Accommodative convergence in hypermetropia

We compared the clinical characteristics of esotropic, hypermetropic children whose strabismus was fully corrected with spectacles (refractive accommodative esotropia) with those who remained orthotropic (that is, had no manifest strabismus on the cover test) in the presence of uncorrected hypermetropia. In addition to a standard ophthalmologic and orthoptic examination, we determined the stimulus accommodative convergence/accommodation (AC/A) ratio by using the gradient method over a range of 6 diopters, the near point of accommodation, and random dot stereopsis. Hypermetropic patients without esotropia or significant esophoria were found to have a low AC/A ratio in contrast to those patients with refractive accommodative esotropia. This finding explains why esodeviations may be absent in some hypermetropic patients with uncorrected vision. We found a high prevalence of abnormally low near points of accommodation and defective or absent stereopsis in both groups of patients.     

Risk factors for the development of accommodative esotropia following treatment for infantile esotropia.

PURPOSE: One aim of the study was to determine whether accommodative esotropia after surgical alignment in infantile esotropia occurs because a pre-existing accommodative component is unmasked at the time of surgery or whether it occurs as a sequela of infantile esotropia. A second aim of the present study was to examine risk factors for accommodative esotropia after surgery for infantile esotropia. METHODS: A total of 80 consecutive patients who were enrolled in a prospective study of infantile esotropia had been followed for more than 4 years and had achieved orthoposition were included. Twelve potential risk factors were examined: age at onset, initial esodeviation, initial refractive error, age at alignment, delay in alignment, presurgical glasses, amblyopia, additional surgical procedures, unstable alignment, increase in hypermetropia, peripheral fusion, and stereopsis. Mantel-Haenszel odds ratios were computed for each factor and were corrected to relative risks. RESULTS: Overall, 48 of 80 children (60%) developed accommodative esotropia at a mean age of 33 months. Increasing hypermetropia, delay in alignment, and poor stereopsis posed significant risks for accommodative esotropia. The remaining 9 factors were not associated with increased risk for accommodative esotropia. CONCLUSIONS: Accommodative esotropia is unlikely to be a pre-existing condition in most cases because the mean age of onset was 23 months postoperative and the prevalence of preoperative hypermetropia greater than +3.00 D was low. Both delay in alignment and stereopsis risk factors may reflect compromised binocular sensory status that allows accommodative esotropia to occur at low to moderate levels of hypermetropia. Identification of children treated for infantile esotropia who are at risk for accommodative esotropia may allow for prevention or early treatment.     

Risk factors for abnormal binocular vision after successful alignment of accommodative esotropia.

PURPOSE: The purpose of this study was to identify clinical factors associated with abnormal binocular vision outcomes among children with accommodative esotropia (ET) whose eyes were successfully realigned with spectacles only or with spectacles and surgery. METHODS: The participants were 69 children with accommodative ET who were followed up prospectively from the time of diagnosis. Clinical factors examined in this study included high accommodative convergence-to-accommodation (AC/A) relationship, high hyperopia, anisometropia, age of onset, and duration of eye misalignment. Binocular vision was assessed using measures of stereopsis, fusional vergence, sensory foveal fusion, and motion visual-evoked potential (mVEP). RESULTS: Children with a high AC/A relationship are 2.2 times more likely to have an absence of fusional vergence than are children with a normal AC/A relationship. Children having a duration of constant eye misalignment >/= 4 months before being successfully treated are 4.6 times more likely to have abnormal stereopsis, 33 times more likely to have no stereopsis, 37 times more likely to have an absence of fusional vergence, 31 times more likely to have an absence of sensory foveal fusion, and 17 times more likely to have an asymmetric mVEP response than children with a duration of constant ET diagnosed at 0 to 3 months. CONCLUSIONS: Following successful eye alignment, as many as 75% of patients with accommodative ET had anomalous binocular vision. A high AC/A relationship poses a significant risk for abnormal fusional vergence only. A constant eye misalignment lasting >/= 4 months poses a significant risk for anomalous binocular vision on all measures studied.     

A family of squints: the differing effects of hypermetropia on four siblings

Four siblings in a family of five were found to be affected with hypermetropia in differing degrees and with differing effects. These were unilateral hypermetropia, producing amblyopia; hypermetropia inducing an accommodative esotropia with minimal amblyopia and fully controlled with glasses; hypermetropia producing an accommodative esotropia with a high AC/A ratio, fully controlled with bifocals; and hypermetropia producing esotropia which was only partially corrected with glasses, therefore partially accommodative, with a residual squint which required surgery. This family of four nicely demonstrates all the permutations and combinations possible in accommodative-type esotropia and the pitfalls therein.     

