Why worry with friends? Problem talk and anxiety in late adolescent friendships.

INTRODUCTION: This study investigated a theoretically derived peer conversation style, problem anxiety talk, to examine the emotional regulation of anxiety in dyads as a possible mechanism of anxiety contagion that occurs between adolescent friends. METHODS: In Study 1, 376 late adolescents residing in the United States, ages 17-24 with 68% female, responded to measures of anxiety, worry, friendship quality, depression, co-rumination, and a new measure of problem anxiety talk. In Study 2 problem anxiety talk, stress, anxiety and depression were evaluated in 481 late adolescents, ages 17-24 with 64% female. RESULTS: Once controlling for worry and co-rumination, problem anxiety talk with a close friend predicted anxiety, stress and depression for both samples of late adolescents. Factor analysis in each sample supported problem anxiety talk as a single factor with high internal consistency. CONCLUSIONS: Findings indicate that problem anxiety talk is a distinct construct representing interpersonal disclosures between friends involving threat perception, likelihood of negative events, and lack of coping skills; results also indicate that problem anxiety talk is associated with anxiety, stress, worry, and depression. Implications of problem anxiety talk in its potential role in the etiology and spread of anxiety are discussed.

Intervention Adherence and Self-Efficacy as Predictors of Child Outcomes in School Nurse-Delivered Interventions for Anxiety.

This study examined the association between two implementation factors, nurse-reported intervention adherence and self-efficacy, and children's outcomes in school nurse-delivered anxiety interventions. Data were collected in a pilot randomized controlled effectiveness trial with 54 children and 21 school nurses. Nurses implemented either a cognitive behavioral or relaxation-skills-only intervention. Nurse questionnaires assessed implementation factors. Independent evaluators assessed changes in children's anxiety symptoms at postintervention and at 3-month follow-up using clinical improvement and global functioning scales. Regression analyses indicated that greater intervention adherence was associated with greater anxiety symptom improvement at follow-up. Nurse self-efficacy interacted with intervention group, such that nurses with higher self-efficacy who implemented the cognitive behavioral intervention tended to have children show improvement and higher postintervention functioning. The impact of implementation factors on children's outcomes may differ depending on intervention type. Self-efficacy may be important for nurses using relatively complex interventions. Intervention adherence should be supported through training and consultation.

A pilot RCT of a school nurse delivered intervention to reduce student anxiety.

The goal of this study was to evaluate the feasibility and impact of brief school-nurse-administered interventions for reducing anxiety. Thirty school nurses in Connecticut and Maryland were randomly assigned to deliver the Child Anxiety Learning Modules (CALM; n = 14) or CALM-Relaxation only (CALM-R; n = 16). Students (N = 54) were ages 5-12 (M age = 8; 84.9% White; 68.5% female) with elevated anxiety symptoms and/or anxiety disorders. Feasibility was assessed based on recruitment, retention, attendance, training and intervention satisfaction, and intervention adherence. Multiple informants, including independent evaluators (IEs), completed measures of clinical improvement at postintervention and at a 3-month follow-up. Of nurses in CALM and CALM-R, 62% and 81%, respectively, enrolled a student and completed an average of 6 sessions. Youth retention was 85% and 94% in CALM and CALM-R, respectively. Training and intervention satisfaction were high. At postintervention and follow-up, youth in both groups showed significant reductions in anxiety and related symptoms and improvements in functioning. Within-group effect sizes were medium to large, and between-group effect sizes were small. Task shifting responsibility for delivering brief mental health interventions to school nurses is feasible and shows promise for reducing anxiety and related impairment. This approach may also be integrated within a response to intervention model used in schools.Public Health Significance: Brief school-nurse-administered anxiety reduction interventions were shown to be feasible and had a positive impact on student anxiety and related impairment highlighting that school nurses can be an important school resource.

Long-term no-till and stover retention each decrease the global warming potential of irrigated continuous corn.

