Incidence of and risk factors for residual posterior capsule opacification after cataract surgery

PURPOSE: To evaluate the incidence of and determine the risk factors for residual posterior capsule opacification (PCO). SETTING: University of New Mexico Health Sciences Center and the Veterans Administration Medical Center, Albuquerque, New Mexico, USA. METHODS: This study evaluated 194 uneventful cataract surgeries. Immature cataracts were graded for nuclear sclerosis (NS), posterior subcapsular cataract (PSC), and anterior cortical spokes on a 1 to 4 scale. Preoperative Snellen best corrected visual acuity was converted to the logMAR scale. The posterior capsule was examined after polishing and was classified as clear or as having residual opacity. Those with residual capsule opacity were evaluated 6 weeks postoperatively for the presence of visually significant PCO. RESULTS: The incidence of residual capsule opacity was 23% (44 eyes). Seven (54%) of 13 eyes with white mature cataract had residual capsule opacity. In contrast, 37 (20%) of 181 eyes with immature cataract had residual capsule opacity (P = .01). In eyes with immature cataract, the mean preoperative logMAR acuity was +1.14 +/- 0.60 (SD) in the residual capsule opacity group and +0.73 +/- 0.46 in the clear group (P<.001). In eyes with immature cataract, the adjusted odds ratio for each increasing grade of NS was 2.3 and of PSC, 1.8 (P = .002 and P<.001, respectively). Eleven percent (5 eyes) of residual capsule opacities resulted in visually significant PCO 6 weeks postoperatively. All 5 opacities were centrally located at surgery. CONCLUSIONS: Results indicate that aggressive polishing of peripheral or adherent residual capsule opacities is not advisable as only 5 eyes with central residual capsule opacities developed visually significant PCO.     

后发性白内障防治的研究

现代白内障手术已成为治疗白内障的确实可靠的方法,但手术后的后囊混浊的高发率严重地影响了患者术后长期拥有良好的视力。因此,如何防治后发性白内障,一直是眼科医生关注的焦点。本文就目前的研究现状作一综述。     

Incidence of postoperative posterior capsular opacification with types of senile cataracts.

The most frequent postoperative complication in extracapsular cataract surgery is opacification of the posterior capsule. The purpose of this study was to correlate the frequency of capsular opacification with each kind of senile cataract. A total of 566 eyes with cataracts were studied. They had been operated on between 1980 and 1990 using the extracapsular, intercapsular, and phacoemulsification techniques. Our results confirm that senile complete cataracts (mature cataracts) had a significantly lower tendency to produce postoperative capsular opacification than other cataract types (nuclear, cortical, posterior subcapsular).     

Risk Potentiality of Frontline Radiotherapy Associated Cataract in Primary Ocular Adnexal Mucosa-associated Lymphoid Tissue Lymphoma

Purpose

To elucidate risk potentiality of frontline radiotherapy associated cataracts in primary ocular adnexal mucosa-associated lymphoid tissue lymphoma (OAML).

Methods

Data from eight consecutive patients of 41 total OAML patients who had undergone cataract surgery after frontline radiotherapy were analyzed.

Results

The median patient age was 46 years (range, 36 to 69 years). The median total radiation dose was 3,780 cGy (range, 3,060 to 4,500 cGy), and the mean duration from radiation irradiation to cataract surgery was 36.60 ± 8.93 months. Preoperative lens opacification was primarily at the posterior lens subcapsule, and best-corrected visual acuity (BCVA) was 0.43 ± 0.21. Patients underwent the phacoemulsification surgical procedure with posterior chamber intraocular lens insertion. The average BCVA improved to 0.90 ± 0.14 after cataract surgery. Two patients underwent posterior continuous curvilinear capsulorhexis, and one had posterior capsule rupture. For posterior capsule opacification (PCO), three patients received Nd:YAG laser posterior capsulotomy after the initial surgery, and one patient is currently under consideration for laser posterior capsulotomy.

Conclusions

Radiotherapy increased posterior subcapsule opacification at a relatively young age in primary OAML. Phacoemulsification was a manageable procedure without severe complications, and final visual outcomes were good. However, because after-cataracts progressed earlier than did senile cataracts, close follow-up should be considered for PCO management.     

