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Intraocular lens implantation during infancy: perceptions of parents and the American Association for Pediatric Ophthalmology and Strabismus members
Intraocular Lens Implantation During Infancy: Perceptions of Parents and the American Association for Pediatric Ophthalmology and Strabismus Members Scott R. Lambert, MD,a Michael Lynn, PhD,b Carolyn Drews-Botsch, PhD,a,c Lindreth DuBois, MEd, MMSc, CO,a M. Edward Wilson, MD,d David A. Plager, MD,e David T. Wheeler, MD,f Stephen P. Christiansen, MD,g Earl R. Crouch, MD,h Edward G. Buckley, MD,i David Stager, Jr, MD,j and Sean P. Donahue, MD, PhDk 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. (J AAPOS 2003;7:400-5)
From Emory Eye Center,aand the Departments of Biostatisticsb and Epidemiology,c Rollins School of Public Health, Emory University, Atlanta, GA; Medical University of South Carolina,d Charleston, SC; Indiana University Medical Center,e Indianapolis, IN; OHSU Casey Eye Institute,f Portland, OR; University of Minnesota,g Minneapolis, MN; East Virginia Medical School,h Norfolk, VA; Duke Eye Center,i Durham, NC; University of Texas Southwestern Medical Center,j Dallas, TX; and Vanderbilt Eye Center,k Nashville, TN USA. Supported in part by the Emory Egleston Children’s Research Center, Atlanta, GA; the Knights Templar Eye Foundation, Chicago, IL; Research to Prevent Blindness, Inc, New York, NY; and National Institutes of Health Core Grant No. P30 EY06360, Bethesda, MD. Submitted April 1, 2003. Revision accepted August 5, 2003. Reprint requests: Scott R. Lambert, MD, Emory Eye Center, 1365-B Clifton Rd NE, Atlanta, GA 30322. Copyright © 2003 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2003/$35.00 ⫹ 0 doi:10.1016/j.jaapos.2003.08.004
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ntraocular lens (IOL) implantation after cataract surgery in children ⱖ2 years old is widely accepted ,1-2 but the implantation of IOLs during infancy is still controversial.3 Results of small, noncontrolled studies3 have shown an increased incidence of pupillary membranes requiring reoperation in infants undergoing cataract surgery combined with primary IOL implantation.4-6 These membranes typically consist of reproliferating lens material that extends across the pupillary space. Despite the apparent increased incidence of reoperation in infant eyes after primary IOL implantation, pseudophakic eyes have been reported to have better visual results than agematched aphakic eyes corrected with contact lenses (CLs).4,7 We are organizing a randomized multicenter
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clinical trial (Infant Aphakia Treatment Study) to compare the visual outcome of children with unilateral aphakia corrected with a CL versus IOL implant. To determine the feasibility of such a clinical trial, we surveyed the membership of the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) in both 1997 and 2001 and also conducted a pilot study to ascertain the willingness of parents to randomize their children to these two treatments. We report here the results of the surveys and the pilot study.
METHODS AAPOS Surveys In August 1997 and June 2001, we mailed a one-page survey to all members of AAPOS in the United States and Canada (n ⫽ 650) to ascertain their perceptions regarding the use of IOL implants and CLs to correct aphakia in infants and their willingness to participate in a randomized clinical trial comparing these two treatments. Randomization Pilot Study In March 2002, we initiated a pilot study to determine the willingness of parents to randomize their child with a unilateral congenital cataract (UCC) to treatment with a CL or an IOL implant after cataract surgery. Approval for the study was obtained from the Institutional Review Boards of all participating institutions. In addition, an investigational device exemption (no. G020021/S1) was obtained from the Food and Drug Administration to enroll up to 30 patients at 13 institutions. To be eligible for the study, patients had to be ⬍7 months old and have a visually significant UCC. In addition, patients were excluded if they were delivered at gestational age ⬍36 weeks, had undergone any previous intraocular surgery, had a syndrome associated with mental retardation, or had an abnormality in the fellow eye. After identifying children with visually significant UCCs, investigators explained the study to the parents of these children and gave them an informed consent form and a patient brochure, approved by the Institutional Review Board, to review. After being given the opportunity to review these materials and to ask questions regarding the procedures, parents signed the informed consent if they were willing to let their child be randomized to either treatment. Examination under anesthesia/cataract surgery was scheduled when the child was ⱖ28 days old. Screening, office examination, and patient contact forms were then completed and faxed to the Data Coordinating Center (DCC). At the time of examination under anesthesia, tonometry, biomicroscopy, keratometry, retinoscopy, indirect ophthalmoscopy, and biometry were performed. Children were then enrolled in the study if the following criteria were met: cataract was confirmed to be visually significant and ⱖ3 mm; corneal diameter was ⱖ9 mm; intraocular pressure was ⬍22 mm Hg; ciliary processes were normal; eye was free of uveitis; retina was normal; and fellow eye was normal. A sealed treatment
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assignment envelope was then opened by the surgeon, and the child underwent cataract surgery either with or without IOL implantation depending on the treatment group assignment. For the children assigned to the contact lens group, two stab incisions were made superiorly at the limbus. An infusion cannula was placed through one incision and a vitreous-cutting instrument through the other. The vitreous-cutting instrument was used to create a mechanized anterior capsulotomy ⱖ5 mm. The lens nucleus and cortex was aspirated with the vitreous-cutting instrument. A posterior capsulotomy ⱖ4 mm was created with the vitreouscutting instrument. Finally, an anterior vitrectomy was performed through the posterior capsulotomy. The stab incisions were closed with either 9-0 or 10-0 Vicryl (Ethicon, Somerville, NJ) suture material, and cefazolin (American Pharmaceutical, Los Angeles, CA) and dexamethasone were injected subconjunctivally. One drop of 1% atropine and an antibiotic/steroid ointment was placed in the eye, the eye was patched, and a shield was placed over the eye. For the children assigned to the intraocular lens group, a 3.0-mm scleral tunnel incision was created superiorly and a stab incision was made laterally at the limbus. An infusion cannula was placed through the stab incision. Next, a stab incision was made through the scleral tunnel. An anterior capsulotomy ⱖ5 mm was created either manually with a capsulorhexis forceps or mechanically with a vitreous-cutting instrument. The lens nucleus and cortex was aspirated with the vitreous-cutting instrument. The capsular bag was filled with Healon (Pharmacia and Upjohn, Kalamazoo, MI), and an AcrySof SA-60 IOL (Alcon Surgical, Fort Worth, TX) was implanted into the capsular bag. The power of the IOL implant was calculated using the Holladay 1 formula with a targeted postoperative refraction of ⫹6.00 prism diopters (PD). The scleral tunnel incision was closed with interrupted 9-0 or 10-0 Vicryl suture material, and the Healon was removed with an irrigation-aspiration instrument. A stab incision was made 1.5 to 2.0 mm posterior to the limbus. A central posterior capsulotomy ⱖ4 mm was created with the vitreous-cutting instrument while the anterior chamber was infused through the lateral stab incision. The posterior stab incision was closed with 7-0 Vicryl suture material, and the anterior stab incision was closed with 9-0 or 10-0 Vicryl suture material. Cefazolin and dexamethasone were injected subconjunctivally. One drop of 1% atropine and an antibiotic/steroid ointment were placed in the eye, and the eye was patched and covered with a shield. An examination under anesthesia/surgery form was then faxed to the DCC. The parents of the children in both treatment groups were asked to patch the unoperated eye 1 hour per day for 1 month after surgery whenever the child was awake. After the child was 8 months of age, parents were asked to patch the unoperated eye every other day during the entire time the child was awake.
