Squint in monozygotic twins

In a group of monozygotic twins, in which at least one of the pair squinted, strabismus was observed in both twins in only about half of the cases. Within the concordant group there was variation in the way in which the anomaly became manifest.Author's address: Ophthalmological Clinic Academic Hospital Oostersingel 59 Groningen The Netherlands     

Vogt-Koyanagi-Harada disease in monozygotic twins

We encountered two cases of Harada's disease in monozygotic twins, and this is the first such report as far as could be determined. Case 1 was a 32-year-old woman who presented a typical clinical picture of Harada's disease. Seven years later, case 2 (the younger sister), also presented with the disease at 39 years of age. Case 2 had a transitional diffuse type of Harada's disease, which was possibly due to differences in her treatment. Both patients had papilledema. Since these twins both developed Harada's disease, it is suggested that hereditary factors including HLA type are very important in its development. The HLA type of both these patients was A2, A26, B51, B7, CW7, DR1, and DR4.     

Keratoconus and coexisting diseases in monozygotic twins]

The study presents conditions mostly described as co-existing with the keratoconus in 7 patients (from among 300 examined) born from an uni-ovular twin pregnancy. Only one pair of twins showed keratoconus of both eyes and developing identically in both eyes.     

Idiopathic retinal holes in monozygotic twins

It remains controversial whether there is a significant genetic contribution to the pathogenesis of idiopathic giant retinal tears or retinal dialysis. In contrast, the underlying molecular genetic basis of several inherited vitreoretinal dystrophies is now well established, with also an increasing recognition of genetic factors in the development of myopia. We describe asymptomatic female monozygotic twins who were identified as having identical retinal holes. These cases represent the first evidence to our knowledge of a potential role of inherited factors in the causation of idiopathic peripheral retinal holes. This observation raises the need to examine the twin of any patient presenting with a retinal break(s).     

Round and Oval Cones in Keratoconus

In advanced keratoconus, there are two cone types. The more common round or nipple shaped cone is limited in diameter but may reach any degree of conicity. The cone center lies mostly in the lower nasal quadrant. The oval or sagging cone, is often larger and lies more commonly in the inferotemporal quadrant close to the periphery. The oval cone is usually associated with more episodes of corneal hydrops, scarring and difficulty in fitting contact lenses. Histopathologic review of 23 cases (10 round, 13 oval), revealed that the oval group had more breaks in Bowman's membrane, 10.1 versus 5.0, (P < 0.01), and a tendency toward greater pannus formation with more ruptures in Descemet's membrane. We hope this clinicopathologic correlation may allow a more logical approach to patient care based on recognizing two different cone types in advanced keratoconus.     

Two cases of mirror-image eye anomalies in monozygotic twins

We report two cases of mirror image anomalies in two different pairs of monozygotic twins. In case 1, the twins exhibited mirroring of strabismus and refractive errors. Twin 1 had 35 prism diopters (PD) right intermittent exotropia at distant fixation and myopic anisometropia that was spherical 2.00 diopters more myopic in the right eye. Twin 2 had 35 PD left intermittent exotropia at distant fixation and her left eye was more myopic by - spherical 1.00 diopters. In case 2, the twins were diagnosed with infantile nystagmus with upbeat jerk. Twin 1 exhibited a habitual head turn of 30° to the left with dampening of her nystagmus in dextroversion. Twin 2 also exhibited abnormal head position, but in his case the habitual turn was 30° to the right. We believe that this is the first report describing mirror imaged intermittent exotropia with anisometropia and infantile nystagmus with opposite abnormal head positions in pairs of monozygotic twins.     

圆锥角膜的超微结构研究

目的 观察圆锥角膜的超微结构变化,拟发现圆锥角膜的特异性改变,为探讨其发病机制提供依据。方法 行穿透角膜移植术的圆锥角膜片２０例,分别用光镜和电镜观察其各层次的改变。结果 圆锥角膜上皮层、基质层变薄,基底膜及前弹力层局限性断裂或破坏;上皮基底细胞水肿,角膜细胞形态、结构改变,并似有异常吞噬现象;基质排列紊乱,板层间可见微粒状沉积物。结论 提示圆锥角膜的原发病变可能在角膜基质细胞。     

