Interventions for the treatment of trachoma: an overview of Cochrane systematic reviews

Methodological quality of the review: Medium confidence

Author: Lockwood C, Stern C

Geographical coverage: Egypt, The Gambia, United States, Pakistan, Guinea Conakry, Iran, Australia, India, Saudi Arabia, Taiwan and Tanzania.

Sector: Trachoma

Sub-sector: Treatment and prevention

Equity focus: Not specified

Review type: Effectiveness review

Quantitative synthesis method: Narrative/thematic synthesis

Qualitative synthesis method: Not applicable

Background: Trachoma is an infectious bacterial disease caused by chlamydia trachomatis. Infection with C. trachomatis results in characteristic changes to the inner surface of the eyelids that may lead to vision impairment and blindness. Globally, it is one of the leading causes of blindness.

Objectives: To identify the evidence from Cochrane systematic reviews regarding the treatment of trachoma, and to provide a brief and user-friendly front end for health professionals, researchers and policy makers.

Main findings:

In this review, authors included four Cochrane systematic reviews, including 28 trials. Interventions assessed by included studies were antibiotics for trachoma, environmental sanitary interventions and face-washing promotion for preventing active trachoma.

Participants in the included trials resided in a trachoma endemic area that had active trachoma in at least one eye. Geographical location of the included studies included: Egypt, The Gambia, United States, Pakistan, Guinea Conakry, Iran, Australia, India, Saudi Arabia, Taiwan and Tanzania. Overall, the quality of reviews included was high.

Authors reported that face washing plus topical tetracycline eye ointment gave no additional protective benefit against active trachoma when compared with topical tetracycline eye ointment alone. Nor was any benefit conferred in the presence of severe trachoma. Findings from the review reported that primary healthcare education was found to be effective in reducing the odds of active trachoma. Evidence of the benefits of insecticide spray or provision of latrines away from living areas was inconclusive for active trachoma. Authors noted that surgical interventions that involve full-thickness incision with tarsal rotation are more effective than alternate surgical procedures.

Overall, authors stated that primary healthcare education was found to be effective in reducing the odds of active trachoma. In addition, they stated that group assignment should be considered in future studies for environmental factors. The role of the use of topical antibiotics should also be considered in future studies.

Methodology:

In the review, authors included systematic reviews of randomised or quasi-randomised controlled trials, which addressed the treatment of trachoma. Authors included studies which included participants of any age that normally resided in areas where trachoma was prevalent and participants who were undergoing treatment. Types of interventions included those used for the treatment of trachoma.

The following primary outcome was specified for inclusion in this review: the number of participants with active trachoma at six, 12 or greater than 12 months post-treatment allocation (age group as reported in trials) where active trachoma was indicated by scale measures of trachoma follicular inflammation (TF), trachoma intense inflammation (TI) or both, in the Thylefors scale; or any other grade for P or F in the WHO or Dawson scales.

The only database searched was the Cochrane Database of Systematic Reviews (CDSR) via the Cochrane Library (November 2012, Issue 11) using the search term ‘trachoma’ as title, abstract or keyword. Two reviewers independently identified the relevant articles and extracted the data. The quality assessment of included articles was conducted using specific criteria. The extracted data was descriptively analysed.

Applicability/external validity:

The authors mentioned that “the applicability of evidence was rarely addressed”.

Geographic focus:

Authors did not restrict the search to a specific context. Authors included studies from locations where trachoma was prevalent or high-risk. Although findings may be relevant to low and middle-income countries, authors did not discuss findings specifically to these settings.

Summary of quality assessment:

Authors used appropriate methods to select studies for inclusion in the review, extract data of included studies and critically appraise included studies. Authors appropriately analysed the findings of included studies. However, authors did not conduct a thorough search of the literature to ensure all studies were included. Therefore, medium confidence was attributed in the conclusions about the effects of this study.