Optical coherence tomography of intraocular lens implants and their relationship to the posterior capsule: a pilot study comparing a hydrophobic acrylic to a plate-haptic silicone type

BACKGROUND: Optical coherence tomography (OCT) has been used to examine the anterior as well as the posterior segment and can be used to examine the intraocular lens (IOL) and their relationship to the posterior capsule in vivo. OBJECTIVES: To use OCT to examine two of the IOLs and some of the features related to the development of posterior capsular opacification (PCO). METHODS: This is a pilot study of a prospective (n = 12) and a retrospective (n = 14) series of patients who had uneventful phacoemulsification and IOL implantation of either hydrophobic acrylic (Acrysof; Alcon) or plate-haptic (PH) silicone (C11UB; Chiron, Bausch & Lomb) IOLs. The outcome of interest was the ability of OCT to clearly delineate the outline of the IOL optics and their appositional relationship to the posterior capsule. RESULTS: OCT showed that hydrophobic acrylic IOLs had a better defined outline than PH silicone IOLs. It also showed close apposition between hydrophobic acrylic optics and the mid-peripheral part of the posterior capsule and the absence thereof with PH silicone IOLs. CONCLUSIONS: Hydrophobic acrylic implants have better definition on the OCT scans than PH silicone and they develop close apposition to the posterior capsule. The latter feature is consistent with the 'no space, no cell, no PCO' concept and what is known about the effect of the implant material and design on the rate of PCO.     

白内障术后后囊膜混浊的量化分析(英文)

目的:评估白内障术后疏水性丙烯酸人工晶状体Sensar AR40e和硅胶人工晶状体的后囊膜混浊(PCO),并用能客观评估PCO的软件量化分析。方法:共选择98眼行标准的超声乳化白内障吸除术,人工晶状体囊袋内固定。所有眼随机植入Sensar AR40e或硅胶人工晶状体,但同一患者植入的人工晶状体必须不同。在第1～2a时后照法拍摄后囊膜图像,通过去除浦肯野反光、增强对比度、过滤后增强低密度的PCO等方法处理后用POCO软件分析对比。结果:术后1a疏水性丙烯酸人工晶状体PCO百分比为0.32±0.13,硅胶人工晶状体为0.39±0.17(P=0.37)。2a时疏水性丙烯酸人工晶状体PCO百分比为0.42±0.20,硅胶晶状体为0.34±0.18(P=0.50)。患者术后1,2a时疏水性丙烯酸人工晶状体PCO的严重级别分别是0.50±0.30和0.82±0.58,与硅胶人工晶状体的0.63±0.35和0.55±0.35相比,无统计学意义(P=0.52,P=0.69)。结论:POCO后囊膜混浊量化分析系统提供了客观而且可重复性强的量化PCO的方法,也是研究预防PCO技术的有力工具。     

Uveal and capsular biocompatibility of hydrophilic acrylic, hydrophobic acrylic, and silicone intraocular lenses.

PURPOSE: To evaluate the long-term response of 6 types of 3-piece intraocular lenses (IOLs) by assessing the cellular reaction on the anterior IOL surface, the behavior of posterior and anterior capsule fibrosis, and flare. SETTING: Department of Ophthalmology, Medical School, University of Vienna, Vienna, Austria. METHODS: One hundred eighty eyes were prospectively randomized to receive 1 of 6 IOLs: hydrophilic acrylic Hydroview (Bausch & Lomb) or MemoryLens (ORC); hydrophobic acrylic AcrySof MA60BM (Alcon) or AMO Sensar AR40 (Allergan); hydrophobic silicone CeeOn 920 or CeeOn 911A (Pharmacia). The patients had standardized cataract surgery, postoperative medication, and follow-up. One year after surgery, 155 eyes were assessed. The cellular reaction was evaluated by specular microscopy of the anterior IOL surface. Anterior and posterior capsule opacification (PCO) was assessed semiquantitatively by biomicroscopy. Flare was measured with a Kowa FC-1000 laser flare-cell meter. RESULTS: Regarding uveal biocompatibility, the hydrophobic acrylic IOLs showed the highest incidence of late foreign-body cell reaction (AcrySof, 30%; AR40, 17%) followed by the hydrophilic acrylic (MemoryLens, 8%; Hydroview, 4%) and silicone (CeeOn 920, 4%; CeeOn 911A, 0%) (P =.0044). In all cases, the cellular reaction was low grade and clinically insignificant. Regarding capsular biocompatibility, some eyes developed lens epithelial cell (LEC) outgrowth on the anterior IOL surface. The highest incidence was in the hydrophilic acrylic group (Hydroview, 85%; MemoryLens, 27%) followed by the hydrophobic acrylic (AcrySof, 4%; AR40, 3%). No silicone IOL had LECs on the anterior surface. The difference among IOL groups was significant (P =.0001). Anterior capsule opacification was more predominant in the hydrophobic IOL groups. Posterior capsule opacification of the central 3.0 mm area was lowest in the groups with a sharp-edged optic (CeeOn 911A, AcrySof) followed by the round-edged silicone (CeeOn 920), hydrophobic acrylic (AR40), and hydrophilic acrylic IOLs (P =.0001). There was a significant difference in flare between the AR40 lens and the Hydroview, MemoryLens, CeeOn 911A, and CeeOn 920 (P <.004). There was no statistically significant difference in the postoperative cell count at 1 year. The power calculation showed that the sample size was sufficient. CONCLUSIONS: The differences in cellular reaction, although clinically mild in normal eyes, indicate that there were more giant cells with hydrophobic acrylic IOLs and an increased tendency toward LEC outgrowth with hydrophilic lenses. The incidence of PCO was lowest in the hydrophobic IOL groups, especially in groups with a sharp-edged optic. Second-generation silicone IOLs with a sharp edge had good uveal and capsular biocompatibility 1 year after surgery.     

