Standard Extracapsular Cataract Extraction Research Articles

RETROSPECTIVE INVESTIGATION OF CATARACT MANAGEMENT IN AVIAN SPECIES IN A ZOOLOGIC COLLECTION.

A review of avian cataracts at the Wildlife Conservation Society's Bronx Zoo between 1992 and 2011 was conducted. Ninety cataracts in 54 birds from 42 species were identified. Cataracts were found primarily during examination for ocular abnormalities (29/54, 53.7%) or opportunistically (13/54, 24.1%) and were most commonly diagnosed as mature (22/90, 24.4%). Systemic medical conditions diagnosed in these birds included West Nile virus (4/54, 7.4%), head trauma (3/54, 5.6%), plumbism and Salmonella Pullorum (1/54, 1.9%), Marek's disease (1/54, 1.9%), leukocytosis (1/54, 1.9%), and hyperglycemia (1/54, 1.9%). Cataracts were progressive in seven birds of four species. Unilateral enucleation was performed in 2/54 (3.7%) birds, and 12/54 (22.2%) underwent cataract removal (phacoemulsification in 16 eyes and standard extracapsular cataract extraction in 2 eyes). Concurrent ocular abnormalities, such as corneal scarring and lens-induced uveitis, were seen in 2/18 (11.1%) eyes preoperatively in the group undergoing cataract removal, 2/2 (100%) eyes preoperatively in the group undergoing enucleation, and 33/70 (47.1%) of eyes that did not undergo surgery. For birds undergoing cataract removal, complications included successfully treated cardiorespiratory arrest intraoperatively (1/12, 8.3%) as well as postanesthetic complications of acute respiratory distress and tracheal stricture (2/12, 16.7%). The most common postoperative ocular abnormalities included posterior capsular opacity (4/18 eyes, 22.2%) and corneal scarring (2/18 eyes, 11.1%). Lens cortical regrowth and marked posterior lens capsular opacity occurred in one eye of one bird after phacoemulsification, necessitating a second ocular surgery. A successful outcome, as determined by improved postoperative visual acuity, was seen in 10/12 (83.3%) birds undergoing cataract removal, and 5/12 (41.7%) of these birds were alive >3 yr after surgery. The results of this review will aid clinicians in identifying common stages of cataracts, determining eligibility for cataract surgery, and managing postoperative complications in avian patients.

A comparative study of astigmatism following manual small incision cataract surgery and conventional extracapsular cataract extraction at a tertiary centre in northern india

Objective: To compare the surgically induced astigmatism following two different techniques of cataract surgery-manual SICS (Small Incision Cataract Surgery) and standard ECCE (Extra-Capsular Cataract Extraction). Materials and Methods: Subjects consisted of patients, aged 10-80 years, from both sexes and divided into two groups of 100 each (one eye per patient). One group was operated with manual SICS and the other with standard ECCE technique. Results: The mean surgically induced astigmatism (SIA) in the SICS group during the sixth week postoperative follow up was found to be 0.66D ± 0.60 SD (Standard Deviation) compared to 2.25D ± 1.23 SD in the ECCE group. At 6th week follow up, no patient in the SICS group had SIA more than 3D whereas in the ECCE group 30% of the patients had astigmatism >3 D. The induced astigmatism between the two groups had a p-value of <0.001 which is highly significant. Conclusions: It is concluded that SICS induces less surgically induced astigmatism, less inflammation, less complications influencing the overall visual prognosis and quick stabilization of refraction, hence providing better and rapid visual rehabilitation in the postoperative period as compared to the patients in the ECCE group.

Challenges in the management of paediatric cataract in a developing country.

To review the management of cataract in children in a tertiary hospital in a developing country, and to highlight the challenges therein. The hospital records of children aged 15 years or less that had cataract surgery at University of Nigeria Teaching Hospital, Enugu from 2005 to 2008 were reviewed retrospectively. Information was obtained on bio-data, pre- and post-operative visual acuity (VA), biometry, and type of surgery, use of intraocular lens (IOL) and presence of co-morbidity. SPSS was used for data entry and analysis. The hospital records of 21 children (26 eyes) were analyzed. There were 12 males (57.1%) and 9 females (42.9%). Pre-operative VA could not be assessed in 11 eyes (42.3%), 14 eyes (53.9%) had VA <3/60 and 1 eye (3.8%) had VA 6/60. Biometry was done in only 5 eyes (19.2%). All eyes had standard extracapsular cataract extraction without primary posterior capsulectomy; 12 eyes (46.2%) had posterior chamber intraocular lens (PC-IOL) implant while 13 eyes (50.0%) had no IOL. After 12 weeks of follow up, vision assessment was available in only 15 eyes. With best correction, VA of 6/18 or better was achieved in only 5 eyes (33.3%). Inadequate facilities and inadequate follow up after surgery are some of the challenges in managing paediatric cataract in the developing countries. If these challenges are not addressed, cataract will remain a major cause of childhood blindness and low vision in Africa for many years. There should be collaboration between Paediatric Ophthalmology Centres in industrialized and developing countries to enhance skill transfer. Governmental and International Non-governmental Organizations can go a long way to facilitate this exchange.

