The effect on pediatric ophthalmologists of the randomized trial of patching regimens for treatment of moderate amblyopia.

PURPOSE: To investigate the implementation of the recommendations of the randomized trial of patching regimens for treatment of moderate amblyopia in children. METHODS: A questionnaire was e-mailed to 380 members of the American Association for Pediatric Ophthalmology and Strabismus. RESULTS: Ninety responses were received. The majority of questionnaire respondents did not alter their clinical practice of patching subsequent to publication of the results of the patching trial. Thirty-nine percent made no modification whatsoever; an additional 33% made rare adjustments, and only 12% claimed to have adapted the amount of patching hours to the recommendations of the study. CONCLUSIONS: It is evident from the questionnaire results that the majority of pediatric ophthalmologists that replied to the questionnaire did not alter their clinical practice of patching subsequent to publication of the results of the patching trial.     

A randomized pilot study of near activities versus non-near activities during patching therapy for amblyopia.

BACKGROUND: To plan a future randomized clinical trial, we conducted a pilot study to determine whether children randomized to near or non-near activities would perform prescribed activities. A secondary aim was to obtain a preliminary estimate of the effect of near versus non-near activities on amblyopic eye visual acuity, when combined with 2 hours of daily patching. METHODS: Sixty-four children, 3 to less than 7 years of age, with anisometropic, strabismic, or combined amblyopia (20/40 to 20/400) were randomly assigned to receive either 2 hours of daily patching with near activities or 2 hours of daily patching without near activities. Parents completed daily calendars for 4 weeks recording the activities performed while patched and received a weekly telephone call in which they were asked to describe the activities performed during the previous 2 hours of patching. Visual acuity was assessed at 4 weeks. RESULTS: The children assigned to near visual activities performed more near activities than those assigned to non-near activities (by calendars, mean 1.6 +/- 0.5 hours versus 0.2 +/- 0.2 hours daily, P < 0.001; by telephone interviews, 1.6 +/- 0.4 hours versus 0.4 +/- 0.5 hours daily, P < 0.001). After 4 weeks of treatment, there was a suggestion of greater improvement in amblyopic eye visual acuity in those assigned to near visual activities (mean 2.6 lines versus 1.6 lines, P = 0.07). The treatment group difference in visual acuity was present for patients with severe amblyopia but not moderate amblyopia. CONCLUSIONS: Children patched and instructed to perform near activities for amblyopia spent more time performing those near activities than children who were instructed to perform non-near activities. Our results suggest that performing near activities while patched may be beneficial in treating amblyopia. Based on our data, a formal randomized amblyopia treatment trial of patching with and without near activities is both feasible and desirable.     

A randomized trial of prescribed patching regimens for treatment of severe amblyopia in children

OBJECTIVE: To compare full-time patching (all hours or all but 1 hour per day) to 6 hours of patching per day, as prescribed treatments for severe amblyopia in children younger than 7 years. DESIGN: Prospective, randomized multicenter clinical trial (32 sites). PARTICIPANTS: One hundred seventy-five children younger than 7 years with amblyopia in the range of 20/100 to 20/400. INTERVENTION: Randomization either to full-time patching or to 6 hours of patching per day, each combined with at least 1 hour of near-visual activities during patching. MAIN OUTCOME MEASURE: Visual acuity in the amblyopic eye after 4 months. RESULTS: Visual acuity in the amblyopic eye improved a similar amount in both groups. The improvement in the amblyopic eye acuity from baseline to 4 months averaged 4.8 lines in the 6-hour group and 4.7 lines in the full-time group (P = 0.45). CONCLUSION: Six hours of prescribed daily patching produces an improvement in visual acuity that is of similar magnitude to the improvement produced by prescribed full-time patching in treating severe amblyopia in children 3 to less than 7 years of age.     

The effect of occlusive patching on visually-directed tasks.