Over the last 50 years, the most increase in cultivated land area globally has been due to a doubling of irrigated land. Long-term agronomic management impacts on soil organic carbon (SOC) stocks, soil greenhouse gas (GHG) emissions, and global warming potential (GWP) in irrigated systems, however, remain relatively unknown. Here, residue and tillage management effects were quantified by measuring soil nitrous oxide (N2 O) and methane (CH4 ) fluxes and SOC changes (ΔSOC) at a long-term, irrigated continuous corn (Zea mays L.) system in eastern Nebraska, United States. Management treatments began in 2002, and measured treatments included no or high stover removal (0 or 6.8 Mg DM ha-1  yr-1 , respectively) under no-till (NT) or conventional disk tillage (CT) with full irrigation (n = 4). Soil N2 O and CH4 fluxes were measured for five crop-years (2011-2015), and ΔSOC was determined on an equivalent mass basis to ~30 cm soil depth. Both area- and yield-scaled soil N2 O emissions were greater with stover retention compared to removal and for CT compared to NT, with no interaction between stover and tillage practices. Methane comprised <1% of total emissions, with NT being CH4 neutral and CT a CH4 source. Surface SOC decreased with stover removal and with CT after 14 years of management. When ΔSOC, soil GHG emissions, and agronomic energy usage were used to calculate system GWP, all management systems were net GHG sources. Conservation practices (NT, stover retention) each decreased system GWP compared to conventional practices (CT, stover removal), but pairing conservation practices conferred no additional mitigation benefit. Although cropping system, management equipment/timing/history, soil type, location, weather, and the depth to which ΔSOC is measured affect the GWP outcomes of irrigated systems at large, this long-term irrigated study provides valuable empirical evidence of how management decisions can impact soil GHG emissions and surface SOC stocks.

Manure and Inorganic Nitrogen Affect Trace Gas Emissions under Semi-Arid Irrigated Corn.

Dairy manure is often applied to cropped soils as a substitute for inorganic N fertilizers, but the impacts of manure on soil trace gas fluxes, yields, and soil N are uncertain in the semiarid western United States. Soil carbon dioxide (CO-C), methane (CH-C), nitrous oxide (NO-N), and ammonia (NH-N) emissions were monitored using surface chambers from five N treatments: (i) partially composted solid dairy manure (DM) (412 kg N ha), (ii) DM + AgrotainPlus (DM+AP), (iii) enhanced efficiency N fertilizer (SuperU [SU]) (179 kg N ha), (iv) urea (179 kg N ha), and (v) check (no N applied), to determine their effect on growing season (GS) and nongrowing season emissions from a tilled clay loam soil under irrigated, continuous corn production for 3 yr. SuperU and AgrotainPlus contain urease and nitrification inhibitors. Averaged over years, GS soil CO-C emissions were greater for DM and DM+AP than for urea, SU, and check treatments due to the large amount of C added with the manure; CH-C emissions did not vary among N treatments; and NO-N emissions decreased in the order urea = DM = DM+AP > SU > check. AgrotainPlus added to the DM did not reduce NO-N emissions compared with DM. Cumulative NH-N emissions after manure application decreased in the order urea > SU > check, with no significant differences between SU, DM, and DM+AP. Dairy manure provided slow-release N with nitrate intensities lower than urea and NO-N emissions similar to urea. These results highlight the importance of best-management practices such as immediate irrigation after N application and use of urease and nitrification inhibitors to minimize N losses.

Consultants' perceptions of school counselors' ability to implement an empirically-based intervention for adolescent social anxiety disorder.

Social anxiety is highly prevalent but goes untreated. Although school-based CBT programs are efficacious when delivered by specialized psychologists, it is unclear whether school counselors can implement these interventions effectively, which is essential to promote sustainable school programs. We present an initial consultation strategy to support school counselor implementation of group CBT for social anxiety and an evaluation of counselors' treatment fidelity. Counselors were highly adherent to the treatment, but competence varied based on measurement. Counselors and consultants demonstrated good agreement for adherence, but relatively modest correspondence in competence ratings. We discuss future directions for school-based implementation efforts informed by these initial findings.