A FAMILY OF SQUINTS: THE DIFFERING EFFECTS OF HYPERMETROPIA ON FOUR SIBLINGS

Four siblings in a famil of five were found to be affected with hypermetropia in differing degrees and with differing effects. dese were (i) unilateral hypermetropia, producing amblyopia; (ii) hypermetropia inducing an accommodative esotropia with minimal amblyopia and fully controlled with glasses; (iii) hypermetropia producing an accommodative esotropia with a high AC/A ratio, fully controlled with bifocals; and (iv) hypermetropia producing esotropia which was only partially corrected with glasses, therefore partially accommodative, with a residual squint which required surgery.
This family of four nicely demonstrates all the permutations and combinations possible in accommodative-type esotropia and the piifalls therein.     

Risk factors for accommodative esotropia among hypermetropic children

PURPOSE: Identification of risk factors for accommodative esotropia may help to determine which children with hyperopia may benefit from early spectacle correction or preventive therapy. METHODS: Participants in the family history study were 95 consecutive patients, aged 18 to 60 months, with accommodative esotropia. Participants in the binocular sensory function study were a subgroup of 41 children enrolled in the family history study within 1 month of onset, while the esodeviation was still intermittent. Participants in the hypermetropia study were 345 consecutive patients, ages 12 months to 8 years, with refractive error of +2.00 D or greater and no esodeviation before age 12 months. RESULTS: In the family history study, 23% of children with accommodative esotropia had an affected first-degree relative, and 91% had at least one affected relative. In the binocular sensory function study, random-dot stereoacuity was abnormal in 41% of children, whereas an abnormal motion VEP, Worth 4-dot, or positive 4-PD base-out prism responses were present in 4% or less of the children. In the hypermetropia study, patients with a mean spherical equivalent of < +3.00 D and significant anisometropia had a 7.8-fold increased risk for accommodative esotropia over nonanisometropic patients. CONCLUSIONS: A positive family history, subnormal random-dot stereopsis, and hypermetropic anisometropia each pose a significant risk for the development of accommodative esotropia. Assessment of these risk factors in conjunction with refractive screening should help to identify those children who are most likely to benefit from early spectacle correction or preventive treatment.     

内直肌后固定术治疗集合过强型内斜视的临床观察

目的 观察内直肌后固定术治疗集合过强型内斜视的临床效果.方法 回顾性分析2006年2月到2007年5月行内直肌后固定术治疗的17例集合过强型内斜视的临床资料.结果 17例患者中,术前平均看远内斜度为8.8△、平均看近内斜度为24.2△、平均AC/A比率为10.7.术前有12例无舣眼单视功能,仅5例具有远立体视.术后平均随访12.6月(9～15月),平均看远内斜度为2.8△、平均看近内斜度为3.9△、平均AC/A比率为5.9,其中看近内斜度较术前平均下降20.2△,AC/A比率均达到正常.术后有13例具有双眼单视功能.结论 内直肌后固定术可以减少看近的内斜视度数,降低AC/A比率,是一种治疗集合过强型内斜视的安全有效的方法.     

内直肌后固定术治疗集合过强型内斜视的临床观察

目的 观察内直肌后固定术治疗集合过强型内斜视的临床效果.方法 回顾性分析2006年2月到2007年5月行内直肌后固定术治疗的17例集合过强型内斜视的临床资料.结果 17例患者中,术前平均看远内斜度为8.8△、平均看近内斜度为24.2△、平均AC/A比率为10.7.术前有12例无舣眼单视功能,仅5例具有远立体视.术后平均随访12.6月(9～15月),平均看远内斜度为2.8△、平均看近内斜度为3.9△、平均AC/A比率为5.9,其中看近内斜度较术前平均下降20.2△,AC/A比率均达到正常.术后有13例具有双眼单视功能.结论 内直肌后固定术可以减少看近的内斜视度数,降低AC/A比率,是一种治疗集合过强型内斜视的安全有效的方法.     

