An inner city preschool visual screening programme: long-term visual results

Prevalence of residual amblyopia in adulthood and its association on educational outcome and quality of life in the Northern Finland Birth Cohort

PURPOSE

The purpose of the current study was to evaluate the prevalence of residual amblyopia in adults in a population screened and treated in childhood. We also wanted to evaluate the association of amblyopia on school success, level of education, and quality of life.

METHODS

This is a follow-up study of 2708 subjects of the Northern Finland Birth Cohort. At the age of 46, the subjects took part in ophthalmic examinations, including the measurement of best-corrected visual acuity (BCVA) and refraction. Residual amblyopia was defined as BCVA 20/30 or less (logMAR ≥0.2) in one or both eyes or a two-line interocular visual acuity difference and absence of any pathological ocular factors. The quality of life was assessed with a 15D questionnaire, and educational outcome, school success, and episodic memory with a CANTAB-PAL (paired associates learning) test were evaluated.

RESULTS

The prevalence of amblyopia in the current adult population aged 46 years was 1.3% (n = 36). At 14 years, the amblyopia subjects had had significant differences in mean spherical equivalent between the amblyopic and fellow eye and strabismus more often than controls. No significant differences were observed in the CANTAB-PAL test or in educational outcome. However, amblyopia subjects had significant difficulties in the 15D questionnaire in terms of vision (54% vs. 34%, p = 0.01).

CONCLUSION

Due to screening and treatment in childhood, the number of adults with residual amblyopia was low. Despite minor visual impairment and discomfort, they cope very well in life in terms of educational outcome and quality of life.

Reliance on visual feedback from ocular accommodation on motor skills in children with developmental coordination disorder and typically developing controls

Children with developmental coordination disorder (DCD) present with marked impairments in motor skills, including visual-motor integration. Oculomotor anomalies are more prevalent in children with DCD than typically developing children. Children with DCD further demonstrate altered use of visual feedback compared to typically developing controls. We investigated whether the accommodation system, a key component of the oculomotor system, contributes to visual feedback during fine and gross motor skills performance; and whether children with DCD demonstrate differences in reliance on visual feedback from accommodation. Minus dioptre lenses were used to maximally induce accommodation and impede accommodation dynamics. Children with DCD and typically developing controls performed motor skills tests assessing balance, upper limb coordination, visual-motor performance, gross and fine dexterity. Motor skills performance in controls was significantly affected by impeded accommodation in all tasks. Children with DCD demonstrated reliance on accommodation feedback in upper limb and visual-motor tasks only. Children with DCD may be less reliant on visual feedback obtained from accommodation due to adaptive mechanisms to overcome faulty information in the presence of oculomotor anomalies. These results strengthen our previous findings that accommodation anomalies contribute to motor skills impairment, and suggest that performance on these motor tasks is heavily reliant on visual feedback from accommodation.

Amblyopia Outcomes Through Clinical Trials and Practice Measurement: Room for Improvement: The LXXVII Edward Jackson Memorial Lecture

PURPOSE

To describe amblyopia prevalence and outcomes using results from randomized studies and a clinical registry.

DESIGN

Review of published studies, analysis of data in Intelligent Research in Sight (IRIS) Registry from 2013 to 2019, personal perspective.

METHODS

Literature review, analysis of IRIS Registry data and IRIS-50, a visual acuity quality measure.

RESULTS

Clinical trials have reduced the treatment burden of amblyopia by reducing hours of patching and frequency of atropine eye drops with clinical success of about 83%. There is no appreciable age effect if treatment is started before 5 years of age, outcomes are stable to at least 15 years of age, and treatment can be somewhat effective until 12 years of age. The IRIS Registry identified 1,760,066 individuals with amblyopia for a prevalence of 2.47%. Refractive error alone accounted for 68.9% of childhood cases. Mean amblyopic eye visual acuity improved 1.8 lines for children 3-6 years of age and 0.8 lines for 7-12 years, but mean residual amblyopia was more than 2 lines. Among 18,841 children aged 3-7 years eligible for IRIS-50, 77.3% were successful. The odds ratios for success were significantly lower for African-American (0.67; 95% confidence interval [CI] = 0.58 to 0.78) and Hispanic or Latino (0.84; 95% CI = 0.75 to 0.94) children compared with white children.

