Susanna M. Tamkins

Randomized clinical trial of treatments for symptomatic convergence insufficiency in children

OBJECTIVE To compare home-based pencil push-ups (HBPP), home-based computer vergence/accommodative therapy and pencil push-ups (HBCVAT+), office-based vergence/accommodative therapy with home reinforcement (OBVAT), and office-based placebo therapy with home reinforcement (OBPT) as treatments for symptomatic convergence insufficiency. METHODS In a randomized clinical trial, 221 children aged 9 to 17 years with symptomatic convergence insufficiency were assigned to 1 of 4 treatments. MAIN OUTCOME MEASURES Convergence Insufficiency Symptom Survey score after 12 weeks of treatment. Secondary outcomes were near point of convergence and positive fusional vergence at near. RESULTS After 12 weeks of treatment, the OBVAT groups mean Convergence Insufficiency Symptom Survey score (15.1) was statistically significantly lower than those of 21.3, 24.7, and 21.9 in the HBCVAT+, HBPP, and OBPT groups, respectively (P < .001). The OBVAT group also demonstrated a significantly improved near point of convergence and positive fusional vergence at near compared with the other groups (P <or= .005 for all comparisons). A successful or improved outcome was found in 73%, 43%, 33%, and 35% of patients in the OBVAT, HBPP, HBCVAT+, and OBPT groups, respectively. CONCLUSIONS Twelve weeks of OBVAT results in a significantly greater improvement in symptoms and clinical measures of near point of convergence and positive fusional vergence and a greater percentage of patients reaching the predetermined criteria of success compared with HBPP, HBCVAT+, and OBPT. Application to Clinical Practice Office-based vergence accommodative therapy is an effective treatment for children with symptomatic convergence insufficiency. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00338611.

Patching vs atropine to treat amblyopia in children aged 7 to 12 years: A randomized trial

OBJECTIVE To compare patching with atropine eyedrops in the treatment of moderate amblyopia (visual acuity, 20/40-20/100) in children aged 7 to 12 years. METHODS In a randomized, multicenter clinical trial, 193 children with amblyopia were assigned to receive weekend atropine or patching of the sound eye 2 hours per day. Main Outcome Measure Masked assessment of visual acuity in the amblyopic eye using the electronic Early Treatment Diabetic Retinopathy Study testing protocol at 17 weeks. RESULTS At 17 weeks, visual acuity had improved from baseline by an average of 7.6 letters in the atropine group and 8.6 letters in the patching group. The mean difference between groups (patching - atropine) adjusted for baseline acuity was 1.2 letters (ends of complementary 1-sided 95% confidence intervals for noninferiority, -0.7, 3.1 letters). This difference met the prespecified definition for equivalence (confidence interval <5 letters). Visual acuity in the amblyopic eye was 20/25 or better in 15 participants in the atropine group (17%) and 20 in the patching group (24%; difference, 7%; 95% confidence interval, -3% to 17%). CONCLUSIONS Treatment with atropine or patching led to similar degrees of improvement among 7- to 12-year-olds with moderate amblyopia. About 1 in 5 achieved visual acuity of 20/25 or better in the amblyopic eye. CLINICAL RELEVANCE Atropine and patching achieve similar results among older children with unilateral amblyopia. TRIAL REGISTRATION (clinicaltrials.gov) Identifier: NCT00315328.

Retinal Nerve Fiber Layer Thickness in Amblyopic Eyes

PURPOSE To compare the peripapillary retinal nerve fiber layer (RNFL) thickness of amblyopic and fellow eyes. We hypothesized that the RNFL of the amblyopic eye may be thinner. DESIGN Prospective, cross-sectional, observational case series. METHODS Optical coherence tomography of the peripapillary RNFL thickness of amblyopic and fellow eyes was performed in 37 patients 7 to 12 years of age (mean age +/- standard deviation, 9.2 +/- 1.5 years) with unilateral strabismic, anisometropic, or combined-mechanism amblyopia enrolled in a randomized treatment trial. RESULTS Mean global RNFL thickness of the amblyopic and fellow eyes was 111.4 and 109.6 microm, respectively (mean difference, 1.8 microm thicker in the amblyopic eyes; 95% confidence interval, -0.6 to 4.3 microm). The amblyopic eye was 8 microm or more thicker than the fellow eye in 9 patients (24%); the fellow eye was 8 microm or more thicker than the amblyopic eye in 2 patients (5%); and the difference was within test-retest variability (7 microm) in 26 patients (70%). CONCLUSIONS Our findings do not indicate that peripapillary RNFL thickness is thinner in eyes with moderate amblyopia compared with their fellow eyes.

