Dose-Response of Primary Bilateral Medial Rectus Resection in Infantile Exotropia.

PURPOSE: To evaluate the dose-response relationship for primary bilateral medial rectus resection in children with exotropia, based on outcomes with this procedure. METHODS: Dose-response at both distance and near were calculated as prism diopters correction per millimeter (PD/mm) of rectus resection. All surgeries were performed under general anesthesia through a fornix incision, using doubled-armed 6-0 polyglactin sutures. The resection amount ranged from 5 to 8 mm in each eye, according to the surgical dosage based on the largest angle of preoperative deviation. RESULTS: The mean surgical dose-response for all procedures was 2.83 ± 1.03 PD/mm of resection at distance and near. The overall success rate was 53% at the final examination after a mean follow-up of 21.9 months. Patients with moderate angles (25 to 45 PD) had a higher success rate than those with 50 PD or greater deviation. CONCLUSIONS: Primary bilateral medial rectus resection should be considered as a surgical alternative in childhood exotropia, particularly for moderate and constant deviations. [J Pediatr Ophthalmol Strabismus. 2022;59(1):24-27.].

Normative Values, Testability, and Validity for a New Preferential Looking Stereoacuity Test.

Introduction: Age norms and testability for 3-5 year old children have been reported for the PASS III stereotest using a pointing response. We aimed to expand the normative data to children as young as 6 months, assess testability, and evaluate validity use of the PASS III as a preferential-looking test for younger children and children with special needs. Methods: 68 control children, 362 children with eye conditions, and 167 children with special needs were tested with the PASS III. Percent testable was calculated for children with and without special needs, normal tolerance limits were determined, and test validity was assessed. Results: In controls, mean PASS III stereoacuity improved from 371 arcsec at 12 months to 174 arcsec at 24 months, and 87 arcsec at 36 months. Testability in the 12, 24, and 36 months age groups were 81%, 87%, and 97% respectively and 92% for special needs children. Comparison to previously published norms and testing in a known nil stereoacuity cohort supported PASS III test validity. Compared to gold standard stereoacuity tests, accuracy of the PASS was 89%. Conclusion: Overall, preferential-looking tests using the PASS III provide a sensitive and specific measure of stereoacuity with high testability for young children and children with special needs.

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

OBJECTIVES: To report the myopic shift in the aphakic eyes of a cohort of children who underwent unilateral cataract surgery during infancy and were then followed longitudinally for 10.5 years. METHODS: One-half of the children enrolled in the Infant Aphakia Treatment Study (IATS) were randomized to aphakia and contact lens correction after unilateral cataract surgery. They then underwent ocular examinations using standardized protocols at prescribed time intervals until age 10.5 years. RESULTS: Thirty of 57 children randomized to aphakia remained aphakic at age 10.5, having undergone unilateral cataract surgery at a median age of 1.6 (IQR: 1.1-3.1) months. The median refractive error (RE) in the 57 eyes randomized to aphakia immediately after cataract surgery was 19.01 D (IQR: 16.98-20.49) compared to 10.38 D (IQR: 7.50-14.00) for the 30 eyes that remained aphakic at age 10.5 years. The mean change in RE in aphakic eyes was -2.11 D/year up to age 1.5 years, -0.68 D/year from 1.5 to 5.0 years, and -0.35 D/year from age 5 to 10.5 years. At age 10.5 years, 18 patients continued to wear a contact lens correction (silicone elastomer, n=6; gas permeable, n=6; hydrogel, n=5; and silicone hydrogel, n=1) (median RE, 12.50 D), 9 wore only spectacles (median RE, 4.00 D), and 4 wore no correction (median RE, 11.25 D) to correct their aphakic eye. CONCLUSIONS: The RE in aphakic eyes decreased by 44% from infancy to age 10.5 years. About two-thirds of children who remained aphakic at age 10.5 years continued to wear a contact lens.

