Long-term changes in visual acuity and refractive error in amblyopes.

PURPOSE: To report long-term changes in visual acuity and refractive error for strabismic, anisometropic, and isoametropic amblyopes. METHODS: Records of patients with strabismic amblyopia, anisometropic amblyopia, and isoametropic amblyopia who were treated from 1983 to 1993 were reviewed. Excluded were patients having ocular or neurological diseases, developmental delay, and follow-up <4 years after treatment cessation. Data included best-correctable visual acuity and spherical equivalent refractive error of the amblyopic and the nonamblyopic eye at pretreatment, posttreatment, and long-term follow-up. RESULTS: Records for 61 patients met the inclusion criteria. For strabismic amblyopia (n = 22), mean visual acuity in amblyopic and nonamblyopic eyes improved 0.36 and 0.05 logarithm of the minimum angle of resolution (logMAR) units after a mean treatment time of 1 year. At long-term follow-up (mean = 9.3 years after treatment), visual acuity in the amblyopic eye regressed 0.09 logMAR and visual acuity in the nonamblyopic eye improved 0.10 logMAR units. For anisometropic amblyopia (n = 26), mean visual acuity in amblyopic and nonamblyopic eyes improved 0.30 and 0.02 logMAR units, respectively, after a mean treatment period of 1.1 year. At the long-term follow-up visit (mean = 7.1 years after treatment), visual acuity in the amblyopic eye regressed 0.09 logMAR unit and in the nonamblyopic eye improved 0.03 logMAR unit. Repeated-measures analysis of variance showed no significant effect of type of amblyopia on visual acuity of the amblyopic eye and a significant effect of visit due to treatment but not regression. The changes in visual acuity in the nonamblyopic eye from the pretreatment to the follow-up visit were significant and interacted with type, the changes being larger in strabismic amblyopia. For strabismic amblyopia, the mean refractive error in amblyopic and nonamblyopic eyes changed from +2.15 D and +1.85 D, respectively, initially to +0.45 D and +0.58 D, respectively, at the follow-up visit. For anisometropic amblyopia, the mean refractive error in amblyopic and nonamblyopic eyes changed from +1.04 D and +0.12 D, respectively, initially to +0.23 D and -0.94 D, respectively, at the follow-up visit. The effect of visit on amblyopic and nonamblyopic refractive errors was significant. For isoametropic amblyopia (n = 13), visual acuity in both right and left eyes initially was 0.39 logMAR unit and improved to 0.14 logMAR unit in each eye after a mean follow-up of 8.9 years. Refractive error in the right and the left eyes changed from -1.22 D and -1.14 D, respectively, to -2.68 D and -2.56 D, respectively, at follow-up. These differences were all significant. CONCLUSIONS: After treatment and with long-term follow up, visual acuity regresses but not significantly in the amblyopic eye in strabismic amblyopia and anisometropic amblyopia. At the same time, visual acuity in the nonamblyopic eye improves slightly. Visual acuity also improves significantly over time in isoametropic amblyopia. The refractive error of both amblyopic and nonamblyopic eyes tends to show a myopic shift regardless of the type of amblyopia.     

The contrast sensitivity function and childhood amblyopia

We measured contrast sensitivity function and visual acuity in both eyes of strabismic and anisometropic amblyopic patients. There was a linear relationship between contrast sensitivity function and visual acuity in the amblyopic eye. As visual acuity decreased, the contrast sensitivity function decreased along the contrast sensitivity axis, and peak sensitivity shifted to lower spatial frequencies. After patching therapy, when visual acuity reached 20/20 in each eye, suggesting that the amblyopia was cured, there continued to be statistically significant difference in the contrast sensitivity functions between the eyes. The contrast sensitivity function from the previously amblyopic eye was depressed compared to the nonamblyopic eye. A comparison between patients with strabismic and anisometropic amblyopia showed that, when matched for visual acuity, the contrast sensitivity functions were similar for both the nonamblyopic and amblyopic eyes. However, a large difference was found between the amblyopic and nonamblyopic eyes of each group.     