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TABLE 1. Number of unilateral congenital cataracts treated in the past year by responding pediatric ophthalmologists
Response Interested in participating in randomized clinical trial Not interested in participating in randomized clinical trial Total
TABLE 2. Age of the youngest child in whom respondents had implanted an IOL Age (mo)
None
1 to 5
6 to 10
11 to 20
20
Total
8
106
14
4
1
133
20
94
4
1
0
119
⬍7 7 to 12 13 to 24 25 to 36 ⬎36 Total
Number
%
8 12 62 66 78 228
4 6 27 29 34 100.0
IOL: intraocular lens.
28
200
18
5
1
252
The patients were examined at 1 day, 1 week, 1 month, and 3 months after surgery. The patients were monitored for ocular complications at each of these examinations. If a complication was identified, a form was completed and faxed to the DCC. If reoperation was necessary, reoperation and complication narrative forms were completed and faxed to the DCC. The patients will continue to be followed up for at least 3 years.
RESULTS AAPOS Surveys A total of 260 (40%) of the 1997 and 269 (41%) of the 2001 surveys were returned. In the 1997 survey, most of the respondents (89%) reported treating at least 1 infant with a UCC during the previous year (Table 1). Six (3%) reported treating ⱖ11 infants with a UCC and 24 (10%) reported treating 6 to 11 infants with a UCC during the past year. In all, the respondents indicated that they treated at least 383 infants with a UCC during the previous year. More than one half (53%) of the respondents indicated that they would be interested in participating in a study comparing the use of a CL with IOL implant to optically correct an infant ⬍6 months of age after UCC cataract surgery. Of the 228 respondents from the 1997 survey who provided the age of the youngest child in whom they had implanted an IOL, 84 (37%) had implanted an IOL in a child ⱕ2 years old; 22 (10%) in an infant ⱕ12 months old; and 8 (4%) in an infant ⱕ6 months old (Table 2). For aphakic eyes, the majority of respondents used Silsoft (Bausch and Lomb, Rochester, NY) CLs exclusively (n ⫽ 208, 84%). Another 21 (9%) only used rigid gas-permeable CLs; the remaining respondents used both Silsoft and rigid gas permeable RGP CLs (n ⫽ 12, 5%) or another type of CL (n ⫽ 7, 3%). In the 1997 survey, age of the child (n ⫽ 52), ease of use (n ⫽ 49), increased compliance (n ⫽ 43), and ease of fit (n ⫽ 32) were the most important reasons cited for choosing a particular type of CL (Table 3). In the 2001 survey, on a scale from 1 to 10 with 1 strongly favoring IOL implant and 10 strongly favoring
TABLE 3. Most important reasons for selecting a particular type of contact lens to prescribe in UCC cases cited by responding pediatric ophthalmologists
Reason Age of child (mo) Cost of lens ($) Likelihood of loss Increased compliance Ease of fit Ease of obtaining Ease of use Improved compliance
Second Most Most Important Important
Third Most Important
Median
n
%
%
n
%
0 0 0 1 1 0 2 0
52 0 5 43 32 10 49 27
24.4 0.0 2.5 20.4 15.7 4.9 24.0 13.1
15 7.0 7 3.4 13 6.4 57 27.0 41 20.2 10 4.9 57 27.9 14 6.8
11 17 23 34 33 16 52 26
5.2 8.3 11.3 16.1 16.3 7.8 25.5 12.6
n
UCC: unilateral congenital cateract.
CL, the median score was 7.5 (median absolute deviation ⫽ 2.0) (Figure 1). Forty-one (15%) respondents chose “10” indicating a strong preference for CLs, and 11 (4%) chose “1” indicating a strong preference for IOL implants, although the remaining 208 respondents chose an intermediate preference. Fifty-eight (21%) of the respondents had implanted an IOL in an infant during the previous year. One hundred-seventy respondents (61%) indicated that they would be willing to randomize an infant (1 to 6 months old) with a UCC to treatment with an IOL implant or a CL in a National Institutes of Health–funded multicenter clinical trial. The most commonly cited concerns about CL correction were poor compliance (n ⫽ 52), high lens loss rate (n ⫽ 24), high cost (n ⫽ 21), and keratitis (n ⫽ 12). The most commonly cited concerns about IOL implant correction were poor predictability of refractive changes (n ⫽ 52), postoperative complications (n ⫽ 46), inflammation (n ⫽ 19), and technical difficulty of surgery (n ⫽ 14). Randomization Pilot Study From March 2002 to February 21, 2003, we conducted a prospective pilot study to ascertain the willingness of parents to randomize their child to treatment with a CL or IOL implant after cataract surgery and to validate our protocol. A total of 30 children were screened at nine clinical centers. Six were ineligible for the following rea-
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TABLE 4. Reasons for refusing randomization Preferred contact lens treatment Preferred IOL treatment Parental disagreement on treatment IATS surgeon out-of-network for HMO Transportation problems
3 1 1 1 1
HMO: health maintenance organization; IATS: Infant Aphakia Treatment Study; IOL: intraocular lens.
