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.     

波前像差检查在远视弱视儿童屈光检测中的应用

目的　探讨波前像差检查在远视、弱视儿童屈光检查中的应用。方法　51例弱视患儿经1%阿托品散瞳3天后进行视网膜检影验光并使用Allegretto波前像差仪进行像差测定。结果　波前像差仪测得的球镜度、柱镜度、散光轴向和视网膜检影验光所测得的球镜度、柱镜度、散光轴向分别为( 2 .11±1. 70)D, ( 1. 44±1 .07)D,78. 82±35. 15,( 2 .12±1 .63)D, ( 2. 29±1. 93)D和75. 41±38. 45。等效球镜值越大,各阶像差值越大(P<0. 05)。矫正视力和二阶像差均方根值(RMS2)和总像差均方根值(RMSg)有关(P<0. 01)。轻度弱视组的高阶像差低于中度弱视组高阶像差。随着散光度的增加,高阶像差中三叶散光、彗差、球差都增加,三叶散光、垂直彗差有统计学意义(P<0.01、P<0. 05)。结论　波前像差检查能较正确地反映远视儿童眼的屈光度,可作为远视儿童屈光检查的一个客观手段。高阶像差分析有助于了解远视儿童弱视的原因。     

脱抑制训练在弱视治疗中的临床观察

目的 观察应用增视训练软件脱抑制训练治疗屈光不正性弱视的临床疗效。方法 应用脱抑制训练联合视觉刺激训练对77例屈光不正性弱视患儿进行治疗。结果 训练5～13次,平均8次,视力提高达≥0．9者25例,占32～46％;训练5～13次,平均7．8次,视力增长2行或2行以上者26例,占33．77％。训练5～13次,平均8.7次,视力不变或提高1行者26例,占33．77％;总有效率占66．23％。结论 应用脱抑制训练治疗屈光不正性弱视不仅有效,而且可以缩短疗程。     

Syndrome of myelinated retinal nerve fibres,myopia, amblyopia and strabismus in a Nigerian

Myelinated retinal nerve fibres (MRNF) are rare congenital anomalies. They may present in a syndrome characterised by ipsilateral myelinated retinal nerve fibres, myopia and amblyopia. We report a case of this rare condition with unilateral extensive MRNF, axial myopia, amblyopia and strabismus in a Nigerian girl.     

Screening Amblyopia for Year 1 Students with Uncorrected Vision and Stereopsis Test in Central China

Background: Screening for amblyopia at earliest is important for early treatment and better prognosis. This study aimed at evaluating the validity of uncorrected distant and near visual acuity and stereoacuity for screening amblyopia in year 1 students in central China. Methods: By stratified cluster sampling, 3112 year 1 students from 11 Anyang primary schools were selected for the study. All the participants underwent uncorrected distant and near visual acuity, stereopsis test, cycloplegic refraction, best corrected visual acuity (BCVA), cover test and ocular movement examination. Visual acuity (VA) was measured with a logarithm of the minimum angle of resolution (logMAR) chart. Stereoacuity was measured with the Lang II stereo card and TNO test. Amblyopia was defined as the BCVA less than or equal to 0.1 logMAR units of any eye in the absence of significant pathological abnormalities. The sensitivity, specificity, positive predictive value and negative predictive value of uncorrected visual acuity and stereoacuity for amblyopia were analyzed. Results: Out of the 3112 eligible students, 2893 (92.96%) students completed the examinations. The average age of the students was 7.10±0.41 （mean ± standard deviation, SD）years. Screened by distant visual acuity with low cutoff (logMAR0.1), high cutoff (logMAR0.0) and near visual acuity (logMAR0.0), 31.64, 73.18 and 50.23% students were abnormal. Screened by stereopsis test, only 4.69% students were abnormal. By a senior pediatric ophthalmologist, 61 students were diagnosed amblyopia. The sensitivities of distant visual acuity with low/high cutoff and near visual acuity were 92.31/100.00 and 80.77%, whereas that of stereoacuity by TNO test was 15.38%. Simultaneous testing of either two of the three tests improved the sensitivity. Conclusions: Distant visual acuity test of high cutoff alone display a high sensitivity but a low specificity. Simultaneous testing of distant visual acuity of low cutoff and stereoacuity is a better choice to balance between sensitivity and specificity.     

Is microtropia a reliable indicator of the presence of amblyopia in anisometropic patients?