CONCLUSIONS

Clinical trials provided evidence of a beneficial effect from several treatments, with substantially reduced doses than previously recommended. Registry data from clinical practice found residual visual acuity impairment among all ages and races, especially among minorities.

Atropine vs patching for treatment of moderate amblyopia: follow-up at 15 years of age of a randomized clinical trial

IMPORTANCE

Initial treatment for amblyopia of the fellow eye with patching and atropine sulfate eyedrops improves visual acuity. Long-term data on the durability of treatment benefit are needed.

OBJECTIVE

To report visual acuity at 15 years of age among patients who were younger than 7 years when enrolled in a treatment trial for moderate amblyopia.

DESIGN, SETTING, AND PARTICIPANTS

In a multicenter clinical trial, 419 children with amblyopia (visual acuity, 20/40 to 20/100) were randomly assigned to patching (minimum of 6 h/d) or atropine sulfate eyedrops, 1% (1 drop daily), for 6 months. Treatment after 6 months was at the discretion of the investigator. Two years after enrollment, an unselected subgroup of 188 children were enrolled into long-term follow-up.

INTERVENTION

Initial treatment with patching or atropine with subsequent treatment at investigator discretion.

MAIN OUTCOMES AND MEASURES

Visual acuity at 15 years of age with the electronic Early Treatment Diabetic Retinopathy Study test in amblyopic and fellow eyes.

RESULTS

Mean visual acuity in the amblyopic eye measured in 147 participants at 15 years of age was 0.14 logMAR (approximately 20/25); 59.9% of amblyopic eyes had visual acuity of 20/25 or better and 33.3%, 20/20 or better. Mean interocular acuity difference (IOD) at 15 years of age was 0.21 logMAR (2.1 lines); 48.3% had an IOD of 2 or more lines and 71.4%, 1 or more lines. Treatment (other than spectacles) was prescribed for 9 participants (6.1%) aged 10 to 15 years. Mean IOD was similar at examinations at 10 and 15 years of age (2.0 and 2.1 logMAR lines, respectively; P = .39). Better visual acuity at the 15-year examination was achieved in those who were younger than 5 years at the time of entry into the randomized clinical trial (mean logMAR, 0.09) compared with those aged 5 to 6 years (mean logMAR, 0.18; P < .001). When we compared subgroups based on original treatment with atropine or patching, no significant differences were observed in visual acuity of amblyopic and fellow eyes at 15 years of age (P = .44 and P = .43, respectively).

CONCLUSIONS AND RELEVANCE

At 15 years of age, most children treated for moderate amblyopia when younger than 7 years have good visual acuity, although mild residual amblyopia is common. The outcome is similar regardless of initial treatment with atropine or patching. The results indicate that improvement occurring with amblyopia treatment is maintained until at least 15 years of age.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00000170.

Static and dynamic measurements of accommodation in individuals with down syndrome

PURPOSE

To identify whether static and dynamic aspects of accommodation other than accuracy are deficient in individuals with Down syndrome (DS) and whether poor accommodation is related to sensory or motor pathway deficits.

METHODS

Static aspects of accommodation (maximum accommodative response and lag) were measured with an autorefractor for both proximal and minus lens demands. Dynamic aspects of accommodation (latency, peak velocity, microfluctuations) were recorded at 30 Hz with a custom-built photorefractor as subjects viewed a movie switching between 11 m and 50, 33, 25, or 20 cm. Thirty-six subjects with DS were recruited (age 3 to 39 years), and 24 (67%) had useable responses for at least one study measurement for comparison with 140 controls (3 to 40 years) from a previously published cohort.

RESULTS

DS subjects had lower maximum accommodative responses (mean = 2.52 ± 1.66 D) and higher lags (1.81 ± 1.30 D for 33 cm demand) than controls for both proximal and minus lens stimuli. DS subjects had greater microfluctuations (one-way ANCOVA, P < 0.001), and a small percentage of the total number of latency measurements (17% accommodative and 16% disaccommodative) were longer than controls. Peak velocities of accommodation and disaccommodation were not different between groups (one-way ANCOVA, P = 0.143).

CONCLUSIONS

Peak velocities of accommodation and disaccommodation (primarily motor aspects) did not differ between controls and DS subjects; however, latencies (primarily sensory) and microfluctuations (combined motor and sensory) were poorer in DS subjects. These results suggest that poor accommodative accuracy in individuals with DS may be predominantly related to sensory deficits.

