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BMJ Clin Evid. 2007; 2007: 0706.
Published online 2007 December 6.
PMCID: PMC2943797

Trachoma

Abstract

Introduction

Active trachoma is caused by chronic infection of the conjunctiva by Chlamydia trachomatis, and is the world's leading infectious cause of blindness. Infection can lead to scarring of the tarsal conjunctiva, inversion of the eyelashes so that they abrade the cornea (trichiasis), and corneal opacity, leading to blindness. Trachoma is a disease of poverty, overcrowding, and poor sanitation. Active disease affects mainly children, but adults are at increased risk of scarring.

Methods and outcomes

We conducted a systematic review and aimed 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 eye lid surgery for entropion and trichiasis? We searched: Medline, Embase, The Cochrane Library and other important databases up to January 2006 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

Results

We found 23 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

Conclusions

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

Key Points

Active trachoma is caused by chronic infection of the conjunctiva by Chlamydia trachomatis, and is the world's leading infectious cause of blindness.

  • Infection can lead to scarring of the tarsal conjunctiva, shortening and inversion of the upper eyelid (entropion) and scarring of the eye by eyelashes (trichiasis), leading to blindness.
  • Trachoma is a disease of poverty, overcrowding, and poor sanitation. Active disease mainly affects children, but adults are at increased risk of scarring.

Public health interventions to improve hygiene may reduce the risks of developing trachoma, but studies have given conflicting results.

We don't know whether oral or topical antibiotics reduce the risk of active trachoma compared with placebo or with each other, as few comparable studies have been found.

Lid 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.

We don't know whether posterior lamellar tarsal rotation plus azithromycin is more effective than posterior lamellar tarsal rotation alone at correcting entropion and trichiasis.

Clinical context

About this condition

Definition

Active trachoma is chronic inflammation of the conjunctiva caused by infection with Chlamydia trachomatis. The World Health Organization simplified trachoma grading scheme defines active trachoma as TF and/or TI, where TF (trachomatous inflammation — follicular) is the presence of five or more follicles in the central part of the upper tarsal conjunctiva, each at least 0.5 mm in diameter, and TI (trachomatous inflammation — intense) is pronounced inflammatory thickening of the upper tarsal conjunctiva that obscures more than half of the normal deep vessels.[1] Cicatricial trachoma is caused by repeated infection with C trachomatis; it includes the presence of visible scars on the tarsal conjunctiva (trachomatous scarring), shortening and inversion of the upper eye lid (entropion), and malposition of the lashes so that they abrade the eye (trichiasis). Trachomatous scarring can be present without entropion/trichiasis, but if entropion/trichiasis is present because of trachoma, there will be scarring. Trachoma blindness results from corneal opacification, which occurs because of the mechanical trauma wrought by entropion/trichiasis. Diagnosis of trachoma is by clinical examination, using the criteria set out in either the modified WHO grading system[2] or the WHO simplified grading system.[1] The simplified grading system is now the most commonly employed.

Incidence/ Prevalence

Trachoma is the world's leading cause of infectious blindness.[3] Globally, active trachoma affects an estimated 84 million people, most of them children. About 7.6 million people are blind or at risk of blindness as a consequence.[4] Trachoma is a disease of poverty, regardless of geographical region. Cicatricial trachoma is prevalent in large regions of Africa, the Middle East, Asia, and Aboriginal communities in Australia, and there are also small foci in Central and South America.[3] In areas where trachoma is constantly present at high prevalence, active disease is found in more than 50% of preschool children, and may have a prevalence as high as 60–90%,[5] and as many as 75% of women and 50% of men aged over 45 years may show signs of scarring disease.[6] The prevalence of active trachoma decreases with increasing age.[5] Although similar prevalences of active disease are observed in boys and girls, the later sequelae of trichiasis, entropion, and corneal opacification are usually more common in women than men.[5]

Aetiology/ Risk factors

Active trachoma is associated with youth, poor access to water and sanitation, and close contact between people. Discharge from the eyes and nose may facilitate transmission of ocular C trachomatis infection.[7] Sharing a bedroom with someone who has active trachoma is a risk factor for infection.[8] The density of eye-seeking flies in a community is associated with active trachoma.[9] [10] Flies important to trachoma transmission lay their eggs on human faeces lying exposed on the soil, suggesting that access to improved sanitation might help control trachoma.[11] [12]

Prognosis

Corneal damage from trachoma is caused by multiple processes. Scarring trachoma damages glandular structures and may cause an inadequate tear film; a dry eye may be more susceptible to damage from inturned lashes and superadded infection by other bacteria and fungi, leading to corneal opacification.

Aims of intervention

To prevent or cure active trachoma; to reduce the rate of progression to scarring trachoma; to relieve entropion and trichiasis; with minimal adverse effects.

Outcomes

Prevalence of active trachoma; laboratory evidence of C trachomatis infection; eyelid position; degree of entropion/trichiasis, adverse effects of treatment. RCTs conducted before 1981 may use definitions of trachoma that differ from the present World Health Organization definitions.[1] [2]

Methods

BMJ Clinical Evidence search and appraisal January 2007. The following databases were used to identify studies for this systematic review: Medline 1966 to January 2007, Embase 1980 to January 2007, and The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials 2006, Issue 4. 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. We excluded all studies described as “open”, “open label”, or not blinded unless blinding was impossible. We use a regular surveillance protocol to capture harms alerts from organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA), which are added to the reviews as required. We have performed a GRADE evaluation of the quality of evidence for interventions included in this review (see table ).