High N availability decreases N uptake and yield under limited water availability in maize.

Water and nitrogen (N) are the most limiting factors to plant productivity globally, but we lack a critical understanding of how water availability impacts N dynamics in agricultural systems. Plant N requirements are particularly uncertain when water is limited because of the interactive effect of water and N on plant growth, N demand, and plant uptake. We investigated impacts of N application and water availability on plant growth and N movement, including above and belowground growth, water productivity, N productivity, N uptake, N recovery, and greenhouse gas emissions within a semi-arid system in northeastern Colorado, USA. Moderately high soil N availability depressed grain yield and shoot growth under both limited and full water availability, despite no indication of physical toxicity, and came with additional risk of deleterious N losses. Under low N availability, plant N concentrations in aboveground tissues showed greater recovery of N than what was applied in the low N treatments under both full and limited water availability. This enhanced recovery underscores the need to better understand both plant soil foraging and processes governing resource availability under these conditions. Finally, limited water availability reduced N uptake across all N treatments and left 30% more soil nitrate (NO3-) deep in the soil profile at the end of the season than under full water availability. Our results show that plant N needs are not linearly related to water use and emphasize the need for an integrated understanding of water and N interactions, plant foraging for these resources, and the dynamics of processes that make N available to plants.

Biochar and nitrogen fertilizer alters soil nitrogen dynamics and greenhouse gas fluxes from two temperate soils.

Biochar (BC) application to agricultural soils could potentially sequester recalcitrant C, increase N retention, increase water holding capacity, and decrease greenhouse gas (GHG) emissions. Biochar addition to soils can alter soil N cycling and in some cases decrease extractable mineral N (NO and NH) and NO emissions. These benefits are not uniformly observed across varying soil types, N fertilization, and BC properties. To determine the effects of BC addition on N retention and GHG flux, we added two sizes (>250 and <250 µm) of oak-derived BC (10% w/w) to two soils (aridic Argiustoll and aquic Haplustoll) with and without N fertilizer and measured extractable NO and NH and GHG efflux (NO, CO, and CH) in a 123-d laboratory incubation. Biochar had no effect on NO, NH, or NO in the unfertilized treatments of either soil. Biochar decreased cumulative extractable NO in N fertilized treatments by 8% but had mixed effects on NH. Greenhouse gas efflux differed substantially between the two soils, but generally with N fertilizer BC addition decreased NO 3 to 60%, increased CO 10 to 21%, and increased CH emissions 5 to 72%. Soil pH and total treatment N (soil + fertilizer + BC) predicted soil NO flux well across these two different soils. Expressed as CO equivalents, BC significantly reduced GHG emissions only in the N-fertilized silt loam by decreasing NO flux. In unfertilized soils, CO was the dominant GHG component, and the direction of the flux was mediated by positive or negative BC effects on soil CO flux. On the basis of our data, the use of BC appears to be an effective management strategy to reduce N leaching and GHG emissions, particularly in neutral to acidic soils with high N content.

Deficit irrigation impacts on greenhouse gas emissions under drip-fertigated maize in the Great Plains of Colorado.

Precise water and fertilizer application can increase crop water productivity and reduce agricultural contributions to greenhouse gas (GHG) emissions. Regulated deficit irrigation (DI) and drip fertigation control the amount, location, and timing of water and nutrient application. Yet, few studies have measured GHG emissions under these practices, especially for maize (Zea mays L.). The objective was to quantify N2 O and CO2 emission from DI and full irrigation (FI) within a drip-fertigated maize system in northeastern Colorado. During two growing seasons of measurement, treatments consisted of mild, moderate, and extreme DI and FI. Deficit irrigation was managed based on growth stage so that full evapotranspiration (ET) was met during the yield-sensitive reproductive stage, but less than full crop ET was applied during the late vegetative and maturation growth stages. In the first year, mild DI (90% ET) reduced N2 O emissions by 50% compared with FI. In the second year, compared with FI, moderate DI (69-80% ET) reduced N2 O emissions by 15%, and extreme DI (54-68% ET) reduced N2 O emissions by 40%. Only extreme DI in the second year significantly reduced CO2 emissions (by 30%) compared with FI. Mild DI reduced yield-scaled emissions in the first year, but moderate and extreme DI had similar yield-scaled emissions as FI in the second year. The surface drip fertigation resulted in total GHG emissions that were one-tenth of literature-based measurements from sprinkler-irrigated maize systems. This study illustrates the potential of DI and drip fertigation to reduce N2 O and CO2 emissions in irrigated cropping systems.