TABLE 5. Clinical findings in children randomized to treatment Clinical Finding Corneal diameter (mm) Axial length (mm) Keratometry reading (PD) FIG 1. Preferences of AAPOS members for the optical treatment of infants six months of age or younger with a visually significant unilateral cataract.
sons: prematurity (n ⫽ 2), ⱖ7 months old at the time of cataract surgery (n ⫽ 2), small cataract in the fellow eye (n ⫽ 1), and mental retardation (n ⫽ 1). Of the 24 eligible patients, the parents of 17 (71%) agreed to have their child undergo randomization. The parents of 6 eligible patients refused randomization for the reasons listed in Table 4. At the time of surgery, the mean age of the enrolled patients was 2.8 ⫾ 2.1 months. Eight patients underwent cataract surgery when they were ⬍ 7 weeks old. Eight of the patients were referred by pediatricians, 5 by pediatric ophthalmologists, and 4 by comprehensive ophthalmologists. Eleven of the patients were white, and five were black; nine were female, and eight were male. Ten of the cataracts were nuclear, two had persistent fetal vasculature, and two had posterior lentiglobus. Nine children were randomized to IOL implant correction and eight to CL correction. The cataractous eyes were slightly microphthalmic compared with their fellow eyes and had smaller corneal diameters, shorter axial lengths, and steeper corneas (Table 5). The IOL was implanted in the capsular bag in eight of the nine pseudophakic eyes. The only intraoperative complication reported was iris prolapse with a small superior iridodialysis in one patient in the IOL implant group. The only complication reported at the 1-day postoperative examination was a hyphema in one patient in the IOL implant group, which resolved by the 1-week examination. At the 1-week examination, two patients in the IOL implant group had developed pupillary membranes. A third patient in the IOL implant group was noted to have a pupillary membrane at the 3-month examination and a fourth at the 4-month examination. All four patients underwent reoperation to open the pupillary membrane. One of the patients in the IOL implant group who was noted to have a pupillary membrane at the 1-week examination subsequently developed glaucoma in the pseudophakic eye and underwent a trabeculectomy at 2 months of age. This eye was noted before surgery to be
Treated Eye (Mean ⴞ SD)
Fellow Eye (Mean ⴞ SD)
10.3 ⫾ 0.9 18.1 ⫾ 1.5 46.5 ⫾ 3.3
10.7 ⫾ 0.7 18.7 ⫾ 1.0 45.9 ⫾ 2.4
microophthalmic (corneal diameter ⫽ 9 mm) and to have persistent fetal vasculature. None of the patients in the CL group have developed a pupillary membrane, but one eye did develop glaucoma in the aphakic eye 2 months after a lensectomy and anterior vitrectomy. Before surgery, this infant was noted to have 360° of posterior embryotoxin in both eyes. In retrospect, this child should have been excluded from participating in the study because the fellow eye was not normal.
DISCUSSION The perception of pediatric ophthalmologists regarding the implantation of IOLs in children has changed radically during the past two decades. Early reports of IOL implantation during childhood emphasized the high complication rate associated with their use.8-13 As a result, some investigators recommended that IOLs be implanted only in older children with unilateral traumatic cataracts or in children who could not tolerate CLs.8-9,14 Results of many of these early case series also showed that anterior chamber and iris fixation CLs were associated with fewer complications than were posterior chamber IOL implants.9-10 In 1990, Dahan and Salmenson15 reported good visual results and relatively few complications in 80 children who underwent posterior chamber IOL implantation after cataract surgery. The investigators emphasized the importance of performing an elective posterior capsulotomy and anterior vitrectomy because of the high incidence of posterior capsular opacification in these eyes. Since then, posterior chamber IOL implants have become the implant of choice for children. By 1994, 46% of the responding AAPOS members had implanted an IOL in a child ⱕ2 years old.16 In 1996, Wilson17 suggested that posterior chamber IOL implantation had become the standard of care for children ⱖ2 years old. Results of our 2001 survey suggested that the responding AAPOS members still preferred to use CLs for optically correcting infants after unilateral cataract surgery. However, the percentage of the responding AAPOS members who had implanted an IOL
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in an infant after cataract surgery increased from 4% in 1997 to 21% in 2001, a five-fold increase. The most commonly cited concern about IOL implantation in our 2001 survey was the poor predictability of the refractive changes these eyes experience. The human eye undergoes rapid axial elongation during the first 2 years of life.18 In addition, the cornea flattens during the first 6 months.19 Although removing the crystalline lens and implanting an IOL may retard the axial elongation of an infant eye,20-21 the rapid growth of an infantile eye still results in a large myopic shift. Dahan7 reported a myopic shift of 6.93 ⫾ 3.42 D after a 7.7 year follow-up of 34 children (68 eyes) who had undergone IOL implantation during the first 18 months of life. The mean increase in axial length in these eyes was 3.59 ⫾ 1.80 mm. Wilson5 reported a myopic shift of 6.22 D after a 21 month follow-up of 16 children (32 eyes) who underwent IOL implantation during the first year of life. After a mean follow-up of 13 months, Lambert22 reported a mean myopic shift of 5.29 D in the pseudophakic eye of 11 children who underwent IOL implantation during the first 6 months of life. Others have noted large myopic shifts even in children 1 to 3 years old. Crouch23 recently reported a mean myopic shift of 5.96 D after a 6.35 year follow-up of children who underwent IOL implantation at 1 to 2 years of age. Plager24 noted a mean myopic shift of 4.60 D (range, 0.50 to 10.75) after a mean postoperative follow-up of 5.8 years in children who underwent cataract surgery at 2 to 3 years of age. In our study, our targeted undercorrection was 6 D in the children randomized to the IOL implant group. Longer-term follow-up in prospective studies, such as the proposed Infant Aphakia Treatment study, should help to establish the optimal nomogram for choosing the IOL implant power after infant cataract surgery. Another significant concern of AAPOS members in our 2001 survey was the high rate of reoperation after infant IOL implantation. Several investigators have noted a high rate of reoperation in infant eyes after IOL implantation, even after a primary posterior capsulotomy and anterior vitrectomy. Lambert22 reported that 8 of 11 eyes (83%) undergoing IOL implantation during the first 6 months of life required a reoperation. In 4 eyes (38%) a pupillary membrane or cortex reproliferation had to be excised from the visual axis. In 2 other eyes the iris had to be swept from the surgical incision site. In addition, 2 eyes developed glaucoma and underwent glaucoma surgery. Plager6 reported that 12 of 15 eyes (80%) developed pupillary membranes obstructing the visual axis after IOL implantation during the first 6 months of life. In addition, 2 of these eyes had to undergo a second operation to clear the visual axis, and 1 eye developed glaucoma. After follow-up of 12 months or longer, Wilson5 reported a 21% incidence of pupillary membranes requiring reoperation in a cohort of children undergoing IOL implantation. In addition, 3 eyes (9%) developed glaucoma, and 1 eye had to undergo reoperation to sweep the iris from the surgical incision site.
