Blepharoptosis induced by prolonged hard contact lens wear.

PURPOSE: The authors attempt to establish a relation between hard contact lens wear and upper eyelid ptosis. METHODS: This study consists of two parts. In the first part, the authors compare the unilateral or bilateral ptosis that developed during hard contact lens wear in 17 patients with the involutional ptosis that developed in another group of 73 patients. In the second part, the authors compare both upper and lower eyelid position in 46 patients who had been wearing hard contact lenses for at least 10 years with the position of 50 matched controls who had never worn contact lenses. RESULTS: The ptosis that had developed in the 17 patients who wore hard contact lenses was clinically similar to that caused by involutional levator disinsertion. The second part of the study shows that the prolonged wearers of hard contact lenses had upper eyelids that were lower by approximately 0.5 mm when compared with control subjects. This difference is statistically significant. According to standard criteria, there were at least 10 ptotic eyelids in the contact lens group versus 1 in the control group. CONCLUSION: The study findings suggest that prolonged hard contact lens wear may induce a lower position of the upper eyelid and eventually lead to ptosis through levator disinsertion.     

Corneal epithelial alterations induced by disposable contact lens wear.

PURPOSE: To study the effect of disposable extended-wear soft contact lenses on the corneal epithelium. METHODS: Thirteen healthy patients (1 male, 12 females; average age, 26.3 +/- 7.6 years) with or without histories of previous contact lens use were recruited for this study. Specular microscopic pictures of the corneal epithelium and endothelium were taken with the help of a specular contact lens, before and after 3 months of contact lens use. The pictures were analyzed by means of a computer-assisted morphometric analysis system. RESULTS: The mean cell area and coefficient of variation (CV) of the mean cell area of the corneal epithelium before contact lens use were 639.4 +/- 84.0 microns 2 and 29.1 +/- 13.2, respectively. After lens wear, the mean cell area increased to 819.7 +/- 99.2 microns 2 (P less than 0.01), whereas the CV decreased to 20.0 +/- 6.1 (P less than 0.05). The corresponding values for the endothelium were 300.8 +/- 22.5 microns 2 and 36.4 +/- 7.3 before contact lens use, and remained at 322.3 +/- 27.8 microns 2 and 32.8 +/- 3.7 after contact lens use, respectively (P greater than 0.05). CONCLUSIONS: Based on the 3-month results, disposable extended-wear soft contact lenses caused similar enlargement of the mean cell area of the superficial corneal epithelium, as has been reported previously. It would appear that disposable lenses may cause the same metabolic and physiologic changes in the corneal epithelium as do conventional extended-wear soft contact lenses.     

Corneal endothelial polymegathism induced by PMMA contact lens wear

Central corneal endothelial photographs were taken for 15 persons who had worn polymethylmethacrylate (PMMA) contact lenses for 7-15 yr and for a nonwearing control group matched for age and sex. An individual cell area analysis was made from the cell tracings. Significant endothelial polymegathism was noted for each member of the contact lens wearing group. PMMA wearers showed an average coefficient of variation of 0.445 for central corneal endothelial cell area compared to 0.245 for nonwearers (81.6% increase in polymegathism). The average maximum/minimum cell size ratio was 8.06 for the PMMA wearers vs 3.42 for the nonwearing control group. The frequency distributions for the cell areas reveal that the contact lens wearer develops cells that are much smaller and larger than normal.     

Contact lens induced keratitis associated with contact lens wear

PURPOSE: To evaluate clinical characteristics, risk factors, management and outcome of contact lens induced keratitis (CLIK) associated with contact lens wear. METHODS: The study comprised all consecutive patients presenting with contact lens related presumed microbial keratitis during a 12-month period at our department. Detailed demographic data, type of contact lens, duration of lens wear, wearing schedule and lens hygiene were derived from a self-administered questionnaire. Severity of ulcer, corneal scrapings, treatment and final outcome were evaluated. RESULTS: 27 patients with CLIK, some of which may have been sterile peripheral infiltrates, due to contact lens wear were detected. In the majority of the cases patients had used disposable soft contact lenses (89%) and most of them had a daily wearing schedule (78%). 51.8% patients cleaned their lenses regularly. 6 (22%) applied no disinfection since their lenses were disposable on removal. In 3 of our cases with CLIK, penetrating keratoplasty had to be performed. CONCLUSION: Disposable contact lenses seem to have been a predisposing factor for contact lens induced keratitis also when used on a daily wear schedule. Insufficient contact lens care products and/or manufacturing characteristics may be responsible for CLIK, which is also observed in otherwise compliant contact lens users. In 3 of our patients with CLIK keratoplasty became necessary, indicating that contact lens induced keratitis may result in severe corneal complications.     

