Treatment of manifest latent nystagmus

Eight patients with manifest latent nystagmus, as noted by ocular movement recordings, were examined for nystagmus reduction after surgical or optical treatment. Seven of the patients had strabismus. Five patients underwent strabismus surgery, had no tropia postoperatively, and the manifest latent nystagmus converted to latent nystagmus. Four of these five patients subsequently showed improvement in binocular visual acuity. Three patients received optical treatment; one had accommodative esotropia and, with appropriate spectacle correction, the manifest latent nystagmus was converted to latent nystagmus with improved vision. In the other two patients the manifest latent nystagmus lessened after correction with appropriate spectacles; binocular visual acuity of one of these patients improved. The possibility of converting manifest latent nystagmus to latent nystagmus by strabismus surgery is a reasonable surgical goal. In patients with manifest latent nystagmus and strabismus, surgical or optical alignment of the eyes decreases the nystagmus intensity and may also improve binocular visual acuity.     

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。     

Positive angle kappa in albinism.

BACKGROUND: Albinism is an inherited disorder of deficient melanin production. There is a high prevalence of strabismus in patients with albinism. We investigated the prevalence of a positive angle kappa in patients with albinism and report its effect on assessment of binocular alignment. METHODS: We retrospectively reviewed the charts of 207 consecutive patients with the diagnosis of albinism seen at the University of Minnesota between 1984 and 2002. Angle kappa and alignment using prism and alternate-cover test (PACT) and Krimsky measurements were recorded. RESULTS: In 99.6% of our patients with albinism, angle kappa was noted to be positive. The mean difference between PACT and Krimsky measurements was 17.11 prism diopters in the more exotropic (or less esotropic) direction per Krimsky test. Because of the high prevalence of a positive angle kappa, esodeviations often appeared less and exodeviations appeared greater than when measured using PACT. CONCLUSIONS: Positive angle kappa can be considered another clinical feature of albinism. Consideration should be given to the effect of positive angle kappa on alignment as observed by Krimsky measurement when planning extraocular muscle surgery, particularly when preoperative sensory testing suggests binocular potential.     

Efficacy of spectacles in persons with albinism

INTRODUCTION: Patients with albinism have varying degrees of reduced vision, strabismus, iris transillumination, nystagmus, fundus hypopigmentation, and foveal hypoplasia. High refractive errors are common, but reduced vision persists due to nonrefractive factors, causing reluctance by some clinicians to prescribe spectacles. We sought to evaluate the effect of spectacle correction of refractive error on clinical findings and recorded compliance with refractive corrections, as little detailed data exist. METHODS: We prospectively examined 35 consecutive patients with albinism for whom glasses had been prescribed to determine if objective improvement in recognition visual acuity (VA), strabismus, anomalous head posture (AHP), fusion, or stereoacuity occurred with refractive correction. Parents or patients reported compliance with glasses wear (excellent: >75% of awake hours; good: 50-75% of awake hours; fair: 26-50% of awake hours; poor: <25%). RESULTS: Median age was 9.5 years (range: 3 to 30). Median refractive correction was 1.875 D spherical equivalent (range: -9.75 to +8.88 D). Glasses wear was initiated at a median age of 14 months (range: 3 months to 14 years). Mean binocular VA at distance was 20/80.9 corrected and 20/107.6 uncorrected ( P < 0.001). Mean VA at near was 20/28.4 corrected and 20/41 uncorrected ( P < 0.001). Mean strabismic deviation was 7.2 PD with glasses and 10.0 PD without glasses at distance ( P = 0.006) and 10.8 PD with glasses and 14 PD without glasses at near ( P = 0.042). Mean AHP at distance was 8.3 degrees with glasses and 7.3 degrees without glasses at distance ( P = 0.327) and 4.7 degrees both with and without glasses at near ( P = 0.308). Twenty-one patients had fusion with or without glasses, two had fusion only with glasses, and one patient had fusion only without glasses. The other patients did not have any detectable degree of fusion. Twenty-seven individuals had no stereoacuity with or without glasses, five had gross stereoacuity of 3000 seconds of arc both with and without glasses, and three had gross stereoacuity only while wearing glasses. Compliance was excellent in 29 patients, fair in four, and poor in two. CONCLUSION: This prospective study showed a significant improvement in corrected VA and alignment in persons with albinism, despite overall subnormal acuity. Some individuals also experienced improvement in binocular alignment and AHP. Compliance with spectacles was generally good. Therefore, refractive correction should be encouraged in persons with albinism as improvement in visual function is likely to occur.     