Soil organic carbon response to global environmental change depends on its distribution between mineral-associated and particulate organic matter: A meta-analysis.

Soil organic carbon (SOC), as the largest terrestrial carbon pool, plays an important role in global carbon (C) cycling, which may be significantly impacted by global changes such as nitrogen (N) fertilization, elevated carbon dioxide (CO2), warming, and increased precipitation. Yet, our ability to accurately detect and predict the impact of these global changes on SOC dynamics is still limited. Investigating SOC responses to global changes separately for mineral-associated organic carbon (MAOC) and the particulate organic carbon (POC) can aid in the understanding of overall SOC responses, because these are formed, protected, and lost through different pathways. To this end, we performed a systematic meta-analysis of the response of SOC, MAOC, and POC to global changes. POC was particularly responsive, confirming that it is a better diagnostic indicator of soil C changes in the short-term, compared to bulk SOC and MAOC. The effects of elevated CO2 and warming were subtle and evident only in the POC fraction (+5.11% and - 10.05%, respectively), while increased precipitation had no effects at all. Nitrogen fertilization, which comprised the majority of the dataset, increased SOC (+5.64%), MAOC (+4.49%), and POC (+13.17%). Effect size consistently varied with soil depth and experiment length, highlighting the importance of long-term experiments that sample the full soil profile in global change SOC studies. In addition, SOC pool responses to warming were modified by degree of warming, differently for air and soil warming manipulations. Overall, we suggest that MAOC and POC respond differently to global changes and moderators because of the different formation and loss processes that control these pools. Coupled with additional plant and microbial measurements, studying the individual responses of POC and MAOC improves understanding of the underlying dynamics of SOC responses to global change. This will help inform the role of SOC in mitigating the climate crisis.

The optical treatment of amblyopia.

The role of refractive correction has been underestimated as a distinct component of amblyopia therapy. Until relatively recently, the extent to which it could ameliorate the amblyopic acuity deficit remained unquantified and the time course of its effect unknown. Improvement of vision after refractive correction appears to occur in all the major types of amblyopia, including, somewhat surprisingly, in the presence of strabismus. Although the neurophysiological basis of the remediative effect of such "optical treatment" is unknown, some insight is now available from animal models and psychophysical investigations in humans. An appreciation of the role that refractive correction can play in the overall management of amblyopia has led to the formulation of new treatment guidelines, whereby a defined period of spectacle or contact lens wear always precedes traditional therapies, such as occlusion or penalization.

Management controls the net greenhouse gas outcomes of growing bioenergy feedstocks on marginally productive croplands.

Bio-based energy is key to developing a globally sustainable low-carbon economy. Lignocellulosic feedstock production on marginally productive croplands is expected to provide substantial climate mitigation benefits, but long-term field research comparing greenhouse gas (GHG) outcomes during the production of annual versus perennial crop-based feedstocks is lacking. Here, we show that long-term (16 years) switchgrass (Panicum virgatum L.) systems mitigate GHG emissions during the feedstock production phase compared to GHG-neutral continuous corn (Zea mays L.) under conservation management on marginally productive cropland. Increased soil organic carbon was the major GHG sink in all feedstock systems, but net agronomic GHG outcomes hinged on soil nitrous oxide emissions controlled by nitrogen (N) fertilizer rate. This long-term field study is the first to demonstrate that annual crop and perennial grass systems respectively maintain or mitigate atmospheric GHG contributions during the agronomic phase of bioenergy production, providing flexibility for land-use decisions on marginally productive croplands.