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Poor compliance was the most commonly identified problem with CL correction. Assaf et al25 reported that only 44% of children in Saudi Arabia with unilateral aphakia were wearing their CL when they returned for followup. Poor compliance in children with unilateral aphakia is multifactorial, but contributing factors include the high cost of CLs, the inability of children to discern a visual benefit from CL use if the fellow eye has normal vision, and the difficulty of caregivers inserting and removing CLs in a small child. The loss of CLs was cited as another important problem with CL wear. Amos et al26 reported a lost lens rate of 2.4 CLs/eye/y in a small series of aphakic children wearing rigid gas-permeable CLs. Holmstrom et al27 reported dispensing, on average, 22.8 soft CLs/eye/y for aphakic children. They attributed the high turnover rate of CLs during the first 6 months of treatment to the frequent parameter changes and the initial difficulties that parents have handling CLs. CL wear may be prohibitively expensive for some families, particularly in developing countries.28 In the United States, many health insurance plans do not cover the cost of CLs even when they are worn to correct aphakia. The incidence of keratitis in children wearing CLs for aphakia is not known. Although anecdotal reports would suggest that keratitis occurs more often in the setting of Silsoft CLs worn on an extended basis, a recent report by Cavanaugh et al29 suggested that CLs with a high gas transmissibility (DK) may be associated with a lower risk of bacterial keratitis. Because Silsoft CLs have the highest DK of any commercially available CL, this may account for the relatively low incidence of bacterial keratitis in aphakic children wearing Silsoft CLs. The percentage of AAPOS members who indicated that they would be willing to participate in a study comparing CL correction with IOL implantation in infants increased from 53% in our 1997 survey to 61% in our 2001 survey. Nonetheless, the majority of AAPOS members still favored a CL correction for an infant ⬍7 months of age with a UCC. When asked to indicate their preference on a scale of 1 to 10 with 1 strongly favoring an IOL implant and 10 strongly favoring a CL, the median score was 7.5. However, the fact that 61% of AAPOS members were willing to enroll an infant with a UCC into a randomized clinical trial comparing these two treatments suggest that nearly two thirds were undecided as to which treatment is best. Parents had equipoise regarding the use of IOL implants and CLs once the relative advantages and disadvantages of each were explained to them. In our pilot study, the parents of 17 of 24 (71%) eligible patients agreed to be randomized to either treatment after cataract surgery. In the Cryotherapy for Retinopathy of Prematurity (CRYOROP) study, the parents of 4,901 of 5,822 (84%) eligible patients consented to randomization.30 In our study, parents were slightly less willing to be randomized in our study than in the CRYO-ROP study. The lower rate of randomization in our study may reflect the fact that the
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children in our study were all outpatients, and their parents may have had more time to consider the two treatment options. In some cases, parents declined randomization after extensively researching the two treatment options on the Internet or consulting with other pediatric ophthalmologists; this would not have been possible for the parents of the children in the CRYO-ROP study. Parents often chose one treatment based on the compatibility of the treatment with their lifestyle. Although the innovative aspect of IOL implantation was appealing to certain parents initially, once they understood the risks and benefits of both treatment options, innovation was not a significant factor in the decision making process for most parents.31 The complication rate in our pilot study was similar to what has been reported previously. Pupillary membranes or cortex reproliferation occurred within 6 months or less in four of the nine (45%) children randomized to IOL implantation. In three of four cases, reoperation was necessary during the first 3 postoperative months. One child in the aphakic group and one in the pseudophakic group developed glaucoma. Although it has been suggested that IOL implantation may decrease the risk of glaucoma in aphakic eyes, this likely reflects a selection bias in the children who have undergone IOL implantation in the past.32,33 Both of the patients in our study who developed glaucoma had a risk factor for glaucoma (ie, one child had persistent fetal vasculature and microphthalmos and the other had 360° of posterior embryotoxin). As children increasingly undergo IOL implantation during infancy, it is becoming clear that glaucoma will develop in some of these eyes.5,22 The results of our pilot study suggested that both pediatric ophthalmologists and parents have equipoise regarding the use of an IOL implant versus a CL to optically correct an infant ⬍7 months old with a UCC after cataract surgery. We hope to conduct a large multicenter clinical trial to more carefully ascertain the risks and benefits of these two treatments. References 1. Taylor D. Congenital cataract: the history, the nature and the practice. Eye 1998;12:9-36. 2. Wright KW. Lens abnormalities. In: Wright KW, Spiegel PH, editors. Pediatric ophthalmology and strabismus. New York (NY): Springer-Verlag; 2003. p. 469. 3. Ma JJK, Morad Y, Mau E, Brent HP, Barclay R, Levin AV. Contact CLs for the treatment of pediatric cataracts. Ophthalmology 2003; 110:299-305. 4. Lambert SR, Lynn M, Drews-Botsch C, Fawcett S, Loupe D, Plager DA, et al. A comparison of grating visual acuity, strabismus, and reoperation outcomes among children with aphakia and pseudophakia after unilateral cataract surgery during the first six months of life. J AAPOS 2001;5:70-5. 5. Wilson ME, Peterseim MW, Englert JA, Lall-Trail JK, Elliott LA. Pseudophakia and polypseudophakia in the first year of life. J AAPOS 2001;5:238-45. 6. Plager DA, Yang S, Neely D, Sprunger D, Sondhi N. Complications in the first year after cataract surgery with and without IOL in infants and older children. J APPOS 2002;6:9-14.
