Early detection and intervention in the management of childhood cataracts is important for the treatment of deprivational amblyopia and successful visual rehabilitation. Implantation of an intraocular lens (IOL) at the time of cataract surgery has become increasingly accepted in the pediatric population and is considered the standard of care in older children.1 However, studies demonstrate that there are continuing concerns regarding the long-term outcomes and complications of IOLs in children younger than 2 years.2,3
Although the Infant Aphakia Treatment Study (IATS) studied the use of IOLs in infants younger than 7 months, few studies have provided long-term outcomes of IOLs implanted specifically in children aged 7 to 24 months. Data from 5 years of follow-up from the IATS found a higher risk of adverse events in patients aged 0 to 7 months who received an IOL compared to patients who were left aphakic, but did not include patients aged 7 months or older.4
The purpose of our study was to present the long-term outcome of IOLs in pediatric patients who received cataract surgery aged 7 months to younger than 24 months. To our knowledge, only one such study looking at this age group has been published to date.5
Patients and Methods
Prior to initiating this study, institutional review board approval was obtained from the Baylor College of Medicine for the retrospective study. A comprehensive database search of our electronic medical record was performed to identify all patients aged 7 months to younger than 24 months who had cataract surgery with placement of an IOL between August 2002 and March 2015. Patients were excluded if follow-up was less than 12 months. All surgeries were performed by a single surgeon (KGY).
Axial length and keratometry were measured in the operating room using immersion A-scan ultrasonography and a handheld keratometer. The surgeon used a bimanual surgical technique with a vitrectomy handpiece and irrigating cannula, each placed through a paracentesis. A vitrectorhexis was performed with the vitrectomy handpiece. The lens material was removed using the bimanual technique. After the lens material was aspirated, one paracentesis was enlarged and an AcrySof SN60AT or MA60AC IOL (Alcon Laboratories, Inc., Fort Worth, TX) was folded and centered in the bag (SN60AT or MA60AC) or in the sulcus (MA60AC). For patients who received a posterior capsulotomy, a sclerotomy was made with the MVR blade. The vitrectomy handpiece was introduced through the sclerotomy with an irrigating cannula through the paracentesis and a posterior capsulotomy was performed using cutting and aspiration. A thorough anterior vitrectomy was performed for 3 minutes. Postoperatively, patients were treated with topical 1% prednisolone acetate and 0.5% moxifloxacin (Vigamox; Alcon Laboratories, Inc.) drops and the prednisolone acetate was tapered over 4 to 6 weeks. Target postoperative refraction was +5.00 diopters (D) for patients aged 7 to 12 months and +4.00 D for those aged 12 to 24 months. Residual refractive error was corrected with spectacles at 4 weeks after surgery, aiming for overcorrection by +2.00 D until the age of 2 years, when the child received bifocals.6
The medical records were reviewed for best corrected visual acuity (BCVA), cycloplegic refraction, intraocular pressure, presence of strabismus and stereopsis, and slit-lamp examination findings at each follow-up visit. Patient parameters reviewed included sex, ethnicity, age at surgery, location of cataract, cataract laterality, presence and laterality of amblyopia, type and angle of strabismus, patching compliance, IOL power, and goal refraction. Type of cataract was classified according to the IATS criteria.7 Intraoperative complications and adverse events were recorded using similar criteria to those used in the IATS study.8–10 Significant strabismus was defined as a deviation greater than 10 prism diopters (PD). Poor patching compliance was defined as patching less than 50% of the recommended patching time.
Statistical analysis was performed using SPSS software (version 21; SPSS, Inc., Chicago, IL). Confidence interval level was 95%. A P value of less than .05 was considered statistically significant. Demographic and clinical variables were summarized with descriptive statistics. Visual acuity was converted to logMAR for analysis. Counting fingers vision was converted to 1.88 logMAR (20/1500) and hand motions was converted to 2.30 logMAR (20/4000).11 The two-tailed paired samples t test was used for comparing the means of two variables. Chi-square analysis was used for categorical data. Multiple logistic regression models and Pearson correlation analysis were used to analyze the relationship between variables. Analysis was performed using the most recent BCVA.