The convergence insufficiency treatment trial: Design, methods, and baseline data

Objective: This report describes the design and methodology of the Convergence Insufficiency Treatment Trial (CITT), the first large-scale, placebo-controlled, randomized clinical trial evaluating treatments for convergence insufficiency (CI) in children. We also report the clinical and demographic characteristics of patients. Methods: We prospectively randomized children 9 to 17 years of age to one of four treatment groups: 1) home-based pencil push-ups, 2) home-based computer vergence/accommodative therapy and pencil push-ups, 3) office-based vergence/accommodative therapy with home reinforcement, 4) office-based placebo therapy. Outcome data on the Convergence Insufficiency Symptom Survey (CISS) score (primary outcome), near point of convergence (NPC), and positive fusional vergence were collected after 12 weeks of active treatment and again at 6 and 12 months posttreatment. Results: The CITT enrolled 221 children with symptomatic CI with a mean age of 12.0 years (SD = +2.3). The clinical profile of the cohort at baseline was 9Δ exophoria at near (+/− 4.4) and 2Δ exophoria (+/−2.8) at distance, CISS score = 30 (+/−9.0), NPC = 14 cm (+/− 7.5), and near positive fusional vergence break = 13 Δ (+/− 4.6). There were no statistically significant nor clinically relevant differences between treatment groups with respect to baseline characteristics (p > 0.05).Conclusion: Hallmark features of the study design include formal definitions of conditions and outcomes, standardized diagnostic and treatment protocols, a placebo treatment arm, masked outcome examinations, and the CISS score outcome measure. The baseline data reported herein define the clinical profile of those enrolled into the CITT.

Validity of the convergence insufficiency symptom survey: a confirmatory study.

Purpose. The objectives of the present study were to evaluate whether investigator bias influenced the Convergence Insufficiency Symptom Survey (CISS) scores of children with normal binocular vision (NBV) in our original validation study, reevaluate the usefulness of the cutoff score of 16, and reexamine the validity of the CISS. Methods. Six clinical sites participating in the Convergence Insufficiency Treatment Trial (CITT) enrolled 46 children 9 to <18 years with NBV. Examiners masked to the child’s binocular vision status administered the CISS. The mean CISS score was compared with that from the children with NBV in the original, unmasked CISS study and also to that of the 221 symptomatic convergence insufficiency (CI) children enrolled in the CITT. Results. The mean (±standard deviation) CISS score for 46 subjects with NBV was 10.4 (±8.1). This was comparable with our prior unmasked NBV study (mean = 8.1 (±6.2); p = 0.11) but was significantly different from that of the CITT CI group (mean = 29.8 ± 9.0; p < 0.001). Eighty-three percent of these NBV subjects scored <16 on the CISS, which is not statistically different from the 87.5% found in the original unmasked study (p = 0.49). Conclusions. Examiner bias did not affect the CISS scores for subjects with NBV in our prior study. The CISS continues to be a valid instrument for quantifying symptoms in 9 to <18-year-old children. These results also confirm the validity of a cut-point of ≥16 in distinguishing children with symptomatic CI from those with NBV.