PURPOSE: Occlusive patching is used to treat a variety of ocular conditions. A paucity of literature exists regarding the effects of occlusion on functional tasks and driving performance. We investigated the immediate effects of occlusive patching on a variety of visually dependent tasks as well as driving performance on a simulator. METHODS: Thirty normally sighted subjects were examined in a prospective randomized manner. All subjects underwent a complete medical history and eye examination. All subjects performed a variety of near tasks and drove a driving simulator with and without patching. The tasks included traditional clinical depth tests, tests of visual memory, scanning, and tracking, and gross and fine-motor abilities. All subjects filled out a questionnaire relating to their perception of the effects of patching on functional tasks and driving ability. RESULTS: Visual memory, scanning, tracking, and perceptual constancy were unaffected by patching. However, there were significant differences between the patched and unpatched conditions for four of five of the three-dimensional visual coordination tasks. Eight of 19 (42%) of the fine-motor tasks and 4 of 9 gross-motor tasks (44%) showed significant differences between the patched and unpatched conditions. A greater frequency of out of lane events and more abrupt braking profiles were seen when subjects drove monocularly rather than binocularly. CONCLUSIONS: Sudden occlusion immediately changes perceptual ability by decreasing visual field and eliminating stereoacuity. This has important implications for the performance of everyday tasks.     

"Instant vision" compared with postoperative patching: clinical evaluation and patient satisfaction after bilateral cataract surgery

PURPOSE: To compare two methods of postoperative dressing regimen: patching vs "instant vision" without patch. DESIGN: Prospective randomized clinical trial. METHODS: Sixty consecutive hospitalized, nonambulatory patients with cataract surgery under topical anesthesia on both eyes at different days were enrolled prospectively. In randomized order, one eye was patched for the first 24 hours postoperatively; the other eye was left open without patch to obtain "instant vision." Both eyes received the same anti-inflammatory and antibiotic drop therapy. RESULTS: Twenty-four hours postoperatively, no significant differences between patching and "instant vision" could be found for corrected and uncorrected visual acuity, corneal epithelial defects, conjunctival inflammation, anterior chamber flare, and intraocular pressure (P > .05). During the first 24 hours postoperatively, all tear film parameters were significantly worse in the "instant vision" eyes (P < .001), indicating a transient tear film instability. During the first four hours after cataract surgery, pain scores in the "instant vision" eyes were significantly higher than in the patched eyes (P < .001). Eight hours postoperatively and later, there were no significant differences in any pain scores (P > .05). After experiencing both methods, 27% of the patients subjectively rated the two methods as equivalent; 8% of the patients preferred "instant vision." Despite of the benefits of immediately improved orientation, 65% of the tested patients preferred patching to "instant vision" because of lower pain and foreign body sensations and psychologic arguments. CONCLUSIONS: The clinical examinations showed that both methods were equally safe for postoperative therapy. However, further efforts have to be made to increase the patients' comfort with "instant vision" in the first hours after cataract surgery.     

Risk of amblyopia recurrence after cessation of treatment.

BACKGROUND: Although amblyopia can be successfully treated with patching or atropine, there have been few prospective studies of amblyopia recurrence once treatment is discontinued. METHODS: We enrolled 156 children with successfully treated anisometropic or strabismic amblyopia (145 completed follow-up), who were younger than 8 years of age and who received continuous amblyopia treatment for the previous 3 months (prescribed at least 2 hours of daily patching or prescribed at least one drop of atropine per week) and who had improved at least 3 logMAR levels during the period of continuous treatment. Patients were followed off treatment for 52 weeks to assess recurrence of amblyopia, defined as a 2 or more logMAR level reduction of visual acuity from enrollment, confirmed by a second examination. Recurrence was also considered to have occurred if treatment was restarted because of a nonreplicated 2 or more logMAR level reduction of visual acuity. RESULTS: Recurrence occurred in 35 (24%) of 145 cases (95% confidence interval 17% to 32%) and was similar in patients who stopped patching (25%) and in patients who stopped atropine (21%). In patients treated with moderately intense patching (6 to 8 hours per day), recurrence was more common (11 of 26; 42%) when treatment was not reduced prior to cessation than when treatment was reduced to 2 hours per day prior to cessation (3 of 22; 14%, odds ratio 4.4, 95% confidence interval 1.0 to 18.7). CONCLUSIONS: Approximately one fourth of successfully treated amblyopic children experience a recurrence within the first year off treatment. For patients treated with 6 or more hours of daily patching, our data suggest that the risk of recurrence is greater when patching is stopped abruptly rather than when it is reduced to 2 hours per day prior to cessation. A randomized clinical trial of no weaning versus weaning in successfully-treated amblyopia is warranted to confirm these observational findings.     