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

PURPOSE: To report the change in globe axial length (AL) from the time of unilateral cataract surgery at age 1-7 months to age 10.5 years for infants enrolled in the Infant Aphakia Treatment Study, and to compare AL growth of operated eyes with that of fellow unoperated eyes. DESIGN: Comparative case series. METHODS: AL growth was analyzed relative to treated vs fellow eye, contact lens (CL) vs intraocular lens (IOL), visual acuity (VA) outcome, and the need for surgery for visual axis opacification. Eyes with glaucoma or glaucoma suspect were excluded from the primary analysis but reported separately. RESULTS: Fifty-seven patients have reliable AL data available at both visits. AL was shorter in treated eyes preoperatively (P < .0001) and at 10.5 years of age (P = .021) but AL growth was not different (4.7 mm, P = .99). The growth (70.2% up to age 5 and 29.8% from age 5 to 10.5) was similar in the CL and the IOL group (P = .79). Eyes grew 4.4 mm when visual acuity (VA) was better than 20/200, and 5.2 mm when VA was 20/200 or worse (P = .076). Eyes receiving additional surgery grew more than eyes not receiving additional surgery (P = .052). Patients with glaucoma showed significantly more eye growth (7.3 mm) than those without glaucoma (4.7 mm) and glaucoma suspects (5.1 mm) (P < .05). CONCLUSIONS: Eyes with glaucoma or poor VA often grew longer than the fellow eye. Overall, treated eyes grew similarly in the IOL and CL groups and also kept pace with the growth of the fellow eyes.

Long-term Effect of Intraocular Lens vs Contact Lens Correction on Visual Acuity After Cataract Surgery During Infancy: A Randomized Clinical Trial.

Importance: Although intraocular lenses (IOLs) are often implanted in children, little is known whether primary IOL implantation or aphakia and contact lens correction results in better long-term visual outcomes after unilateral cataract surgery during infancy. Objective: To compare long-term visual outcomes with contact lens vs IOL correction following unilateral cataract surgery during infancy. Design, Setting, and Participants: This multicenter randomized clinical trial enrolled 114 infants with a unilateral congenital cataract who underwent cataract surgery with or without primary IOL implantation between 1 and 6 months of age. Data on long-term visual outcomes were collected when the children were age 10.5 years (July 14, 2015, to July 12, 2019) and analyzed from March 30 through August 6, 2019. Interventions: Intraocular lens implantation at the time of cataract surgery. Main Outcomes and Measures: Best-corrected visual acuity using the electronic Early Treatment Diabetic Retinopathy Study (E-ETDRS) testing protocol. Analysis was performed on an intention-to-treat basis. Results: Best-corrected visual acuity was measured at age 10.5 years for 110 of the 114 patients (96%) enrolled as infants. The participants included 58 girls (53%) and 52 boys (47%). Overall, 27 of the children (25%) had good (logMAR 0.30 [Snellen equivalent, 20/40] or better) visual acuity in the treated eye (12 [22%] in the IOL group and 15 [27%] in the aphakia group), but 50 children (44%) had a visual acuity of logMAR 1.00 (Snellen equivalent, 20/200) or worse (25 [44%] in the IOL group and 25 [44%] in the aphakia group). The median logMAR acuity in the treated eye was similar in children randomized to receive an IOL at the time of cataract extraction (0.89; interquartile range [IQR], 0.33-1.43 [Snellen equivalent, 20/159]) and those who remained aphakic (0.86; IQR, 0.30-1.46 [Snellen equivalent, 20/145]) (IQR, 0.30-1.46; P = .82). Although the overall difference in median visual acuity between the 2 groups was small, the estimate was imprecise (99% CI for the difference in medians was -0.54 to 0.47). Conclusions and Relevance: As in previous phases of the study, visual acuity outcomes were highly variable with only 27 children (25%) achieving excellent visual acuity in their treated eye and 50 children (44%) having poor vision in the treated eye. Implanting an IOL at the time of cataract extraction was neither beneficial nor detrimental to the visual outcome. Trial Registration: ClinicalTrials.gov Identifier: NCT00212134.

