Cumulative probability of neodymium: YAG laser posterior capsulotomy after phacoemulsification

PURPOSE: To retrospectively analyze the cumulative probability of neodymium:YAG (Nd:YAG) laser posterior capsulotomy after phacoemulsification and to evaluate the risk factors. SETTING: Ando Eye Clinic, Kanagawa, Japan. METHODS: In 3997 eyes that had phacoemulsification with an intact continuous curvilinear capsulorhexis, the cumulative probability of posterior capsulotomy was computed by Kaplan-Meier survival analysis and risk factors were analyzed using the Cox proportional hazards regression model. The variables tested were sex; age; type of cataract; preoperative best corrected visual acuity (BCVA); presence of diabetes mellitus, diabetic retinopathy, or retinitis pigmentosa; type of intraocular lens (IOL); and the year the operation was performed. The IOLs were categorized as 3-piece poly(methyl methacrylate) (PMMA), 1-piece PMMA, 3-piece silicone, and acrylic foldable. RESULTS: The cumulative probability of capsulotomy after cataract surgery was 1.95%, 18.50%, and 32.70% at 1, 3, and 5 years, respectively. Positive risk factors included a better preoperative BCVA (P =.0005; risk ratio [RR], 1.7; 95% confidence interval [CI], 1.3-2.5) and the presence of retinitis pigmentosa (P<.0001; RR, 6.6; 95% CI, 3.7-11.6). Women had a significantly greater probability of Nd:YAG laser posterior capsulotomy (P =.016; RR, 1.4; 95% CI, 1.1-1.8). The type of IOL was significantly related to the probability of Nd:YAG laser capsulotomy, with the foldable acrylic IOL having a significantly lower probability of capsulotomy. The 1-piece PMMA IOL had a significantly higher risk than 3-piece PMMA and 3-piece silicone IOLs. CONCLUSIONS: The probability of Nd:YAG laser capsulotomy was higher in women, in eyes with a better preoperative BCVA, and in patients with retinitis pigmentosa. The foldable acrylic IOL had a significantly lower probability of capsulotomy.     

儿童超声乳化白内障吸除联合折叠式人工晶状体植入术

目的 探讨儿童超声乳白内障吸除联合丙烯酸酯（Acrysof)折叠式人工晶状体（intraocular lenses,IOL)植入术的手术疗效。方法 对行超声乳化白内障吸除联合Acysof折叠式OL植入术的超声乳化组患儿61例（76只眼）及行现代囊外白内障摘除联合聚甲基丙烯酸甲酯（polymethylmethacrylate,PMMA)硬性IOL植入术的囊外摘除组患儿59例（77只眼）,术后随访6－18个月,观察、比较术后视力、并发症和Q－开关掺钕钇铝石榴石（Q－switched neodymium:yttrium aluminum garnet,Nd:YAG)激光后囊膜切开手术率的情况。结果 超声乳化组和囊外摘除组脱盲率分别为100％、90．6％;脱残率分别为72．6％、51．5％;后囊膜混浊发生率依次为6．6％、80．5％,Nd：YAG激光后囊膜切开手术率依次为2．6％、64．9％。两组比较,脱盲率差异无显著性（P＞0．05）;脱残率差异有显著性（P＜0．05）;术后各种并发症的发生率和Nd:YAG激光后囊膜切开手术率差异有非常显著性（P＜0．01）。结论 超声乳化白内障吸除联合Acrysof折叠IOL植入术,以手术切口小、组织损伤轻、负压吸引可最大限度清除残存晶状体上皮细胞等特点及IOL材料优良的组织相容性,使手术疗效显著,术后并发症减少;Acrysof折叠式IOL在治疗儿童白内障手术中的远期效果尚待进一步研究。     

Comparison of posterior capsule opacification between fellow eyes with two types of acrylic intraocular lens

