晶状体全脱位的人工晶状体植入术

目的观察晶状体全脱位患者行人工晶状体植入的效果与并发症。方法毫针固定脱位晶状体并圈套娩出,显微剪剪除脱出玻璃体加睫状沟缝线固定人工晶状体。术后随访６～１３ｍｏ,平均８．２ｍｏ．结果观察７例７眼术后视力０．８者１眼,０．７者１眼,０．５者３眼,０．３者２眼。术中术后并发症少。结论晶状体全脱位患者经过人工晶状体植入术后,均获得满意视力。     

Intraocular lens power calculation for lens exchange

PURPOSE: To examine patients who had intraocular lens (IOL) exchange for large postoperative refractive errors and determine the factors that contributed to the error in IOL power calculation. SETTING: Thirteen affiliated hospitals in Japan. METHODS: This study comprised 34 cases that required IOL exchange because of large refractive errors after primary lens implantation. Patients with intraoperative complications were excluded from the study. The potential contribution of axial length, corneal refractive power, IOL manufacturer, and IOL fixation to errors in the predicted power was examined retrospectively. Axial length was calculated by the SRK/T and Holladay formulas using refraction after primary IOL implantation. RESULTS: There was no statistical difference between the corneal refractive power before and after cataract surgery. The axial lengths calculated using the SRK/T and Holladay formulas were longer than the ultrasonic axial lengths in 24 and 23 cases, respectively. Using IOLs from the same manufacturer for both primary implantation and exchange reduced the error in predicted refraction. CONCLUSION: Axial length and IOL manufacturer were important factors in predicting refraction power in eyes requiring IOL exchange.     

晶状体或人工晶体脱入玻璃体腔的手术处理

目的探讨晶体或人工晶体脱位入玻璃体腔的处理方法。方法钝挫伤后晶体脱位3眼,白内障手术中或术后晶体或人工晶体脱位11眼。均采用标准睫状体扁平部三切口闭合式玻璃体切除方式。术中注入全氟化碳液体0.4～4ml。经角膜缘取出人工晶体或晶体,或是直接玻璃体腔内粉碎晶体。再植入前房型人工晶体,或行后房型人工晶体睫状沟缝线固定。结果14眼均顺利取出或粉碎玻璃体腔内晶体或人工晶体。13眼(92.86%)术中植入人工晶体。术后视力明显提高12眼(85.71%)。结论对晶体或人工晶体全脱位进入玻璃体腔者,需争取早期采用玻璃体切除联合脱位晶体或人工晶体取出或粉碎手术,争取再植入人工晶体。     

外伤性晶状体不全脱位的超声乳化手术

目的　探讨晶状体不全脱位的超声乳化及人工晶状体植入的手术方法。方法　对 32例 36眼晶状体不全脱位根据脱位程度选择不同术式 :脱位 <1 2 0°者 ,环行撕囊超声乳化植入后房型IOL ;脱位 1 2 0°～ 2 70°者 ,晶状体囊缝合至睫状沟 1针 ,环行撕囊 ,超声乳化 ,植入后房型IOL ;脱位≥2 70°者 ,囊缝合至睫状沟 2针后环行撕囊及超声乳化 ,植入后房型IOL。结果　随访 3～ 1 8月 ,平均 8月。术后裸眼视力 <0 0 5者 2眼占5 56 % ;0 0 5～ 0 2 5者 7眼占 1 9 44% ;0 3～ 0 5者 1 2眼占 33 33 % ;0 6～1 0者 9眼占 2 5 0 0 % ;>1 0者 6眼占 1 6 67%。结论　晶状体不全脱位根据其程度采用Adank和Hennekes的方法将晶状体囊缝合至睫状沟以固定囊袋 ,再进行超声乳化 ,植入后房型IOL是一种安全有效的治疗方法     

