A randomised controlled trial of azithromycin following surgery for trachomatous trichiasis in the Gambia

Surgery versus epilation for the treatment of minor trichiasis in Ethiopia: a randomised controlled noninferiority trial

BACKGROUND

Trachomatous trichiasis can cause corneal damage and visual impairment. WHO recommends surgery for all cases. However, in many regions surgical provision is inadequate and patients frequently decline. Self-epilation is common and was associated with comparable outcomes to surgery in nonrandomised studies for minor trichiasis (<six lashes touching eye). This trial investigated whether epilation is noninferior to surgery for managing minor trichiasis.

METHODS AND FINDINGS

1,300 individuals with minor trichiasis from Amhara Regional State, Ethiopia were recruited and randomly assigned (1:1) to receive trichiasis surgery or epilation. The epilation group were given new forceps and epilation training. The surgical group received trichiasis surgery. Participants were examined every 6 months for 2 years by clinicians masked to allocation, with 93.5% follow-up at 24 months. The primary outcome measure ("failure") was ≥five lashes touching the eye or receiving trichiasis surgery during 24 months of follow-up, and was assessed for noninferiority with a 10% prespecified noninferiority margin. Secondary outcomes included number of lashes touching, time to failure, and changes in visual acuity and corneal opacity. Cumulative risk of failure over 24 months was 13.2% in the epilation group and 2.2% in the surgical group (risk difference = 11%). The 95% confidence interval (8.1%-13.9%) includes the 10% noninferiority margin. Mean number of lashes touching the eye was greater in the epilation group than the surgery group (at 24 months 0.95 versus 0.09, respectively; p<0.001); there was no difference in change in visual acuity or corneal opacity between the two groups.

CONCLUSIONS

This trial was inconclusive regarding inferiority of epilation to surgery for the treatment of minor trichiasis, relative to the prespecified margin. Epilation had a comparable effect to surgery on visual acuity and corneal outcomes. We suggest that surgery be performed whenever possible but epilation be used for treatment of minor trichiasis patients without access to or declining surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00522912.

Latrine promotion for trachoma: assessment of mortality from a cluster-randomized trial in Ethiopia

Trachoma control strategies, including latrine construction and antibiotic distribution, are directed at reducing ocular chlamydia, but may have additional benefits. In a cluster-randomized clinical trial, 24 subkebeles (administrative geographic units) in Ethiopia were offered a single mass azithromycin treatment, and half were randomized to receive an intensive latrine promotion. At a follow-up census 26 months after the baseline treatment, 320 persons had died. The mortality rate of children 1-5 years of age was 3.87 (95% confidence interval [CI] = 2.19-6.82) per 1,000 person-years in the latrine promotion arm, and 2.72 (95% CI = 1.37-5.42) per 1,000 person-years in the control arm. In a multi-level mixed effects logistic regression model controlling for age, there was no difference in mortality in persons randomized into the latrine or control arms (odds ratio = 1.18, 95% CI = 0.89-1.58). Latrine promotion provided no additional effect on mortality in the context of an azithromycin distribution program (clinicaltrials.gov, #NCT00322972).

Innate immune responses and modified extracellular matrix regulation characterize bacterial infection and cellular/connective tissue changes in scarring trachoma

Trachoma is the most common infectious cause of blindness and a major public health problem in many developing countries. It is caused by recurrent ocular infection with Chlamydia trachomatis in childhood, with conjunctival scarring seen later in life. The pathogenesis of trachomatous scarring, however, is poorly understood, and this study was carried out to investigate the immunofibrogenic correlates of trachomatous conjunctival scarring. A case-control study of 363 cases with conjunctival scarring and 363 control participants was conducted. Investigations included in vivo confocal microscopy (IVCM) assessment, quantitative real-time PCR gene expression, C. trachomatis detection, and nonchlamydial bacterial culture. Trachomatous scarring was found to be strongly associated with a proinflammatory, innate immune response with increased expression of psoriasin, interleukin-1β, tumor necrosis factor alpha, defensin-β4A, chemokine ligand 5, and serum amyloid A1. There was also differential expression of various modifiers of the extracellular matrix, including metalloproteinases 7, 9, 10, and 12, tissue inhibitor of matrix metalloproteinase 1, and secreted protein acidic cystein-rich-like 1. The expression of many of these genes was also significantly associated with the presence of nonchlamydial bacterial infection. These infections had a marked effect on conjunctival immune processes, including an increased inflammatory infiltrate and edema seen with IVCM. This study supports the possibility that the immunofibrogenic response in scarring trachoma is partly stimulated by nonchlamydial bacterial infection, which is characterized by the expression of innate factors.