PURPOSE: To compare the degree of posterior capsule opacification (PCO) and visual function between fellow eyes that received two different types of hydrophobic acrylic intraocular lenses (IOLs). METHODS: Forty-five patients underwent bilateral phacoemulsification and implantation of an Alcon AcrySof IOL (MA60AC) in one eye and an AMO Sensar IOL (AR40e) in the fellow eye. The PCO density value was measured using the Scheimpflug videophotography system at 1, 6, 12, and 24 months after surgery. The incidence of eyes that required a neodymium:YAG (Nd:YAG) laser capsulotomy, visual acuity, and contrast sensitivity with and without a glare source were also examined. RESULTS: The mean PCO value did not show a significant increase in either the AcrySof MA60AC or Sensar AR40e IOL groups, and was similar between the two groups throughout the 24-month follow-up period. The incidence of Nd:YAG laser capsulotomy was also the same between the groups. No significant difference was found in mean visual acuity between the two IOL groups during the follow-up, and there was no significant difference in photopic or mesopic contrast visual acuity with and without a glare source at 1 and 24 months after surgery. Conclusion: The degree of PCO in eyes with an AcrySof IOL are almost the same as that in eyes with a Sensar IOL, with the results that visual acuity and contrast sensitivity with and without glare are similar.     

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.     

Influence on posterior capsule opacification and visual function of intraocular lens optic material

PURPOSE: To examine the influence of optic material on posterior capsule opacification (PCO) by comparing PCO and visual functions between eyes with an acrylic intraocular lens (IOLs) and those with a silicone IOL of the same optic design and with the same haptics. DESIGN: Randomized clinical trial. METHODS: One hundred patients scheduled for phacoemulsification surgery underwent implantation of an acrylic IOL (AMO Sensar; AR40e) in one eye and implantation of a silicone IOL (ClariFlex) of the same optic design and loops in the fellow eye. Eighty-nine patients (89%) remained for analysis. The PCO value was measured using the Scheimpflug videophotography system at one, three, six, 12, 18, 24, 30, and 36 months postoperatively. The incidence of eyes that required a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy was examined; visual acuity and contrast sensitivity with and without a glare source were also evaluated. RESULTS: The mean PCO value did not increase significantly during follow-up in either the acrylic or silicone IOL group. When comparing the groups, no statistically significant difference was found in the PCO or in the incidence of Nd:YAG capsulotomy, although both tended to be slightly better in the silicone group than in the acrylic group. There was also no significant difference between the groups in visual acuity or in photopic and mesopic contrast sensitivity with or without glare. CONCLUSIONS: When acrylic and silicone IOLs are of the same optic design and with the same haptics, the optic material does not influence the development of PCO enough to impair visual function.     

Posterior vitreous detachment after neodymium:YAG laser posterior capsulotomy

PURPOSE: To determine whether retinal detachment (RD) after neodymium:YAG (Nd:YAG) laser posterior capsulotomy is due to a greater incidence of posterior vitreous detachment (PVD) than in controls and whether vitreous status at the time of capsulotomy is useful in predicting the risk for RD. SETTING: Teaching hospital ophthalmology service. METHODS: Patients having Nd:YAG laser posterior capsulotomy after uneventful cataract surgery (treatment group) were prospectively studied. Fellow eyes that had extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation but no Nd:YAG capsulotomy (no-laser group) formed 1 control group, and eyes that had no cataract surgery (phakic group) formed a second control group. The treatment group comprised 322 eyes; the no-laser group, 97; and the phakic group, 142. Dilated fundus and vitreous examinations were performed at baseline (before Nd:YAG capsulotomy) and 12 months postoperatively. RESULTS: At baseline, the prevalence of PVD was similar in the treatment and no-laser groups (61.8% and 63.9%, respectively; P=.2014) but was significantly lower in the phakic group (50.7%; P=.0151). There was no significant difference among the groups in the development of PVD in eyes with attached vitreous at baseline (17.9%, treatment group; 11.4%, no-laser group; 17.1%, phakic group) (P=.6588). CONCLUSIONS: The prevalence of PVD was significantly higher in eyes after ECCE and IOL implantation than in phakic eyes independent of Nd:YAG laser posterior capsulotomy. Capsulotomy was not associated with a significantly higher incidence of new PVD; therefore, the presence or absence of PVD at the time of capsulotomy is not helpful in assessing the risk for RD in the first year after laser treatment.     

