Eight-Year Outcomes of Bilateral Lateral Rectus Recessions versus Unilateral Recession-Resection in Childhood Basic-Type Intermittent Exotropia.

PURPOSE: To report 8-year outcomes from a randomized controlled trial (RCT) comparing bilateral lateral rectus muscle recession (BLRc) with unilateral recession-resection (R&R) for childhood intermittent exotropia (IXT). DESIGN: Eight-year follow-up of RCT cohort. PARTICIPANTS: Of 197 randomized participants, 123 agreed to continue follow-up after the 3-year outcome visit (baseline age, 3-< 11 years; basic-type IXT, 15-40 prism diopters [Δ] by prism and alternate cover test [PACT]; baseline stereoacuity, ≤ 400 arcsec; no prior surgery). METHODS: After the RCT primary outcome at 3 years, annual follow-up from 4 through 8 years with treatment at investigator discretion. MAIN OUTCOME MEASURES: Suboptimal surgical outcome by 8 years after randomization, defined as any of the following at any visit: exotropia of 10 Δ or more by simultaneous prism cover test (SPCT) at distance or near, constant esotropia (ET) of 6 Δ or more by SPCT at distance or near, loss of near stereoacuity by 0.6 log arcsec or more from baseline, or reoperation. Secondary outcomes included (1) reoperation by 8 years and (2) complete or near-complete resolution at 8 years, defined as exodeviation of less than 10 Δ by SPCT and PACT at distance and near and 10 Δ or more reduction from baseline by PACT at distance and near, ET of less than 6 Δ at distance and near, no decrease in stereoacuity by 0.6 log arcsec or more from baseline, and no reoperation or nonsurgical treatment for IXT. RESULTS: The Kaplan-Meier cumulative probability of suboptimal surgical outcome through 8 years was 68% (55 events among 101 at risk) for BLRc and 53% (42 events among 96 at risk) for R&R (difference, 15%; 95% confidence interval [CI], -2% to 32%; P = 0.08). Complete or near-complete resolution at 8 years occurred in 15% (7/46) for BLRc and 37% (16/43) for R&R (difference, -22%; 95% CI, -44% to -0.1%; P = 0.049). The cumulative probability of reoperation was 30% for BLRc and 11% for R&R (difference, 19%; 95% CI, 2%-36%; P = 0.049). CONCLUSIONS: Despite no significant difference for the primary outcome, the 95% CI did not exclude a moderate benefit of R&R, which together with secondary outcomes suggests that unilateral R&R followed by usual care may yield better long-term outcomes than BLRc followed by usual care for basic-type childhood IXT using these surgical doses. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Complications, Visual Acuity, and Refractive Error Three Years After Secondary Intraocular Lens implantation for Pediatric Aphakia.

OBJECTIVE: To report the cumulative incidence of complications and describe refractive error and visual acuity (VA) outcomes in children undergoing secondary intraocular lens (IOL) implantation following previous surgery for non-traumatic cataract. DESIGN: Pediatric cataract registry. PARTICIPANTS: 80 children (108 eyes: 60 bilateral, 48 unilateral) undergoing lensectomy at <13 years of age, followed by secondary IOL implantation at median age (range) of 2.7 (0.6 to 5.0) years for bilateral and 2.1 (0.5 to 6.4) for unilateral cases. METHODS: Annual data collection from medical record review through 5 years following lensectomy. MAIN OUTCOME MEASURES: Cumulative incidence of newly emergent complications following secondary IOL implantation; refractive error and VA by 5 years after lensectomy. RESULTS: Median (interquartile range [IQR]) follow-up following secondary IOL implantation was 2.5 years (0.8 to 3.3 years). A common complication following secondary IOL implantation was a glaucoma-related adverse event (GRAE: glaucoma or glaucoma suspect); the cumulative incidence was 17% (95% CI: 3%-29%) in bilateral and 12% (95% CI: 0%-23%) in unilateral cases. The cumulative incidence of surgery for visual axis opacification was 2% (95% CI: 0%-7%) for bilateral and 4% (95% CI: 0%-10%) for unilateral cases. Median prediction error (IQR) within 90 days of implantation was 0.88 D (-0.50 D to +3.00 D) less hyperopic than intended among 21 eyes for bilateral cases and 1.50 D (-0.25 D to +2.38 D) less among 19 unilateral cases. Median (IQR) spherical equivalent refractive error at 5 years (median 5.1 years of age) in eyes receiving a secondary IOL was +0.50 D (-2.38 D to +2.94 D) for 48 bilateral and +0.06 D (-2.25 D to +0.75 D) for 22 unilateral cases. Median (IQR) monocular VA at 5 years was 20/63 (20/50-20/100) for bilateral (n=42) and 20/400 (20/160-20/800) for unilateral (n=33) cases. CONCLUSIONS: Eyes with secondary IOL implantation have an ongoing risk of new glaucoma-related adverse events. Five years after lensectomy (approximately 2.5 years after secondary IOL implantation), average refractive error was less hyperopic than desired given the anticipated further myopic shift before refraction stabilizes.

A Pilot Randomized Clinical Trial of Base-in Relieving Prism Spectacle Treatment of Intermittent Exotropia.

