Slow Binocular Reading in Amblyopic Children Is a Fellow Eye Deficit

SIGNIFICANCE

Amblyopic children read 25% slower than their peers during binocular silent reading.

PURPOSE

We compared binocular reading to fellow eye reading to determine whether slow reading in amblyopic children is due to binocular inhibition; that is, the amblyopic eye is interfering during binocular reading.

METHODS

In a cross-sectional study, 38 children with amblyopia and 36 age-similar control children who completed grades 1 to 6 were enrolled. Children silently read grade-appropriate paragraphs during binocular reading and fellow eye reading while wearing ReadAlyzer eye-tracking goggles (Compevo AB, Stockholm, Sweden). Reading rate, number of forward saccades, number of regressive saccades, and fixation duration were analyzed between groups and between viewing conditions. We also examined whether sensory factors (amblyopia severity, stereoacuity, suppression) were related to slow reading.

RESULTS

For amblyopic children, binocular reading versus fellow eye reading did not differ for reading rate (176 ± 60 vs. 173 ± 53 words per minute, P = .69), number of forward saccades (104 ± 35 vs. 97 ± 33 saccades/100 words, P = .18), number of regressive saccades (21 ± 15 vs. 22 ± 13 saccades/100 words, P = .75), or fixation duration (0.31 ± 0.06 vs. 0.32 ± 0.07 seconds, P = .44). As expected, amblyopic children had a slower reading rate and more forward saccades than control children during binocular reading and fellow eye reading. Slow reading was not related to any sensory factors.

CONCLUSIONS

Binocular reading did not differ from fellow eye reading in amblyopic children. Thus, binocular inhibition is unlikely to play a role in slow binocular reading and is instead a fellow eye deficit that emerges from a disruption in binocular visual experience during development.

Reach Kinematics During Binocular Viewing in 7- to 12-Year-Old Children With Strabismus

Purpose

Eye–hand coordination is essential for normal development and learning. Discordant binocular experience from childhood strabismus results in sensory and ocular motor impairments that can affect eye–hand coordination. We assessed reach kinematics during visually guided reaching in children treated for strabismus compared with controls.

Methods

Thirty-six children aged 7 to 12 years diagnosed with esotropia, a form of strabismus, and a group of 35 age-similar control children were enrolled. Reach movements during visually guided reaching were recorded using the LEAP Motion Controller. While viewing binocularly, children reached out and touched a small dot that appeared randomly in one of four locations (±5° or ±10°). Kinematic measures were reach reaction time, total reach duration, peak velocity, acceleration duration, and deceleration duration. Touch accuracy and factors associated with impaired reach kinematics were evaluated.

Results

Strabismic children had longer total reach duration (545 ± 60 ms vs. 504 ± 43 ms; P = 0.002), had longer deceleration duration (343 ± 54 ms vs. 312 ± 45 ms; P = 0.010), and were less accurate (93% ± 6% vs. 96% ± 5%, P = 0.007) than controls. No differences were found for reach reaction time, peak velocity, or acceleration duration (all Ps ≥ 0.197). Binocular dysfunction was more related to slow reaching than amblyopic eye visual acuity.

Conclusions

Strabismus affects visually guided reaching in children, with slower reaching in the final approach and reduced endpoint accuracy. Binocular dysfunction was predictive of slow reaching. Unlike strabismic adults who show longer acceleration duration, longer deceleration in the final approach in strabismic children indicates a difference in control that could be due to reduced ability to use visual feedback.

Factors Associated with Impaired Motor Skills in Strabismic and Anisometropic Children

Purpose

We evaluated motor skills in children diagnosed with strabismus and anisometropia, with or without amblyopia, and explored factors associated with impairments.

Methods

A total of 143 strabismic and anisometropic children 3 to 13 years of age (96 amblyopic, 47 nonamblyopic) and a group of age-similar 35 control children completed Manual Dexterity, Aiming and Catching, and Balance tasks from the Movement Assessment Battery for Children, Second Edition. Raw scores were converted to standardized scores, and amblyopic and nonamblyopic children were compared to controls. Clinical and sensory factors associated with motor performance were also evaluated.