Posterior capsule opacification after implantation of a hydrophilic or a hydrophobic acrylic intraocular lens: one-year follow-up

PURPOSE: To evaluate the effect of hydrophilic and hydrophobic single-piece acrylic intraocular lenses (IOLs) on posterior capsule opacification (PCO) after cataract surgery. SETTING: St. Erik's Eye Hospital, Stockholm, Sweden. METHODS: In a prospective study, 120 patients having cataract surgery were randomized to implantation of a hydrophilic acrylic IOL (BL27, Bausch & Lomb) or a hydrophobic acrylic IOL (AcrySof SA60AT, Alcon). Surgery was performed according to a standardized protocol by 1 of 3 surgeons. Best corrected visual acuity, contrast sensitivity, glare, intraocular pressure, and flare were measured 1 week, 3 months, and 1 year after surgery. Posterior capsule opacification was assessed by digital retroillumination photography and analysis using POCOman software at 1 year. The rate of neodymium:YAG (Nd:YAG) capsulotomy for each IOL was also recorded. RESULTS: At 1 year, the hydrophilic acrylic IOL group had a significantly greater percentage area and severity of PCO than the hydrophobic acrylic IOL group (P<.001). Two patients in the hydrophilic acrylic IOL group and 4 in the hydrophobic acrylic IOL group had an Nd:YAG capsulotomy within the first year (P>.05). Contrast sensitivity was significantly better in the hydrophilic acrylic group at 3 months (P<.05); however, at 12 months no difference between the IOLs was observed. There was no significant difference in the other measured parameters. CONCLUSION: Patients with the hydrophilic acrylic BL27 IOL had a significantly greater percentage area and severity of PCO than those with the hydrophobic acrylic SA60AT IOL 1 year after surgery.     

Neodymium:YAG capsulotomy rates following phacoemulsification with implantation of PMMA, silicone, and acrylic intraocular lenses

BACKGROUND AND OBJECTIVE: Posterior capsular opacification (PCO) is the most common visually disabling sequela of modern cataract surgery. Methods of reducing its incidence include the development of newer surgical techniques and intraocular lens (IOL) materials and designs. The aim of this study was to compare the incidence and time interval of development of PCO, and the requirement of laser capsulotomy in patients implanted with a polymethylmethacrylate (PMMA), silicone, or acrylic IOL. PATIENTS AND METHODS: The data of 340 consecutive patients who underwent phacoemulsification and implantation ofa PMMA, silicone, or acrylic intraocular lens were analyzed. The aim of this study was to compare the incidence and time interval of development of PCO, and the requirement of laser capsulotomy in patients implanted with a PMMA, silicone, or acrylic IOL. RESULTS: The incidence of PCO was found to be significantly less in the acrylic group (6.5% as compared to 21.74% and 26.6% in the PMMA and silicone groups, respectively; P = 0.01297 and 0.0039). Most patients (65%) exhibiting PCO in the PMMA group developed it within the first six months. In the silicone group, development of PCO was delayed. In 60% of patients, it appeared 18 months after surgery. Neodymium:YAG capsulotomy was required in 45% and 60% of patients developing PCO in the PMMA and silicone groups, respectively, while it was required in only 1 of the 4 patients developing PCO in the acrylic group. CONCLUSION: This study indicates that implantation of an acrylic IOL helps reduce the incidence of PCO as well as the need for Nd:YAG capsulotomy. PMMA IOLs require Nd:YAG capsulotomy earlier in the postoperative period as compared to silicone IOLs.     

