Bacterial adhesion to rigid and foldable posterior chamber intraocular lenses: in vitro study

PURPOSE: To determine the in vitro bacterial adherence to intraocular lenses (IOLs) routinely used at 1 center. SETTING: University Hospital of Vienna, Vienna, Austria. METHODS: Four types of rigid IOLs (hydrophobic poly[methyl methacrylate] [PMMA] and hydrophilic heparin-surface-modified PMMA) and 5 types of foldable intraocular lenses (hydrophobic silicone, hydrophobic acrylic, and hydrophilic acrylic) were used in the experiment. Under standardized conditions, the IOLs were contaminated with 2 strains of Staphylococcus epidermidis. A sonication method and impression method were used for quantification. The mean bacterial density per lens type (colony forming units/mm(2)) was compared. RESULTS: With both germs and both quantification methods, more bacteria was found on hydrophobic lenses than on IOLs with hydrophilic surfaces (P =.001). The Alcon AcrySof and Askin UV80F IOLs had the greatest and the Corneal Acrygel and Bausch & Lomb Hydroview IOLs the least affinity to these microorganisms. CONCLUSION: The data suggest that hydrophilic IOLs can help reduce the rate of postoperative endophthalmitis as a result of their surface properties.     

两种矫正高度近视虹膜夹型人工晶状体植入后眼内稳定评价

目的 评估两种虹膜夹型有晶状体眼人工晶状体(ICPIOL)矫正超高度近视植入后的稳定性和安全性.方法 选取超高度近视患者8例16只眼,依据度数1只眼植入硬性型ICPIOL;另眼植入折叠型ICPIOL.术后随诊3月,使用Pentacam前房分析仪分别评估人工晶状体距离中心角膜和距离自然晶状体之间的距离;使用角膜内皮测量仪,分别测量术前术后角膜内皮细胞记数,以评估其安全性及眼内稳定性.结果 术后3个月裸眼视力6只眼(38%)≧1.0,10只眼(63%)≧0.5.最佳矫正视力7只眼(44%)≧1.0,16只眼(100%)≧0.5.术后15只眼最佳矫正视力均达到并超过术前最佳矫正视力,11只眼(69%)提高视力表两行.角膜内皮至IOL光学部前表面距离为(2.04±0.38)mm.IOL后表面与自然晶状体间的距离为(0.76±0.15)mm.两种ICPIOL相比各组数据差异无统计学意义(P＞0.05).结论 两种ICPIOL术后眼内稳定性好,但还应长期随诊观察.     

Optical resolution of foldable intraocular lenses

Recently manufactured intraocular lenses (IOLs) (STAAR AA 4203 made of silicone and IOGEL PC-12 made of polyHEMA) were tested before and after implantation simulation for axial optical resolution (model eye), for optical surface quality (photokeratoscope), and for surface microtrauma (scanning electron microscopy). At a 3 mm pupillary opening, both lens types achieved a mean axial resolution of 1.25 (range 1.0 to 1.5) on an optotype analogous resolution target. When the pupillary opening was increased to 6 mm, polymacon IOLs showed only a moderate resolution decrease (up to one line) and loss of contrast (up to 30%); silicone IOLs showed almost no decrease. Photokeratoscopic evaluation revealed that a circular optical nonhomogeneity at the peripheral optical zone of the hydrogel IOLs is the source of this impairment. Groove-like surface deformities occasionally observed by scanning electron microscopy did not detectably decrease resolution or contrast.     

Visual performance: Comparison of foldable intraocular lenses

PURPOSE: To compare best distance visual acuity, color perception, and contrast sensitivity between eyes with an AcrySof Natural intraocular lens (IOL) (Alcon Laboratories Inc.) and fellow eye with an AcrySof IOL and to compare results in the IOL groups to those in normal, similarly aged patients with clear phakic eyes. SETTING: Sri Sankaradeva Nethralaya, Guwahati, India. METHODS: This prospective randomized parallel group single-center patient-masked examiner-masked study comprised 26 eyes of 13 healthy patients with bilateral age-related cataract. All patients had cataract surgery by phacoemulsification in both eyes; 1 eye received an AcrySof Natural IOL (SN60AT) and the fellow eye, an AcrySof (SA60AT) IOL. Final postoperative examination was performed at the end of 18 months. In addition to other findings, visual acuity, color perception, and contrast sensitivity were recorded. A group of normal, similarly aged phakic individuals with clear lenses was examined for contrast sensitivity. The records thus obtained were analyzed statistically. RESULTS: The AcrySof and AcrySof Natural IOL groups had a statistically significant improvement in visual acuity and color perception in comparison to preoperative status, and this was maintained until the last postoperative follow-up at 18 months. There was no statistically significant difference in the findings between the 2 IOL groups. The AcrySof and the AcrySof Natural IOL groups showed significant improvement in contrast sensitivity from the preoperative to the postoperative period (both P < .001). However, the AcrySof Natural IOL group was better than the AcrySof IOL group when each group was compared separately to similarly aged phakic individuals with clear lenses. CONCLUSIONS: Pseudophakia following AcrySof Natural SN60AT and AcrySof SA60AT IOL implantation led to equivalent visual acuity and color perception. But the contrast sensitivity in the AcrySof Natural group was better and near normal in reference to a healthy, age-matched control group.     