SIGNIFICANCE: This pilot randomized trial, the first to evaluate a specific base-in relieving prism treatment strategy for childhood intermittent exotropia, did not support proceeding to a full-scale clinical trial. Defining and measuring prism adaptation in children with intermittent exotropia are challenging and need further study. PURPOSE: This study aimed to determine whether to proceed to a full-scale trial of relieving base-in prism spectacles versus refractive correction alone for children with intermittent exotropia. METHODS: Children 3 years old to those younger than 13 years with distance intermittent exotropia control score of ≥2 points on the Intermittent Exotropia Office Control Scale (Strabismus 2006;14:147-150; 0 [phoria] to 5 [constant]), ≥1 episode of spontaneous exotropia, and 16 to 35∆ by prism-and-alternate-cover test, who did not fully prism adapt on a 30-minute in-office prism-adaptation test were randomized to base-in relieving prism (40% of the larger of distance and near exodeviations) or nonprism spectacles for 8 weeks. A priori criteria to conduct a full-scale trial were defined for the adjusted treatment group difference in mean distance control: "proceed" (≥0.75 points favoring prism), "uncertain" (>0 to <0.75 points favoring prism), or "do not proceed" (≥0 points favoring nonprism). RESULTS: Fifty-seven children (mean age, 6.6 ± 2.2 years; mean baseline distance control, 3.5 points) received prism (n = 28) or nonprism (n = 29) spectacles. At 8 weeks, mean control values were 3.6 and 3.3 points in prism (n = 25) and nonprism (n = 25) groups, respectively, with an adjusted difference of 0.3 points (95% confidence interval, -0.5 to 1.1 points) favoring nonprism (meeting our a priori "do not proceed" criterion). CONCLUSIONS: Base-in prism spectacles, equal to 40% of the larger of the exodeviations at distance or near, worn for 8 weeks by 3- to 12-year-old children with intermittent exotropia did not yield better distance control than refractive correction alone, with the confidence interval indicating that a favorable effect of 0.75 points or larger is unlikely. There was insufficient evidence to warrant a full-scale randomized trial.

Vascular Risk Factors in Isolated Microvascular Ischemic Third Nerve Palsy: A Population-Based Study.

BACKGROUND: Although presumed microvascular third nerve palsies (TNP) have been associated with vascular risk factors and/or stroke, these associations have not been explored in a population-based cohort. The purpose of this population-based case-control study was to determine whether these factors are associated with TNPs that had been classified as isolated microvascular ischemic events and determine future risk of mortality. METHODS: Participants were subjects >18 years old with new onset of isolated TNP attributed to presumed microvascular ischemia (n = 55) while residing in Olmsted County, Minnesota, from January 1, 1978 to December 31, 2014. Control subjects (n = 55) were randomly selected from the same population and matched for gender, age, and length of medical follow-up. We identified all cases of new-onset isolated presumed microvascular ischemic TNP using the Rochester Epidemiology Project, a record-linkage system of medical records for all patient-physician encounters in Olmsted County, Minnesota. All medical records of cases and controls were reviewed for potential risk factors, including diabetes mellitus, diabetic retinopathy, hypertension, hyperlipidemia, smoking, and symptomatic ischemic stroke. Multivariable and univariate logistic regression analyses were used to compare the prevalence of potential risk factors between microvascular ischemic cases and controls according to the number of subjects, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Kaplan-Meier curves were used to compare mortality between cases and controls. RESULTS: The annual incidence of microvascular ischemic TNP was 1.7 per 100,000. Univariate analysis demonstrated that hypertension ( P < 0.001; OR, 4.80; 95% CI, 2.11-11.58), diabetes mellitus ( P < 0.001; OR, 6.55; 95% CI, 2.72-17.32), diabetic retinopathy ( P = 0.014; OR, 13.50; 95% CI, 2.48-251.55), coronary artery disease ( P = 0.047; OR, 2.27; 95% CI, 1.02-5.18), and symptomatic ischemic stroke ( P = 0.039; OR, 3.56; 95% CI, 1.07-11.85) all occurred more frequently in patients with microvascular ischemic TNP than controls. In multivariate analysis, only hypertension (OR of 4.14, 95% CI, 1.61-10.65, P < 0.001) and diabetes (OR of 4.12, 95% CI, 1.43-11.92, P = 0.003) remained independently statistically significant. There was numerically higher mortality in microvascular cases than in controls, but it did not reach statistical significance. CONCLUSIONS: There are multiple cardiovascular diseases that are associated with isolated microvascular ischemic TNP, including hypertension, coronary artery disease, diabetes mellitus, diabetic retinopathy, and symptomatic ischemic stroke. Given that the main drivers of this association seem to be diabetes and hypertension, patients with microvascular ischemic TNP should be evaluated for these conditions.

Low- and Very Low-Dose Bevacizumab for Retinopathy of Prematurity: Reactivations, Additional Treatments, and 12-Month Outcomes.