Table 1
GRADE evaluation of interventions for trachoma

Glossary

Bilamellar tarsal rotation
The upper lid is cut full thickness horizontally in a line parallel and 3 mm from the eyelid margin and running from just lateral to the lacrimal punctum to the lateral canthus. Everting sutures are then placed through all layers of the lid to prevent the margin from turning inwards.
Entropion
Inversion of the eye lid.
Eversion splinting
The lid margin is split posterior to the lashes, the eversion of the anterior section is maintained by sutures tied over a roll of paraffin gauze.
Low-quality evidence
Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Major trichiasis
Lid closure complete; six or more lashes in contact with eyeball.
Minor trichiasis
Lid closure complete; one to five lashes in contact with eyeball.
Moderate-quality evidence
Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Phthisis bulbi
A disorganised, shrunken eye that does not perceive light.
Tarsal advance
The lid margin is split posterior to the lashes. The skin, lashes, and orbicularis are freed from the tarsal plate and retracted away from the cornea and are sutured back on to the tarsal plate, leaving a bare area of tarsus to act as the lid margin.
Tarsal advance and rotation
The upper lid is everted over a speculum. The tarsal plate is fractured parallel to, and 3 mm from, the lid margin. In this operation the skin and orbicularis are not cut. The short portion of tarsal plate attached to the lid margin is then rotated through 180° and sutured into place to form the new lid margin.
Tarsal grooving
A wedge of skin, orbicularis, and tarsus is removed parallel to the lid margin. Sutures through all layers act to evert the lid margin.
Trichiasis
The misdirection of lashes towards the eyeball.
Very low-quality evidence
Any estimate of effect is very uncertain.

Notes

Disclaimer

The information contained in this publication is intended for medical professionals. Categories presented in Clinical Evidence indicate a judgement about the strength of the evidence available to our contributors prior to publication and the relevant importance of benefit and harms. We rely on our contributors to confirm the accuracy of the information presented and to adhere to describe accepted practices. Readers should be aware that professionals in the field may have different opinions. Because of this and regular advances in medical research we strongly recommend that readers' independently verify specified treatments and drugs including manufacturers' guidance. Also, the categories do not indicate whether a particular treatment is generally appropriate or whether it is suitable for a particular individual. Ultimately it is the readers' responsibility to make their own professional judgements, so to appropriately advise and treat their patients. To the fullest extent permitted by law, BMJ Publishing Group Limited and its editors are not responsible for any losses, injury or damage caused to any person or property (including under contract, by negligence, products liability or otherwise) whether they be direct or indirect, special, incidental or consequential, resulting from the application of the information in this publication.

Contributor Information

Anthony Solomon, London School of Hygiene & Tropical Medicine, London, UK.

David Mabey, London School of Hygiene & Tropical Medicine, London, UK.

