重视斜视术后双眼视功能的重建

双眼视是双眼输入的视觉信息进行加工整理最终形成三维立体视觉的过程，属于大脑皮层的高级认知活动。斜视因为眼位的偏斜产生复视和混淆视，进而引起视觉抑制、异常视网膜对应、注视异常、三级视功能受损等一系列双眼视异常，严重影响了双眼视觉形成和发育。手术治疗为斜视的主要的治疗方法，但斜视矫正术后大部分患者无法获得正常的双眼视功能，而斜视的治疗应以重建双眼视功能为目标。斜视治疗不仅要重视眼位的恢复，更要重视双眼视功能的重建。重建双眼视功能在减少斜视的复发率，提高斜视的治疗效果方面具有积极的作用，并大大提高斜视患者术后的生活质量。所以双眼视功能重建应在斜视治疗中占有更重要的地位。斜视的早期手术治疗是建立双眼视觉的先决条件，同时应重视术后正确的屈光矫正和弱视的治疗，正确选用训练手段，个性化制定训练方案，才能促进双眼视功能的重建。     

Restoration of binocular single vision after long-term fusion disruption.

BACKGROUND: One of the most difficult situations faced by orthoptists and pediatric ophthalmologists is attempting to restore binocular single vision to a patient who has experienced a long-term disruption of fusion. Initial poor results with standard treatment modalities, including prisms and strabismus surgery, may lead to a diagnosis of intractable diplopia. METHODS: We examined, treated, and followed up 5 patients with strabismus after an extended period of monocular vision loss. All patients were diplopic after the restoration of visual acuity in the affected eye. RESULTS: All 5 patients experienced a period of uncomfortable intermittent fusion with the initial prismatic correction. After many months of close follow-up with prism and orthoptic therapy, comfortable fusion was restored for 3 patients. Convergence amplitudes improved with the orthoptic exercises, and we were eventually able to eliminate most or all of the horizontal prism in the 3 patients who regained binocular single vision; however vertical fusion was less responsive and most often required permanent prismatic correction. CONCLUSIONS: A combination of prism therapy, orthoptic treatment, and follow-up during a period of many months to years can restore fusion in some patients who have experienced a long-term disruption of fusion.     

Binocular sensory outcomes in accommodative ET

PURPOSE: To review what is known about the normal maturational sequence for fusion and stereopsis and the binocular sensory deficits associated with accommodative esotropia (ET) and to explore the clues that accommodative ET provides about critical periods for binocular sensory function. METHODS: Studies of binocular sensory function during infancy and early childhood are presented. RESULTS: Most of the maturation of binocular sensory function occurs during the first year of life, yet a later abnormal visual experience-such as the onset of accommodative ET--can profoundly and permanently disrupt fusion and stereopsis. CONCLUSIONS: Some binocular sensory deficits may exist before the onset of accommodative ET, but others may result directly from abnormal binocular experience. The functional organization of the maturing visual system appears to be maximally sensitive to disruption by abnormal visual experience during the first months of life, but susceptibility continues until at least 4 years of age.     

Predictive factors underlying the restoration of macular binocular vision in adults with acquired strabismus.

PURPOSE: To investigate whether macular binocular vision can be permanently lost following acquired strabismus and to identify predictive factors underlying its restoration. SUBJECTS AND METHODS: Twenty-three patients with strabismus acquired after binocular vision maturation were enrolled. Factors studied included duration of eye misalignment, age at treatment, pre-surgical strabismus type, pre-surgical diplopia, and pre-surgical capacity for binocularity. The restoration of macular binocular vision was evaluated between 1 and 3 years following successful eye re-alignment and was defined as 60 seconds of arc stereopsis or better on the Titmus circles and/or the Preschool Randot Stereoacuity test. RESULTS: Sixteen of 23 (70%) or 7/23 (30%) of patients achieved macular binocular vision following successful surgical eye realignment using the Titmus circles versus the Preschool Randot Stereoacuity test. Patients with < or =12 months constant eye misalignment were more likely to achieve macular binocular vision following treatment than patients with >12 months constant eye misalignment. CONCLUSIONS: Macular binocular vision continues to be susceptible to permanent loss in adult patients. Factors that are predictive of the restoration of macular binocular vision include duration of constant eye misalignment and the pre-surgical capacity for binocularity.     