Topical Thrombin-Related Corneal Calcification

To report a highly unusual case of corneal calcification after brief intraoperative use of topical thrombin. A 44-year-old man underwent sclerouvectomy for ciliochoroidal leiomyoma, during which 35 UNIH/mL lyophilized bovine thrombin mixed with 9 mL of diluent containing 1500 mmol/mL calcium chloride was used. From the first postoperative day, corneal and anterior lenticular capsule calcifications developed, and corneal involvement slightly enlarged thereafter. A year later, 2 corneal punch biopsies confirmed calcification mainly in the Bowman layer. Topical treatment with 1.5% ethylenediaminetetraacetic acid significantly restored corneal clarity. Six months later, a standard extracapsular cataract extraction with intraocular lens placement improved visual acuity to 20/60. This case suggests that topical thrombin drops with elevated calcium concentrations may cause acute corneal calcification in Bowman layer and on the anterior lens capsule.

Diffuse benign epithelial downgrowth after cataract surgery

Case report: We present an interventional case report of a rare occurrence of diffuse epithelial downgrowth developing after extracapsular cataract surgery and iris prolapse that was successfully treated only by excision of the membrane. A 71-year-old man underwent repositioning of an atraumatic iris prolapse 1 month after uneventful standard extracapsular cataract extraction in his right eye. Over 14 months, a white membrane was observed over almost 80% of the iris surface, reducing visual acuity. Intraocular pressure and results of fundus examination were normal. Peeling and excision of the membrane were performed. Histopathologic analysis was consistent with epithelial downgrowth. At 22 months after the epithelial downgrowth peeling, visual acuity was 6/12, there were no signs of recurrence, and intraocular pressure was normal without any treatment. Comments: Provided a continuous follow-up is possible,simple excision of the membrane can be a successful treatment in selected rare cases of diffuse epithelial downgrowth.

The Relationship Between Ultrasound Characteristics of Human Cataract and in vitro Measurement of Mechanical Characteristics of the Lens after Extracapsular Cataract Surgery

In this paper, the relationship between ultrasound and physical characteristics of the extracted lens has been investigated. A pre-operative examination and assessment of cataract biometry and LOCSIII grade have been applied to 16 patients who had a planned standard extracapsular cataract extraction. Post-operative in vitro measurement of the ultrasonic characteristics of the extracted lenses has also been carried out to calculate the ultrasound attenuation and speed of sound through these lenses. Promptly after finishing the ultrasound measurements, an in vitro evaluation of nucleus with measurement of linear compressibility and the force required to compress a lens to 75% of its original thickness was carried out using a newly purpose-designed device. Attenuation of ultrasound signal across the lens correlates with both measures of lens 'hardness', linear compressibility ( R=−0·673, R2=0·453, P=0·011) and the force required to compress the lens to 75% of its original depth ( R=0·722, R2=0·521, P=0·008). The speed of sound in the lens correlates negatively with lens linear compressibility ( R=−0·383, R2=0·147, P=0·197), but did not reach statistical significance for this sample size. These results provide a sound basis for further research and may have implications for future pre-operative assessment of cataract 'hardness' using ultrasound techniques.

Phacoemulsification: our experience at a large Military Hospital

Cataract surgery by means of phacoemulsification was started at a large Military Hospital in March 2001. First 70 cases in whom phacoemulsification was performed between 15 March 2001 and 31 December 2001 were followed-up and evaluated. The surgical techniques used, complications and post-operative recovery following this new surgical technique have been discussed. Our experience of conversion from standard extracapsular cataract extraction to phacoemulsification has also been shared.