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7. Dahan E, Drusedau MUH. Choice of lens and dioptric power in pediatric pseudophakia. J Cataract Refract Surg 1997;23:618-23. 8. Hiles DA. Intraocular lens implantation in children with monocular cataracts. Ophthalmology 1984;91:1231-7. 9. Hiles DA, Hered RW. Modern intraocular lens implants in children with new age limitations. J Cataract Refract Surg 1987;13:493-7. 10. Burke JP, Willshaw HE, Young JDH. Intraocular lens implants for uniocular cataracts in childhood. Br J Ophthalmol 1989;73:860-4. 11. Wilson-Holt N, Hing S, Taylor DSI. Bilateral blinding uveitis in a child after secondary intraocular lens implantation for unilateral congenital cataract. J Pediatr Ophthalmol Strabismus 1991;28:116-8. 12. Taylor D. Monocular infantile cataract, intraocular CLs, amblyopia [editorial]. Br J Ophthalmol 1989;73:857-8. 13. Hiles DA. Intraocular CLs. Surv Ophthalmol 1990;34:371-9. 14. Rosenbaum AL. Consultation section. J Cataract Refract Surg 1991; 17:515. 15. Dahan E, Salmenson BD. Pseudophakia in children: precautions, technique, and feasibility. J Cataract Refract Surg 1990;16:73-82. 16. Wilson ME, Bluestein EC, Wang X-H. Current trends in the use of intraocular CLs in children. J Cataract Refract Surg 1994;20:579-83. 17. Wilson ME. Intraocular lens implantation: has it become the standard of care for children? Ophthalmology 1996;103:1719-20. 18. Gordon RA, Donzis PB. Refractive development of the human eye. Arch Ophthalmol 1985;103:785-9. 19. Inagaki Y. The rapid change of corneal curvature in the neonatal period and infancy. Arch Ophthalmol 1986;104:1026-7. 20. Griener ED, Dahan E, Lambert SR. Effect of age at time of cataract surgery on subsequent axial length growth in infants eyes. J Cataract Refract Surg 1999;25:1209-13. 21. McClatchey SK, Dahan E, Maselli E, et al. A comparison of the rate of refractive growth in pediatric aphakic and pseudophakic eyes. Ophthalmology 2000;107:118-22. 22. Lambert SR, Buckley EG, Plager DA, Medow NB, Wilson ME. Unilateral intraocular lens implantation during the first six months of life. J AAPOS 1999;3:334-9. 23. Crouch ER, Crouch ER Jr, Pressman SH. Prospective analysis of pediatric pseudophakia: myopic shift and postoperative outcomes. J AAPOS 2002;6:277-82. 24. Plager DA, Kipfer H, Sprunger DT, Sondhi N, Neely DE. Refractive change in pediatric pseudophakia: 6-year follow-up. J Cataract Refract Surg 2002;28:810-5. 25. Assaf AA, Wiggins R, Engel K, Senft S. Compliance with prescribed optical correction in cases of monocular aphakia in children. Saudi J Ophthalmol 1994;8:15-22. 26. Amos CF, Lambert SR, Ward MA. Rigid gas permeable contact lens correction of aphakia after congenital cataract removal during infancy. J Pediatr Ophthalmol Strabismus 1992;29:243-5. 27. Holmstro¨m G, Speedwell L, Taylor D. Contact CLs—still the only solution for infant aphakia. Euro J Implant Refract Surg 1990;2: 265-7. 28. Wilson ME, Pandy SK, Thakur J. Paediatric cataract blindness in the developing world: surgical techniques and intraocular CLs in the new millennium. Br J Ophthalmol 2003;87:14-9. 29. Cavanagh HD, Ladage PM, Li SL, Yamamoto K, Molar M, Ren DH, et al. Effects of daily and overnight wear of a novel hyper oxygentransmissible soft contact lens on bacterial binding and corneal epithelium: a 13 month clinical trial. Ophthalmology 2002;109:1957-69. 30. Cryotherapy for Retinopathy of Prematurity Cooperative Group. Multicenter trial of cryotherapy for retinopathy of prematurity. Three-month outcome. Arch Ophthalmol 1990;108:195-204. 31. Levin V. IOLs, innovation and ethics in pediatric ophthalmology: let’s be honest. J AAPOS 6:133-6. 32. Donahue SP, Byrne D, Wilson ME, Sinha D. Aphakic glaucoma in children. J AAPOS 2000;4:389-90. 33. Asrani A, Freedman S, Hasselblad V, Buckley EG, Egbert J, Dahan L, et al. Does primary intraocular lens implantation prevent “aphakic” glaucoma in children? J AAPOS 1999;3:33-9.
From Emory Eye Center,aand the Departments of Biostatisticsb and Epidemiology,c Rollins School of Public Health, Emory University, Atlanta, GA; Medical University of South Carolina,d Charleston, SC; Indiana University Medical Center,e Indianapolis, IN; OHSU Casey Eye Institute,f Portland, OR; University of Minnesota,g Minneapolis, MN; East Virginia Medical School,h Norfolk, VA; Duke Eye Center,i Durham, NC; University of Texas Southwestern Medical Center,j Dallas, TX; and Vanderbilt Eye Center,k Nashville, TN USA. Supported in part by the Emory Egleston Children’s Research Center, Atlanta, GA; the Knights Templar Eye Foundation, Chicago, IL; Research to Prevent Blindness, Inc, New York, NY; and National Institutes of Health Core Grant No. P30 EY06360, Bethesda, MD. Submitted April 1, 2003. Revision accepted August 5, 2003. Reprint requests: Scott R. Lambert, MD, Emory Eye Center, 1365-B Clifton Rd NE, Atlanta, GA 30322. Copyright © 2003 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2003/$35.00 ⫹ 0 doi:10.1016/j.jaapos.2003.08.004
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ntraocular lens (IOL) implantation after cataract surgery in children ⱖ2 years old is widely accepted ,1-2 but the implantation of IOLs during infancy is still controversial.3 Results of small, noncontrolled studies3 have shown an increased incidence of pupillary membranes requiring reoperation in infants undergoing cataract surgery combined with primary IOL implantation.4-6 These membranes typically consist of reproliferating lens material that extends across the pupillary space. Despite the apparent increased incidence of reoperation in infant eyes after primary IOL implantation, pseudophakic eyes have been reported to have better visual results than agematched aphakic eyes corrected with contact lenses (CLs).4,7 We are organizing a randomized multicenter
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clinical trial (Infant Aphakia Treatment Study) to compare the visual outcome of children with unilateral aphakia corrected with a CL versus IOL implant. To determine the feasibility of such a clinical trial, we surveyed the membership of the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) in both 1997 and 2001 and also conducted a pilot study to ascertain the willingness of parents to randomize their children to these two treatments. We report here the results of the surveys and the pilot study.