斜视对双眼视觉功能的影响及术后康复

人类立体视功能的产生有诸多必要条件,双眼平行的视觉方向是其中之一。斜视后双眼的视觉方向不再平行,从而导致双眼视觉功能破坏;同时双眼视觉功能的丧失也意味着中枢对眼位的控制能力变差,进而促进斜视的发展。斜视的主要治疗方法是手术,术后患者可以达到双眼正位,但很多患者的双眼视觉功能并未恢复,一些患者还会由于双眼视觉功能的异常导致短期内斜视复发。因此,斜视的治疗不仅是手术达到双眼正位,术后双眼视觉的康复也同样重要。术后康复训练方法主要包括同视机双眼视觉康复训练、融合能力训练、电脑软件训练、视感知觉训练法等。人类大脑终身具有可塑性,如在术后双眼正位的情况下及时加以适当训练,帮助患者更好地恢复双眼视觉功能,加强大脑对双眼眼位的控制力,更好地保持术后双眼正位。（国际眼科纵览, 2018,  42:   179-183）     

Stereoacuity and foveal fusion in adults with long-standing surgical monovision

PURPOSE: Although binocular vision deficits occur in children who have a constant esotropia onset following significant maturation of stereopsis, it is uncertain whether adults are susceptible to changes to binocular vision. We examined binocular vision in adults with longstanding surgical monovision (> or =6 month's duration) to determine whether the binocular visual system remains susceptible to change. METHODS: Participants included 32 adults with longstanding monovision through laser-assisted in situ keratectomy or photorefractive keratectomy and 20 age-matched control subjects. After full binocular correction, binocular function was measured by using the Randot Stereoacuity Test, the Randot Preschool Stereoacuity Test, and the Worth 4-dot test at near and distance. Monovision patients were grouped as having low anisometropia (<1.5 spherical D) or moderate anisometropia (> or =1.5 spherical D). RESULTS: Non-parametric analysis of variance revealed a significant difference between group median stereoacuity (H = 16.062; P <.001). Pairwise multiple comparisons indicated both groups with monovision had significantly worse stereoacuity compared with control subjects (P <.05). Median stereoacuity values were 100 seconds of arc for patients with low anisometropia, 150 seconds of arc for patients with moderate anisometropia, and 40 seconds of arc for control subjects. A larger proportion of patients with moderate anisometropia failed the Worth-4 dot test at distance than control subjects (z = 2.619; P =.009). CONCLUSIONS: Reduced stereoacuity and an absence of foveal fusion in adults with longstanding surgical monovision suggest continued susceptibility of the binocular visual system to anomalous binocular experience.     

Fresnel prism treatment of sensory exotropia with restoration of sensory and motor fusion

Anterior segment surgeons may treat patients with long-standing media opacities or uncorrected aphakia who have developed sensory strabismus. These patients are at risk for diplopia after surgery to clear the visual axis and restore emmetropia. This report describes 2 patients who regained comfortable single binocular vision without strabismus surgery. Sensory fusion was restored with Fresnel prisms, which were weaned and ultimately discarded as the patients' motor fusion was re-engaged after decades of disuse. Surgeons who restore vision in an eye with manifest sensory strabismus should be aware of this noninvasive, well-tolerated treatment option. Collaboration with an orthoptist or strabismologist may be helpful.     

Binocular diplopia following vision restoration in patients with keratoconus and sensory strabismus

PURPOSE: To report the phenomenon of newly-noted binocular diplopia following vision improvement in patients with sensory strabismus secondary to keratoconus, and to document the effect of strabismus surgery on this diplopia. METHODS: Retrospective institutional case series [1982--2005] of records coded with keratoconus and strabismus. Keratoconus patients with visual acuity that could not be improved, childhood strabismus, known reason for acquired strabismus (other than decreased vision from kerataconus), decreased vision from other ocular disease, monocular diplopia, failure of strabismus surgery, and/or less than six months follow-up after strabismus surgery were excluded. RESULTS: Although 103 medical records were identified, only seven met the strict inclusion criteria. All seven patients presented with gradual reduction in vision (not due to their strabismus), and none initially complained of diplopia. After intervention to improve visual acuity, six complained of constant binocular diplopia. This diplopia resolved after successful strabismus surgery. Postoperative Worth four-dot testing demonstrated suppression. CONCLUSIONS: Binocular diplopia, noted after intervention to improve visual acuity in our patients with strabismus secondary to long-standing uncorrected keratoconus, resolved after successful surgical alignment. Our patients may have developed suppression from uncorrected keratoconus before their sensory strabismus occurred.     