Stereoacuity in children with anisometropic amblyopia

PURPOSE To determine factors associated with pretreatment and posttreatment stereoacuity in subjects with moderate anisometropic amblyopia. METHODS Data for subjects enrolled in seven studies conducted by the Pediatric Eye Disease Investigator Group were pooled. The sample included 633 subjects aged 3 to <18 years with anisometropic amblyopia, no heterotropia observed by cover test, and baseline amblyopic eye acuity of 20/100 or better. A subset included 248 subjects who were treated with patching or Bangerter filters and had stereoacuity testing at both the baseline and outcome examinations. Multivariate regression models identified factors associated with baseline stereoacuity and with outcome stereoacuity as measured by the Randot Preschool Stereoacuity test. RESULTS Better baseline stereoacuity was associated with better baseline amblyopic eye acuity (P < 0.001), less anisometropia (P = 0.03), and anisometropia due to astigmatism alone (P < 0.001). Better outcome stereoacuity was associated with better baseline stereoacuity (P < 0.001) and better amblyopic eye acuity at outcome (P < 0.001). Among 48 subjects whose amblyopic eye visual acuity at outcome was 20/25 or better and within one line of the fellow eye, stereoacuity was worse than that of children with normal vision of the same age. CONCLUSIONS In children with anisometropic amblyopia of 20/40 to 20/100 inclusive, better posttreatment stereoacuity is associated with better baseline stereoacuity and better posttreatment amblyopic eye acuity. Even if their visual acuity deficit resolves, many children with anisometropic amblyopia have stereoacuity worse than that of nonamblyopic children of the same age.

Optical treatment of strabismic and combined strabismic-anisometropic amblyopia.

OBJECTIVE To determine visual acuity improvement in children with strabismic and combined strabismic-anisometropic (combined-mechanism) amblyopia treated with optical correction alone and to explore factors associated with improvement. DESIGN Prospective, multicenter, cohort study. PARTICIPANTS We included 146 children 3 to <7 years old with previously untreated strabismic amblyopia (n = 52) or combined-mechanism amblyopia (n = 94). METHODS Optical treatment was provided as spectacles (prescription based on a cycloplegic refraction) that were worn for the first time at the baseline visit. Visual acuity with spectacles was measured using the Amblyopia Treatment Study HOTV visual acuity protocol at baseline and every 9 weeks thereafter until no further improvement in visual acuity. Ocular alignment was assessed at each visit. MAIN OUTCOME MEASURES Visual acuity 18 weeks after baseline. RESULTS Overall, amblyopic eye visual acuity improved a mean of 2.6 lines (95% confidence interval [CI], 2.3-3.0), with 75% of children improving ≥ 2 lines and 54% improving ≥ 3 lines. Resolution of amblyopia occurred in 32% (95% CI, 24%-41%) of the children. The treatment effect was greater for strabismic amblyopia than for combined-mechanism amblyopia (3.2 vs 2.3 lines; adjusted P = 0.003). Visual acuity improved regardless of whether eye alignment improved. CONCLUSIONS Optical treatment alone of strabismic and combined-mechanism amblyopia results in clinically meaningful improvement in amblyopic eye visual acuity for most 3- to <7-year-old children, resolving in at least one quarter without the need for additional treatment. Consideration should be given to prescribing refractive correction as the sole initial treatment for children with strabismic or combined-mechanism amblyopia before initiating other therapies. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Vision Therapy/Orthoptics for Symptomatic Convergence Insufficiency in Children: Treatment Kinetics

Purpose. To evaluate the kinetics of change in symptoms and signs of convergence insufficiency (CI) during 12 weeks of treatment with commonly prescribed vision therapy/orthoptic treatment regimens. Methods. In a randomized clinical trial, 221 children aged 9 to 17 years with symptomatic CI were assigned to home-based pencil push-ups (HBPP), home-based computer vergence/accommodative therapy and pencil push-ups (HBCVAT+), office-based vergence/accommodative therapy with home reinforcement (OBVAT), or office-based placebo therapy with home reinforcement (OBPT). Symptoms and signs were measured after 4, 8, and 12 weeks of treatment. The outcome measures were the mean CI Symptom Survey (CISS), near point of convergence (NPC), positive fusional vergence (PFV), and proportions of patients who were classified as successful or improved based on a composite measure of CISS, NPC, and PFV. Results. Only the OBVAT group showed significant improvements in symptoms between each visit (p < 0.001). Between weeks 8 and 12, all groups showed a significant improvement in symptoms. Between-group differences were apparent by week 8 (p = 0.037) with the fewest symptoms in the OBVAT group. For each group, the greatest improvements in NPC and PFV were achieved during the first 4 weeks. Differences between groups became apparent by week 4 (p < 0.001), with the greatest improvements in NPC and PFV in the OBVAT group. Only the OBVAT group continued to show significant improvements in PFV at weeks 8 and 12. The percentage of patients classified as “successful” or “improved” based on our composite measure increased in all groups at each visit. Conclusions. The rate of improvement is more rapid for clinical signs (NPC and PFV) than for symptoms in children undergoing treatment for CI. OBVAT results in a more rapid improvement in symptoms, NPC and PFV, and a greater percentage of patients reaching pre-determined criteria of success when compared with HBPP, HBCVAT+, or OBPT.

