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A comparison of atropine and patching treatments for moderate amblyopia by patient age, cause of amblyopia, depth of amblyopia, and other factors.

OBJECTIVE: To assess whether the relative treatment effect of patching compared with atropine for moderate amblyopia varies according to patient age, cause of amblyopia or depth of amblyopia, and initial number of patching hours prescribed. DESIGN: Multicenter, randomized clinical trial. PARTICIPANTS: Four hundred nineteen children younger than 7 years of age with amblyopia in the range of 20/40 to 20/100. METHODS: Patients were assigned randomly to receive treatment with either patching or atropine and followed up for 6 months. PRIMARY OUTCOME MEASURE: Single-surrounded HOTV optotype visual acuity in the amblyopic eye after 6 months. RESULTS: Improvement in the amblyopic eye visual acuity was slightly greater in the patching group compared with the atropine group in all subgroups based on patient characteristics. The relative treatment effect did not vary with age (P = 0.84), cause of amblyopia (P = 0.68), or baseline amblyopic eye acuity (P = 0.59). Patients with acuity of 20/80 to 20/100 who were prescribed 10 or more hours a day of patching showed a more rapid improvement in acuity than did patients prescribed a lesser amount of patching (P = 0.01) or than did patients in the atropine group (P < 0.001), but by 6 months, the differences were not significant (P = 0.47 and 0.15, respectively). CONCLUSIONS: A beneficial effect of both patching and atropine is present throughout the age range of 3 to younger than 7 years old and the acuity range of 20/40 to 20/100. Patients with acuity of 20/80 to 20/100 improve faster when a greater number of hours of patching is prescribed, but by 6 months, the amount of improvement is not related to the number of hours of patching initially prescribed.

Age Factors↗

The therapy of amblyopia: an analysis comparing the results of amblyopia therapy utilizing two pooled data sets.

CONTEXT: We previously presented the results of an original pooled data set of 961 amblyopic patients who underwent patching therapy for amblyopia from 1965 to 1994 (study group 1). Three types of amblyopia were considered: anisometropic, anisometropic-strabismic, and strabismic. Analysis of this group's success was related to the age at which therapy was initiated, the type of amblyopia, and the depth of visual loss before treatment was begun. The purpose of the current study is to test the validity of these findings on a second group of 961 amblyopes employing the data set used by Woodruff and associates in their publications (study group 2). These 2 data sets, after adjustment to conform to the definitions of age, amblyopia, anisometropia, and similar items utilized in common between the 2 study groups, will be compared for the risk factors predictive of successful occlusion therapy. OUTCOME: As in the previous study, the success of occlusion therapy is defined as a visual acuity of 20/40 or better at the end of treatment. RESULTS: Success by the 20/40 criteria was achieved in 73.7% in study group 1 and in 59.9% in study group 2. By category, the rate of success in study group 1 was 77.2% in strabismic amblyopia, 67.2% in anisometropic-strabismic amblyopia, and 66.0% in anisometropic amblyopia. In study group 2, success was 61.2% in strabismic amblyopia, 51.2% in anisometropic-strabismic amblyopia, and 63.0% in anisometropic amblyopia. Study group 1 univariate analysis related success in each group to the age at which therapy was initiated, the type of amblyopia, and the depth of visual loss before treatment in each group. In study group 2, univariate analysis related success of occlusion therapy to age and the depth of visual loss before treatment. Type of amblyopia was not related to outcome success in this group. When the 2 data sets were pooled, the risk factors for success were age and depth of visual loss at onset of treatment. CONCLUSIONS: Factors that appeared closely related to a successful outcome of patching therapy were patient age and depth of visual loss before treatment. These conclusions further support the value of early detection and screening for amblyopia, its prevention, where possible, and its adequate and vigorous treatment when it is detected and diagnosed.

Amblyopia↗

The therapy of amblyopia: an analysis of the results of amblyopia therapy utilizing the pooled data of published studies.