Termination of amblyopia treatment: when to stop follow-up visits and risk factors for recurrence

BACKGROUND

This study estimated when it is safe to stop follow-up visits after cessation of amblyopia treatment and to identify factors associated with deterioration of visual acuity.

METHODS

Study patients included 282 patients aged 7 to 13 years who were monitored for deterioration after cessation of amblyopia treatment (median follow-up: 3.9 years).

RESULTS

Six (2.1%) patients lost 2 or more logarithm of the minimum angle of resolution levels of visual acuity and 77 (27.3%) patients lost 1 or more Snellen lines of visual acuity. Good compliance with re-treatment stopped further deterioration and lost visual acuity was regained (average follow-up after re-treatment: 3.3 years). Life table analysis indicated that 95% of the cases that deteriorated occurred within 24 months after cessation of treatment. Multivariable analysis corrected for duration of treatment uncovered factors independently associated with deterioration.

CONCLUSION

A clinically important risk of deterioration of visual acuity was found during the first 2 years after cessation of amblyopia treatment. Follow-up time longer than 2 years is recommended in the presence of a developing risk factor such as increasing anisometropia. With prompt re-treatment and good compliance, deterioration can be stopped and visual acuity can be restored.

Minus lens stimulated accommodative lag as a function of age

PURPOSE

Previous studies in children report reduced accommodative responses with minus lens-stimulated demands compared with proximal demands. This study seeks to identify age-related changes in accommodative lag with minus lens-stimulated demands in subjects from preschoolers to adults.

METHODS

Accommodative responses were measured in 101 subjects (3 to 40 years) with at least 10 subjects in each 5-year age bin. Subjects monocularly viewed a high-contrast target at 33.3 cm on the near-point rod of the Grand Seiko autorefractor. Measurements of refraction were taken as the subject viewed the target. Accommodative lag was defined as the difference between demand and measured response. Four additional demands were tested by introducing minus lenses [-1 to -4 diopter (D)] in the spectacle plane of the viewing eye. Maximum accommodative amplitudes were determined by presenting additional lenses until the measured response plateaued or peaked. Accommodative demands and responses were adjusted to the corneal plane. RESULTS.: Accommodative lag showed a significant linear decrease with age for subjects 3 to 20 years for each of the first four demands (3 D, 3.92 D, 4.80 D, 5.67 D, p <or= 0.013) and approached significance for the largest demand (6.52 D, p = 0.053). For the entire group, accommodative lag increased with increasing stimulus demand, with the largest increase occurring for subjects aged 30 to 40 years as stimulus demands approached the subjects' maximum amplitude. For subjects aged 3 to 20 years, multilevel modeling analysis revealed a significant relationship between age and lag (p < 0.0001) and a significant relationship between maximum amplitude and the increase in lag per unit increase in stimulus demand (p = 0.0032).

CONCLUSIONS

These findings suggest the accuracy of accommodation to minus lens-stimulated accommodation improves throughout the school years and that the degree to which lag increases with increasing demand is related to maximum accommodative amplitude rather than age.

A randomized trial of atropine vs patching for treatment of moderate amblyopia: follow-up at age 10 years

OBJECTIVE

To determine the visual acuity outcome at age 10 years for children younger than 7 years when enrolled in a treatment trial for moderate amblyopia.

METHODS

In a multicenter clinical trial, 419 children with amblyopia (visual acuity, 20/40-20/100) were randomized to patching or atropine eyedrops for 6 months. Two years after enrollment, a subgroup of 188 children entered long-term follow-up. Treatment after 6 months was at the discretion of the investigator; 89% of children were treated.

MAIN OUTCOME MEASURE

Visual acuity at age 10 years with the electronic Early Treatment Diabetic Retinopathy Study test.

APPLICATION TO CLINICAL PRACTICE

Patching and atropine eyedrops produce comparable improvement in visual acuity that is maintained through age 10 years.

RESULTS

The mean amblyopic eye acuity, measured in 169 patients, at age 10 years was 0.17 logMAR (logarithm of the minimum angle of resolution) (approximately 20/32), and 46% of amblyopic eyes had an acuity of 20/25 or better. Age younger than 5 years at entry into the randomized trial was associated with a better visual acuity outcome (P < .001). Mean amblyopic and sound eye visual acuities at age 10 years were similar in the original treatment groups (P = .56 and P = .80, respectively).