Efficiency of occlusion therapy for management of amblyopia in older children

PURPOSE: To analyse results of full time occlusion therapy for amblyopia in children older than 6 years. MATERIALS AND METHODS: This was a retrospective consecutive case series analysis of children treated for amblyopia at a tertiary care center. All children received full time occlusion (FTO) for the dominant eye. RESULTS: Eighty-eight children older than 6 years at the time of initiation of therapy were included. Age at initiation of therapy ranged from 6 to 20 years (9.45 +/- 3.11 years). Forty-two children (47.7%) had strabismic amblyopia, 37 (42.0%) had anisometropic amblyopia and 9 (10.2%) had a combination of strabismic and anisometropic amblyopia. Eighty out of 88 eyes (90.0%) had improvement in visual acuity following FTO. Visual acuity (VA) improved from 0.82 +/- 0.34 at presentation to 0.42 +/- 0.34 (P < 0.001) after FTO. In children with strabismic amblyopia, VA improved from 0.81 +/- 0.42 to 0.42 +/- 0.39 (P <0.001). In children with anisometropic amblyopia, visual acuity of the amblyopic eye improved fron 0.82 +/- 0.24 to 0.36 +/- 0.29 (P< 0.001) following FTO. Out of 13 children older than 12 years, only 6 children (46.1%) had improvement in VA. Mean follow-up after complete stoppage of occlusion was 8.37 +/- 1.78 months. CONCLUSION: Occlusion therapy yields favorable results in strabismic and/or anisometropic amblyopia, even when initiated for the first time after 6 years of age. After 12 years of age, some children may still respond to occlusion of the dominant eye.     

Evaluation of visual acuity in a historical cohort of 137 patients treated for amblyopia by occlusion 30-35 years ago

BACKGROUND: Opinions differ on the course of the visual acuity in the amblyopic eye after cessation of occlusion therapy. This study evaluated visual acuity in a historical cohort treated for amblyopia with occlusion therapy 30-35 years ago. MATERIALS AND METHODS: Between 1968 and 1975, 1250 patients had been treated by the orthoptist in the Waterland Hospital in Purmerend, The Netherlands. Of these, 471 received occlusion treatment for amblyopia (prevalence 5.0%, after comparison with the local birth rate). We were able to contact 203 of these patients, 137 were orthoptically re-examined in 2003. We correlated the current visual acuity with the cause of amblyopia, the age at start and end of treatment, the visual acuity at start and end of treatment, fixation, binocular vision and refractive errors. RESULTS: Mean age at the start of treatment was 5.4 +/- 1.9 years, 7.4 +/- 1.7 years at the end and 37 +/- 2.7 years at follow-up. Current visual acuity in the amblyopic eye was correlated with a low visual acuity at the start (p < 0.0001) and end (p < 0.0001) of occlusion therapy, an eccentric fixation (p < 0.0001), and the cause of amblyopia (p = 0.005). At the end of the treatment, patients with a strabismic amblyopia (n = 98) had a visual acuity in the amblyopic eye of 0.29 logMAR +/- 0.3, and in 2003 0.27 +/- 0.3 logMAR. In patients with an anisometropic amblyopia (> 1 D, n = 16) visual acuity had decreased from 0.17 +/- 0.23 logMAR to 0.21 logMAR +/- 0.23. In patients with both strabismic and anisometropic amblyopia (n = 23), visual acuity had decreased from 0.52 logMAR +/- 0.54 to 0.65 logMAR +/- 0.54. Overall, acuity had decreased in 54 patients (39%) after cessation of treatment. Of these, 18 patients had an acuity decrease to less than 50% of their acuity at the end of treatment. In 15 of these 18 patients anisohypermetropia had increased. CONCLUSIONS: A decrease in visual acuity after cessation of occlusion therapy occurred in patients with a combined cause of amblyopia or with an increase in anisohypermetropia.     

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.     

A pilot study of children with amblyopia treated by the gratings method.

A total of 6 patients, 2 with anisometropic, 2 with strabismic and anisometropic, and 2 with strabismic amblyopia treated with the 'gratings method' showed more than 2 lines of improvement in linear visual acuity. Patient attention and interest and repeated testing of the visual acuity were uncontrolled factors in this study. Moreover, the detailed visual tasks performed by the amblyopic eye may in themselves be the reason for improvement. Clearly a careful study which controls these possibilities is needed before a claim can be made that the 'gratings' per se offer an improved method of treatment of amblyopia.     