PURPOSE: Low-dose and very low-dose intravitreal bevacizumab (IVB) have been reported to be successful in short-term treatment of type 1 retinopathy of prematurity (ROP), down to an initial dose of 0.004 mg. We now report 12-month outcomes for these infants. DESIGN: Masked, multicenter, dose de-escalation study. PARTICIPANTS: One hundred twenty prematurely born infants with type 1 ROP. METHODS: A cohort of 120 infants with type 1 ROP in at least 1 eye from 2 sequential dose de-escalation studies of low-dose IVB (0.25 mg, 0.125 mg, 0.063 mg, and 0.031 mg) or very low-dose IVB (0.016 mg, 0.008 mg, 0.004 mg, and 0.002 mg) to the study eye; the fellow eye (if also type 1) received 1 dose level higher of IVB. After primary success or failure at 4 weeks, clinical management was at investigator discretion, including all additional treatment. MAIN OUTCOME MEASURES: Reactivation of severe ROP by 6 months corrected age, additional treatments, retinal and other ocular structural outcomes, and refractive error at 12 months corrected age. RESULTS: Sixty-two of 113 study eyes (55%) and 55 of 98 fellow eyes (56%) received additional treatment. Of the study eyes, 31 (27%) received additional ROP treatment, and 31 (27%) received prophylactic laser therapy for persistent avascular retina. No trend toward a higher risk of additional ROP treatment related to initial IVB doses was found. However, time to reactivation among study eyes was shorter in eyes that received very low-dose IVB (mean, 76.4 days) than in those that received low-dose IVB (mean, 85.7 days). At 12 months, poor retinal outcomes and anterior segment abnormalities both were uncommon (3% and 5%, respectively), optic atrophy was noted in 10%, median refraction was mildly myopic (-0.31 diopter), and strabismus was present in 29% of infants. CONCLUSIONS: Retinal structural outcomes were very good after low- and very low-dose IVB as initial treatment for type 1 ROP, although many eyes received additional treatment. The rate of reactivation of severe ROP was not associated with dose; however, a post hoc data-driven analysis suggested that reactivation was sooner with very low doses.

The Pediatric Optic Neuritis Prospective Outcomes Study: Two-Year Results.

PURPOSE: Pediatric optic neuritis (ON) is a rare disease that has not been well characterized. The Pediatric ON Prospective Outcomes Study (PON1) was the first prospective study to our knowledge aiming to evaluate visual acuity (VA) outcomes, including VA, recurrence risk, and final diagnosis 2 years after enrollment. DESIGN: Nonrandomized observational study at 23 pediatric ophthalmology or neuro-ophthalmology clinics in the United States and Canada. PARTICIPANTS: A total of 28 (64%) of 44 children initially enrolled in PON1 (age 3-<16 years) who completed their 2-year study visit. METHODS: Participants were treated at the investigator's discretion. MAIN OUTCOMES MEASURES: Age-normal monocular high-contrast VA (HCVA). Secondary outcomes included low-contrast VA (LCVA), neuroimaging findings, and final diagnoses. RESULTS: A total of 28 participants completed the 2-year outcome with a median enrollment age of 10.3 years (range, 5-15); 46% were female, and 68% had unilateral ON at presentation. Final 2-year diagnoses included isolated ON (n = 11, 39%), myelin oligodendrocyte glycoprotein-associated demyelination (n = 8, 29%), multiple sclerosis (MS) (n = 4,14%), neuromyelitis optica spectrum disease (NMOSD) (n = 3, 11%), and acute disseminated encephalomyelitis (n = 2, 7%). Two participants (7%; 95% confidence interval [CI], 1-24) had subsequent recurrent ON (plus 1 participant who did not complete the 2-year visit); all had MS. Two other participants (7%) had a new episode in their unaffected eye. Mean presenting HCVA was 0.81 logarithm of the minimum angle of resolution (logMAR) (∼20/125), improving to 0.14 logMAR (∼20/25-2) at 6 months, 0.12 logMAR (∼20/25-2) at 1 year, and 0.11 logMAR (20/25-1) at 2 years (95% CI, -0.08 to 0.3 [20/20+1-20/40-1]). Twenty-four participants (79%) had age-normal VA at 2 years (95% CI, 60-90); 21 participants (66%) had 20/20 vision or better. The 6 participants without age-normal VA had 2-year diagnoses of NMOSD (n = 2 participants, 3 eyes), MS (n = 2 participants, 2 eyes), and isolated ON (n = 2 participants, 3 eyes). Mean presenting LCVA was 1.45 logMAR (∼20/500-2), improving to 0.78 logMAR (∼20/125+2) at 6 months, 0.69 logMAR (∼20/100+1) at 1 year, and 0.68 logMAR (∼20/100+2) at 2 years (95% CI, 0.48-0.88 [20/50+1-20/150-1]). CONCLUSIONS: Despite poor VA at presentation, most children had marked improvement in VA by 6 months that was maintained over 2 years. Associated neurologic autoimmune diagnoses were common. Additional episodes of ON occurred in 5 (18%) of the participants (3 relapses and 2 new episodes).

On the importance of integrating comparative anatomy and One Health perspectives in anatomy education.