Effectiveness of the addition of citicoline to patching in the treatment of amblyopia around visual maturity: A randomized controlled trial

Aim:

To study the effectiveness of the addition of citicoline to patching in the treatment of amblyopia in the age group of 4-13 years.

Materials and Methods:

A randomized controlled trial, which included patients who were randomly divided into two groups. Both the groups received patching therapy till plateau was achieved in phase 1 of the study. Then in phase 2, group I received citicoline plus patching and group II continued to receive only patching.

Outcome Measures:

Outcome was measured by the visual acuity in logMAR every month in phase 1 till plateau was achieved and then for 12 months in phase 2.

Results:

No significant difference was found in the mean visual acuities in these two groups in phase 1 till plateau was reached. In phase 2, for the initial four months, there was no significant difference in the visual acuities in these two groups, at the respective intervals. However, five months onward, up to 12 months, there was a significant difference in the visual acuities in these groups. The result was the same in younger patients (< seven years of age) as well as in older patients (> seven years of age). In phase 2, the mean proportional improvement in group I was significantly more than that in group II, at two months and onward, at the respective intervals.

Conclusion:

The improvement in visual acuity with citicoline plus patching was significantly more than that with patching alone, in one year of treatment.     

Evaluation of eye patching after cataract surgery in topical anesthesia

BACKGROUND: Although postoperative eye patching is a common practice its background is not well known. Therefore the necessity of eye patching after cataract surgery in topical anesthesia from the medical point of view and the patients' subjective opinion was studied. PATIENTS AND METHODS: In this prospective and randomized study 133 patients received after cataract surgery either no covering of the eye (group1), a transparent eye shield for four hours (group 2), an eye pad for four hours (group 3) or an eye pad until the next morning (group 4). Clinical findings were noted and local symptoms, such as pain, foreign body sensation, tearing and photophobia were documented on a visual analogue scale (0 - 10). Furthermore, a questionnaire concerning the subjective opinion was handed out to the patient. RESULTS: The clinical findings revealed no significant differences between the groups. The mean values for local pain were 0.94 +/- 1.56, for the foreign body sensation 1.41 +/- 2.02, for tearing 0.99 +/- 1.8 and for photophobia 1.05 +/- 1.99. Comparing the groups there was significantly more pain and foreign body sensation reported by the patients in group 3, who received eye patching for 4 hours. 91 % of the unpatched patients had no discomfort, whereas 53 % of the patients wearing an eye pad until the next morning considered it as unnecessary. CONCLUSION: After cataract surgery in topical anesthesia only mild symptoms were noted. There were no significant differences between the groups in the objective clinical findings and the subjective feeling. These results indicate that after cataract surgery eye patching could be unnecessary.     

The emotional impact of amblyopia treatment in preschool children: randomized controlled trial

