Complications of foldable intraocular lenses requiring explantation or secondary intervention--2001 survey update

A survey of the complications associated with foldable intraocular lenses (IOLs) that required explantation or secondary intervention was sent to members of the American Society of Cataract and Refractive Surgery and the European Society of Cataract and Refractive Surgeons. Preoperative data about visual acuity, patient signs and symptoms, and complications requiring IOL removal were assessed. Postoperative results and outcomes were also analyzed. Complications and symptoms for each of the following major groups of foldable IOLs explanted were tabulated separately: 3-piece hydrophilic acrylic or hydrogel; 3-piece monofocal silicone; 3-piece hydrophobic acrylic; 1-piece hydrophobic acrylic with haptics; 3-piece multifocal silicone; 1-piece plate-type silicone. A total of 286 surveys were returned for evaluation. Intraocular lens calcification, incorrect lens power, optical visual aberrations, and decentration/dislocation were the most common reasons for removing a foldable IOL. Accurate IOL measurements, meticulous surgical technique, proper patient counseling, and careful manufacture of foldable IOL materials are the most important factors in avoiding complications with foldable IOLs.     

Complications of foldable intraocular lenses requiring explantation or secondary intervention--2003 survey update

The sixth annual survey of complications associated with foldable intraocular lenses (IOLs) requiring explantation or secondary intervention was sent to members of the American Society of Cataract and Refractive Surgery and the European Society of Cataract and Refractive Surgeons. Preoperative data about visual acuity, patient signs and symptoms, and complications requiring IOL removal were evaluated. Complications were then tabulated for each of the following major foldable IOL groups: 3-piece monofocal silicone, 3-piece hydrophobic acrylic, 1-piece hydrophobic acrylic with haptics, 3-piece hydrophilic acrylic (hydrogel), 1-piece hydrophilic acrylic (hydrogel), 1-piece plate-type silicone, 3-piece multifocal silicone, and Collamer. Two hundred seventy-three surveys were returned for evaluation. Dislocation/decentration, incorrect lens power, IOL calcification, and glare/optical aberrations were the most common reasons for removing foldable IOLs. Good surgical technique, accurate IOL power measurements, and high manufacturing standards for foldable IOL materials and designs are the most important factors in avoiding complications with foldable IOLs.     

Complications of foldable intraocular lenses requiring explantation or secondary intervention--2007 survey update

The tenth annual survey of complications associated with foldable intraocular lenses (IOLs) requiring explantation or secondary intervention was sent to members of the American Society of Cataract and Refractive Surgery and the European Society of Cataract and Refractive Surgeons. Preoperative data about visual acuity, patient signs and symptoms, and complications requiring IOL removal were evaluated. Complications were then tabulated for each of the following major foldable IOL groups: 1-piece (plate) silicone, 1-piece hydrophobic acrylic with haptics, 3-piece silicone, 3-piece hydrophobic acrylic, 3-piece hydrophilic acrylic (hydrogel), 3-piece unknown, multifocal acrylic, and multifocal silicone. One hundred forty-two surveys were returned for evaluation. Dislocation/decentration, incorrect IOL power, glare/optical aberrations, and IOL calcification were the most common reasons for removing foldable IOLs. Good surgical technique, accurate IOL power measurements, and high manufacturing standards for foldable IOL materials and designs are the most important factors in preventing complications.     

Complications with foldable intraocular lenses with subsequent explantation in 1998 and 1999. Results of a questionnaire evaluation

Purpose. A questionnaire was sent to all members of the German Society of Ophthalmic Surgeons to evaluate complications of foldable intraocular lenses (IOLs) that required explantation. Methods. Information on preoperative visual acuity, foldable IOL design and material as well as the reason for IOL explantation was obtained and analysed. We received 167 completed questionnaires for 1998 and 1999. Results. In 1998 and 1999 the most common reasons for IOL explantation were as follows: incorrect lens power for 56% of the 3-piece hydrophobic acrylic IOLs, 16% because of glare or other photic phenomena, 40% of the 1-piece hydrophilic acrylic IOLs were explanted because of incorrect lens power and 30% for IOL damage. For the 3-piece monofocal silicone IOLs, 41% were explanted because of incorrect IOL power and 32% because of IOL decentration. For the 1-piece Hydrogel IOL, 76% were explanted because of opacification of the optic and 14% because of incorrect lens power. Most multifocal IOLs were explanted because of photic phenomena. Conclusion. In addition to the most common complications such as decentration and incorrect IOL power observed in rigid IOLs, new complications associated with foldable IOLs occurred such as optic opacification, glare and photic phenomena. Some complications seemed to appear in particular IOL types (opacification: SC-60BOUV, MDR), while others were observed in all types of foldable lenses. Accurate calculation of the IOL power and further improvement of the IOL material and design seem to be necessary to minimise the rate of explantations.     