As a result of many factors, including climate change, unrestricted population growth, widespread deforestation and intensive agriculture, a new pattern of diseases in humans is emerging. With increasing encroachment by human societies into wild domains, the interfaces between human and animal ecosystems are gradually eroding. Such changes have led to zoonoses, vector-borne diseases, infectious diseases and, most importantly, the emergence of antimicrobial-resistant microbial strains as challenges for human health. Now would seem to be an opportune time to revisit old concepts of health and redefine some of these in the light of emerging challenges. The One Health concept addresses some of the demands of modern medical education by providing a holistic approach to explaining diseases that result from a complex set of interactions between humans, environment and animals, rather than just an amalgamation of isolated signs and symptoms. An added advantage is that the scope of One Health concepts has now expanded to include genetic diseases due to advancements in omics technology. Inspired by such ideas, a symposium was organised as part of the 19th International Federation of Associations of Anatomists (IFAA) Congress (August 2019) to investigate the scope of One Health concepts and comparative anatomy in contemporary medical education. Speakers with expertise in both human and veterinary anatomy participated in the symposium and provided examples where these two disciplines, which have so far evolved largely independent of each other, can collaborate for mutual benefit. Finally, the speakers identified some key concepts of One Health that should be prioritised and discussed the diverse opportunities available to integrate these priorities into a broader perspective that would attempt to explain and manage diseases within the scopes of human and veterinary medicine.

A Randomized Trial of Binocular Dig Rush Game Treatment for Amblyopia in Children Aged 4 to 6 Years.

SIGNIFICANCE: Binocular treatment for unilateral amblyopia is an emerging treatment that requires evaluation through a randomized clinical trial. PURPOSE: This study aimed to compare change in amblyopic-eye visual acuity (VA) in children aged 4 to 6 years treated with the dichoptic binocular iPad (Apple, Cupertino, CA) game, Dig Rush (not yet commercially available; Ubisoft, Montreal, Canada), plus continued spectacle correction versus continued spectacle correction alone. METHODS: Children (mean age, 5.7 years) were randomly assigned to home treatment for 8 weeks with the iPad game (prescribed 1 h/d, 5 d/wk [n = 92], or continued spectacle correction alone [n = 90]) in a multicenter randomized clinical trial. Before enrollment, children wearing spectacles were required to have at least 16 weeks of wear or no improvement in amblyopic-eye VA (<0.1 logMAR) for at least 8 weeks. Outcome was change in amblyopic-eye VA from baseline to 4 weeks (primary) and 8 weeks (secondary) assessed by masked examiner. RESULTS: A total of 182 children with anisometropic (63%), strabismic (16%; <5∆ near, simultaneous prism and cover test), or combined-mechanism (20%) amblyopia (20/40 to 20/200; mean, 20/63) were enrolled. After 4 weeks, mean amblyopic VA improved by 1.1 logMAR lines with binocular treatment and 0.6 logMAR lines with spectacles alone (adjusted difference, 0.5 lines; 95.1% confidence interval [CI], 0.1 to 0.9). After 8 weeks, results (binocular treatment: mean amblyopic-eye VA improvement, 1.3 vs. 1.0 logMAR lines with spectacles alone; adjusted difference, 0.3 lines; 98.4% CI, -0.2 to 0.8 lines) were inconclusive because the CI included both zero and the pre-defined difference in mean VA change of 0.75 logMAR lines. CONCLUSIONS: In 4- to 6-year-old children with amblyopia, binocular Dig Rush treatment resulted in greater improvement in amblyopic-eye VA for 4 weeks but not 8 weeks. Future work is required to determine if modifications to the contrast increment algorithm or other aspects of the game or its implementation could enhance the treatment effect.

Rasch-calibrated Intermittent Exotropia Symptom Questionnaire for Children.

SIGNIFICANCE: A rigorously designed and calibrated symptom questionnaire for childhood intermittent exotropia would be useful for clinical care and for research. PURPOSE: The aim of this study was to Rasch-calibrate and evaluate the previously developed Child Intermittent Exotropia Symptom Questionnaire using data gathered as part of a randomized clinical trial. METHODS: The questionnaire was administered to 386 children aged 3 to 10 years with intermittent exotropia who were enrolled in a randomized clinical trial comparing overminus with nonoverminus spectacles. Participants were followed at 6 and 12 months while on treatment and at 18 months off treatment. Factor analysis determined dimensionality, and Rasch analysis evaluated questionnaire performance. Logit values were converted to 0 (best) to 100 (worst). We evaluated differences in questionnaire scores between treatment groups and time points, and correlations with control scores. RESULTS: The Child Intermittent Exotropia Symptom Questionnaire was unidimensional. Rasch analysis indicated that there was no notable local dependence and no significant differential item functioning for sex or age. There was suboptimal targeting (mean logit, -1.62), and person separation was somewhat poor (0.95). There were no significant differences in the Child Intermittent Exotropia Symptom score between overminus spectacles and nonoverminus spectacles at 6, 12, and 18 months. Combining data from both treatment groups, there was significant improvement from baseline at all follow-up visits (e.g., mean change from baseline to 12 months, -6.6 points; 95% confidence interval, -8.6 to -4.6). Child Intermittent Exotropia Symptom scores were not correlated with distance or near control scores at 12 months. CONCLUSIONS: The seven-item Rasch-scored Child Intermittent Exotropia Symptom Questionnaire is limited by suboptimal performance. Future study is needed to determine whether it may be useful for clinical practice and for research.