Results of hydrophilic acrylic,hydrophobic acrylic,and silicone intraocular lenses in uveitic eyes with cataract: comparison to a control group

PURPOSE: To evaluate the uveal and capsular biocompatibility of hydrophilic acrylic, hydrophobic acrylic, and silicone intraocular lenses (IOLs) in eyes with uveitis. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This prospective study comprised 72 eyes with uveitis and 68 control eyes having phacoemulsification and IOL implantation by 1 surgeon. Patients received 1 of the following IOLs: foldable hydrophilic acrylic (Hydroview, Bausch & Lomb), hydrophobic acrylic (AcrySof, Alcon), or silicone (CeeOn 911, Pharmacia). Postoperative evaluations were at 1, 3, and 7 days and 1, 3, and 6 months. Cell reaction was evaluated by specular microscopy of the anterior IOL surface and the anterior and posterior capsule reaction, by biomicroscopy. RESULTS: Small round cell deposition was observed on all IOLs in the immediate postoperative period, especially in eyes with uveitis. This reaction decreased 3 to 6 months after surgery. Although the CeeOn 911 had a higher mean grade of small cells, there was no statistical difference between the 3 IOL types after 6 months in the uveitis and control groups. Foreign-body giant cells (FBGCs) increased after 1 week to 1 month. The AcrySof IOLs had the highest number of FBGCs; after 6 months, there was a statistically significant difference between the AcrySof and Hydroview uveitis groups (P =.036) and the AcrySof and CeeOn 911 uveitis groups (P =.003) but there was no difference among the 3 IOL types in the control group. Lens epithelial cell outgrowth persisted on the Hydroview IOLs in control eyes and regressed on all 3 IOL types in uveitic eyes and on the AcrySof and CeeOn 911 IOLs in control eyes (P =.0001). Anterior capsule opacification (ACO) was more severe on all IOL types in uveitic eyes and on the CeeOn 911 IOL in control eyes. Posterior capsule opacification (PCO) was more severe in uveitic eyes. The Hydroview group had more severe PCO than the AcrySof and the CeeOn 911 groups in uveitis and control eyes. Six months postoperatively, the difference was significant (P =.0001). There was no significant difference between the AcrySof and CeeOn 911 IOLs. CONCLUSIONS: Intraocular lens biocompatibility is inversely related to inflammation. Hydrophilic acrylic material had good uveal but worse capsular biocompatibility. Hydrophobic acrylic material had lower uveal but better capsular biocompatibility. Silicone showed a higher small cell count (mild) and more severe ACO but achieved PCO results comparable to FBGC results and better than those with the AcrySof lens 6 months after surgery. Despite the differences in IOL biocompatibility, all patients benefited from the surgery.     

白内障手术后后囊膜混浊的量化比较

目的 评估白内障术后疏水件丙烯酸人工晶状体SensarAR40e和硅胶人工晶状体的后囊膜混浊(PCO),并用能客观评估PCO的软件量化分析.方法 共选择98只眼行标准的超声乳化白内障吸除术,人工晶状体囊袋内固定.所有眼随机植入Sensar AR40e或硅胶人工晶状体,但同一患者植入的人工晶状体必须不同.在第1年和第2年时后照法拍摄后囊膜图像,通过去除浦肯野反光、增强对比度、过滤后增强低密度的PCO等方法处理后用POCO软件分析对比.结果 术后1年疏水性丙烯酸人工晶状体PCO为(0.32±0.13)%硅胶人工晶状体为(0.39±0.17)%(P=0.37).2年时疏水性丙烯酸人工晶状体PCO为(0.42±0.20)%,硅胶品状体为(0.34±0.18)%(P=0.50).患者术后1年,2年时疏水性丙烯酸人工品状体PCO的严重级别分别是(0.50±0.30)和(0.82±0.58),‘亏硅胶人工晶状体的(0.63±0.35)和(0.55±0.35)相比,无统计学意义(P＜0.05).结论 PCO后囊膜混浊量化分析系统提供了客观而且可重复性强的量化PCO的方法,也是研究预防PCO技术的有力工具.     