Contact lens compliance amongst soft contact lens users

目的:从卫生和镜片、镜片盒及镜片护理液的更换来调查隐形眼镜配戴者的依从性.方法:以每天配戴镜片至少8h、持续配戴≥6mo的隐形眼镜配戴者为研究对象.采用半结构化、经过预先测试和验证的问卷调查表,在接受口头知情同意后评估软性隐形眼镜配戴者的依从性.每位受试者都接受访问,收集有关戴隐形眼镜使用历史的信息.年龄、性别、使用的镜片类型、配戴经验(a)、配戴时间和习惯、一天中持续使用镜片的时间和护理方法的细节都进行了记录.结果:共73名参与者的平均年龄为23.63±5.23y.观察到:依从性最高的项目为镜片清洁和消毒程序(98%);依从性最低的是隐形眼镜配件护理(81%).依从性较差的是:更换镜片盒(41%),检查并丢弃过期的护理液(22%)和未能进行后续随访(22%).镜片配戴的性别、配戴方式、配戴类型以及隐形眼镜使用年限依从性间无统计学差异.结论:这项研究结果证明总体上配戴者依从性良好.然而,在隐形眼镜盒和护理液等镜片配件的护理中,存在一定程度的不遵嘱执行.我们认为有必要考虑改善镜片护理操作依从性的方法.     

Patterns of lens care practices and lens product contamination in contact lens associated microbial keratitis

A prospective study of 24 contact lens patients with culture- or histopathology-proven microbial keratitis was performed between July and December 1987 to determine associated lens care practices and patterns of lens care product contamination. A questionnaire was used to document methods of lens care. Bacterial cultures were performed on all available contact lenses, lens cases, and solutions (including saline, disinfectant, daily cleaner and wetting agents), in addition to standard smears and cultures of the corneal ulcer. Failure to follow standard recommendations regarding contact lens care was widespread (21 of 24, 88%). In the majority of patients (20 of 24, 83%) bacterial contamination of the contact lens, case, and/or solutions was present. Almost two-thirds (15 of 24, 62%) of patients used solutions that were more than 3 months old. Cosmetic extended wear lens patients were most likely (7 of 8, 88%) to use solutions that were more than 3 months old and very likely (6 of 8, 85%) to have contaminated solutions. Efforts to improve lens care and decrease lens product contamination are necessary to prevent contact lens associated corneal ulcers.     

Intraocular lens calculation formulas for new intraocular lens implants

Several different formulas are available for preoperative calculation of the required implant power for a desired postoperative refraction. However, the application of both theoretical and statistically derived regression formulas to the new generation of soft intraocular lens implants poses several difficulties. In this paper the calculation of an A constant for a specific intraocular hydrogel lens implant, as well as the derivation of a universal theoretical formula, is described. The theoretical formula can be applied to other implant styles with various optical configurations and composed of different biomaterials. The SRK and theoretical formulas have been applied retrospectively to a series of patients receiving an intraocular hydrogel lens implant. A comparison shows that both perform satisfactorily in predicting the desired postoperative refraction.     

Contact lens material characteristics associated with hydrogel lens dehydration

Purpose: To determine the association between material dehydration and hydrogel contact lens material characteristics, including water content and ionicity. Methods: Water content and refractive index data were derived from automated refractometry measurements of worn hydrogel contact lenses of 318 participants in the Contact Lens and Dry Eye Study (CLADES). Dehydration was determined in two ways; as the difference between nominal and measured (1) water content and (2) refractive index. Multiple regression models were used to examine the relation between dehydration and material characteristics, controlling for tear osmolality. Results: The overall measured and nominal water content values were 52.58 ± 7.49% and 56.88 ± 7.81% respectively, while the measured and nominal refractive indices were 1.429 ± 0.015 and 1.410 ± 0.017. High water content and ionic hydrogel lens materials were associated with greater dehydration (p < 0.0001 for both) than low water content and non‐ionic materials. When dehydration was assessed as the difference in refractive index, only high water content was associated with dehydration (p < 0.0001). Conclusions: High water content and ionic characteristics of hydrogel lens materials are associated with hydrogel lens dehydration, with the former being more strongly associated. Such dehydration changes could in turn lead to important clinical ramifications such as reduced oxygen transmissibility, greater lens adherence and reduced tear exchange.     

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.     