References

1. Thylefors B, Dawson CR, Jones BR, et al. A simple system for the assessment of trachoma and its complications. Bull World Health Organ 1987;65:477–483. [PubMed]
2. Dawson CR, Jones BR, Tarizzo ML. Guide to trachoma control in programmes for the prevention of blindness. Geneva: World Health Organization; Albany, NY: WHO Publications Centre USA [Distributor], 1981.
3. Resnikoff S, Pascolini D, Etya′ale D, et al. Global data on visual impairment in the year 2002. Bull World Health Organ 2004;82:844–851. [PubMed]
4. Mariotti SP. New steps toward eliminating blinding trachoma. N Engl J Med 2004;351:2004–2007. [PubMed]
5. West SK, Munoz B, Turner VM, et al. The epidemiology of trachoma in central Tanzania. Int J Epidemiol 1991;20:1088–1092. [PubMed]
6. Courtright P, Sheppard J, Schachter J, et al. Trachoma and blindness in the Nile Delta: current patterns and projections for the future in the rural Egyptian population. Br J Ophthalmol 1989;73:536–540. [PMC free article] [PubMed]
7. Bobo L, Munoz B, Viscidi R, et al. Diagnosis of Chlamydia trachomatis eye infection in Tanzania by polymerase chain reaction/enzyme immunoassay. Lancet 1991;338:847–850. [PubMed]
8. Bailey R, Osmond C, Mabey DC, et al. Analysis of the household pattern of trachoma in a Gambian village using a Monte Carlo simulation procedure. Int J Epidemiol 1989;18:944–951. [PubMed]
9. Emerson PM, Lindsay SW, Walraven GE, et al. Effect of fly control on trachoma and diarrhoea. Lancet 1999;353:1401–1403. [PubMed]
10. Emerson PM, Lindsay SW, Alexander N, et al. Role of flies and provision of latrines in trachoma control: cluster-randomised controlled trial. Lancet 2004;363:1093–1098. [PubMed]
11. Emerson PM, Bailey RL, Mahdi OS, et al. Transmission ecology of the fly Musca sorbens, a putative vector of trachoma. Trans R Soc Trop Med Hyg 2000;94:28–32. [PubMed]
12. Emerson PM, Bailey RL, Walraven GE, et al. Human and other faeces as breeding media of the trachoma vector Musca sorbens. Med Vet Entomol 2001;15:314–320. [PubMed]
13. Ejere HO, Alhassan MB, Rabiu M. Face washing promotion for preventing active trachoma. In: The Cochrane Library, Issue 12, 2014. Chichester, UK: John Wiley & Sons, Ltd. Search date 2011.
14. Peach H, Piper S, Devanesen D, et al. Northern Territory Trachoma Control and Eye Health Committee's randomised controlled trial of the effect of eye drops and eye washing on follicular trachoma among Aboriginal children. Report of the Northern Territory Trachoma Control and Eye Health Committee Incorporated. Menzies School of Health Research (Australia), 1987:1–33.
15. Peach H, Piper S, Devanesen D, et al. Trial of antibiotic drops for the prevention of trachoma in school-age Aboriginal children. Annual Report, Menzies School of Health Research 1986–87. Menzies School of Health Research (Australia), 1987:74–76.
16. West S, Muñoz B, Lynch M, et al. Impact of face washing on trachoma in Kongwa, Tanzania. Lancet 1995;345:155–158. [PubMed]
17. Rabiu M, Alhassan M, Ejere HO, et al. Environmental sanitary interventions for preventing active trachoma. In: The Cochrane Library, Issue 12, 2014. Chichester, UK: John Wiley & Sons, Ltd. Search date 2011.
18. Mabey D, Fraser-Hurt N. Antibiotics for trachoma. In: The Cochrane Library, Issue 4, 2006. Chichester, UK: John Wiley & Sons, Ltd. Search date 2005; primary sources Medline, Embase, Cinahl, Science Citation Index, Cochrane Controlled Trials Register, and personal contacts.
19. Attiah MA, el Kohly AM. Clinical assessment of the comparative effect of terramycin and GS 2989 in the mass treatment of trachoma. Rev Int Trach Pathol Ocul Trop Subtrop Sante Publique 1973;50:11–20. [PubMed]
20. Darougar S, Jones BR, Viswalingam N, et al. Family-based suppressive intermittent therapy of hyperendemic trachoma with topical oxytetracycline or oral doxycycline. Br J Ophthalmol 1980;64:291–295. [PMC free article] [PubMed]
21. Dawson CR, Hanna L, Wood TR, et al. Controlled trials with trisulphapyrimidines in the treatment of chronic trachoma. J Infect Dis 1969;119:581–590. [PubMed]
22. Foster SO, Powers DK, Thygeson P. Trachoma therapy: a controlled study. Am J Ophthalmol 1966;61:451–455. [PubMed]
23. Hoshiwara I, Ostler HB, Hanna L, et al. Doxycycline treatment of chronic trachoma. JAMA 1973;224:220–223. [PubMed]
24. Shukla BR, Nema HV, Mathur JS, et al. Gantrisin and madribon in trachoma. Br J Ophthalmol 1966;50:218–221. [PMC free article] [PubMed]
25. Woolridge RL, Cheng KH, Chang IH, et al. Failure of trachoma treatment with ophthalmic antibiotics and systemic sulphonamides used alone or in combination with trachoma vaccine. Am J Ophthalmol 1967;63(suppl):1577–1586. [PubMed]
26. Bowman RJC, Sillah A, Van Dehn C, et al. Operational comparison of single-dose azithromycin and topical tetracycline for trachoma. Invest Ophthalmol Vis Sci 2000;41:4074–4079. [PubMed]
27. Dawson CR, Schachter J, Sallam S, et al. A comparison of oral azithromycin with topical oxytetracycline/polymyxin for the treatment of trachoma in children. Clin Infect Dis 1997;24:363–368. [PubMed]
28. Schachter J, West SK, Mabey D, et al. Azithromycin in control of trachoma. Lancet 1999;354:630–635. [PubMed]
29. Tabbara KF, Abu el Asrar A, al Omar O, et al. Single-dose azithromycin in the treatment of trachoma. A randomized, controlled study. Ophthalmology 1996;103:842–846. [PubMed]
30. Yorston D, Mabey D, Hatt S, et al. Interventions for trachoma trichiasis. In: The Cochrane Library, Issue 4, 2006. Chichester, UK: John Wiley & Sons, Ltd. Search date 2006.
31. Reacher MH, Huber MJE, Canagaratnam R, et al. A trial of surgery for trichiasis of the upper lid from trachoma. Br J Ophthalmol 1990;74:109–113. [PMC free article] [PubMed]
32. Reacher MH, Munoz B, Alghassany A, et al. A controlled trial of surgery for trachomatous trichiasis of the upper lid. Arch Ophthalmol 1992;110:667–674. [PubMed]
33. Adamu Y, Alemayehu W. A randomized clinical trial of the success rates of bilamellar tarsal rotation and tarsotomy for upper eyelid trachomatous trichiasis. Ethiop Med J 2002;40:107–114. [PubMed]
34. Reacher MH, Taylor HR. The management of trachomatous trichiasis. Rev Int Trach Pathol Ocul Trop Subtrop Sante Publique 1990;67:233–262. [PubMed]
35. Bowman RJ, Soma OS, Alexander N, et al. Should trichiasis surgery be offered in the village? A community randomised trial of village vs. health centre-based surgery. Trop Med Int Health 2000;5:528–533. [PubMed]
36. Burton MJ, Kinteh F, Jallow O, et al. A randomised controlled trial of azithromycin following surgery for trachomatous trichiasis in the Gambia. Br J Ophthalmol 2005;89:1282–1288. [PMC free article] [PubMed]
37. Alemayehu W, Melese M, Bejiga A, et al. Surgery for trichiasis by ophthalmologists versus integrated eye care workers: a randomized trial. Ophthalmology 2004;111:578–584. [PubMed]
2007; 2007: 0706.
Published online 2007 December 6.