CSF interocular interactions in childhood ambylopia

Contrast sensitivity functions (CSF's) were measured in the amblyopic and dominant eyes of 17 strabismic and 28 anisometropic children and in 19 similar age normal controls. A three-alternative forced-choice procedure was used to measure CSF's with the VCTS 6500. The results revealed reduced contrast sensitivity (CS) in both the amblyopic and dominant eyes of strabismic and anisometropic amblyopes compared to normal controls. Statistically significant intereye correlations of CS at each spatial frequency were found in all groups and in the presence of deep amblyopia, suggesting continued interocular interactions and binocularity. A separate longitudinal study of 7 of the amblyopes showed that, during the course of occlusion therapy, both the amblyopic and the dominant eyes improved in CSF. The results suggest that the amblyopic eye may influence CS in the dominant eye through interocular interactions. This process may serve to minimize CSF differences between the eyes and maximize binocular vision.     

传统弱视治疗方法联合视功能训练治疗远视性屈光参差性弱视的疗效

目的　评价传统弱视治疗方法联合视功能训练治疗远视性屈光参差性弱视的疗效。方法　收集2016年3月至2017年5月就诊于天津市眼科医院弱视训练室的50例远视性屈光参差性弱视患者,年龄（7.57±2.65）岁。所有患者均排除其他眼部疾病、危险因素和全身性疾病。在屈光矫正、遮盖健眼的基础上对弱视眼进行治疗,分析治疗前后的视力、立体视变化情况。结果　根据筛选最终纳入31例远视性屈光参差性弱视患者,其中轻度弱视10例,中度弱视15例,重度弱视6例。31例患儿治疗前及治疗后3个月、6个月视力差异有统计学意义（F=48.591,P=0.000）;中、重度弱视组治疗前后3个时间点差异均有统计学意义,轻度弱视组治疗后与治疗前视力相比,差异有统计学意义,但治疗后6个月与治疗后3个月视力相比差异无统计学意义（P=0.223）。轻度弱视组与中、重度弱视组治疗后视力进步情况差异均有统计学意义（χ²=6.005,P=0.022;χ²=5.760,P=0.026）;治疗后立体视比治疗前明显提高,与视力呈负相关（r=-0.537,P=0.002;r=-0.885,P=0.000）。结论　传统弱视治疗方法联合视功能训练不仅可以提高远视性屈光参差性弱视患者视力,而且有助于双眼视功能的恢复。     

The effect of increasing doses of levodopa on children with strabismic amblyopia

PURPOSE: The purpose of this study was to determine the efficacy and tolerance of a levodopa/carbidopa combination and to test its dose-effect response when combined with occlusion therapy for children with amblyopia. METHODS: A 1-week randomized, double-blind, parallel, and placebo-controlled study was performed with 78 children with amblyopia aged between 7 and 17 years. Children who weighed less than 40 kg were randomly assigned to receive 5, 10, or 20 mg of levodopa or placebo (3 times a day), and those who weighed 40 kg or more were randomly assigned to receive 10, 20, or 40 mg of levodopa or placebo. Subjects were instructed to occlude the dominant eye (3 h/d). Snellen visual acuity was measured at baseline and at 2 hours after ingestion of the last capsule. Compliance with occlusion and capsule consumption was verified by a questionnaire and counting capsules. Adverse effects were checked with a physical examination and a questionnaire. RESULTS: From baseline to the follow-up test trial, the improvement in the logarithm of the Snellen fraction was 0.05+/-0.11 in the placebo group, 0.18 +/-0.21 in group 1, 0.08+/-0.11 in group II, and 0.16+/-0.15 in group III (P = .031). Visual acuity improved from 0.59 to 0.45 in the levodopa/carbidopa group and from 0.69 to 0.63 in the control group (P = .023). The compliance with occlusion was similar in all groups. No one complained of adverse side effects. CONCLUSION: Levodopa, at an average dose of 0.51 mg/kg per day, is well tolerated and produces a clinical and statistically significant short-term improvement of visual acuity in children with amblyopia.     

