Systematic literature review for clinical practice guideline development

The purpose of this paper was to evaluate the quality and scope of the published literature on functional impairment due to cataract in adults as reviewed for the Agency for Health Care Policy and Research Clinical Practice Guideline. We examined the method of literature retrieved and analysis performed in the course of development of literature-based recommendations for the guideline panel. To collect data, we reviewed the process of literature acquisition and identification and the quality assessments made by reviewers of 14 individual topics composed of 77 issues related to the guideline. We collated this information to provide an assessment of the quality and scope of the relevant literature. Less than 4% (310) of the approximately 8,000 articles initially identified as potentially relevant to the guideline were ultimately used. The majority covered three topics (surgery and complication, 100; Nd:YAG capsulotomy, 77; and potential vision testing, 40). Three other topics--indications for surgery, preoperative medical evaluation, and rehabilitation--were devoid of articles meeting inclusion criteria. For 43 issues, there was no identifiable relevant literature. With few exceptions, the quality of the literature was rated fair to poor owing to major flaws in experimental design. Case series (256 reports) of one type or another accounted for the majority of the included literature. There were 17 random controlled trials. This review revealed a sparse and generally low-quality literature relevant to the management of functional impairment due to cataract, despite a relatively large data base in reputable peer-reviewed journals.

Prospective audit comparing ambulatory day surgery with inpatient surgery for treating cataracts

OBJECTIVES

To compare the cost effectiveness and safety of inpatient cataract surgery (with one night in hospital postoperatively) with ambulatory day case surgery under local anaesthesia.

DESIGN

Prospective study of patients receiving inpatient (group 1) or day case (group 2) surgery.

SETTING

One ophthalmic surgical firm.

PATIENTS

100 patients in each group, excluding those with coexisting ocular conditions, contraindications to local or request for general anaesthesia, ill health, or lack of agreed minimum social care; four patients died during follow up.

INTERVENTIONS

Envelope method and implantation of the posterior chamber lens into the capsular sac in both groups.

MAIN MEASURES

Perioperative complications, operating and turnover times, visual outcome at three to six days and 10 weeks to six months after operation, patient satisfaction (according to self administered questionnaire) at three to six days, and total costs (1989 salaries) for both groups.

RESULTS

Patients in both groups did not differ significantly in age or sex, perioperative complications, visual outcome (6/9 or better in 78 patients in group 1 and 75 in group 2 at one month after operation and 6/12 or better in 92/98 in group 1, 90/98 in group 2 at final follow up), or patient satisfaction. The mean total cost per patient for group 1 patients was 365.99 pounds and for group 2, 221.62 pounds.

CONCLUSIONS

Day case surgery for cataract is safe and more cost effective.

IMPLICATIONS

Day case surgery should be recommended to increase availability of cataract surgery and thereby improve quality of life for more patients.

Medicare Peer Review Organization preprocedure review criteria. An analysis of criteria for three procedures

The Medicare Peer Review Organization (PRO) program includes preprocedure review using explicit criteria to assess the appropriateness of specific procedures. This study evaluates the variability in the PRO preprocedure criteria for the three procedures most frequently reviewed by PROs: carotid endarterectomy, cataract removal, and cardiac pacemaker implants. In August 1989, the PRO review criteria were received from the Health Care Financing Administration. To provide a reference point for reviewing the PRO criteria, national practice guidelines for these three procedures were identified. Wide variability was demonstrated in the PRO procedure-specific carotid endarterectomy and cataract removal review criteria among PROs, and the criteria differed significantly from the identified practice guidelines. The criteria for cardiac pacemaker implants were somewhat less variable, and were based, to varying degrees, on practice guidelines developed by the American College of Cardiology (ACC). Greater attention is needed to improve the development of review criteria, including the use of relevant practice guidelines, to ensure that review criteria are optimal.