Comparison of the outcome of implantation of hydrophobic acrylic versus silicone intraocular lenses in pediatric cataract: prospective randomized study

Objective: To compare the postoperative performance of hydrophobic acrylic and silicone square-edge intraocular lenses in pediatric cataract.Design: Prospective randomized study.Participants: Forty-one eyes of 41 children (age 1 month to 8 years) with congenital or developmental cataract.Methods: Children were randomly divided into 2 groups. All participants underwent phacoaspiration, primary posterior capsulotomy, and anterior vitrectomy. Group A (n = 21) eyes were implanted with acrylic hydrophobic AcrySof SA60AT intraocular lenses (IOLs), and those of Group B (n = 20) were implanted with silicone Tecnis Z9000 IOLs. The children were evaluated for anterior chamber reaction, IOL position, posterior capsular opacifica-tion (PCO), intraocular pressure, best-corrected visual acuity (BCVA), corneal status, and refractive errors.Results: Postoperatively, 2 eyes in each group had significant anterior chamber reaction with fibrin membrane formation. IOLs were in the capsular bag in all but 1 eye in both groups. Seven eyes in the acrylic group and 6 eyes in the silicone group achieved visual acuity of 20/40 or better. None of the eyes showed glaucoma. BCVA at 1 year was similar in both groups. In the acrylic hydrophobic group, 14 eyes needed hypermetropic correction and 7 eyes were myopic, and in the silicone group 10 eyes had myopia and 10 eyes had hypermetropia at 1 year postoperatively. PCO at 1 yearfollow-up was more common in eyes implanted with acrylic hydrophobic IOLs (5 eyes) than silicone IOLs (2 eyes).Conclusions: Both square-edge hydrophobic acrylic and silicone IOLs were found to be compatible and safe for use in pediatric cataract surgery with similar visual axis clarity and postoperative outcome.     

Effect of intraocular lens optic edge design and material on fibrotic capsule opacification and capsulorhexis contraction

PURPOSE: To examine the influence of intraocular lens (IOL) optic edge design and optic material on fibrosis of the anterior and peripheral posterior capsules and on capsulorhexis contraction. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: This randomized controlled patient- and examiner-masked study comprised 210 eyes of 105 patients with bilateral age-related cataract. In Group 1 (n = 53), the Sensar OptiEdge AR40e hydrophobic acrylic IOL with a sharp posterior optic edge was compared with the AR40 acrylic IOL with a round edge. In Group 2 (n = 52), the ClariFlex OptiEdge silicone IOL with a sharp posterior optic edge was compared with the PhacoFlex SI-40 silicone IOL with a round edge All IOLs were manufactured by Advanced Medical Optics, Inc. Standardized digital slitlamp images of anterior capsule opacification (ACO) and fibrotic posterior capsule opacification (PCO) were taken 1 year postoperatively, and digital retroillumination images were taken at 1 week and 1 year. The intensity of fibrotic PCO was graded subjectively (score 0 to 4), ACO was graded objectively (score 0% to 100%), and the capsulorhexis area (mm(2)) was determined objectively. RESULTS: One year after surgery, the mean ACO score was 32% in eyes with the sharp-edged acrylic IOL and 29% in eyes with the round-edged acrylic IOL (P<.05). In the silicone group, the mean was 31% and 26%, respectively (P<.05). The mean fibrotic PCO score was lower in eyes with a sharp-edged acrylic IOL than in eyes with a round-edged acrylic IOL (0.26 and 0.93, respectively; P<.05) and in eyes with a sharp-edged silicone IOL than in eyes with a round-edged silicone IOL (0.24 and 0.82, respectively; P<.001). At 1 year, the mean capsulorhexis area was statistically significantly smaller in eyes with a sharp-edged silicone IOL than in eyes with a round-edged silicone IOL (P<.05). CONCLUSIONS: Acrylic and silicone IOLs with the sharp OptiEdge design led to significantly less fibrotic PCO but more ACO than round-edged acrylic and silicone IOLs. The sharp-edged silicone IOL caused significantly more capsulorhexis contraction than the round-edged silicone IOL and both acrylic IOLs.     

Aqueous flare induced by heparin-surface-modified poly(methyl methacrylate) and acrylic lenses implanted through the same-size incision in patients with diabetes.

PURPOSE: To compare the degree of blood-aqueous barrier (BAB) breakdown in eyes of diabetic patients after phacoemulsification and implantation of heparin-surface-modified poly(methyl methacrylate) (PMMA) or soft hydrophobic acrylic intraocular lenses (IOLs) performed using the same technique with the same incision size to determine the influence of the IOLs on postoperative inflammation independent of other surgical factors. SETTING: Department of Ophthalmology, University of Paris XIII, Bobigny, France. METHODS: In a prospective study, 44 eyes of 31 diabetic patients with or without mild to moderate diabetic retinopathy were randomly assigned to receive an HSM PMMA IOL (22 eyes) or a soft hydrophobic acrylic IOL (22 eyes) after standardized phacoemulsification surgery. Both types of IOLs had a 6.0 mm optic, were inserted unfolded, and were placed in the bag through a calibrated 6.0 mm superior scleral incision. Anterior chamber flare was measured preoperatively and 1, 7, 30, and 240 days postoperatively using the Kowa 500 laser flare meter. RESULTS: The mean flare value was higher on the first postoperative day in both groups. There were no statistically significant between-group differences in flare scores or clinical parameters preoperatively or at any postoperative visit. CONCLUSIONS: No significant difference was observed in inflammation between eyes having HSM PMMA IOL implantation or those having soft hydrophobic acrylic IOL implantation through the same-size incision. This indicates that hydrophobic acrylic and HSM PMMA materials induce the same degree of BAB breakdown after phacoemulsification in eyes of diabetic patients.     