PURPOSE: To investigate the emotional status of children undergoing active treatment for amblyopia. DESIGN: Postal survey, in the context of a prospective, multicenter, randomized controlled trial. PARTICIPANTS: Parents of 177 children with a unilateral visual impairment referred from preschool vision screening. The children had been recruited to a randomized controlled trial of treatment for unilateral visual impairment and randomly assigned to receive either glasses with or without patches, glasses alone, or treatment deferred for 1 year. METHODS: A self-completion questionnaire, including a psychometric behavioral scale, was sent to the parents of all children recruited to the trial at age 4 years, to 66 whose deferred treatment began at age 5 years, and finally to 151 remaining in the trial at the end of follow-up. MAIN OUTCOME MEASURES: Mean scores per treatment group on the Revised Rutter Parent Scale for Preschool Children. Comparison of parent responses to questions assessing the child's general well-being and difficulties associated with treatment. RESULTS: Completed questionnaires were returned for 144 of 177 (81%) children at a mean age (standard deviation) of 48 months (5.0), for 45 of 66 (68%) at a mean age of 61 months (5.8), and for 78 of 151 (52%) at a mean age of 67 months (5.0). Most parents reported having difficulty with patching their child regardless of age (77% at age 4 years and 73% at age 5 years), with fewer reporting difficulties with glasses alone (42% and 53%, respectively). Children were significantly more upset by patching than by glasses only (chi-square test, P = 0.03 for age 4 years and P = 0.01 for age 5 years), as were the parents of 4-year-olds (chi-square test, P = 0.01). Most parents thought their children were happy, cooperative, and good tempered, and behavioral scores did not differ between treatment groups. CONCLUSIONS: Treatment for unilateral visual impairment is not easy to implement and is commonly associated with some degree of distress. Despite this, no impact on the child's global well-being or behavior was seen either during or after the treatment period.     

不同遮盖方式治疗弱视的临床观察

目的比较每天遮盖6小时和12小时治疗3～8岁单眼弱视患儿的疗效。方法对71例3～8岁单眼弱视患儿采用遮盖联合精细训练的方法进行治疗,随机分为每天遮盖6小时组和每天遮盖12小时组,精细训练方法两组相同。每月复查一次视力,连续随诊6个月。结果每天遮盖6小时组和每天遮盖12小时组,治疗6个月后视力提高3行及3行以上的分别为63.4%和66.7%。两组中,轻度和中度弱视患儿的视力提高程度无统计学差别(P>0.05)。重度弱视患儿的视力提高程度有统计学差异(P<0.05)。结论治疗3～8岁弱视患儿,建议对重度弱视患者采用每天遮盖12小时的方式,对轻中度弱视患者采用每天遮盖6小时的方式。     

儿童白内障手术并发症的研究进展

儿童白内障手术步骤较多,儿童眼的解剖学特点及白内障的不同状态常常需要变更手术操作技术,术中、术后并发症较成人多,术后随访观察须严密,视力重建需要家长的长期配合与付出,这些都使儿童白内障的治疗具有挑战性.近年来,儿童白内障手术并发症的研究领域有了以下更新:23G及25G玻璃体切割机用于儿童白内障手术,使儿童白内障摘出术实现无缝线;多中心、前瞻性随机对照研究——美国婴儿无晶状体眼的治疗项目(IATS)的近期、中期研究结果已经逐步报道;大样本、远期观察的回顾性研究对儿童白内障术后眼内出血、眼内炎、青光眼相关不良事件、视轴再混浊、视网膜脱离等并发症及其结局都有了新的认识.本文回顾近年相关文献,就儿童白内障术中、术后并发症进行综述,帮助临床医师进一步理解和重视儿童白内障手术并发症及其防范、随访及处理.     

Clinical predictors of the optimal spectacle correction for comfort performing desktop tasks

Background: The best strategy for spectacle correction of presbyopia for near tasks has not been determined. Methods: Thirty volunteers over the age of 40 years were tested for subjective accommodative amplitude, pupillary size, fusional vergence, interpupillary distance, arm length, preferred working distance, near and far visual acuity and preferred reading correction in the phoropter and trial frames. Subjects performed near tasks (reading, writing and counting change) using various spectacle correction strengths. Predictors of the correction maximising near task comfort were determined by multivariable linear regression. Results: The mean age was 54.9 years (range 43 to 71) and 40 per cent had diabetes. Significant predictors of the most comfortable addition in univariate analyses were age (p < 0.001), interpupillary distance (p = 0.02), fusional vergence amplitude (p = 0.02), distance visual acuity in the worse eye (p = 0.01), vision at 40 cm in the worse eye with distance correction (p = 0.01), duration of diabetes (p = 0.01), and the preferred correction to read at 40 cm with the phoropter (p = 0.002) or trial frames (p < 0.001). Target distance selected wearing trial frames (in dioptres), arm length, and accommodative amplitude were not significant predictors (p > 0.15). The preferred addition wearing trial frames holding a reading target at a distance selected by the patient was the only independent predictor. Excluding this variable, distance visual acuity was predictive independent of age or near vision wearing distance correction. The distance selected for task performance was predicted by vision wearing distance correction at near and at distance. Conclusions: Multivariable linear regression can be used to generate tables based on distance visual acuity and age or near vision wearing distance correction to determine tentative near spectacle addition. Final spectacle correction for desktop tasks can be estimated by subjective refraction with trial frames.     