Aim: A study was carried out to determine if the presence of microtropia with identity is a reliable indicator for the presence of amblyopia, and likely need for occlusion, following optical treatment in “straight-eyed” anisometropic children. Method: A retrospective case note review was carried out of all children referred from Orthoptic school vision screening during a 10-year period. Children who had unequal visual acuity, no manifest strabismus and who were prescribed spectacles to correct anisometropia (inter-ocular difference one dioptre or more in any meridian) were included in the study. The presence or absence of microtropia with identity, determined using the 4-dioptre prism test, was recorded and children were grouped according to visual outcome as follows: Group 1: equal visual acuity after a maximum optical treatment period of 2 months; Group 2: equal visual acuity after a maximum optical treatment period of 6 months; Group 3: unequal visual acuity after a maximum optical treatment period of 6 months – no occlusion therapy undertaken; and Group 4: unequal visual acuity after a maximum optical treatment period of 6 months – occlusion therapy undertaken.

Results: Case notes were available for a total of 532 children. Out of 532, 324 children achieved equal visual acuity with optical treatment alone; none had microtropia. Thirty children with microtropia achieved LogMAR acuity of 0.200 or better in the affected eye after optical treatment and did not undergo occlusion therapy; 178 children required occlusion therapy to achieve a maximum LogMAR acuity of 0.300 or better, and all had microtropia.

Conclusion: In this study of 532 four–five year olds, amblyopia did not exist in “straight-eyed” anisometropic children who did not have microtropia with identity. This study suggests that the presence of microtropia with identity is a reliable indicator of the presence of amblyopia, and possible need for occlusion therapy, following optical treatment in “straight-eyed” anisometropic children.     

The effects of experimentally induced graded monocular and binocular astigmatism on near stereoacuity

Purpose

To determine the effects of experimentally induced graded monocular and binocular astigmatism on near Stereoacuity in healthy adults.

岳阳市学龄前弱视儿童头发微量元素的检测及其临床意义

目的探讨微量元素与儿童弱视之间的关系,为临床合理用药治疗儿童弱视提供依据。方法对分布在岳阳市城乡的232名弱视儿童及对照组儿童采用电感耦合等离子体质谱法（ICP-MS）进行头发微量元素测定,应用SPSS13.0软件进行统计分析。结果弱视儿童发Zn、Se、Cu元素含量明显低于正常儿童,但弱视儿童发Zn、Se、Cu含量男女间分别比较差异无统计学意义（P〉0.05）;城区弱视儿童发Zn元素含量明显高于乡镇弱视儿童,而城乡弱视儿童发Se、Cu元素含量两组间分别比较差异无统计学意义（P〉0.05）。结论弱视儿童头发微量元素异常,对弱视成因有一定影响,建议重视并及时纠正儿童异常的微量元素。     

YZH综合弱视治疗机在治疗儿童弱视中的效果及护理

目的探讨YZH综合弱视治疗机在治疗儿童弱视中的有效性和安全性。方法将40例首诊确诊为弱视的患儿按弱视程度随机分为两组,各20例。对照组选择一般疗法治疗,观察组选择一般疗法同时用YZH综合弱视治疗机进行弱视治疗。结果两组均取得了一定疗效,对照组33只眼总有效率66．67％,无效率为33．33％;观察组38只眼总有效率97．37％,无效率为2．63％。两组疗效比较,差异有统计学意义（x^2=11．8536,P〈0．05）。结论YZH综合弱视治疗机能安全、有效地治疗儿童弱视,完善治疗前后护理,在治疗过程中取得患儿的积极合作,家长的关心,增加治疗的依从性,能提高治疗、护理效果,促进患儿早日康复。     

学龄前儿童视觉发育状况调查研究

目的 了解学龄前儿童视觉发育状况及斜弱视患病率.方法 对4610名城乡3～6岁学龄前儿童进行随机抽样调查,项目包括视力、屈光状态、眼位、斜视弱视等.用x2检验城乡及不同年龄视力分布差异.结果 3岁、4岁、5岁和6岁组儿童视力1.0以上检出率分别为28.4％、39.3％、46.2％、76.5％,各年龄组视力主要分布3岁(0.63±0.19)、4岁(0 69±0.16)、5岁(0.71±0.22)、6岁(0.79±0.29),乡镇较城市儿童视力好.屈光状态以远视为主;显性斜视检出率为2.21％,外斜视多见于内斜视;隐性斜视检出率为33.52％,主要是外隐斜;弱视患病率以现行诊断标准为6岁组2.93％,5岁组4.81％,4岁组16.21％,3岁组33.33％.结论 学龄前儿童视力随年龄增长而上升;国内弱视诊断中视力标准偏高,应尽快制定各年龄组弱视诊断视力标准.屈光不正、斜视和弱视是影响学龄前儿童正常视功能的主要因素,依然是儿童时期防盲治盲的重点.