Inflammation after phacoemulsification in diabetic retinopathy. Foldable acrylic versus heparin-surface-modified poly(methyl methacrylate) intraocular lenses

PURPOSE: To evaluate inflammation after cataract surgery in patients with nonproliferative diabetic retinopathy (NPDR) and compare results with 2 intraocular lenses (IOLs): a foldable hydrophobic acrylic and a heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA). SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: Patients with NPDR were randomized for implantation of an HSM PMMA IOL (811C, Pharmacia) through a 6.0 mm sclerocorneal incision (30 patients) or a foldable hydrophobic acrylic IOL (AcrySof, Alcon) through a 4.0 mm sclerocorneal incision (32 patients). Both IOLs had 6.0 mm optics. All patients were treated according to a standardized protocol. The degree of flare in the anterior chamber was measured with the Kowa 1000 laser flare-cell meter 1 day preoperatively and 1 day, 1 week, and 1 and 3 months postoperatively. RESULTS: In both IOL groups, flare was highest on the first postoperative day and decreased to preoperative levels by 3 months after surgery. There was no statistically significant difference in relative flare values between the 2 groups. CONCLUSION: There was no difference in postoperative inflammation in eyes with a foldable hydrophobic acrylic IOL implanted through a small incision and those with a rigid HSM PMMA IOL. Postoperative inflammation results indicate that the lenses are equally suitable for the use in patients with diabetic retinopathy.     

Comparison of clinical results between heparin surface modified hydrophilic acrylic and hydrophobic acrylic intraocular lens

PURPOSE. To compare the clinical results of heparin surface modified (HSM) hydrophilic acrylic intraocular lens (IOL) with those of hydrophobic acrylic IOL. METHODS. One hundred patients with cataract were randomized to receive one of acrylic foldable IOLs after phacoemulsification: HSM hydrophilic acrylic IOL (n=50) BioVue3(R) (BioVue, OII, Ontario, CA, USA) and hydrophobic acrylic IOL (n=50) Sensar(R) (AR40e, AMO, Santa Ana, CA, USA). Bestcorrected visual acuity and refractive error were measured at 1 week, 2 months, 6 months and 12 months after surgery in both IOL groups. To assess posterior capsular opacification (PCO), digital retroillumination image of posterior capsule was analyzed at 12 months using POCOman software. RESULTS. Best-corrected visual acuity (log MAR) was 0.032+/-0.082 in BioVue3(R) group and 0.034+/-0.077 in Sensar(R) group at 12 months. There was no statistically significant difference between the two groups (p=0.554). Refractive error was -0.247+/-0.821 diopter in BioVue3(R) group and -0.264+/-0.808 diopter in Sensar(R) group at 12 months. There was no statistically significant difference of refractive error between the two groups (p=0.909). At 12 months, BioVue3(R) IOL group had a lower percentage area and severity of PCO than Sensar(R) group. However, it was not statistically significant (p=0.349, p=0.288). No Nd:YAG capsulotomy was performed in BioVue3(R) group while it was required in two eyes (4.0%) in Sensar(R) group. CONCLUSIONS. There was no statistically significant difference of postoperative visual acuity, refractive error and degree of PCO between HSM hydrophilic acrylic IOL and hydrophobic acrylic IOL.     

Position of anterior capsulorhexis and posterior capsule opacification

PURPOSE: To evaluate whether the position of the anterior continuous curvilinear capsulorhexis influences the rate of posterior capsule opacification (PCO). METHODS: A total of 119 patients, aged 61-86 years, underwent cataract surgery with phacoemulsification performed by a single surgeon. The patients were randomized to implantation with either a silicone intraocular lens (IOL) (SI40NB, Allergan) or an AcrySof IOL (MA60BM, Alcon). Three years after surgery, the rate of PCO was analysed using the evaluation of posterior capsule opacification computer software (EPCO). The results were related to the capsulorhexis position, which was assessed with a retroillumination photograph. RESULTS: If the capsulorhexis was located partially or completely off the optics of the IOL, compared to totally on the IOL, significantly more PCO was found (p = 0.0014). When comparing within each IOL type, patients with AcrySof IOLs were found to have significantly less PCO when the capsulorhexis was totally on the optic (p = 0.0048). This difference was also significant in the silicone group (p = 0.041). CONCLUSION: A relatively small and central capsulorhexis allowing for the complete covering of the IOL optics by the rhexis edges seems to protect against PCO in cataract surgery, with both round-edged silicone IOLs and sharp-edged hydrophobic acrylic IOLs.     