The course of moderate amblyopia treated with patching in children: experience of the amblyopia treatment study

Purpose

To assess the course of the response to patching treatment of moderate amblyopia and to assess factors predictive of the response in children 3 years old to younger than 7 years old.

Design

Multicenter, randomized clinical trial comparing patching and atropine (one of the amblyopia treatment studies).

Methods

A total of 209 children 3 years old to younger than 7 years of age with amblyopia in the range of 20/40 to 20/100 from the patching treatment arm of this trial were treated with patching of the sound eye from 6 hours per day up to all waking hours. Follow-up examinations were performed at 5 weeks, 16 weeks, and 6 months. The primary outcome measure was visual acuity in the amblyopic eye at 6 months.

Results

After 5 weeks of treatment, mean amblyopic eye acuity improved from baseline by 2.2 lines. For patients with baseline acuity of 20/80 or 20/100, a greater number of hours of prescribed patching was associated with greater improvement in the first 5 weeks (P = .05). However, this relationship was not present when baseline acuity was 20/40 to 20/60 (P = .57). At 6 months, visual acuity was improved from baseline by a mean of 3.1 lines, with the amount of improvement no longer related to the number of hours patching prescribed at baseline (P = .93). Among the 157 patients improving at least 3 lines from baseline, 15% achieved their maximum improvement by 5 weeks and 52% by 16 weeks. None of the demographic or clinical factors assessed was predictive of the response to treatment.

Conclusions

In the treatment of moderate amblyopia, a beneficial effect of patching is present throughout the age range of 3 years old to younger than 7 years old and the acuity range of 20/40 to 20/100. At 6 months, the amount of improvement appears to be similar when 6 hours of daily patching are initially prescribed vs a greater number of hours. However, when the baseline acuity is 20/80 to 20/100, a greater number of hours of prescribed patching may improve acuity faster.     

Two‐year follow‐up of a randomized trial of spectacles plus alternate‐day patching to treat strabismic amblyopia

Purpose: To compare spectacles plus alternate‐day patching for 8 hr or more with spectacles plus patching for 8 hr or more 6 days weekly to treat strabismic amblyopia 1 year after a 1‐year randomized trial. Methods: Forty children (mean age, 4.3 years) participated. Refractive correction was provided. The children were assigned to alternate‐day patching for 8 hr or more or patching for 8 hr or more daily 6 days weekly. VA, binocular function, and refractive errors were measured after 2 years. The main outcome measure was the median VA change in the amblyopic eye after 2 years. Results: The median VA change in the amblyopic eye at the 2‐year visit was significantly (p = 0.0453) greater with alternate‐day patching (0.8 log unit) versus patching daily 6 days weekly (0.6 log unit). The final median VA in the amblyopic eyes was 0.0 logMAR in the alternate‐day patching group and 0.1 logMAR in the daily patching group. Binocular function improved with both treatments. The median spherical equivalent (SE) refractive error increased in the fellow eyes (alternate‐day patching, p < 0.0001; patching daily 6 days weekly, p = 0.0033); no change was found in the amblyopic eyes in either group. Conclusions: The magnitude of the VA change 2 years after treatment with spectacles plus alternate‐day patching for 8 hr or more was significantly greater than with spectacles plus daily patching for 8 hr or more 6 days weekly for strabismic amblyopia. However, the final median VA did not differ significantly between the two treatments.     

