Trachoma

Methodological quality of the review: Low confidence

Author: Anthony W Solomon, David CW Mabey

Geographical coverage: Not specified

Sector: Trachoma management

Sub-sector: See above

Equity focus: Not specified

Review type: Effectiveness review

Quantitative synthesis method: Narrative/thematic synthesis

Qualitative synthesis method: Not applicable

Background:

Active trachoma is the world’s leading infectious cause of blindness caused by chronic infection of the conjunctiva by chlamydia trachomatis. It is a disease of poverty, overcrowding and poor sanitation. The active disease affects mainly children, but adults are at increased risk of scarring.

Objectives:

The aim of this systematic review is to answer the following clinical questions: what are the effects of interventions to prevent scarring trachoma by reducing the prevalence of active trachoma? What are the effects of eyelid surgery for entropion and trichiasis?

Main findings:

In this study, 23 systematic reviews, randomised controlled trials (RCTs) or observational studies that met the inclusion criteria were included.

In this systematic review, authors present information relating to the effectiveness and safety of the following interventions: antibiotics, face washing (alone or alongside topical tetracycline), fly control (through the provision of pit latrines and using insecticide), health education and eyelid surgery (bilamellar tarsal rotation, or tarsal advance and rotation).

In relation to face-washing alone, there was no significant difference in the proportion of children with trachoma after three months between those who had washed their faces and those with no intervention. Authors noted that face washing plus face washing alongside topical antibiotics may be beneficial, but we don’t know whether face washing alone is effective. Fly control using insecticide alone, insecticide plus mass antibiotics, or by providing pit latrines, may reduce the risks of trachoma, but is unlikely to be a feasible large-scale approach.

Authors noted that evidence on oral or topical antibiotics was weak in terms of reducing the risk of active trachoma compared with placebo or with each other, as few comparable studies were found.

In addition, authors stated that eyelid rotation surgery with bilamellar tarsal rotation or tarsal advance and rotation may be effective at correcting entropion and trichiasis compared with other types of surgery. However, they also stated that they did not know whether posterior lamellar tarsal rotation plus azithromycin is more effective than posterior lamellar tarsal rotation alone at correcting entropion and trichiasis.

Methodology:

The following databases were searched for identifying relevant studies: MEDLINE, EMBASE, the Cochrane Library and other important databases up to January 2006. Additional searches were carried out using these websites: NHS Centre for Reviews and Dissemination (CRD) – for Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA), Turning Research into Practice (TRIP), and National Institute for Health and Clinical Excellence (NICE).

Abstracts of the studies retrieved from the initial search were assessed by an information specialist. Selected studies were then sent to the authors for additional assessment, using pre-determined criteria to identify relevant studies. Study design criteria for inclusion in this review were: published systematic reviews and RCTs in any language, at least single blinded, and containing more than 20 individuals, of whom at least 80% were followed up.

There was no minimum length of follow-up required to include studies. Authors excluded all studies described as “open”, “open label”, or not blinded unless blinding was impossible. Authors performed a GRADE evaluation of the quality of evidence for interventions included in this review.

Applicability/external validity:

Authors did not discuss applicability/external validity

Geographic focus:

All countries, not clear which countries

Summary of quality assessment:

Authors conducted a narrative synthesis of the findings, which seemed appropriate due to the vast differences of included studies, such as the difference in study population. However, this review had some important limitations. The methodology is not clear enough to ensure whether the screening of studies for inclusion and data extraction were conducted by two reviewers independently or not. Therefore, there is low confidence in the conclusions about the effects of this study.