A total of 35 patients who had cataract surgery with IOL implantation from ages 7 months to younger than 24 months were found through the medical record search. Eight patients were excluded due to inadequate follow-up; 27 patients met the criteria for inclusion. Although 3 patients had bilateral cataracts, only 1 patient required surgery in both eyes. Thus, a total of 27 patients (28 eyes) were included for review.
The mean age at diagnosis of the cataract was 13 ± 5.6 months (range: 5.3 to 23.9 months). The mean age at the time of cataract surgery with IOL implantation was 14.4 ± 5.6 months (range: 7.2 to 23.6 months), and the mean length of follow-up was 62.7 ± 41.7 months (range: 12.2 to 144.4 months). Other patient demographics are detailed in Table 1.
Data for Pediatric Patients Aged 7 to 24 Months Receiving Primary IOL Implantation
At the most recent follow-up, 7 of 28 eyes (25%) were only able to demonstrate fix and follow during visual acuity testing. The mean BCVA of the remaining patients was 1.02 ± 0.72 logMAR (20/209; range: 0.00 to 2.30 logMAR); if the patients with bilateral cataracts were excluded, mean BCVA was 1.12 ± 0.17 logMAR (20/260; range: 0.00 to 2.30 logMAR). Ten of 28 eyes (35.7%) had visual acuity of 20/200 or worse (Table 2). The average age at the most recent visit for the patients who could only demonstrate fix and follow was 32.3 ± 10.3 months compared to 92.4 ± 38.9 months for the remaining patients.
Preoperative and Postoperative Characteristics of Patients Aged 7 to 24 Months Receiving Primary IOL Implantation
Intraoperative events occurred in 2 of 28 eyes (7.1%); in both cases, there was extension of the anterior vitrectorhexis peripherally. The IOL was placed in the sulcus in both patients. In 1 patient, the posterior capsulotomy was not performed at the time of the initial surgery.
Adverse events occurred in 7 eyes (25%), with 6 cases of visual axis opacification and 1 case of pupillary block glaucoma. All 7 of these eyes required additional intraocular surgery. Of the 6 patients (21.4%) who had visual axis opacification, all but 1 had a posterior capsulotomy and anterior vitrectomy at the time of the initial surgery; all 6 patients were treated with a surgical posterior capsulotomy with anterior vitrectomy to clear the visual axis opacification. The visual axis opacification developed an average of 9.8 ± 7.2 months (range: 2.6 to 22.9 months) after initial surgery. The average age of initial cataract surgery for the visual axis opacification group was 14.6 ± 6.2 months compared to 14.3 ± 5.6 months for the patients who did not develop visual axis opacification. No eyes developed recurrent visual axis opacification.
One patient developed pupillary block glaucoma 4 days after surgery. She was taken back to the operating room and found to have 360 degrees posterior synechiae, which were lysed. Of note, this family was not compliant with the use of the postoperative steroid drops in the first postoperative week. This same patient had persistent iris corectopia and dense amblyopia at the most recent follow-up, but developed no other complications and did not go on to develop persistent glaucoma.
Strabismus greater than 10 PD was observed in 0 of 3 of patients with bilateral cataracts and 7 of 24 patients with unilateral cataract, with 7 of 27 (25.9%) total patients electing to proceed with strabismus surgery during the study time period, 3 for exotropia and 4 for esotropia. Stereopsis was able to be tested on 19 (18 in the unilateral group and 1 in the bilateral group) of the 27 patients at the most recent follow-up. Nine of the patients with unilateral cataract (37.5%) and 1 of the patients with bilateral cataract (33%) had stereoacuity better than 800 seconds of arc using the Titmus fly test. Stereopsis was positively correlated with better vision (P = .02).
One patient developed an epithelial inclusion cyst at the sclerotomy site that was excised. No eyes developed retinal detachment or endophthalmitis and no additional patients developed glaucoma.
All of the patients in our study were treated for amblyopia with patching. Poor patching compliance was observed in 16 of 24 (66.7%) patients with unilateral cataract and 2 of 3 (66.7%) patients with bilateral cataract. Patients who had good compliance with patching were four times more likely to have better vision outcomes (odds ratio: 1.25; 95% confidence interval: 0.80 to 1.59; P = .001); if the bilateral patients were excluded, this was also the case (odds ratio: 1.30; 95% confidence interval: 0.9 to 1.8; P = .001). The average visual acuity for patients with good patching was better than in patients with poor patching compliance (20/130 vs 20/300). This result is not statistically significant (P = .20), probably due to the small sample size. If the patients with bilateral cataracts were excluded, this trend remained the same (20/140 vs 20/418; P = .12).