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。     

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）     

Ocular findings and visual evoked potential response in the Prader-Willi syndrome.

It has recently been suggested that aberrant misrouting of retino-geniculate-cortical (RGC) projections, a finding previously noted only in albinism, may be an additional feature of the Prader-Willi syndrome. To determine the prevalence of ocular abnormalities in patients with the syndrome and to look for evidence of misrouted RGC projections by means of testing of the pattern-onset visual evoked potential (VEP) response, we examined 12 patients with Prader-Willi syndrome, 8 albino subjects and 5 healthy control subjects. Ocular findings in the first group included telecanthus (in five subjects), strabismus, nystagmus, foveal hypoplasia, visual field defects and cataract. However, the VEP asymmetry typically seen in albinism was not noted in any of the patients with Prader-Willi syndrome. Our findings do not support previous claims of abnormal optic nerve fibre decussation in Prader-Willi syndrome.     

Vision defects in albinism.

We have examined the possible presence of color vision anomalies in 9 individuals (17 eyes, 1 blind) with fundus findings suggesting ocular albinism using the Ishihara plates, the 28-hue Roth test, and the Davico anomaloscope. Results indicate that four of these individuals show no sign of the anomalies expected in an albino in either of the two eyes. Of the remaining cases, two are simple deuteranomals in both eyes, according to Pickford's classification criteria. The rest have protanomaly; however, in these the deviation toward red appears in both eyes in only one subject, whereas in the other two subjects it appears in only one eye, their binocular color vision being basically normal. Our study shows that a large proportion of these albinos have photophobia, pendular nystagmus, strabismus, noticeable refractive errors (astigmatism and high myopia), and poor visual acuity [usually less than 6/30 (20/100) with correction]. The measurement of contrast sensitivity function (CSF) indicates that the frequency of 12 cpd cannot be perceived, even in binocular vision.     

A型斜视的临床表现和手术治疗

目的探讨A型斜视的病因、临床特征、手术治疗方法及疗效。方法分析自1995年1月至2003年12月1825例斜视中73例A型斜视病例的病历资料及治疗效果。所有患者依据是否伴有上斜肌功能过强、原位水平斜视及双眼视觉功能情况行上斜肌部分肌腱切除术或断腱术和/或水平直肌手术,术后随访时间6～18月,平均9月。结果A型斜视占同期斜视患者4.0%。在同期所有的A-V征中,A-外斜占21.2%,A-内斜占3.8%;术后眼位恢复正位62例（84.9%）,A征消失66例（90.4%）,术后58例获得立体视功能（包括术前3例存在立体视功能患者）。结论A型斜视是一种较常见的斜视类型,发病原因以斜肌功能异常为主,常合并水平斜视,应依据是否伴有斜肌功能异常及双眼视情况,选择不同的手术方式,可获得满意的术后效果。     

A型外斜视的临床表现和手术治疗

目的: 探讨 A型外斜视的病因、临床特征、手术治疗方法及疗效。方法: 分析自 1995- 01/2003- 12 收治的 1 825 例斜视中62 例 A 型外斜视病例的病历资料及治疗效果。所有患者依据是否伴有上斜肌功能过强、原位水平斜视及双眼视觉功能情况行上斜肌部分肌腱切除术或断腱术和 / 或水平直肌手术, 术后随访时间 6￣18( 平均 9) mo。结果: A型外斜视占同期斜视患者 3.4%。在同期所有的A- V征中, A- 外斜占 21.2%; 术后眼位恢复正位 52 例( 83.9%) , A征消失 56 例( 90.4%) , 术后 54 例获得立体视功能( 包括术前 3 例存在立体视功能患者) 。结论: A型外斜视是一种较常见的斜视类型, 发病原因以斜肌功能异常为主, 常合并水平斜视, 应依据是否伴有斜肌功能异常及双眼视情况, 选择不同的手术方式, 可获得满意的术后效果。     

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.     