Transscleral fixation of foldable intraocular lenses

PURPOSE: To report the results of transscleral implantation of foldable intraocular lenses (IOLs). SETTING: Department of Ophthalmology Dokuz Eylül University School of Medicine, Izmir, Turkey. METHODS: Twenty eyes of 20 patients had transscleral fixation of a foldable IOL combined with conventional 3-port pars plana vitrectomy or anterior vitrectomy. Twelve eyes had lens luxation, 8 traumatic and 4 idiopathic. Six eyes were aphakic, 3 after extracapsular cataract extraction and 3 as a result of complicated phacoemulsification. One patient with a mature cataract and pseudoexfoliation had a wide zonular dialysis during phacoemulsification. One patient had an opacified hydrophilic acrylic IOL. RESULTS: The mean age of the patients was 52.9 years (range 17 to 80 years). The mean preoperative best corrected visual acuity (BCVA) was 20/63 (range counting fingers to 20/25). The mean preoperative refraction was +10.8 diopters (D) (range +10 to +13 D) and the mean preoperative astigmatism, 1.8 D (range 1.0 to 5.5 D). Sixteen IOLs were hydrophobic acrylic, 14 of which were 3-piece AcrySof MA60BM (Alcon) and 2 of which were Sensar AR40 (Allergan). Four IOLs, all VisaAcryl(Staar), were hydrophilic acrylic. The mean power of the IOLs was +22.0 D (range 19.0 to 26.0 D). The mean follow-up was 12 months (range 1 to 18 months). The postoperative BCVA ranged between 20/100 and 20/20, and the mean postoperative astigmatism was 1.1 D (range 0.5 to 4.0 D) at the last follow-up visit. The difference was statistically significant (P<.05). Suture exposure and cystoid macular edema were the only complications, each occurring in 2 eyes. CONCLUSION: Transscleral fixation of foldable IOLs takes less time and results in fewer complications and better visual outcomes.     

Management of dislocated foldable intraocular lenses

BACKGROUND: Foldable intraocular lenses (IOLs) have replaced rigid IOLs as the standard for cataract surgery. As with their predecessors, some foldable IOLs manifest dislocation. The applicability of techniques developed for dislocated rigid IOLs to dislocated foldable IOLs has not been widely studied. PURPOSE: The purpose of this study was to evaluate the results of management techniques for dislocated foldable IOLs. DESIGN: Retrospective, interventional case study. RESULTS: Thirty-two eyes underwent repair including repositioning without scleral sutures (17 eyes), repositioning using scleral suture (8), and IOL exchange (7). IOL types included silicone plate IOLs (15 eyes), 3-piece acrylic IOLs (12), and others (5). The visual acuity outcomes and complication rates were similar for all IOL types and surgical techniques. CONCLUSION: With minimal modifications and a few important exceptions, previously reported techniques for management of dislocated IOLs, including repositioning with or without scleral suture fixation, may be applied effectively to many styles of foldable IOLs.     