Course of postoperative inflammation after implantation of 4 types of foldable intraocular lenses.

PURPOSE: To compare the course of postoperative inflammation after small incision cataract surgery with implantation of 4 types of foldable intraocular lenses (IOLs). SETTING: Department of Ophthalmology, University Hospital of Vienna, Austria. METHODS: One hundred twenty eyes were prospectively randomized to receive a foldable silicone (Pharmacia 920), hydrogel (Bausch & Lomb Hydroview), methyl methacrylate/hydroxyethyl methacrylate (Mentor MemoryLens), or acrylic (Alcon AcrySof) IOL. All surgery was performed by the same experienced surgeon using a standardized surgical protocol: clear corneal incision, capsulorhexis, phacoemulsification, and in-the-bag implantation of the IOL. All patients received standardized postoperative medication and follow-up. Postoperative inflammation was evaluated by measuring aqueous flare preoperatively and 1, 3, 7, 14, 28, 90, and 180 days after surgery using the Kowa 1000 laser flare-cell meter. RESULTS: Except on the first day after surgery, when the AcrySof group had higher flare values than the other groups (P = .0265), no significant differences were found up to 6 months. Re-establishment of the blood-aqueous barrier was similar in eyes with the AcrySof, Hydroview, and MemoryLens IOLs; the course of postoperative inflammation was different in eyes with the silicone IOL. CONCLUSION: Comparison of postoperative flare values after implantation of 4 foldable IOLs showed no clinically relevant differences in the course of postoperative inflammation.     

Incidence and risk factors of Nd:YAG capsulotomy after phacoemulsification in non-diabetic and diabetic patients

PURPOSE: To estimate the cumulative incidence and identify the risk factors of posterior capsule opacification (PCO) that required Nd:YAG capsulotomy in non-diabetic and diabetic patients. METHODS: Retrospective case-note review of 806 consecutive patients that underwent phacoemulsification and intraocular lens (IOL) implantation, 327 (40.6%) of whom were diabetic. RESULTS: The cumulative incidence of Nd:YAG capsulotomy were 10.6%, 14.8%, 21.2% and 28.6% in non-diabetic patients; and 9%, 9.4%, 15.3% and 5.3% in diabetic patients after 1, 2, 3 and 4 years, respectively. A multivariate Cox regression analysis showed that, over the follow-up period, diabetes mellitus was associated with a decreased risk of Nd:YAG capsulotomy (hazard ratio [HR]=0.69; 95% confidence interval [CI] 0.47-0.99; P=0.047), whereas age of 65 years or younger (HR=1.58; 95% CI 1.09-2.27; P=0.02), polymethylmethacrylate (PMMA) (HR=3.98; 95% CI 1.60-9.95; P=0.003) or plate-haptic silicone IOLs (HR=3.75; 95% CI 1.60-8.80; P=0.002) in comparison with three-piece silicone IOLs, postoperative inflammation (HR=2.62; 95% CI 1.56-4.42; P<0.001) and pars plana vitrectomy (HR=1.85; 95% CI 1.20-2.83; P=0.005) were associated with an increased risk. Subgroup analysis showed that in non-diabetic patients, male gender (HR=1.63; 95% CI 1.04-2.57; P=0.03) was an additional risk factor and in diabetic patients there was no significant association between diabetes type, duration or retinopathy grade and the risk of Nd:YAG capsulotomy. CONCLUSION: Although diabetes mellitus appears to be associated with a lower long-term incidence and a decreased risk of Nd:YAG capsulotomy, younger age, pars plana vitrectomy, postoperative inflammation, plate-haptic silicone and PMMA IOLs in addition to male gender in non-diabetic patients appear to be associated with a greater risk. Estimation of the incidence and risk factors of PCO should help in patient counselling and to design methods to reduce or prevent its development.     