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

PURPOSE: To report the myopic shift at 5 years of age after cataract surgery with intraocular lens (IOL) implantation for infants enrolled in the Infant Aphakia Treatment Study (IATS). METHODS: Refractions were performed at 1 month and every 3 months postoperatively until age 4 years and then at ages 4.25, 4.5, and 5 years. The change in refraction over time was estimated by linear mixed model analysis. RESULTS: Intraocular lens implantation was completed in 56 eyes; 43 were analyzed (median age, 2.4 months; range, 1.0-6.8 months). Exclusions included 11 patients with glaucoma, 1 patient with Stickler syndrome, and 1 patient with an IOL exchange at 8 months postoperatively. The mean rate of change in a myopic direction from 1 month after cataract surgery to age 1.5 years was 0.35 diopters (D)/month (95% confidence interval [CI], 0.29-0.40 D/month); after age 1.5 years, the mean rate of change in a myopic direction was 0.97 D/year (95% CI, 0.66-1.28 D/year). The mean refractive change was 8.97 D (95% CI, 7.25-10.68 D) at age 5 years for children 1 month of age at surgery and 7.22 D (95% CI, 5.54-8.91 D) for children 6 months of age at surgery. The mean refractive error at age 5 years was -2.53 D (95% CI, -4.05 to -1.02). CONCLUSIONS: After IOL implantation during infancy, the rate of myopic shift occurs most rapidly during the first 1.5 years of life. Myopic shift varies substantially among patients. If the goal is emmetropia at age 5 years, then the immediate postoperative hypermetropic targets should be +10.5 D at 4 to 6 weeks and +8.50 D from 7 weeks to 6 months. However, even using these targets, it is likely that many children will require additional refractive correction given the high variability of refractive outcomes.

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

PURPOSE: To report the longitudinal change in axial length (AL) from the time of unilateral cataract surgery at age 1 to 7 months to age 5 years, and to compare AL growth of operated eyes with that of fellow unoperated eyes. DESIGN: Comparative case series. PARTICIPANTS: Infants enrolled in the Infant Aphakia Treatment Study (IATS). METHODS: The AL at baseline and age 5 years and change in AL were analyzed relative to treated versus fellow eye, visual outcome, and treatment modality (contact lens [CL] vs. intraocular lens [IOL]). Eyes with glaucoma or glaucoma suspect were excluded from primary analysis but reported separately. MAIN OUTCOME MEASURES: The AL growth from preoperative to age 5 years. RESULTS: Seventy patients were eligible; however, AL data for both eyes were available for 64 patients at baseline and 69 patients at age 5 years. The AL was significantly different between treated and fellow eyes preoperatively (18.1 vs. 18.7 mm, P < 0.0001) and at the final follow-up (21.4 vs. 22.1 mm, P = 0.0004). The difference in AL growth between treated and fellow eyes was not significant (3.3 vs. 3.5 mm, P = 0.31). The change in AL in eyes was similar with both treatments (CL 3.2 mm and IOL 3.4 mm, P = 0.53) and did not correlate with visual outcomes (P = 0.85). Eyes receiving additional surgery to clear the visual axis opacification grew significantly more compared with eyes not receiving surgery to clear the visual axis (3.8 vs. 2.7 mm, P = 0.013). Patients with glaucoma showed significantly more eye growth (5.7 mm) than those without glaucoma (3.3 mm) and glaucoma suspects (4.3 mm). CONCLUSIONS: Eyes treated for monocular cataract in infancy have axial growth similar to that of fellow eyes, despite having a shorter AL at the time of surgery. The change in AL in eyes was similar with both treatments (CL and IOL), did not correlate with visual outcomes, and was higher in eyes receiving additional surgery to clear the visual axis or eyes diagnosed with glaucoma.