屈光不正性、屈光参差性及斜视性弱视的位置辨别比较

目的比较屈光不正性、屈光参差性及斜视性弱视患者的位置辨别功能差异以及单眼弱视双眼间位置辨别差异。方法选取在广西视光中心就诊的139例(237眼)弱视患者,按弱视类型分为屈光不正性弱视组40例(80眼)、屈光参差性弱视组61例(82眼)、斜视性弱视组38例(75眼),检测3组弱视位置辨别功能并进行比较分析。结果 3组弱视位置辨别功能检测结果均集中在2～4级之间,中位数均为3级,3组位置辨别功能结果比较,差异无统计学意义(Hc=0.530,P>0.05)。单眼弱视双眼位置辨别功能比较,差异无统计学意义(MH=1.837,P>0.05)。单眼弱视眼与双眼弱视眼位置辨别功能比较,差异无统计学意义(Z=-0.588,P>0.05)。结论屈光不正性、屈光参差性及斜视性弱视儿童位置辨别功能不存在差异,单眼弱视双眼位置辨别功能无差异,单眼弱视眼与双眼弱视眼位置辨别功能相似。     

部分遮盖法治疗大龄儿童弱视的疗效分析

目的 比较每天全遮盖健眼不同时间治疗7～12岁单眼弱视儿童的疗效.方法 对84例诊断为屈光参差性、斜视性或混合性单眼弱视的7～12岁儿童采用部分时间全遮盖健眼,随机分为每天遮盖2 h组、4 h组和6 h组.4周复查1次,记录视力及对应的logMAR值.连续随访6个月.结果每天遮盖2、4和6 h组,治疗6个月后视力提高分别为:0.17±0.09、0.25±0.12及0.30±0.13(LogMAR值),三组间差异有统计学意义(P<0.01).遮盖4 h和6 h组间视力提高,差异无统计学意义(P>0.05),但与2 h组间差异均有统计学意义(P<0.01).各类型弱视视力提高差异无统计学意义(P>0.05).结论 对于7～12岁单眼弱视儿童,每天全遮盖健眼2～6 h均能改善视力,但遮盖4 h及6 h较2 h能更有效地提高视力.     

Differential changes of magnocellular and parvocellular visual function in early- and late-onset strabismic amblyopia

PURPOSE: Studies in nonhuman primates show that monocular visual deprivation starting at different ages has different effects on cells in the parvocellular and magnocellular laminae of the lateral geniculate nucleus. The present study used color and luminance contrast sensitivity (CS) measurements to look for differences in parvocellular- and magnocellular-related visual function in human subjects with strabismic amblyopia. METHODS: Fifteen subjects with early- and 14 with late-onset strabismic amblyopia and similar ranges of visual acuity were studied, together with 15 subjects with normal vision. Contrast sensitivities were measured to an equiluminant (L-M cone-modulated) grating with slow onset and an achromatic (L+M cone-modulated) 0.8-cpd grating with rapid onset using an adaptive METHOD: RESULTS: Luminance and color CS were lower in the amblyopic eyes than in the fellow eyes of all amblyopes. For luminance CS, this was due both to an increase in sensitivity of the fellow eye and to a reduction in sensitivity in the amblyopic eye. Color CS was greatly reduced in the amblyopic and fellow eyes of subjects with strabismic amblyopia of early- and late onset compared with subjects with normal vision. The reduction in color CS compared with luminance CS was significantly greater in eyes with late- rather than early-onset amblyopia. CONCLUSIONS: Parvocellular and magnocellular function are differentially affected in the amblyopic and fellow eyes of subjects with strabismic amblyopia. The difference is more marked in late-onset amblyopia than in early-onset amblyopia.     

Visual evoked potential importance in the complex mechanism of amblyopia

To compare the visual evoked potential (VEP) responses of amblyopic eyes with VEP responses of sound eyes in amblyopic children. A study of 65 amblyopic children with pattern-reversal VEPs elicited by checkerboard stimuli with large, medium and small checks. The children were classified into three groups: Group A, 22 children with anisometropic amblyopia; Group B, 16 children with exotropic strabismic amblyopia; and Group C, 27 children with esotropic strabismic amblyopia. Visual acuity (VA) was significantly worse in the amblyopic eye as compared to the sound eye. However, no statistically significant difference was found between the amblyopic and sound eye of amblyopic children in the three groups for VEP P1 amplitude and latencies for any check sizes. VEP is a very important tool in understanding the complex amblyopic mechanism. Although the sound eye has superior VA, the absence of differences in VEP P1 amplitudes and latencies demonstrate the functional abnormality of the eye considered ‘good’. More studies are necessary to explain why the sound eye in amblyopic children cannot be considered completely normal. Special attention should therefore be paid to amblyopic treatment, as patching can have a negative effect on the sound eye.     