Nd:YAG capsulotomy rates after use of the AcrySof acrylic three piece and one piece intraocular lenses

BACKGROUND/AIM: Acrylic lens size and shape may influence the rate of posterior capsule opacification (PCO) and need for Nd:YAG capsulotomy. The aim of this study is to compare the Nd:YAG capsulotomy rate of the three piece acrylic/PMMA AcrySof MA series lens with the one piece acrylic AcrySof SA series lens. METHODS: 434 eyes of 329 patients who had cataract extraction and implantation of one of four types of intraocular lenses (IOLs) were evaluated for rate of Nd:YAG capsulotomy. 176 eyes received the acrylic AcrySof MA30AC IOL, 71 eyes the acrylic AcrySof MA60AC IOL, 45 eyes the acrylic AcrySof SA30AL IOL, and 142 eyes the acrylic AcrySof SA60AT IOL. RESULTS: The rates of Nd:YAG capsulotomy with the three piece IOL (MA30AC/MA60AC) and the one piece IOL (SA30AL/SA60AT) were 1.2% and 2.1% at 6 months, 2.8% and 5.9% at 12 months, and 3.6% and 7.5% at 24 months, respectively. The incidence of Nd:YAG capsulotomy was higher in patients who received the one piece IOL (p=0.01, log rank test). There was no difference in Nd:YAG capsulotomy rates when comparing lens optic size, age, sex, history of pars plana vitrectomy, and diabetes mellitus. CONCLUSIONS: This study shows a greater incidence of Nd:YAG capsulotomy in patients who receive one piece acrylic AcrySof lenses when compared to those who receive three piece acrylic AcrySof lenses.     

AcrySof acrylic intraocular lens implantation in children: Clinical indications of biocompatibility

PURPOSE: To assess the clinical biocompatibility of AcrySof (Alcon, Ft Worth, Tex) acrylic intraocular lenses (IOLs) in the highly reactive eyes of infants and children. METHODS: A database of 230 pediatric IOL implantations was queried to allow retrospective review of all eyes implanted with an AcrySof IOL. Eyes implanted with polymethyl methacrylate (PMMA) IOLs were also reviewed and were used as a historical comparison group. Follow-up examinations were conducted by the surgeon on postoperative day 1, day 7, week 4, and week 8 and every 3 months during the first year and every 6 months thereafter. The presence of synechiae, lens deposits, and posterior capsule opacification were noted in the record at each visit. Examination notes were photocopied, and data were extracted from each visit note and entered into a computerized database. RESULTS: One hundred and ten eyes had an AcrySof IOL at an average age of 60.4 months and had an average postoperative follow-up of 64.6 weeks. In comparison, 120 eyes had PMMA IOLs inserted at an average age of 71.9 months with an average postoperative follow-up of 136.9 weeks. IOL cell deposits were seen at the slit lamp in 7 of 110 (6.4%) AcrySof lenses as compared with 26 of 120 (21.75%) PMMA lenses (P =.002). Posterior synechiae were seen in 5 of 110 (4.5%) AcrySof lenses as compared with 23 of 120 (19.2%) PMMA lenses (P =.001). Twenty-two AcrySof-implanted eyes had an intact posterior capsule. Twenty-eight PMMA-implanted eyes had an intact posterior capsule. The YAG laser capsulotomy rate was similar in the 2 groups at 45.4% for AcrySof and 50% for PMMA (P =.973). The average time from surgery to YAG posterior capsulotomy was 18.6 months with an AcrySof lens and 18.3 months with a PMMA lens (P =.951; t test). A total of 60 patients (68%) implanted with AcrySof IOLs were able to cooperate for Snellen visual acuities. Of their 67 eyes, 48 (72%) had a 20/40 or better visual acuity at the last follow-up examination, and 63 eyes (94%) had a 20/100 or better visual acuity. Thirty-five eyes (52%) required amblyopia therapy, and patching continues as needed. CONCLUSIONS: The AcrySof IOL is representative of a new group of foldable IOLs made from flexible hydrophobic acrylic material. The AcrySof IOL appears clinically to be biocompatible when placed in the eyes of children despite the increased tissue reactivity known to occur in young patients.     