表层角膜镜片术治疗圆锥角膜

采用表层角膜镜片术联合前房穿刺，手术治疗18例21眼圆锥角膜患者，经术后3个月～1年8个月的随访，患者的视力、矫正视力明显提高，角膜屈光力显著降低，平均为45．83D。认为对确诊为圆锥角膜但尚无后弹力层破裂，或中央视区尚未形成瘢痕的患者，应早期行该术治疗，术后疗效确切，作用持久，稳定。     

圆锥角膜的病理观察

用光镜和透射电镜观察了８例（９只眼）圆锥角膜的组织病理学改变，均系施行穿透性角膜移植术的晚期病例。角膜各层均发生了病理变化。角膜上皮变薄、水肿，部分基底细胞呈杯状变，细胞核染色质凝集；前弹力膜破坏并上皮长入，浅层散在高密度物质沉积；基质层变薄前突，散在高密度纤维，后基质层有淀粉样蛋白沉淀；后弹力膜断裂或皱褶；内皮细胞变薄，空泡形成，胞膜破碎，核脱落。角膜上皮、基底膜、内皮可见铁沉积。     

A New Case of Keratoconus Associated with Williams-Beuren Syndrome

ABSTRACT

Background: Williams-Beuren syndrome is a multisystemic genetic disorder caused by a contiguous gene deletion at 7q11.23. Keratoconus is a complex disease and it is suspected to have a genetic origin, although the specific gene responsible for keratoconus has not been identified. Although there are several ocular features in Williams-Beuren syndrome, keratoconus is not regularly described as part of this syndrome.

Purpose: To report a new patient with keratoconus and Williams-Beuren syndrome.

Discussion: This is the third case of an association between Williams-Beuren syndrome and keratoconus. The authors believe that the Williams-Beuren syndrome chromosome region can be a possible target for further investigation as the genetic basis of keratoconus.     

Keratoconus in pre-teen children: Demographics and clinical profile

Purpose:To study the demographics and clinical profile of keratoconus (KC) presenting in pre-teen children in India.Methods:This was a retrospective case series conducted as a single-institutional study at a tertiary eye center in India. A total of 586 eyes from 294 KC patients (aged 12 years or less) without any active comorbid conditions of the eye were included in the study. Slit-lamp biomicroscopy was used to document the clinical signs of KC. Information on age; gender; reason for consultation; family history; history of allergy, atopy, and eye rubbing; manifest refraction; uncorrected and best-corrected distance visual acuity (UCVA and BCVA, respectively); clinical presentation; and contact lens usage were also analyzed, along with data on types of medical and surgical treatments for KC and their outcomes.Results:The mean age of this pediatric KC patient cohort was 9.3 ± 1.8 years, and there was a male (70%) preponderance. Baseline mean UCVA, BCVA, steep keratometry, and flat keratometry were 0.86 ± 0.58 logMAR, 0.44 ± 0.38 logMAR, 54.82 ± 8.4 D, and 48.21 ± 9.5 D, respectively. Progression, necessitating collagen crosslinking (CXL), was noted in 12.7% eyes. Post-CXL, visual and topographic parameters remained stable without any complications till 6 months posttreatment. However, in eyes that did not undergo CXL, significant progression over time (P < 0.001) was observed. A keratoplasty was required in 2.3% eyes.Conclusion:KC was present at an advanced stage in 25% of the pre-teens in our series, and therefore, it is an important diagnostic entity when a refractive error is diagnosed, even in very young children.     

圆锥角膜的免疫组织化学研究

目的：了解圆锥角膜基底膜免疫组化的变化,以发现圆锥角膜可能的特异性改变,为探讨其发病机制提供依据。方法：收集圆锥角膜在我院眼科行穿透性角膜移植术的角膜片,用链霉亲和素－生物素法（SP法）检测圆锥角膜、角膜白斑、正常角膜基底膜Ⅳ型胶原、Fn、Ln表达的异同,并进行统计学分析。结果：圆锥角膜基底膜Ⅳ型胶原,Fn染色较正常角膜显著升高,但与角膜白斑比较无显著性差异。结论：圆锥角膜基底膜的改变可能与创伤愈合有关。提示圆锥角膜原发病变可能在角膜基质细胞。眼科学报2000;17：65－67。     

Spectral characteristics of rapid off-response in congenital deuteranomaly in one of monozygotic female twins

The spectral sensitivity of the rapid off-response in the electroretinogram was studied in monozygotic female twins. One case was diagnosed as congenital deuteranomaly, and the other was normal. The log ratio of the sensitivity at 480 nm to the sensitivity at 620 nm (log S480/S620) was within the deutan range in the first case and within the normal range in the second. The two cases were determined to be different at the retinal receptor level by study of the rapid off-response. This result of the rapid off-response was consistent with the results of the psychophysical examinations.     