部分调节性内斜视手术治疗及双眼单视功能相关因素研究

目的：探讨儿童部分调节性内斜视手术治疗及术后双眼单视功能恢复的相关因素。方法对56例部分调节性内斜视患儿戴全矫眼镜半年以后,手术矫治非调节因素所致的内斜视。手术量按照戴镜后残余斜视度设计。观察术后眼位及双眼单视功能恢复情况,对手术前后双眼单视功能改变及术后双眼单视功能恢复的相关性因素进行统计分析。结果术后末次随访时,48例（85.72%）戴镜正位（斜视角-8△～＋8△）,欠矫（戴镜斜视角〉＋8△）6例（10.71%）,2例（3.57%）过矫（戴镜斜视角〉-8△）。末次随访时同视机和Titmus立体视检查,手术后双眼单视功能较术前明显改善（P〈0.05）。非参数检验分析术后双眼视功能恢复的相关性因素,与发病年龄（P=0.02）、斜视发病至手术时间（P=0.003）、术后正位率（P=0.008）三项密切相关。结论当儿童部分调节性内斜视患儿戴全矫眼镜半年后眼位仍不能正位时,应尽早手术,术后仍需戴镜。     

Long‐term results of bilateral congenital cataract treated with early cataract surgery,aphakic glasses and secondary IOL implantation

Purpose: To evaluate the long‐term visual outcome after early surgery of bilateral dense congenital cataracts, aphakic correction with glasses and secondary intraocular lens (IOL) implantation around 2 years of age. Methods: The medical records of paediatric patients who underwent cataract extraction, aphakic correction and secondary IOL implantation from 1993 to 2004 at Seoul National University Children’s Hospital were reviewed retrospectively. Age at secondary IOL implantation, axial length (AL), best corrected visual acuity (BCVA), refractive error, ocular alignment, stereopsis, and postoperative ocular complications were recorded. Results: Thirty‐seven paediatric bilateral pseudophakic patients were identified with a mean follow‐up period of 81.4 months. Best corrected visual acuity of 20/40 or better were attained in 44.0% of eyes, and the median BCVA was 20/50. Preoperative factors associated with poor visual prognosis included cataract surgery after 8 weeks of age, interocular AL difference of 0.5 mm or more, and glaucoma. Amblyopic eyes showed more myopic change compared to fellow eyes. Good or moderate binocular function was achieved in 18.9% of all patients. Incidences of strabismus, glaucoma, posterior capsular opacity formation were 46.0%, 32.4% and 4.0%, respectively. Conclusion: Good postoperative BCVA and binocular function were achieved in most healthy children with bilateral dense congenital cataract and no posterior segment pathology. Early cataract surgery, aphakic correction with glasses and secondary IOL implantation around 2 years of age appears to be appropriate methods.     

Strabismus surgery in pseudophakic patients

PURPOSE: To analyze the results of strabismus surgery after previous cataract extraction with primary or secondary IOL implantation and to determine predicting factors of squint. MATERIAL AND METHODS: Eight patients with squint deviation after cataract surgery with primary or secondary IOL implantation were enrolled into this study. Each patient had complete ophthalmologic and orthoptic examination. Patients were divided into two groups. Group I consisted of 5 patients with secondary IOL implantation after traumatic cataract surgery, and group II consisted of 3 patients without ocular trauma, with primary IOL implantation. Five patients from both of groups had diplopia after IOL implantation. RESULTS: Strabismus surgery was performed in all cases. Surgery was combined with preoperative botuline toxin injections and Fresnel prism correction. Two patients were treated with adjustable suture technique. Treatment was successful in all cases. Five patients had no diplopia in primary position, two of them had occasional diplopia in secondary positions, while 3 patients with pour visual acuity achieved only esthetic effect. CONCLUSIONS: 1. Strabismus surgery in patients with pseudophakia is a complicated procedure which can optimize visual alignment, improve binocular vision and reduce diplopia. 2. Patients with diplopia or squint after IOL implantation ought to be informed about the possibility of strabismus surgery, both for diplopia and esthetic effect.     

Periodic alternating nystagmus associated with albinism

We examined a 73-year-old woman with the rare association of albinism and (presumably) congenital periodic alternating nystagmus. The mechanism of the nystagmus in this case is uncertain. Anomalous retinogeniculate pathways have been documented in albino animals. Periodic alternating nystagmus might occur in some patients with albinism if there are also anomalies in the pathways conveying visual information to the cerebellum and brainstem.     