Face washing alone

Summary

INCIDENCE RATES Compared with control: Face washing alone is no more effective at 3 months at reducing the prevalence of trachoma in children compared with no face washing ( moderate-quality evidence ).

Benefits

Face washing versus no intervention:

We found one systematic review (search date 2004)[13] on the effect of face-washing promotion, which identified one RCT (reported in two publications).[14] [15] The RCT (1143 children in 36 communities) compared three groups: daily face washing alone, daily face washing plus daily topical tetracycline (as drops for 1 week each month), and no intervention.[14] [15] The RCT found no significant difference in the proportion of children with trachoma after 3 months between face washing alone and no intervention (191/246 [78%] with face washing alone v 160/211 [76%] with no intervention; regression analysis, P greater than 0.05).[14] [15] Face washing was performed by a teacher. Trachoma was defined as the presence of at least one follicle or some papillae on the upper tarsal plate (this study predated publication of the present World Health Organization trachoma grading schemes — see comment below). All of the children recruited to the trial had signs of trachoma at baseline according to this definition. Losses to follow-up were included in the analysis as being trachoma positive.

Face washing versus antibiotics:

The review[13] identified two RCTs comparing face washing plus health education versus antibiotics. It was not possible to extract data relating to the face-washing and health-education interventions separately.

Harms

The systematic review gave no information about harms.[13]

Comment

That fact that the RCT did not use the current World Health Organization trachoma grading scheme to define its outcome measures may limit the applicability of its results.[14] [15]

Substantive changes

No new evidence

2007; 2007: 0706.
Published online 2007 December 6.

Face washing plus antibiotics

Summary

INCIDENCE RATES Compared with control: Face washing plus topical tetracycline is more effective at 3 months at reducing the prevalence of trachoma in children compared with no face washing ( moderate-quality evidence ). Promotion of face washing plus topical tetracycline compared with tetracycline alone: Promotion of face washing plus topical tetracycline may be more effective at reducing the risk of "severe trachoma" at 1 year, but may be no more effective at reducing the risk of "any trachoma" compared with topical tetracycline alone ( low-quality evidence ).

Benefits

Face washing plus topical tetracycline versus no intervention:

We found one systematic review (search date 2004)[13] on the effect of face-washing promotion, which identified one RCT (1143 children in 36 communities).[14] [15] The RCT compared three groups: daily face washing alone, daily face washing plus daily topical tetracycline (as drops for 1 week each month), and no intervention.[14] [15] It found that face washing plus tetracycline drops significantly reduced the proportion of children with trachoma after 3 months compared with no intervention (215/312 [69%] with face washing plus topical tetracycline v 160/211 [76%] with no intervention; regression analysis, P less than 0.05).[14] [15]Face washing was performed by a teacher. Trachoma was defined as the presence of at least one follicle or some papillae on the upper tarsal plate (this study predates publication of the present World Health Organization trachoma grading schemes — see comment below). All of the children recruited to the trial had signs of trachoma at baseline according to this definition. Losses to follow-up were included in the analysis as being trachoma positive.

Promotion of face washing plus topical tetracycline versus topical tetracycline alone:

We found one systematic review (search date 2004)[13] on the effect of face-washing promotion, which identified one cluster RCT (1417 children aged 1–7 years in 6 villages; see comment below on cluster randomisation).[16] The RCT compared 1 month's intensive promotion of face washing plus 30 days of daily topical tetracycline (ointment) versus 30 days of daily topical tetracycline alone.[16] It found that promoting face washing plus topical tetracycline significantly reduced the risk of “severe trachoma” after 1 year compared with topical tetracycline alone (OR for “severe trachoma” 0.62, 95% CI 0.40 to 0.97). “Severe trachoma” was defined, uniquely in the study, as the presence of 15 or more follicles, or the presence of inflammation that obscured all the deep tarsal vessels. It found that the reduction in risk of “any trachoma” was not significant between groups (any trachoma, defined as follicular trachoma [TF] with or without inflammation: OR 0.81, 95% CI 0.42 to 1.59).[16] The RCT found that, when all participants from intervention and control villages were pooled, children who had a sustained clean face were significantly less likely to have “any trachoma” than those who never had a clean face or who had a clean face at only one follow-up visit during the study period (OR 0.58, 95% CI 0.47 to 0.72).[16]

Harms

The review gave no information about harms.[13]

Comment

That neither RCT used the current World Health Organization trachoma grading scheme to define their outcome measures may limit the applicability of their results.[14] [15] [16]Cluster randomisation in the RCT comparing face washing plus topical tetracycline versus topical tetracycline alone limits the power to detect differences between groups, and the interpretation of results for individual children.[16]

Substantive changes

No new evidence

2007; 2007: 0706.
Published online 2007 December 6.