Relationships among Clinical Factors and Patient-reported Outcome Measures in Adults with Convergence Insufficiency.

SIGNIFICANCE: When exploring relationships among clinical measures and patient-reported outcome measures in adults with convergence insufficiency, worse symptoms (Convergence Insufficiency Symptom Survey [CISS] score) seemed to be correlated with worse reading function domain score (Adult Strabismus-20 quality-of-life questionnaire). After treatment, improved symptoms were associated with improved reading function quality of life. PURPOSE: This study aimed to explore relationships between clinical measures and patient-reported outcome measures in adults undergoing treatment for symptomatic convergence insufficiency. METHODS: In a prospective multicenter observational study, we evaluated adults with symptomatic convergence insufficiency (i.e., clinical measures of near exodeviation, receded near point of convergence, reduced near positive fusional vergence; CISS score ≥21). Fifty-seven participants treated with vision therapy/exercises (n = 35) or base-in prism (n = 22) were analyzed. Spearman correlation coefficients ( R ) were used to assess associations among the three clinical measures and patient-reported outcome measures (CISS, Diplopia Questionnaire, four Adult Strabismus-20 quality-of-life domains) before treatment (baseline) and after 10 weeks and 1 year. Associations were interpreted to be present when the lower limit of the 95% confidence interval (CI) was moderate to strong ( R ≥ 0.4). RESULTS: Among multiple exploratory analyses, the only moderate to strong baseline correlation was between worse CISS and worse Adult Strabismus-20 reading function scores ( R = 0.62; 95% CI, 0.43 to 0.76). Regarding change in measures with treatment, the only moderate to strong correlations were between improved CISS and improved Adult Strabismus-20 reading function scores for prism at 10 weeks ( R = 0.78; 95% CI, 0.52 to 0.91) and 1 year ( R = 0.85; 95% CI, 0.65 to 0.94) and for vision therapy/exercises at 1 year ( R = 0.78; 95% CI, 0.57 to 0.89). CONCLUSIONS: In exploratory analyses, we found positive correlations between CISS symptom scores and reading function quality-of-life scores. The absence of correlations between symptoms and individual clinical measures is consistent with clinical experience that, in convergence insufficiency, symptoms and clinical findings can be discordant.

Three-year observation of children 12 to 35 months old with untreated intermittent exotropia.

PURPOSE: To describe the clinical course of untreated intermittent exotropia (IXT) in children 12-35 months of age followed for 3 years. METHODS: We enrolled 97 children 12-35 months of age with previously untreated IXT who had been randomly assigned to the observation arm of a randomised trial of short-term occlusion versus observation. Participants were observed unless deterioration criteria were met at a follow-up visit occurring at 3 months, 6 months, and 6-month intervals thereafter for 3 years. The primary outcome was deterioration of the IXT by 3 years, defined as (1) a constant exotropia ≥10 prism dioptres (∆) at distance and near (i.e., motor deterioration) or (2) treatment prescribed despite not having met motor deterioration. The primary analysis used the Kaplan-Meier method to determine the cumulative proportion of participants meeting deterioration by three years and 95% confidence interval (CI). RESULTS: The cumulative probability of deterioration by 3 years was 28% (95% CI = 20%-39%). Of the 24 participants meeting the primary outcome of deterioration, seven met motor deterioration and 17 were prescribed treatment without meeting motor deterioration. The cumulative probability of motor deterioration by 3 years was 10% (95% CI = 5%-19%). CONCLUSIONS: Given the modest rate of motor deterioration over three years, watchful waiting may be a reasonable management approach in 12- to 35-month-old children with IXT. To confirm this recommendation would require a long-term randomised trial of immediate treatment versus observation followed by deferred treatment if needed.

A Randomized Trial Comparing Bilateral Lateral Rectus Recession versus Unilateral Recess and Resect for Basic-Type Intermittent Exotropia.

PURPOSE: To compare long-term outcomes after bilateral lateral rectus recession (BLRc) or unilateral lateral rectus recession combined with medial rectus resection in the same eye (R&R) for primary treatment of childhood intermittent exotropia (IXT). DESIGN: Multicenter, randomized clinical trial. PARTICIPANTS: One hundred ninety-seven children 3 to younger than 11 years of age with basic-type IXT, a largest deviation by prism and alternate cover test at any distance of 15 to 40 prism diopters (PD), and near stereoacuity of at least 400 seconds of arc. METHODS: Random assignment to BLRc or R&R and masked examinations conducted every 6 months after surgery for 3 years. MAIN OUTCOME MEASURES: Proportion of participants meeting suboptimal surgical outcome by 3 years, defined as: (1) exotropia of 10 PD or more at distance or near using simultaneous prism and cover test (SPCT); or (2) constant esotropia of 6 PD or more at distance or near using SPCT; (3) loss of 2 octaves or more of stereoacuity from baseline, at any masked examination; or (4) reoperation without meeting any of these criteria. RESULTS: Cumulative probability of suboptimal surgical outcome by 3 years was 46% (43/101) in the BLRc group versus 37% (33/96) in the R&R group (treatment group difference of BLRc minus R&R, 9%; 95% confidence interval [CI], -6% to 23%). Reoperation by 3 years occurred in 9 participants (10%) in the BLRc group (8 of 9 met suboptimal surgical outcome criteria) and in 4 participants (5%) in the R&R group (3 of 4 met suboptimal surgical outcome criteria; treatment group difference of BLRc minus R&R, 5%; 95% CI, -2% to 13%). Among participants completing the 3-year visit, 29% (25 of 86) in the BLRc group and 17% (13 of 77) in the R&R group underwent reoperation or met suboptimal surgical outcome criteria at 3 years (treatment group difference of BLRc minus R&R, 12%; 95% CI, -1% to 25%). CONCLUSIONS: We did not find a statistically significant difference in suboptimal surgical outcome by 3 years between children with IXT treated with BLRc compared with those treated with R&R. Based on these findings, we are unable to recommend one surgical approach over the other for childhood IXT.