Modeling dose-response in amblyopia: toward a child-specific treatment plan.

PURPOSE: This article describes an empirically derived mathematical model of the treatment dose-response of occlusion therapy for amblyopia based on outcome data obtained from the Monitored Occlusion Treatment for Amblyopia Study (MOTAS). METHODS: The MOTAS protocol comprised three discrete phases: baseline, refractive adaptation, and occlusion. Only data from the occlusion phase were used in this dose-response model. Seventy-two participants, 3 to 8 years of age, mean +/- SD age 5.2 +/- 1.4 years (anisometropia [n = 18]); strabismus [n = 22]); both anisometropia and strabismus [n = 32]) completed the occlusion phase. All participants were prescribed 6-h/d patching, which was objectively monitored by an occlusion dose monitor (ODM). RESULTS: Simple normal linear regression modeling of the data on an interval-by-interval basis (interval between clinic visits) indicates that increasing cumulative dose within interval (hours) yields an increase in visual acuity (R2 = 0.918; 684 data points). Most of the children achieved their best visual acuity with 150 to 250 hours' cumulative dose. Specific patient characteristics (especially age) modify the steepness of this function. For example, a 0.20-logMAR (2-line logarithm of the minimum angle of resolution) gain in visual acuity requires a cumulative dose of 170 hours for children at age 48 months and 236 hours at age 72 months. CONCLUSIONS: Mathematical modeling of amblyopia therapy is a novel approach that elucidates the kinetics of the therapeutic response in humans. This response is age-influenced so that older children require a greater dose to achieve the same outcome--evidence of altered plasticity of the visual system. Fine-tuning the dose-response in amblyopia therapy will facilitate the development of child-specific, evidence-based treatment plans.

Occlusion dose monitoring in amblyopia therapy: status, insights, and future directions.

Occlusion therapy remains the mainstay treatment of amblyopia, but its outcome is not assured or universally excellent. Many factors are known to influence treatment outcome, among which compliance is foremost. The occlusion dose monitor (ODM) removes one variable from the treatment equation, because it records the occlusion actually received by-rather than prescribed for-the child. Improvement observed can thus be quantitatively related to the patching received. This review summarizes the insights the ODM has provided to date particularly in elucidating the dose-response relationship. We are entering the era of personalized ophthalmology in which treatments will be tailored to the needs of the individual child and facilitated by the use of wearable monitors.

Paediatric Eye Services: How Much of the Workload Is Amblyopia-Related?

AIMS: The proportion of patients seen by the paediatric eye service that attend for reasons related to amblyopia has not been quantified. The purpose of this study was to quantify the proportion of patients seen in the paediatric eye service attending for reasons related to amblyopia. METHODS: Records of all eye appointments of children attending the Hillingdon Hospitals NHS Foundation Trust and St Mary's Hospital Imperial College Healthcare NHS Trust over one month in 2009 were examined to determine the diagnosis and reason for attendance. RESULTS: Seven hundred and four patients had appointments booked at St Mary's and Hillingdon in March 2009. The fail-to-attend rates were not significantly different at the 2 sites (19% at St Mary's and 9% at Hillingdon; P=0.75). Of the 704 patients, 533 (St Mary's, 252 [75%]; Hillingdon, 281 [76%]) were attending for amblyopia-related reasons. Of the overall 982 booked appointments, 770 (79%) were amblyopia-related. CONCLUSIONS: Amblyopia diagnosis and management is clearly the most common cause of attendance to the paediatric eye service, accounting for over three-quarters of outpatient visits.

Treatment of Amblyopia Using Personalized Dosing Strategies: Statistical Modelling and Clinical Implementation.

