***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The treatment of amblyopia is centuries old . A systematic description of occlusion therapy was provided by Leclerc ' in 1743 , and to this day the method has by and large remained unchanged . Although occlusion often leads to beneficial results , 23 there are cases where it is unacceptable to the child and frustrating for the parents . When occlusion has failed other methods have been tried . " Dazzling or after-image stimulation of the foveola requires active co-operation from the child and therefore is often applied in a very late stage of the visually immature period . The success rate is poor . Penalisation,8 another alternative , works best in cases of amblyopia combined with hyperopia and /or nystagmus . In one of their earlier papers Hubel and Wiesel9 showed that there are cell clusters in the visual cortex that only respond to rectangular stimuli with a specific orientation . Thus different clusters respond to different angles of orientation . This forms the basis of the latest addition to the amblyopia therapy arsenal -the CAM stimulator . In 1978 when Banks et al. ' ° " described the method and the instrument , reporting improvement in 38 of 40 cases , the method seemed very promising . This led us to initiate this study in which CAM treatment was compared with occlusion on equally large r and omly allocated groups . Since then others'2 13 have reported that CAM is not only as efficient as occlusion but also produces results sooner and therefore should be the treatment of choice In a controlled study , the amblyopic eye of a group of 12 patients was stimulated in accordance with the original method of Campbell et al. ( 1978 ) , using gratings , and a control group of 10 patients with black and white pictures . As in other controlled studies , no specific benefits ensued from the use of gratings . In both groups only slight visual improvements result ed , probably due to the repeated testing of visual acuity and nonspecific effects of short-term occlusion . A clear improvement in visual acuity and fixation behaviour was only observed after subsequent long-term occlusion OBJECTIVE To develop a question naire to assess the acceptability of  amblyopia treatment  and its effect on the child and family . METHODS A 20-item parental survey was developed and pilot tested on 64 subjects , aged 3 to 6 years , participating in the Amblyopia Treatment Study , a r and omized trial comparing patching and atropine as treatments for moderate amblyopia . The survey was administered after 4 weeks of treatment . A descriptive item analysis and an internal consistency reliability analysis were performed . RESULTS Nineteen of the 20 items demonstrated adequate variability as evidence d by the frequency distributions for item responses . Only 4 ( < 1 % ) of 1280 possible item responses were missing , one each by 4 different respondents . Factor analysis identified 3 treatment-related factors--"adverse effects , " " compliance , " and " social stigma "-- among 11 of the 20 items . The internal-consistency reliability alpha for the 5-item adverse effects subscale was 0.82 , the 4-item compliance subscale alpha was 0.81 , and the 2-item social stigma subscale alpha was 0.84 . CONCLUSIONS The Amblyopia Treatment Index appears to be a useful instrument for assessing the impact of amblyopia treatment in 3- to 6-year-old 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 Prospect i ve , r and omized 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 R and omization 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 BACKGROUND To plan a future r and omized clinical trial , we conducted a pilot study to determine whether children r and omized 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 r and omly 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 r and omized amblyopia treatment trial of patching with and without near activities is both feasible and desirable Abstract Objectives To test the efficacy of treatment for unilateral visual loss detected by preschool vision screening and the extent to which effectiveness varies with initial severity . Design R and omised controlled trial of full treatment with glasses and patching , if required , compared with glasses only or no treatment . Masked assessment of best corrected acuity after one year of follow up . Setting Eight UK eye departments . Participants 177 children aged 3 - 5 years with mild to moderate unilateral impairment of acuity ( 6/9 to 6/36 ) detected by screening . Results Children in the full and glasses treatment groups had incrementally better visual acuity at follow up than children who received no treatment , but the mean treatment effect between full and no treatment was equivalent to only one line on a Snellen chart ( 0.11 log units ; 95 % confidence interval 0.050 to 0.171 ; P < 0.0001 ) . The effects of treatment depended on initial acuity : full treatment showed a substantial effect in the moderate acuity group ( 6/36 to 6/18 at recruitment ) and no significant effect in the mild acuity group ( 6/9 to 6/12 at recruitment ) ( P = 0.006 for linear regression interaction term ) . For 64 children with moderate acuity loss the treatment effect was 0.20 log units , equivalent to one to two lines on a Snellen chart . When all children had received treatment , six months after