A Randomized Trial of Binocular Dig Rush Game Treatment for Amblyopia in Children Aged 7 to 12 Years.

PURPOSE: To compare visual acuity (VA) improvement in children aged 7 to 12 years with amblyopia treated with a binocular iPad game plus continued spectacle correction vs. continued spectacle correction alone. DESIGN: Multicenter randomized clinical trial. PARTICIPANTS: One hundred thirty-eight participants aged 7 to 12 years with amblyopia (33-72 letters, i.e., approximately 20/200 to 20/40) resulting from strabismus, anisometropia, or both. Participants were required to have at least 16 weeks of optical treatment in spectacles if needed or demonstrate no improvement in amblyopic-eye visual acuity (VA) for at least 8 weeks prior to enrollment. METHODS: Eligible participants (mean age 9.6 years, mean baseline VA of 59.6 letters, history of prior amblyopia treatment other than spectacles in 96%) were randomly assigned to treatment for 8 weeks with the dichoptic binocular Dig Rush iPad game (prescribed for 1 hour per day 5 days per week) plus spectacle wear if needed (n = 69) or continued spectacle correction alone if needed (n = 69). MAIN OUTCOME MEASURES: Change in amblyopic-eye VA from baseline to 4 weeks, assessed by a masked examiner. RESULTS: At 4 weeks, mean amblyopic-eye VA letter score improved from baseline by 1.3 (2-sided 95% confidence interval [CI]: 0.1-2.6; 0.026 logMAR) with binocular treatment and by 1.7 (2-sided 95% CI: 0.4-3.0; 0.034 logMAR) with continued spectacle correction alone. After adjusment for baseline VA, the letter score difference between groups (binocular minus control) was -0.3 (95% CI: -2.2 to 1.5, P = 0.71, difference of -0.006 logMAR). No difference in letter scores was observed between groups when the analysis was repeated after 8 weeks of treatment (adjusted mean: -0.1, 98.3% CI: -2.4 to 2.1). For the binocular group, adherence data from the iPad indicated that slightly more than half of the participants (58% and 56%) completed >75% of prescribed treatment by the 4- and 8-week visits, respectively. CONCLUSIONS: In children aged 7 to 12 years who have received previous treatment for amblyopia other than spectacles, there was no benefit to VA or stereoacuity from 4 or 8 weeks of treatment with the dichoptic binocular Dig Rush iPad game.

Three-Year Observation of Children 3 to 10 Years of Age with Untreated Intermittent Exotropia.

PURPOSE: To describe the course of intermittent exotropia (IXT) in children followed up without treatment for 3 years. DESIGN: Observation arm from randomized trial of short-term occlusion versus observation. PARTICIPANTS: One hundred eighty-three children 3 to 10 years of age with previously untreated IXT and 400 seconds of arc (arcsec) or better near stereoacuity. METHODS: Participants were to receive no treatment unless deterioration criteria were met at a follow-up visit occurring at 3 months, 6 months, or 6-month intervals thereafter for 3 years. MAIN OUTCOME MEASURES: The primary outcome was deterioration by 3 years, defined as meeting motor criterion (constant exotropia ≥10 prism diopters [Δ] at distance and near) or near stereoacuity criterion (≥2-octave decrease from best previous measure). For the primary analysis, participants also were considered to have deteriorated if treatment was prescribed without meeting either deterioration criterion. RESULTS: The cumulative probability of protocol-specified deterioration by 3 years was 15% (95% confidence interval, 10%-22%), but that was likely an overestimate, partly because of misclassification. Among 25 deteriorations, 2 met motor deterioration, 11 met stereoacuity deterioration, and 12 started treatment without meeting either criteria (7 for social concern, 1 for diplopia, 4 for other reasons). Among the 132 participants who completed the 3-year visit and had not been treated during the study, only 1 (<1%) met motor or stereoacuity deterioration criteria at 3 years. Of the 4 participants completing the 3-year visit who met deterioration criteria previously and had not started treatment, none still met deterioration criteria. Between the baseline and 3-year examination for these 132 patients, improvement occurred in distance and near stereoacuity (mean improvement, 0.14 and 0.14 logarithm of arcsec; P ≤ 0.001 and P ≤ 0.001, respectively), distance exotropia control (mean improvement, 0.6 points; P ≤ 0.001), and distance exodeviation magnitude (mean improvement, 2.2 Δ; P = 0.002). CONCLUSIONS: Among children 3 to 10 years of age with IXT for whom surgery was not considered to be the immediately necessary treatment, stereoacuity deterioration or progression to constant exotropia over 3 years was uncommon, and exotropia control, stereoacuity, and magnitude of deviation remained stable or improved slightly.

