The results of clear lens extraction for anisometropia treatment in patients with high myopia and unilateral cataract

PURPOSE: To evaluate results of clear lens extraction for treatment of anisometropia in patients with bilateral high myopia and unilateral cataract. MATERIAL AND METHOD: 23 patients with bilateral high myopia who underwent clear lens extraction with PC IOL implantation to treat high anisometropia after cataract surgery in the other eye were observed in our study. Preoperative refractive error was from -8.0 D to -19.0 D (spherical equivalent). RESULTS: Anisometropia after operations in both eyes was from 0.0 D to 3.5 D. No serious complications after operations such as retinal detachment were observed. CONCLUSION: Clear lens extraction with PC IOL implantation in highly myopic eyes can be used for correction of high anisometropia after cataract surgery in the other eye.     

Pseudophakic ametropia managed with a phakic posterior chamber intraocular lens

We report the use of a phakic posterior chamber intraocular lens (IOL) to correct pseudophakic ametropia. Two eyes of 2 patients developed ametropia after unilateral phacoemulsification and IOL implantation. The manifest refraction was -6.00 -0.50 x 50 in the first patient and +4.50 -1.00 x 15 in the second. Both patients were bothered by the induced anisometropia and had posterior chamber phakic IOL implantation in the pseudophakic eye. Postoperatively, uncorrected visual acuity improved from 20/400 to 20/30 in the first patient and from 20/200 to 20/40 in the second patient. The manifest refraction was -0.50 -0.75 x 55 and +1.50 -1.50 x 30, respectively. No complications were noted. Implantation of a phakic posterior chamber IOL may be an alternative to currently available methods of managing pseudophakic ametropia.     

超声乳化术治疗中青年单眼白内障临床分析

目的探讨白内障超声乳化吸除人工晶状体植入术治疗中青年单眼白内障临床疗效及手术适应证。方法共26例（26只眼）,其中男11例（11只眼）,女15例（15只眼）,年龄21-48岁,平均37.5岁。除1例（1只眼）术前视力为0.6外,其余手术眼视力均〈0.4,而非手术眼视力均在0.6以上。其中合并远视力3只眼,合并有高度近视9只眼（其中准分子激光治疗术后2只眼,有角膜散光〉-1.00 D者3只眼）,合并糖尿病3只眼,合并葡萄膜炎3只眼,眼外伤2只眼,玻璃体切割术后1只眼,无明显诱因3只眼。术前常规检查及人工晶状体度数测量,局麻下行白内障超声乳化吸除人工晶状体植入术。其中3例（3只眼）植入散光型人工晶状体（Acrysof Toric IOL）。26例患者非手术眼佩戴隐形眼镜者7例（7只眼）,2例（2只眼）行准分子激光原位磨镶术。结果所有患者视力均有不同程度提高,其中无明显诱因者术后视力达1.2。3例（3只眼）Toric人工晶状体植入术者,不仅视力提高,追踪半年以上,人工晶状体表袋内视轴稳定,无明显不适。屈光参差较大者,非手术眼屈光不正配戴隐形眼镜或准分子激光治疗,均获得较好双眼单视功能。结论超声乳化及人工晶状体植入术治疗中青年单眼白内障患者,效果肯定,无明显并发症;根据中青年年龄特点、非手术眼屈光度情况及工作生活需要,可适当放宽手术眼在视力上的适应证。而对于术后双眼屈光参差较严重者,可根据非手术眼屈光度配戴隐形眼镜或行准分子激光治疗,以建立双眼单视功能,提高生活质量。     

Refractive surgery in patients with high myopic anisometropia

PURPOSE: To assess the efficacy and safety of LASIK in patients with high myopic anisometropia and to provide specific screening guidelines for anisometropic patients undergoing refractive surgery. METHODS: Twenty-six eyes of 16 patients with high myopic anisometropia (>3.0 diopters) were enrolled in this study. Complete pre- and postoperative ophthalmologic and orthoptic examinations were performed. The preoperative orthoptic examination was done with glasses and contact lenses. Twenty-two eyes of 13 patients underwent uncomplicated LASIK; the second eye was treated 2 weeks after the first eye. Patients were examined 1 day, 7 days, and 1, 3, 6, and 12 months after surgery. RESULTS: Thirteen patients obtaining good results at red glass bar test (RGB) underwent LASIK without postoperative diplopia; four showed an improvement of the sensorial assessment. Three patients were excluded from surgery because of diplopia with RGB values <4 to 5. LASIK temporarily induced diplopia in the suppressed eye of one patient; however, the diplopia disappeared after surgery of the fixating eye. CONCLUSIONS: Patients with high myopic anisometropia and a weak sensorial state who undergo refractive surgery may be at risk for postoperative diplopia. We suggest clinical guidelines to reduce the occurrence of this complication.     