Complications of foldable intraocular lenses requiring explantation. Results of the 2000 and 2001 survey in Germany

PURPOSE. A survey was sent to all members of the German Society of Ophthalmic Surgeons to evaluate complications that required explantation of foldable intraocular lenses (IOLs). METHODS. Data on preoperative visual acuity, foldable IOL design and material, and the reason for explantation were obtained and analysed. We received 185 surveys for 2000 and 2001. RESULTS. In 2000 and 2001, the most common reasons for IOL explantation were: incorrect lens power (31%) and dislocation (19%) in three-piece acrylic IOLs, incorrect power (31%) and decentration (17%) in monofocal silicone IOLs, and opacification (46%) in hydrophilic IOLs. The most common reasons for the exchange of monofocal IOLs were lens opacification in 2000 and incorrect IOL power in 2001. CONCLUSION. Besides the most frequent complications of decentration and incorrect power observed in rigid IOLs,new complications associated with foldable IOLs occurred (e.g., optic opacification and calcification). Accurate calculation of IOL power and further improvements in material and design are still necessary to minimize the rate of explantations.     

Complications of foldable intraocular lenses requiring explantation or secondary intervention--2000 survey update

A survey of the complications associated with foldable intraocular lenses (IOLs) that required explantation or secondary intervention was sent to members of the American Society of Cataract and Refractive Surgery and was also available to members of the European Society of Cataract and Refractive Surgeons. Preoperative data about visual acuity, patient signs and symptoms, and complications were assessed, and postoperative results and outcomes were analyzed. Complications and symptoms for each of the major groups of foldable IOLs explanted were tabulated separately: 3-piece monofocal silicone; 3-piece acrylic; 1-piece (plate-type) silicone; and multifocal silicone. A total of 259 surveys returned for evaluation. Accurate IOL power measurements as well as meticulous surgical technique, IOL loading and insertion, and proper patient counseling/selection remain the most important factors in avoiding complications with foldable IOLs.     

Piggyback implantation using the AMO array multifocal intraocular lens

Piggyback intraocular lens (IOL) implantation allows refractive correction in cases in which the IOL power requirement exceeds that of the available lenses. By combining a piggyback technique with the use of a multifocal IOL, one can obtain the optical advantages of both, achieving high-quality visual acuity for distance and near vision and reducing the optical aberrations of extremely high-powered single IOLs. We report 5 hyperopic patients (6 eyes) who had phacoemulsification and in-the-bag implantation of 2 foldable IOLs in the bag, a silicone multifocal IOL placed in front of a silicone monofocal IOL. Good results were obtained in near and distance uncorrected visual acuities, and patient satisfaction was excellent in all cases. However, in 2 cases, the anteriorly placed IOL was exchanged because of incorrect power calculation. Piggyback IOL implantation with a multifocal lens appears to be a safe, efficient procedure and a good refractive solution.     

Decentration and tilt: silicone multifocal versus acrylic soft intraocular lenses

PURPOSE: To compare differences in decentration and tilt between a silicone multifocal and an acrylic intraocular lens (IOL) by evaluating postoperative changes. SETTING: Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul, Korea. METHODS: Forty eyes of 20 patients with IOL implantation were randomized into 2 groups according to IOL type: 3-piece silicone multifocal IOL or 3-piece acrylic IOL. All lenses were implanted in the capsular bag through a clear corneal incision after continuous curvilinear capsulorhexis and phacoemulsification. The amount of the decentration and the degree of the tilt of each IOL were measured using the EAS-1000 anterior eye segment analysis system 1 day and 1 and 2 months after surgery. RESULTS: No significant difference in decentration and tilt was found among the 3 follow-ups or between lens types. CONCLUSION: Neither IOL decentration nor tilt showed significant progression up to 2 months in eyes with a silicone multifocal or acrylic IOL when the IOLs were placed properly in the capsular bag. The amount of decentration and tilt was similar between lens types.     