Clear lens extraction with intraocular lens implantation for hyperopia

PURPOSE: To analyze the results of clear lens extraction (CLE) with posterior chamber intraocular lens (IOL) implantation to correct hyperopia. SETTING: Eye Research Center and Dr. Agarwal's Eye Hospital, Chennai, India. METHODS: This prospective study comprised 20 hyperopic eyes of 12 patients between 19 and 50 years who had CLE with posterior chamber IOL implantation. Five patients had peripheral iridectomy during CLE as the angles were occludable. RESULTS: The mean hyperopic spherical equivalent refraction was +6.66 diopters (D) +/- 2.17 (SD) (range +4.75 to +13.00 D). The IOL power was calculated using the Holladay 2 formula. The mean follow-up was 16.96 months (range 6 to 35 months).The mean postoperative uncorrected visual acuity was 0.45 +/- 0.25 (range 0.10 to 1.00), a mean improvement of 3 Snellen lines from preoperatively. The mean postoperative best corrected visual acuity (BCVA) was 0.63 +/- 0.30, a mean improvement of 1 Snellen line. Three patients gained 2 lines of BCVA and 2 patients, 1 line. One patient lost 1 line of BCVA. Seventy percent of patients were within +/-0.50 D of the intended refraction. CONCLUSION: The results indicate that CLE with posterior chamber IOL implantation is safe, predictable, and effective.     

Shape of lens epithelial cells after intraocular lens implantation

PURPOSE: To evaluate the morphological behavior of lens epithelial cells (LECs) after human cataract surgery with implantation of a poly(methyl methacrylate) (PMMA) or silicone intraocular lens (IOL). SETTING: Department of Ophthalmology, Fujita Health University, Banbuntane Hotokukai Hospital, Nagoya, Aichi, Japan. METHODS: Morphological observations of LECs in the patients with IOLs were made by light and transmission electron microscopy. The LECs were from 4 areas: (1) the region below the anterior capsule, touching the IOL; (2) the area between region 1 and the equatorial region; (3) the equatorial region; and (4) the central equatorial region and of the posterior capsule not touching the IOL. Case 1 had implantation of a single-piece IOL with a PMMA optic and haptics. Case 2 had a 3-piece IOL with a PMMA optic and polypropylene haptics. Case 3 had a 3-piece IOL with a silicone optic and polypropylene haptics. Areas 1 and 4 could not be observed in Case 2. RESULTS: The major difference between the patient with a PMMA IOL (Case 1) and the patient with a silicone IOL (Case 3) was that among the 4 areas observed, collagen fibers were present only in area 1 in Case 1 but in areas 2 or 3 as well in Case 3. CONCLUSIONS: Fibrous collagen fibers appeared in regions in which LECs adhered and there was capsule contact with the IOL optic. In addition fibrous collagen fibers appeared in more areas in the eye with the silicone IOL than in that with the PMMA IOL, perhaps because IOLs with silicone optics move slightly while in the capsular bag.     

Refractive lens exchange with an array multifocal intraocular lens

PURPOSE: To prospectively evaluate safety, efficacy, predictability, stability, complications, and patient satisfaction after refractive lens exchange (clear lens extraction) followed by posterior chamber implantation of a multifocal intraocular lens (IOL). METHODS: Fifty eyes of 25 patients (mean age 51 years, range 44 to 62 years) with preoperative spherical equivalent refraction between -15.50 and +5.75 D and cylinder between 0 and 1.50 D underwent bilateral implantation of a zonal progressive multifocal IOL (Array, AMO). RESULTS: Eyes were divided into group A (n=24; myopia, average preoperative spherical equivalent refraction -7.11 +/- 3.25 D (-1.75 to -15.50 D), and group B (n=26; hyperopia, average preoperative spherical equivalent refraction +3.04 +/- 1.04 D). Follow-up was 6 months in all eyes. Postoperatively, all eyes of both groups were within +/-1.00 D of target refraction. No eye in group A and three eyes in group B sustained a loss of one line of BSCVA. Forty-seven eyes (94%) remained unchanged or gained one or more lines of their preoperative BSCVA. In all eyes, postoperative UCVA was 20/40 or better. When compared to preoperative, uncorrected near visual acuity improved (statistically significant). All patients achieved uncorrected binocular visual acuity of 20/30 and J4 or better. Patient satisfaction was extremely high; no intra- or postoperative complications were reported. CONCLUSION: Six-month results of implantation of the AMO Array multifocal IOL for refractive lens exchange demonstrated safety, efficacy, and predictability in correcting high ametropia and significant improvement of uncorrected near and distance visual acuity.     

Single lens to lens duplication: the missing link

Congenital anomalies of the lens include a wide range from lens coloboma to primary aphakia and doubling of lens. There have been few case reports of double lens; the etiology suggested is metaplastic changes in the surface ectoderm that leads to formation of two lens vesicles and hence resulting in double lens. We report a case with bilobed lens, which raises the possibility of explaining the etiology of double lens.