Influence of intraocular lens material on regeneratory posterior capsule opacification after neodymium:YAG laser capsulotomy

PURPOSE: To evaluate the influence of a neodymium:YAG (Nd:YAG) laser capsulotomy on the morphology and development of regeneratory opacification of the remaining surrounding posterior capsule. SETTING: Department of Ophthalmology, Medical School, University of Vienna, Vienna, Austria. METHODS: Standardized digital retroillumination photographs were taken immediately before and after Nd:YAG laser capsulotomy and at 1 week, 6 months, and 1 to 3 years in 38 eyes of consecutive patients. Changes in regeneratory posterior capsule opacification (PCO) and opacification around the capsulotomy opening were evaluated. The influence of the type of intraocular lens (IOL) material and design (acrylic, n = 8; hydrogel, n = 8; silicone open loop, n = 11; silicone plate haptic, n = 6; poly(methyl methacrylate) [PMMA], n = 5) was assessed. The state of the anterior vitreous surface was examined at the slitlamp in all eyes. RESULTS: In 8 of 17 eyes with a silicone IOL, reduced regeneratory PCO was observed. Massive pearl formation on the margin of the Nd:YAG capsulotomy was typical with silicone IOLs (8 eyes) but also occurred with PMMA IOLs. Eyes with acrylic IOLs had no change in regeneratory PCO after the capsulotomy. Three of 8 eyes with hydrogel IOLs had complete closure of the posterior capsulotomy opening. CONCLUSIONS: Neodymium:YAG laser capsulotomy induced changes in the development and morphology of regeneratory PCO. Silicone and PMMA IOLs led to significant pearl formation on the capsulotomy margin, often combined with a reduction of peripheral regeneratory PCO (silicone). Hydrogel IOLs led to a higher incidence of reclosure of the Nd:YAG capsulotomy opening.     

Posterior capsule opacification: comparison of 3 intraocular lenses of different materials and design

PURPOSE: To compare posterior capsule opacification (PCO) after cataract surgery with implantation of 3 intraocular lenses (IOLs) of different materials and design. SETTING: St. Erik's Eye Hospital, Stockholm, Sweden. METHODS: In this prospective clinical study, 180 patients had standardized phacoemulsification performed by a single surgeon and were randomized to have implantation of a heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA) IOL (809C, Pharmacia & Upjohn), a silicone IOL (SI-40NB, Allergan), or an acrylic IOL (AcrySof MA60BM, Alcon). To morphologically evaluate PCO, retroillumination photographs were obtained and analyzed using Evaluation of Posterior Capsule Opacification computer software. The neodymium:YAG (Nd:YAG) capsulotomy rate was recorded. RESULTS: After 2 years, the HSM PMMA IOL group had significantly more PCO than the silicone and AcrySof IOL groups; the silicone group had significantly more PCO than the AcrySof group (P<.05). The Nd:YAG capsulotomy rate was 20% in the HSM PMMA group, 22% in the silicone group, and 8% in the AcrySof group. CONCLUSION: Patients with an AcrySof IOL developed significantly less PCO than those with a silicone or HSM PMMA IOL with a round-edged design.     