METHODS AAPOS Surveys In August 1997 and June 2001, we mailed a one-page survey to all members of AAPOS in the United States and Canada (n ⫽ 650) to ascertain their perceptions regarding the use of IOL implants and CLs to correct aphakia in infants and their willingness to participate in a randomized clinical trial comparing these two treatments. Randomization Pilot Study In March 2002, we initiated a pilot study to determine the willingness of parents to randomize their child with a unilateral congenital cataract (UCC) to treatment with a CL or an IOL implant after cataract surgery. Approval for the study was obtained from the Institutional Review Boards of all participating institutions. In addition, an investigational device exemption (no. G020021/S1) was obtained from the Food and Drug Administration to enroll up to 30 patients at 13 institutions. To be eligible for the study, patients had to be ⬍7 months old and have a visually significant UCC. In addition, patients were excluded if they were delivered at gestational age ⬍36 weeks, had undergone any previous intraocular surgery, had a syndrome associated with mental retardation, or had an abnormality in the fellow eye. After identifying children with visually significant UCCs, investigators explained the study to the parents of these children and gave them an informed consent form and a patient brochure, approved by the Institutional Review Board, to review. After being given the opportunity to review these materials and to ask questions regarding the procedures, parents signed the informed consent if they were willing to let their child be randomized to either treatment. Examination under anesthesia/cataract surgery was scheduled when the child was ⱖ28 days old. Screening, office examination, and patient contact forms were then completed and faxed to the Data Coordinating Center (DCC). At the time of examination under anesthesia, tonometry, biomicroscopy, keratometry, retinoscopy, indirect ophthalmoscopy, and biometry were performed. Children were then enrolled in the study if the following criteria were met: cataract was confirmed to be visually significant and ⱖ3 mm; corneal diameter was ⱖ9 mm; intraocular pressure was ⬍22 mm Hg; ciliary processes were normal; eye was free of uveitis; retina was normal; and fellow eye was normal. A sealed treatment
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assignment envelope was then opened by the surgeon, and the child underwent cataract surgery either with or without IOL implantation depending on the treatment group assignment. For the children assigned to the contact lens group, two stab incisions were made superiorly at the limbus. An infusion cannula was placed through one incision and a vitreous-cutting instrument through the other. The vitreous-cutting instrument was used to create a mechanized anterior capsulotomy ⱖ5 mm. The lens nucleus and cortex was aspirated with the vitreous-cutting instrument. A posterior capsulotomy ⱖ4 mm was created with the vitreouscutting instrument. Finally, an anterior vitrectomy was performed through the posterior capsulotomy. The stab incisions were closed with either 9-0 or 10-0 Vicryl (Ethicon, Somerville, NJ) suture material, and cefazolin (American Pharmaceutical, Los Angeles, CA) and dexamethasone were injected subconjunctivally. One drop of 1% atropine and an antibiotic/steroid ointment was placed in the eye, the eye was patched, and a shield was placed over the eye. For the children assigned to the intraocular lens group, a 3.0-mm scleral tunnel incision was created superiorly and a stab incision was made laterally at the limbus. An infusion cannula was placed through the stab incision. Next, a stab incision was made through the scleral tunnel. An anterior capsulotomy ⱖ5 mm was created either manually with a capsulorhexis forceps or mechanically with a vitreous-cutting instrument. The lens nucleus and cortex was aspirated with the vitreous-cutting instrument. The capsular bag was filled with Healon (Pharmacia and Upjohn, Kalamazoo, MI), and an AcrySof SA-60 IOL (Alcon Surgical, Fort Worth, TX) was implanted into the capsular bag. The power of the IOL implant was calculated using the Holladay 1 formula with a targeted postoperative refraction of ⫹6.00 prism diopters (PD). The scleral tunnel incision was closed with interrupted 9-0 or 10-0 Vicryl suture material, and the Healon was removed with an irrigation-aspiration instrument. A stab incision was made 1.5 to 2.0 mm posterior to the limbus. A central posterior capsulotomy ⱖ4 mm was created with the vitreous-cutting instrument while the anterior chamber was infused through the lateral stab incision. The posterior stab incision was closed with 7-0 Vicryl suture material, and the anterior stab incision was closed with 9-0 or 10-0 Vicryl suture material. Cefazolin and dexamethasone were injected subconjunctivally. One drop of 1% atropine and an antibiotic/steroid ointment were placed in the eye, and the eye was patched and covered with a shield. An examination under anesthesia/surgery form was then faxed to the DCC. The parents of the children in both treatment groups were asked to patch the unoperated eye 1 hour per day for 1 month after surgery whenever the child was awake. After the child was 8 months of age, parents were asked to patch the unoperated eye every other day during the entire time the child was awake.
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TABLE 1. Number of unilateral congenital cataracts treated in the past year by responding pediatric ophthalmologists
Response Interested in participating in randomized clinical trial Not interested in participating in randomized clinical trial Total
TABLE 2. Age of the youngest child in whom respondents had implanted an IOL Age (mo)
None
1 to 5
6 to 10
11 to 20
20
Total
8
106
14
4
1
133
20
94
4
1
0
119
⬍7 7 to 12 13 to 24 25 to 36 ⬎36 Total
Number
%
8 12 62 66 78 228
4 6 27 29 34 100.0
IOL: intraocular lens.
28
200
18
5
1
252
The patients were examined at 1 day, 1 week, 1 month, and 3 months after surgery. The patients were monitored for ocular complications at each of these examinations. If a complication was identified, a form was completed and faxed to the DCC. If reoperation was necessary, reoperation and complication narrative forms were completed and faxed to the DCC. The patients will continue to be followed up for at least 3 years.
RESULTS AAPOS Surveys A total of 260 (40%) of the 1997 and 269 (41%) of the 2001 surveys were returned. In the 1997 survey, most of the respondents (89%) reported treating at least 1 infant with a UCC during the previous year (Table 1). Six (3%) reported treating ⱖ11 infants with a UCC and 24 (10%) reported treating 6 to 11 infants with a UCC during the past year. In all, the respondents indicated that they treated at least 383 infants with a UCC during the previous year. More than one half (53%) of the respondents indicated that they would be interested in participating in a study comparing the use of a CL with IOL implant to optically correct an infant ⬍6 months of age after UCC cataract surgery. Of the 228 respondents from the 1997 survey who provided the age of the youngest child in whom they had implanted an IOL, 84 (37%) had implanted an IOL in a child ⱕ2 years old; 22 (10%) in an infant ⱕ12 months old; and 8 (4%) in an infant ⱕ6 months old (Table 2). For aphakic eyes, the majority of respondents used Silsoft (Bausch and Lomb, Rochester, NY) CLs exclusively (n ⫽ 208, 84%). Another 21 (9%) only used rigid gas-permeable CLs; the remaining respondents used both Silsoft and rigid gas permeable RGP CLs (n ⫽ 12, 5%) or another type of CL (n ⫽ 7, 3%). In the 1997 survey, age of the child (n ⫽ 52), ease of use (n ⫽ 49), increased compliance (n ⫽ 43), and ease of fit (n ⫽ 32) were the most important reasons cited for choosing a particular type of CL (Table 3). In the 2001 survey, on a scale from 1 to 10 with 1 strongly favoring IOL implant and 10 strongly favoring
TABLE 3. Most important reasons for selecting a particular type of contact lens to prescribe in UCC cases cited by responding pediatric ophthalmologists
Reason Age of child (mo) Cost of lens ($) Likelihood of loss Increased compliance Ease of fit Ease of obtaining Ease of use Improved compliance
Second Most Most Important Important
Third Most Important
Median
n
%
%
n
%
0 0 0 1 1 0 2 0
52 0 5 43 32 10 49 27
24.4 0.0 2.5 20.4 15.7 4.9 24.0 13.1
15 7.0 7 3.4 13 6.4 57 27.0 41 20.2 10 4.9 57 27.9 14 6.8
11 17 23 34 33 16 52 26
5.2 8.3 11.3 16.1 16.3 7.8 25.5 12.6
n
UCC: unilateral congenital cateract.