Changes in the contrast sensitivity function induced by contact lens wear.

Contrast sensitivity functions (i.e. minimum contrast required to resolve a sine wave grating as a function of spatial frequency) were determined for subjects when wearing normal spectacle corrections and when wearing either hard or soft contact lenses. Corections provides a more definitive evaluation of visual performance with contact lenses than do the conventional clinical procedures.     

Histopathology of blepharoptosis induced by prolonged hard contact lens wear

PURPOSE: To clarify histopathologically the structural features of blepharoptosis in prolonged hard contact lens wearers. DESIGN: Retrospective case-control study. METHODS: Biopsy specimens from identical sites at the levator aponeurosis and Mueller muscle from 15 long-term hard contact lens wearers were examined histopathologically (group 1). They comprised two men and 13 women with bilateral blepharoptosis ranging in age from 26 to 59 years (mean +/- SD, 44.4 +/- 10.70 years). The average length of hard contact lens wear was 25.4 years (range 12 to 40 years), and the average spherical equivalent refractive error was -9.100 diopters (range -2.825 to -20.375 diopters). We also examined specimens from 15 patients with involutional blepharoptosis who underwent levator resection; they comprised three men and 12 women ranging in age from 64 to 79 years (mean +/- SD, 72.3 +/- 4.38 years). RESULTS: All patients in group 1 manifested fibrosis and negligible fatty degeneration in Mueller muscle. In group 2, we detected mild fibrosis in Mueller muscle and fatty degeneration of the aponeurosis and Mueller muscle. CONCLUSIONS: Prolonged hard contact lens wear induces fibrosis in Mueller muscle and may result in contact lens-induced blepharoptosis.     

Physiologic changes of the cornea with contact lens wear.

PURPOSE: This article reviews the corneal changes resulting from the hypoxia that occurs during sleep and specifically during contact lens wear. METHODS: Discussion includes a literature review and observations regarding the changes to the corneal epithelium, stroma, and endothelium that take place during sleep and wearing of contact lenses made from different materials. RESULTS: Hypoxia and hypercapnia cause significant changes to the corneal epithelium, stroma, and endothelium. Some of these changes can also be seen following the sleep cycle. Epithelial changes include decreased metabolic rate, morphologic changes, microcysts, changes in junctional integrity, decreased corneal sensation, and pannus formation. Stromal changes include stromal edema, stromal acidosis, neovascularization, and changes in corneal shape and, ultimately, corneal thinning. Endothelial changes include bleb formation, polymegethism, changes in endothelial cell density, and possible changes in endothelial function. CONCLUSIONS: There are multiple and significant corneal changes resulting from hypoxia and hypercapnia. These changes vary with the specific lens style. The high-oxygen-permeable contact lenses recently introduced may overcome some of these problems.     

Prolonging contact lens wear and making contact lens wear safer

PURPOSE: To summarize the present status of safety and efficacy of contact lens wear. DESIGN: Literature review. METHODS: Ovid Medline searches were performed on records from 1966 through 2005 using keywords: keratitis, contact lens complications, extended-wear contact lenses, and silicone-hydrogel contact lenses. RESULTS: Patients desire comfort, clarity of vision, and prolonged contact lens wear when contact lenses are used to correct refractive error. Practitioners desire patient satisfaction but also require maintenance of the integrity of the eye and no complications that jeopardize vision or health of the eye. Improvements in the oxygen permeability of the contact lens materials, design of the contact lens and its surface, and solutions for the maintenance of the lens have reduced but not eliminated the risks of infection, inflammation, and conjunctival papillary reaction associated with contact lens wear. The lessons of past and recent history suggest that patient education and practitioner participation in the management of contact lens wear continue to be critical factors for patient satisfaction and safety in the extended wear of contact lenses. CONCLUSIONS: The availability of highly oxygen permeable contact lenses has increased the tolerance and safety of extended contact lens wear, but patient instruction and education in proper use and care of lenses is required and caution is advised.     

