Generalized,severe epidermolysis bullosa simplex caused by a Keratin 5 p.E477K mutation

Epidermolysis bullosa simplex (EBS) is a skin fragility disorder resulting from mutations of structural proteins in the epidermis. We provide a brief report of long‐term survival and reproduction in a mother with EBS due to keratin 5 (KRT5) c.1429G > A (p.E477K) mutation, which causes a particularly severe form of the disease.     

Keratoconus in monozygotic twins in New Zealand

We report on a case of keratoconus in identical twins who were brought up in Christchurch, New Zealand. Videokeratoscopy using an EyeSys^a (EyeSys Laboratories, Houston, Texas, USA) revealed not only marked differences in severity of keratoconus between the sisters, but also non-equivalent cone types. Both twin sisters reported an exacerbation of their keratoconus during pregnancy and during breast feeding. Various factors affecting the development and progression of keratoconus are discussed. (Clin Exp Optom 1995; 78: 4: 125–129)     

Keratoconus,allergy, itch,eye‐rubbing and hand‐dominance

Background: One hypothesis for the pathogenesis of keratoconus includes teenage allergy, ocular itch and associated eye‐rubbing. Methods: This study examined the prevalence of these factors for teenage and adult patients. The results for a sample of 53 subjects with bilateral keratoconus were compared with those for a control sample of non‐keratoconus subjects, who also routinely wore RGP contact lenses. The strongest dominant hand and the eye with more advanced keratoconus were also determined, to examine for a relationship between them. Results: The keratoconic sample reported significantly higher levels of allergy, itch and rubbing as teenagers and as adults. However, all distributions were bimodal, consistent with the hypothesis that allergy, itch and rubbing are relevant in the pathogenesis of keratoconus only when the highest levels of these factors are present. For example, a significant relationship between the stronger dominant hand and the more advanced eye was evident only in subjects who reported the most severe rubbing. Conclusions: This finding adds weight to the circumstantial evidence that rubbing contributes to the pathogenesis of keratoconus. Low levels of teenage rubbing by some keratoconic subjects suggest a non‐rubbing pathogenesis and that emphasis on rubbing management is not warranted in these cases. However, high levels of adult rubbing reported by many keratoconic subjects indicate that the standard advice to avoid vigorous and prolonged rubbing is often not effective, even when repeated. There appears to be an indication for the need to improve the management of eye‐rubbing for some patients with keratoconus or at risk of developing this disease.     

Can true monocular keratoconus occur?

Evidence increasingly supports keratoconus as an inherited, genetic disorder. If this is the case, it would be expected to express itself as a binocular condition even though variable expression of the gene may show differing levels in the two eyes. It is a common occurrence in specialist contact lens practices to see pseudo‐monocular keratoconus, that is, an overt clinical level of the condition in one eye and forme fruste keratoconus in the other. The advent of videokeratoscopy has shown almost every case of apparent monocular keratoconus to be different expressions of the condition in the two eyes. Nevertheless, rare cases of the condition are seen that appear to be truly monocular. Such a case is presented in which the condition has been present for more than 23 years. The age of the subject makes the future onset of keratoconus highly unlikely and videokeratoscopy does not show the presence of forme fruste in the ‘good’ eye. There is no history of monocular eye rubbing. Pachymetry shows the normal eye to be well within the range of normal corneal thickness, while the keratoconus in the other eye is sufficiently advanced to warrant corneal grafting. Thus, it is a case of true monocular keratoconus and represents an extreme example of variable gene expression.     

准分子激光原位角膜磨削术后继发圆锥角膜病因分析

目的 对４眼准分子激光原位角膜磨削术（ＬＡＳＩＫ）后继发圆锥角膜进行病因分析。方法 为４眼重度近视患者行常规ＬＡＳＩＫ治疗,术后角膜地形图分析确诊圆锥角膜,对手术前皇检查的各项数值行回顾性分析。结果 ４眼ＬＡＳＩＫ术后患者激光切削后剩余角膜基质厚度均大于２００ｕｍ,眼压正常,术后７个月～１年半发生圆锥角膜,其中１眼行穿透性角膜移植术获得满意疗效。结论 虽然ＬＡＳＩＫ术后保留角膜常规厚度,眼压正常,     