Factors influencing stereoacuity outcomes in adults with acquired strabismus

PURPOSE: Functional improvements of binocular vision after strabismus surgery in adults are common but not well understood. In a prospective study, factors associated with stereoacuity outcome in patients with strabismus acquired following binocular vision maturation were investigated. DESIGN: Prospective data collection. METHODS: Twenty-three patients aged 14 to 85 years with acquired strabismus were enrolled. Random dot stereoacuity was quantified using a battery of tests including the Randot Preschool Stereoacuity test, the Randot (version 2) shapes test, and the Randot Butterfly test. RESULTS: Ninety-six percent of patients achieved measurable stereoacuity following successful eye realignment. Better median stereoacuity is achieved in patients with the following characteristics: < or =12 months of constant strabismus (60 vs 400 seconds of arc with >12 months' strabismus, P < .001); a presurgical capacity for fine to moderate stereopsis (60 vs 400 seconds of arc with coarse or no measurable stereopsis, P < .005); a presurgical capacity for macular fusion (60 vs 400 seconds of arc with no measurable macular fusion capacity, P < .001); and postsurgical orthotropia (100 seconds of arc) or intermittent orthotropia (100 seconds of arc vs 2000 seconds of arc with 5 to 8 prism diopters (PD) of postsurgical residual strabismus, P < .05). CONCLUSION: Surgical correction of acquired strabismus is associated with recovery of stereopsis. Factors associated with stereoacuity outcomes include duration of strabismus and presurgical binocular vision capacity. A postsurgical correction of orthotropia or intermittent orthotropia supports better stereoacuity than a larger residual angle of strabismus subtending up to 8 PD of deviation.     

成人外斜视术后双眼视觉重建及其影响因素

目的探讨成人外斜视术后双眼视觉重建及其影响因素。方法回顾性病例研究。收集发病年龄相对明确的术前无双眼视功能的成人外斜视患者54例,按发病年龄9岁之前或之后分为BVM（before visual maturity,<9岁者）组及AVM（after visual maturity,≥9岁者）组,分别于术前及术后6周用同视机测远双眼视觉,用颜氏《数字化立体视图》测近立体视觉。采用χ²检验分析比较2组患者术后双眼视功能的变化;采用logistic回归分析发病年龄、手术年龄、术前斜视度数、外斜视类型对术后立体视的影响。结果术后远双眼视觉重建率：I级：AVM组77%,BVM组33%（χ²=10.240,P<0.01）;Ⅱ级：AVM组77%,BVM组33%（χ²=10.240,P<0.01）;III级：AVM组47%,BVM组17%（χ²=5.400,P<0.05）。近立体视重建率：AVM组73%,BVM组29%（χ²=10.461,P<0.01）。Logistic多因素回归分析显示,发病年龄及手术年龄是影响术后远（OR=6.046,P<0.05;OR=0.140,P<0.01;）、近立体视（OR=10.825,P<0.05;OR=0.189,P<0.05）重建的重要因素,而术前斜视度数及外斜视类型对术后远、近立体视的重建无显著影响。结论成人外斜视术后也可获得一定程度的双眼视功能,甚至是立体视功能。发病年龄及手术年龄可影响术后立体视的获得,其中发病年龄起关键作用。为了提高术后双眼视觉的重建,成人外斜视手术宜早不宜晚。     

Visual function after primary posterior chamber intraocular lens implantation in pediatric unilateral cataract: stereopsis and visual acuity

PURPOSE: To investigate the association between binocular function and vision after cataract removal and primary posterior chamber intraocular lens (PC-IOL) implantation in children with unilateral cataract and to identify visual function differences according cataract type. METHODS: Clinical records of 2- to 6-year-old patients with unilateral cataract removal and primary PC-IOL implantation were reviewed retrospectively. Visual acuity and ocular alignment were measured. Sensory fusion was assessed with the Worth 4-dot test, and stereoacuity with the Titmus stereo test. Cataracts were classified according to cause, lens opacity location, age at onset, and presence of strabismus. Clinical characteristics of patients who obtained good visual function were identified. RESULTS: Forty-seven patients were included. Among 22 (46.8%) with good vision (20/40 or better), only 6 (27.3%) achieved good binocular function (the presence of fusion and 100 seconds of arc or better of stereoacuity). Visual acuity was better in eyes with good binocular function (p=0.002). No other variables were significant for achieving good binocular function. CONCLUSIONS: The removal of unilateral cataract in a visually immature child can result in a combination of good visual acuity and binocular function. Good binocular function is closely related to good visual acuity.     

