Objectives:

Cataract and glaucoma are ocular diseases that often coexist, with prevalences over age 40 of 20 percent and two percent, respectively. There is no agreement concerning their optimal management when coexistent. We prepared this evidence report to: identify the important questions pertinent to surgical treatment of coexisting cataract and glaucoma; assess the quality and content of evidence on surgical treatment of coexisting cataract and glaucoma; and inform clinical practitioners and identify areas for future research.

Search Strategy:

The searches were conducted on publications from 1980 to April 2000 using two electronic databases, PubMed and CENTRAL. Text words and Medical Subject Heading (MeSH) search terms used included (“cataract” and “glaucoma”) and (“surgery” or “filtering surgery” or “cataract extraction” or “sclerostomy” or “trabeculectomy” or “phacoemulsification”). We included variants of “randomized controlled trials” in the search as well as “case report” and “case series”. The electronic searches were augmented by a hand search of primary journals.

Selection Criteria:

Two individuals independently reviewed each abstract. The exclusion criteria were: no human data, lack of adults, lack of original data, failure to address open-angle or primary angle- closure glaucoma, not a controlled trial nor a case series greater than or equal to 100 eyes, only addressing intracapsular surgery, only addressing full-thickness procedures, was a meeting abstract, and not in English.

Data Collection and Analysis:

Two data abstraction forms were developed. The 25 question quality assessment form was divided into the following categories: representativeness, bias and confounding, description of therapy, outcomes and followup, and statistical quality and interpretation. A content assessment form was developed through an iterative process.

Each article was reviewed by two reviewers, at least one trained in research methodology and at least one trained in ophthalmology. Quality scores for each controlled trial and cohort study were tabulated.

For each study question one member of the analysis team summarized the extracted data and formulated a conclusion about the answer to each question. For each conclusion, the entire study team assigned an evidence grade of A (strong), B (intermediate), C (weak), or I (insufficient).

Main Results:

There was strong evidence that glaucoma surgery is associated with an increased risk of postoperative cataract; moderately strong evidence that mitomycin-C, but not 5-fluorouracil is beneficial in combined procedures, limbus- and fornix-based conjunctival incisions are equally effective for lowering IOP, and the size of the phacoemulsification incision is not important; and weak evidence that combined procedures using phacoemulsification rather than nuclear expression result in lower long-term IOP, as do two-site compared to one-site combined procedures.

Limitations of the literature included lack of optic nerve and visual field data, lack of objective description of the ocular lens, inconclusive information on complications, lack of patient preference and quality of life data, and limited followup in many studies.

Conclusions:

The literature does not point to one optimal strategy for controlling IOP in patients with coexisting cataract and glaucoma needing surgery. Therefore, there is a continued need for high quality studies with greater duration and more information on optic nerve and visual field findings.