High Volume Sutureless Intraocular Lens Surgery in a Rural Eye Camp in India

To describe the use of small incision sutureless cataract surgery (SISCS) that permits high-volume, high-quality, and low-cost surgery. We compared the speed, safety, and visual results of 1190 surgical techniques performed in a public eye camp in India. Intraocular lenses were received by 97% of patients (1154). Surgical techniques used were SISCS, phacoemulsification, and standard extracapsular cataract extraction (ECCE) technique. Postoperatively, 60.0% attained uncorrected vision of 6/24 or better. There was little difference in visual results or complication rates among the three techniques. The most striking finding is the speed of SISCS, which enables experienced surgeons to perform the technique in 3.8 to 4.2 minutes. We believe this surgical technique is of major importance especially in developing nations facing enormous surgical volumes and limited resources.

EVALUATION OF OCULAR DEVIATIONS AND PTOSIS AFTER CATARACT SURGERY

There is a paucity in world literature of a prospective study on post cataract strabismus and in Indian literature on post cataract ptosis. 150 cataract patients without pre-existing strabismus or ptosis were subjected to standard extracapsular cataract extraction with posterior chamber intraocular lens implantation under 2 point peribulbar anaesthesia and were post-operatively evaluated for strabismus and ptosis. At the end of first week, there were 10/150 (6.67%) cases of strabismus, 13/150 (8.67%) cases of ptosis and 5/150 (3.33%) of both combined, which reduced to 2% each (3/150) at the twelfth week. The probable factors for causation and recovery are being discussed.

A systematic overview of the incidence of posterior capsule opacification

Objective Reported rates of posterior capsule opacification (PCO) vary widely and are based on various definitions of PCO, varying lengths and intervals of follow-up, and the use of different surgical techniques, intraocular lens (IOL) designs, and methods of IOL implantation. This study was designed to obtain a more precise overall estimate of the incidence of PCO and to explore factors that might influence the rate of PCO development. Design A meta-analysis. Methods Published articles were selected for study based on a computerized MEDLINE search of the literature and a manual search of the bibliographies of relevant articles. Articles meeting selected inclusion criteria were reviewed systematically, and the reported data were abstracted and synthesized using the statistical techniques of meta-analysis. Main outcome measure Pooled estimates of the proportion of eyes developing PCO at three postoperative timepoints—1 year, 3 years, and 5 years—were measured. Results There is significant heterogeneity among published rates of PCO. The overall pooled estimates (95% confidence limits) of the incidence of PCO were 11.8% (9.3%–14.3%) at 1 year, 20.7% (16.6%–24.9%) at 3 years, and 28.4% (18.4%–38.4%) at 5 years after surgery. There is no evidence of a significant decline in PCO incidence during the study period. Conclusions Visually significant PCO develops in more than 25% of patients undergoing standard extracapsular cataract extraction or phacoemulsification with posterior chamber intraocular lens implantation over the first 5 years after surgery. Patient characteristics, surgical techniques, and differences in research design and reporting may account for some of the variability in reported rates. However, no specific factors were identified in the authors’ analysis. More precise estimates of incidence and identification of risk factors for PCO will depend on the development of a standardized measurement of PCO and wider adoption of more rigorous study methodology.

Peroperative microbial contamination of anterior chamber aspirates during extracapsular cataract extraction and phacoemulsification

BACKGROUNDThe normal conjunctival flora is one of the main sources of intraocular contamination during cataract surgery. The theory that the positive anterior chamber (AC) pressure during phacoemulsification (phaco), and the...

Posterior Capsule Opacification after Cataract Surgery in Patients with Uveitis

To compare the incidence rate of posterior capsule opacification (PCO) after phacoemulsification and standard extracapsular cataract extraction (P/ECCE) in eyes with antecedent uveitis with the incidence rate in eyes without any history of intraocular inflammation. Review of records of 108 eyes of 78 patients with uveitis and 122 eyes of 106 patients with no uveitis who underwent P/ECCE. Rates of PCO were compared by the log-rank test of differences in the Kaplan-Meier survival curves. Proportional hazards regression models provided estimates of the relative risks of PCO among uveitic compared to nonuveitic eyes. Performance of neodymium: YAG laser posterior capsulotomy was used as a proxy measure for the main outcome of visually significant PCO. Study patients ranged in age from 6 to 81 years (median, 44.5 years) among those with uveitis and 27 to 96 years (median, 68.5 years) among those without uveitis (P = 0.0001). Crude incidence rates for visually significant PCO were 54% over a mean follow-up of 4.3 years in uveitic cases and 40% over a mean follow-up of 3.9 years among nonuveitic cases (P = 0.02). Estimates of PCO incidence (95% confidence interval) in uveitic eyes derived from the Kaplan-Meier models were 38.5% (range, 28.9%-48.2%) at 1 year and 56% (range, 45.8%-66.3%) at 3 years, and estimates among nonuveitic eyes were 11.5% (range, 6.2%-16.8%) at 1 year and 38.4% (range, 29%-47.8%) at 3 years. These rates of PCO among patients with uveitis and those patients without uveitis differed significantly by the log-rank test (P = 0.004). However, after adjusting for the younger age of patients with uveitis, the rates of PCO were no longer statistically different. The apparent higher rate of PCO in patients with uveitis is primarily due to their younger age at the time of surgery. A moderately increased independent risk of PCO from uveitis cannot, however, be ruled out by this study.