Average target refraction for the patients was +3.74 ± 1.20 D. Average refraction at 1 month after surgery was +3.41 ± 2.00 D, giving an average deviation from target refraction of −0.33 D. Figures 1–2 show correlation data for initial, final, and target refraction. There was a wide range in achievement of target refraction (Figure 2), with 21.4% and 67.9% of patients within +0.50 and +1.00 D of target refractive error, respectively. There was an average shift of −4.10 ± 2.70 D (range: −11.00 to +0.75 D) over the study period, with an average shift of −1.16 ± 1.10 D per year and 67% of patients having less than −1.00 D shift per year.
Scatter plot with fitted linear regression line (solid line) of initial versus final spherical refractive error at most recent visit. The dotted lines indicate 95% confidence interval. Myopic shift was observed in the majority of patients. D = diopters
Target spherical refractive error versus achieved spherical refractive error. Scatterplot with fitted linear regression line. D = diopters
Currently, placement of an IOL at the time of initial cataract surgery is considered the standard of care in patients older than 2 years.1 Although primary IOL implantation has become increasingly more common in patients younger than 2 years,2,3 concerns about adverse events and refractive changes continue to be barriers to IOL implantation in this younger population.12 The prospective IATS delineated the concerns for patients younger than 7 months receiving primary IOL implantation and found an increased risk for adverse events with no significant difference in visual outcomes when comparing primary IOL implantation to aphakia with contact lens use.
A 2001 survey of American Association for Pediatric Ophthalmology and Strabismus (AAPOS) and American Society of Cataract and Refractive Surgery (ASCRS) found that the median minimum age of IOL implantation was 1.8 years for AAPOS and 4 years for ASCRS, indicating that the most popular minimum age for IOL implantation in the United States was still close to 2 years or older at the time of that survey.3 More recently, a 2009 study by the British Isles Congenital Cataract Interest Group found that IOL implantation was performed in 65% of pediatric patients younger than 2 years receiving surgery in the British Isles.2 In a more recent study, Struck observed patients aged 7 to 24 months who had undergone IOL implantation and found favorable visual outcomes and a lower rate of adverse events compared to patients younger than 7 months.5
In our study, the mean BCVA at the most recent follow-up was 1.02 logMAR (20/209). Similar to the IATS study,7 several of our patients (35.7%) had visual acuity worse than 20/200. Other studies by Magli et al.13 and Lu et al.14 have demonstrated final BCVA values ranging from 0.61 (20/81) to 0.91 (20/166) in patients aged 2 to 21 months. Struck followed long-term visual outcomes in patients aged 7 to 22 months at the time of surgery and reported a mean BCVA of 0.29 logMAR (20/40) in 14 eyes, which was significantly better than in previously published studies.5 Compliance with patching was not described in his study. Amblyopia has been demonstrated to be the main limiting factor in the improvement of vision in patients with unilateral pediatric cataract15 and is believed to be the main limitation to vision improvement in many of our patients. Similar conclusions were found by the British Isles Congenital Cataract Interest Group, in which odds of better vision with IOL implantation were noted in patients younger than 2 years if they had bilateral cataracts, but not unilateral cataracts.2 More than 60% of our patients demonstrated poor patching compliance and, as expected, visual acuity was better in the patients who had better patching compliance.16,17