Posterior capsule opacification and neodymium: YAG capsulotomy rates with AcrySof acrylic and PhacoFlex II silicone intraocular lenses

PURPOSE: To compare the incidence and severity of posterior capsule opacification (PCO) and neodymium:YAG (Nd:YAG) capsulotomy rates between AcrySof(R) MA30BA acrylic (Alcon) and PhacoFlex(R) II SI-40NB silicone (AMO) intraocular lenses (IOLs). SETTING: Outpatient Cataract Surgery Center, TLC Eyecare and Laser Center, Jackson, Michigan, USA. METHODS: AcrySof and PhacoFlex II IOLs were implanted in fellow eyes of 156 patients requiring bilateral cataract extraction. The patients were followed for a mean of approximately 3 years for the incidence and severity of PCO and the Nd:YAG capsulotomy rates. RESULTS: Of the 63 eyes that were free of PCO throughout the study, 42 had the AcrySof IOL and 21 had the PhacoFlex II IOL. Of eyes that developed PCO, the mean severity in the AcrySof group was 16% less than that in the PhacoFlex II group. Of the 50 eyes that had an Nd:YAG capsulotomy, 17 were in the AcrySof group and 33 were in the PhacoFlex II group. All differences between groups were statistically significant (P<.05). CONCLUSION: The AcrySof MA30BA IOL was associated with less PCO proliferation and thus fewer Nd:YAG laser posterior capsulotomies than the PhacoFlex II SI-40NB IOL.     

Effect of four different intraocular lenses on posterior capsule opacification

AIM: To evaluate the impact of 4 different intraocular lenses (IOLs) on posterior capsule opacification (PCO) by comparing the neodymium: yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy rates. METHODS: This retrospective study included 4970 eyes of 4013 cataract patients who underwent phacoemulsification and IOL implantation between January 2000 and January 2008 by the same surgeon at one clinic. Four different IOLs were assessed. The outcome parameter was the incidence of Nd:YAG laser posterior capsulotomies. RESULTS: An Nd:YAG laser posterior capsulotomy was performed in 153 (3.07%) of the 4970 eyes. The mean follow-up time was 84mo for all of the IOL groups. The percentage of eyes developing PCO was significantly greater for the acrylic hydrophilic IOLs than for the hydrophobic IOLs, although eyes with acrylic hydrophilic IOLs did not require Nd:YAG laser capsulotomy as soon as eyes with acrylic hydrophobic IOLs. There was no difference between the long-term PCO rates when 1- and 3-piece acrylic hydrophobic IOLs were compared or when IOLs made of the same material but with different haptic angles were compared. CONCLUSION: In this study, eyes with acrylic hydrophilic IOLs were more likely to develop PCO than those with acrylic hydrophobic IOLs. The lens design (1-piece versus 3-piece and varying haptic angles) did not affect the PCO rate.     

Comparative performance of intraocular lenses in eyes with cataract and uveitis

PURPOSE: To evaluate the postoperative outcomes in uveitic eyes after phacoemulsification and posterior chamber intraocular lens (IOL) implantation. SETTING: Multicenter (19) international study. METHODS: This prospective randomized comparative interventional case series comprised 140 eyes of 140 patients who had phacoemulsification and implantation of IOLs of various materials: hydrophobic acrylic (n = 48), silicone (n = 44), poly(methyl methacrylate) (PMMA) (n = 26), or heparin-surface-modified PMMA (HSM PMMA) (n = 22). Preoperative and postoperative grading and control of intraocular inflammation were performed. Clinically significant observations, visual outcomes, and the incidence of postoperative complications were recorded. RESULTS: At the final follow-up, 64 eyes (46.3%) had a best corrected visual acuity of 20/40 or better, an improvement that was highly significant (P <.0001). One day after surgery, the acrylic group had the lowest inflammation values and the silicone group the highest (P =.02). The acrylic group continued to have the lowest inflammation grade values until the 3-month follow-up. The acrylic and HSM PMMA groups had the lowest incidence of relapses. Posterior capsule opacification developed in 48 eyes (34.2%), with the highest incidence in the silicone group. CONCLUSIONS: Phacoemulsification with IOL implantation in selected uveitic eyes was safe and effective. Acrylic IOLs provided a better visual outcome and lower complication rate than IOLs of other materials.     