Incision width after phacoemulsification with foldable intraocular lens implantation

PURPOSE: To determine the incision size after insertion of foldable intraocular lenses (IOLs) using both a forceps and injectors. SETTING: Intermountain Ocular Research Center, Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: One hundred patients had phacoemulsification through a clear corneal wound. The incision width was measured before and after IOL implantation. A 3-piece silicone IOL and a 3-piece acrylic IOL (both with an optic diameter of 5.5 mm) were inserted using a forceps. A plate-haptic silicone lens and a 3-piece silicone lens with a 6.0 mm diameter optic were inserted using an injector. RESULTS: The wound size in the group with the 3-piece silicone lens inserted with a forceps enlarged 4.4% (3.23 to 3.38 mm) in the low-power IOL group (15.0 to 20.0 diopters [D]) and 6.2% (3.24 to 3.44 mm) in the high-power IOL group (20.5 to 25.0 D). Similarly, the acrylic IOL wound enlarged 5% (3.21 to 3.37 mm) in the low-power IOL group and 6% (3.25 to 3.44 mm) in the high-power IOL group when a forceps was used. The 3-piece silicone and plate silicone lenses inserted using an injector enlarged the wound 3.2% and 3.3% (3.02 to 3.11 mm and 3.05 to 3.15 mm), respectively. There was no difference in the wound size with higher IOL powers in eyes with injected lenses. CONCLUSIONS: Clear corneal incisions enlarge after insertion of foldable IOLs in a predictable manner, with a forceps-inserted IOL enlarging the wound diameter more than lenses inserted with an injector. The forceps-inserted lens group also showed a difference in wound size related to IOL power.     

Effect of heparin surface modification in reducing silicone oil adherence to various intraocular lenses.

PURPOSE: To evaluate surface properties of various intraocular lenses (IOLs), including a newly fabricated heparin-surface-modified (HSM) silicone IOL, with special reference to their efficiency in reducing potential silicone oil adherence to the IOL optics. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Five groups of rigid and foldable IOLs were analyzed in an in vitro test for the percentage of silicone oil adherence: a single-piece foldable hydrophilic-acrylic IOL (n = 9); a single-piece rigid poly(methyl methacrylate) (PMMA) IOL with HSM coating of the lens optic (n = 9); a 3-piece foldable silicone optic IOL with HSM coating of the optic (n = 10); a single-piece standard rigid PMMA IOL (n = 7); and a standard 3-piece foldable silicone optic IOL (n = 9). After the IOLs were immersed in water and then in silicone oil, gross photographs taken. Image analysis was performed to evaluate the percentage of silicone oil coverage of the anterior and posterior surfaces of each IOL optic. RESULTS: The mean silicone oil coverage of the hydrophilic-acrylic IOLs was 5.6% +/- 2.5% (SD); of the HSM PMMA IOLs, 6.2% +/- 4.3%; of the HSM silicone optic IOLs, 6.7% +/- 3.2%; and of the standard PMMA IOLs, 20.3% +/- 13.3%. The mean silicone oil coverage was greatest on the standard silicone optic IOLs, 98.2% +/- 3.1%. CONCLUSIONS: Intraocular lenses with a hydrophilic optic have less tendency toward adherence to silicone oil than more hydrophobic designs. A foldable silicone IOL with heparin surface modification can significantly reduce potential silicone oil adherence, comparable to the level achievable with the rigid HSM PMMA designs. Two new foldable IOL styles, the HSM silicone IOL and IOLs in the general class of hydrophilic-acrylic, were highly efficacious in reducing silicone oil adherence. There is now a real choice of foldable lenses for patients with actual or potential vitreoretinal diseases.     

Scheimpflug measurement of intraocular lens position after piggyback implantation of foldable intraocular lenses in eyes with high hyperopia