The management of posterior polar cataract: the role of patching and grading

BACKGROUND: The milder form of posterior polar cataract is often discovered late in preschool children if secondary symptoms like strabismus are not present. The question addressed in this paper is: do such children still profit from orthoptic and surgical treatment? PATIENTS AND METHODS: This was a retrospective study of the data from 13 patients, median age 4 years (range: 1 month to 12 years), with a mean follow-up of 4 years. Four changes to the red reflex were introduced. RESULTS: Surgery followed from two weeks to three years after starting occlusion therapy. Before therapy, the best visual acuity was 0.3 and the worst 0.06 (median 0.16). A median of four years after starting therapy, the visual acuity ranged from 0.9 to 0.4 (median 0.6). CONCLUSION: All milder cases profited from the treatment despite its late start. An earlier discovery would improve the prognosis. In any case, however, ophthalmologists should be encouraged to try patching before resorting to surgery.     

Optical penalization can improve vision after occlusion treatment

BACKGROUND: Optical penalization (OP) has previously been shown to successfully maintain vision in amblyopic eyes of older children when patching compliance is poor and when vision decreases once patching is discontinued. This study shows that the final vision in optically penalized eyes is often better than the vision obtained after patching alone. SUBJECTS AND METHODS: During the 5-year period from January 1992 to February 1997, 28 children aged between 3.7 and 8.2 years (average age, 6.5+/-1.1 years) were optically penalized for an average of 1.5+/-0.75 years. The maximum length of penalization was 3.3 years, whereas the minimum time was 6 months. There were 21 children with strabismic amblyopia and 7 children with anisometropic amblyopia. All 28 children had worn a patch to achieve their best visual levels and then had shown a loss of best vision when occlusion was stopped. Patching was usually resumed and continued until the previous best vision was obtained; at this point OP was started to "maintain" vision. Eighteen of the 28 children have discontinued penalization and have been followed up an average of 1(1/2) years. RESULTS: Twenty-six (93%) of the 28 patients showed an increase in best vision from that found at the conclusion of patching, and 2 patients maintained their vision at the initial level. The average visual acuity at the start of penalization was 20/50 (0.42+/-0.11 logarithm of the minimum angle of resolution [log MAR]). Final average visual acuity was 20/27 (0.15+/-0.12 log MAR). The average increase in vision was nearly 3 lines or 0.27+/-0.12 log MAR. CONCLUSION: OP alone (without the use of pharmacologic agents such as atropine) not only maintains vision after patching therapy, but also appears to improve the final visual outcome.     

弱视遮盖治疗的新进展

遮盖是弱视治疗的有效手段，但具体效果还因情况而异。重度弱视患者全天遮盖和6h遮盖的视力提高相近．中度弱视患者2h和6h遮盖治疗的效果没有明显差异。既往认为的弱视类型对治疗结果的影响受到挑战，有研究发现其对治疗结果的影响作用并不明显。遮盖与阿托品疗法对中度弱视治疗的效果是相近的。有试验性研究发现遮盖伴精细行为训练能提高遮盖治疗的效果。终止治疗的方法可能也是影响复发的一个因素。本文扼要综述弱视遮盖治疗的最新进展。     

Exercise alone impacts short-term adult visual neuroplasticity in a monocular deprivation paradigm

Adult homeostatic visual plasticity can be induced by short-term patching, heralded by a shift in ocular dominance in favor of the deprived eye after monocular occlusion. The potential to boost visual neuroplasticity with environmental enrichment such as exercise has also been explored; however, the results are inconsistent, with some studies finding no additive effect of exercise. Studies to date have only considered the effect of patching alone or in combination with exercise. Whether exercise alone affects typical outcome measures of experimental estimates of short-term visual neuroplasticity is unknown. We therefore measured binocular rivalry in 20 healthy young adults (20–34 years old) at baseline and after three 2-hour interventions: patching (of the dominant eye) only, patching with exercise, and exercise only. Consistent with previous work, the patching interventions produced a shift in ocular dominance toward the deprived (dominant) eye. Mild- to moderate-intensity exercise in the absence of patching had several effects on binocular rivalry metrics, including a reduction in the dominant eye percept. The proportion of mixed percept and the time to first switch (onset rivalry) did not change from baseline across all interventions. Thus, we demonstrate that exercise alone can impact binocular rivalry outcomes measures. We did not observe a synergistic effect between patching and exercise in our data.     