Results

Overall, amblyopic and nonamblyopic children were three to six times more likely than controls to be at risk for or to have a total motor impairment (≤15th percentile). Although amblyopic children scored lower than controls for the Manual Dexterity, Aiming and Catching, and Balance tasks, nonamblyopic children scored lower on Manual Dexterity only. Factors related to manual dexterity deficits include the presence of amblyopia and binocularity deficits typical of these eye conditions. Aiming, catching, and balance deficits were most pronounced in children with an infantile onset of the eye condition, a history of strabismus, and reduced binocularity.

Conclusions

Amblyopia and strabismus disrupt the development of motor ability in children. These findings highlight the widespread effects of discordant binocular input early in life and the visual acuity and binocularity deficits typical of these eye conditions.

A randomized clinical trial of contrast increment protocols for binocular amblyopia treatment

BACKGROUND

Most clinical trials of contrast-rebalanced binocular amblyopia treatment used a contrast increment protocol of 10% daily with successful play. Paired with a definition of success requiring only 15-30 min/day of gameplay, this increment protocol could allow children to reach 100% fellow eye contrast in 3-9 hours; however, this may not provide adequate therapeutic time with reduced fellow eye contrast. The purpose of this study was to compare the original protocol against three alternative contrast increment protocols designed to increase the number of treatment hours.

METHODS

In this prospective study, 63 amblyopic children (4-10 years; amblyopic eye visual acuity, 20/40-125) were randomly assigned one of four daily contrast increment protocols for 4 weeks, all starting with 20% fellow eye contrast: 10%, 5%, 0%, or 10% for first 4 weeks then reset to 20% and repeat 10% increment for the final 4 weeks. Children played contrast-rebalanced games for 1 hour/day, 5 days/week. Best-corrected visual acuity, stereoacuity, and suppression were assessed at baseline and every 2 weeks until the 8-week outcome visit.

RESULTS

At baseline, mean amblyopic eye best-corrected visual acuity was 0.47 ± 0.14 logMAR (20/60), improving overall 0.14 ± 0.08 logMAR (1.4 lines; P < 0.0001) at 8 weeks. All four protocols resulted in similar improvement in visual acuity (0.13-0.16 logMAR; all Ps < 0.0002). Stereoacuity and suppression also improved (all Ps < 0.05).

CONCLUSIONS

None of the new protocols resulted in less improvement than the original 10% contrast increment protocol. Contrast-rebalanced binocular games yielded significant improvements in visual acuity, stereoacuity, and suppression with or without daily contrast increments.

Self-perception in Children Aged 3 to 7 Years With Amblyopia and Its Association With Deficits in Vision and Fine Motor Skills

Importance

Deficits in fine motor skills and slow reading speed have been reported in school-aged children and adults with amblyopia. These deficits were correlated with lower self-perception of athletic and cognitive competence. Although perceived competence and social acceptance are key determinants of developing self-perception in young children, the association of amblyopia with self-perception and the association of altered self-perception with fine motor skills to date have not been reported for young children aged 3 to 7 years.

Objectives

To investigate whether amblyopia is associated with altered self-perception in young children and to assess whether any differences in self-perception are associated with deficits in vision and fine motor skills.

Design, Setting, and Participants

In this cross-sectional study, conducted at a pediatric vision laboratory from January 10, 2016, to May 4, 2018, healthy children aged 3 to 7 years (preschool to second grade) were enrolled, including 60 children with amblyopia; 30 children who never had amblyopia but had been treated for strabismus, anisometropia, or both; and 20 control children.

Main Outcomes and Measures

Self-perception was assessed using the Pictorial Scale of Perceived Competence and Social Acceptance for Young Children, which includes the following 4 specific domains: cognitive competence, peer acceptance, physical competence, and maternal acceptance (total score range, 1-4; higher scores indicate higher perceived competence or acceptance). Fine motor skills were evaluated with the Manual Dexterity and Aiming and Catching scales of the Movement Assessment Battery for Children, second edition (score range, 1-19; higher scores indicate better skill performance). Visual acuity and stereoacuity also were assessed.