Posterior capsule management in congenital cataract surgery

Management of the posterior capsule significantly affects the outcome of pediatric cataract surgery. Posterior capsule opacification (PCO) is rapid and virtually inevitable in very young children when adult-style cataract surgery is performed and the posterior capsule is left intact. In eyes with pediatric cataract, primary posterior capsulotomy and vitrectomy are considered routine surgical steps, especially in younger children. The site of intraocular lens (IOL) fixation and the surgical technique used also affect the prevalence of PCO. The present systematic review evaluates the options available to prevent PCO or ensure a clear central visual axis after pediatric cataract surgery. Newer approaches to posterior capsule management such as pars plicata posterior capsulorhexis, sutureless vitrectomy, sealed-capsule irrigation, and bag-in-the-lens IOL are discussed. Management of the posterior capsule in the presence of a preexisting posterior capsule defect and posterior capsule plaque and options to treat PCO are also reviewed. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.     

When may the posterior capsule be preserved in pediatric intraocular lens surgery?

PURPOSE: To refine indications for primary posterior capsulotomy (PPC) in conjunction with posterior chamber intraocular lens (PCIOL) implantation for cataract in childhood. DESIGN: Noncomparative case series. PARTICIPANTS: Patients 1 to 13 years old who underwent cataract extraction with intent to preserve the posterior lens capsule and PCIOL implantation between January 1992 and December 1998 at a pediatric hospital. METHODS: Medical records were reviewed to determine the frequency and timing of posterior capsule opacification (PCO) after PCIOL surgery with preservation of an intact posterior capsule. Comparison of pseudophakic PCO rates for groups defined by age and several possible risk factors. Assessment of safety and efficacy for PPC with anterior vitrectomy performed through a limbal incision in cases where the posterior capsule could not be preserved. MAIN OUTCOME MEASURES: Need for neodymium:yttrium-aluminum-garnet laser capsulotomy or surgical membranectomy to treat PCO. RESULTS: PCO occurred in 40% of 30 eyes with intact posterior capsule. Mean follow-up duration was 22 months for eyes that had PCO develop and 24 months for those in which the posterior capsule remained clear. Laser capsulotomy was required for 64% of 14 eyes in the 1- to 6-year-old age range but for only 19% of 16 in the 6- to 13-year-old range (P < 0.05). Mean time from surgery to PCO was 7 months for the younger group and 13 months for the older group. A need for repeated capsulotomy (one eye) or membranectomy with anterior vitrectomy (two eyes) was found only in the younger age group. There was no association of PCO with trauma history, cataract type, residual lens cortex, IOL position, or postoperative fibrin clot. Final vision was possibly compromised as a result of PCO in one eye with amblyopia. None of 24 eyes in which PPC with anterior vitrectomy was performed out of intraoperative necessity before primary PCIOL implantation had secondary opacification develop. No reduction in postoperative vision was attributable to PPC. CONCLUSIONS: PPC seems to be advisable for children less than 6 years old when cataract extraction with PCIOL implantation is performed. Preservation of the posterior capsule remains appropriate for older children with pseudophakia.     

晶状体囊抛光及透明质酸酶预防囊的浑浊

目的探讨晶状体囊抛光并囊袋内注射透明质酸酶预防囊的浑浊和后发性白内障的作用及安全性.方法年龄相关性白内障70例80眼,按常规进行超声乳化吸出人工晶状体植入术.治疗组40眼水分离时用含透明质酸酶1000 IU的必施（BSS）进行,乳化吸出晶状体核和皮质后在黏弹剂的保护下,囊袋内注入含透明质酸酶500IU的BSS,2分钟后用抛光针尖进行晶状体囊抛光,然后注吸清除上皮细胞碎屑,囊袋内植入人工晶状体.对照组40眼则用同等量BSS进行水分离,仅行后囊抛光.术后18月随访,进行角膜内皮、眼底及视网膜电图等检查,并对前、后囊浑浊的情况进行分级.结果术后18月治疗组前、后囊膜浑浊的发生率与对照组相比,差异有统计学意义.角膜内皮损失率与对照组相比,差异无统计学意义.两组眼底检查和视网膜电图检查显示视网膜功能正常.结论晶状体囊袋内注射透明质酸酶联合晶状体囊抛光可以预防囊的浑浊和后发性白内障发生,且眼内应用安全.     