The Effect of Amblyopia Therapy on Ocular Alignment

PURPOSE: We sought to describe the change in ocular alignment at 2 years after treatment of amblyopia in children younger than 7 years of age at enrollment. METHODS: A randomized clinical trial of patching versus atropine for 6 months followed by standard clinical care for 18 months was conducted in 357 children with anisometropic, strabismic, or combined amblyopia (20/40-20/100) whose ages ranged from 3 to younger than 7 years at enrollment. Ocular alignment was evaluated at enrollment and after 2 years of follow-up. RESULTS: At enrollment when tested at distance fixation, 161 (45%) children were orthotropic, 91 (25%) had a microtropia (1-8 Delta), and 105 (29%) had a heterotropia >8 Delta. Of the 161 patients with no strabismus, similar proportions of patients initially assigned to the patching and atropine groups developed new strabismus by 2 years (18% vs. 16%, P = 0.84). Of these cases of new strabismus, only 2 patients in the patching group and 3 patients in the atropine group developed a deviation that was greater than 8 Delta. Microtropia at enrollment progressed to a deviation greater than 8 Delta with similar frequency in both treatment groups (13% vs. 15%, P = 1.00). Of the 105 patients with strabismus greater than 8 Delta at enrollment, 13% of those in the patching group and 16% of those in the atropine group improved to orthotropia without strabismus surgery. Strabismus surgery was performed in 32 patients during the 2-year study period. CONCLUSIONS: Patients who had amblyopia treatment with patching or atropine for 6 months followed by standard clinical care were found to have similar rates of deterioration and improvement of ocular alignment. When parents begin amblyopia treatment for children without strabismus, they should be warned of the possibility of development of strabismus, although it is most often a small angle deviation. Strabismus resolved after amblyopia therapy in some cases.     

A randomized controlled trial of unilateral strabismic and mixed amblyopia using occlusion dose monitors to record compliance

PURPOSE: To investigate compliance with patching therapy and the dose-effect relationship in occlusion therapy in amblyopia by recording the effective patching time using occlusion dose monitors (ODMs). METHODS: Fifty-two children with strabismic or mixed amblyopia (Snellen equivalent, 6/12-6/48) were given optimal refractive correction and randomly allocated for 12 weeks into three treatment groups: group 1, no patching; group 2, prescribed patching for 3 hours; and group 3, prescribed patching for 6 hours. The effective time of occlusion was monitored with ODMs continuously. Visual acuity (VA) was measured every 3 weeks with LogMAR (logarithm of the minimum angle of resolution) Crowded Tests. RESULTS: In the 3- and 6-hour groups, mean (SD) compliance was 57.5% (30.8%) and 41.2% (30.9%), respectively, and mean effective patching time per day was 1 hour 43 minutes (55 minutes) and 2 hours 33 minutes (1 hour 52 minutes), respectively. The mean (SD) improvement in logMAR VA of amblyopic eyes was 0.24 (0.17), 0.29 (0.14), and 0.34 (0.19) in groups 1, 2, and 3, respectively. There was no significant difference in compliance with the prescribed patching between the 3- and 6-hour groups. VA outcomes in the 3- and 6-hour groups were not significantly better than 0-hour patching. However, the VA of patients with eyes effectively patched for more than 3 hours improved significantly. A dose-effect relationship was observed. Age at treatment did not influence the visual outcome. CONCLUSIONS: Poor compliance with prescribed occlusion explains discrepancies in previous studies. No differences in the effect between the different prescribed patching periods were found. The dose-effect relationship observed should encourage development of methods such as educational intervention to improve visual outcome by increasing effective patching time.