PURPOSE: To investigate the position of 3-piece foldable intraocular lenses (IOLs) after piggyback implantation for high hyperopia. SETTING: University Eye Hospital, Johann Wolfgang Goethe University, Frankfurt am Main, Germany. METHODS: Eight eyes of 5 highly hyperopic patients had phacoemulsification and implantation of 2 foldable IOLs. In 3 eyes, both IOLs were implanted in the capsular bag. In 5 eyes, 1 IOL was placed in the capsular bag and the second IOL in the ciliary sulcus. Intraocular lens optic tilt and decentration, combined thickness of both IOLs, and anterior chamber depth (ACD) were measured postoperatively over a period of 18 months using Scheimpflug photography. RESULTS: All eyes with both IOLs in the capsular bag showed interpseudophakic opacification, with a mean increase in combined IOL thickness of 0.4 mm, a decrease in ACD of 0.3 mm, and a corresponding hyperopic shift of 4.00 diopters. Eyes in which the anterior IOL was placed in the ciliary sulcus showed no changes in refraction or combined IOL thickness. In these eyes, the anterior IOL had a higher mean decentration (0.49 mm +/- 0.20 [SD] after 12 months) than the posterior IOL (0.21 +/- 0.13 mm after 12 months). CONCLUSIONS: Piggyback IOL implantation with placement of 2 foldable IOLs in the capsular bag can be followed by a hyperopic shift that may be caused in part by displacement of the IOLs. Placement of the anterior IOL in the ciliary sulcus can lead to higher decentration of this IOL.     

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.     

Tilt and decentration of three-piece foldable high-refractive silicone and hydrophobic acrylic intraocular lenses with 6-mm optics in an intraindividual comparison

PURPOSE: Intraindividual comparison of tilt and decentration of three-piece foldable intraocular lenses (IOLs) with 6-mm optics and different edge design and material. DESIGN: Prospective randomized study. METHODS: Twenty-five patients with senile cataract (group I) received a foldable silicone, sharp optic edge IOL in one eye and a silicone, rounded optic edge IOL in the other eye. Group II (n = 28) received the foldable silicone, sharp optic edge IOL in one eye and an acrylate, sharp optic edge IOL in the other eye. Scheimpflug photography was performed after the procedure with an anterior eye segment analysis system. Tilt and decentration of the IOL optic were measured 1 week, 6 months, and 12 months after the procedure. RESULTS: In group I, the foldable silicone, sharp optic edge IOL showed a mean optic tilt of 3.03 +/- 1.79 degrees and an optic decentration of 0.24 +/- 0.13 mm; the silicone, rounded optic edge IOL showed a tilt of 3.26 +/- 1.69 degrees and a decentration of 0.23 +/- 0.13 mm. In group II, the foldable silicone, sharp optic edge IOL showed an average tilt of 2.34 +/- 1.81 degrees and a decentration of 0.29 +/- 0.21 mm after 12 months; the acrylate, sharp optic edge IOL had a tilt of 2.32 +/- 1.41 degrees and a decentration of 0.24 +/- 0.10 mm. There were no significant differences in either group. CONCLUSION: The examined IOLs showed a stable position regarding tilt and decentration in the first 12 postoperative months, independent of material and edge design. Slight deviations from the optical axis might affect the outcome in aspheric or multifocal IOLs.     

Evaluation of giant-cell deposits on foldable intraocular lenses after combined cataract and glaucoma surgery

PURPOSE: To compare the incidence of inflammatory giant-cell deposits (IGCDs) on various foldable intraocular lenses (IOLs) after combined cataract and glaucoma surgery. SETTING: The Phillips Eye Institute, Minneapolis, Minnesota, USA. METHODS: In this prospective randomized clinical trial, 128 patients were randomized to receive a single-piece, first-generation silicone lens (n = 36); a 3-piece acrylic lens (n = 40); or 3-piece, second-generation silicone lens (n = 52). All patients had combined phacoemulsification and trabeculectomy with mitomycin-C by 1 surgeon using a standardized technique. Dilated biomicroscopy was used to identify and quantitate IGCDs on the surface of the IOLs using a 6-point grading scale. RESULTS: Inflammatory giant-cell deposits were identified on 21 of 128 IOLs. Lens design was the most significant risk factor for deposit formation (P =.004). Inflammatory giant-cell deposits were most common in the first-generation silicone plate lens group (33%), less common in the acrylic lens group (15%), and least common in the 3-piece, second-generation silicone group (5.8%). Density of the deposits was significantly greater on the plate lens than the acrylic or the 3-piece silicone lenses (P <.0001). Although IOL design was the most significant risk factor for IGCD formation, other significant risk factors included intraoperative pupil stretch (P =.02) and preoperative miotic use (P =.04). CONCLUSION: Inflammatory giant-cell deposit formation was significantly greater on first-generation silicone plate IOLs than on acrylic or second-generation silicone IOLs. The deposits were somewhat more common on acrylic IOLs than on second-generation silicone IOLs. However, this difference was not clinically or statistically significant.     