Fly control through the provision of pit latrines

Summary

INCIDENCE RATES Compared with control: Fly control through the provision of improved household pit latrines may be no more effective at reducing the prevalence of active trachoma compared with using existing facilities — mainly no or local latrines ( low-quality evidence ).

Benefits

Fly control through the provision of household pit latrines

:

We found one systematic review (search date 2005)[17] on the effect of environmental sanitary interventions, which identified one RCT. [10]The RCT compared seven sets of three village clusters (7080 people in 21 village clusters) with successive sets recruited 2 months apart to cover all different seasons. In each set of three village clusters, one cluster was randomised to receive household pit latrines, one to receive permethrin spraying, and one to receive no intervention (control).[10] Improved household pit latrines (non-ventilated) were provided on the basis of one per household or per 20 people — whichever allowed for the most latrines — whereas the control group used existing facilities (households: 97% with no latrine or local latrine).[10]The RCT found no significant difference in active trachoma prevalence between the provision of latrines and control (mean change compared with control clusters: –30%, 95% CI –81% to +22%; P = 0.210).[10]

Harms

The review gave no information about harms. [17]

Comment

Cluster randomisation limits the power to detect differences between groups, and the interpretation of results for individuals.[10] The review found that concealment of allocation was inadequate in the RCT, and also noted that the allocation of the villages to intervention was quasi-randomised, as the villages were said to have been “arbitrarily allocated”.[17]

Substantive changes

No new evidence

2007; 2007: 0706.
Published online 2007 December 6.

Fly control using insecticide alone

Summary

INCIDENCE RATES Compared with control: Fly control using insecticides (deltamethrin, and permethrin) may be more effective at reducing prevalence of active trachoma compared with control, but this short-term beneficial effect may be neither cost-effective nor environmentally acceptable on a large scale ( very low-quality evidence ).

Benefits

Fly control using insecticide versus no intervention:

We found one systematic review (search date 2005)[17] on the effect of environmental sanitary interventions, which identified two RCTs.[9] [10]The first RCT identified by the review[17] was a pilot study comparing spraying of deltamethrin for 3 months versus no intervention in two pairs of villages (any age, screened at 3 months: 484 people in 2 villages with intervention, 440 people in 2 villages with no intervention).[9] One pair of villages received deltamethrin or no intervention in the wet season, and the other pair received deltamethrin or no intervention in the dry season. The pilot study found that spraying of deltamethrin significantly reduced the number of new cases of trachoma (World Health Organization classification) after 3 months compared with no intervention (wet and dry season combined, absolute numbers not reported; RR 0.25, 95% CI 0.09 to 0.64).[9]The second RCT identified by the review compared seven sets of three village clusters (7080 people in 21 village clusters) with successive sets recruited 2 months apart to cover all different seasons. In each set of three village clusters, one cluster was randomised to receive permethrin spraying, one to receive household pit latrines, and one to receive no intervention (control).[10] The RCT found that permethrin spraying was associated with a significant reduction in the prevalence of active trachoma compared with control (mean change in village cluster prevalence compared with control clusters: –56%, 95% CI –19% to –93%; P = 0.01).[10]

Harms

Fly control using insecticide versus no intervention:

The review reported on adverse effects from only one RCT.[17] It reported that the RCT found no adverse effects caused by deltamethrin spraying after 3 months' follow-up, but stated that it was not clear how this conclusion had been reached.[17]

Comment

Cluster randomisation limits the power to detect differences between groups, and the interpretation of results for individuals.[9] [10]The review found that concealment of allocation was inadequate in both included RCTs, and was unable to combine data relating to the effect of fly control using insecticide because of significant clinical heterogeneity between the two studies.[17] In the first included RCT,[9] the review noted that the allocation of the villages to intervention was quasi-randomised, as the villages were said to be “arbitrarily allocated”.[17] This RCT noted that fly control with insecticide was unlikely to be a sustainable routine public health measure in countries where trachoma prevalence is highest.[9] The second included RCT noted that long-term insecticide use as a control measure might lead to the evolution of insecticide resistance.[10] The review also noted that, although the two included RCTs found evidence of benefit with fly control using insecticide, the sustainability of such an intervention, and the possible untoward effects of prolonged usage of such chemicals, were uncertain.[17] Hence, although the RCTs found evidence of a short-term benefit, it is unlikely that this intervention would be cost effective or acceptable (from an environmental point of view) were large-scale implementation attempted: the purpose of these trials was to demonstrate that fly-control interventions in general might be effective.

Substantive changes

No new evidence

2007; 2007: 0706.
Published online 2007 December 6.

Fly control using insecticide plus mass antibiotic treatment

Summary

We found no direct information about the effects of insecticide plus mass antibiotic treatment on fly control.

Benefits

Fly control using insecticide plus mass antibiotic treatment versus mass antibiotic treatment alone:

We found no systematic reviews or RCTs of sufficient quality on fly control using insecticide plus mass antibiotic treatment.