Results

Children with amblyopia (28 girls and 32 boys; mean [SD] age, 6.3 [1.3] years) had significantly lower mean (SD) peer acceptance and physical competence scores compared with the control children (peer acceptance, 2.74 [0.66] vs 3.11 [0.36]; mean difference, 0.37; 95% CI for difference, 0.06-0.68; P = .04; and physical competence, 2.86 [0.60] vs 3.43 [0.52]; mean difference, 0.57; 95% CI for difference, 0.27-0.87; P = .009). Among the children with amblyopia, self-perception of physical competence was significantly correlated with aiming and catching skills (r = 0.43; 95% CI, 0.10-0.67; P = .001) and stereoacuity (r = -0.39; 95% CI, -0.05 to -0.65; P = .02). Children treated for strabismus or anisometropia, but who never had amblyopia, also had significantly lower mean (SD) physical competence scores compared with control children (2.89 [0.54] vs 3.43 [0.52]; 95% CI for difference, 0.23-0.85; P = .03).

Conclusions and Relevance

These findings suggest that lower self-perception of peer acceptance and physical competence identify the broad effects of altered visual development in the everyday life of children with amblyopia.

Atropine 0.01% Eye Drops for Myopia Control in American Children: A Multiethnic Sample Across Three US Sites

INTRODUCTION

Topical atropine eye drops at low concentrations have been shown to slow myopia progression in East Asian studies. This study explored the effect of atropine 0.01% eye drops on controlling myopia progression in a multiethnic cohort of children in the USA.

METHODS

A multicenter retrospective case-control study (n = 198) quantified the effect of adding nightly atropine 0.01% eye drops to treatment as usual on the progression of childhood (ages 6-15 years) myopia. Cases included all children treated with atropine for at least 1 year. Controls were matched to cases on both age (± 6 months) and baseline spherical equivalent refraction (SER) (± 0.50 diopters, D) at treatment initiation. The primary endpoint was the average SER myopia progression after 1, 1.5, and 2 years of therapy. A secondary outcome was the percentage of subjects with a clinically significant worsening of myopia, defined as a greater than - 0.75 D SER increase in myopia.

RESULTS

The average baseline SERs for the atropine (n = 100) and control (n = 98) groups were similar (- 3.1 ± 1.9 D and - 2.8 ± 1.6 D, respectively) (p = 0.23). The average SER increase from baseline was significantly less for the atropine group than the control group at year 1 (- 0.2 ± 0.8 D compared with - 0.6 ± 0.4 D, p < 0.001) and at year 2 (- 0.3 ± 1.1 D compared with - 1.2 ± 0.7 D, p < 0.001). Secondary analysis at year 2 revealed that 80% of the control group vs. 37% of the atropine group experienced clinically significant worsening myopia of at least - 0.75 D (p < 0.001). There were no major safety issues reported in either group.

CONCLUSION

Similar to results reported in Asia, atropine 0.01% eye drops significantly reduced myopia progression in a cohort of US children over 2 years of treatment.

FUNDING

Nevakar, Inc. Plain language summary available for this article.

Self-perception of School-aged Children With Amblyopia and Its Association With Reading Speed and Motor Skills

Importance

Reading and eye-hand coordination deficits in children with amblyopia may impede their ability to demonstrate their knowledge and skills, compete in sports and physical activities, and interact with peers. Because perceived scholastic, social, and athletic competence are key determinants of self-esteem in school-aged children, these deficits may influence a child's self-perception.

Objective

To determine whether amblyopia is associated with lowered self-perception of competence, appearance, conduct, and global self-worth and whether the self-perception of children with amblyopia is associated with their performance of reading and eye-hand tasks.

Design, Setting, and Participants

This cross-sectional study was conducted from January 2016 to June 2017 at the Pediatric Vision Laboratory of the Retina Foundation of the Southwest and included healthy children in grades 3 to 8, including 50 children with amblyopia; 13 children without amblyopia with strabismus, anisometropia, or both; and 18 control children.

Main Outcomes and Measures

Self-perception was assessed using the Self-perception Profile for Children, which includes 5 domains: scholastic, social, and athletic competence; physical appearance; behavioral conduct; and a separate scale for global self-worth. Reading speed and eye-hand task performance were evaluated with the Readalyzer (Bernell) and Movement Assessment Battery for Children, 2nd Edition. Visual acuity and stereoacuity also were assessed.