CONCLUSIONS

At age 10 years, the improvement of the amblyopic eye is maintained, although residual amblyopia is common after treatment initiated at age 3 years to younger than 7 years. The outcome is similar regardless of initial treatment with atropine or patching.

Outcomes of 6 hour part-time occlusion treatment combined with near activities for unilateral amblyopia

PURPOSE

To evaluate the outcome of the part-time occlusion therapy with near activities in monocular amblyopic patients according to gender, age, severity of amblyopia, and the cause of amblyopia.

METHODS

Fifty eight patients who were prescribed part-time occlusion therapy with near activity from July 1998 to October 2004, were included in this retrospective study. All patients were divided into groups by gender, age, severity of amblyopia, and the cause of amblyopia. Main outcome measures were best corrected visual acuity, line improvement, and success rate.

RESULTS

At the end of patch therapy, visual acuity improved from baseline by an average of 3.2+/-2.5 lines (0.33+/-0.26 log MAR), and follow-up period was 19.71+/-14.61 months (1.62+/-1.20 years). At the last follow-up, visual acuity improved from baseline by an average of 3.7+/-2.4 lines (0.38+/-0.26 log MAR), and follow-up period was 37.41+/-25.83 months (3.08+/-2.12 years). The success rate was 86% (50 patients) at the end of patch therapy. In 44 patients out of 50 patients (88%), the visual acuity was maintained. While 43 patients out of 47 patients who were less than 7 years old (91%) achieved success, 7 patients out of 11 patients 7 years or older (64%) achieved success (p=0.035).

CONCLUSIONS

Six-hour part-time occlusion treatment combined with near activities appears to be favorable in treating 58 children during follow-up of mean 3.08 years. The significant factor was the age at initial treatment.

Minus-lens-stimulated accommodative amplitude decreases sigmoidally with age: a study of objectively measured accommodative amplitudes from age 3

PURPOSE

Guidelines for predicting accommodative amplitude by age are often based on subjective push-up test data that overestimate the accommodative response. Studies in which objective measurements were used have defined expected amplitudes for adults, but expected amplitudes for children remain unknown. In this study, objective methods were used to measure accommodative amplitude in a wide age range of individuals, to define the relationship of amplitude and age from age 3.

METHODS

Accommodative responses were measured in 140 subjects aged 3 to 40 years. Measurements were taken with the Grand Seiko autorefractor (RyuSyo Industrial Co., Ltd., Kagawa, Japan) as the subjects viewed a high-contrast target at 33 cm through minus lenses of increasing power until the responses showed no further increase in accommodation.

RESULTS

The maximum accommodative amplitude of each subject was plotted by age, and a curvilinear function fit to the data: y = 7.33 - 0.0035(age - 3)(2) (P < 0.001). Tangent analysis of the fit indicated that the accommodative amplitude remained relatively stable until age 20. Data from this study were then pooled with objective amplitudes from previous studies of adults up to age 70. A sigmoidal function was fit to the data: y = 7.083/(1 + e([0.2031(age-36.2)-0.6109])) (P < 0.001). The sigmoidal function indicated relatively stable amplitudes below age 20 years, a rapid linear decline between 20 and 50 years, and a taper to 0 beyond 50 years.

CONCLUSIONS

These data indicate that accommodative amplitude decreases in a curvilinear manner from 3 to 40 years. When combined with data from previous studies, a sigmoidal function describes the overall trend throughout life with the biggest decrease occurring between 20 and 50 years.

Impact of amblyopia on vision at age 12 years: findings from a population-based study

AIMS

To report prevalence of amblyopia and long-term impact of its treatment on vision in a population-based sample of 12-year-old Australian children.

METHODS

Logarithm of minimum angle of resolution (logMAR) visual acuity (VA) was measured in 2353 children (response rate 75.3%); visual impairment was defined as VA<6/12. Amblyopia was defined using various criteria of best-corrected VA, together with an amblyogenic factor and absence of significant organic pathology. Corroborative historical data on previous diagnosis and treatment were obtained from parental questionnaires.

RESULTS

Forty-four children (1.9%) were diagnosed with amblyopia, unilateral in 40 and bilateral in four. Isolated anisometropia was the most frequent cause (41%), followed by strabismus (25%), combined anisometropia and strabismus (23%), and high ametropia (9%). Myopia, hyperopia, and astigmatism were present in 28, 51, and 44% of amblyopic children, respectively, compared to 12, 4, and 9% of non-amblyopic children. Mean best-corrected VA in amblyopic eyes was 44.5 logMAR letters (Snellen equivalent 6/9), range: 11-60 letters. Most children with amblyopia (84%) had been treated. Only 27% were visually impaired in their amblyopic eye.