Position of rigid and foldable iris-fixated myopic phakic intraocular lenses evaluated by Scheimpflug photography

PURPOSE: To evaluate the postoperative intraocular positional stability of 1 rigid poly(methyl methacrylate) (PMMA) phakic intraocular lens (pIOL) model and 2 foldable polysilicone-PMMA iris-fixated pIOL models. SETTING: Department of Ophthalmology, Johann Wolfgang Goethe-University Frankfurt am Main, Germany. METHODS: One of 3 iris-fixated pIOL models (Artisan, Artiflex I, and Artiflex II, Ophtec BV) was implanted in 45 eyes of 26 patients with myopia or myopic astigmatism. The central distance between the pIOL and corneal endothelium and between the pIOL and anterior surface of the crystalline lens was evaluated using Scheimpflug photography 6 and 12 months after surgery. RESULTS: The mean preoperative spherical equivalent was -9.32 diopters +/- 1.78 (SD) (range -6.5 to -13.5 D). Each IOL model was implanted in 15 eyes. The median distance from the central corneal endothelium to the anterior surface of the pIOL at 6 months and 12 months was 2.65 mm and 2.64 mm, respectively, in the Artisan group, 2.47 mm and 2.50 mm, respectively, in the Artiflex I group, and 2.48 mm and 2.52 mm, respectively, in the Artiflex II group. The median distance between the posterior surface of the pIOL and the anterior surface of the crystalline lens at 6 months and 12 months was 0.40 mm and 0.48 mm, respectively, in the Artisan group, 0.53 mm and 0.55 mm, respectively, in the Artiflex I group, and 0.68 mm and 0.66 mm, respectively, in the Artiflex II group. At 12 months, the distance between the pIOL and crystalline lens was statistically significantly greater in the Artiflex II group than in the Artisan group (P<.01). CONCLUSION: The intraocular position of rigid pIOLs and foldable silicone iris-supported pIOLs showed a difference between the 3 pIOL models in space to the crystalline lens and the corneal endothelium, which may affect long-term results in terms of IOL interaction with surrounding tissue.     

Cost effectiveness of foldable multifocal intraocular lenses compared to foldable monofocal intraocular lenses for cataract surgery

AIM: To analyse the cost effectiveness of foldable monofocal intraocular lenses (IOLs) compared to foldable multifocal IOLs in cataract surgery alongside a prospective, multicentre randomised clinical trial (RCT). METHODS: Patients underwent cataract surgery with bilateral monofocal (n = 97) or multifocal (n = 93) IOL implantation. Cost data and patient preferences, using the visual analogue scale (VAS), the time trade-off (TTO), and the standard gamble (SG) technique were obtained preoperatively and postoperatively by structured interviews. The incremental costs (multifocal minus monofocal), mean costs per patient, and differences in preferences were computed. RESULTS: Mean costs for glasses per patient in the monofocal group were 41.67 and in the multifocal group 149.58. The difference in costs between the multifocal and monofocal group was -92.09 and was statistically significant (p = 0.008). No significant differences were found in total costs or in effectiveness between the monofocal and multifocal IOL group. CONCLUSION: The cost effectiveness of multifocal IOLs is reduced to a cost minimisation analysis, because of the inability to demonstrate significant differences in effects. The use of multifocal IOLs in cataract surgery resulted in a significant reduction in costs for patient's postoperative spectacles.     

Treatment of keratoconus by toric foldable intraocular lenses

PURPOSE: To report on the correction of marked regular corneal astigmatism due to keratoconus by toric intraocular lenses (IOL). SETTING: University eye hospital. METHODS: A 66-year-old woman presented with cataract and unilateral keratoconus (keratometric readings: 50.2/41.3 diopters [D]). She underwent routine cataract surgery with implantation of a foldable posterior chamber toric IOL (refractive power: +10.0 D sphere/+12.0 D cylinder). A 68-year-old surgically aphakic woman presented with peripheral accentuated keratoconus with regular and stable corneal astigmatism (keratometric readings: 39.75/61.5 D). She underwent secondary implantation of a foldable toric IOL (refractive power: -9.0 D sphere/+30.0 D cylinder) into the ciliary sulcus. RESULTS: After a follow-up period of 4 months, visual acuity increased to 0.70 with a correction of +0.75 sphere -2.5 cylinder/84 degrees in Patient 1; after a follow-up period of 6 months, visual acuity increased to 0.60 with a correction of +1.0 -2.0/90 degrees in Patient 2. CONCLUSIONS: Foldable toric silicone IOL may be a surgical option in the management of regular marked corneal astigmatism caused by keratoconus.     