CONTEXT: Although the treatment of amblyopia with occlusion has changed little over the past 3 centuries, there is little agreement about which regimes are most effective and for what reasons. OBJECTIVE: To determine the outcome of occlusion therapy in patients with anisometropic, strabismic, and strabismic-anisometropic amblyopia employing the raw data from 961 patients reported in 23 studies published between 1965 and 1994. DESIGN: Analysis of the published literature on amblyopia therapy results during the above interval, utilizing primary data obtained from the authors of these articles or tables published in the articles detailing individual patient outcomes. PARTICIPANTS: 961 amblyopic patients, participants in 23 studies, undergoing patching therapy for amblyopia from 1965 to 1994 with anisometropia, strabismus, or anisometropia-strabismus. MAIN OUTCOMES: In the pooled data set, success of occlusion therapy was defined as visual acuity of 20/40 at the end of treatment. RESULTS: Success by the 20/40 criteria was achieved in 512 of 689 (74.3%) patients. By category, 312 of 402 (77.6%) were successful in strabismic amblyopia, 44 of 75 (58.7%) in strabismic-anisometropic amblyopia, and 72 of 108 (66.7%) in anisometropic amblyopia. Success was not related to the duration of occlusion therapy, type of occlusion used, accompanying refractive error, patient's sex, or eye. Univariate analyses showed that success was related to the age at which therapy was initiated; the type of amblyopia; the depth of visual loss before treatment for the anisometropic patients and the strabismic patients, but not for the anisometropic-strabismic patients; and the difference in spherical equivalents between eyes, for the anisometropic patients. Logistic/linear regression revealed that 3 were independent predictors of a successful outcome of amblyopia therapy. CONCLUSIONS: Factors that appear most closely related to a successful outcome are age, type of amblyopia, and depth of visual loss before treatment. These may be related to factors, as yet undetermined in the pathogenesis of amblyopia. With present emphasis on the value of screening and prevention and the development of new screening tools, such a look at the results of amblyopia therapy in a large population seems indicated.

Adolescent↗

BVAT distance vs. near stereopsis screening of strabismus, strabismic amblyopia and refractive amblyopia; a prospective study of 68 patients.

PURPOSE: Although there have been studies in the past of the difference between distance and near stereopsis in intermittent exotropia, no such comparisons have been studied and/or reported for other forms of strabismus, nor for strabismic functional amblyopia, or for refractive functional amblyopia. METHODS: The study was prospective: Sixty-eight consecutive patients, ages 6-76 years, with either childhood onset strabismus and no amblyopia, childhood onset strabismus and amblyopia, or refractive amblyopia and no strabismus, had their stereopsis measured. Distance stereopsis was determined on the Mentor BVAT with Random Dot E Test (global stereopsis) and the Circle Test (contour stereopsis). Near stereopsis was determined with the Circle Test of the Randot Stereotest. The data were tabulated and analyzed statistically. RESULTS: Of the 26 strabismus/no amblyopia cases, 14 (54%) appreciated distance stereopsis. Of these, 12/14 were intermittent, and other 2 who were constant had deviations of 8 PD or less. Only 4 of the 14 appreciated global stereopsis at distance (mean = 90 sec. of arc), but all 14 appreciated contour stereopsis at distance (mean = 125 sec. of arc). Of all 26, 21 (81%) had near stereopsis (mean = 137 sec. of arc). For the 21 strabismic amblyopes, only one appreciated global stereopsis at distance (120 sec of arc), and 2 (10%) contour stereopsis at distance (mean = 210 sec. of arc). These two and 4 others (total 29%) had near stereopsis (mean = 162 sec. of arc). For the 21 refractive amblyopes, 3 appreciated global stereopsis at distance (mean = 220 sec. of arc), 11 in all, (52%) contour stereopsis at distance (mean = 121 sec. of arc) and 20 (95%) had near stereopsis (mean = 78 sec. of arc). The percentages of patients in all categories capable of appreciating distance stereopsis were "statistically significantly" (P<.05) or clinically/medically significantly different from (less than) the percentages having near stereopsis. CONCLUSIONS: distance stereopsis is more likely to be reduced or absent than near stereopsis in strabismus, strabismic amblyopia and refractive amblyopia and thus appears to be more sensitive to, and better screening for, binocular vision disorders and a stronger and better outcome standard for treatment of binocular vision disorders than near stereopsis.

Adolescent↗

Factors affecting long term results of successfully treated amblyopia: initial visual acuity and type of amblyopia.

AIMS: The study aimed to assess the effect of initial visual acuity and type of amblyopia on the long term results of successfully treated amblyopia. METHODS: The visual acuity of 94 patients, who had been successfully treated for unilateral amblyopia by occlusion of the good eye and followed up to the age of 9 years, was examined 6.4 years, on average, after cessation of treatment. Patients were divided into two groups according to the depth of amblyopia before occlusion therapy was started: those with visual acuity between 20/60 and 20/100 and those with visual acuity of 20/100 or worse. RESULTS: Deterioration of visual acuity was observed in 42% of patients in the first group and in 63% of patients in the second group. Their average deterioration, as measured by the Snellen chart, was 0.58 and 1.54 lines, respectively. The results were also assessed by the division of patients into three groups according to the type of amblyopia: strabismic, strabismic anisometropic, and anisometropic. Deterioration of visual acuity occurred in 46%, 79%, and 36% of patients in these three groups, with an average deterioration on the Snellen chart of 0.70, 2.04, and 0.64 lines, respectively. CONCLUSION: It is concluded that low initial visual acuity and strabismic anisometropic amblyopia are risk factors for deterioration of visual acuity in the long term, following the successful earlier treatment of eyes with amblyopia.