PURPOSE: To generate a statistical model for personalizing a patient's occlusion therapy regimen. METHODS: Statistical modelling was undertaken on a combined data set of the Monitored Occlusion Treatment of Amblyopia Study (MOTAS) and the Randomized Occlusion Treatment of Amblyopia Study (ROTAS). This exercise permits the calculation of future patients' total effective dose (TED)-that predicted to achieve their best attainable visual acuity. Daily patching regimens (hours/day) can be calculated from the TED. RESULTS: Occlusion data for 149 study participants with amblyopia (anisometropic in 50, strabismic in 43, and mixed in 56) were analyzed. Median time to best observed visual acuity was 63 days (25% and 75% quartiles; 28 and 91 days). Median visual acuity in the amblyopic eye at start of occlusion was 0.40 logMAR (quartiles 0.22 and 0.68 logMAR) and at end of occlusion was 0.12 (quartiles 0.025 and 0.32 logMAR). Median lower and upper estimates of TED were 120 hours (quartiles 34 and 242 hours), and 176 hours (quartiles 84 and 316 hours). The data suggest a piecewise linear relationship (P = 0.008) between patching dose-rate (hours/day) and TED with a single breakpoint estimated at 2.16 (standard error 0.51) hours/day, suggesting doses below 2.16 hours/day are less effective. CONCLUSION: We introduce the concept of TED of occlusion. Predictors for TED are visual acuity deficit, amblyopia type, and age at start of occlusion therapy. Dose-rates prescribed within the model range from 2.5 to 12 hours/day and can be revised dynamically throughout treatment in response to recorded patient compliance: a personalized dosing strategy.

Treatment of unilateral amblyopia: factors influencing visual outcome.

PURPOSE: To identify factors that influence the outcome of treatment for unilateral amblyopia, as a part of the Monitored Occlusion Treatment of Amblyopia Study (MOTAS). METHODS: This was an intervention study consisting of three nonoverlapping phases: "Baseline", "refractive adaptation" (18 weeks of full-time spectacle wear), and "occlusion" (6 hours of patching per day, objectively monitored). Condition factors: type of amblyopia, age of participant, initial severity of amblyopia, fixation, and binocular vision status; treatment factors: refractive adaptation and occlusion (total dose [hours] and dose rate [hours per day]) were assessed for their influence on visual outcome. Visual outcome was expressed in three ways: logMAR (logarithm of the minimum angle of resolution) change, residual amblyopia, and proportion of the deficit corrected. RESULTS: The study included 85 participants (mean age, 5.1 +/- 1.4 years) with amblyopia associated with strabismus (n = 32) or anisometropia (n = 20) or associated with both anisometropia and strabismus (n = 33). Treatment factors: cumulative occlusion dose exceeding 50 hours, and dose rates > or =1 hour per day resulted in (P < or = 0.01) lower residual amblyopia and a greater proportion of the deficit corrected. Condition factors associated with poor outcome (high residual amblyopia) were presence of eccentric fixation, severe initial amblyopia, and no binocular vision. CONCLUSIONS: Factors influencing outcome with treatment for amblyopia are occlusion dose (the rate of delivery and cumulative dose worn), the initial severity of the amblyopia, binocular vision status, fixation of the amblyopic eye, and the age of the subject at the start of treatment.

Enhancing the Capacity of School Nurses to Reduce Excessive Anxiety in Children: Development of the CALM Intervention.

PROBLEM: Excessive anxiety is among the most common psychiatric problems facing youth. Because anxious youth tend to have somatic complaints, many seek help from the school nurse. Thus, school nurses are in an ideal position to provide early intervention. This study addresses this problem and describes the plans to develop and test a new intervention (Child Anxiety Learning Modules; CALM), delivered by school nurses, to reduce child anxiety and improve academic functioning. METHODS: An iterative development process including consultation with an expert panel, two open trials, and a pilot randomized controlled study comparing CALM to usual care is proposed. Feedback will be solicited from all participants during each phase and data on outcome measures will be provided by children, parents, teachers, and independent evaluators. FINDINGS: Data will be collected on intervention satisfaction and feasibility. Primary outcomes that include child anxiety symptoms, classroom behavior, and school performance (e.g., attendance, grades, standardized test scores) will be collected at pre- and post-interventions and at a 3-month follow-up evaluation. CONCLUSIONS: Pediatric anxiety is a common problem that school nurses frequently encounter. Consequently, they are well positioned to play a key role in enhancing access to behavioral health interventions to reduce anxiety and may therefore make a significant positive public health impact.