斜视治疗应重视双眼视觉功能的恢复

斜视治疗的主要目的应是改变或恢复眼球运动和知觉方面的病理状态,手术的目标应该包括消除复视和混淆视,这样不仅患者外观和心理状态可得到改善,而且相当多的患者可恢复双眼视觉功能,部分患者可扩大周边双眼视野。我们应该深入研究和了解患者手术前、后的双眼视觉,并将立体视觉和双眼融合功能检查作为常规项目,推广使用三棱镜遮盖法;临床检查工作应深入细致。只有视轴偏斜得到矫正,患者获得双眼视觉,斜视治疗的效果才能得到巩固。(中华眼科杂志,2005,41：577-580)     

成人共同性水平斜视术后双眼视功能重建的研究

目的探讨成人水平性共同性斜视矫正术后双眼视功能的重建。方法分析45例年龄为18～50岁共同性水平斜视矫正手术后的双眼视功能。结果本组患者术前最佳矫正视力≥0．3，双眼最佳矫正视力相差≤2行，术前均无双眼视功能。斜视矫正术后6周，40例（88．89％）有不同程度的近立体视，其余5例（11．11%）术后无双眼单视，但仅2例经同视机检查有Ⅲ级功能。结论成人共同性斜视术后不仅达到美容目的，而且还可获得一定程度的双眼视功能。     

婴幼儿期外斜视术后眼位及双眼视功能的影响因素

目的:研究影响婴幼儿期外斜视术后眼位及双眼视功能的相关因素.方法:选取于我院眼科住院诊治行外斜视矫正术的患儿90例,收集其相关临床资料并术后回访1a,分析其影响术后眼位及双眼视功能的相关因素,包括发病年龄、斜视类型、手术年龄、就诊年龄、手术前远立体视功能、手术前近立体视功能、手术后眼位等.结果:单因素及Logistic回归多因素分析结果提示:斜视类型、远期眼位、术前同视机立体视功能是婴幼儿期外斜视术后眼位及双眼视功能的影响因素(P＜0.05),而性别、发病年龄、手术年龄、术前Timus立体视功能、斜视临床分型不是婴幼儿期外斜视术后眼位及双眼视功能的影响因素(P＞0.05).结论:婴幼儿期行外斜视术的斜视类型、远期眼位、术前同视机立体视功能是影响术后眼位及双眼功能的主要影响因素,为术后恢复的患儿眼位及双眼视功能提供一定的治疗依据.     

斜视手术前后双眼视觉的临床研究

目的探讨斜视对双眼视觉的影响及不同双眼视检查方法的评价。方法89例共同性斜视分为间歇性外斜、恒定性外斜及恒定性内斜3组。定量测量斜视度；检查双眼视觉状态及视网膜对应情况；测定远近立体视锐度。并观察斜视手术前及手术后1周、1月的斜视度、双眼视觉状态及远、近立体视锐度变化。结果3组术后双眼视功能较术前均有明显改善（P〈0．05），术后1周与1月双眼视功能的差异无统计学意义（P〉0．05）；恒定性斜视术后立体视恢复好于间歇性外斜视，且近立体视恢复好于表视；立体视检查非随机点画片（Titmus与Optec3500）与随机点画片（TNO）检查结果的差异有统计学意义（P〈0．05）；线状镜较Worth四点检测阳性率高；大于9岁患者术后双眼视觉较术前增加32％。结论斜视手术是恢复、重建双眼视觉的有效方法，不同检测方法结果不一致，需综合考虑。     

知觉性内/外斜视与视力障碍发病年龄关系的研究

目的 研究知觉性内斜视或外斜视的发生与视力障碍发病年龄的关系。方法 回顾性分析169例知觉性斜视的临床资料,包括视力障碍的发病年龄、病因和知觉性斜视的类型等。结果 169例知觉性斜视中34例先天性视力障碍(20％),其中20例(59％)发生知觉性内斜视,14例(41％)发生知觉性外斜视;135例(80％)获得性视力障碍,其中21例(16％)发生知觉性内斜视;114例(84％)发生知觉性外斜视。两组间有显著性差异,x~2=27.67,P<0.01。86例视力障碍(51％)因白内障所致,其中无晶状体者64例(74％)。结论 先天性视力障碍(发病年龄≤6个月)主要发生知觉性内斜视,获得性视力障碍(发病年龄>6个月)主要发生知觉性外斜视。白内障是导致知觉性斜视最常见的原因。     

Presence of Fusion in Albinism after Strabismus Surgery Augmented with Botulinum Toxin (Type A) Injection