Harms

Fly control using insecticide plus mass antibiotic treatment versus mass antibiotic treatment alone:

We found no systematic reviews or RCTs of sufficient quality.

Comment

None.

Substantive changes

No new evidence

2007; 2007: 0706.
Published online 2007 December 6.

Health education

Summary

INCIDENCE RATES Compared with control: Health education at 6 months may be more effective at reducing the incidence of active trachoma compared with control ( very low-quality evidence ).

Benefits

Health education versus no intervention:

We found one systematic review (search date 2005)[17] on the effect of environmental sanitary interventions, which identified one RCT. In the RCT, four villages were randomised to receive either: mass topical tetracycline treatment plus a health-education programme; mass topical tetracycline treatment alone; a health-education programme alone; or no intervention (1810 people in 4 villages, all ages).[17] The health-education programme consisted of information on personal and family hygiene, including household sanitation, and information on trachoma and its complications. It included posters and booklets, and was conducted for 1 week per month for 6 months.[17] The review found that the incidence of active trachoma was significantly lower in the health-education-alone village than in the control village (absolute numbers not reported; OR 2.4, 95% CI 1.1 to 5.1).[17] However, the review found it difficult to draw conclusions from the RCT because it included only one village in each arm, did not use concealment of allocation, and did not adequately allow for differences in the unit of allocation and the unit of analysis.[17]

Health education versus antibiotics:

We found one systematic review (search date 2004) on promoting face washing, which identified two RCTs comparing health education plus face washing versus antibiotics. However, it was not possible to extract data relating to the health-education and face-washing interventions separately.[13]

Harms

Health education versus no intervention:

The review gave no information about harms.[17]

Comment

None.

Substantive changes

No new evidence

2007; 2007: 0706.
Published online 2007 December 6.

Antibiotics

Summary

INCIDENCE RATES Compared with placebo: We don’t know whether oral or topical antibiotics may be more effective at reducing the prevalence of active trachoma at 3 months compared with placebo ( very low-quality evidence ). Oral azithromycin compared with topical tetracycline: We don’t know whether oral azithromycin may be more effective at reducing the prevalence of active trachoma at 3–12 months compared with topical tetracycline (very low-quality evidence). Oral antibiotics other than azithromycin compared with topical antibiotics: We don’t know whether oral antibiotics other than azithromycin may be more effective at reducing the prevalence of active trachoma at 3–12 months compared with topical tetracycline (very low-quality evidence). Topical tetracycline plus face washing compared with control: Topical tetracycline plus face washing is more effective at 3 months at reducing the prevalence of trachoma compared with no face washing in children ( moderate-quality evidence ). Promotion of topical tetracycline plus face washing compared with tetracycline alone: Promotion of topical tetracycline plus face washing may be more effective at reducing the risk of "severe trachoma" at 1 year, but may be not reduce the risk of "any trachoma" compared with topical tetracycline alone ( low-quality evidence ).

Benefits

We found one systematic review (search date 2005; see comment below).[18]

Oral or topical antibiotics versus placebo or no treatment:

The review included nine RCTs (8 reports; 2177 people) comparing topical or oral antibiotics versus control (no treatment, placebo, or a monthly vitamin tablet) (see table 1 ).[15] [19] [20] [21] [22] [23] [24] [25] The review did not meta-analyse results because of statistical and clinical heterogeneity (see comment below).[18] At 3 months, six RCTs found that antibiotic significantly decreased the proportion of people with active trachoma compared with control (P less than 0.05), whereas three RCTs found no significant difference in active trachoma between antibiotic and control.[18] At 12 months, three RCTs found that antibiotic significantly reduced the proportion of people with active trachoma compared with control (P less than 0.05); however, one RCT found no significant difference in active trachoma between antibiotic and control.[18]

Table 1
Interventions to prevent scarring trachoma by reducing active trachoma: RCTs of antibiotics compared with no treatment, placebo, or a monthly vitamin tablet in people with active trachoma (see text).

Oral azithromycin versus topical tetracycline:

The review identified six RCTs (4 reports; 7666 people) comparing oral azithromycin versus topical tetracycline (see table 2 ).[26] [27] [28] [29] The review did not pool results because of trial heterogeneity (see comment below).[18] At 3 months, two RCTs found that oral azithromycin significantly reduced the proportion of people with active trachoma compared with topical tetracycline (P less than 0.05); however, four RCTs found no significant difference in active trachoma between oral azithromycin and topical tetracycline.[18] At 12 months, two RCTs found that oral azithromycin significantly reduced the proportion of people with active trachoma compared with topical tetracycline (P less than 0.05); however, two RCTs found no significant difference in active trachoma between oral azithromycin and topical tetracycline.[18]

Table 1
Interventions to prevent scarring trachoma by reducing active trachoma: RCTs comparing rates of active trachoma and bacteriological infection after oral azithromycin or topical tetracycline (see text).

Oral antibiotics other than azithromycin versus topical antibiotics:

The review[18] identified three RCTs[20] [22] [24] comparing oral antibiotics other than oral azithromycin versus a topical antibiotic. The review did not meta-analyse results because of statistical and clinical heterogeneity (see comment below).[18] At 3 months, one RCT found that oral antibiotics significantly decreased the proportion of people with active trachoma compared with topical antibiotics (P less than 0.05); however, two RCTs found no significant difference in active trachoma between oral antibiotics and topical antibiotics.[18] At 12 months, three RCTs found no significant difference in active trachoma between oral antibiotics and topical antibiotics (reported as not significant).[18]

Topical tetracycline plus face washing:

See benefits of face washing plus antibiotics.