Results

Of 50 participants, 31 (62%) were girls, 31 (62%) were non-Hispanic white, 6 (12%) were Hispanic white, 3 (6%) were African American, 4 (8%) were Asian/Pacific Islander, and 3 (6%) were more than 1 race/ethnicity, and the mean [SD] age was 10.6 [1.3] years. Children with amblyopia had significantly lower scores than control children for scholastic (mean [SD], 2.93 [0.74] vs 3.58 [0.24]; mean [SD] difference, 0.65 [0.36]; 95% CI, 0.29-1.01; P = .004), social (mean [SD], 2.95 [0.64] vs 3.62 [0.35]; mean [SD] difference, 0.67 [0.32]; 95% CI, 0.35-0.99] P < .001), and athletic (mean [SD], 2.61 [0.65] vs 3.43 [0.52]; mean [SD] difference, 0.82 [0.34]; 95% CI, 0.48-1.16; P = .001) competence domains. Among children with amblyopia, a lower self-perception of scholastic competence was associated with a slower reading speed (r = 0.49, 95% CI, 0.17-0.72; P = .002) and a lower self-perception of scholastic, social, and athletic competence was associated with worse performance of aiming and catching (scholastic r = 0.48; 95% CI, 0.16-0.71; P = .007; social r = 0.63; 95% CI, 0.35-0.81; P < .001; athletic r = 0.53; 95% CI, 0.21-0.75; P = .003). No differences in the self-perception of physical appearance (mean [SD], 3.32 [0.63] vs 3.64 [0.40]), conduct (mean [SD], 3.09 [0.56] vs 3.34 [0.66]), or global self-worth (mean [SD], 3.42 [0.42] vs 3.69 [0.36]) were found between the amblyopic and control groups.

Conclusions and Relevance

These findings suggest that lower self-perception is associated with slower reading speed and worse motor skills and may highlight the wide-ranging effects of altered visual development for children with amblyopia in their everyday lives.

Binocular amblyopia treatment with contrast-rebalanced movies

BACKGROUND

Binocular amblyopia treatments promote visual acuity recovery and binocularity by rebalancing the signal strength of dichoptic images. Most require active participation by the amblyopic child to play a game or perform a repetitive visual task. The purpose of this study was to investigate a passive form of binocular treatment with contrast-rebalanced dichoptic movies.

METHODS

A total of 27 amblyopic children, 4-10 years of age, wore polarized glasses to watch 6 contrast-rebalanced dichoptic movies on a passive 3D display during a 2-week period. Amblyopic eye contrast was 100%; fellow eye contrast was initially set to a lower level (20%-60%), which allowed the child to overcome suppression and use binocular vision. Fellow eye contrast was incremented by 10% for each subsequent movie. Best-corrected visual acuity, random dot stereoacuity, and interocular suppression were measured at baseline and at 2 weeks.

RESULTS

Amblyopic eye best-corrected visual acuity improved from 0.57 ± 0.22 at baseline to 0.42 ± 0.23 logMAR (t₂₆ = 8.09; P < 0.0001; 95% CI for improvement, 0.11-0.19 logMAR). Children aged 3-6 years had more improvement (0.21 ± 0.11 logMAR) than children aged 7-10 years (0.11 ± 0.06 logMAR; t₂₅ = 3.05; P = 0.005). Children with severe amblyopia (≥0.7 logMAR) at baseline experienced greater improvement (0.24 ± 0.12 logMAR) than children with moderate amblyopia at baseline (0.12 ± 0.06 logMAR; t₂₅ = 3.49; P = 0.002).

CONCLUSIONS

In this cohort, passive viewing of contrast-rebalanced dichoptic movies effectively improved visual acuity in amblyopic subjects. The degree of improvement observed was similar to that previously reported for 2 weeks of binocular games treatment and with 3-4 months of occlusion therapy.

Improved Binocular Outcomes Following Binocular Treatment for Childhood Amblyopia

Purpose

Childhood amblyopia can be treated with binocular games or movies that rebalance contrast between the eyes, which is thought to reduce depth of interocular suppression so the child can experience binocular vision. While visual acuity gains have been reported following binocular treatment, studies rarely report gains in binocular outcomes (i.e., stereoacuity, suppression) in amblyopic children. Here, we evaluated binocular outcomes in children who had received binocular treatment for childhood amblyopia.

Methods

Data for amblyopic children enrolled in two ongoing studies were pooled. The sample included 41 amblyopic children (6 strabismic, 21 anisometropic, 14 combined; age 4–10 years; ≤4 prism diopters [PD]) who received binocular treatment (20 game, 21 movies; prescribed 9–10 hours treatment). Amblyopic eye visual acuity and binocular outcomes (Randot Preschool Stereoacuity, extent of suppression, and depth of suppression) were assessed at baseline and at 2 weeks.