Neodymium:YAG laser damage threshold of foldable intraocular lenses

PURPOSE: To determine the energy level of the neodymium:YAG (Nd:YAG) laser that induced a 50% incidence of intraocular lens (IOL) damage in 5 foldable IOL materials. SETTING: Department of Ophthalmology, Siriraj Hospital Mahidol University, Bangkok, Thailand. METHODS: To simulate the condition within the capsular bag, an IOL was sandwiched between 2 rubber membranes. The front membrane had a central opening mimicking the anterior capsulotomy; the back membrane acted as the posterior capsule. The model was submerged in a water-filled chamber. The Nd:YAG laser with an automatic focus 150 microm beyond the focus of the aiming beam was used to perform a posterior capsulotomy. Three IOLs of each of 5 foldable IOL materials were tested. One type of poly(methyl methacrylate) (PMMA) was studied as a reference. The incidence of IOL damage at various energy levels was recorded. Linear regression analysis was used to determine the 50% incidence damage threshold. RESULTS: The 6 materials tested included 1 silicone lens (SI-40NB, AMO), 1 hydrophobic acrylic lens (MA60BM, Alcon), 3 hydrophilic acrylic lenses (Haptibag Ang, IOLtech; ACR6D, Corneal; H60M, Bausch & Lomb), and 1 PMMA lens (LX10BD, Alcon). The 50% incidence damage threshold values were 0.37 mJ, 0.54 mJ, 0.58 mJ, 0.52 mJ, 0.66 mJ, and 0.68 mJ, respectively. CONCLUSIONS: The 50% incidence damage threshold in all the IOLs was below the energy level normally used to perform a posterior capsulotomy in clinical practice. However, setting the laser at the lowest possible energy, focusing the laser beam beyond the posterior capsule, and performing the capsulotomy early should minimize the risk of IOL damage.     

经巩膜缝线固定折叠式人工晶状体的临床观察

目的探讨经巩膜缝线固定折叠式人工晶状体的临床应用价值。方法回顾性分析16例(16眼)无后囊支撑的无晶状体眼,经巩膜固定折叠式人工晶状体治疗的情况。对手术方式、效果、并发症和防治措施等进行了分析。结果术后视力0.1~0.2者2例,0.3~0.6者12例,0.8者2例。术后3月,平均手术性散光度数为(0.71±0.65)D。所有病例无严重并发症发生。结论折叠式人工晶状体缝线固定术为无晶状体囊支持的患眼提供了一种可供选择的安全有效的手术方式。     

Evaluation of 3 modern single-piece foldable intraocular lenses: clinicopathological study of posterior capsule opacification in a rabbit model

PURPOSE: To assess the development of posterior capsule opacification (PCO) with 3 modern single-piece foldable intraocular lenses (IOLs) in a histopathological study and to compare the potential preventive effects of the IOL design and biomaterial in retarding PCO. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Thirty-one rabbit eyes were randomly operated on with phacoemulsification and implantation of 3 single-piece foldable lenses: a hydrophilic acrylic design, the Rayner Centerflex 570H (n = 11); a hydrophobic acrylic design, the Alcon AcrySof SA30AL (n = 10); and a silicone large-hole plate design, the Staar AA-4203VF (n = 10). Central PCO (CPCO), peripheral PCO (PPCO), and Soemmering's ring formation were evaluated 3 weeks after surgery using the Miyake-Apple posterior photographic technique. Histological sections of each globe were prepared to document capsular bag status and performance of IOL geometry. RESULTS: The acrylic IOLs (Centerflex and AcrySof) had lower CPCO and PPCO scores than the silicone plate IOL (P <.05). There was no significant difference in Soemmering's ring formation among the 3 models. Pathological evaluations revealed effective blockage of migrating lens epithelial cells (LECs) at the site of the truncated optic edge of the Centerflex and AcrySof IOLs, even in the presence of large amounts of retained/regenerative cortical material. CONCLUSIONS: The AcrySof IOL has a hydrophobic surface and the Centerflex a hydrophilic surface, but no correlation to these characteristics could be identified. The single-piece AcrySof optic geometry created a clear-cut barrier effect equal to that of its 3-piece predecessor. The anatomic profile of the Centerflex IOL shows the same characteristics. The optics of both acrylic lenses have square truncated edges that functionally block ingrowth of migrating LECs toward the central visual axis, leaving clear posterior capsules. The square optic edge was an appropriate geometric configuration to create a barrier effect. There was no effect of the biomaterial on PCO prevention.     