Explantation of intraocular lenses

Cataract surgery has evolved recently along with the development of intraocular lenses. With this evolution of intraocular lenses from anterior chamber and iris-fixated lenses to more modern foldable posterior intraocular lenses has come an evolution in the complications that necessitate removal of the intraocular lens. Early generations of anterior chamber and iris-fixated intraocular lenses often had severe complications associated with them, such as pseudophakic bullous keratopathy, uveitis-glaucoma-hyphema syndrome, and chronic cystoid macular edema. With modern foldable intraocular lenses, decentration-dislocation and incorrect lens power, and glare and optical aberrations are leading indications for explantation. Some complications appear to be unique to particular styles of modern intraocular lenses, with incidence of glare and optical aberrations increasing, especially in acrylic and multifocal intraocular lenses. The clinical outcomes after an intraocular lens explantation or exchange have also improved markedly with the advent of modern foldable intraocular lenses. Postoperative visual acuity results are dependent on the preoperative complications associated with the explanted intraocular lens. Final visual results after exchange of modern foldable intraocular lenses have been uniformly good. This is probably because of fewer severe complications that lead to explantation of the intraocular lens.     

Rates and causes of intraoperative removal of foldable and rigid intraocular lenses: clinicopathological analysis of 100 cases

PURPOSE: To analyze the rates of and reasons for intraoperative explantation of foldable and rigid intraocular lenses (IOLs) to determine the complication profile of each IOL design. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: The study comprised data analysis of foldable (n = 85) and rigid (n = 15) IOL specimens that were explanted immediately after primary implantation. RESULTS: Eighty-five foldable intraoperative explants were accessioned. These comprised 14.5% of the 586 foldable IOL explants received between January 1988 and September 2000. There were 15 rigid poly(methyl methacrylate) (PMMA) intraoperative explants out of 2077 rigid explant specimens (0.7%). Fifty-one (60%) of the foldable IOLs requiring intraoperative explantation were the 1-piece silicone plate-haptic large-hole design, and 29 (34.1%) were the 3-piece silicone polyimide-haptic design. The most frequent reason for explantation of both designs was optic damage, 37.3% in the large-hole design and 55.2% in the polyimide design. Optic damage did not occur in rigid PMMA IOLs. CONCLUSION: Some foldable IOL designs have a higher risk of damage during surgical insertion than rigid designs. Two modern foldable IOLs, the silicone plate-haptic large-hole and the silicone polyimide-haptic, appear to be more prone to damage during folding, loading, and implantation than other IOLs.     

四种非球面人工晶状体植入术后倾斜和偏心的比较

目的 比较目前临床上常用的4种不同非球面人工晶状体(IOL)在囊袋内植入后偏心和倾斜的差异.方法 回顾性系列病例研究.回顾性分析单纯性白内障患者130只眼术行超声乳化白内障吸除联合IOL植入术后3个月的随访资料.患者分别植入一体四襻式亲水丙烯酸酯IOL(Akreos AO,美国Bausch & Lomb公司)、三体c形襻疏水丙烯酸酯IOL(Tecnis9003,美国AMO公司)、一体L形襻疏水丙烯酸酯IOL(SN60WF,Alcon)、一体C形襻亲水丙烯酸酯IOL(920H,Rayner)4种非球面IOL以及三体C形襻疏水丙烯酸酯球面IOL(AR40e,AMO).使用Pentacam三维眼前房测量系统采集各眼Scheimpflug图像,用Image-pro plus 6.0图像分析得出IOL的倾斜度和偏心量,满足正态分布和方差齐性的行单因素方差分析,采用SNK-q检验进行组间两两比较.结果 除AR40e组的IOL倾斜度之外,其余各组患者IOL偏心值和倾斜度在水平和垂直方向上的数值差异均无统计学意义,取倾斜或偏心的最大值作为该患者的最终结果.AO、Z9003、IQ、920H、AR40e各组患者IOL的平均倾斜度分别为2.08°、2.58°、1.72°、1.81°、3.22°,其差异有统计学意义(F=4.511,P=0.003);各组患者IOL的偏心量分别为0.04 mm、0.24 mm、0.25 mm、0.19 mm、0.18 mm,在垂直方向上其差异有统计学意义(F=4.162,P=0.047),而在水平方向上各组患者IOL偏心值差异则无统计学意义(F=3.921,P=0.056).Z9003组IOL的偏心量和倾斜度线性相关(r=-0.517,P=0.034).结论 不同非球面IOL囊袋内植入后无论倾斜和偏心,结果推断可能一体优于三体IOL,多襻支撑优于双襻支撑IOL,但仍需结合临床专业知识判断.     