Selecting an IOL and target refraction in young pediatric patients can be difficult. In general, most surgeons elect to target postoperative hyperopia in this age group, anticipating myopic development as the eye undergoes emmetropization.3 Surveys of AAPOS and ASCRS members performed in 2001 reported the most common target refractions in this age group to be mild hyperopia (> 0.00 D but < 3.00 D) and moderate hyperopia (≥ 3.00 D but < 7.00 D).3 The mean target postoperative refraction in our study for this age group was +3.75 ± 1.30 D and the mean spherical equivalent at the 1-month follow-up visit was +3.41 ± 2.00 D, with the mean deviation from target refraction being −0.33 D. This difference is less than the mean prediction error of 0.90 D reported by Struck 1 month after surgery, which is similar to previously published data on children.5
Emmetropization is a concern in pediatric patients and is one reason there is hesitancy in placing IOLs in young patients. Lu et al. studied patients who were aged 6 to 12 months when they underwent cataract surgery and found the greatest myopic shift to occur in the first year after surgery.14 The authors found myopic shift to be 5.15 ± 2.08 D in the first year after surgery and cumulative myopic shift to be 6.46, 7.54, and 7.92 D after 24, 36, and 48 months, respectively. In his study including patients aged 7 to 22 months, Struck calculated a rate of refractive growth of −5.80 ± 3.09 D for patients at three times the initial age at surgery.5 McClatchey et al. calculated a mean myopic shift in pseudophakic eyes of 7.80 D over a course of 7.76 years when surgery was performed at age 6 to 12 months and 4.81 D in patients aged 12 to 24 months at time of surgery.18 In a study by Plager et al., children operated on between the ages of 2 to 3 years had an average myopic shift of 4.60 D over a mean of 5.8 years of follow-up.19 Although there was a wide range of myopic shift, the average myopic shift in our patients was 4.03 ± 2.70 D with an average shift per year of 1.16 ± 1.10 D, which is similar to these published results.
Strabismus occurs commonly in pediatric patients with cataracts.5,20,21 In our study, the rate of strabismus was 70.4%, consistent with previous studies.12 Gross stereopsis was found in 11 of the 17 patients in our study (64.7%) who were able to be tested. Although stereopsis in our patients was not as high as the values found in studies of patients who were older than 2 years,1 the results are still comparatively better than those in patients younger than 7 months undergoing surgery, where only 25% of patients demonstrated stereopsis.22 In our patients, stereopsis was positively correlated with visual acuity (P = .02), which was also found in the IATS.22 Notably, the patient with the best stereopsis also had the best visual outcomes at the most recent follow-up visit.
As in other studies, the most common adverse event was visual axis opacification, which occurred in 6 of our eyes (21.4%).4,5,13,14,23 In addition, 1 patient developed pupillary block glaucoma 1 week after the initial surgery; this was related to posterior synechiae, which was believed to develop due to poor compliance in drop use postoperatively. Because children younger than 2 years are prone to postoperative inflammation, the use of topical steroids postoperatively is imperative.24,25 No additional patients developed glaucoma over the study period. Our rate of adverse events was similar to that found in Struck's study5 and lower than that reported in both the IATS pseudophakic and aphakic patient groups.24 Similar rates of adverse events were also found by Greenwald and Glaser when looking at older patients between 2 and 16 years at time of surgery.1
Our study was limited by its retrospective nature and small sample size. As a result, follow-up was not consistent with all patients and some data points were not available. The young age of our patient population limited our ability to measure quantitative visual acuity in some patients.
IOL implantation in our patients aged 7 to 24 months was associated with few surgical complications. The most common adverse event was the development of visual axis opacification. Amblyopia likely limits vision improvement in many of the patients with unilateral cataracts and myopic shift should be considered when calculating postoperative target refraction for these patients. Our study suggests that primary IOL implantation can be a safe and effective intervention for treatment of cataracts in patients aged 7 to 24 months.