A Randomized Clinical Trial of Immediate versus Delayed Glasses for Moderate Hyperopia in 1- and 2-Year-Olds.

PURPOSE: Two strategies were compared for managing moderate hyperopia without manifest strabismus among 1- and 2-year-old children: (1) immediate prescription of glasses versus (2) observation without glasses unless reduced distance visual acuity (VA), reduced stereoacuity, or manifest strabismus. DESIGN: Prospective randomized clinical trial. PARTICIPANTS: A total of 130 children aged 1 to 2 years with hyperopia between +3.00 diopters (D) and +6.00 D spherical equivalent (SE) in at least 1 eye, anisometropia ≤1.50 D SE, and astigmatism ≤1.50 D based on cycloplegic refraction and no manifest strabismus. METHODS: Participants were randomly assigned to glasses (1.00 D less than full cycloplegic hyperopia) versus observation and followed every 6 months for 3 years. Glasses were prescribed to those assigned to observation if they met prespecified deterioration criteria of distance VA or near stereoacuity below age norms, or development of manifest strabismus. MAIN OUTCOME MEASURES: At the 3-year primary outcome examination, participants were classified as failing the randomized management regimen if distance VA or stereoacuity was below age norms or manifest strabismus was observed (each with and without correction in trial frames, confirmed by masked retest, irrespective of whether deterioration had occurred previously), or if strabismus surgery had been performed. RESULTS: Of the 106 participants (82%) completing the 3-year primary outcome examination, failure occurred in 11 (21%) of 53 in the glasses group and 18 (34%) of 53 in the observation group (difference = -13%; 95% confidence interval [CI], -31 to 4; P = 0.14). Sixty-two percent (95% CI, 49-74) in the observation group and 34% (95% CI, 23-48) in the glasses group met deterioration criteria (requiring glasses if not wearing). CONCLUSIONS: For 1- and 2-year-olds with uncorrected moderate hyperopia (+3.00 D to +6.00 D SE), our estimates of failure, after 3 years of 6-month follow-ups, are inconclusive and consistent with a small to moderate benefit or no benefit of immediate prescription of glasses compared with careful observation (with glasses only if deteriorated).

Treatment of amblyopia as a function of age.

Although historically, treatment of amblyopia has been recommended prior to closure of a critical window in visual development, the existence and duration of that critical window is currently unclear. Moreover, there is clear evidence, both from animal and human studies of deprivation amblyopia, that there are different critical windows for different visual functions and that monocular and binocular deprivation have different neural and behavioral consequences. In view of the spectrum of critical windows for different visual functions and for different types of amblyopia, combined with individual variability in these windows, treatment of amblyopia has been increasingly offered to older children and adults. Nevertheless, treatment beyond the age of 7 years tends to be, on average, less effective than in younger children, and the high degree of variability in treatment response suggests that age is only one of many factors determining treatment response. Newly emerging treatment modalities may hold promise for more effective treatment of amblyopia at older ages. Additional studies are needed to characterize amblyopia by using new and existing clinical tests, leading to improved clinical classification and better prediction of treatment response. Attention also needs to be directed toward characterizing and measuring the impact of amblyopia on the patients' functional vision and health-related quality of life.

Intraoperative Findings in Consecutive Exotropia with and without Adduction Deficit.

PURPOSE: Consecutive exotropia may be associated with limited adduction, which has been reported to be caused by 1 or more anatomic abnormalities of rectus muscles or their insertions. We studied the relative frequency of grades of adduction deficit and the relative frequency of abnormal anatomic findings. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients undergoing surgery for consecutive exotropia. METHODS: Preoperative duction deficits were graded on a -5 (severe limitation) to 0 (normal) scale. Operative reports were reviewed to classify intraoperative factors: (1) medial rectus muscle attachment type (normal, abnormal [slipped or stretched scar], attached to pulley, behind pulley, or mixed [a tenuous normal attachment, but with muscle fibers also attached to the pulley or behind the pulley]), (2) medial rectus muscle distal fiber location (millimeters from original insertion), and (3) lateral rectus muscle tightness (normal, mild restriction, moderate restriction). MAIN OUTCOME MEASURES: Relationship of grade of adduction deficit to each intraoperative factor. RESULTS: Of 143 eyes, 124 (87%) had an adduction deficit. Eyes with abnormal (n = 23), pulley (n = 9), behind pulley (n = 8), or mixed (n = 7) attachments had worse adduction deficits than normal attachments (n = 96; P < 0.02). There was a significant correlation between distal medial rectus muscle fiber location (0-19.5 mm recessed) and grade of adduction deficit (P < 0.0001). Eyes with mild or moderate lateral rectus muscle tightness on forced duction testing (n = 48/143 eyes) had worse adduction deficits than eyes without tightness (P < 0.001). Nevertheless, despite overall correlation, there was considerable individual variability. For example, for -1 and -2 adduction deficits, medial rectus muscle attachment could be at the pulley, behind the pulley, or include the pulley (19/87 eyes [22%]), and the lateral rectus muscle was tight in 36 of 87 eyes (41%). CONCLUSIONS: Adduction deficits are common in patients with consecutive exotropia. Overall, more severe preoperative adduction deficits are associated with medial rectus muscle insertion abnormalities and abnormal forced ductions, but frequently there are exceptions. Severe medial rectus muscle insertion abnormalities, including lost muscles, may be found despite mild preoperative adduction deficits.