CONCLUSIONS

This report documents a low amblyopia prevalence in a population of 12-year-old Australian children. Amblyopic visual impairment was infrequent in this sample despite absence of mandatory vision screening.

Does amblyopia affect educational, health, and social outcomes? Findings from 1958 British birth cohort

OBJECTIVE

To determine any association of amblyopia with diverse educational, health, and social outcomes in order to inform current debate about population screening for this condition.

DESIGN, SETTING, AND PARTICIPANTS

Comparison of 8432 people with normal vision in each eye with 429 (4.8%) people with amblyopia (childhood unilateral reduced acuity when tested with correction and unaccounted for by eye disease) from the 1958 British birth cohort, with respect to subsequent health and social functioning.

RESULTS

No functionally or clinically significant differences existed between people with and without amblyopia in educational outcomes, behavioural difficulties or social maladjustment, participation in social activities, unintended injuries (school, workplace, or road traffic accidents as driver), general or mental health and mortality, paid employment, or occupation based social class trajectories.

CONCLUSIONS

It may be difficult to distinguish, at population level, between the lives of people with amblyopia and those without, in terms of several important outcomes. A pressing need exists for further concerted research on what it means to have amblyopia and, specifically, how this varies with severity and how it changes with treatment, so that screening programmes can best serve those who have the most to gain from early identification.

Amblyopia characterization, treatment, and prophylaxis

Amblyopia has a 1.6-3.6% prevalence, higher in the medically underserved. It is more complex than simply visual acuity loss and the better eye has sub-clinical deficits. Functional limitations appear more extensive and loss of vision in the better eye of amblyopes more prevalent than previously thought. Amblyopia screening and treatment are efficacious, but cost-effectiveness concerns remain. Refractive correction alone may successfully treat anisometropic amblyopia and it, minimal occlusion, and/or catecholamine treatment can provide initial vision improvement that may improve compliance with subsequent long-duration treatment. Atropine penalization appears as effective as occlusion for moderate amblyopia, with limited-day penalization as effective as full-time. Cytidin-5'-diphosphocholine may hold promise as a medical treatment. Interpretation of much of the amblyopia literature is made difficult by: inaccurate visual acuity measurement at initial visit, lack of adequate refractive correction prior to and during treatment, and lack of long-term follow-up results. Successful treatment can be achieved in at most 63-83% of patients. Treatment outcome is a function of initial visual acuity and type of amblyopia, and a reciprocal product of treatment efficacy, duration, and compliance. Age at treatment onset is not predictive of outcome in many studies but detection under versus over 2-3 years of age may be. Multiple screenings prior to that age, and prompt treatment, reduce prevalence. Would a single early cycloplegic photoscreening be as, or more, successful at detection or prediction than the multiple screenings, and more cost-effective? Penalization and occlusion have minimal incidence of reverse amblyopia and/or side-effects, no significant influence on emmetropization, and no consistent effect on sign or size of post-treatment changes in strabismic deviation. There may be a physiologic basis for better age-indifferent outcome than tapped by current treatment methodologies. Infant refractive correction substantially reduces accommodative esotropia and amblyopia incidence without interference with emmetropization. Compensatory prism, alone or post-operatively, and/or minus lens treatment, and/or wide-field fusional amplitude training, may reduce risk of early onset esotropia. Multivariate screening using continuous-scale measurements may be more effective than traditional single-test dichotomous pass/fail measures. Pigmentation may be one parameter because Caucasians are at higher risk for esotropia than non-whites.

Long-term follow-up of occlusion therapy in amblyopia

OBJECTIVE

To determine whether the results of occlusion therapy for amblyopia are maintained into adulthood.

DESIGN

Prospective, observational case series.

PARTICIPANTS

Fifty-four patients, who were successfully treated in childhood for unilateral amblyopia by occlusion, were followed up to the age of 9 years, were evaluated in 1984 for long-term results 6.4 years on average after cessation of treatment, and accepted our invitation for reevaluation in 1999.

METHODS

All patients were given a complete eye examination. The visual acuity (VA) was measured.