直肌肌束部分转位移植矫正麻痹性斜视的临床观察

目的 探讨直肌肌束部分转位移植矫正麻痹性斜视手术方法和治疗效果.方法 总结27例麻痹性斜视行直肌肌束部分转位移植,并观察在术前、术后麻痹肌的运动情况、双眼视功能、眼球运动情况、眼位及复视消失情况等结果.结果 27例患者术后眼球运动功能有不同程度好转,除2例外全部过中线,转动1～2mm者12例、3mm者10例、4～5mm者2例、7mm者1例.术后被转位的肌肉运动正常.术后21例患者不同程度恢复了双眼视功能,其中具备Ⅰ度双眼单视功能13例,具备Ⅱ度双眼单视功能6例,2例有Ⅲ度双眼单视功能.6例同视机检测仍是单眼抑制.术后眼位正位22例,欠矫5～10度5例,23例复视消除,3例轻度改变注视方向也可消除复视.1例仍有复视不能耐受行二次手术.结论 直肌肌束部分转位移植可矫正麻痹性斜视眼位,消除复视,改善眼球运动,恢复部分双眼视功能,而且睫状肌血管分离保留可减少眼前段供血不足的危险,是目前安全、可行、有效地手术方法.     

儿童共同性外斜视手术治疗临床研究

目的评价儿童共同性外斜视的手术治疗效果。方法对84例年龄在4～12岁共同性外斜视进行手术治疗，并进行4～12个月随访观察。结果术后74例眼位正位，占手术总数88．10％；25例恢复了双眼单视功能，占术前无双眼单视功能者的50．00％，30例恢复立体视功能，占术前无立体视功能者的53．57％。结论手术在纠正儿童共同性外斜视眼的同时，能够有效地恢复部分患者的双眼单视功能和立体视功能。     

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.     

Stereopsis in patients with albinism: clinical correlates.

PURPOSE: A hallmark of albinism is excessive decussation of retinostriate projections at the optic chiasm. This misprojection might lead to abnormalities in the retinal correspondence and may account for the usual absence of stereovision. We report on 2 groups of patients with albinism who have either fine or gross stereopsis and compare the clinical findings of these groups to other patients with albinism with similar visual acuities but no stereopsis. METHODS: A retrospective chart review of patients with albinism was used to segregate those with a letter visual acuity of 20/100 or better in one eye, assessment of stereopsis, and strabismus < or = 10 PD. Forty-five patients were identified. Albinism type, best-corrected visual acuity, motility, Titmus vectograph stereoacuity, iris and macula transparency grades, and the presence or absence of both melanin and an annular reflex in the macula were tabulated. A comparison of the clinical characteristics of the groups with and without stereopsis was made. RESULTS: Those albino subjects who demonstrated stereopsis had better visual acuity, less iris transillumination, more frequent presence of melanin in the macula, less nystagmus, and less marked foveal hypoplasia than the albino subjects without stereopsis. No nystagmus was clinically detected in 5 patients with fine stereopsis. All these differences were statistically significant. Macular transparency grade was not significantly different between the groups. CONCLUSIONS: Patients with albinism who demonstrate stereopsis tend to have better visual acuity, more iris pigment, and more melanin pigment in the macula than their counterparts without stereopsis.     

Early surgery for infantile esotropia

AIM: To investigate the postoperative eye alignment and binocular visual function after early surgery for infantile esotropia. METHODS: Both the postoperative eye position and stereopsis were reviewed using the Titmus stereo test in nine patients who received uniocular medial rectus recession and lateral rectus resection under general anaesthesia before 8 months of age and were followed up for a minimum of 4 years. RESULTS: Orthophoria was attained in three cases, whereas esotropia was found in four patients. Dissociated vertical deviation was noted in two other cases at the final examination. Static stereoacuity was achieved in five cases. These results also showed that most infants in whom stereopsis was attained had satisfactory eye alignment during the follow up period and at the final examination. Infants who did not achieve stereopsis still had deviation throughout the follow up period. CONCLUSIONS: It was concluded that early surgery in infantile esotropia is beneficial to achieve binocular visual function, but it is necessary to confirm a stable angle of deviation with accurate preoperative evaluation, and to maintain good postoperative eye alignment throughout the follow up period.