Comparative efficacy of penalization methods in moderate to mild amblyopia

PURPOSE: To compare the efficacy and sensory outcome of pharmacologic and optical penalization in the treatment of moderate to mild amblyopia. DESIGN: Randomized clinical trial. METHODS: In an institutional setting, two- to 10-year-old children with strabismic or anisometropic amblyopia (visual acuity in the amblyopic eye at least 20/60) who were cooperative to measure visual acuity using the logarithm of the minimum angle of resolution (logMAR) crowded Glasgow acuity cards were randomized into two groups of therapy (n=35 in each group), 1% atropine, and optical penalization with positive lenses, after stratification by cause of amblyopia. Visual acuity was tested by the logMAR crowded Glasgow acuity cards, after retinoscopic refraction, and deviation angle were measured by the simultaneous prism and cover or Krimsky test. Stereoacuity was determined using the Titmus fly test and Randot preschool or Randot circles stereoacuity test. Change in visual acuity of the amblyopic eye and in interocular difference of visual acuity after six months of amblyopia therapy was the main outcome measure; stereoacuity at six months of therapy was a secondary outcome measure. RESULTS: Thirty-one and 32 children completed the outcome examination in the atropine and optical penalization group, respectively. Average improvement in visual acuity of the amblyopic eye was larger in the atropine than in the optical penalization group (3.4 and 1.8 logMAR lines, respectively), as well as average improvement in interocular difference of visual acuity (2.8 and 1.3 logMAR lines, respectively). Better stereoacuity, but nonsignificantly different, was detected in the atropine group. CONCLUSIONS: Atropine penalization may be considered more effective than optical penalization with positive lenses.     

The effect of glare upon visual performance in keratoconus

Besides a loss in resolution acuity, amblyopia results in deficits in a number of visual functions in the amblyopic eye. We describe impairment in oscillatory movement displacement thresholds (OMDT) in childhood amblyopia. 50 subjects (aged 74 ± 16 months) with strabismic, anisometropic or mixed aetiology amblyopia were compared to a group of 24 age-matched controls. Thresholds were demonstrated to be in the hyperacuity range and were not related to the visual acuity. OMDT was significantly reduced in the amblyopic eye compared to the dominant and control eyes ( P < 0.05) only when no stereoscopic responses were demonstrated. When gross stereopsis was present, thresholds for the amblyopic eyes were comparable with both the dominant and control eyes. The results are discussed in terms of binocular competition and developmental anomaly.     

Electrophysiological and psychophysical differences between early- and late-onset strabismic amblyopia

PURPOSE: To compare visual evoked potentials (VEPs) and contrast sensitivity in adults with early- or late-onset strabismic amblyopia. METHODS: Twelve adults with early- and 12 with late-onset strabismic amblyopia with similar ranges of visual acuity were studied. Pattern-onset VEPs to 30-minute checks were recorded at a range of contrast levels. Contrast sensitivity (CS) was measured at 3.2 cyc/deg using a two-alternative, forced-choice staircase method. RESULTS: There was no significant difference in VEP CII latency or amplitude between amblyopic and fellow eyes across all contrast levels for the early-onset group, but in the late-onset group, CII latencies were significantly longer and amplitudes smaller in the amblyopic eye. CII responses in both amblyopic and fellow eyes of the early-onset amblyopes were of significantly shorter latency and smaller amplitude than normal. In the late-onset group the CII responses from the amblyopic eye were of significantly increased latency and reduced amplitude compared with normal, whereas latency and amplitude of fellow eye responses did not differ significantly from normal. Late-onset amblyopes showed reduced CS across the central field for the amblyopic eye, but increased CS for the fellow eye compared with normal. In the early-onset group, central CS did not differ between amblyopic and fellow eyes or from normal. CONCLUSIONS: There are significant differences in the electrophysiological and psychophysical characteristics of adults with early- and late-onset strabismic amblyopia.     