The clinical phenotype of trachomatous trichiasis in Ethiopia: not all trichiasis is due to entropion

PURPOSE

Trachomatous trichiasis (TT) is usually described as a cicatricial entropion of the upper lid; however, other forms of trichiasis have been reported. This variation in clinical phenotype is potentially important for treatment guidelines. Therefore, this study was conducted to investigate the range of disease type and severity encompassed by TT.

METHODS

Individuals presenting with TT to surgical treatment campaigns were examined by a single ophthalmologist using the Detailed WHO Trachoma Grading System. Additional features were graded, including type of trichiatic lashes (metaplastic, misdirected, and entropic), lower lid trichiasis, entropion severity, and lid margin mucocutaneous junction (MCJ) position.

RESULTS

Recruited were 2556 individuals with previously unoperated TT in at least one eye (4310 eyes). The median number of lashes touching the eye was 2 (range, 0 [epilating]-133). Entropion was absent or mild in 2328 (54.0%) eyes, moderate in 1259 (29.2%) eyes, and severe in 723 (16.8%) eyes. Trichiatic lashes were predominantly metaplastic or misdirected (80.2%), rather than secondary to entropion; 4204 (97.7%) had anteroplacement of the MCJ; and lower lid trichiasis was present in 494 (11.5%). Entropion was more severe among those with a low BMI, those who were female, those aged less than 50 years, and those with moderate to severe conjunctival inflammation, central corneal opacity, and severe conjunctival scarring.

CONCLUSIONS

Many patients with TT have minimal or no entropion. The trichiasis is frequently attributable to metaplastic or misdirected eyelashes. The results of tarsal rotation surgery in TT patients without manifest entropion should be investigated and potentially alternative treatment strategies evaluated.

Active trachoma is associated with increased conjunctival expression of IL17A and profibrotic cytokines

The immunological basis of scarring trachoma is not well understood. It is unclear whether it is driven primarily through cell-mediated adaptive or epithelial-cell-derived innate responses. The purpose of this study was to investigate the expression of the inflammatory and fibrogenic mediators which may be involved. We conducted a cross-sectional survey of children living in an untreated trachoma-endemic community in Tanzania. The children were examined for signs of trachoma, and swabs were collected for bacteriological culture and RNA and DNA isolation. Chlamydia trachomatis was detected by the Amplicor PCR test. The expression of the following genes was measured by quantitative reverse transcription-PCR (RT-PCR): S100A7, IL1B, IL17A, IL23A, CXCL5, CCL18, TLR2, NLRP3, KLRD1, CTGF, and MMP9. Four hundred seventy children under the age of 10 years were included. Follicular trachoma (TF) was detected in 65 children (14%), C. trachomatis was detected in 25 (5%), and bacterial pathogens were cultured in 161 (34%). TF was associated with significantly increased expression of S100A7, IL17A, CCL18, CXCL5, and CTGF. Expression was increased further in the presence of papillary inflammation. Nonchlamydial bacterial infection was associated with increased expression of IL17A, CXCL5, CCL18, and KLRD1. IL17A expression was associated with increased expression of S100A7, CXCL5, CCL18, KLRD1, and CTGF. These data are consistent with a role for IL-17A in orchestrating the proinflammatory response in trachoma. Its activity may be promoted either as part of the cell-mediated response or through innate pathways. It may drive a range of proinflammatory factors leading to excessive tissue damage and repair involving fibrosis.

What is causing active trachoma? The role of nonchlamydial bacterial pathogens in a low prevalence setting

PURPOSE

In low prevalence settings, clinically active follicular trachoma (TF) is often found in the absence of detectable Chlamydia trachomatis. The reasons for this persistent follicular phenotype are not well understood; one possible explanation is that other bacterial species are provoking the inflammatory response. This study investigated the relationship between TF, C. trachomatis, and nonchlamydial bacterial infection.

METHODS

A cross-sectional survey was conducted in a trachoma endemic village in Tanzania. All available children were examined for trachoma and swabs were collected for microbiologic culture (blood and chocolate agar) and C. trachomatis PCR (Amplicor).

RESULTS

Four hundred seventy-three children under 10 years of age were recruited for this study. The prevalences of TF and C. trachomatis were 13.7% and 5.3%, respectively, and were not associated. Bacteria were cultured from 305 (64.5%) swab samples; 162 (34.3%) grew a pathogen (with or without a commensal organism) and 143 (30.2%) grew commensal bacteria only. The most common pathogens were Streptococcus pneumoniae and Haemophilus influenzae (type B and non-type B). The presence of bacterial pathogens was associated with TF (odds ratio, 4.68; 95% confidence interval, 2.31-9.50; P < 0.001).