Adolescent↗

[The development of occlusion amblyopia following atropine therapy for strabismic amblyopia].

For the treatment of strabismic amblyopia the authors have used atropine in the sound eye under usual optical correction as soon as central fixation of the amblyopic eye is secured by means of proceeding occlusion therapy. Although there may be little effect of occlusion in atropine therapy, six children under five years of age developed amblyopia in their sound eyes. In every case, the first sign of developing amblyopia was the decrease of fixation ability in the sound eye in a binocular fixation test prior to the reduction of visual acuity. On the other hand, fixation ability of the originally amblyopic eye was reinforced more and more not only during atropinization but after its finish until deep amblyopia developed in the sound eye. In three cases, eccentric fixation occurred at 7, 9, and 17 weeks after atropinization. These facts suggest that occlusion amblyopia following atropine therapy is not the result of deprivation but is due to the reversal of the eye used for fixation. Strabismic amblyopia may have the tendency toward an alternation between fixation abilities of the two eyes and such a binocular sensory anomaly may cause strabismic amblyopia itself.

Amblyopia↗

Form-vision deprivation amblyopia and strabismic amblyopia.

The treatment program for form-vision deprivation and strabismic amblyopia currently followed in our orthoptic clinic is presented. In unilateral congenital cataract, a disease that causes form-vision deprivation amblyopia, good vision up to 20/20 can be obtained through surgery performed before the patient reaches 8 weeks of age, employing new surgical techniques such as lentectomy and vitrectomy, combined with early aphakic eye correction and occlusion of the healthy eye. In strabismic amblyopia, prevention and/or early treatment are very important, particularly in cases of unilateral infantile esotropia. Our success rate with occlusion therapy was 84.6% using a patch and 83.3% employing atropine cycloplegia. Occlusion therapy is monitored with the preferential looking technique to prevent the development of occlusion amblyopia. The visual prognosis for amblyopia due to unilateral congenital cataract and infantile strabismic amblyopia has been improved compared with previous reports. The prognosis for binocular function remains poor.

Age Factors↗

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.

Amblyopia↗

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

PURPOSE: To assess the course of the response to atropine treatment of moderate amblyopia and to assess factors predictive of the treatment response in children 3 years old to younger than 7 years old. DESIGN: Multicenter, randomized clinical trial comparing atropine and patching (one of the amblyopia treatment studies). METHODS: A total of 195 children 3 years old to younger than 7 years of age with amblyopia in the range of 20/40 to 20/100 from the atropine treatment arm of this trial were enrolled and included in this analysis. At baseline, daily topical atropine was prescribed for the sound eye. During follow-up, a plano spectacle lens was prescribed for the sound eye for patients whose amblyopia had not been successfully treated with atropine alone. 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: Mean visual acuity improved from baseline by 1.3 lines after 5 weeks of treatment, by 2.4 lines after 16 weeks, and by 2.8 lines at 6 months. Visual acuity of 20/30 or better and/or 3 or more lines of improvement from baseline was achieved by 75% of the patients. Improvement occurred over the entire range of baseline acuities (20/40 to 20/100) and was not related to patient age (P =.36). Among the 134 patients improving 3 or more lines from baseline, 7% achieved their maximum improvement by 5 weeks and 46% by 16 weeks. Among the 55 patients who did not respond adequately to atropine alone and were prescribed a plano lens for the sound eye, the mean improvement before the use of the plano lens was 1.0 lines, compared with 1.6 lines after prescribing the plano lens (P =.11). None of the demographic or clinical factors assessed was predictive of the response to treatment. A shift in fixation preference at/near from the atropinized sound eye to the amblyopic eye was not required for the amblyopic eye to improve; amblyopic eye acuity improved 3 or more lines in 29 (60%) of the 48 patients who were found to be using the atropinized sound eye on fixation preference testing. A 2 or more line decrease in sound eye visual acuity occurred more frequently when a plano lens was prescribed in addition to atropine (7 of 43, 16%) compared with treatment with atropine alone (4 of 123, 3%; P =.01). CONCLUSIONS: A beneficial effect of atropine is present throughout the age range of 3 years old to younger than 7 years old, and with an acuity range of 20/40 to 20/100. A shift in near fixation to the amblyopic eye is not essential for atropine to be effective in all cases. Sound eye acuity should be monitored when a plano spectacle lens is prescribed for the sound eye to augment the treatment effect of atropine.

Amblyopia↗

Amblyopia case reports--bilateral hypermetropic ametropic amblyopia.

Six patients are presented with ametropic amblyopia secondary to bilateral hypermetropia. Two patients had a strabismic amblyopia superimposed upon the ametropic amblyopia. All patients had a marked improvement in their visual acuity with the use of constant glass wear only. No associated ocular pathology was identified. It is the authors' belief that these patients are seen occasionally in general ophthalmologic practice. The diagnosis and treatment is straightforward; however, the diagnosis can be perplexing and unnecessary referrals and neuro-ophthalmologic investigation can ensue if this entity is not recognized.