Investigation of visual field defects in strabismic and anisometropic amblyopes with the Octopus Program G1

Using the Octopus G1 program, we investigated the visual fields of amblyopic and healthy contralateral eyes in 21 patients with strabismic amblyopia and 14 patients with anisometropic amblyopia. All subjects had a visual acuity of 0.7-0.06. A central scotoma was detected in 85.7% of the patients with strabismic amblyopia and in 79% of those with anisometropic amblyopia. The mean maximal depth of central scotomas in subjects with strabismic amblyopia was 6.81 ± 4.74 dB (mean ± SD); in those with anisometropic amblyopia, it was 6.64 ± 4.34 dB. This difference was statistically not significant. However, in patients with anisometropic amblyopia, the visual field indices MD (mean defect) and CLV (corrected loss variation) were significantly higher than in those with strabismic amblyopia (P < 0.05 vsP < 0.05); this was predominantly due to additional flat defects that occurred paracentrally and peripherally in subjects with anisometropic amblyopia. In both groups of patients, we found a significant negative correlation between visual acuity, on the one hand, and the maximal depth of the scotomas and the visual field indices (MD and CLV), on the other.     

Determination of optical penalization by vectographic fixation reversal

Optical penalization for distance is a useful alternative to occlusion for treating amblyopia, and as maintenance therapy following occlusion. It is particularly useful in cases of patching noncompliance. The major key to patient acceptance is choosing the minimal amount of penalization necessary, while still ensuring that the patient actually switches fixation to the amblyopic eye. We have found the vectographic letter slide reliable for identifying the fixing eye for distance vision. Thirty-four patients were treated for anisometropic or strabismic amblyopia with distance optical penalization without the use of cycloplegic agents. Twenty-two patients had improvement of their visual acuity, and 10 patients remained the same during an average follow-up period of 22.5 months. The average visual acuity improved from 20/40 to 20/32. The dominant eye required an average of only +1.25 diopters of fogging for the patient to switch fixation to the amblyopic eye, significantly less than the arbitrary +3.00 diopters advocated by some clinicians.     

Efficacy of occlusion treatment in amblyopia and clinical risk factors affecting the results of treatment

PURPOSE: To evaluate the factors influencing visual outcome in strabismic, strabismic-anisometropic and anisometropic amblyopia following occlusion treatment. METHODS: Records of 128 pediatric patients who had been treated for amblyopia by occlusion of the fellow eye between March 1992 and March 2003 were reviewed retrospectively. Age and level of visual acuity at initiation of treatment, occlusion time (full-time, part-time or minimal) and type of amblyopia were analyzed for the effect on visual outcome. RESULTS: The mean age of the patients was 5.69 +/- 2.01 years (3 to 12 years). Mean follow-up time was 3 years 2 months (6 months to 10 years). Mean visual acuity improvements were similar for the subtypes of amblyopia (strabismic amblyopia 0.38 +/- 0.29 logMAR units, strabismic-anisometropic amblyopia 0.46 +/- 0.40 logMAR units, anisometropic amblyopia 0.35 +/- 0.24 logMAR units). Level of initial visual acuity, age at initiation of treatment and type of occlusion correlated with the final visual acuity (p = 0.000, p = 0.035, p = 0.012, respectively). When the analysis was performed according to the subtypes of amblyopia, initial visual acuity was the only factor associated with the final visual acuity in all types of amblyopia (p < 0.05). CONCLUSION: The level of initial visual acuity is the most significant factor determining the success of treatment in amblyopia.     

Amblyopia in 4-year-old children treated with grating stimulation and full-time occlusion; a comparative study.

We have compared the effects on visual acuity and binocular functions of grating stimulation (CAM therapy) and full-time occlusion in 38 4-year-old, previously untreated amblyopic children. The patients were divided into subgroups with regard to amblyopia type and fixation pattern. We found that grating stimulation was slightly better than occlusion in improving visual acuity of anisometropic amblyopes with central fixation, but that both types of therapy were equally effective in strabismic amblyopia with central fixation and in amblyopia with eccentric fixation. However, maximal treatment effects were not reached with grating stimulation alone, as shown at follow-up after continued conventional therapy. Grating stimulation may be regarded as a valuable method at the initiation of treatment, particularly in anisometropic amblyopia, but it has to be supplemented with occlusion, which still must be regarded as the prime form of amblyopia therapy.