Personalized versus standardized dosing strategies for the treatment of childhood amblyopia: study protocol for a randomized controlled trial.

BACKGROUND: Amblyopia is the commonest visual disorder of childhood in Western societies, affecting, predominantly, spatial visual function. Treatment typically requires a period of refractive correction ('optical treatment') followed by occlusion: covering the nonamblyopic eye with a fabric patch for varying daily durations. Recent studies have provided insight into the optimal amount of patching ('dose'), leading to the adoption of standardized dosing strategies, which, though an advance on previous ad-hoc regimens, take little account of individual patient characteristics. This trial compares the effectiveness of a standardized dosing strategy (that is, a fixed daily occlusion dose based on disease severity) with a personalized dosing strategy (derived from known treatment dose-response functions), in which an initially prescribed occlusion dose is modulated, in a systematic manner, dependent on treatment compliance. METHODS/DESIGN: A total of 120 children aged between 3 and 8 years of age diagnosed with amblyopia in association with either anisometropia or strabismus, or both, will be randomized to receive either a standardized or a personalized occlusion dose regimen. To avoid confounding by the known benefits of refractive correction, participants will not be randomized until they have completed an optical treatment phase. The primary study objective is to determine whether, at trial endpoint, participants receiving a personalized dosing strategy require fewer hours of occlusion than those in receipt of a standardized dosing strategy. Secondary objectives are to quantify the relationship between observed changes in visual acuity (logMAR, logarithm of the Minimum Angle of Resolution) with age, amblyopia type, and severity of amblyopic visual acuity deficit. DISCUSSION: This is the first randomized controlled trial of occlusion therapy for amblyopia to compare a treatment arm representative of current best practice with an arm representative of an entirely novel treatment regimen based on statistical modelling of previous trial outcome data. Should the personalized dosing strategy demonstrate superiority over the standardized dosing strategy, then its adoption into routine practice could bring practical benefits in reducing the duration of treatment needed to achieve an optimal outcome. TRIAL REGISTRATION: ISRCTN ISRCTN12292232.

Treatment dose-response in amblyopia therapy: the Monitored Occlusion Treatment of Amblyopia Study (MOTAS).

PURPOSE: Amblyopia is the commonest visual disorder of childhood. Yet the contributions of the two principal treatments (spectacle wear and occlusion) to outcome are unknown. This study was undertaken to investigate the dose-response relationship of amblyopia therapy. METHODS: The study comprised three distinct phases: baseline, in which repeat measures of visual function were undertaken to confirm the initial visual deficit; refractive adaptation: an 18-week period of spectacle wear with six weekly measurements of logarithm of the minimum angle of resolution (logMAR) visual acuity; occlusion: in which participants were prescribed 6 hours of "patching" per day. In the latter phase, occlusion was objectively monitored and logMAR visual acuity recorded at 2-week intervals until any observed gains had ceased. RESULTS: Data were obtained from 94 participants (mean age, 5.1 +/- 1.4 years) with amblyopia associated with strabismus (n = 34), anisometropia (n = 23), and both anisometropia and strabismus (n = 37). Eighty-six underwent refractive adaptation. Average concordance with patching was 48%. The relationship between logMAR visual acuity gain and total occlusion dose was monotonic and linear. Increasing dose rate beyond 2 h/d hastened the response but did not improve outcome. More than 80% of the improvement during occlusion occurred within 6 weeks. Treatment outcome was significantly better for children younger than 4 years (n = 17) than in those older than 6 years (n = 24; P = 0.0014). CONCLUSIONS: Continuous objective monitoring of the amount of patching therapy received has provided insight into the dose-response relationship of occlusion therapy for amblyopia. Patching is most effective within the first few weeks of treatment, even for those in receipt of a relatively small dose. Further studies are needed to elucidate the neural basis for the dose-response functions.