CONCLUSIONS

In regions with low levels of endemic trachoma, it is possible that much of the TF that is observed is attributable to nonchlamydial bacterial pathogens. It is plausible that individuals who have previously developed a follicular conjunctivitis in response to C. trachomatis may more readily reform conjunctival follicles when challenged with certain other bacterial species.

Challenges of trachoma control: an assessment of the situation in northern Nigeria

Over the last three decades, a lot has been achieved in the control of trachoma worldwide. New assessment techniques, effective evidence-based control strategy with new methods and drugs, and an aggressive global partnership for the control of the disease have evolved. As such the number of people with the disease and blindness due to the disease had drastically reduced. Trachoma is now only responsible for about 4% of blindness worldwide down from 12% some few decades ago. Some countries are on the verge of eliminating the disease as a public health problem. Despite these achievements numerous challenges remain for achieving trachoma control in endemic communities. This article highlights the challenges faced in one of the known trachoma endemic areas – northern Nigeria. Aspects on the dearth of complete situational data on trachoma, fragmented implementation of the SAFE strategy, community apathy, difficulties faced in ensuring safe, and quality lid surgery in the most difficult terrain where the disease thrives are discussed here. Other unique challenges like managing children with severe trichiasis, curbing the high rate of early-onset recurrence of trichiasis after lid rotation surgery and challenges to maintain supply of antibiotics and implementation of facial cleanliness and environmental improvement components of the control strategy are presented along with the learnt experiences and recommendations. These challenges and their remedies are likely to be shared by other trachoma endemic areas in Africa.

Rates and risk factors for unfavorable outcomes 6 weeks after trichiasis surgery

PURPOSE

Several studies of trichiasis recurrence suggest an association between surgical factors and long-term recurrence, yet data on short-term risk factors are limited. This study was conducted to evaluate risk factors for early trichiasis recurrence and other unfavorable short-term outcomes.

METHODS

Trichiasis patients presenting for surgery were evaluated for presence of active trachoma and signs of cicatricial outcomes of trachoma, including number of trichiatic lashes, epilation, and entropion. Surgical factors recorded included incision length, surgery duration, and the surgeon performing the operation. Participants were followed up for 6 weeks after surgery and evaluated for eyelid closure defect and trichiasis recurrence; in addition, in two thirds of the patients, eyelid contour abnormality and granuloma formation were evaluated.

RESULTS

First-time trichiasis surgery was performed on 2615 eyelids. Of these, 2601 eyelids without surgical failure were followed up 6 weeks after surgery. Of the eyelids treated, 2.3% had recurrent trichiasis and 1.3% had an eyelid closure defect. Data on eyelid contour abnormalities and granuloma formation were recorded for 1881 eyes, with rates of 1.2% and 10.5%, respectively. Associated risk factors differed by outcome. Surgeon was predictive of eyelid closure defect and granuloma formation. Eyelids with short incisions were nearly four times more likely to have recurrent trichiasis (95% confidence interval, 1.7-9.3). Baseline trichiasis severity was predictive of eyelid contour abnormalities and recurrent trichiasis. Epilation was associated with granuloma formation, but was protective against eyelid closure defect.

CONCLUSIONS

Surgical factors are important predictors of unfavorable outcomes in the weeks immediately after surgery. Although the overall rate of serious uncorrectable unfavorable outcomes was very low, the high rate of granuloma formation, which can be treated by removal, highlights the need for follow-up of patients after trichiasis surgery. (ClinicalTrials.gov number, NCT00347776.).

Bacterial infection in scarring trachoma

PURPOSE

To assess whether non-chlamydial bacterial infection is associated with trachomatous scarring in adults.

METHODS

This was a case-control study of 360 cases with trachomatous scarring but without trichiasis, and 360 controls without scarring. All participants underwent clinical examination, and a swab was taken from the inferior conjunctival fornix. Samples were inoculated onto blood and chocolate agar later that day.

RESULTS

Bacterial isolates were identified in 54.0% of cases compared with 34.6% of controls (P < 0.001). A multivariate logistic regression model adjusted for age and lack of education showed that scarring was associated with the presence of commensal organisms (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.01-2.09) and was strongly associated with the presence of pathogenic organisms (OR, 4.08; 95% CI, 1.59-10.45). There was an increasing prevalence of all bacterial isolates with increasing severity of scarring (P(trend) < 0.001).

CONCLUSIONS

Trachomatous scarring is strongly associated with non-chlamydial bacterial infection compared with controls. The role of such infection with regard to scarring progression should be investigated and may have important implications for trachoma control strategies and prevention of blindness.