Harms

The review reported that none of the included RCTs reported on the adverse effects of antibiotic treatment.[18]

Topical tetracycline plus face washing:

See harms of face washing plus antibiotics.

Comment

Outcomes were reported by the systematic review at 3 and 12 months.[18] As not all the RCTs collected outcomes at those times, the review reported as at 3 months those outcomes measured by RCTs before 6 months, and as at 12 months those outcomes measured by RCTs between 6 and 18 months.[18] Where more than one outcome was available, the nearest reported to 3 or 12 months was selected.[18]

Oral or topical antibiotics versus placebo or no treatment:

The RCTs were undertaken in various settings. Most were in children attending boarding schools.[18] The RCTs were all of moderate or poor quality, and many lacked intention-to-treat analysis.[18] Antibiotic treatments included topical and oral doses. The review stated that “no conclusions can be drawn on the effectiveness of antibiotic treatment for active trachoma, but there is a suggestion of a reduction in the point prevalence of the relative risk for those treated with either oral or topical antibiotics”.[18]

Oral azithromycin versus topical tetracycline:

Two of the RCTs included in the review were small and of low powered.[27] [29] A third cluster RCT compared mass treatment, in which people were treated irrespective of disease status, and were randomly allocated by village.[28] Correlation analysis found some similarity between individuals within a cluster, limiting the validity of results. The review found no evidence regarding the development of bacterial resistance.[18]

Topical tetracycline plus face washing:

See comment under face washing plus antibiotics.

Substantive changes

No new evidence

2007; 2007: 0706.
Published online 2007 December 6.

Surgery

Summary

SURGERY SUCCESS Compared with other types of eyelid surgery: Bilamellar tarsal rotation may be more effective at increasing operative success rates (no lashes in contact with the globe in the primary position of gaze, and complete lid closure with gentle voluntary effort) in people with minor and major trichiasis compared with eversion splinting, tarsal advance, tarsal grooving, cryoablation, and electrolysis, but it may be no different to tarsal advance and rotation ( very low-quality evidence ). RECURRENCE RATES Bilamellar tarsal rotation compared with tarsal advance and rotation: Bilamellar tarsal rotation may have similar recurrence rates compared with tarsal advance and rotation ( low-quality evidence ).

Benefits

We found one systematic review (search date 2006) on interventions for trachoma trichiasis,[30]which included three RCTs comparing different surgical interventions.[31] [32] [33]The review did not meta-analyse data from the RCTs, because the interventions tested were varied, and there was heterogeneity between studies. In the first two included RCTs, one experienced surgeon performed most of the operations.[31] [32] In the third included RCT, surgery was performed by second-year ophthalmology residents trained in the techniques employed, and supervised by an experienced consultant ophthalmic surgeon and senior resident.[33] The RCTs defined operative success as no lashes in contact with the globe in the primary position of gaze, and complete lid closure with gentle voluntary effort. The first two RCTs reported outcomes by severity of trichiasis before surgery. The third RCT analysed combined results.

Major trichiasis:

The first included RCT (165 Omani villagers, 165 eyelids) compared five surgical techniques: bilamellar tarsal rotation, eversion splinting, tarsal advance, tarsal grooving, and tarsal advance and rotation.[31] It found that bilamellar tarsal rotation significantly increased operative success after 2 weeks compared with eversion splinting, tarsal advance, and tarsal grooving (30/44 [68%] with bilamellar tarsal rotation v 8/25 [32%] with eversion splinting, RR 2.13, 95% CI 1.16 to 3.91; 30/44 [68%] with bilamellar tarsal rotation v 11/41 [27%] with tarsal advance, RR 2.5, 95% CI 1.5 to 4.4; 30/44 [68%] with bilamellar tarsal rotation v 3/32 [9%] with tarsal grooving, RR 7.3, 95% CI 2.4 to 21.8). It found no significant difference between bilamellar tarsal rotation and tarsal advance and rotation in operative success after 2 weeks (30/44 [68%] with bilamellar tarsal rotation v 10/23 [43%] with tarsal advance and rotation; RR 1.57, 95% CI 0.94 to 2.60). However, the trial was underpowered and did not use an intention-to-treat analysis. The second included RCT (Omani villagers, 200 eyelids) compared bilamellar tarsal rotation versus tarsal advance and rotation.[32] It found that bilamellar tarsal rotation significantly increased operative success after 25 months compared with tarsal advance and rotation (HR of failure: tarsal advance and rotation v bilamellar tarsal rotation 3.1, 95% CI 1.9 to 5.2).

Minor trichiasis:

The second included RCT (Omani villagers, 172 eyelids) compared three treatments for minor trichiasis: bilamellar tarsal rotation, cryoablation, and electrolysis.[32] It found that bilamellar tarsal rotation significantly increased operative success after 25 months compared with both other treatments (HR of failure: electrolysis v bilamellar tarsal rotation 6.1, 95% CI 2.9 to 12.8; HR of failure: cryoablation v bilamellar tarsal rotation 7.5, 95% CI 3.6 to 15.4).