Mirror image myopic anisometropia in two pairs of monozygotic twins.

Two sets of monozygotic twins with mirror image myopic anisometropia are reported. The first set were two boys aged 1 year 8 months. There was a right eye myopic anisometropia in one twin, and a left eye myopic anisometropia in the other. The differences in refractive power between both eyes were 11.6 and 7.6 dpt, respectively (spherical equivalent). The second set were two 6-year-old boys. The right eye had myopic anisometropia in one twin, while the left eye was affected in the other. The differences in refractive power between both eyes were 6.5 and 3.7 dpt, respectively (spherical equivalent). Exotropia was recognized in 3 cases. Previously only two sets of monozygotic twins with mirror image myopic anisometropia have been reported. Monozygotic twins with mirror image myopic anisometropia are extremely rare.     

超声乳化术摘除晶状体治疗高度近视的屈光参差

目的 评价高度近视眼经超声乳化摘除晶状体联合植入折叠式人工晶状体治疗屈光参差的有效性和安全性.方法 选择一眼已行白内障手术另一眼为高度近视眼者48例,经颞侧透明角膜切口,行超声乳化联合折叠式人工晶状体植入.随访6～36个月,平均(23.5±3.2)个月.结果 术后3个月,最佳矫正视力0.2～0.4者2眼(4.2%),0.5～1.5者46眼(95.8%).术眼平均近视度数从术前的(-12.94±4.05)D降至术后3个月时的(-1.42±0.61)D(P=0.000),平均屈光参差度数从术前的(-10.56±4.07)D降至术后3个月时的(-1.04±0.60)D(P=0.000),差异均有统计学意义.术前与术后3个月的角膜散光度数差异无统计学意义(P=0.745).术后有1眼一过性眼压升高,4眼轻度角膜水肿,随访中5眼(10.4%)晶状体后囊膜混浊,无其他手术并发症.结论 中、老年白内障患者在单眼行白内障摘除术后,对侧眼尽早行超声乳化联合折叠式人工晶状体植入术对矫正高度近视屈光参差具有迅速恢复双眼视功能的效果,并发症少,疗效确切.     

优势眼与近视的关系研究

目的 :研究优势眼眼别与其两眼中近视性屈光程度较大眼的眼别关系。方法 :16 5个受试者 ,按照双眼屈光参差的程度分双眼屈光无显著差异组、生理性屈光参差组与病理性屈光参差组三组。在医学验光基础上 ,结合简化的卡洞法与拇指法判别双眼中的优势眼眼别。结果 :①对于所有个体 ,优势眼眼别与双眼中近视性屈光程度稍大眼眼别显著相关 (Z =- 3.6 2 1,P <0 .0 0 0 1)。②双眼屈光无差异组优势眼眼别与其两眼中近视性屈光程度较大眼眼别显著相关 (P <0 .0 0 0 1) ,但在生理性屈光参差组与病理性屈光参差组 ,两者均无显著相关 (P >0 .0 5 )。③各组均以右优势眼居多 ,右眼屈光不正较大者居多。结论 :优势眼的选择可能早于双眼近视性屈光参差的发生 ,而近视性屈光参差可能影响优势眼的选择     