Dexamethasone intravitreal implant (Ozurdex) for the treatment of pediatric uveitis.

PURPOSE: To report our experience using Ozurdex (Allergan, Irvine, CA), a biodegradable intravitreal implant containing of 0.7 mg of dexamethasone approved for use in adults with noninfectious uveitis in adults, in the treatment of pediatric uveitis. METHODS: The medical records of consecutive patients with noninfectious posterior uveitis who were unresponsive to standard treatment and subsequently received the Ozurdex implant from March 2011 to March 2013 were retrospectively reviewed. RESULTS: A total of 14 eyes of 11 patients (mean age, 10.1 years; range 4-12) received 22 Ozurdex implants during the study period. Of the 11 patients, 7 had idiopathic intermediate or posterior uveitis, 1 had sympathetic ophthalmia, 2 had juvenile idiopathic arthritis, and 1 had sarcoidosis. All patients were uncontrolled with standard treatment, including topical or sub-Tenon's or systemic corticosteriods and/or immune-modulation. Visual acuity improved after Ozurdex implant in 5 of 8 patients (63%). Intraocular inflammation was controlled or improved after 17 of 22 of implants (12 eyes [77%]). The frequency of topical corticosteroids was decreased and/or discontinued after 18 of 22 implants (12 eyes [82%]). Complications included implant migration into the anterior chamber (4 aphakic eyes), increased intraocular pressure (5 eyes), and progression of a preexisting cataract (1 eye). The uveitis reoccurred in 57% of eyes at 4.3 months (2-7 months) after injection. CONCLUSIONS: The Ozurdex implant in combination with systemic immunomodulatory therapy resulted in improved visual acuity, control of intraocular inflammation, and a decrease in corticosteroid use. In the majority of eyes the uveitis reoccurred around 4 months after injection. The adverse events in our study are similar to those identified in adult studies.

Office probing for treatment of nasolacrimal duct obstruction in infants.

PURPOSE: To determine whether demographic or clinical factors are associated with the outcome of office-based nasolacrimal duct probing for the treatment of congenital nasolacrimal duct obstruction (NLDO). METHODS: In two multicenter prospective studies, 384 eyes of 304 children aged 6 to <15 months with NLDO underwent a nasolacrimal duct probing performed in the office using topical anesthesia. Treatment success, defined as no clinical signs of NLDO (epiphora, increased tear lake, or mucous discharge) and no reoperation, was assessed 1 month after probing in one study and 6 months after probing in the other study. Data from both studies were pooled to evaluate associations between baseline characteristics and treatment success. RESULTS: Office probing was successful in 75% of eyes overall (95% CI, 70%-80%). The procedure was less successful in eyes of children with bilateral NLDO compared with unilateral NLDO (63% vs 80%; relative risk = 0.78 [95% CI, 0.66-0.92]) and in eyes that had 2 or 3 clinical signs of NLDO compared with one (71% vs 83%; relative risk = 0.88 [95% CI, 0.81-0.96]). Treatment success did not appear to be related to age, specific clinical signs of NLDO, prior treatment, or research study. CONCLUSIONS: Performing nasolacrimal duct probing in the office successfully treats NLDO in the majority of cases in children aged 6 to <15 months. The success rate is lower with bilateral disease or when more than one clinical sign of NLDO is present.

Fixation instability in anisometropic children with reduced stereopsis.