Spontaneous Resolution of an Endocapsular Hematoma

To report a case of endocapsular hematoma that cleared spontaneously without intervention. We examined and followed up a 68-year-old man who developed an endocapsular hematoma 2 1/2 years after a standard extracapsular cataract extraction with posterior chamber intraocular lens implantation. After several months without intervention, the endocapsular hematoma completely resolved. Observation may be a rational treatment option in some patients with endocapsular hematoma.

Use of the anterior chamber maintainer in anterior segment surgery

Over a 12 month period, we used the anterior chamber maintainer (ACM) in cataract surgery in 258 patients; ages ranged from 15 to 95 years (mean 73 years). Surgery was performed using general or local anesthesia. The procedures were standard extracapsular cataract extraction (ECCE), mini-nuc ECCE, vectis extraction of the endonucleus, manual phacofragmentation, phacoemulsification, phacotrabeculectomy, repositioning the IOL, and anterior segment revision. We recorded our subjective assessment of the degree of anterior chamber (AC) maintenance and control of the position of the posterior capsule during surgery. We also kept clinical notes of the practical aspects of the procedures. The AC was well maintained in all patients throughout the surgery; posterior position of the posterior capsule was maintained during irrigation/aspiration. Five patients required the use of a viscoelastic agent at some stage. Our subjective assessment is that use of the ACM increased surgical control of the anterior chamber depth and position of the posterior capsule during surgery. Provided that it is used correctly, the ACM may offer increased safety during anterior segment surgery and require less use of viscoelastic agents.

Phacoemulsification-A Senior Surgeon's Learning Curve/COMMENT

We sought to prospectively document and evaluate the learning curve of an experienced extracapsular surgeon making a supervised transition from extracapsular cataract extraction (ECCE) to phacoemulsification. Over a period of 2 weeks, 51 phacoemulsification procedures using an endocapsular nucleofractis technique were performed by a single senior surgeon at the Christian Medical College in Vellore, India under the supervision of a visiting US expert with more than 15 years'experience in the technique. Vitreous loss occurred in seven eyes (six prior to the stage of cortical aspiration); failure of capsulorhexis necessitated conversion to standard ECCE in four. Injury to the inferior iris during phacoemulsification was cosmetically significant in three eyes

Synthesis of the literature on visual acuity and complications following cataract extraction with intraocular lens implantation. Cataract Patient Outcome Research Team.

To better define the effectiveness and risks of modern cataract surgery. Meta-analysis (formal systematic identification, selection, review, and synthesis) of published literature. Patients described in 90 studies published between 1979 and 1991 that addressed visual acuity (n = 17,390 eyes) or complications (n = 68,316 eyes) following standard extracapsular cataract extraction with posterior chamber intraocular lens implantation, phaco-emulsification with posterior chamber intraocular lens implantation, or intracapsular cataract extraction with flexible anterior chamber intraocular lens implantation. The proportion of eyes with postoperative Snellen visual acuity of 20/40 or better and the proportion of eyes with each of 18 complications. The pooled percentage of eyes (weighted by sample size) with postoperative visual acuity of 20/40 or better was 95.5% (95% confidence interval [CI], 95.1% to 95.9%) among eyes without preexisting ocular comorbidity and 89.7% (95% CI, 89.3% to 90.2%) for all eyes. The pooled percentage of eyes experiencing complications (weighted by sample size and, when pertinent, by quality score of the individual studies but not adjusted for variation in duration of follow-up) ranged from 0.13% for endophthalmitis to 19.7% for posterior capsule opacification. Pooled proportions of eyes with other complications were as follows: bullous keratopathy, 0.3%; intraocular lens malposition/dislocation, 1.1%; clinically apparent cystoid macular edema, 1.5%; and retinal detachment, 0.7%. Pooled results for postoperative Snellen visual acuity and most complications were similar for surgery performed via phacoemulsification vs standard extracapsular cataract extraction, although comparisons of the outcomes between these procedures should be interpreted with caution. The published literature indicates that modern cataract surgery yields excellent visual acuity and, although not free of complications, is a very safe procedure regardless of the extraction technique used.