RESULTS

The average period of follow-up was 21.5 years (range, 17.2-25.1 years). The mean age at the most recent examination was 29.0 +/- 2.1 years (range, 25.1-34). At this examination, a best-corrected visual acuity (BCVA) of 20/40 or better was achieved by 72.3% of the patients. The mean BCVA was 20/35 (20/25-20/70) at the end of occlusion therapy, 20/45 (20/20-20/300) in 1984, and 20/34 (20/15-20/100) at the present examination. Relative to the results at the end of therapy, BCVA at the present examination was maintained or improved in 66.7% of the patients. Relative to 1984, the BCVA in 1999 was maintained or improved in 87% of the patients.

MAIN OUTCOME MEASURE

Visual acuity.

CONCLUSION

Comparative evaluation of BCVA at a long-term follow-up examination, performed 21.5 years on average after cessation of occlusion therapy, showed that VA was maintained or improved in two thirds of patients who had been successfully treated by occlusion for unilateral amblyopia in childhood.

Efficacy of occlusion for strabismic amblyopia: can an optimal duration be identified?

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 = 119) in response to successive 200 hour blocks of occlusion up to > or =1000 hours, in an attempt to isolate an optimal occlusion regime.

RESULTS

Visual acuity improved for more of the amblyopic eyes of the occluded (74%) than the spectacles only group (59%), and only one child from the latter group deteriorated. Mean visual acuity improved for both eyes of both treatment groups, but the change was significantly larger for the strabismic eyes of the occluded group overall and within the first 6 month period (p <0. 05). Occlusion was only effective for the first 400 hours worn. Subsequent visual improvement was bilateral and symmetrical.

CONCLUSION

Occlusion is more effective in the treatment of strabismic amblyopia than spectacles alone, and the effect is optimal within the first 6 months of wear. In terms of occlusion duration, maximal improvement occurs in response to 400 hours of occlusion wear or less, and to full time occlusion. Visual maturation continues, but is retarded for amblyopic eyes.

1999 Costenbader Lecture. Outcome study in amblyopia: treatment and practice pattern variations

This study retrospectively evaluates the results of amblyopia therapy and suggests hypotheses for future study. We address the various methods of treatment and evaluate the results from the most common therapy techniques. Practice pattern variations were analyzed in addition to the analysis of overall results. For ophthalmologists, there is a need to determine whether actual medical practice approaches the established standard of care, if it exists at all. How often are medical procedures, thought to be appropriate, based on anecdotal observation (case reports) rather than hard data (clinical trials)? The 3 types of vision loss evaluated were strabismic, anisometropic, and deprivation amblyopia. The methods of treatment studied were full-time patching part-time occlusion, penalization, and occlusion of the contact lens. Nine centers, thought to have private as well as indigent patients, were recruited to participate in this study. The centers responded by filling out an extensive questionnaire and sending the information through the World Wide Web for inclusion in a spreadsheet. This information was then collated, and various statistical programs tabulated the results. Although trends, as a consequence of therapy, are suggested from our retrospective analysis, concrete results can only arise from a randomized prospective study. The study included 279 patients. There were a similar number of male and female patients. Only 77% of the patients without fusion before treatment had either single binocular vision or peripheral fusion at the conclusion of therapy. The log improvement of vision was significant in each group. Factors that potentially influenced the results were severity of distance acuity in the amblyopic eye before treatment, duration of treatment, and length of daily patching. The paper suggests that worse vision, not better vision, at the beginning, predicts better outcome in terms of improvement of visual acuity. For example, visual acuity less than 20/70 at the initiation of treatment led to better visual results of geometric log improvement. Surprisingly, among the 9 centers studied, there was a statistically significant difference in many of the areas related to practice patterns. Patient compliance, which directly affects outcome, was highly variable and is a factor that may be readily influenced by the treating physician.

The detection, prevention, and rehabilitation of amblyopia

Some of the past year's important papers on amblyopia are reviewed. Preschool screening for amblyopia is still controversial in regard to its effectiveness, the best age, and the most cost-effective method. In Sweden, where screening for amblyopia is well established, the prevalence of deep and moderate amblyopia has been markedly reduced. Several studies in the past year underscored the importance of anisometropia as a risk factor for amblyopia. Clear evidence for the importance of early treatment of unilateral cataracts in the first 8 weeks of life has been shown. Cytidine-5'-diphosphocholine administration has been shown to positively influence amblyopia and represents, in addition to levodopa, another promising pharmacologic treatment.