Effect of anterior capsular polishing on the rate of posterior capsule opacification: A retrospective analytical study

AimTo determine whether anterior capsule polishing during cataract surgery done by phacoemulsification has any effect on the rate of posterior capsule opacification.Materials and methodsWe conducted a 3 year retrospective analytical study at our hospital. The medical records of patients who underwent cataract extraction by phacoemulsification with foldable square edge hydrophilic PCIOL between April 2007 and March 2010 were reviewed.The study included 1009 eyes of 950 patients who underwent phacoemulsification with foldable square edge hydrophilic IOL in the bag implantation with anterior capsular polishing. The control group included 981 eyes of 957 patients in whom anterior capsular polishing was not done.Patients in the age group of 45–65 years with well dilating pupils were included in the study. They were evaluated at 1 week, 1 month and 1 year post-operatively. Exclusion criteria included glaucoma, shallow anterior chamber, uveitis, high myopia, pseudoexfoliation, diabetes mellitus, traumatic cataracts, posterior polar cataract, subluxated cataracts, previous ocular surgeries, patients allergic to dilating drops, and steroid intake. Intraoperatively, the exclusion criteria were not achieving the total anterior capsule cover on the IOL optic, sulcus fixated IOL, and any intraoperative complications like posterior capsule rupture. After bimanual irrigation/aspiration, all enrolled patients were randomly assigned to receive either 360 degree anterior capsular polishing or No anterior capsular polishing and results were studied.ResultsThe rate of posterior capsule opacification in the study group and in the control group was not statistically significant.ConclusionThough it was thought that anterior capsular polishing will lead to reduced rate of PCO formation, our study showed that there was no significant difference in PCO formation between the two groups. However, it was seen that the rate of anterior capsule opacification and capsular phimosis showed a significant reduction in cases in which anterior capsular polishing was done.     

Posterior capsule opacification after cataract surgery in patients with diabetes mellitus

PURPOSE: To prospectively compare the degree of posterior capsule opacification (PCO) after cataract surgery in patients with and without diabetes mellitus. SETTING: Sugita Eye Hospital, Nagoya, Japan. METHODS: Forty-two eyes of 42 consecutive diabetes mellitus patients (DM group) and 42 eyes of 42 non-DM patients (control group) scheduled to have cataract surgery were enrolled. The PCO value was determined using the posterior capsule opacification (POCO) system 3, 6, and 12 months after surgery. RESULTS: Posterior capsule opacification values 3 months after surgery did not differ significantly between the 2 groups (P>.05). At 6 and 12 months, the PCO values of the DM group were significantly higher than those of the control group (P = .002 and P = .03, respectively). CONCLUSION: Diabetic patients had significantly more severe PCO after cataract surgery than nondiabetic patients.     

Pulsed electron avalanche knife: new technology for cataract surgery

BACKGROUND: The pulsed electron avalanche knife (PEAK-fc) is a new pulsed electrosurgical device that allows for precise, "cold" and traction-free tissue dissection. AIM: To evaluate the surgical applicability, safety and potential complications of PEAK-fc in complicated cataract surgery. METHODS: The study included five children with congenital cataracts, two patients with advanced senile cataracts, six adults with mature cataracts, three of them with posterior iris synechia, three patients with post-traumatic cataracts with zonulolysis, one patient with intumescent traumatic cataract and three patients with massive anterior capsule opacification. Anterior and posterior capsulotomies, iris synechiolysis, dissection of anterior capsule opacification and fibrotic scar tissue were performed. PEAK-fc was set at voltages of 500-700 V, pulse duration of 0.1 m and repetition rate of 40-100 Hz. RESULTS: Anterior and posterior capsulotomies were successfully and safely performed in all eyes. The edges of capsulotomies appeared sharp, showing only limited collateral damage. PEAK-fc worked best by just gently touching the capsule, thereby avoiding tractional forces or pressure on the lens capsule. Posterior iris synechiae could be released and anterior capsule opacification was dissected without complications. CONCLUSIONS: PEAK-fc is a very helpful cutting device for complicated cases of cataract surgery, especially for mature and congenital cataracts, traumatic zonulolysis or anterior segment complications after intraocular inflammation.     