Nd:YAG laser capsulotomy rates following implantation of square-edged intraocular lenses: polymethyl methacrylate versus silicone versus acrylic

Objective: To study the influence of square-edged intraocular lenses (lOLs) on the development of posterior capsule opacification (PCO) and the requirement for laser capsulotomy.Design: Retrospective study.Participants: Three hundred seventy-seven eyes of 377 patients were included.Methods: All these patients underwent phacoemulsification and implantation of square polymethyl methacrylate (PMMA) (Aurolab), silicone (Tecnis Z9000), acrylic hydrophobic (AcrySof MA60AC and Sensar Optiedge), or acrylic hydrophilic (Akreos Adapt) lOLs with a minimum of 2 years’ follow-up. Only those cases in which Nd:YAG laser capsulotomy had been performed for visually significant PCO were evaluated.Results: Three hundred seventy-seven eyes of 377 patients were included in the study. Follow-up duration ranged from 24 to 54 (mean 40.27, SD 8.42) months. The incidence of PCO requiring Nd:YAG laser capsulotomy was found to be significantly less in the silicone lens group: 1.4% as compared with an incidence of 11.7% in the PMMA lens group (p = 0.018). In the square-edged acrylic group, visually significant PCO requiring Nd:YAG laser capsulotomy was observed in 3.6%, 4.8%, and 6.8% of eyes implanted with AcrySof MA60AC, Sensar Optiedge, and Akreos Adapt lOLs, respectively. In 5 of the 7 eyes (71.4%) exhibiting PCO in the PMMA group, the condition developed within the first 6 months. In the silicone and acrylic group, development of PCO was delayed.Conclusions: The rate of visually significant PCO as well as the need for Nd:YAG laser capsulotomy is influenced by IOL biomaterial in addition to square edge. It is significantly delayed with square-edged foldable acrylic and silicone lOLs compared with square-edged PMMA IOLs.     

Comparison of posterior capsule opacification at 360-degree square edge hydrophilic and sharp edge hydrophobic acrylic intraocular lens in diabetic patients

AIM:To compare posterior capsule opacification (PCO) degree and visual functions after phacoemulsification in eyes implanted with 360-degree square edge hydrophilic acrylic intraocular lens (IOL) (570C C-flex, Rayner) and sharp edge hydrophobic acrylic IOL (Sensar AR40e, AMO) in diabetic patients.METHODS:Sixty diabetic patients underwent uneventful phacoemulsification and randomly implanted one of the two IOLs. The PCO value was measured by retroillumination photographs and Evaluation of Posterior Capsule Opacification (EPCO) 2000 image-analysis software at 1, 6, 12, and 24mo after surgery. Visual acuity, and contrast sensitivity in photopic and mesopic conditions were also examined at each follow up time point. The incidence of eye that required Nd:YAG laser posterior capsulotomy were also compared.RESULTS:There was not any statistically significant difference in PCO scores between Rayner C-flex 570C group and Sensar AR40e group at each follow up time point. Visual acuity, Nd:YAG capsulotomy incidence and contrast sensitivity also had no significant difference during the 24mo follow-up.CONCLUSION: For diabetic patients, Rayner 570C C-flex and Sensar AR40e IOLs are same effective for prevent PCO. The 360-degree square edge design maybe is a good alternative technique to improve PCO prevention.     

Changes in posterior capsule opacification after poly(methyl methacrylate), silicone, and acrylic intraocular lens implantation.