Silicone and poly(methyl methacrylate) lens decentration associated with asymmetric capsule shrinkage in rabbits.

PURPOSE: To determine whether silicone intraocular lenses (IOLs) are readily affected by capsule shrinkage. SETTING: Department of Ophthalmology, Wakayama Medical College, Wakayama, Japan. METHODS: A D-shaped incision was made in the anterior capsule of 38 eyes of 20 white rabbits. One of 2 IOL types was implanted in the capsular bag: 3-piece silicone or single-piece all-poly(methyl methacrylate) (PMMA). Twenty-eight eyes were evaluated for IOL rotation and optic decentration. RESULTS: The extent of postoperative decentration and rotation observed with the silicone IOLs did not significantly exceed that of the PMMA IOLs. CONCLUSIONS: Our results, coupled with the advantages of small incision surgery, indicate that a silicone IOL is an effective choice.     

折叠式人工晶状体囊袋内植入后偏心与倾斜的临床研究

目的 比较目前临床上常用的四种折叠式人工晶状体（intraocular lens,IOL）在囊袋内植入后偏心与倾斜的差异。方法对65例／眼单纯性白内障患者进行术后3个月的随访。这些患者分别植入了一体式疏水丙烯酸酯IOL（SA60AT,Alcon）、三体式疏水丙烯酸酯IOL（AR40e，AMO）、三点固定式亲水丙烯酸酯IOL（XISTABI，IOLTECH）及四点固定式亲水丙烯酸酯IOL（QUATTRO SE，Comeal）。用眼前节成像系统Pentacam（Oculus）采集各眼的Scheimpflug图像，用图像分析的方法得出IOL的偏心值与倾斜度。结果SA60AT、AR40e、XLSTABI、QUATTRO SE四组患者IOL的平均偏心值分别为（281．49±169．58）μm、（346．35±177．08）μm、（531．33±254．70）μm、（360．59±185．91）μm，其差异有显著统计学意义（P=0.0100）。四组患者IOL的倾斜度的中位数分别为0．98°（0．70°～1．73°）、1．33°（0．86°-1.83°）、1．50°（0．80°-2．68°）、1.38°（0.94°～2.37°），其差异无统计学意义（P=0．3885）。四组患者的最佳矫正视力和对比敏感度差异无统计学意义（P〉0．05）。结论四种IOL囊袋内植入后在倾斜度方面无差异，而在居中性方面，SA60AT优于XLSTABI，其他各种IOL间两两比较均无明显差异。     

Two year results: sharp versus rounded optic edges on silicone lenses

To evaluate the role of optic edge design of 2 silicone intraocular lenses (IOLs) in 2 year clinical results.Department of Ophthalmology, University of Vienna, Medical School, Allgemeines Krankenhaus, Austria.In this comparative clinical study, 50 eyes had phacoemulsification and implantation of a high-refractive 3-piece silicone IOL with sharp optic edges (CeeOn model 911F) (n = 25) or a 3-piece silicone lens with rounded optic edges (CeeOn model 920) (n = 25). Biomicroscopic findings, including those of specular microscopic examination of the anterior lens surface, were documented and the results analyzed.After 2 years, a significant between-group difference in posterior capsule opacification (PCO) but not in anterior capsule alterations was observed. Behind all CeeOn 911F sharp-edge IOLs, the capsule remained clear; in 2 of 23 capsules behind the CeeOn 920 rounded-edge, a neodymium: YAG laser capsulotomy had to be performed for dense central fibrotic PCO. Seven of 21 of the remaining eyes had first-degree central fibrotic PCO, 14 of 23 had peripheral mixed fibrotic and slender Elschnig pearl PCO, and 8 of 23 had second-degree peripheral PCO. Specular microscopic findings did not differ between the 2 groups. No severe IOL decentration occurred in any eye; 25% in the sharp-edge group and 40% in the rounded-edge group had minimal decentration.The silicone IOL with the sharp optic edge design was associated with significantly reduced PCO 2 years postoperatively.