人工晶状体摘出原因分析

目的 分析13例人工晶状体摘出的原因,探讨减少这种手术并发症的方法.方法 人工晶状体摘出13例(13眼).对摘出人工晶状体的原因、摘出人工晶状体的类型以及手术方法进行了分析.结果 13例年龄8～64岁.原发病为外伤性白内障9例,年龄相关性白内障2例,先天性白内障1例,并发性白内障1例.人工晶状体摘出原因是人工晶状体脱位6例,人工晶状体移位6例,角膜内皮功能失代偿1例,继发性青光眼伴人工晶状体脱位1例.摘出的13枚人工晶状体有三片式硬晶状体6枚,单片式硬晶状体2枚,三片式折叠晶状体3枚,单片式折叠晶状体1枚和1枚前房型人工晶状体.8例在摘出人工晶状体后重新植入人工晶状体,5例未再植入.结论 对复杂类型白内障的恰当处理、对常规白内障术中后囊破裂等并发症的正确处理、对植入人工晶状体类型及植入方法的正确选择是避免人工晶状体摘出并发症的积极措施.     

Pseudophakic accommodation with 2 models of foldable intraocular lenses

PURPOSE: To evaluate the amplitude of pseudophakic accommodation of 2 foldable intraocular lenses (IOLs) by measuring the anterior chamber depth (ACD) shift during a 1-year follow-up. SETTING: Department of Ophthalmology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary. METHODS: This prospective study comprised 44 eyes of 44 cataract patients operated on with phacoemulsification and in-the-bag implantation of Akreos Disc (22 eyes) or AcrySof MA60BM (22 eyes) IOLs. The ACD was measured by A-scan during fixation at 30 cm and again after instillation of cyclopentolate 1%. The ACD shift was calculated by subtracting the ACD under cyclopentolate from the ACD during fixation at 30 cm. Follow-up measurements were performed 3, 6, and 12 months after surgery. Statistical analysis concerning the difference between the 2 groups was done by the Student unpaired t test. RESULTS: The ACD shift was greater in the AcrySof group than in the Akreos Disc group at all 3 follow-up examinations. The difference was highly significant between the 2 groups at 6 and 12 months (both P = .004). After the operation, the ACD shift increased continuously with time in both groups. The mean ACD shift reached 0.57 mm +/- 0.25 (SD) in the AcrySof group and 0.42 +/- 0.24 mm in the Akreos group at 12 months. CONCLUSIONS: The 3-piece AcrySof MA60BM IOL with 10-degree posterior angulation had a significantly higher capacity for pseudophakic accommodation than the 1-piece plate-haptic Akreos Disc IOL. The continuous increase in the ACD shift in the postoperative period may mean that patients learn to achieve better accommodation with an IOL as time goes on.     

Evaluation of foldable intraocular lenses in patients with uveitis

OBJECTIVE: To evaluate various foldable posterior chamber intraocular lenses (IOLs) after phacoemulsification in patients with uveitis. DESIGN: A prospective, noncomparative, interventional case series. PARTICIPANTS: Forty-nine consecutive patients (60 eyes) with various types of uveitis (anterior, n = 20; posterior, n = 1; panuveitis, n = 37, intermediate, n = 2). INTERVENTION: All patients underwent phacoemulsification with foldable posterior chamber IOL implantation. All eyes were free of active inflammation at the time of surgery. A variety of IOL biomaterials were implanted: acrylic (n = 30), silicone (n = 17), and hydrogel (n = 13). MAIN OUTCOME MEASURES: Detailed examination was performed by one masked observer. Several parameters were compared for each implant biomaterial, including level of best corrected Snellen visual acuity at final follow-up, presence of posterior synechiae, anterior capsular phimosis, posterior capsule opacification, and the degree of cellular deposits on the IOL optic. RESULTS: There were 26 males and 23 females, aged 9 to 83 years (mean, 48 years). Follow-up ranged from 1 to 33 months (mean, 17.03 months). At final follow-up, 56 eyes (93.3%) had an improvement in visual acuity compared with preoperative levels as follows: 34 eyes (56.6%) achieved an improvement of four or more Snellen lines, and 44 eyes (73.3%) achieved 20/30 or better. Giant cells, observed on the IOL optic in 19 eyes (31.7%), were most often seen on the acrylic biomaterial at the 1-month follow-up, although this was not found to be statistically significant. Scratch marks produced by the lens-introducing forceps were seen in 24 eyes (40.0%), mainly on the acrylic and hydrogel optics. Posterior capsule opacification (PCO) occurred in 49 eyes (81.7%), with only 5 eyes requiring laser capsulotomy. There was no association between PCO and the various lens biomaterials. Other causes for reduced visual acuity included glaucomatous optic neuropathy (n = 5) and cystoid macular edema (n = 8). CONCLUSIONS: The use of foldable IOLs in eyes with uveitis is safe, but the optimal biomaterial has yet to be found.