Acanthamoeba Keratitis

Acanthamoeba species are an important cause of microbial keratitis that may cause severe ocular inflammation and visual loss. The first cases were recognized in 1973, but the disease remained very rare until the 1980s, when an increase in incidence mainly associated with contact lens wear was reported. There is an increased risk when contact lens rinsing and soaking solutions are prepared with nonsterile water and salt tablets. The clinical picture is often characterized by severe pain with an early superficial keratitis that is often treated as herpes simplex infection. Subsequently a characteristic radial perineural infiltration may be seen, and ring infiltration is common. Limbitis and scleritis are frequent. Laboratory diagnosis is primarily by culture of epithelial samples inoculated onto agar plates spread with bacteria. Direct microscopy of samples using stains for the cyst wall or immunostaining may also be employed. A variety of topically applied therapeutic agents are thought to be effective, including propamidine isethionate, clotrimazole, polyhexamethylene biguanide, and chlorhexidine. Various combinations of these and other agents have been employed, often resulting in medical cure, especially if treatment is commenced early in the course of the disease. Penetrating keratoplasty is preferably avoided in inflamed eyes, but may be necessary in severe cases to preserve the globe or, when the infection has resolved, to restore corneal clarity for optical reasons. (Surv Ophthalmol 42:493–508, 1998.     

裂隙灯在隐形眼镜验配中的应用

探讨裂隙灯显微镜这一眼科常用设备，在隐形眼镜验配中的应用问题，介绍裂隙灯显微镜的结构，原理，使用方法，及其在隐形眼镜验配中的具体应用。     

肾上腺素及地塞米松对白内障患者晶状体上皮细胞增殖的影响

为了观察肾上腺素及地塞米松对白内障患者晶状体上皮细胞 (lensepithelialcell,LEC)增殖的影响并探讨其机制 ,在行白内障超声乳化术中 ,取出中央 5～ 7mm的晶状体前囊 ,将其均分成 3等份 ,用于对照组及两实验组 ,分别培养于 10 -6mol/L的肾上腺素及地塞米松 4 8h,免疫组织化学染色后 ,采用医用多功能图像分析系统测定增殖细胞核抗原 (proliferatingcellnuclearantigen ,PCNA)阳性面积率。结果显示 ,10 -6mol/L的肾上腺素及地塞米松对LEC的增殖有明显的抑制作用 ,PCNA的阳性面积率分别为 (2 6 14± 0 92 2 ) %和(3 338± 0 838) % ,与对照组比较 ,差异有显著性意义 (P <0 0 1)。研究表明 ,肾上腺素及地塞米松对白内障患者LEC有明显的抑制作用 ,从而可用于白内障术后防治后囊膜混浊的发生 ,为临床筛选防治后发性白内障的药物提供了科学依据。     

糖尿病患者白内障超声乳化摘除和人工晶体植入

目的：分析糖尿病患者白内障超声乳化摘除和人工晶体植入的效果及并发症。 方法对９７例（１２７眼）患有糖尿病的白内障术后患者的视力及并发症进行分析，并选取同年龄段、同性别、同时期、同一手术医生施行的非糖尿病白内障患者做对照。手术采用小切口隧道式超声乳化及爱袋内人工晶体植入法。随访期为３ｍｏ。 结果９７例患糖尿病的白内障术后病人视力达 ０． ５ 及以上 ８５． ８２％，达 ０． ３及以上 ８８． ９８％。术后常见并发症为角膜水肿、晶体前沉积物、晶体前膜和后囊混浊。未合并有眼底病变或合并单纯性糖尿病视网膜病变的糖尿病患者白内障与非糖尿病白内障术后视力及术中、术后并发症比较均无显著性差异。 结论糖尿病患者白内障摘除及人工晶体植入术后，大部分视力改善满意，术后并发症少。影响术后视力的主要原因是糖尿病视网膜病变合并黄斑病变。     

外伤性白内障后房型人工晶体植入术34例临床分析

目的 探讨外伤性白内障后房型人工晶体植入术的手术时机、手术方式及临床效果。方法 对34例(34眼)外伤性白内障进行回顾性分析。结果 术后3月裸眼视力0．05—0．25者11例，占32．3％，0.3-O.5者14饲，占41．2％，0．6—1．O者9例，占26．5％。结论 根据晶体外伤的情况选择手术时机和手术方式有利于改善患者术后视功能。     

Oculometry findings in high myopia at adult age: considerations based on oculometric follow‐up data over 28 years in a cohort‐based Danish high‐myopia series

Purpose: To present and discuss oculometry data in a series of adults with high myopia followed between the ages of 26 and 54 years. Emphasis is on axial length (AL) findings and corneal curvature radius (Crad). Methods: Thirty‐four out of the 39 individuals recruited as teenagers from a Copenhagen 1948 birth cohort with myopia of at least 6 D have had current follow‐up exams, to include AL measurements (by ultrasound, 1974–2002; the latter year also with the Zeiss IOLMaster) and keratometry. The cross‐sectional and longitudinal analyses are based primarily on the eyes with high myopia; however, the fellow eye is also assessed in unilateral cases. Results: At age 54 years, the maximum myopia in the series was ?26 D; the highest AL value was 35.4 mm. The myopia had increased in most, with an increase from the 26‐year oculometry baseline averaging 1.0 D [standard deviation (SD) 1.84]. Ultrasound measurements over the 28 years gave a significant correlation between axial eye elongation and myopia progression of adult age (r = 0.65). The regression line was y = 0.43 + 0.36x, with myopia increase on the x‐axis. Throughout sessions, the association between AL and refraction was given by correlation coefficients numerically above 0.8, whereas AL and Crad had r‐values of 0.3–0.5. However, a mean Crad in the sample of 7.66 (SD 0.28) mm meant that the more general expectancy of rather flat corneas in high myopia was not fulfilled. Our data further suggested a reduction in lens power over the study period. Conclusion: In relation to refraction, AL and Crad remain the two main oculometry parameters. Apparently the correlation patterns regarding the cornea that are broadly valid for axial ametropia in the population cannot be extended to the marginal high myopia tail of the distribution. A significant proportion of eyes with high myopia thus had steeper corneas than expected, as a so‐called index contribution (albeit a small one) to the marginal refractive error.     