A randomized trial comparing part-time patching with observation for children 3 to 10 years of age with intermittent exotropia

OBJECTIVE To determine the effectiveness of prescribed part-time patching for treatment of intermittent exotropia (IXT) in children. DESIGN Multicenter, randomized clinical trial. PARTICIPANTS Three hundred fifty-eight children 3 to <11 years of age with previously untreated (except for refractive correction) IXT and near stereoacuity of 400 seconds of arc or better were enrolled. Intermittent exotropia met the following criteria: (1) IXT at distance OR constant exotropia at distance and either IXT or exophoria at near; (2) exodeviation (tropia or phoria) of at least 15 prism diopters (PD) at distance or near by prism and alternate cover test (PACT); and (3) exodeviation of at least 10 PD at distance by PACT. METHODS Participants were assigned randomly either to observation (no treatment for 6 months) or to patching for 3 hours daily for 5 months, with a 1-month washout period of no patching before the 6-month primary outcome examination. MAIN OUTCOME MEASURES The primary outcome was deterioration at either the 3-month or the 6-month follow-up visit, defined as: (1) constant exotropia measuring at least 10 PD at distance and near by simultaneous prism and cover test, and/or (2) near stereoacuity decreased by at least 2 octaves from baseline, both assessed by a masked examiner and confirmed by a retest. Participants who were prescribed any nonrandomized treatment without first meeting either deterioration criteria also were counted as having deteriorated. RESULTS Of the 324 participants (91%) completing the 6-month primary outcome examination, deterioration occurred in 10 of the 165 participants (6.1%) in the observation group (3 of these 10 started treatment without meeting deterioration criteria) and in 1 of the 159 participants (0.6%) in the part-time patching group (difference, 5.4%; lower limit of 1-sided exact 95% confidence interval, 2.0%; P = 0.004, 1-sided hypothesis test). CONCLUSIONS Deterioration of previously untreated childhood IXT over a 6-month period is uncommon with or without patching treatment. Although there is a slightly lower deterioration rate with patching, both management approaches are reasonable for treating children 3 to 10 years of age with IXT.

Visual acuity through Bangerter filters in nonamblyopic eyes

PURPOSE To describe the amount of visual acuity degradation induced by Bangerter filters in the better seeing eye and to evaluate its stability over time in children with moderate amblyopia. METHODS Visual acuity with and without a Bangerter filter was measured in the nonamblyopic eye of 186 children with moderate amblyopia who were then treated with either patching or the Bangerter filters. A 0.2 filter was used for amblyopia of 20/80 and a 0.3 filter for amblyopia from 20/40 to 20/63. For the 89 children randomized to Bangerter filters, visual acuity was also measured in the nonamblyopic eye with and without the filters at both 6 weeks and 12 weeks after initiating treatment. RESULTS Mean degradation in visual acuity of the nonamblyopic eye at baseline was 5.1 logMAR lines with the 0.2 filter and 4.8 logMAR lines with the 0.3 filter. The degradation with each filter did not always agree with the manufacturers specifications. Over time, the amount of degradation with the filters decreased. CONCLUSIONS The 0.2 and 0.3 Bangerter filters degrade nonamblyopic eye visual acuity sufficiently in amblyopic children. Because the amount of degradation decreases over time, it is recommended to periodically apply a new filter when using this type of amblyopia treatment.