CL, the median score was 7.5 (median absolute deviation ⫽ 2.0) (Figure 1). Forty-one (15%) respondents chose “10” indicating a strong preference for CLs, and 11 (4%) chose “1” indicating a strong preference for IOL implants, although the remaining 208 respondents chose an intermediate preference. Fifty-eight (21%) of the respondents had implanted an IOL in an infant during the previous year. One hundred-seventy respondents (61%) indicated that they would be willing to randomize an infant (1 to 6 months old) with a UCC to treatment with an IOL implant or a CL in a National Institutes of Health–funded multicenter clinical trial. The most commonly cited concerns about CL correction were poor compliance (n ⫽ 52), high lens loss rate (n ⫽ 24), high cost (n ⫽ 21), and keratitis (n ⫽ 12). The most commonly cited concerns about IOL implant correction were poor predictability of refractive changes (n ⫽ 52), postoperative complications (n ⫽ 46), inflammation (n ⫽ 19), and technical difficulty of surgery (n ⫽ 14). Randomization Pilot Study From March 2002 to February 21, 2003, we conducted a prospective pilot study to ascertain the willingness of parents to randomize their child to treatment with a CL or IOL implant after cataract surgery and to validate our protocol. A total of 30 children were screened at nine clinical centers. Six were ineligible for the following rea-
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TABLE 4. Reasons for refusing randomization Preferred contact lens treatment Preferred IOL treatment Parental disagreement on treatment IATS surgeon out-of-network for HMO Transportation problems
3 1 1 1 1
HMO: health maintenance organization; IATS: Infant Aphakia Treatment Study; IOL: intraocular lens.
TABLE 5. Clinical findings in children randomized to treatment Clinical Finding Corneal diameter (mm) Axial length (mm) Keratometry reading (PD) FIG 1. Preferences of AAPOS members for the optical treatment of infants six months of age or younger with a visually significant unilateral cataract.
sons: prematurity (n ⫽ 2), ⱖ7 months old at the time of cataract surgery (n ⫽ 2), small cataract in the fellow eye (n ⫽ 1), and mental retardation (n ⫽ 1). Of the 24 eligible patients, the parents of 17 (71%) agreed to have their child undergo randomization. The parents of 6 eligible patients refused randomization for the reasons listed in Table 4. At the time of surgery, the mean age of the enrolled patients was 2.8 ⫾ 2.1 months. Eight patients underwent cataract surgery when they were ⬍ 7 weeks old. Eight of the patients were referred by pediatricians, 5 by pediatric ophthalmologists, and 4 by comprehensive ophthalmologists. Eleven of the patients were white, and five were black; nine were female, and eight were male. Ten of the cataracts were nuclear, two had persistent fetal vasculature, and two had posterior lentiglobus. Nine children were randomized to IOL implant correction and eight to CL correction. The cataractous eyes were slightly microphthalmic compared with their fellow eyes and had smaller corneal diameters, shorter axial lengths, and steeper corneas (Table 5). The IOL was implanted in the capsular bag in eight of the nine pseudophakic eyes. The only intraoperative complication reported was iris prolapse with a small superior iridodialysis in one patient in the IOL implant group. The only complication reported at the 1-day postoperative examination was a hyphema in one patient in the IOL implant group, which resolved by the 1-week examination. At the 1-week examination, two patients in the IOL implant group had developed pupillary membranes. A third patient in the IOL implant group was noted to have a pupillary membrane at the 3-month examination and a fourth at the 4-month examination. All four patients underwent reoperation to open the pupillary membrane. One of the patients in the IOL implant group who was noted to have a pupillary membrane at the 1-week examination subsequently developed glaucoma in the pseudophakic eye and underwent a trabeculectomy at 2 months of age. This eye was noted before surgery to be
Treated Eye (Mean ⴞ SD)
Fellow Eye (Mean ⴞ SD)
10.3 ⫾ 0.9 18.1 ⫾ 1.5 46.5 ⫾ 3.3
10.7 ⫾ 0.7 18.7 ⫾ 1.0 45.9 ⫾ 2.4
microophthalmic (corneal diameter ⫽ 9 mm) and to have persistent fetal vasculature. None of the patients in the CL group have developed a pupillary membrane, but one eye did develop glaucoma in the aphakic eye 2 months after a lensectomy and anterior vitrectomy. Before surgery, this infant was noted to have 360° of posterior embryotoxin in both eyes. In retrospect, this child should have been excluded from participating in the study because the fellow eye was not normal.
DISCUSSION The perception of pediatric ophthalmologists regarding the implantation of IOLs in children has changed radically during the past two decades. Early reports of IOL implantation during childhood emphasized the high complication rate associated with their use.8-13 As a result, some investigators recommended that IOLs be implanted only in older children with unilateral traumatic cataracts or in children who could not tolerate CLs.8-9,14 Results of many of these early case series also showed that anterior chamber and iris fixation CLs were associated with fewer complications than were posterior chamber IOL implants.9-10 In 1990, Dahan and Salmenson15 reported good visual results and relatively few complications in 80 children who underwent posterior chamber IOL implantation after cataract surgery. The investigators emphasized the importance of performing an elective posterior capsulotomy and anterior vitrectomy because of the high incidence of posterior capsular opacification in these eyes. Since then, posterior chamber IOL implants have become the implant of choice for children. By 1994, 46% of the responding AAPOS members had implanted an IOL in a child ⱕ2 years old.16 In 1996, Wilson17 suggested that posterior chamber IOL implantation had become the standard of care for children ⱖ2 years old. Results of our 2001 survey suggested that the responding AAPOS members still preferred to use CLs for optically correcting infants after unilateral cataract surgery. However, the percentage of the responding AAPOS members who had implanted an IOL
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in an infant after cataract surgery increased from 4% in 1997 to 21% in 2001, a five-fold increase. The most commonly cited concern about IOL implantation in our 2001 survey was the poor predictability of the refractive changes these eyes experience. The human eye undergoes rapid axial elongation during the first 2 years of life.18 In addition, the cornea flattens during the first 6 months.19 Although removing the crystalline lens and implanting an IOL may retard the axial elongation of an infant eye,20-21 the rapid growth of an infantile eye still results in a large myopic shift. Dahan7 reported a myopic shift of 6.93 ⫾ 3.42 D after a 7.7 year follow-up of 34 children (68 eyes) who had undergone IOL implantation during the first 18 months of life. The mean increase in axial length in these eyes was 3.59 ⫾ 1.80 mm. Wilson5 reported a myopic shift of 6.22 D after a 21 month follow-up of 16 children (32 eyes) who underwent IOL implantation during the first year of life. After a mean follow-up of 13 months, Lambert22 reported a mean myopic shift of 5.29 D in the pseudophakic eye of 11 children who underwent IOL implantation during the first 6 months of life. Others have noted large myopic shifts even in children 1 to 3 years old. Crouch23 recently reported a mean myopic shift of 5.96 D after a 6.35 year follow-up of children who underwent IOL implantation at 1 to 2 years of age. Plager24 noted a mean myopic shift of 4.60 D (range, 0.50 to 10.75) after a mean postoperative follow-up of 5.8 years in children who underwent cataract surgery at 2 to 3 years of age. In our study, our targeted undercorrection was 6 D in the children randomized to the IOL implant group. Longer-term follow-up in prospective studies, such as the proposed Infant Aphakia Treatment study, should help to establish the optimal nomogram for choosing the IOL implant power after infant cataract surgery. Another significant concern of AAPOS members in our 2001 survey was the high rate of reoperation after infant IOL implantation. Several investigators have noted a high rate of reoperation in infant eyes after IOL implantation, even after a primary posterior capsulotomy and anterior vitrectomy. Lambert22 reported that 8 of 11 eyes (83%) undergoing IOL implantation during the first 6 months of life required a reoperation. In 4 eyes (38%) a pupillary membrane or cortex reproliferation had to be excised from the visual axis. In 2 other eyes the iris had to be swept from the surgical incision site. In addition, 2 eyes developed glaucoma and underwent glaucoma surgery. Plager6 reported that 12 of 15 eyes (80%) developed pupillary membranes obstructing the visual axis after IOL implantation during the first 6 months of life. In addition, 2 of these eyes had to undergo a second operation to clear the visual axis, and 1 eye developed glaucoma. After follow-up of 12 months or longer, Wilson5 reported a 21% incidence of pupillary membranes requiring reoperation in a cohort of children undergoing IOL implantation. In addition, 3 eyes (9%) developed glaucoma, and 1 eye had to undergo reoperation to sweep the iris from the surgical incision site.