应用下加压贴球镜治疗小角度高AC／A调节性内斜视

目的探讨小角度高AC／A调节性内斜视的治疗方法。方法给14例小角度高AC／A调节性内斜视儿童长期佩戴下加压贴球镜的双焦点眼镜,并观察眼位变化及近立体视功能。结果戴镜后所有患者视近眼位正位,AC／A值2—4;14例Titmus检查获400″-40″立体视锐度,11例随机点图片检查获800″-60″立体视锐度。结论8岁前儿童长期佩戴压贴膜球镜制做的双焦点眼镜,可以替代双焦点眼镜治疗小角度高AC／A调节性内斜视。     

Retinal correspondence in typical accommodative esotropia

Typical (refractive) accommodative esotropia is a form of acquired esotropia caused primarily by hypermetropia; correction of the hypermetropic refractive error with convex lenses generally leads to rehabilitation. A significant number of cases clinically diagnosed as typical accommodative esotropia do not, however, respond satisfactorily to this form of treatment, suggesting the presence of nonrefractive etiological factors. Fifty cases diagnosed by conventional methods as typical accommodative esotropia were examined with the fundus haploscope; abnormal or subnormal retinal correspondence was discovered in nearly 50% of the total. Congenital elements are thought to play a contributory role in these cases.Dedicated to Dr. G.K. von Noorden on the occasion of his 60th birthday     

The efficacy of SimulVue and Unilens RGP aspheric bifocal contact lenses in the treatment of esotropia associated with a high accommodative convergence/accommodation ratio.

PURPOSE: This was a prospective study assessing the efficacy of the SimulVue bifocal contact lens and the Unilens RGP aspheric multifocal contact lens (Unilens, Largo, Fla.) in the treatment of high accommodative convergence/accommodation (AC/A) esotropia in an adolescent and postadolescent population. METHODS: Those patients meeting the inclusion criteria were fit with contact lenses with use of full cycloplegic refraction and later retested by an examiner masked to the previous binocular status. Particular attention was given to the sensory status and the motor fusion of each patient in their bifocal spectacles and then in their bifocal contact lenses. All patients were followed up for at least 6 months after the contact lenses were fitted. RESULTS: Five of the six patients demonstrated larger angles of esophoria or tropia at near with the contact lenses than with bifocal spectacles. The only patient who maintained excellent stereopsis in bifocal contact lenses was the one who normalized her AC/A ratio during this study and no longer required a bifocal in her spectacle correction for fusion. The two patients who initially had no stereopsis but good alignment in spectacle correction had a large esotropia at near fixation with bifocal contact lenses. CONCLUSIONS: The SimulVue and Unilens RGP aspheric bifocal contact lenses did not adequately treat adolescent patients who had esotropia associated with a high AC/A ratio.     

阿托品眼局部滴用对儿童共同性内斜视影响的初步研究

目的探讨眼局部应用1％阿托品对儿童共同性内斜视斜视角度、调节性集合和双眼视功能的影响。设计前瞻性临床研究。研究对象共同性内斜视患者35例（3—15岁）。方法1％阿托品眼用凝胶进行散瞳验光前、后分别进行斜视角度、调节性集合，调节（AC／A）、双眼视觉测定，并根据验光结果分为≤＋3D、〉＋3D并≤＋6D和〉＋6D三个不同屈光度组，对其散瞳前后的各项指标变化进行分析。主要指标斜视角度（三棱镜度）、AC／A、同时知觉、融合功能、远立体视觉、近立体视觉。结果3组患者中斜视角度≤50^Δ和≥55Δ的患者分布无显著性差异（χ2=0．52，P=0．77）；14例≤3D患者中散瞳后的斜视角度无变化者11例（78．57％），斜视角度减小者仅2例（14．29％），而11例〉3D并≤6D患者和10例〉6D患者中散瞳后斜视角度减小者均为5例（分别为45．46％和50．00％）。三组患者中，散瞳前AC／A的分布无显著性差异（χ2=4．87，P=0．30）。散瞳后各组AC／A均有减小的趋势，变化无显著性差异（χ2=1．89，P=0．75）。5例具有不同程度双眼视觉者，其斜视角度均≤20Δ。结论在儿童共同性内斜视中，低度远视患者散瞳前后斜视角度无明显变化，部分中、高度远视患者散瞳后斜视角度有减小趋势。     

Effect of hyperopic laser in situ keratomileusis on ocular alignment and stereopsis in patients with accommodative esotropia