PURPOSE: To prospectively evaluate the progression of posterior capsule opacification (PCO) after poly(methyl methacrylate) (PMMA), silicone, and acrylic intraocular lens (IOL) implantation. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: Three hundred eyes of 300 patients scheduled to have IOL implantation were initially randomized into 3 groups based on IOL type: PMMA, silicone, or acrylic. Of the 300 eyes, 269 completed the follow-up. The PCO density in these eyes was measured 1 week and 3, 6, 12, 18, and 24 months postoperatively using special computer software developed for the Scheimpflug videophotography system. Visual acuity and the incidence of neodymium:YAG (Nd:YAG) laser capsulotomy were also examined. RESULTS: Three months postoperatively and later, the mean PCO value in the PMMA group increased significantly (P <.0001); the increase in the silicone and acrylic groups was not significant. The PCO value in the PMMA group was significantly greater than in the silicone or acrylic group (P <.0001). The PCO value in the acrylic group was slightly less than in the silicone group at 18 and 24 months, but the difference was marginal. The survival rate not requiring Nd:YAG capsulotomy was least in the PMMA group, followed by the silicone and acrylic groups in that order (P <.0001). The mean logMAR visual acuity in the PMMA group increased postoperatively and was worse than in the silicone or acrylic group. CONCLUSIONS: The degree of PCO after PMMA IOL implantation progressed significantly with time, while the progression after silicone and acrylic IOL implantation was slight. Therefore, PCO in eyes with a PMMA IOL was significantly more extensive than in those with a silicone or acrylic IOL and resulted in marked impairment of visual acuity.     

Phacoemulsification without intraocular lens implantation in patients with high myopia: long-term results

PURPOSE: To estimate the cumulative incidence of postoperative retinal detachment (RD), rhegmatogenous retinal lesions requiring argon laser treatments, anterior (ACO) and posterior (PCO) capsule opacification, and neodymium:YAG (Nd:YAG) laser capsulotomy in patients with high myopia who had phacoemulsification without intraocular lens (IOL) implantation. SETTING: Department of Ophthalmology and Neurosurgery, University of Siena, Siena, Italy. METHODS: Seventy-three eyes of 57 patients with high myopia who had phacoemulsification without IOL implantation from 1993 to 1996 were retrospectively reviewed. The mean postoperative follow-up was 62.3 months and the mean axial length, 30.22 mm (range 29.10 to 33.70 mm). The incidence of RD and preoperative and postoperative prophylactic argon laser photocoagulation for rhegmatogenous retinal lesions were assessed. Between 1997 and 2000, ACO was evaluated subjectively and PCO was evaluated using the EPCO photographic image-analysis system. The incidence of Nd:YAG laser capsulotomy was noted. RESULTS: Argon laser photocoagulation was performed in 8 eyes (10.9%) preoperatively and 3 eyes (4.1%) postoperatively. One RD (1.3%) was observed 26 months after surgery; no preoperative or postoperative prophylactic argon laser photocoagulation or Nd:YAG laser capsulotomy was performed in this eye. At 1 year, 49 eyes (67.1%) had mild ACO and 24 (32.8%) had anterior capsule fibrosis. The data did not change during subsequent follow-up visits. At 6 years, the mean PCO grade was 1.109 (range 0.972 to 2.931); an Nd:YAG laser capsulotomy was performed in 12 eyes (16.4%). CONCLUSIONS: Compared with other studies that evaluated the outcomes of highly myopic patients who had cataract surgery with posterior chamber IOL implantation, our patients, who did not have IOL implantation, had a lower incidence of postoperative rhegmatogenous retinal lesions requiring argon laser treatments and a similar incidence of postoperative RD and visually significant PCO.     