It is commonly accepted that albino patients with strabismus rarely achieve binocularity and depth perception after strabismus surgery. The presence of retino-geniculo-cortical misrouting, a hallmark of the visual system in albinism, does not necessarily cause total loss of binocular vision, however, not even in albino patients with strabismus. Recently some degrees of stereopsis were reported in albinism patients with minimal clinical nystagmus, if any, in the absence of strabismus. It is possible that patients with albinism and strabismus have binocular visual potential which appears after strabismus correction and provides appropriate postoperative alignment in the long term. Here we present two cases of clinically diagnosed oculocutaneous albinism, an 18-year-old girl and a 16-year-old boy, both with exotropia ≥40 prism diopter, who gained acceptable alignment and fusion after surgical correction of their strabismus as demonstrated on Bagolini testing. In cases of albinism accompanied by visual pathway abnormalities and strabismus, binocular visual potential is not impossible, and some levels can be expected. Thus, these patients, like other cases of strabismus, may benefit from treatment of strabismus at an earlier age to achieve appropriate alignment, cosmetic satisfaction, and a possibly increased chance of fusion.     

Fusion ability lost and regained in visual adults

The case reports are given of two adult patients who lost all fusion ability and had the signs and symptoms of central fusion disruption and intractable diplopia. Both patients suffered binocular sensory deprivation for several years caused by a combination of a traumatic cataract and uncorrected unilateral aphakia. One patient had a posterior chamber intraocular lens inserted to correct the aphakia and the other patient had a contact lens. Aniseikonia was not appreciated by either patient and did not appear to contribute to the fusion problem. Adjustable strabismus surgery, in both patients, and prism glasses, in one, enabled approximate superimposition of the visual axes.After several months, both patients began to develop some fusion with small amplitudes and the vertical bobbing typical of central fusion disruption disappeared.Dedicated to Dr. G.K. von Noorden on the occasion of his 60th birthday     

Preliminary report: Fixation behavior and reading strategies in dyslexic and normally reading children as assessed by the scanning laser ophthalmoscope

Abstract

Introduction: One goal of pre-operative sensorimotor testing is to determine fusion potential. Potential for recovery of binocularity following surgical repair of strabismus is inversely correlated to duration of misalignment. The purpose of this study was to determine binocular vision outcomes in long-standing, large-angle, constant exotropia, when the pre-operative sensorimotor exam predicts poor sensory outcome.

Methods: Patients with constant exotropia >35Δ, present for ≥20 years, and scheduled to undergo strabismus surgery were recruited. Subjects were sorted into 3 groups based on pre-operative sensorimotor results. Group A had evidence of fusion pre-operatively, Group B demonstrated suppression on all tests, and Group C demonstrated paradoxical diplopia on at least one test.

Results: Twenty patients were included: 11 in Group A, 5 in Group B, and 4 in Group C. Binocular vision was regained following surgery by 100% in Group A, 80% in Group B, and 50% in group C.

Conclusion: Surgical realignment leads to improvements in binocular vision in most patients, even in the case of very long-standing, large, constant deviations. The presence of paradoxical diplopia or dense suppression pre-operatively does not preclude a good sensory outcome.     

Effects of Duane's retraction syndrome on sensory visual development

PURPOSE: To study the effects of Duane's retraction syndrome on sensory visual development. METHODS: Monocular and binocular visual function and ocular motility have been studied and pattern reversal visual evoked potentials recorded from 22 patients with Duane's syndrome aged from 4 to 55 years. RESULTS: Sixteen of the patients maintained binocular single vision using an abnormal head posture. All had normal visual acuities in both eyes. The 12 adults in this group had a mean stereoacuity of 78 seconds of arc with the mus stereotest and 101 seconds of arc with the TNO test. Both these values were significantly worse than for normal adults with a similar age range. The binocular VEPs from these patients showed enhancement of the binocular P100 VEP amplitude compared to the mean monocular P100 amplitude when they used their head posture but, unlike in normal subjects, this binocular enhancement was not reduced significantly after the age of 5. Six patients had lost binocular function and had a manifest convergent squint. Of these, 4 were anisometropic. VEPs in this group showed mildly delayed P100 latencies in the affected eye with asymmetric amplitudes even though their amblyopia had been successfully treated by patching and only one patient had a substantially reduced acuity. In neither group was there any relationship between the degree of restriction of ocular motility and the sensory changes. CONCLUSION: Patients with Duane's syndrome who retain binocular single vision show abnormal binocular visual maturation after the age of 5 years. This results in reduced stereoacuity in the absence of amblyopia.