Clearing the backlog: trichiasis surgeon retention and productivity in northern Ethiopia

Background

In 2006 there were an estimated 645,000 people in Amhara, Ethiopia, with trachomatous trichiasis (TT) who needed surgery. Despite an extensive integrated eye care worker training programme (IECW) and robust support for TT surgical services, productivity has not reached targets. We investigated why surgeon productivity was below target.

Methodology/Principal Findings

Confidential interviews were conducted in person with TT surgeons trained from 24 selected districts in Amhara Region and their supervisors. Determinants of attrition and productivity were investigated. We interviewed 225 people who had received IECW training; 139 (59%) had subsequently changed career/job. Staff retention was associated with good road access to their health centre, mobile telephone network and a shorter time from initial training. Amongst the 94 IECW still working in the programme, the average number of patients operated was 41/year, which was mostly (86%) done through outreach campaigns and only 14% of cases were performed in the static facilities where they routinely worked. Spot checks were made of surgical instruments and consumables: only 3/94 IECW had the minimum instruments and consumables to perform surgery. The main barriers to operating were lack of time, shortage of consumables, lack of patients, lack of support and equipment problems. Very few IECW received ongoing supervision or active management.

Conclusions/Significance

Surgeon attrition rates are high. Vertical surgery campaigns were effective in treating large numbers of cases, whilst static-site service productivity was low. Good health system management is key to building a well-staffed and well-run service.

Blindness from trachoma is caused by the abrasive effect of trichiasis (in-turned eyelashes). Surgery is performed to correct this anatomical abnormality, and prevent blindness. Despite the progress made in many regions in controlling the active/infectious stages of this disease, the global prevalence of trichiasis remains about the same. Current surgical activity is barely keeping abreast of incident trichiasis; this is undermining all the other efforts to control trachoma. We examine staff retention and productivity in Amhara Region, Ethiopia, where many hundreds of health care workers have been trained to perform the surgery. We found that the majority of people trained to do the surgery are now not in a position to do so. Amongst the sub-set that is still active within the programme, surgical productivity is low, with most surgery performed during “outreach campaigns” Insufficient surgical instruments and consumables were frequent problems. Strengthened health-systems management can overcome many of the problems that are holding back the delivery of an effective trichiasis surgical service.

Quality assurance in trichiasis surgery: a methodology

BACKGROUND

Trachoma remains a significant cause of blindness in many parts of the world. The major route to blindness involves upper lid entropion leading to trachomatous trichiasis (TT), which promotes progressive corneal opacification. The provision of surgery to correct TT in the populations most severely affected is a major challenge for the global effort to eliminate trachoma blindness by the year 2020. Most attention has focused on increasing the quantity of TT surgery performed, and large numbers of non-doctor operators have been trained to this end. Surgical audit by those performing TT surgery is not a routine part of any national trachoma control programme, and no effective mechanism exists for identifying surgeons experiencing poor outcomes. The authors propose a methodology for surgical audit at the level of the individual surgeon based on Lot Quality Assurance.

METHODS

A set number of patients operated on previously for upper eyelid TT are examined to detect the recurrence of TT. The number of recurrent cases found will lead to categorisation of the TT surgeon to either 'high recurrence' or 'low recurrence' with reasonable confidence. The threshold of unacceptability can be set by individual programmes according to previous local studies of recurrence rates or those from similar settings.

CONCLUSIONS

Identification of surgeons delivering unacceptably high levels of recurrent TT will guide managers on the need for remedial intervention such as retraining.

Conjunctival transcriptome in scarring trachoma

Trachoma is a poorly understood immunofibrogenic disease process, initiated by Chlamydia trachomatis. Differences in conjunctival gene expression profiles between Ethiopians with trachomatous trichiasis (with [TTI] or without [TT] inflammation) and controls (C) were investigated to identify relevant host responses. Tarsal conjunctival swab samples were collected for RNA isolation and C. trachomatis PCR. Transcriptome-wide microarray experiments were conducted on 42 samples (TTI, n = 13; TT, n = 15; C, n =14). Specific results were confirmed by using multiplex quantitative reverse transcription-PCR for 16 mRNA targets in an independent collection of case-control samples: 386 case-control pairs (TTI, n = 244; TT, n = 142; C, n = 386). The gene expression profiles of cases were consistent with squamous metaplasia (keratins, SPRR), proinflammatory cytokine production (IL1β, CXCL5, and S100A7), and tissue remodeling (MMP7, MMP9, MMP12, and HAS3). There was no difference in the level of IFNγ between cases and controls. However, cases had increased INDO, NOS2A, and IL13RA2 and reduced IL13. C. trachomatis was detected in 1/772. Cases show evidence of ongoing inflammation and tissue remodeling, which were more marked where clinical inflammation was also present. Significantly, these processes appear to be active in the absence of current C. trachomatis infection. There was limited evidence of a T(H)1 response (INDO and NOS2A) and no association between a T(H)2 response and cases. The epithelium appears to be actively involved in late cicatricial stages of trachoma through the production of proinflammatory factors (IL1β, CXCL5, and S100A7). Longitudinal studies are needed to investigate which etiological factors and pathways are associated with progressive scarring and whether simply controlling chlamydial infection will halt progression in people with established cicatricial disease.