Rigor of research methods in studies of the effectiveness and safety of cataract extraction with intraocular lens implantation. Cataract Patient Outcome Research Team.

To assess the rigor of research methods reported in studies of the safety or effectiveness of contemporary cataract surgery. Formal systematic identification of pertinent studies and critical appraisal of each study's research methods. From 6113 unique, potentially relevant citations that we identified, 90 original studies published between 1979 and 1991 that addressed visual acuity or complications following standard extracapsular cataract extraction with posterior chamber intraocular lens implantation, phacoemulsification with posterior chamber intraocular lens implantation, or intracapsular cataract extraction with flexible anterior chamber intraocular lens implantation. Strength of study design, performance, and reporting in 11 methodologic areas assessed with a standardized abstraction form by two reviewers masked to authors, their institutions, and the journal of publication. Results of reviews were tallied to produce an overall quality score (measure of rigor in research methods) for each study. The mean (+/- SD) quality score was 43.1 +/- 20.1 out of a maximum possible score of 100. Studies received intermediate scores on description of baseline ocular disease and low scores on descriptions of other characteristics of enrolled patients, standardization of outcome assessment and follow-up duration, and handling of patient attrition. Eighty-three studies (92%) lacked a comparison group. The rigor of research methods in studies varied by the journal of publication, did not improve over time, and was no greater for studies with larger vs smaller sample sizes. The rigor of research methods in studies of cataract surgery can be improved if more attention is paid to fundamental principles of study design, data analysis, and reporting.

Extracapsular Cryoextraction and Irrigation-Aspiration Procedure for Removal of Nuclear Sclerotic Lenses From Vitrectomized Eyes

Owing to the use of wide-angle observation systems 1,2 the lens can be preserved during the vast majority of pars plana vitrectomies. When such lenses later develop cataracts, they frequently exhibit nuclear sclerosis of such a degree that phacoemulsification would no longer be a safe procedure, even for experienced anterior-segment surgeons who are more and more comfortable emulsifying denser and denser lenses. The vitreous cavity of these eyes is filled with aqueous or silicone oil. This fact renders standard extracapsular cataract extraction with expression of the lens nucleus potentially hazardous because pressure on the globe may lead to collapse of the posterior segment in eyes filled with aqueous or to a localized rupture of the zonule and subsequent formation of a persistent pathway through which silicone oil can pass from the vitreous cavity into the anterior chamber. To avoid such complications, extracapsular cryoextraction, followed by an irrigation-aspiration procedure, has proven

Quantification of the reduction of glare disability after standard extracapsular cataract surgery

Glare disability is often cited as an indication for cataract extraction, but very little objective data exist showing improvement of glare disability following standard extracapsular cataract extraction with posterior chamber intraocular lens implantation. In a series of 25 patients we determined glare disability by the reduction in visual acuity with dim room lighting (baseline) and with full room lights; with the brightness acuity tester (BAT) on low, medium, and high; with the true vision analyzer (TVA) glare light. Glare disability was quantified by the difference between the log VA postoperatively and the log VA preoperatively. Glare disability with BAT medium was no different than that with bright room lights (P > .05). Glare disability with BAT high was greater than that with BAT medium (P < .01) but did not differ from that with TVA (P > .05). Glare disability was significantly reduced (P < .01) six weeks postoperatively as measured by all tests except BAT low. Cataract surgery can be expected to reduce glare disability as measured by these tests.

Infectious Endophthalmitis Following Sutureless Cataract Surgery-Reply

In Reply. —While a straw poll may be an initial way of gaining some insight into outcomes of a particular surgical event, it certainly cannot replace a properly designed prospective study. The potential problems with variable follow-up, nonrepresentiveness of patients, ascertainment of events, and similar issues emphasize the need for well-controlled research. The authors and their colleagues clearly have the patient volume to conduct a randomized trial of sutureless vs standard extracapsular cataract extraction to assess which approach provides better visual outcomes, fewer complications, and greater patient quality of life and satisfaction. A study of this nature would be of major value to the entire community.