Diplopia in Medically and Surgically Treated Patients with Glaucoma.

PURPOSE: To report the prevalence, type, and cause of diplopia in medically and surgically treated patients with glaucoma. DESIGN: Cohort study. PARTICIPANTS: A total of 195 adult patients with glaucoma treated in a glaucoma referral practice. METHODS: A total of 195 adult patients with glaucoma who had undergone surgical or medical management were prospectively enrolled. Forty-seven patients had undergone glaucoma drainage device (GDD) surgery (Baerveldt 350, Baerveldt 250 [Abbott Medical Optics, Abbott Park, IL], or Ahmed FP7 [New World Medical Inc, Rancho Cucamonga, CA]), 61 patients had undergone trabeculectomy, and 87 patients were medically treated. All patients completed the Diplopia Questionnaire to assess diplopia. We defined the presence of diplopia as "sometimes," "often," or "always" in distance straight ahead or reading positions on the Diplopia Questionnaire. A chart review was performed jointly by a strabismus specialist and a glaucoma subspecialist to characterize the type and cause of the diplopia. MAIN OUTCOME MEASURES: Frequency, type, and cause of diplopia. RESULTS: Diplopia was reported in 41 of 195 medically and surgically treated patients (21%) with glaucoma. Binocular diplopia due to the glaucoma procedure was present in 11 of 47 patients (23%) after GDD (95% confidence interval, 12-38), which was significantly greater than in patients after trabeculectomy (2/61 [3%]; 95% confidence interval, 0.4-11; P = 0.002). The most common type of strabismus associated with binocular diplopia due to glaucoma surgery was hypertropia (10/11 GDD cases, 2/2 trabeculectomy cases). Monocular diplopia was found in a similar proportion of medically treated, post-trabeculectomy, and post-GDD cases (4/87 [5%], 4/61 [7%], and 2/47 [4%], respectively). Binocular diplopia not due to surgery was found in similar proportions of GDD, trabeculectomy, and medically treated cases (3/47 [6%], 5/61 [8%], and 10/87 [11%], respectively). CONCLUSIONS: Diplopia may be under-recognized in medically and surgically treated patients with glaucoma, and standardization of ascertaining patient symptoms using the Diplopia Questionnaire may be useful in these patients. Diplopia was more commonly seen after GDD than trabeculectomy, typically a noncomitant restrictive hypertropia. The prevalence of monocular diplopia and binocular diplopia unrelated to glaucoma surgery was similar among medical and surgical groups. It is important to counsel patients on the higher occurrence of diplopia associated with GDD surgery.

A Randomized Trial Evaluating Short-term Effectiveness of Overminus Lenses in Children 3 to 6 Years of Age with Intermittent Exotropia.

PURPOSE: To evaluate the short-term effectiveness of overminus spectacles in improving control of childhood intermittent exotropia (IXT). DESIGN: Randomized, clinical trial. PARTICIPANTS: A total of 58 children aged 3 to <7 years with IXT. Eligibility criteria included a distance control score of 2 or worse (mean of 3 measures during a single examination) on a scale of 0 (exophoria) to 5 (constant exotropia) and spherical equivalent refractive error between -6.00 diopters (D) and +1.00 D. METHODS: Children were randomly assigned to overminus spectacles (-2.50 D over cycloplegic refraction) or observation (non-overminus spectacles if needed or no spectacles) for 8 weeks. MAIN OUTCOME MEASURES: The primary outcome was distance control score for each child (mean of 3 measures during a single examination) assessed by a masked examiner at 8 weeks. Outcome testing was conducted with children wearing their study spectacles or plano spectacles for the children in the observation group who did not need spectacles. The primary analysis compared mean 8-week distance control score between treatment groups using an analysis of covariance model that adjusted for baseline distance control, baseline near control, prestudy spectacle wear, and prior IXT treatment. Treatment side effects were evaluated using questionnaires completed by parents. RESULTS: At 8 weeks, mean distance control was better in the 27 children treated with overminus spectacles than in the 31 children who were observed without treatment (2.0 vs. 2.8 points, adjusted difference = -0.75 points favoring the overminus group; 2-sided 95% confidence interval, -1.42 to -0.07 points). Side effects of headaches, eyestrain, avoidance of near activities, and blur appeared similar between treatment groups. CONCLUSIONS: In a pilot randomized clinical trial, overminus spectacles improved distance control at 8 weeks in children aged 3 to <7 years with IXT. A larger and longer randomized trial is warranted to assess the effectiveness of overminus spectacles in treating IXT, particularly the effect on control after overminus treatment has been discontinued.