Corneal endothelial changes associated with contact lens wear

Contact lenses may induce short- and long-term corneal endothelial changes. The endothelial bleb response is a short-term, reversible change noted with contact lens wear. Long-term endothelial changes such as polymegethism (increased variation in cell size) and pleomorphism (a decrease in the frequency of hexagonal cells) have also been detected in polymethylmethacrylate, rigid gas permeable, and daily and extended wear soft contact lens patients. These morphometric changes have also been seen in myopes, aphakes, and corneal transplant recipients. Differences in endothelial morphometry between the central and mid-peripheral regions of the cornea have also been noted in hard lens wearers. The long-term significance of these findings is discussed.     

Ocular microbiota and polymorphonuclear leucocyte recruitment during overnight contact lens wear

Bacterial colonization of the ocular surface and contact lens (CL) and recruitment of polymorphonuclear leucocytes (PMN) during overnight CL wear was examined in I I asymptomatic wearers. The ocular surface was more frequently colonized than the CL with commensal bacteria (W0.05). Following sleep, more bacteria were recovered from the CL compared with daily use (P<0.05), and fewer PMN were recruited compared t o sleep without CL wear (Plt;0.05). Overnight CL wear may inhibit physiological PMN recruitment t o the cornea by preventing their access, by modifying the chemotactic signal o r by altering the activation state ofthe recruited cells.     

A comparative study of corneal endothelial changes induced by different durations of soft contact lens wear

Purpose: To analyze the effect on the morphologic characteristics of the corneal endothelium of the duration of soft contact lens wearing periods. Methods: Ninety soft contact lens wearers were divided into three groups: short-term users, for less than 5 years (n=60 eyes); intermediate-term users, from 6 years to 10 years (n=60); long-term users, for more than 10 years (n=60). Thirty non-contact lens wearers (60 eyes) were included as controls. All eyes were examined with a specular microscope. Analysis of covariance was used to detect any differences among the controls and the various soft contact lens subgroups. Results: There was a significant correlation between duration of soft contact lens use and morphologic changes of corneal endothelium. All soft contact lens subgroups had a significantly greater coefficient of variation in cell size than non-contact lens users . The proportion of hexagonal cells and the mean corneal endothelial cell density in those using soft contact lenses for more than 6 years were significantly lower than in the control group . Soft contact lens wear was significantly correlated with decreasing corneal endothelial cell densities with time. Conclusion: The coefficient of variation in cell size may be a sensitive indicator of early morphologic changes of the corneal endothelium. As the decrease in cell density among the contact lens subgroups was significantly associated with the duration of soft contact lens wearing periods, it will be useful to investigate endothelial cell density for evaluation of corneal endothelial function concerned with contact lens wearing. Received: 7 December 1999 Revised: 22 August 2000 Accepted: 14 September 2000     

Morphologic effects of contact lens wear on the corneal surface.

We used specular microscopy of the corneal epithelium to examine 29 eyes of 29 patients each wearing one of five different types of contact lenses. We compared these with 24 eyes of 24 age-matched control patients. We found patients with aphakic extended wear soft contact lenses had significantly larger cells (818 +/- 186 microns2) than all other groups; and they were significantly larger than their age-matched control group (573 +/- 174 microns2) (P less than .002). The epithelial cells of extended wear soft contact lens patients (609 +/- 97 microns2) and daily wear rigid gas permeable contact lens patients (613 +/- 103 microns2) were larger than their control group of normal young patients (513 +/- 53 microns2). The cells of daily wear soft contact lens patients (484 +/- 111 microns2) and hard contact lens patients (517 +/- 46 microns2), however, were not different from controls. This study demonstrates a statistically significant shift in mean cell area of corneal epithelial cells in patients wearing some types of contact lenses.     

圆锥角膜患者长期配戴硬性透气性角膜接触镜后眼表变化分析

目的： 分析圆锥角膜患者长期配戴硬性透气性角膜接触镜(RGPCL)后眼表相关参数的变化。

方法： 采用前瞻性病例研究。纳入2018-01/2022-01在我院眼视光学中心门诊确诊并验配RGPCL的原发性圆锥角膜患者113例213眼,根据圆锥角膜严重程度分为轻度圆锥角膜组42例80眼,中度圆锥角膜组54例102眼,重度圆锥角膜组17例31眼。采用Keratograph眼表综合分析仪观察三组患者戴镜前,戴镜后1 wk,1、3、6、12 mo的非侵入性泪膜破裂时间(NIBUT)、非侵入性泪河高度(NITMH)、眼红指数、脂质层厚度、角膜荧光染色、睑板腺分泌功能,Schirmer I试验及眼表疾病指数量表(OSDI)评分变化。