单焦点IOL植入术后RGPCL诱导屈光参差后的视觉质量

目的探讨在年龄相关性白内障手术中,应用单眼视概念,双眼植入不同度数单焦点人工晶状体（IOL）的可行性。方法前瞻性非随机临床对照研究。选取双眼白内障摘除联合单焦点IOL植入术后符合标准的患者40例（80眼）,做2种矫正处理：以硬性透氧性角膜接触镜（RGPCL）一眼矫正为正视,一眼矫正为-2.0 D近视,即屈光参差状态或双眼矫正为正视,即全矫状态。分别检测其远方三级视功能、近立体视及远、近对比敏感度,并对生活满意度进行调查评估。对数据进行配对t检验,配对符号秩和检验或χ2检验。结果立体视检查显示：矫正状态远融合功能、立体视优于屈光参差状态（χ2=9.03、16.88,P<0.01）,屈光参差状态的近立体视优于矫正状态,差异有统计学意义（Z=-3.230,P<0.01）。但屈光参差状态仍有相当数量患者存在远立体视,矫正状态有近立体视患者数量较少。对比敏感度检查显示：在低频段,无论明亮还是昏暗条件,2种状态下远近对比敏感度差异无统计学意义;在中高频段,矫正状态远对比敏感度优于屈光参差状态（t=0.37、0.51、0.35、0.46、0.44、0.46、0.51、0.40,P<0.01）,而屈光参差状态近对比敏感度优于矫正状态（t=0.18、0.34、0.49、0.38、0.20、0.34、0.24、0.38,P<0.01）。生活质量调查显示,屈光参差状态总体视力满意度较全矫状态高,差异有统计学意义（t=-3.05,P<0.01）。结论年龄相关性白内障术后双眼诱导屈光参差,视远视觉质量下降,但仍有相当数量患者存在远立体视,视近视觉质量明显提高,生活满意度提高。     

Use of AcrySof acrylic foldable intraocular lens for secondary implantation in children.

PURPOSE: Secondary intraocular lens (IOL) implantation is an increasingly viable option in the management of pediatric aphakia. We report our experience of secondary IOL implantation in pediatric patients using the AcrySof (Alcon Surgical, Fort Worth, Texas) 3-piece foldable lenses through a small incision. METHODS: We reviewed the records of all our patients < 18 years undergoing secondary IOL implantation of the AcrySof lens from 1997 to 2001. All patients with a minimum of 6 months follow-up were included. Records were analyzed for age at surgery, postoperative acuity change, postoperative refractive error and anisometropia, surgical complications, and length of follow-up. RESULTS: Fifty-five eyes of 36 patients were included in the review. Mean age at surgery was 7.4 years (1.1 to 15.4), and mean follow-up was 28 months (6.3 months to 5 years). Vision decrease > 2 lines was noted in 3 eyes (5.8%) during the follow-up period. Complications included IOL decentration in 3 eyes (5%), wound leak in 3 eyes (5%), secondary membrane formation in 5 eyes (9%), pupillary block glaucoma in 1 eye (2%), and ptosis in 1 eye (2%). Four eyes (7%) required reoperation for complications. Mean postoperative refractive error was -0.1 +/- 3.2 diopters (D), and mean anisometropia was 2.01 +/- 1.44 D. Glaucoma subsequently developed in 6 eyes (11%), 2 of which required surgical correction. CONCLUSIONS: Secondary placement of the AcrySof IOL in the ciliary sulcus is a safe and effective method to correct aphakia in pediatric patients with adequate capsular support. The incidence of complications requiring reoperation is low.     

屈光参差与主导眼的相关性研究

目的：研究主导眼与屈光参差的关系,探讨屈光参差的成因。方法：屈光参差患者486例972眼,按照其屈光参差的性质不同,将其分成远视性、近视性和混合性三组。运用睫状肌麻痹剂散瞳,行电脑验光测双眼屈光度,应用简化的卡洞法测定双眼中的主导眼眼别。分析各组数据中屈光度大的眼别与主导眼眼别的相关性。结果：远视性屈光参差组99例198眼,主导眼别与屈光程度小的眼别有显著相关性（Z=-4.116,P〈0.01）,即非主导眼的屈光度大于主导眼。近视性屈光参差组312例624眼,主导眼眼别与屈光程度小的眼别无相关性（Z=-0.304,P〉0.05）。混合性屈光参差组75例150眼,主导眼眼别与近视眼眼别显著相关（Z=-3.645,P〈0.01）。即主导眼屈光状态多为近视眼别。结论：远视性和混合性屈光参差的形成与主导眼所致的双眼发育不平衡有关。     