Inflammation after implantation of hydrophilic acrylic,hydrophobic acrylic,or silicone intraocular lenses in eyes with cataract and uveitis: comparison to a control group

PURPOSE: To compare the course of inflammation after small-incision cataract surgery with implantation of 1 of 3 types of foldable intraocular lenses (IOLs) in eyes with uveitis. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: Seventy-four eyes with uveitis and cataract and 68 control eyes with cataract were prospectively selected to receive a foldable hydrophilic acrylic (Hydroview, Bausch & Lomb), hydrophobic acrylic (AcrySof, Alcon), or silicone (CeeOn 911, Pharmacia) IOL. All surgery was performed by the same surgeon using a standardized protocol: clear corneal incision, capsulorhexis, phacoemulsification, and in-the-bag IOL implantation. Preoperative and postoperative inflammation was evaluated by measuring aqueous flare preoperatively and 1, 3, 7, 28, 90, and 180 days after surgery using the Kowa FC-1000 laser flare-cell meter. All uveitic eyes were in remission for at least 3 months before surgery. RESULTS: In the uveitic eyes, there was no statistically significant difference in the postoperative course of flare and cell among the 3 IOL groups. Six months after surgery in uveitic eyes, flare values reached preoperative levels and the cell count was lower than preoperatively in all 3 IOL groups. Relative flare values were higher in the eyes with uveitis and a CeeOn 911 IOL; however, the difference between this group and the 2 acrylic IOL groups was not significant. CONCLUSIONS: There were no significant differences in inflammation after implantation of foldable IOLs in uveitic eyes. Although absolute flare values and cell counts in eyes with uveitis were higher than in control eyes, primarily because of a damaged blood-aqueous barrier (BAB), BAB recovery was similar between the 2 groups. The changes in the BAB indicate that foldable IOL implantation is safe in uveitic eyes.     

Influence of three-piece and single-piece designs of two sharp-edge optic hydrophobic acrylic intraocular lenses on the prevention of posterior capsule opacification: a prospective, randomised, long-term clinical trial

BACKGROUND: Posterior capsule opacification (PCO) is still a major long-term complication of modern cataract surgery. We evaluated the impact of sharp-edged intraocular lenses (IOLs) with different haptic designs made from the same hydrophobic acrylic material on posterior and anterior lens capsule opacification. SETTING: Eye clinic of Kaunas University of Medicine, Lithuania. Prospective randomised clinical study. METHODS: Seventy-four eyes of 74 patients scheduled for cataract surgery were included in a prospective randomised clinical study. Thirty-seven eyes of 37 patients received a three-piece acrylic hydrophobic (AcrySof, MA3OBA, Alcon) IOL; and thirty-seven eyes of 37 patients received a one-piece acrylic hydrophobic (AcrySof, SA3OAL, Alcon) IOL. Visual acuity, anterior capsule opacification (ACO), capsular folds, capsulorrhexis/optic overlapping and posterior capsule opacification (PCO) were evaluated. ACO was assessed subjectively. PCO values in the entire IOL optic area and in the central 3 mm optic zone were assessed using a photographic image-analysis system (EPCO2000). Follow-ups were performed postoperatively at 1 day, 6 months, 1 year and 2 years. RESULTS: There were no significant differences in best corrected visual acuity, grade of ACO and capsulorrhexis/optic overlapping between IOL types during the follow-up period. Patients in the one-piece acrylic hydrophobic IOL group more frequently presented with capsular folds behind the IOL optic area than those in the three-piece IOL group. In the three-piece acrylic hydrophobic IOL group, PCO values (mean (SD)) of the entire IOL optic area were significantly lower six months postoperative (three-piece: 0.002 (0.009); one-piece: 0.007 (0.017); p=0.04), one year postoperative (three-piece: 0.004 (0.016); one-piece: 0.026 (0.041); p=0.001) as well as one year postoperative in the central 3 mm optic zone (three-piece: 0.000 (0.0002); one-piece: 0.019 (0.049); p=0.001). However, two years postoperative, the PCO values of the groups did not show significant differences (entire IOL optic area: three-piece, 0.136 (0.223); one-piece, 0.154 (0.190); p=0.18; central zone: three-piece, 0.023 (0.065); one-piece: 0.020 (0.039); p=0.44). CONCLUSION: The 2 year follow-up after cataract surgery showed no significant difference in ACO and PCO development between three-piece and one-piece acrylic hydrophobic intraocular lenses.     

Optical coherence tomography evaluation of posterior capsule opacification related to intraocular lens design