BACKGROUND: Hyperopic anisometropia in children can be associated with abnormal stereoacuity and "microstrabismus," a small temporalward "flick" as each eye assumes fixation on cover testing. The prevailing hypothesis is that abnormal sensory experience leads to foveal suppression and, subsequently, secondary microstrabismus. This study investigated the hypothesis that disruption of bifoveal fusion by anisometropia directly affects ocular motor function. METHODS: A total of 94 children with hyperopic anisometropia (ages 5-13 years) were evaluated prospectively between June 2010 and December 2012 with the use of the Nidek MP-1 microperimeter. Fixation instability was quantified by the area of the bivariate contour ellipse that included 95% of fixation points during a 30-second test interval. Each eye movement waveform during the 30-second test interval also was examined with the use of custom software and classified as normal, fusion maldevelopment nystagmus (FMNS), or infantile nystagmus. Finally, the Randot Preschool Stereoacuity Test (Stereo Optical Company Inc, Chicago, IL) was administered. RESULTS: Stereoacuity was correlated with fixation instability (Spearman r = 0.50; 95% CI, 0.33-0.64); visual acuity was more weakly correlated (r = 0.28). All children with normal stereoacuity had stable fixation, children with subnormal stereoacuity had fixation instability, and those with nil stereoacuity had the most instability. Eye movement records during attempted fixation were of sufficient quality for classification in 81 children; 61% of those with reduced stereoacuity and 88% of those with nil stereoacuity had FMNS eye movement waveforms. CONCLUSIONS: Our data support the hypothesis that the binocular decorrelation caused by anisometropia can disrupt ocular motor development, resulting in FMNS and its temporalward refoveating "flicks" that may mimic microstrabismus.

Intraocular pressure in pediatric patients during prone surgery.

BACKGROUND: Intraoperative intraocular pressure (IOP) in the prone position and IOP changes over time have not been evaluated in pediatric surgical patients. We sought to determine time-dependent changes in IOP in children undergoing surgery in prone position. METHODS: Thirty patients undergoing neurosurgical procedures in prone position were included. Using a pulse-mode pneumatonometer, IOP was measured in supine position after induction and before emergence of anesthesia and in prone position before the start and after the end of surgery. IOP changes over time in the prone position were assessed with a linear mixed model (i.e., random slope and intercept model) to adjust for the within-patient correlation. RESULTS: IOP in prone position increased by an average of 2.2 mm Hg per hour (P < 0.001). Sixty-three percent of patients (95% confidence interval [CI], 46%-81%) had at least 1 IOP value exceeding 30 mm Hg, and 13% (95% CI, 1%-25%) had at least 1 IOP value exceeding 40 mm Hg while prone. Mean IOP increased 7 mm Hg (95% CI, 6-9) during the position change from supine to prone (P < 0.001) and decreased 10 mm Hg (95% CI, 9-12) after changing the position from prone back to supine (P < 0.001). CONCLUSIONS: Changing position from supine to prone significantly increases IOP in anesthetized pediatric patients. Moreover, the IOP continued to increase during surgery and reached potentially harmful values, especially when combined with low mean arterial blood pressures that are common during major surgery.

Surgical results after one-muscle recession for correction of horizontal sensory strabismus in children.

PURPOSE: To report the success rates in children after one-muscle recession for sensory strabismus. METHODS: The medical records of consecutive patients ≤18 years of age who underwent primary unilateral horizontal surgery for sensory strabismus measuring ≤30(Δ) from 2004 to 2010 were retrospectively reviewed. Data collected included age at surgery, sex, length of follow-up, procedure performed, pre- and postoperative deviation, and treatment of associated vertical strabismus. Success was defined as a final deviation within 10(Δ) of orthotropia. RESULTS: A total of 33 patients (16 males) were included. Mean age at surgery was 5.2 years (range, 6 months to 17 years) and mean follow-up was 36 months (range, 6 months-7.4 years). Age at surgery (P = 0.37) and follow-up (P = 0.79) were comparable in patients with esotropia (n = 12) and exotropia (n = 21). Mean preoperative deviation was 23.7(Δ) in the esotropia group and 24(Δ) in the exotropia group (P = 0.875). Successful postoperative alignment was achieved in 76% of esotropic patients and 92% of exotropic patients (P = 0.379). Lateral rectus recessions resulted in a mean correction of 2.8(Δ)/mm of recession compared to 3.0(Δ)/mm for medial rectus recessions (P = 0.71). CONCLUSIONS: Advantages of one-muscle recession include a high success rate, few over-corrections, relatively short duration of surgery, and an intact muscle should reoperation be indicated.