Results

Mean amblyopic eye visual acuity (P < 0.001) and mean stereoacuity improved (P = 0.045), and mean extent (P = 0.005) and depth of suppression (P = 0.003) were reduced from baseline at the 2-week visit (87% game adherence, 100% movie adherence). Depth of suppression was reduced more in children aged <8 years than in those aged ≥8 years (P = 0.004). Worse baseline depth of suppression was correlated with a larger depth of suppression reduction at 2 weeks (P = 0.001).

Conclusions

After 2 weeks, binocular treatment in amblyopic children improved visual acuity and binocular outcomes, reducing the extent and depth of suppression and improving stereoacuity. Binocular treatments that rebalance contrast to overcome suppression are a promising additional option for treating amblyopia.

Slow reading in children with anisometropic amblyopia is associated with fixation instability and increased saccades

BACKGROUND

Previous studies show slow reading in strabismic amblyopia. We recently identified amblyopia, not strabismus, as the key factor in slow reading in children. No studies have focused on reading in amblyopic children without strabismus. We examined reading in anisometropic children and evaluated whether slow reading was associated with ocular motor dysfunction in children with amblyopia.

METHODS

Anisometropic children (7-12 years) with or without amblyopia were compared to age-similar normal controls. Children silently read a grade-appropriate paragraph during binocular viewing. Reading rate (words/min), number of forward and regressive saccades (per 100 words) and fixation duration were recorded with the ReadAlyzer. Binocular fixation instability was also evaluated (EyeLink 1000).

RESULTS

Amblyopic anisometropic children read more slowly (n = 25; mean with standard deviation, 149 ± 42 words/min) than nonamblyopic anisometropic children (n = 15; 196 ± 80 words/min; P = 0.024) and controls (n = 25; 191 ± 65 words/min; P = 0.020). Nonamblyopic anisometropic children read at a comparable rate to controls (P = 0.81). Slow reading in amblyopic anisometropic children was correlated with increased forward saccades (r = -0.84, P < 0.001), increased regressive saccades (r = -0.85, P < 0.001), and fellow eye instability during binocular viewing (r = -0.52, P = 0.019).

CONCLUSIONS

Slow reading in school-age children with anisometropic amblyopia is related to increased frequency of saccades and fixation instability of the fellow eye. Further research should consider the effects of slower reading on academic performance.

Binocular iPad Game vs Patching for Treatment of Amblyopia in Children: A Randomized Clinical Trial

Importance

Fellow eye patching has long been the standard treatment for amblyopia, but it does not always restore 20/20 vision or teach the eyes to work together. Amblyopia can be treated with binocular games that rebalance contrast between the eyes so that a child may overcome suppression. However, it is unclear whether binocular treatment is comparable to patching in treating amblyopia.

Objectives

To assess the effectiveness of a binocular iPad (Apple Inc) adventure game as amblyopia treatment and compare this binocular treatment with patching, the current standard of care.

Design, Setting, and Participants

This investigation was a randomized clinical trial with a crossover design at a nonprofit eye research institute. Between February 20, 2015, and January 4, 2016, a total of 28 patients were enrolled in the study, with 14 randomized to binocular game treatment and 14 to patching treatment.

Interventions

Binocular game and patching as amblyopia treatments.

Main Outcomes and Measures

The primary outcome was change in amblyopic eye best-corrected visual acuity (BCVA) at the 2-week visit. Secondary outcomes were change in stereoacuity and suppression at the 2-week visit and change in BCVA at the 4-week visit.