Stereopsis in refractive surgery

PURPOSE: To examine stereopsis in myopic refractive surgery patients undergoing sequential bilateral and unilateral treatment. DESIGN: Prospective, observational, cohort study. METHODS: Setting: Clinical practice. Patients: Eighty-three patients were studied; 55 had sequential bilateral and 28 had unilateral treatment. Mean age was 32 years. Stereopsis was measured using a multitarget red-green anaglyph stereo vision test. Only patients with fine preoperative stereopsis were included in the study. Repeat measurements were taken one week laser-assisted in situ keratomileusis (LASIK) or three weeks laser epithelial keratomileusis (LASEK) after treatment of one eye in all patients. Further measurements were taken at six and 12 weeks in unilaterally treated patients and after treatment of the fellow eye in bilaterally treated patients. RESULTS: A total of 38.6% of patients retained fine stereopsis (28 to 41 seconds of arc) over a range of anisometropia from 0.625 to 4.375. Moderate stereopsis (66 to 526 seconds of arc) was recorded 28.9% in the presence of 1.375 to 5.525 diopters of anisometropia. Poor/absent stereopsis (< or =2000 seconds of arc) was found in 32.5% in the presence of 2.1 to 8.0 diopters of anisometropia. A strong correlation was found between stereopsis and anisometropia, but interpatient variability was found. Uncorrected visual acuity (UCVA) in the untreated eye of > or =20/200 was associated with retention of fine stereopsis. Unilaterally treated patients showed improvement in stereopsis at six weeks after surgery. Sequential bilateral treatment had no deleterious effect on stereopsis. CONCLUSIONS: Loss of stereopsis was strongly correlated with anisometropia. UCVA in the untreated eye was a good indicator of postoperative stereopsis. Stereopsis improved during the postoperative adaptation period in unilateral treatments. Bilateral sequential treatment has no long-term effect on stereopsis.     

Interocular axial length difference and age-related cataract

PURPOSE: To evaluate interocular differences in axial length and its relation to increasing axial length and postoperative refractive predictability in patients with age-related cataract. SETTING: Moorfields Eye Hospital, London, United Kingdom. METHODS: Preoperative biometry and postoperative refractive outcomes were analyzed in a consecutive series of 1537 patients who had uneventful bilateral phacoemulsification. In 1379 patients with bilateral data, the difference in axial lengths between eyes and the magnitude of postoperative anisometropia were compared between 1.0 mm incremental groups of axial length using the longer eye as the index eye. The postoperative refraction prediction error in 1457 left eyes was assessed in similar axial length groups. RESULTS: The difference in axial length was 0.3 mm or greater in 331 patients (24%). Axial length asymmetry between eyes increased with an increase in axial length in the index eye (P<.001). The 95th centile of the axial length difference was 0.5 mm when the longer eye was 22.0 mm or less and 4.0 mm when it was 28 mm or greater. There was also an increase in postoperative anisometropia with increasing axial length (P = .003). The median was 0.34 D (interquartile range [IR], 0.25-1.11) when the longer eye had an axial length of less than 28.0 mm and 0.66 D (IR, 0.16-0.66) when the longer eye had an axial length of 28.0 mm or more. In left eyes, there was an increase in biometry prediction error with an increase in axial length (P = .006). CONCLUSION: An increase in axial length was associated with greater asymmetry between eyes and more postoperative anisometropia, especially in eyes with an axial length greater than 28.0 mm.     

后房型人工晶体更换术矫治人工晶体术后屈光误差

本文采用后房型人工晶体更换术矫治 ７ 例 （７ 眼） 因人工晶体植入术后所致较大度数屈光误差及屈光参差。结果： 手术中顺利取出原后房型人工晶体 ６ 例 （６ 眼）， １ 例 （１ 眼） 原人工晶体下襻与囊袋间固定粘连难以旋转取出， 剪断下襻后取出含人工晶体上襻的光学部， 后均顺利植入矫正后房型人工晶体。术后随访 ６ 个月至 ３ 年， 裸眼视力 ０４～１０， 双眼屈光力差０～１０ Ｄ。患者均可适应工作及生活需要。利用后房型人工晶体更换术为解决因人工晶体所致的难以适应的屈光误差及屈光参差提供了有效的矫治手段。     

Idiopathic amblyopia

Two children without strabismus, anisometropia, or a history of form-vision deprivation who had normal stereoacuity were amblyopic in one eye. The amblyopia responded to occlusion treatment of the sound eye and visual acuity decreased again after cessation of therapy. There is no explanation for this amblyopia. It is possible, however, that binocularly provoked inhibition of the fovea of one eye was conditioned during infancy by an amblyopiogenic condition such as anisometropia. This inhibition may have continued to be triggered by binocular vision in these patients, even though the original obstacle to fusion was no longer apparent.     