Predictability of intraocular lens calculation and early refractive status: the Infant Aphakia Treatment Study.

OBJECTIVE: To report the accuracy of intraocular lens (IOL) power calculations and the early refractive status in pseudophakic eyes of infants in the Infant Aphakia Treatment Study. METHODS: Eyes randomized to receive primary IOL implantation were targeted for a postoperative refraction of +8.0 diopters (D) for infants 28 to 48 days old at surgery and +6.0 D for those 49 days or older to younger than 7 months at surgery using the Holladay 1 formula. Refraction 1 month after surgery was converted to spherical equivalent, and prediction error (PE; defined as the calculated refraction minus the actual refraction) and absolute PE were calculated. Baseline eye and surgery characteristics and A-scan quality were analyzed to compare their effect on PE. MAIN OUTCOME MEASURES: Prediction error. RESULTS: Fifty-six eyes underwent primary IOL implantation; 7 were excluded for lack of postoperative refraction (n = 5) or incorrect technique in refraction (n = 1) or biometry (n = 1). Overall mean (SD) absolute PE was 1.8 (1.3) D and mean (SD) PE was +1.0 (2.0) D. Absolute PE was less than 1 D in 41% of eyes but greater than 2 D in 41% of eyes. Mean IOL power implanted was 29.9 D (range, 11.5-40.0 D); most eyes (88%) implanted with an IOL of 30.0 D or greater had less postoperative hyperopia than planned. Multivariate analysis revealed that only short axial length (<18 mm) was significant for higher PE. CONCLUSIONS: Short axial length correlates with higher PE after IOL placement in infants. Less hyperopia than anticipated occurs with axial lengths of less than 18 mm or high-power IOLs. Application to Clinical Practice Quality A-scans are essential and higher PE is common, with a tendency for less hyperopia than expected. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00212134.

Trends in surgical correction of strabismus: a 20-year experience, 1990-2009.

BACKGROUND: Recent reports and anecdotal observations suggest that strabismus surgery, particularly for infantile esotropia, may be in decline, although a recent population-based study found the incidence to be stable. METHODS: We analyzed the surgical database of 4,494 primary pediatric strabismus procedures from 1990 through 2009 at Children's Medical Center of Dallas. Linear regression models were used to identify the relationship between the year and the proportion of each surgical category (infantile esotropia, all esotropia, exotropia, and other) using the least-squares approach. RESULTS: Surgery for infantile esotropia (mean age, 10 months) was performed on 374 patients (mean, 19; range, 11-27/year). Trend analysis demonstrated no significant change in the annual rate of surgery for infantile esotropia (R(2) = 0.004) during the 20-year study period. Additionally, when compared to the annual number of births in Dallas County, no significant change in the incidence of surgically corrected infantile esotropia was noted during the study period (P = 0.25); however, surgery for both infantile esotropia (P = 0.001) and for any esotropia (P = 0.002) declined, while surgery for exotropia increased (P = 0.002) as a proportion of all primary strabismus surgeries. CONCLUSIONS: The incidence of surgically corrected infantile esotropia has remained stable over a 20-year period. As a proportion of all primary strabismus procedures, surgery for all types of esotropia has decreased and for exotropia has increased.

Glaucoma following infantile cataract surgery.