PURPOSE: To evaluate posterior capsule opacification (PCO) and the impact of different intraocular lens (IOL) models on PCO characteristics using optical coherence tomography (OCT). METHODS: Eighty-three eyes with PCO (fibrosis or pearl type) and 32 pseudophakic eyes without PCO were included. Horizontal 3.0 mm long OCT scans of the posterior capsule were obtained. Measurements and means of the peak posterior capsule intensity (PCI) and posterior capsule thickness (PCT) (distance between 2 spikes at posterior capsule) at 3 scan points were recorded. The PCI and PCT were compared with best corrected visual acuity (BCVA) and IOL data. RESULTS: The PCT was high for IOLs with a rounded edge (P = .001) and with poly(methyl methacrylate) (PMMA) IOLs (P<.001). If the IOL optic was concave-convex, the PCT was higher than if the optic was biconvex (P = .001). The PCT of hydrophilic acrylic IOLs was higher than of hydrophobic acrylic IOLs (P = .04). Multivariate analysis of PCT showed that PMMA was the only factor statistically associated with PCT (P = .02). The worse logMAR BCVA correlated significantly with a higher PCT value (P<.001) but not with PCI (P = .42). An IOL size of 12.5 mm was related to fibrosis-type PCO (odds ratio, 3.14; P = .04). CONCLUSIONS: The PCT was most affected by IOL characteristics. Poly(methyl methacrylate) IOLs and IOLs with rounded edges were associated with higher PCT. Hydrophilic acrylic IOLs were associated with greater PCT than hydrophobic IOLs. Posterior capsule thickness was a factor in decreased BCVA.     

Elapsed time for capsular apposition to intraocular lens after cataract surgery

OBJECTIVE: To examine when the anterior and posterior lens capsule completely become apposed to optics of silicone and acrylic intraocular lenses (IOLs) implanted after cataract surgery and to determine whether the different IOL materials influence the timing of completion of capsular contact. DESIGN: Randomized controlled clinical trial. PARTICIPANTS: Seventy eyes of 70 patients who were scheduled to undergo cataract surgery were randomly assigned to two groups using random number tables based on the type of IOL implanted: silicone or acrylic. Thirty-two patients in each group completed the follow-up. INTERVENTION: All eyes underwent phacoemulsification surgery with implantation of either a silicone or acrylic IOL. All IOLs were accurately placed into the capsular bag. MAIN OUTCOME MEASURES: Contact of the anterior and posterior lens capsule with the IOL optic surface was evaluated using the Scheimpflug videophotography system at 3, 5, 7, 9, 11, 14, 21, and 28 days after surgery. The postoperative day at which each capsule was completely apposed to the IOL optic was determined. In addition, anterior chamber depth was also measured. RESULTS: The anterior capsule was in contact with the IOL optic on the same day or earlier than the posterior capsule in all patients. Complete apposition of the IOL was observed significantly earlier with silicone IOLs than with acrylic IOLs with both the anterior capsule (6.2 versus 3.6 postoperative days; P < 0.0001) and the posterior capsule (11.1 versus 7.4 postoperative days; P = 0.0339). No significant change in mean anterior chamber depth was observed with the silicone IOL, whereas there was significant anterior shift after implantation of the acrylic IOL. CONCLUSIONS: Capsular contact with the IOL optic is completed within approximately 8 days after cataract surgery with silicone IOLs and 11 days with acrylic IOLs. Complete apposition to both the anterior and posterior capsule was significantly earlier with silicone IOLs than with acrylic IOLs.     

后发性白内障相关因素的临床研究

目的观察超声乳化白内障吸除联合折叠人工晶状体植入术后后发性白内障(posteriorcapsuleopacification,PCO)发生的相关因素及其特点。方法随访观察394例(440只眼)白内障患者超声乳化白内障吸除联合囊袋内折叠人工晶状体植入术后的视力,用内置数码摄像头Zeiss120裂隙灯进行眼底后反光裂隙照相,转化成数码图像输入计算机,观察人工晶状体位置、连续环形撕囊和后囊膜混浊等情况。随访时间2～58个月,平均14个月。按照晶状体类型共分为6组Sensar组113例(123只眼),Acrysof三片组129例(157只眼),Acrysof一片组79例(84只眼),SC60B组23例(26只眼),硅凝胶组50例(50只眼)。获得的照片使用德国EPCO2000软件分析,对PCO程度进行评分并将各组进行比较分析。结果完全没有PCO的有19只眼(占4.32%),存在PCO的有421只眼(占95.68%),PCO波及瞳孔中央3mm的有274只眼(占62.27%)。按人工晶状体光学面材料分组的两组中,对应PCO数值进行比较,总分差异无显著性(t=1.470,P=0.143);按照襻的成角分组的四组中,所对应的PCO数值中1级混浊的数值比较,差异有显著性(F=4.054,P=0.007);按边缘设计不同分组的两组中,对应PCO数值比较,总分差异有显著性(t=3.763,P=0.0001);根据连续环形撕囊分组的3组中,所对应的PCO数值比较,总分差异有显著性(F=3.689,P=0.026)。结论后囊膜混浊的发生与人工晶状体材料无相关性;襻与光学面成角为10°的人工晶状体对PCO的早期形成有抑制作用;直角边缘设计可以减少PCO的形成;连续环形撕囊口完全覆盖人工晶状体光学面抑制了后囊膜混浊的发生几率。