the end of the trial , there was no significant difference in acuity between the groups . Conclusions Treatment is worth while in children with the poorest acuity , but in children with mild ( 6/9 to 6/12 ) unilateral acuity loss there was little benefit . Delay in treatment until the age of 5 did not seem to influence effectiveness Objectives To compare visual outcome in response to two prescribed rates of occlusion ( six hours a day and 12 hours a day ) . Design Unmasked r and omised trial . Setting Research clinics in two London hospitals . Participants 97 children with a confirmed diagnosis of amblyopia associated with strabismus , anisometropia , or both . Interventions : 18 week period of wearing glasses ( refractive adaptation ) followed by occlusion prescribed ( “ patching ” ) for six or 12 hours a day . Main outcome measures Visual acuity measured by logMAR letter recognition ; objective ly monitored rate of occlusion ( hours a day ) . Results The mean age of children at study entry was 5.6 ( SD 1.5 ) years . Ninety were eligible for occlusion but 10 dropped out in this phase , leaving 80 children who were r and omised to a prescribed dose rate of six ( n=40 ) or 12 ( n=40 ) hours a day . The mean change in visual acuity of the amblyopic eye was not significantly different ( P=0.64 ) between the two groups ( 0.26 ( 95 % confidence interval 0.21 to 0.31 ) log units in six hour group ; 0.24 ( 0.19 to 0.29 ) log units in 12 hour group ) . The mean dose rates ( hours a day ) actually received , however , were also not significantly different ( 4.2 ( 3.7 to 4.7 ) in six hour group v 6.2 ( 5.1 to 7.3 ) in 12 hour group ; P=0.06 ) . The visual outcome was similar for those children who received three to six hours a day or more than six to 12 hours a day , but significantly better than that in children who received less than three hours a day . Children aged under 4 required significantly less occlusion than older children . Visual outcome was not influenced by type of amblyopia . Conclusions Substantial ( six hours a day ) and maximal ( 12 hours a day ) prescribed occlusion results in similar visual outcome . On average , the occlusion dose received in the maximal group was only 50 % more than in the substantial group and in both groups was much less than that prescribed . Younger children required the least occlusion . Trials registration Clinical Trials NCT00274664 PURPOSE To determine the amount and time course of binocular visual acuity improvement during treatment of bilateral refractive amblyopia in children three to less than 10 years of age . DESIGN Prospect i ve , multicenter , noncomparative intervention . METHODS One hundred and thirteen children ( mean age , 5.1 years ) with previously untreated bilateral refractive amblyopia were enrolled at 27 community- and university-based sites and were provided with optimal spectacle correction . Bilateral refractive amblyopia was defined as 20/40 to 20/400 best-corrected binocular visual acuity in the presence of 4.00 diopters ( D ) or more of hypermetropia by spherical equivalent , 2.00 D or more of astigmatism , or both in each eye . Best-corrected binocular and monocular visual acuities were measured at baseline and at five , 13 , 26 , and 52 weeks . The primary study outcome was binocular acuity at one year . RESULTS Mean binocular visual acuity improved from 0.50 logarithm of the minimum angle of resolution ( logMAR ) units ( 20/63 ) at baseline to 0.11 logMAR units ( 20/25 ) at one year ( mean improvement , 3.9 lines ; 95 % confidence interval [ CI ] , 3.5 to 4.2 ) . Mean improvement at one year for the 84 children with baseline binocular acuity of 20/40 to 20/80 was 3.4 lines ( 95 % CI , 3.2 to 3.7 ) and for the 16 children with baseline binocular acuity of 20/100 to 20/320 was 6.3 lines ( 95 % CI , 5.1 to 7.5 ) . The cumulative probability of binocular visual acuity of 20/25 or better was 21 % at five weeks , 46 % at 13 weeks , 59 % at 26 weeks , and 74 % at 52 weeks . CONCLUSIONS Treatment of bilateral refractive amblyopia with spectacle correction improves binocular visual acuity in children three to less than 10 years of age , with most improving to 20/25 or better within one year BACKGROUND / AIMS The study of occlusion efficacy in amblyopia has been hampered by the use of non-logMAR acuity tests and a failure to assess threshold acuity for both eyes . These issues are addressed in the current study which compares the effect of spectacles alone and spectacles in combination with occlusion , with the use of the logMAR crowded test . METHODS Changes in uniocular and interocular acuity differences were compared for two age matched groups of previously untreated children with strabismic amblyopia : one compliant with spectacles only ( n = 17 , mean 6.2 ( SD 2.5 ) years ) and the other with spectacles and occlusion ( n = 69 , mean 5.1 ( 1 ) years ) over a 1 year period . Changes in logMAR acuity were also analysed for a larger occluded group ( n = 
    Output:
    
In some cases of unilateral refractive amblyopia it appears that there is a treatment benefit from refractive correction alone .
Where amblyopia persists there is evidence that adding occlusion further improves vision .
Partial occlusion appears to have the same treatment effect as glasses alone when started simultaneously for the treatment of unilateral refractive amblyopia .