PURPOSE: To examine incidence, risk factors, and outcomes of glaucoma following infantile cataract extraction. METHODS: A retrospective chart review of all patients who underwent cataract extraction between January 1, 1993, and December 31, 2006, at the Children's Medical Center in Dallas. RESULTS: Sixty-four eyes met inclusion criteria, of which 11 eyes (17.2%) developed glaucoma during a mean follow-up of 65.1 ± 4.3 months. Age younger than 3 months at cataract diagnosis (odds ratio 4.89, P = .05) or cataract extraction (odds ratio 4.4, P = .047) and the presence of anterior chamber anomalies (odds ratio 8.0, P = .01) were the only risk factors found to have statistical significance for the development of glaucoma. Eight of 11 eyes with glaucoma (72.2%) required at least one surgical intervention. Three of 10 eyes (30%) had a final best-corrected visual acuity below 20/400 and another 4 eyes (40%) demonstrated some degree of amblyopia. CONCLUSION: Despite modern microsurgical techniques, infantile cataract surgery continues to pose a risk of secondary glaucoma. This was particularly true when cataract was diagnosed and/or extracted in patients younger than 3 months of age. Most eyes that developed glaucoma required surgical management and visual outcomes continue to be poor in this group.

Treatment of severe amblyopia with weekend atropine: results from 2 randomized clinical trials.

PURPOSE: To determine the effectiveness of weekend atropine for severe amblyopia from strabismus, anisometropia, or both combined among children 3 to 12 years of age. METHODS: We enrolled children into 2 prospective, randomized multicenter clinical trials of amblyopia therapy. Herein we report the results for severe amblyopia, 20/125 to 20/400. In Trial 1, 60 children 3 to 6 years of age (mean, 4.4 years) were randomized to weekend atropine plus a plano lens or weekend atropine plus full spectacle correction for the sound eye. In Trial 2, 40 children 7 to 12 years of age (mean, 9.3 years) were randomized to weekend atropine or 2 hours of daily patching. The visual acuity outcome was assessed at 18 weeks in Trial 1 and 17 weeks in Trial 2. RESULTS: In Trial 1, visual acuity improved by an average of 4.5 lines in the atropine plus correction group (95% CI, 3.2-5.8 lines) and 5.1 lines in the atropine plus plano lens group (95% CI, 3.7-6.4 lines). In Trial 2, visual acuity improved by an average of 1.5 lines in the atropine group (95% CI, 0.5-2.5 lines) and 1.8 lines in the patching group (95% CI, 1.1-2.6 lines). CONCLUSIONS: Weekend atropine can improve visual acuity in children 3 to 12 years of age with severe amblyopia. Improvement may be greater in younger children.

The critical period for surgical treatment of dense congenital bilateral cataracts.

INTRODUCTION: We examined the critical period for deprivation amblyopia in a cohort of patients with dense bilateral congenital cataracts to investigate the optimum timing for surgical treatment. METHODS: Thirty-seven infants with dense bilateral congenital cataracts that were extracted by 31 weeks of age were enrolled prospectively. Visual acuity outcome was assessed at >/=5 years of age. We statistically evaluated which of 4 models provided the best fit to the data: (1) no change in visual acuity outcome with delay in surgery, (2) linear decline of outcome with delay, (3) a bilinear model in which a critical age exists after which outcome depends on delay, and (4) a bilinear model in which a critical age exists before which outcome depends on delay. In addition, we reviewed medical records for associated adverse outcomes, including strabismus, nystagmus, secondary membrane formation, and glaucoma. RESULTS: A bilinear model with a critical age of 14 weeks fit the data better than a linear model (chi(2) = 14.7; p < 0.0006). During weeks 0-14, mean visual acuity decreased by 1 line with each 3 weeks' delay in surgery. From 14 to 31 weeks, visual acuity was independent the subject's age at surgery, averaging 20/80. Surgery after 4 weeks was associated with a greater prevalence of strabismus and nystagmus than surgery before 4 weeks, whereas surgery during the first 4 weeks was associated with a greater prevalence of secondary membrane formation and glaucoma. CONCLUSIONS: We did not find a latent period for the treatment of children with dense bilateral congenital cataracts. Deprivation amblyopia may be minimized with early surgery for bilateral cataracts.