- Greenwald MJ, Glaser SR. Visual outcomes after surgery for unilateral cataract in children more than two years old: posterior chamber intraocular lens implantation versus contact lens correction of aphakia. J AAPOS. 1998;2:168–176. doi:10.1016/S1091-8531(98)90009-X [CrossRef]
- Solebo AL, Russell-Eggit I, Nischal KK, et al. Cataract surgery and primary intraocular lens implantation in children < or = 2 years old in the UK and Ireland: finding of national surveys. Br J Ophthalmol. 2009;93:1495–1498. doi:10.1136/bjo.2009.160069 [CrossRef]
- Wilson ME Jr, Bartholomew LR, Trivedi RH. Pediatric cataract surgery and intraocular lens implantation: practice styles and preferences of the 2001 ASCRS and AAPOS memberships. J Cataract Refract Surg. 2003;29:1811–1820. doi:10.1016/S0886-3350(03)00220-7 [CrossRef]
- Plager DA, Lynn MJ, Buckley EG, Wilson ME, Lambert SRInfant Aphakia Treatment Study Group. Complications in the first 5 years following cataract surgery in infants with and without intraocular lens implantation in the Infant Aphakia Treatment Study. Am J Ophthalmol. 2014;158:892–898. doi:10.1016/j.ajo.2014.07.031 [CrossRef]
- Struck MC. Long-term results of pediatric cataract surgery and primary intraocular lens implantation from 7 to 22 months of life. JAMA Ophthalmol. 2015;133:1180–1183. doi:10.1001/jamaophthalmol.2015.2062 [CrossRef]
- Eibschitz-Tsimhoni M, Archer SM, Del Monte MA. Intraocular lens power calculation in children. Surv Ophthalmol. 2007;52:474–482. doi:10.1016/j.survophthal.2007.06.010 [CrossRef]
- Wilson ME, Trivedi RH, Morrison DG, et al. The Infant Aphakia Treatment Study: evaluation of cataract morphology in eyes with monocular cataracts. J AAPOS. 2011;15:421–426. doi:10.1016/j.jaapos.2011.05.016 [CrossRef]
- Lambert SR, Lynn MJ, Infant Aphakia Treatment Study Group et al. Comparison of contact lens and intraocular lens correction of monocular aphakia during infancy: a randomized clinical trial of HOTV optotype acuity at age 4.5 years and clinical findings at age 5 years. JAMA Ophthamol. 2014;132:676–682. doi:10.1001/jamaophthalmol.2014.531 [CrossRef]
- Infant Aphakia Treatment Study Group. The Infant Aphakia Treatment Study: design and clinical measures at enrollment. Arch Ophthalmol. 2010;128:21–27. doi:10.1001/archophthalmol.2009.350 [CrossRef]
- Plager DA, Lynn MJ, Buckley EG, Wilson ME, Lambert SRInfant Aphakia Treatment Study Group. Complications, adverse events, and additional intraocular surgery 1 year after cataract surgery in the Infant Aphakia Treatment Study. Ophthalmology. 2011;118:2330–2334. doi:10.1016/j.ophtha.2011.06.017 [CrossRef]
- Schulze-Bonsel K, Feltgen N, Burau H, Hansen L, Bach M. Visual acuities “hand motion” and “counting fingers” can be qualified with the Freiburg Visual Acuity Test. Invest Ophthalmol Vis Sci. 2006;47:1236–1240. doi:10.1167/iovs.05-0981 [CrossRef]
- Lambert SR, Lynn M, Drews-Botsch C, et al. Intraocular lens implantation during infancy: perceptions of parents and the American Association for Pediatric Ophthalmology and Strabismus members. J AAPOS. 2003;7:400–405. doi:10.1016/j.jaapos.2003.08.004 [CrossRef]
- Magli A, Forte R, Carelli R, Rombetto L, Magli G. Long-term outcomes of primary intraocular lens implantation for unilateral congenital cataract. Semin Ophthalmol. 2016;31:548–553.