Results

Among 28 children, the mean (SD) age at baseline was 6.7 (1.4) years (age range, 4.6-9.5 years), and 7 (25%) were female. At baseline, the mean (SD) amblyopic eye BCVA was 0.48 (0.14) logMAR (approximately 20/63; range, 0.3-0.8 logMAR [20/40 to 20/125]), with 14 children randomized to the binocular game and 14 to patching for 2 weeks. At the 2-week visit, improvement in amblyopic eye BCVA was greater with the binocular game compared with patching, with a mean (SD) improvement of 0.15 (0.08) logMAR (mean [SD], 1.5 [0.8] lines) vs 0.07 (0.08) logMAR (mean [SD], 0.7 [0.8] line; P = .02) after 2 weeks of treatment. These improvements from baseline were significant for the binocular game (mean [SD] improvement, 1.5 [0.8] lines; P < .001) and for patching (mean [SD] improvement, 0.7 [0.8] line; P = .006). Depth of suppression improved from baseline at the 2-week visit for the binocular game (mean [SD], 4.82 [2.82] vs 3.24 [2.87]; P = .03) and for patching (mean [SD], 4.77 [3.10] vs 2.57 [1.67]; P = .004). Patching children crossed over to binocular game treatment, and all 28 children played the game for another 2 weeks. At the 4-week visit, no group difference was found in BCVA change, with children who crossed over to the binocular games catching up with children treated with binocular games, for a mean (SD) improvement of 0.17 (0.10) logMAR (mean [SD], 1.7 [1.0] lines) for the binocular game vs a mean (SD) improvement of 0.16 (0.12) logMAR (mean [SD], 1.6 [1.2] lines) for the patching crossover (P = .73).

Conclusions and Relevance

A binocular iPad game was effective in treating childhood amblyopia and was more efficacious than patching at the 2-week visit. Binocular games that rebalance contrast to overcome suppression are a promising additional option for treating amblyopia.

Trial Registration

clinicaltrials.gov Identifier: NCT02365090.

Beyond screening for risk factors: objective detection of strabismus and amblyopia

IMPORTANCE

Commercially available automated vision screening devices assess refractive risk factors, not amblyopia or strabismus, underreferring affected children and overreferring healthy children. Nearly half of affected children are not identified until after age 5 years, when treatment is less effective.

OBJECTIVES

To determine the diagnostic accuracy of the Pediatric Vision Scanner (PVS), a binocular retinal birefringence scanner, to objectively identify strabismus and amblyopia, and to compare retinal birefringence screening with a widely used automated pediatric screening device.

DESIGN, SETTING, AND PARTICIPANTS

Three hundred consecutive preschool children (aged 2-6 years) were screened using the PVS and the SureSight Autorefractor at 2 pediatric ophthalmology private practices. A masked comprehensive pediatric ophthalmic examination provided the gold standard for determining sensitivity and specificity for each screening device.

MAIN OUTCOMES AND MEASURES

The primary outcome was sensitivity and specificity of the PVS for detecting the targeted conditions, strabismus and amblyopia, in children aged 2 to 6 years. Secondary outcomes included the positive and negative likelihood ratios of the PVS for identifying the targeted conditions. In addition, sensitivity, specificity, and positive and negative likelihood ratios of the SureSight Autorefractor for the targeted conditions were assessed in the same cohort of children.

RESULTS

Of the 300 patients, 188 had strabismus only, amblyopia only, or both, and 112 had no strabismus or amblyopia. The sensitivity of the PVS to detect strabismus and amblyopia (0.97; 95% CI, 0.94-1.00) was significantly higher than that of the SureSight Autorefractor (0.74; 95% CI, 0.66-0.83). Specificity of the PVS for strabismus and amblyopia (0.87; 95% CI, 0.80-0.95) was significantly higher than that of the SureSight Autorefractor (0.62; 95% CI, 0.50-0.73).

CONCLUSIONS AND RELEVANCE

The PVS identified children with strabismus and/or amblyopia with high sensitivity, outperforming the SureSight Autorefractor. Accurate, early detection of these conditions could improve long-term vision outcomes of affected preschool children.

Visual acuity deficits in children with nystagmus and Down syndrome

PURPOSE

To investigate the association between visual acuity deficits and fixation instability in children with Down syndrome and nystagmus.

DESIGN

Prospective cross-sectional study.

METHODS

setting: Institutional. study population:Sixteen children (aged 10 months-14 years) with Down syndrome and nystagmus, and a control group of 93 age-similar children with unassociated infantile nystagmus. observation procedures: Binocular Teller acuity card testing and eye-movement recordings. Fixation stability was quantified using the nystagmus optimal fixation function (NOFF). An exponential model based on results from the control group with unassociated infantile nystagmus was used to relate fixation stability to age-corrected visual acuity deficits. main outcome measures: Binocular grating visual acuity and NOFF.