Migration of lens epithelial cells through haptic root of single-piece acrylic-foldable intraocular lens

PURPOSE: To report a case of posterior capsule opacification after cataract surgery due to lens epithelial cell migration through the haptic root of a single-piece acrylic-foldable intraocular lens. DESIGN: Interventional case report. METHODS: A 60-year-old man with senile cataract underwent phacoemulsification and implantation of single-piece acrylic intraocular lens having thick and wide haptic loops. RESULTS: There were no operative or short-term postoperative complications, and patient's visual acuity was 20/20 on the day following surgery. At 19 months postoperatively, we observed posterior capsule opacity extending from the base of the intraocular lens loops. CONCLUSION: Broad and thick haptic root can be a path through which lens epithelial cells migrate toward the center of the posterior capsule, forming posterior capsule opacification.     

Lens capsule opacification in aphakic and pseudophakic eyes

Background: Posterior capsule opacification (PCO) is the most common complication of lens extraction. Although intraocular lenses (IOLs) are thought to inhibit capsule opacification, the mechanisms by which they do this are poorly understood. This study was done to determine the effects of pseudophakia on secondary cataract and PCO in experimentally lentectomized dogs. Methods: Twenty-four normal dogs were bilaterally lentectomized by phacoemulsification and unilaterally implanted with a plano-convex polymethylmethacrylate IOL. Secondary cataracts and capsule opacification were evaluated at weeks 1, 2, 4, 10, 14, and 20 after surgery by retrolillumination photography, light microscopy, and scanning and transmission electron miscroscopy. Results: The pattern of secondary cataract and PCO in dogs was found to be similar to that in other animal species. Production of new lens material was prominent in the equatorial region, and PCO resulted from fibrous metaplasia of lens epithelium and subsequent capsular fibrosis and wrinkling. The presence of an IOL did not prevent the posterior migration of epithelium, nor did it prevent fibrous metaplasia. The presence of an IOL did, however, minimize the capsule-wrinkling effects of fibroplasia and limit the space available for lentoid formation. Conclusion: In pseudophakic eyes, IOLs influence secondary cataract formation by limiting the space available for lentoid formation and by maintaining a linear scaffolding for lens epithelial fibrous metaplasia.     

Posterior polar cataracts: a predisposition to intraoperative posterior capsular rupture

We performed phacoemulsification or planned extracapsular cataract extraction on posterior polar cataracts in 31 eyes of 22 patients and experienced eight cases of posterior capsular rupture (26%). Capsular rupture occurred during removal of the posterior polar opacity or during cleaning of the posterior capsule after the opacity had been removed. We believe that excessive adherence of the opacity to the posterior capsule and unusual thinness of the capsule predisposed these eyes to posterior capsular rupture.     

Primary posterior capsulorhexis without anterior vitrectomy in pediatric cataract surgery: longer-term outcome.

PURPOSE: To assess the effectiveness of primary posterior capsulorhexis without anterior vitrectomy in preventing posterior capsule opacification (PCO) in pediatric cataract surgery. SETTING: Children's Hospital, Dublin, Republic of Ireland. METHODS: The study comprised 32 eyes of 22 pediatric patients who had cataract extraction between 1994 and 1998. Extracapsular cataract extraction was performed using radiofrequency diathermy capsulorhexis to the anterior and posterior capsules without an anterior vitrectomy. Posterior chamber intraocular lens implantation was performed in 20 eyes. There were 23 congenital, 6 developmental, and 3 traumatic cataracts. RESULTS: Patient age ranged from 1 month to 12 years. Mean follow-up was 19 months (range 6 to 50 months). Twenty-seven of 32 eyes (84.4%) had a clear visual axis at last follow-up. Five eyes required a neodymium: YAG capsulotomy, which was performed a mean of 5 months postoperatively (range 1 to 9 months). The incidence of PCO requiring capsulotomy was 15.6%. CONCLUSION: Primary posterior capsulorhexis without anterior vitrectomy was safe and effective, with a low reopacification rate. Long-term follow-up of this patient cohort is necessary.     

Posterior capsule opacification in pseudophakic eyes--etiopathogenesis, clinical picture, possibilities of prevention and therapy

Posterior capsule opacification (PCO) is a late complication after the cataract surgery, currently occurring most often. The epithelial cells which migrate to the surface of the posterior capsule participate in the mechanism of PCO formation. Clinical opacification of the posterior capsule appears as the foggy form, creasing, pearl mass and fibrosis. PCO can be cured by laser or surgical capsulotomy. The factors influencing a size and intensity of PCO are as follows: age of patient, other diseases, method of surgery and type of the implanted artificial intraocular lens. Prevention against PCO during surgery should include accurate hydrodissection, removing of cortical mass, polishing of the capsule and intracapsular fixation of the lens. It is necessary to carry out further studies on possibilities of PCO prevention.     