OBJECTIVE: To evaluate the effect of laser in situ keratomileusis (LASIK) on ocular alignment and stereopsis in patients with accommodative esotropia. DESIGN: Retrospective, non-comparative, interventional case series. PARTICIPANTS: Since 1998, 27 patients (mean age, 33.3 years; range, 10-52 years) with comitant esophoria or esotropia and hyperopia meeting eligibility requirements underwent bilateral LASIK for correction of refractive error. INTERVENTION: Bilateral hyperopic LASIK was performed using the Technolas Keracor 217 excimer laser (Bausch & Lomb) in 22 patients and using the Nidek 5000 excimer laser in 5 patients. MAIN OUTCOME MEASURES: Visual acuity (best-corrected and uncorrected), refractive error, ocular alignment, and stereopsis were recorded before and after LASIK. Log transformation of each visual acuity was done before data analysis. RESULTS: Using paired t tests, the mean uncorrected esotropia was significantly reduced from 9.0 prism diopters (PD) (range, 0 [esophoria only] to 20 PD; standard deviation [SD], 7.39) before surgery to 3.3 PD (range, 0-15 PD; SD, 6.20) after surgery (P < 0.0001). Most patients (14 patients, 58%) had a reduction in esodeviation after LASIK, but 10 patients (42%) had no response to surgery, and these patients could not be predicted on the basis of preoperative sensorimotor testing. No patient had a worsening sensorimotor status after LASIK. Nine patients subsequently underwent conventional eye muscle surgery. CONCLUSIONS: Hyperopic LASIK was effective in reducing the mean uncorrected esotropia in this group of patients. However, accurately determining those patients most likely to benefit from the procedure was difficult.     

Bilateral phakic hypermetropic epikeratoplasty for accommodative esotropia

Optical correction of high hypermetropia with glasses is the primary treatment for accommodative esotropia. These glasses are often poorly accepted by adolescents and young adults for they are cosmetically undesirable, heavy, and esotropia occurs with their removal. We report an 11 1/2-year-old, physically mature female with high hypermetropia and accommodative esotropia corrected to orthophoria with glasses who was unable to be weaned from her glasses. She became intolerant to glasses wear, refused contact lenses, and was treated successfully with bilateral phakic hypermetropic epikeratoplasty. Two years postepikeratoplasty her visual acuity is 20/40 and 20/20 uncorrected and the vision in the amblyopic right eye has remained at its maximum preoperative level. She is orthophoric at distance and has a 2 prism diopter monofixational esophoria at near without glasses. Epikeratoplasty is an option in the treatment of accommodative esotropia for patients who are past the amblyopia forming age, have a stable angle of strabismus, and who require their full hypermetropic optical correction to maintain orthophoria.     

Motion VEPs, stereopsis, and bifoveal fusion in children with strabismus

PURPOSE: The link between nasal-temporal motion asymmetries and anomalous binocular sensory function in infantile esotropia (ET) has led to the idea that visual evoked potential responses to horizontal motion (mVE) is an alternative measure of sensory binocularity to stereopsis. A second hypothesis is that the mVEP response is a marker for bifoveal fusion. The purpose of this study was to directly evaluate these two hypotheses by examining the correspondence between the mVEP response and both stereoacuity and bifoveal fusion in a cohort of strabismic patients with variable binocular sensory function. METHODS: Motion VEPs, random dot stereopsis, and bifoveal fusion were measured in 94 children: 20 with infantile ET, 16 with infantile accommodative ET, 22 with late-onset accommodative ET, 10 with intermittent infantile strabismus, and 26 normal control participants. RESULTS: Patients with infantile ET and infantile accommodative ET had high concordance between mVEP responses and stereoacuity and mVEP responses and bifoveal fusion. Asymmetric mVEP responses were highly concordant with both no measurable stereopsis and an absence of fusional vergence. Patients with late-onset accommodative ET and intermittent infantile strabismus revealed discordance between the mVEP response and stereoacuity and high concordance between the mVEP response and bifoveal fusion. Asymmetric mVEP responses were highly concordant with the absence of bifoveal fusion and the minimum-size prism to elicit fusional vergence. CONCLUSIONS: The qualitative and quantitative relationship between the mVEP response and fusional vergence suggests that the mVEP response is an objective measure of bifoveal fusion. The availability of such a test will facilitate studies of normal development of bifoveal fusion and development of monofixation syndrome in strabismus.     