Minor and major trichiasis:

The third included RCT (153 Ethiopians, 256 eyelids) compared bilamellar tarsal rotation (Weis) versus tarsal advance and rotation (Trabut).[33] Successful outcomes were similar in the two groups (99/115 (86%) with bilamellar tarsal rotation v 107/122 (88%) with tarsal advance and rotation) as were recurrence rates (12/115 (10%) with bilamellar tarsal rotation v 15/122 (12%) with tarsal advance and rotation; P = 0.711).

Harms

Adverse outcomes of surgery were: overcorrection with corneal exposure, ulceration, phthisis bulbi, and severe recurrent trichiasis.[31] [34] In the first two RCTs included in the review major trichiasis and defective closure were more common after eversion splinting, tarsal advance, and tarsal grooving than after bilamellar tarsal rotation and tarsal advance and rotation (significance not reported).[31] [32] Cryoablation of the eyelashes can cause necrosis of the lid margin and corneal ulcers. In the second RCT, cryoablation was the only procedure associated with onset of phthisis bulbi (2/57 [3.5%] cases).[32]

The third included RCT reported that the non-serious complications of lid notching and pyogenic granuloma occurred significantly more frequently with bilamellar tarsal rotation (absolute numbers not reported; P = 0.002).[33] There were four cases of overcorrection in the bilamellar-tarsal-rotation group (4/115 [3.5%]) compared with none with tarsal-advance-and-rotation group (significance not reported). No major harms were reported.[33]

Further details of harms are summarised in table 3 .

Table 1
Summary of harms after surgery for scarring trachoma (see text).

Comment

In the first two included RCTs, definitions of major trichiasis and minor trichiasis are specific to these trials.[31] [32] In both included RCTs comparing surgical interventions, one experienced operator performed most of the surgery. The evidence of both benefits and harms may not be applicable to different operators, or where the quality of surgical equipment does not match those in the trials.

Effect of surgical setting:

The systematic review[30]included one RCT (158 people with major trichiasis) assessing whether the site of surgery affected uptake. It compared village-based versus health centre-based tarsal rotation surgery for major trichiasis.[35] It found that attendance rates for surgery were not significantly different between sites (57/86 [66%] with village-based surgery v 32/72 [44%] with health centre-based surgery; RR 1.5, CI not reported). Problems with the unit of randomisation prevented the calculation of confidence limits for the relative risks stated. The RCT found no significant difference between settings for operative success rate (defined as no evidence of trichiasis) after 3 months (91% with village-based surgery v 94% with health centre-based surgery; absolute numbers and P value not reported; reported as not significant). However, the RCT may have been too small to detect clinically important differences.[35]

Effect of different surgeons:

One RCT suggested that the risk of trichiasis recurrence postoperatively varied significantly (P less than 0.001) between different surgeons following the same protocols on the same patient groups.[36]However, one RCT identified by the systematic review[30] compared ophthalmologists versus integrated eye-care workers performing bilamellar tarsal rotation in Ethiopia. It found found no significant difference in rates of recurrence at 3 months, although people who could not be followed up (269/982 [27%]) were “assumed to have no recurrence” (recurrence: 47/370 [13%] with ophthalmologists v 34/343 [10%] with integrated eye-care workers; P = 0.24).[37]

Substantive changes

Surgery One systematic review added;[30]categorisation unchanged (Likely to be beneficial).

2007; 2007: 0706.
Published online 2007 December 6.

Surgery plus antibiotics

Summary

RECURRENCE RATES Surgery plus antibiotics compared with surgery alone: Azithromycin given at the time of, and 6 months after posterior lamellar tarsal rotation, to people who have undergone surgery, and to children living in their households, is no more effective at reducing the rates of recurrent trichiasis at 12 months compared with surgery alone ( moderate-quality evidence ).

Benefits

Posterior lamellar tarsal rotation plus azithromycin versus posterior lamellar tarsal rotation alone:

We found one systematic review (search date 2006)[30]which identified one RCT (451 people in Gambia; in bilateral cases only the eye with more severe trichiasis was included). [36] The RCT assessed whether giving people who had undergone surgery and the children living in their households azithromycin (single perioperative dose, 1 g for adults; 20 mg/kg for children, followed by a second dose 6 months later) led to a difference in the incidence of recurrence after posterior lamellar tarsal rotation.[36]All people, regardless of randomisation, were given tetracycline eye ointment to self administer for 2 weeks postoperatively. It found similar rates of recurrence at 12 months between the azithromycin and no-azithromycin groups (any trichiasis at 12 months: 84/204 [41.2%] with azithromycin v 92/222 [41.4%] with control; P value not reported).[36]

Harms

Posterior lamellar tarsal rotation plus azithromycin versus posterior lamellar tarsal rotation alone:

The RCT included in the review[30] found that adverse effects at follow-up included one postoperative lid infection, which settled after oral antibiotics, and two cases of defective lid closure, but did not state whether these occured in the surgery-plus-azithromycin group or in the surgery-alone group.[36]

Comment

None.

Substantive changes

Surgery plus antibiotics New option added with one systematic review;[30] categorised as Unlikely to be beneficial.


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