- Lu Y, Ji YH, Luo Y, Jiang YX, Wang M, Chen X. Visual results and complications of primary intraocular implantation in infants aged 6 to 12 months. Graefes Arch Clin Exp Ophthalmol. 2010;248:681–686. doi:10.1007/s00417-010-1310-4 [CrossRef]
- Repka MA. Visual rehabilitation in pediatric aphakia. Dev Ophthalmol. 2016;57:49–68. doi:10.1159/000442501 [CrossRef]
- Drews-Botsch CD, Celano M, Kruger S, Hartmann EEInfant Aphakia Treatment Study Group. Adherence to occlusion therapy in the first six months of follow-up and visual acuity among participants in the Infant Aphakia Treatment Study (IATS). Invest Ophthalmol Vis Sci. 2012;53:3368–3375. doi:10.1167/iovs.11-8457 [CrossRef]
- Zwaan J, Mullaney PB, Awad A, al-Mesfer S, Wheeler DT. Pediatric intraocular lens implantation: surgical results and complications in more than 300 patients. Ophthalmology. 1998:105:112–119. doi:10.1016/S0161-6420(98)91568-8 [CrossRef]
- McClatchey SK, Dahan E, Maselli E, et al. A comparison of the rate of refractive growth in pediatric aphakic and pseudophakic eyes. Ophthalmology. 2000;107:118–122. doi:10.1016/S0161-6420(99)00033-0 [CrossRef]
- Plager DA, Kipfer H, Sprunger DT, Sondhi N, Neely DE. Refractive change in pediatric pseudophakia: 6-year follow-up. J Cataract Refract Surg. 2002;28:810–815. doi:10.1016/S0886-3350(01)01156-7 [CrossRef]
- Spanou N, Alexopoulos L, Manta G, Tsamadou D, Drakos H, Paikos P. Strabismus in pediatric lens disorders. J Pediatr Ophthalmol Strabismus. 2011;48:163–166. doi:10.3928/01913913-20100618-05 [CrossRef]
- Weisberg OL, Sprunger DT, Plager DA, Neely DE, Sondhi N. Strabismus in pediatric pseudophakia. Ophthalmology. 2005;112:1625–1628. doi:10.1016/j.ophtha.2005.06.002 [CrossRef]
- Hartmann EE, Stout AU, Lynn MJ, et al. Stereopsis results at 4.5 years of age in the Infant Aphakia Treatment Study. Am J Ophthalmol. 2015;159:64–70. doi:10.1016/j.ajo.2014.09.028 [CrossRef]
- Young TL, Bloom JN, Ruttum M, Sprunger DT, Weinstein JMAAPOS Research Committee. The IOLAB, Inc pediatric intraocular lens study. J AAPOS. 1999;3:295–302. doi:10.1016/S1091-8531(99)70026-1 [CrossRef]
- Kumar P, Lambert SR. Evaluating the evidence for and against the use of IOLs in infants and young children. Expert Rev Med Devices. 2016;13:381–389. doi:10.1586/17434440.2016.1153967 [CrossRef]
- Raina UK, Mehta DK, Monga S, Arora R. Functional outcomes of acrylic intraocular lenses in pediatric cataract surgery. J Cataract Refract Surg. 2004;30:1082–1091. doi:10.1016/j.jcrs.2003.11.027 [CrossRef]
Data for Pediatric Patients Aged 7 to 24 Months Receiving Primary IOL Implantation
|Age at IOL implantationa||14.4 ± 5.6|
| Range||7.2 to 23.6|
|Mean length of follow-upa||62.7 ± 41.7|
| Range||12.2 to 144.4|
| Male||8 (29.6%)|
| Female||19 (70.4%)|
| Hispanic||14 (51.9%)|
| White||9 (33.3%)|
| African American||4 (14.8%)|
| Unilateral||24 (88.9%)|
| Bilateral||3 (11.1%)|
| Posterior lentiglobus||10 (35.7%)|
| Nuclear||6 (21.4%)|
| Posterior polar||5 (17.9%)|
| Anterior polar||2 (7.1%)|
| Posterior subcapsular||2 (7.1%)|
| Syndromicb||2 (7.1%)|
| Persistent fetal vasculature||1 (3.6%)|
Preoperative and Postoperative Characteristics of Patients Aged 7 to 24 Months Receiving Primary IOL Implantation
|Patient||Age (mo)/Sex||Eye||Cataract Location||Laterality||IOL Power (D)||Target Refraction (D)||Postop Refraction (SE)||Final BCVA||Adverse Events|
|1||7.2/F||OD||Posterior lenticonus||U||28.50||5.00||5.50||20/40+2||Visual axis opacification|
|5||8.6/F||OD||Posterior lenticonus||U||26.50||5.00||5.00||20/500||Pupillary block glaucoma corectopia|
|6||8.7/M||OD||Nuclear||U||30.00||4.00||8.00||F/F||Visual axis opacification|
|15||13.9/F||OD||PFV||U||21.50||3.00||2.25||20/400||Visual axis opacification|
|17||14.6/M||OS||Posterior subcapsular||U||26.00||3.50||3.13||20/150||Visual axis opacification|
|21||19.3/F||OS||Total||U||23.00||3.00||1.00||HM||Visual axis opacification|
|27||23.6/F||OD||Nuclear||U||15.00||4.00||2.75||CF||Visual axis opacification|