近视眼发生发展及其光学干预

本文通过对近视眼发生发展、近视眼的流行病学研究、调节理论的回归、早发性近视与迟发性近视、持续的近距工作与近视、离焦的实验性研究等专题的文献综述,提出近视眼的发生、发展可能与多种因素有关。并对基于调节理论干预近视发展的各种尝试,结合临床实践谈了一些看法。尝试用棱镜改变注视方向,配合正球镜对近视进展患者加以控制。     

Sodium orthovanadate effect on outflow facility and intraocular pressure in live monkeys

Sodium orthovanadate (Na₃VO₄) is reported to reduce IOP by affecting aqueous formation, but whether it also affects outflow facility (OF) is unclear. We tested the effect of Na₃VO₄ on OF and intraocular pressure (IOP) in live cynomolgus monkeys, and on actin and cell adhesion organization in cultured human trabecular meshwork (HTM) cells. Total OF (n = 12) was measured by 2-level constant pressure perfusion of the monkey anterior chamber (AC) before and after exchange with 1 mM Na₃VO₄ or vehicle in opposite eyes. Topical 1% Na₃VO₄ or vehicle only was given twice daily (each 2 × 20 μL drops) for 4 days to opposite eyes (n = 8), and Goldmann IOP was measured before and hourly after treatment for 6 h on Days 1 and 4. Filamentous actin and vinculin-containing cell adhesions were examined by epifluorescence microscopy after the cells had been incubated with 1 mM Na₃VO₄ for 24 h. A) In monkeys, Na₃VO₄ increased OF by 29.3 ± 8.8% (mean ± s.e.m.) over the perfusion interval when adjusted for baseline and contralateral eye washout (p = 0.01; n = 12). B) Day 1 baseline IOP was 16.2 ± 1.5 mmHg in treated eyes and 15.9 ± 1.3 mmHg in the contralateral control eyes. Following treatment on Day 1, IOP was no different (p > 0.05) between treated eyes and control eyes at any time-point or compared to baseline. Day 4 mean IOP averaged over hours 2-6 was 13.5 ± 0.8 mmHg in treated eyes and 16.1 ± 0.2 mmHg in control eyes. Treated eye IOP was lower than its Day 4 baseline (p < 0.005), lower than control eyes for the same Day 4 interval (p = 0.009), and lower than the Day 1 baseline (p = 0.0000). Control eye IOP on Day 4 was not significantly different from baseline on Day 1. C) Incubation of HTM cells with 1 mM Na₃VO₄ for 24 h caused a loss of actin stress fibers and vinculin-containing adhesions. Cell retraction and separation was also observed in vanadate-treated cultures. Reformation of actin stress fibers, vinculin-containing adhesions and confluent monolayers occurred within 24 h after Na₃VO₄-containing culture medium was replaced with Na₃VO₄-free medium. Ocular administration of Na₃VO₄ to live monkeys significantly increases OF and reduces IOP. Na₃VO₄ reversibly disrupts actin and cell adhesion organization and causes retraction and separation of cultured HTM cells. Na₃VO₄ increases pressure-dependent outflow in live monkeys. Altered actin architecture in the TM may play a part in this increased OF.     

A review of the limitations of the first hydrogel contact lenses

Background: It is generally believed that the clinical performance of the original Czechoslovakian hydrogel contact lenses was poor but historical reviews provide very little explanation regarding their failings. There is a lack of information in the literature about their dimensions and, in particular, thickness, which is essential for the calculation of oxygen transmissibility. Until now no measurements on Czechoslovakian lenses have been reported. Methods: A literature search on Czechoslovakian lenses was made that spanned the first decade of their use and included peer‐reviewed journals, non‐refereed publications and a number of archived documents. In addition, the water content and dimensions of five Geltakt and four Spofa lenses were measured. Results: Lens packaging, lens lifetime, hygienic care, visual acuity, nominal lens dimensions, flexure, failure to correct astigmatism, corneal oedema, oxygen transmissibility, complications and wearing time are reviewed. Measurements on Czechoslovakian lenses indicate that the total diameter was similar to that of the cornea, the back optic zone radius was steep and the centre thickness was large. Conclusion: Problems associated with the Czechoslovakian lenses included packaging and an initial failure to require daily disinfection. Few complications of lens wear were reported, probably due to the comparatively small number of patients fitted and the limited wearing time that they achieved. Delayed disclosure of lens dimensions handicapped the development of a fitting technique. An acceptable visual acuity was attained in selected cases, while reduced acuity may sometimes have been due to uncorrected astigmatism or to poor lens quality. The most serious disadvantage was the very low oxygen transmissibility that could result in marked corneal oedema.