RESULTS

Visual acuity was 0.2-0.9 logMAR (20/30-20/174 Snellen equivalent) and corresponded to a 0.4 logMAR (4 lines) mean age-corrected visual acuity deficit. Fixation stability ranged from poor to mildly affected. Although visual acuity deficit was on average 0.17 logMAR larger (P = .005) than predicted by the model, most children had visual acuity deficit within the 95% predictive interval.

CONCLUSIONS

There was a small mean difference between the measured visual acuity deficit and the prediction of the nystagmus model. Although other factors also contribute to visual acuity loss in Down syndrome, nystagmus alone could account for most of the visual acuity deficit in these children.

Inhibitors of collagenase but not of gelatinase reduce cartilage explant proteoglycan breakdown despite only low levels of matrix metalloproteinase activity

Aims-To investigate the level of matrix metalloproteinase activity during the time-course of cartilage explant proteoglycan breakdown; to determine the effects of selective small-molecule inhibitors of matrix metalloproteinases on proteoglycan degradation.Methods-The levels of matrix metalloproteinase activity in cartilage explant cultures and conditioned media were monitored by use of a quenched fluorescent substrate. The constants for inhibition of certain matrix metalloproteinases by a series of synthetic inhibitors were determined. Bovine and human cartilage explant cultures were treated with interleukin-1, tumor necrosis factor or retinoic acid and the amount of proteoglycan released into the culture medium in the absence and presence of the inhibitors was quantified. Control experiments, examining the inhibition of other proteinases, and investigating possible toxic or non-specific effects of the inhibitors, were carried out.Results-The profile of inhibition of proteoglycan release suggested the involvement of interstitial collagenase-like, rather than gelatinase- or possibly stromelysin-like, proteinases. No evidence was found for toxic or non-specific mechanisms of inhibition. Very low levels of activity of the known matrix metalloproteinases were present during the time-course of aggrecan breakdown.Conclusions-A novel collagenase-like proteinase(s) may be involved in cartilage proteoglycan breakdown. Gelatinase-type matrix metalloproteinases do not seem to be involved in this process. Specific collagenase inhibitors may be therapeutically efficacious in the treatment of arthritis.

The economic value added (EVA) resulting from medical care of functional amblyopia, strabismus, (pathologies of binocular vision) and asthma

INTRODUCTION

Value analysis in health care calculates the economic value added (EVA) that results from improvements in health and health care. Our purpose was to develop an EVA model and to apply the model to typical and hypothetical (instantaneous and perfect) cures for amblyopia, surgical strabismus and asthma, as another, but non-ophthalmological disease standard for comparison, in the United States.

METHODS

The model is based on changes in utility and longevity, the associated incremental costs, and an estimate of the value of life. Univariate sensitivity analyses were performed to arrive at a plausible range of outcomes.

RESULTS

For the United States, the EVA for current practice amblyopia care is 12.9B dollars (billion) per year, corresponding to a return on investment (ROI) of 10.4% per yr. With substantial increases in investment aimed at maximal improvement ("perfect cure"), the EVA is 32.7B per yr, with ROI of 5.3% per yr. The EVA for typical surgical strabismus care is 10.3B per yr. A perfect cure may yield EVA of 9.6B per yr. The EVA for asthma is 1317B per yr (ROI 20.4% per yr.., while a perfect cure may yield EVA of 110 B per yr. Sensitivity analysis demonstrated the relatively large effects of incidence, utility, and longevity, while incremental costs have a relatively minor effect on the EVA.

CONCLUSION

The economic value added by improvements in patient-centered outcomes is very large. Failing to make the necessary investments in research, prevention, detection, prompt treatment and rehabilitation of these diseases, at virtually any conceivable cost, appears economically, medically, morally and ethically deficient and consequently wasteful at very least economically for our society.

Surgical findings with the tinted AcrySof intraocular lens in children

INTRODUCTION

The AcrySof foldable acrylic intraocular lens (IOL) has become an accepted and frequent means of treating pediatric aphakia. A new version of this lens with blue-light filtering properties purports to offer superior retinal protection. We describe our experience with this tinted lens and compare it to findings with the standard, nontinted IOL.