结果：三组患者戴镜前性别、年龄、NIBUT、NITMH、脂质层厚度、睑板腺分泌功能、Schirmer Ⅰ试验均无差异(P>0.05),而球镜、柱镜、等效球镜(SE)、BCVA、IOP_NCT、角膜前、后表面Kmax、最薄点角膜厚度、眼红指数、角膜荧光染色、OSDI评分均有差异(P<0.05)。低度圆锥角膜组NIBUT戴镜3、6、12 mo 较戴镜前有差异(P<0.05); NITMH戴镜6、12 mo较戴镜前有差异(P<0.05); 眼红指数、角膜荧光染色、OSDI戴镜1 wk,1 mo较戴镜前有差异(P<0.05); 脂质层厚度和睑板腺分泌功能戴镜12 mo较戴镜前有差异(P<0.05)。中度圆锥角膜组NIBUT戴镜6、12 mo较戴镜前有差异(P<0.05); NITMH、脂质层厚度、睑板腺分泌功能戴镜12 mo较戴镜前有差异(P<0.05); 眼红指数戴镜1 wk,1、3 mo较戴镜前有差异(P<0.05); 角膜荧光染色戴镜后1 wk较戴镜前有差异(P<0.05); OSDI评分戴镜1 wk,1 mo较戴镜前有差异(P<0.05)。高度圆锥角膜组NIBUT、NITMH、眼红指数戴镜1 wk,1、3、6、12 mo较戴镜前有差异(P<0.05); 脂质层厚度戴镜6、12 mo较戴镜前有差异(P<0.05); 角膜荧光染色和OSDI评分戴镜1 wk,6、12 mo较戴镜前有差异(P<0.05); 睑板腺分泌功能戴镜6、12 mo较戴镜前有差异(P<0.05); Schirmer Ⅰ试验戴镜12 mo较戴镜前有差异(P<0.05)。

结论： 圆锥角膜患者长期配戴RGPCL会不同程度影响眼表微循环,从而影响患者的主观舒适度,但对患者的视觉质量无明显影响,长期规范配戴RGPCL控制圆锥角膜进展具有良好的安全性。     

Microbial changes in the ocular environment with contact lens wear.

A group of 30 subjects, each fit with a single disposable or non-disposable soft contact lens, was further randomized to a daily wear or extended wear schedule to determine the effect of lens wear on the normal conjunctival flora. Cultures of the subjects' inferior cul-de-sacs were taken at baseline before any lens wear and after one week of lens wear. Additionally, each subjects' lens was removed in a sterile manner and cultured at the end of the one week wear period. In all subjects, the fellow eye was used as a control. There were no statistically significant differences with respect to bacterial culture results between experimental and control eyes. Also, there were no significant differences between the pre- and post-lens wear groups. And no significant differences were found when the larger groups were broken down into different wear schedules and lens types and compared. The results of this study suggest that the ocular flora is not markedly changed after one week of contact lens wear. Also raised is the question of whether an altered ocular flora is an etiologic factor in the development of infectious keratitis in contact lens wearers.     

Ocular surface changes induced by topical antiglaucoma monotherapy

PURPOSE: To investigate the expression of inflammatory markers HLA-DR in impression cytology specimens from patients receiving topical antiglaucoma monotherapy. METHODS: Impression cytology specimens were obtained from patients taking no topical medication (n = 13) and from primary open-angle glaucoma or ocular hypertensive patients taking one topical medication for at least 3 months (latanoprost n = 14; betaxolol n = 12; timolol n = 14). None of the patients had any signs of ocular surface inflammation as detected by slit-lamp examination, a normal Schirmer's test and tear breakup time. The expression of HLA-DR on epithelial cells and T lymphocytes was analysed by flow cytometry. RESULTS: A significant increase in HLA-DR on epithelial cells in patients on monotherapy was detected (latanoprost p < 0.05; betaxolol p < 0.01; timolol p < 0.01). Although the duration of treatment differed significantly between individual groups, there was no significant correlation between the length of monotherapy and the expression of inflammatory markers by epithelial cells and T lymphocytes. In the latanoprost group, the increased expression of HLA-DR was associated with a shorter duration of treatment. CONCLUSIONS: The flow-cytometric results indicate that administration of a single topical medication preserved with benzalkonium chloride, irrespective of type, for 3 months or more induced a significant degree of subclinical inflammation detected as increased expression of HLA-DR on conjunctival epithelial cells.