Phacoemulsification systems

Our objectives in conducting this evaluation were to present an overview of a basic phacoemulsification system and its components, to describe the phacoemulsification procedure within the context of the operating principles of the system's components, and to compare two manufacturers' products. Specifications for additional phacoemulsification systems are available in the November 1989 edition of ECRI's Hospital Product Comparison System. Both of the evaluated systems enable a surgeon to perform a complete cataract extraction procedure by phacoemulsification. We rated both units Acceptable. In selecting a unit, users should consider performance, safety, human factors design, and manufacturer training and support. Although list prices vary widely among available systems, cost factors should not override clinical performance and safety requirements. While we measured certain engineering parameters, such as stroke length and ultrasound (US) output forces exerted on a medium, we stress that the results of these tests do not provide enough information to predict clinical performance. Clinical performance of phacoemulsification systems can be determined only by the experience of the clinicians who use them. Clinicians should review our evaluation thoroughly before making a purchasing decision. The information we present is useful for purchasing the evaluated or other available models because our criteria will guide users in assessing all components, and our findings and discussion on some aspects are common to many available systems (e.g., type of pump, irrigation and aspiration [I/A] characteristics). The in-depth clinical and technical information will help users to better understand principles, thereby helping them to better define their needs. Although we discovered a number of problems with the evaluated models, users should not assume that similar or other problems do not exist with systems that we did not evaluate. The willingness of manufacturers to cooperate in our studies and the knowledge they gain through participating may lead to the development of better products.

[Comparison of phacoemulsification and manual extracapsular extraction of the lens]

In a prospective study, 60 patients have been operated on for cataract either with phacoemulsification or with manual extracapsular extraction of the lens. All the patients received the same type of PMMA intraocular lens. Visual results and incidence of angiographic cystoïd macular edema were similar in both groups. The mean endothelial cell loss was 10.7% with phacoemulsification and 7% with manual extracapsular extraction.

[Pars plana phacoemulsification. Technics, indications and results]

Pars plana phacoemulsification allows cataract extraction through a 3 mm posterior sclerotomy. The indications of these technics are the combined cataract-vitrectomy, the cataracts on vitrectomised eyes and cataracts on eyes filled with silicone oil. The alteration of corneal endothelium is very reduced with the endocapsular pars plana phacoemulsification. After the emulsification, the capsular bag is extracted with a microforceps through the pars plana. It is also possible to save the anterior capsule to reduce corneal alteration during endocular surgery. We present the indications and the advantages of these technics.

Drg-39

The development of extracapsular cataract extraction with insertion of an intraocular lens has undoubtedly been one of medical science's greatest advances in the rehabilitation of vision. It has also lead to vigorous debates within and without the profession about the efficacy of the procedure and its cost-benefit ratio. Criticism directed toward cataract surgery, both by those in the medical profession and those in governmental agencies, must be addressed if ophthalmologists are going to continue to be able to meet the needs of their patients.

Extracapsular cataract extraction: an analysis of 240 operations in dogs

A total of 240 extracapsular cataract extractions were performed on 214 dogs at the University of Illinois between 1968 and 1980. Overall success of the surgery, defined as restoration of functional vision for at least 6 weeks after surgery, was 79%. The success rates, on the basis of various parameters, were compared with the following results. The greater the number of years experience each surgeon had, the greater the surgical success rate. In dogs in which a second eye was operated on, the overall success rate on the second eye was approximately 20% less than that for the study as a whole. There was a significant difference in success rates between surgery on congenital and juvenile cataracts when compared with surgery on diabetic and senile cataracts, the first being 15% higher than the second. The success rate was 18% less for lensectomy with concurrent iridectomy than for lensectomy without iridectomy. There was no significant difference in success rates among the 3 procedures for extracapsular extraction used in this study, nor among the various breeds studied. There was no significant difference in the success rate of surgeries on the left eye, compared with surgeries on the right eye.

Educating the implant surgeon

Intraocular lens implantation is a remarkable advance in the visual rehabilitation of the aphakic patient. The success of implantation is linked to the quality of the cataract surgery. Methods for refined cataract extraction include microsurgery and the use of newer instrumentation. The practiced cataract surgeon and the surgeon in training must master these techniques before implantation is undertaken. Intraocular lens surgery must likewise follow a logical progression from attendance and participation at practical courses to assisting at surgery, to implanting with an experienced intraocular lens surgeon present to monitor and assist, if necessary. As with any new technique, a variety of ancillary advances develop which also require understanding and expertise on the part of the surgeon. These affect judgmental decisions which become as important as the actual surgery. The field of implantation has continued to grow by providing new information on a variety of subjects. The novice implant surgeon, as well as the experienced implant surgeon, must constantly be aware of these advances and strive to master the techniques of this exciting and valuable field.

[Does cryoextraction really improve cataract-surgery? (AUTHOR'S TRANSL)]

In the past 8 years 1058 out 3970 cataract operations, that is 26.7%, were performed with different cryoextractors. There was an increase in frequency from 41 operations in 1967 to 410 in 1974. Since March 1974 the cryoextractor from the Opticon Company was used exclusively. The experiences with the cryoextractor are reported and the results compared with the extraction by aspiration.