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Poor compliance was the most commonly identified problem with CL correction. Assaf et al25 reported that only 44% of children in Saudi Arabia with unilateral aphakia were wearing their CL when they returned for followup. Poor compliance in children with unilateral aphakia is multifactorial, but contributing factors include the high cost of CLs, the inability of children to discern a visual benefit from CL use if the fellow eye has normal vision, and the difficulty of caregivers inserting and removing CLs in a small child. The loss of CLs was cited as another important problem with CL wear. Amos et al26 reported a lost lens rate of 2.4 CLs/eye/y in a small series of aphakic children wearing rigid gas-permeable CLs. Holmstrom et al27 reported dispensing, on average, 22.8 soft CLs/eye/y for aphakic children. They attributed the high turnover rate of CLs during the first 6 months of treatment to the frequent parameter changes and the initial difficulties that parents have handling CLs. CL wear may be prohibitively expensive for some families, particularly in developing countries.28 In the United States, many health insurance plans do not cover the cost of CLs even when they are worn to correct aphakia. The incidence of keratitis in children wearing CLs for aphakia is not known. Although anecdotal reports would suggest that keratitis occurs more often in the setting of Silsoft CLs worn on an extended basis, a recent report by Cavanaugh et al29 suggested that CLs with a high gas transmissibility (DK) may be associated with a lower risk of bacterial keratitis. Because Silsoft CLs have the highest DK of any commercially available CL, this may account for the relatively low incidence of bacterial keratitis in aphakic children wearing Silsoft CLs. The percentage of AAPOS members who indicated that they would be willing to participate in a study comparing CL correction with IOL implantation in infants increased from 53% in our 1997 survey to 61% in our 2001 survey. Nonetheless, the majority of AAPOS members still favored a CL correction for an infant ⬍7 months of age with a UCC. When asked to indicate their preference on a scale of 1 to 10 with 1 strongly favoring an IOL implant and 10 strongly favoring a CL, the median score was 7.5. However, the fact that 61% of AAPOS members were willing to enroll an infant with a UCC into a randomized clinical trial comparing these two treatments suggest that nearly two thirds were undecided as to which treatment is best. Parents had equipoise regarding the use of IOL implants and CLs once the relative advantages and disadvantages of each were explained to them. In our pilot study, the parents of 17 of 24 (71%) eligible patients agreed to be randomized to either treatment after cataract surgery. In the Cryotherapy for Retinopathy of Prematurity (CRYOROP) study, the parents of 4,901 of 5,822 (84%) eligible patients consented to randomization.30 In our study, parents were slightly less willing to be randomized in our study than in the CRYO-ROP study. The lower rate of randomization in our study may reflect the fact that the
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children in our study were all outpatients, and their parents may have had more time to consider the two treatment options. In some cases, parents declined randomization after extensively researching the two treatment options on the Internet or consulting with other pediatric ophthalmologists; this would not have been possible for the parents of the children in the CRYO-ROP study. Parents often chose one treatment based on the compatibility of the treatment with their lifestyle. Although the innovative aspect of IOL implantation was appealing to certain parents initially, once they understood the risks and benefits of both treatment options, innovation was not a significant factor in the decision making process for most parents.31 The complication rate in our pilot study was similar to what has been reported previously. Pupillary membranes or cortex reproliferation occurred within 6 months or less in four of the nine (45%) children randomized to IOL implantation. In three of four cases, reoperation was necessary during the first 3 postoperative months. One child in the aphakic group and one in the pseudophakic group developed glaucoma. Although it has been suggested that IOL implantation may decrease the risk of glaucoma in aphakic eyes, this likely reflects a selection bias in the children who have undergone IOL implantation in the past.32,33 Both of the patients in our study who developed glaucoma had a risk factor for glaucoma (ie, one child had persistent fetal vasculature and microphthalmos and the other had 360° of posterior embryotoxin). As children increasingly undergo IOL implantation during infancy, it is becoming clear that glaucoma will develop in some of these eyes.5,22 The results of our pilot study suggested that both pediatric ophthalmologists and parents have equipoise regarding the use of an IOL implant versus a CL to optically correct an infant ⬍7 months old with a UCC after cataract surgery. We hope to conduct a large multicenter clinical trial to more carefully ascertain the risks and benefits of these two treatments. References 1. Taylor D. Congenital cataract: the history, the nature and the practice. Eye 1998;12:9-36. 2. Wright KW. Lens abnormalities. In: Wright KW, Spiegel PH, editors. Pediatric ophthalmology and strabismus. New York (NY): Springer-Verlag; 2003. p. 469. 3. Ma JJK, Morad Y, Mau E, Brent HP, Barclay R, Levin AV. Contact CLs for the treatment of pediatric cataracts. Ophthalmology 2003; 110:299-305. 4. Lambert SR, Lynn M, Drews-Botsch C, Fawcett S, Loupe D, Plager DA, et al. A comparison of grating visual acuity, strabismus, and reoperation outcomes among children with aphakia and pseudophakia after unilateral cataract surgery during the first six months of life. J AAPOS 2001;5:70-5. 5. Wilson ME, Peterseim MW, Englert JA, Lall-Trail JK, Elliott LA. Pseudophakia and polypseudophakia in the first year of life. J AAPOS 2001;5:238-45. 6. Plager DA, Yang S, Neely D, Sprunger D, Sondhi N. Complications in the first year after cataract surgery with and without IOL in infants and older children. J APPOS 2002;6:9-14.
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