Piggyback lens implantation for anisometropia in pseudophakic eyes

OBJECTIVE: Long standing pseudophakia or previous laser capsulotomy make lens exchange for anisometropia or incorrect target refraction difficult. Piggyback lens implantation might be a less traumatic surgical alternative. PATIENTS AND METHODS: Eight patients had a secondary posterior chamber lens implant (PMMA) into the ciliary sulcus. Lens power was estimated by the preoperative refraction according to the refractive vergence formula and was controlled intraoperatively by an automatic refractometer. Surgical access minimized preoperative astigmatism. RESULTS: All patients had disturbing anisometropia of 4.57+/-2.86 D and had undergone cataract surgery 1-13 years previously. Piggyback lens implantation was combined with surgical aspiration of the secondary cataract in three patients. Due to recurrent PVR retinal detachment, one patient received a silicon oil refilling procedure and piggyback lens implantation. The preoperative spherical equivalent was -3.34+/-4.9 D. Mean follow up time was 16.6 months. Postoperative anisometropia was reduced to 1.1+/-1.01 D. The mean absolute deviation from target refraction was 0+/-0.92 D. Elevated IOP or secondary cataract formation in the lens interface were not observed. One patient developed pigment dispersion. CONCLUSION: Secondary piggyback lens implantation into the ciliary sulcus in front of an existing posterior chamber lens is a safe and effective refractive surgical procedure for special cases with predictable refraction.     

The Quest for Spectacle Independence: A Comparison of Multifocal Intraocular Lens Implants and Pseudophakic Monovision for Patients with Presbyopia

ABSTRACT

We performed a literature review comparing multifocal intraocular lens (IOL) implantation with pseudophakic monovision to treat presbyopia. Multifocal IOLs utilize refractive or diffractive principles to treat both distance and near vision, with a single lens implant. Monovision uses traditional monofocal lens implants to treat the dominant eye for emmotropia, and the non-dominant eye for myopia. This planned anisometropia is designed to enhance intermediate or near vision. Generally, distance vision was similar with both types of lens implantation, near vision was better with multifocal IOLs, and intermediate vision appeared to be better in the monovision group. For patients requiring cataract surgery, both multifocal IOLs and monovision appear to address presbyopia with a high level of patient satisfaction. More patients reported complete spectacle independence with multifocal IOLs, but more glare and halos were reported by multifocal IOL patients as well.     

A longitudinal study of a population based sample of astigmatic children. II. The changeability of anisometropia

The variability of anisometropi in a sample of 310 children with astigmatism at the age of 1 year was longitudinally studied during a 3-year period between 1 and 4 years of age. The prevalence of anisometropia of 1 D or more at each year level was rather stable. When individual cases were examined we found that between the first and the last test session 19 of the 33 children with anisometropia at the first test session had become non-anisometropic and were substituted with 14 new cases which were non-anisometropic at the age of 1 year. In general, less than half of the cases, at all levels of anisometropia, remained anisometropic throughout the whole test period. We also found that children with anisometropia persisting through the whole test period were at considerable risk, about one out of four, of developing amblyopia. There was no simple relationship, however, between anisometropia at a certain age level between 1 and 4 years and amblyopia and/or strabismus. Non-persisting anisometropia in an emmetropizing eye is in most cases a benign sign and not connected with an increased risk for developing amblyopia.     