间歇性外斜视儿童的融合功能研究

目的探讨间歇性外斜视儿童融合功能的状况。设计回顾性病例系列。研究对象间歇性外斜视儿童48例。方法采用同视机检测48例间歇性外斜视儿童的三级视功能,采用颜少明随机点《立体视觉检查图》检查视近立体视锐度,并以正常相同年龄儿童20例做对照。主要指标同时视、融合范围及立体视锐度。结果48例患者中,8例无重合点,余40例中34例患者的重合点均落在外融合范围内。11例患者无Ⅱ级融合功能,余37例患者的内、外融合范围分别是（12．74±5．57）度和（4．97±2．11）度;正常对照组的内、外融合范围分别为（24．05±6．67）度和（3．52±0．96）度,两组比较差异有统计学意义（P均〈0．05）。以同视机检测,23例（47．92％）患者无立体视,而以颜氏随机点立体视觉图检测,仅2例（4．17％）近立体视丧失。结论间歇性外斜视儿童的融合功能异常,外融合范围扩大、内融合范围缩小;远立体视觉的丧失早于近立体视觉的丧失。     

Accommodative Esotropia Long Range Follow-up

Thirty-nine adult patients treated for typical (refractive) accommodative esotropia in childhood continue to have problems because they have not outgrown their hypermetropia, and the majority have not developed stable binocular vision. Their hypermetropia became maximal (median 5.7 diopters) by age 6, decreased in adolescence, and then stabilized (median 4 diopters). Thirty-eight of the 39 adults wear correcting lenses full-time. Nearly all depend on relaxed accommodation to maintain alignment when they remove their glasses. Ten patients, all of whom received treatment before a constant esotropia developed are essentially orthophoric with glasses and have normal binocular vision. The remainder have small-angle deviations with glasses, 14 with varying degrees of amblyopia and peripheral fusion and 15 with anomalous correspondence and suppression. As adults, only one patient with normal binocular function has required surgery whereas 13 of the patients lacking normal fusion have had surgery for increasing esotropia, postoperative exotropia, or consecutive exotropia.     

周期性内斜视的屈光状态与临床治疗

目的 探讨周期性内斜视的屈光状态与治疗方法。方法 对２４例周期性内斜视者用１％阿托品液散瞳验光检验屈光度。斜视日与正位日用三棱镜测量斜视度,用同视机检验双眼立体视觉。手术量按斜视日最大斜视角有设计。结果 轻度、中度远视２３例。斜视日均有复视。正位日均有双眼立体视觉,斜视矫正术后２３例在斜视日与非斜视日眼位均矫正有正常的立体视觉。结果 为获得正常的双眼立体视功能,应在周期性期间及早手术。手术量控斜视     

Surgical outcomes for esotropia in children with high accommodative convergence/accommodation ratio

Purpose:To assess if high accommodative convergence/accommodation (AC/A) ratio impacts surgical outcomes in children with esotropia (ET), and evaluate the appropriate target angle in surgical dosing in the presence of high AC/A ratio.Methods:A retrospective chart review identified patients who underwent primary bilateral medial rectus (BMR) recessions for ET. Patients were excluded if follow-up was ≤2 months. Basic demographic information, visual acuity, stereopsis, alignment, and target angle for surgery were collected. High AC/A was defined as ≥10 prism diopter (Δ) deviation at near compared to distance. Outcome parameters were near and distance deviations ≤10Δ within orthophoria, and/or stereopsis postoperatively. Yates’ continuity correction, unpaired t-test, regression analysis, and one-way ANOVA were used.Results:We identified 103 patients, 23 with high AC/A and 80 with normal AC/A, preoperatively. Mean age was 4.0 ± 2.5 years. Surgical success measured by postoperative alignment was 48% and 45% in the high AC/A and normal AC/A groups, respectively (P = 1.0). There was a statistically significant difference in preoperative near deviation between high AC/A and normal AC/A groups (P = 0.0015); however, there was no significant difference in preoperative distance deviation (P = 0.061). In addition, there was not a significant difference in preoperative or postoperative stereopsis between high AC/A and normal AC/A groups (P = 0.88 and P = 0.44, respectively). There was a significant difference in the normal AC/A and high AC/A groups when target angle was directed toward preoperative near deviation as determined by one-way ANOVA (F = 170.88, P < 0.0001 and F = 14.61, P = 0.0010, respectively).Conclusion:In the setting of ET treated with BMR recession, the presence of high AC/A does not affect surgical success as measured by alignment and stereopsis. In addition, when high AC/A is present, surgical dosing with a target angle toward near deviation was found to yield the best surgical outcomes in our patient population.