METHODS

A chart review identified 29 eyes of 21 children (tinted lens group; age 11 months to 13 years) who had the tinted IOL implanted. The standard lens group consisted of 38 eyes (31 patients; age 11 months to 15 years). Most eyes had an intact posterior capsule at the time of implantation.

RESULTS

The incidence of postoperative inflammation was fairly high in both groups (71% in the tinted lens group, 60% in the standard lens group). The tinted lens group showed a higher incidence of transient inflammation than the standard lens group (p=0.03) but the rates of nontransient sequelae (posterior synechiae, iris synechiae, membranes formation, capsule, or IOL opacification) were similar (66% versus 47%; p=0.11). Posterior capsule opacification occurred in 15 eyes in the tinted lens group and 16 eyes in the standard lens group (p=0.15) but was visually significant in only 10 and 11 eyes, respectively (p=0.77).

CONCLUSIONS

Transient inflammation is higher with implantation of tinted versus nontinted IOLs, but long-term inflammatory sequelae are roughly equal, as is the rate of posterior capsule opacification. The question as to whether the chromophore in the tinted lens caused the higher incidence of transient inflammation is unresolved.

The cost utility of strabismus surgery in adults

PURPOSE

Cost-utility analysis evaluates the cost of medical care in relation to the gain in quality-adjusted life years (QALYs). Our purpose was to develop a cost model for surgical care for adult strabismus, to estimate the mean cost per case, to determine the associated gain in QALYs, and to perform cost-utility analysis.

METHODS

A cost model incorporated surgery, pre- and postoperative care, and a mean of 1.5 procedures per patient. The gain in QALYs was based on the improvement of utility on a scale from 0 (death) to 1 (perfect health). Utility was measured through physician-conducted interviews employing a time tradeoff question (seeking to estimate the portion of life expectancy a patient would be willing to trade for being rid of disease and associated effects). The interviews were conducted before and 5 to 8 weeks after surgery in 35 strabismic patients (age 19-75 years).

RESULTS

The cost model resulted in an estimated total cost of 4,254 dollars per case. A significant improvement of utility was found: 0.96 +/- 0.11 postoperatively versus 0.85 +/- 0.20 preoperatively (p = 0.00008). Based on the mean life expectancy (36.0 years) of these patients, and discounting outcomes and costs by 3% annually, this resulted in a mean value gain of 2.61 QALYs after surgery and a cost-utility for strabismus surgery of 1,632 dollas/QALY.

CONCLUSIONS

In the United States, treatments <50,000 dollars/QALY are generally considered "very cost-effective." Strabismus surgery in adults falls well within this range.

The utility of strabismus in adults

PURPOSE

To determine the utility (quality-of-life weight) associated with adult strabismus.

METHODS

Time tradeoff utility values were measured in physician-conducted interviews with 140 adult patients with strabismus in a private practice setting. Patients also completed a questionnaire containing six items that rated the following aspects of disability: specific health problems, problems with tasks of daily living, problems with social interaction, self-image problems, concerns about the future, and job-related problems. Patients were characterized as presurgical or nonsurgical, and their diplopia and asthenopia were rated by the physician on a four-level scale.

RESULTS

About 60% of all patients indicated willingness to trade part of their life expectancy in return for being rid of strabismus and its associated effects. The median utility was 0.93 (interquartile range, 0.83 to 1.0). A significantly smaller proportion (44%) of the nonsurgical patients (N = 41) appeared willing to trade time compared with surgical patients (68%; P = .009). Median utility in the presurgical patients was 0.90. Strong relationships were found between utility and the level of diplopia (P < .0001), and between utility and the level of asthenopia (P < .0001). Utility was correlated with all six disability ratings (all P < or = .00062).

CONCLUSION

A majority of the patients interviewed would trade a portion of their life expectancy in return for being rid of strabismus and its associated effects. These results were validated by significant associations with diplopia, asthenopia, and disability.

Lymphocytic choriomeningitis virus: emerging fetal teratogen

Lymphocytic choriomeningitis virus (LCMV), a rodent-borne arenavirus, is an often undiagnosed human fetal teratogen. We describe a neonate born with hydrocephalus and chorioretinitis after maternal second-trimester symptomatic LCMV infection. Previously reported affected infants are reviewed. We strongly suggest that obstetricians counsel their pregnant patients regarding the potential hazard that contact with infected pet, laboratory, and household mice and hamsters poses to pregnant women and their unborn children.