Cost-effectiveness analysis of PMMA, silicone, or acrylic intra-ocular lenses in cataract surgery in four European countries

PURPOSE: To compare the cost-effectiveness of different intra-ocular lens (IOL) materials (Hydrophobic acrylic, Polymethylmethacrylate (PMMA), Hydrophilic acrylic and Silicone) implanted after cataract surgery with reference to Nd:YAG laser capsulotomy and Nd:YAG-related complications in four European countries (France, Italy, Germany and Spain). SETTING: A retrospective review of 1,525 patients (eyes), aged 50 to 80 years, operated with phacoemulsification for cataract in 1996 or 1997 in 16 surgical centres (4 per country). METHODS: The study was conducted using a cost-effectiveness approach. Medical charts were reviewed to collect retrospective information during the 3-year period following cataract surgery in order to identify patients who underwent Nd:YAG laser capsulotomy post-operatively. Clinical data were combined with unit costs assessed by experts for Nd:YAG laser capsulotomy and their complications. A cost-effectiveness ratio (cost per patient without Nd:YAG laser capsulotomy intervention) was estimated in relation to each IOL material used in each of the four European countries. RESULTS: Hydrophobic acrylic, specifically Acrysof, was the most cost-effective IOL material in all the countries except Germany where it was second. PMMA had the best ratio in Germany, was second in Spain and only third in Italy and France. Silicone was second in France and ranked third in the other countries, while hydrophilic acrylic had the worst ratio overall in all countries. CONCLUSIONS: Cost-effectiveness ratios of hydrophobic acrylic (Acrysof) were better than those of other types of IOL materials used in most of the countries. Sensitivity analyses were performed to vary the base case analysis to demonstrate the economic importance of the assumptions. In all cases, hydrophobic acrylic IOL material was shown to be a highly cost-effective option.     

两种Nd:YAG激光后囊切开方式对不同材料人工晶状体损伤的观察

目的观察Nd:YAG激光后囊膜切开方式对不同材料的人工晶体(IOL)损伤的情况。方法对86例(124只眼)IOL眼晶状体后囊膜混浊(posterior capsule opacity,PCO)患者随机分为两组行Nd:YAG激光后囊膜切开术。A组64眼采用环行切开后推膜瓣法,人工晶体包括:PMMA23眼、疏水性丙烯酸26眼、硅凝胶15眼。B组60眼行十字形切开法,人工晶体包括:PMMA21眼、疏水性丙烯酸25眼、硅凝胶14眼。术前术后常规眼前段检查、测视力、眼压。结果截囊成功率100%。发生IOL损伤16眼,其中A组6眼(9.38%),B组10眼(16.67%),两种方式对相同材料的人工晶体损伤的机率相似(均p>0.05),不同材料的耐受强弱依次为PMMA、疏水性丙烯酸、硅凝胶,均为轻度损伤。结论两种方式对不同材料损伤的机率依次为硅凝胶、疏水性丙烯酸、PMMA,但环行切开后推膜瓣法可以减少Nd:YAG激光后囊膜切开术IOL损伤机率。     

Hydrophobic Acrylic Intraocular Lens in Both Eyes

 PURPOSE: To report on the clinical findings of a case of late opacification of the hydrophobic acrylic intraocular lens (IOLs) in both eyes after cataract surgery. METHODS: A 79-year-old man with a history of decreased visual acuity and complaints of glare and blurred vision in both eyes over the past 3 years. He had received an uneventful phacoemulsification combined with posterior chamber IOL implantation for senile cataract in both eyes 13 years ago, and had undergone neodymium:YAG(Nd:YAG) laser posterior capsulotomy on both eyes 6 years ago, for posterior capsular opacification (PCO). The optical portion of the IOLs showed uniform gray haze. Binocular posterior capsular laser holes were clearly noted. RESULTS: IOL exchange was performed by the same surgeon on both eyes, three days apart. Postoperatively, the patient's visual acuity was elevated to 6/12 (OD) and 6/9 (OS) at 6 months, and intraocular pressure (IOP) reached 16.8 mmHg (OD) and 18.4 mmHg (OS). Neither glare or blurred vision were observed in either eye. CONCLUSION: IOL exchange can be used to effectively manage clinically significant optic opacification.