Posterior vertical capsulotomy with optic entrapment of the intraocular lens in congenital cataracts--prevention of capsule opacification

PURPOSE: To present a modified surgical technique for preventing posterior capsule opacification (PCO) in children with congenital cataracts and to evaluate its long-term efficacy. SETTING: Department of Ophthalmology, Medical University of Southern Africa, Medunsa, South Africa. METHODS: Anterior and posterior vertical capsulotomy, with optic entrapment of the intraocular lens (IOL) by maintaining the anterior hyaloid, was performed in 68 cataractous eyes of children aged 2 months to 8 years (mean 3 years, 1 month). The posterior capsule was evaluated for at least 5 years for secondary opacification, IOL position, pigmentary deposits on the IOL optic, and the presence of synechias. RESULTS: Sixty-eight eyes maintained a clear visual axis for 5 to 12 years (mean 9 years, 1 month) postoperatively. No secondary procedure was necessary. In all eyes, the IOL remained well centered and entrapped. CONCLUSIONS: Posterior capsulotomy with optic entrapment of the IOL proved to be a safe and efficient surgical procedure for preventing PCO in children with congenital cataracts. Uniting the anterior and posterior capsule in front of the IOL limits the proliferation and migration of Elschnig pearls. An intact anterior hyaloid does not induce capsule opacification in association with optic entrapment; therefore, a vitrectomy is not indicated even in infants under age 5 years. Clear visual axis, centered IOL, and intact vitreous were achieved in this series; this enables a promising long-term prognosis for binocular visual development, especially because surgery was performed early.     

Incidence of posterior capsule opacification in eyes with and without posterior chamber intraocular lenses

The incidence of posterior capsule opacification after extracapsular cataract extraction was significantly lower in eyes implanted with posterior chamber intraocular lenses than in nonimplanted eyes. The number of loops fixated in the bag was significantly smaller in the eyes that became opacified than in those that did not. These findings suggest that the posterior chamber lens suppresses the two processes that lead to opacification: the development of a ring-shaped opacity at the site of contact between the anterior capsule rim and the posterior capsule and the migration of lens epithelial cells toward the center of the capsule. These suppressive effects were greater when the posterior chamber lens was fixated in the bag.     

后发性白内障的发病机制和药物防治的研究现状及前景

后发性白内障是现代白内障术后最常见的并发症。术后晶状体囊残留的晶状体上皮细胞的增殖、迁移、纤维化生是形成后发性白内障的主要原因。目前防治后发障的研究主要集中在药物除去或破坏残留晶状体上皮细胞。实验研究许多细胞毒药以及抑制晶状体上皮细胞生长和纤维化药物可以预防后发障,但目前临床上还没安全、有效的防治白内障方法。     

Nd：YAG激光治疗白内障术后不同类型后发性白内障

目的分析Nd：YAG激光行后囊膜切开术治疗白内障复明手术后不同类型后发性白内障的治疗作用与术后并发症。方法对白内障复明手术后,109例（109眼）后发性白内障依据后囊昆浊形态分为：A组Elschnig珍珠样小体型46例（46眼）,B组纤维化型63例（63眼）。采用十字形切开法或开罐式切开法进行激光后囊膜切开术,比较两组激光术前最佳矫正视力与激光术后最佳矫正视力以及激光术后并发症情况。结果 A、B两组内激光术后最佳矫正视力较激光术前最佳矫正视力改善（P〈0.05）;A组术后眼压升高和房水闪辉明显高于B组（P〈0.05）。结论 Nd：YAG激光是治疗白内障复明手术后不同类型后发障的常用有效的治疗方法,激光术后并发症与后发性白内障类型有关。     

Spontaneous regression of Elschnig pearl posterior capsule opacification

After extracapsular cataract extraction with in-the-bag intraocular lens implantation, a 72-year-old woman had reduced visual acuity from posterior capsule opacification (PCO) resulting from Elschnig pearl proliferation. No capsulotomy was performed, and the PCO decreased spontaneously over time, improving visual acuity and leaving a clear capsule.