圆锥角膜患者双眼角膜生物力学性能的对称性

目的：应用超高频Scheimpflug角膜生物力学分析仪（CorVis-ST）评估双眼圆锥角膜患者角膜生物力学性能的对称性。方法：病例系列研究。于2013 年12 月至2015 年7 月间根据Amsler-Krumeich圆锥角膜分期标准诊断纳入温州医科大学附属眼视光医院视光门诊就诊的双眼圆锥角膜患者40 例（80 眼）。每只受试眼均使用CorVis-ST测量3 次,得到10 项生物力学参数及眼内压（IOP）、中央角膜厚度（CCT）等12项参数。双眼间差异分析采用Student's t检验和Mann-Whitney U检验,双眼一致性分 析采用Bland-Altman方法。结果：12个CorVis-ST参数的双眼95%一致性界限分别为：第1次压平时间（AP1 T） -0.56 ~ 0.61 ms（Z=0.441,P =0.229）,第1次压平长度-0.75 ~ 0.77 mm（t =-0.178,P =0.907）,第1次压平速度-0.063 ~ 0.053 m/s（Z=-1.528,P =0.171）,第2次压平时间（AP2 T）-1.01 ~ 0.84 ms（t =-0.848, P =0.269）,第2 次压平长度-0.96 ~ 1.02 mm（t =-0.342,P =0.715）,第2 次压平速度-0.22 ~ 0.22 m/s（t =-0.087,P =0.812）,最大形变时间（T）-1.38 ~ 1.11 ms （Z =-1.170,P =0.162）,最大形变峰间距-1.70 ~ 3.93 mm（Z =-3.321,P =0.001）,最大形变曲率-2.30 ~ 2.74 mm（t =1.014,P =0.287）,最大形变幅度-0.34 ~ 0.28 mm（t =-1.057,P =0.221）,眼内压-3.61 ~ 3.91 mmHg（t =-1.152,P =0.267）,CCT-136 ~ 152 μm（t =-0.698,P =0.323）,双眼间差异除最大形变峰间距外均无统计学意义。对应的一致性比值分别为8.8%、45.0%、37.0%、4.6%、65.8%、50.0%、8.5%、78.8%、46.5%、29.1%、32.6%、32.3%。在12 个参数值中,AP1 T、AP2 T、T一致性比值较小,双眼间有着较高的一致性。结论：AP1 T、AP2 T、T拥有较高的双眼间对称性,在应用CorVis-ST对圆锥角膜患者行角膜生物力学性能研究时,应考虑到双眼间角膜生物力学对称性对结果的影响。     

Corneal Cross Linking for Keratoconus

Riboflavin-induced ultraviolet light (UV) cross linking has received a significant amount of attention in recent years. It is currently approved in Europe as a treatment for keratoconus and is also being used for other corneal disorders. The goal of this paper is to review in detail seminal papers and studies that have been done to support cross linking as a safe and effective treatment for patients with early stages of keratoconus.     

The Youngest Patient with Bilateral Keratoconus Secondary to Chronic Persistent Eye Rubbing

Abstract

We present the case of a four-year-old girl with bilateral keratoconus secondary to chronic persistent eye rubbing. She was referred to our clinic with intractable ocular itching and low vision. According to her family, she was generally rubbing her eyes. On slit-lamp biomicroscopic examination, bilateral papillary reactions were seen on the upper tarsal conjunctiva. Clinical examination and corneal topography were compatible with keratoconus. The patient's visual acuity was not evaluated because of cooperation difficulties. Systemic examination was normal. In fact, trauma may be the common underlying factor in eye rubbing and may cause development of keratoconus, even in the early years. To the best of our knowledge, this is the youngest patient with bilateral keratoconus secondary to chronic persistent eye rubbing in the literature. Keratoconus should be kept in mind in patients with severe ocular itching, even in small children.