakia. However, our data are insufficient for conclusions regarding children with pseudophakia younger than 2 years, in whom larger myopic shifts may occur.

Prospective analysis of pediatric pseudophakia: myopic shift and postoperative outcomes

PURPOSE

Limited data exist about long-term refractive changes in eyes of children with intraocular lens (IOL) implantation. Information of postoperative results should allow more accurate predictions for IOL power implantation in children. Data regarding IOL complications, including secondary membranes, myopic shift, stereopsis, and pseudophakic glaucoma should also be reported.

METHODS

In a prospective study, the refractive errors of all pediatric patients between 12 months and 18 years who had cataract surgery and IOL implantation were evaluated at 4 weeks, 3 months, 6 months, 1 year, and every 6 months thereafter. All patients were followed for a minimum of 3 years.

RESULTS

Fifty-two eyes of 42 patients met inclusion criteria. Forty-two eyes had developmental cataracts. There were 10 bilateral cases. Of the 52 eyes, 85% had 20/40 vision or better. Visual acuity of 20/30 or better was achieved in 95% of bilateral eyes. In unilateral cataracts, visual acuity was 20/50 or better in 74% of eyes. Mean follow-up time was 5.45 years with a range of 3 to 10.5 years. Mean follow-up by age group ranged between 4.38 and 6.35 years. Children operated on at 12 months to 2 years of age had a mean myopic shift of -5.96 D; children operated on at 3 and 4 years of age had a -3.66 D shift; children operated on at 5 and 6 years of age had a shift of -3.40 D; children operated on at 7 and 8 years of age had a shift of -2.03 D; children operated on at 9 and 10 years of age had a mean shift of -1.88 D; children operated on at 11 to 14 years of age had a shift of -0.97 D; children operated on at 15 to 18 years of age had -0.38 D shift. No cases of pediatric pseudophakic glaucoma were observed. Secondary membrane occurred in 72% of eyes when the capsule was left intact. The operated eye showed a greater mean myopic shift than the nonoperated eye. No statistically significant difference in refractive change was found comparing amblyopic to nonamblyopic eyes or traumatic to nontraumatic cataracts.

CONCLUSIONS

The greatest rate of refractive growth or change occurred between 1 and 3 years of age. After age 3 years, the rate of refractive growth followed a more linear trend. Based on this study, we have provided a guide for selecting IOL power in pediatric cataract cases using current formulas with the understanding that new formulas will need to be devised to better predict IOL power in children.

Refractive change in pediatric pseudophakia: 6-year follow-up

PURPOSE

To evaluate the long-term evolution of refractive error changes in eyes of children who have primary intraocular lens (IOL) implantation to allow more accurate prediction of what IOL power should be implanted at a given age.

SETTING

Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA.

METHODS

This study comprised all children between 2 and 15 years of age who had posterior chamber IOL implantation and who were followed for a minimum of 4 years postoperatively. Thirty-eight eyes of 27 patients with a mean follow-up of 6.1 years were evaluated. All refractions were performed manually by an experienced pediatric ophthalmologist.

RESULTS

Children operated on at age 2 or 3 years had a mean myopic shift of 4.60 diopters (D) (range 0.50 to 10.75 D) over a mean of 5.8 years postoperatively. Children operated on at age 6 or 7 years had a mean myopic shift of 2.68 D (range 0.50 to 6.60 D) over a mean of 5.3 years. Children operated on at age 8 or 9 years had a mean myopic shift of 1.25 D (range -0.75 to 2.60 D) over a mean of 6.8 years. Patients operated on between ages 10 and 15 years had a mean shift of 0.61 D (range 0 to 1.90 D) over a mean of 5.7 years.

CONCLUSIONS

The mean rate of myopic shift decreased throughout childhood, and the range of shift among individuals narrowed as patient age increased. However, the ability to predict future myopic shift for a given individual remains difficult, especially in younger patients.

Management of pediatric cataract and lens opacities

The diagnosis and surgical management of cataracts in children has benefitted from improvements in microsurgical techniques. Intraocular lens placement has become standard in children 2 years of age and older. Initial experience with intraocular lens implantation in infants found a high rate of surgical complications. However, refinements in surgical techniques may lesson these complications. Posterior capsule opacification is a frequent postoperative problem after pediatric cataract surgery. Posterior continuous curvilinear capsulorhexis with anterior vitrectomy is an effective means to prevent opacification of the visual axis in children.

Visual outcomes and complications of posterior chamber intraocular lens implantation in the first year of life

PURPOSE

To document the visual outcome and postoperative complications in infants who had congenital cataract surgery with posterior chamber intraocular lens (PC IOL) implantation in the first year of life.

SETTING

The Children's Hospital, Dublin, Ireland.

METHODS

Twenty-seven eyes of 20 infants were reviewed. Seven infants (14 eyes) had bilateral congenital cataract and 13 (13 eyes), uniocular cataract. The mean age at surgery was 4 months (range 3 weeks to 11 months). A standard surgical technique involved anterior capsulorhexis, phacoemulsification with or without posterior capsulorhexis with in-the-bag PC IOL implantation, and no anterior vitrectomy. Surgery was performed by 1 surgeon. The mean follow-up was 41 months (range 6 to 88 months).

RESULTS

The main complication was lens reproliferation into the visual axis. Of the 11 eyes that did not have a primary posterior capsulorhexis, 10 had 1 or more capsulotomies. Seven required a neodymium:YAG (Nd:YAG) laser capsulotomy a mean of 6 months postoperatively, and 2 had 2 Nd:YAG capsulotomies. Six eyes also had a surgical capsulotomy when the membrane was deemed too thick for further laser treatment. Fourteen of 25 eyes had a primary posterior capsulorhexis; 8 had no further intervention. Four eyes had persistent hyperplastic primary vitreous (PHPV), 3 required a surgical capsulotomy, 2 had an Nd:YAG laser capsulotomy, 2 had an anterior vitrectomy, and 1 developed open-angle glaucoma. There was a mean refractive shift of 6.0 diopters after a mean follow-up of 41 months, with most of the myopic shift occurring in the first 24 months.

CONCLUSIONS

Visual axis reopacification was the main complication of IOL implantation in infants, with PHPV leading to more complications and repeat procedures. Anterior vitrectomy appeared to reduce the reoperation rate. Results indicate that primary posterior capsulorhexis is important and Nd:YAG capsulotomy is not satisfactory in infants. In addition, the reduction in glaucoma with IOL implantation, if borne out over the long term, is a significant advantage in cases of congenital cataract.

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.