Association of ocular dominance and anisometropic myopia

PURPOSE: To determine the association between ocular dominance and degree of myopia in patients with anisometropia. METHODS: Fifty-five subjects with anisometropic myopia were recruited. None of them had amblyopia. Refractive error and axial length were measured in each subject. Ocular dominance was determined using the hole-in-the-card test and convergence near-point test. RESULTS: There was a threshold level of anisometropia (1.75 D) beyond which the dominant eye was always more myopic than the nondominant eye. Of the 33 subjects with anisometropia of < or =1.75 D, the dominant eye was more myopic in 17 (51.5%) subjects. Dominant eyes, determined by the hole-in-the-card test, had a significantly greater myopic spherical equivalent (-5.27 +/- 2.45 D) than nondominant eyes (-3.94 +/- 3.10 D; P < 0.001). Dominant eyes also had a longer axial length than nondominant eyes (25.15 +/- 0.96 mm vs. 24.69 +/- 1.17 mm, respectively; P < 0.001). The difference was more evident in those subjects with higher anisometropia (>1.75 D), but was not significant in those with lower anisometropia (< or =1.75 D). Similar results were obtained using the convergence near-point test. CONCLUSIONS: The present study shows that the dominant eye has a greater degree of myopia than the nondominant eye in subjects with anisometropic myopia. Taking ocular dominance into account in the design of randomized clinical trails to assess the efficacy of myopia interventions may provide useful information.     

The prevalence of amblyogenic factors in children with persistent congenital nasolacrimal duct obstruction

Background

To evaluate the prevalence of amblyopia risk factors in children that underwent probing for persistent congenital nasolacrimal duct obstruction (CNLDO).

Methods

The medical records of children with CNLDO (after 1 year of age) that underwent probing were reviewed. Amblyopia risk factors, based on the American Association for Pediatric Ophthalmology and Strabismus referral criteria in 2013, were sought in the patients? records before probing. The proportion of the patients with anisometropia >1.5 diopters (D) was separately calculated. In unilateral cases of CNLDO, sphere, astigmatism, and spherical equivalent of the eyes with CNLDO were compared with contralateral eyes in order to assess the effect of CNLDO on refractive error. In the follow-up examinations, the success of the probing or the need for additional procedures (Crawford intubation, Monoka intubation, or dacryocystorhinostomy) was evaluated. The prevalence of anisometropia between ‘successful probing’ and ‘failed probing’ groups was compared.

Results

A total of 433 cases were included in the study. 41 cases (9.46 %) had amblyopia risk factors. Twenty-four cases (5.5 %) had anisometropia >1.5 D (spherical or cylindrical). In unilateral cases of CNLDO, the sphere and spherical equivalent of the eyes with CNLDO were significantly greater than those of the contralateral eyes (p?p?=?0.03).

Conclusions

The findings of greater prevalence of anisometropia >1.5 D (compared with the prevalence in the general population) and significantly greater sphere and spherical equivalents in the eye with CNLDO (compared with contralateral eye) in unilateral cases with CNLDO, suggested some relationships between anisometropia and long-term untreated CNLDO. The finding of more anisometropia in failed probing cases may support the theory of structural abnormality as an explanation for the possible relationship between congenital nasolacrimal duct obstruction and anisometropia.     

Amblyopia in myopia in patients with strabismus and without strabismus

PURPOSE: To determine factors, which have influence on presence of strabismus among myopic patients with amblyopia. MATERIAL AND METHODS: Material covers 21 myopic patients with amblyopia, aged 6-15. All children presented have a different amount of anisometropia, 12 of them had strabismus. Authors, compared the group of patients with amblyopia and strabismus (12) with the group of patients with pure anisometropic amblyopia (9), according to the following criteria: age of presentation, best corrected visual acuity, mean refraction error of amblyopic eye, mean amount of anisometropia, percentage of patients with central fixation and binocular vision. RESULTS: Patients with strabismus presented oneself earlier than patients without squint. Best corrected visual acuity was better in patients without strabismus. Refraction error in both groups has similar value. Amount of anisometropia was slightly smaller in the group with squint. Central fixation and binocular vision were better preserved among patients without strabismus. Authors didn't find the following correlations too: correlation between amount of anisometropia and amount of amblyopia in both groups, correlation between amount of anisometropia and the amount of the deviation of squinting eye, correlation between depth of amblyopia and the amount of deviation of the squinting eye. CONCLUSION: It seems, that primary factor leading to presence of strabismus among patients with anisometropic myopia, is motor dysfunction of extraocular muscles.