Amblyopia↗

The tropical amblyopia syndrome (or tropical nutritional amblyopia) in the Mid-Western State of Nigeria.

One hundred and seven patients from the Mid-Western State of Nigeria with the tropical amblyopia syndrome are reported. Ninety-five patients (88.8%) had the amblyopia syndrome mainly; twelve patients (11.2%) had amblyopia and other manifestations of the tropical ataxic neuropathy. The young, aged 10-20 years, represented by sixty-six patients (61.8%), are predominantly affected by the uncomplicated syndrome. Thirteen patients (12.1%) showed muco-cutaneous evidence of avitaminosis. Fifty patients (46.7%) had temporal pallor of the optic discs, bilaterally, another fifty (46.7%) had normal discs, two (2.8%) showed pink discs. Generalized field constriction is the common field defect, though central or centro-caecal scotoma can occur. Red/green defect was present in seven patients. It is a disease of the poor or those living on a basic monotonous diet consisting mainly of cassava (mannihot) and its derivatives. It is a significant cause of defective vision in Mid-Western Nigeria.

Adolescent↗

Blue filter amblyopia treatment protocol for strabismic amblyopia: a prospective comparative study of 50 cases.

PURPOSE: Previous studies of monochromatic visual evoked potentials confirm the strong suppression of (the cortical representation of) paracentral retinal areas of functionally amblyopic eyes, by a flat response to a blue stimulus. A clinical trial stimulating these areas with blue light was encouraging, and justified a prospective comparison of this treatment with conventional classic treatment. SUBJECTS AND METHODS: In 50 strabismic children with amblyopia, the blue filter treatment protocol (flash stimulation with, and the wearing of, a blue filter during occlusion of the better eye for one hour daily) was compared with the classical treatment (full time total occlusion by patch) in a prospective matched and randomized study. Patients 3 to 7 years old without previous treatment and a visual acuity up to 0.3 were admitted to the study. Visual acuity and fixation behavior were used as the parameters of comparison. Visual Evoked Potentials by monochromatic flashes were also studied. Results of treatment were compared after 6 months. RESULTS: The visual acuity outcome for the blue filter treatment was "statistically significantly" better (p=0.005). The greatest improvement was seen in the subgroup of children with eccentric fixation (p=0.01). Fixation behavior also showed a better outcome from the blue filter treatment (p=0.05) favoring especially children between 3 and 5 years. In children of this age with a visual acuity better than 0.1 we found a very "statistically significant" difference between the two treatments (p=0.004). In children 3 to 5 years old with poorer visual acuity we also found a "statistically significant" difference in the two treatments (p=0.04). The interocular difference of amplitude on the Visual Evoked Potentials also demonstrated more improvement in children treated with the blue filter. This treatment improved especially the cortical response to blue flash stimulation, correlating to paracentral retinal areas. CONCLUSIONS: The blue filter treatment protocol provided better results for treating amblyopia than the conventional classic occlusion treatment method. We propose that stimulation of these paracentral retinal areas triggers a better disinhibition of a functionally amblyopic eye.

Amblyopia↗

[Disorders of eye movements in point fixation of the dominant eye in unilateral deprivation amblyopia, squint amblyopia and unilateral organ damage].

In four juvenile patients with unilateral deprivation amblyopia three types of involuntary eye movement were identified by simultaneous binocular infrared reflection oculography (IROG). During apparent steady-point fixation of the dominant eye three cases showed sinusoidal pendular movements (type 1) of the amblyopic eye mainly in a horizontal and slightly in a vertical direction, amplitude (A) 1 to 4 degrees, frequency (F) 0.25-0.4 Hz; only one patient had similar movements with smaller deviations even in the fixing eye. In three cases disturbed fixation of the dominant eye was found, a lateral drift (type 2) up to 3 degrees followed by slow correcting movement (F 0.05-0.1 Hz). At the same time there were disjugate movements of the amblyopic eye, the movements of the two eyes resulting in variations in squint angle of up to 6-7 degrees. These movements of the weaker eyes were clinically observed by Ohm (1958) and were termed pendular flutter to distinguish them from nystagmus. This paper presents the first objectively recorded curves of these movements, and differentiates them according to the various types of movement. Type 3 is a fine jerky or pendular nystagmus (A = max. 1 degree, F = 1.0-2.8 Hz), which was also present in three cases. Two patients had a combination of all three types of motility disturbance. Four cases with unilateral organ lesions, either congenital or acquired in early infancy, were observed and compared. All these cases showed excessive pendular flutter (type 1)--horizontal in the case of the fixing eye and horizontal and vertical in the case of the weaker eye.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