稳定型圆锥角膜患者植入新型Phakic角膜接触镜的视觉效果分析

目的：评估可植入式Phakic角膜接触镜治疗稳定型圆锥角膜患者的疗效、安全性、稳定性和可预测性。

方法：共14例患者采用植入式Phakic角膜接触镜(IPCL)矫正屈光不正,测量了未矫正视力、最佳矫正视力、离焦曲线、对比敏感度、屈光度及可能的副作用。评估结果超过6mo。

结果：平均等效球镜度(SE)和散光在术后6mo末次检查时由术前-6.94±2.79 DS和-4.24±1.42 DC分别变为术后-0.23±0.43 DS和-1.05±0.49 DC。术前平均Snellen视力为0.18±0.10。6mo内未矫正视力和最佳矫正视力平均值分别为0.13±0.10和0.05±0.15。平均安全指数为1.11。所有眼视力均无降低,其中22眼视力提高超过1行。20眼(71.4%)屈光度在0.50 D以内,27眼(96.42%)在±1.00 D以内。术后1wk至6mo,屈光度变化为-0.23±0.43(范围： -1.00至+0.75)。6mo内角膜内皮细胞(ECL)丢失率小于5%。术后6mo眼压(IOP)为11.32±2.28 mmHg。

结论：Toric植入式Phakic角膜接触镜在矫正与稳定圆锥角膜相关的近视和近视散光方面具有有效性、安全性和可预测性。     

基于双通道技术的视觉质量分析系统在评估轻度圆锥角膜视觉质量中的应用

探讨视觉质量分析系统（OQAS）测量圆锥角膜眼与正常角膜眼之间视觉质量的差异。方法：横断面研究。选取正常角膜屈光不正患者32例（32眼）作为对照组,圆锥角膜患者27例（27眼）作为圆锥角膜组。采用OQAS测量每组在3、4、5 mm的人工瞳孔直径下的视觉质量参数调制传递函数截止频率（MTFcutoff）、Strehl比、不同对比度下的OQAS值（OV-100、OV-20、OV-9）,组间差异采用独立样本t检验或Mann-Whitney U检验,组内差异采用重复测量资料方差分析及Bonferroni校正。结果：圆锥角膜组在人工瞳孔分别为3、4、5 mm时的MTFcutoff、Strehl比、OV-100、OV-20、OV-9均低于对照组（3 mm：t=6.658、6.695、6.660、6.493、6.778;4 mm：t=7.106、6.567、7.109、6.802、6.788; 5 mm：t=6.148、7.254、6.158、6.446、7.210;P均<0.001）。对照组及圆锥角膜组内MTFcutoff、Strehl比、 OV-100、OV-20、OV-9 在不同人工瞳孔大小的组内比较差异有统计学意义（对照组：F=42.205、 28.335、42.559、32.621、30.372;圆锥角膜组：F=15.732、11.533、15.625、13.870、10.495;均 P<0.001）。结论：双通道OQAS测量结果表明圆锥角膜的视觉质量较正常眼明显下降,圆锥角膜及正常眼的视觉质量均随着瞳孔增大而下降。     

Polymorphism Analysis of VSX1 and SOD1 Genes in Greek Patients with Keratoconus

Background: A number of mutations in the VSX1 and SOD1 genes have been reported to be associated with keratoconus (KC), however the results from different studies are controversial. In this study, we conducted the genotyping of common polymorphisms [VSX1: D144E, H244R, R166W, G160D; SOD1: intronic 7-base deletion (c.169?+?50delTAAACAG)], in a case–control sample panel of the Greek population.

Materials and methods: A case–control panel, with 33 KC patients and 78 healthy controls, were surveyed. DNA from each individual was tested for the VSX1: D144E, H244R, R166W, G160D and SOD1: intronic 7-base deletion (c.169?+?50delTAAACAG) polymorphisms by direct sequencing.

Results: We observed no polymorphisms of the VSX1 gene in the case–control panel. Concerning the SOD1 intronic 7-base deletion (c.169?+?50delTAAACAG), our findings suggest that heterozygous carriers are over-represented among KC cases compared to healthy controls (p?=?0.002).

Conclusions: We cannot confirm the previously reported association of the polymorphism in the VSX1 gene with KC. Our results suggest a possible causative role of SOD1 in the pathogenesis of KC. Further studies are required to identify other important genetic factors involved in the pathogenesis and progression of KC.