Conjunctival expression of matrix metalloproteinase and proinflammatory cytokine genes after trichiasis surgery

PURPOSE. Trachoma, the leading infectious cause of blindness, is a chronic inflammatory scarring condition. Blindness follows the development of trichiasis, which is treated surgically. Unfortunately, it frequently recurs, compromising the treatment. In this study, gene expression analysis was used to examine factors that may be involved in the inflammation and tissue remodeling after surgery. METHODS. Subjects were examined before and at 1 and 4 years after surgery. Conjunctival swab samples were collected for bacterial culture, Chlamydia trachomatis PCR, and RNA isolation at 1 year. Quantitative real-time PCR was performed to measure the expression of tumor necrosis factor-alpha (TNF), interleukin-1beta (IL1B), matrix metalloproteinase-1 (MMP1), MMP-2, MMP-9, tissue inhibitor of matrix metalloproteinase 1 (TIMP-1), TIMP-2, and hypoxanthine phosphoribosyl transferase-1 (HPRT1). RESULTS. Two hundred forty individuals with trachomatous trichiasis were recruited. One year after surgery, recurrent trichiasis was associated with a reduced MMP-1/TIMP-1 ratio (P = 0.029). IL1B expression was elevated in the presence of either conjunctival bacterial infection (P = 0.011) or inflammation (P = 0.002). TNF expression was greater in the Mandinka ethnic group (P < 0.0001), and it was increased when clinical inflammation was associated with nonchlamydial bacterial infection (P = 0.012). MMP-9 expression increased when conjunctival inflammation was associated with bacterial infection (P = 0.007). CONCLUSIONS. Recurrent trichiasis was associated with a reduced MMP-1 to TIMP-1 ratio, which may favor the accumulation of fibrotic tissue. Nonchlamydial bacterial infection may induce factors that contribute to conjunctival tissue remodeling and recurrent trichiasis in trachoma. Prospective studies are needed to assess the potential importance of these and other factors in progressive disease.

Epidemiology and control of trachoma: systematic review

Trachoma is the commonest infectious cause of blindness. Recurrent episodes of infection with serovars A-C of Chlamydia trachomatis cause conjunctival inflammation in children who go on to develop scarring and blindness as adults. It was estimated that in 2002 at least 1.3 million people were blind from trachoma, and currently 40 million people are thought to have active disease and 8.2 million to have trichiasis. The disease is largely found in poor, rural communities in developing countries, particularly in sub-Saharan Africa. The WHO promotes trachoma control through a multifaceted approach involving surgery, mass antibiotic distribution, encouraging facial cleanliness and environmental improvements. This has been associated with significant reductions in the prevalence of active disease over the past 20 years, but there remain a large number of people with trichiasis who are at risk of blindness.

Trichiasis surgery in The Gambia: a 4-year prospective study

PURPOSE

Trachoma is the leading infectious cause of blindness. Conjunctival Chlamydia trachomatis infection causes scarring, entropion, trichiasis, and blinding corneal opacification. Worldwide, there are 8 million people with trichiasis. Although trichiasis surgery can reduce the risk of blindness, retrospective data suggest that long-term recurrence rates may be high. A 4-year prospective investigation of recurrent trichiasis was conducted in The Gambia.

METHODS

Patients with trichiasis were examined at baseline, 6 months, 1 year, and 4 years after posterior lamellar tarsal rotation surgery. Conjunctival swabs for bacteriology and PCR for C. trachomatis were collected at baseline, 6 months, and 1 year.

RESULTS

Three hundred fifty-six Gambian patients were enrolled at baseline and 266 were reassessed at 4 years (94% of surviving patients). The recurrence rates were 32%, 40%, and 41% at 6 months, 1 year, and 4 years, respectively. At 4 years, 30% of patients had bilateral trichiasis and 21% had bilateral corneal opacity. Recurrence was associated with severe conjunctival inflammation and severe trichiasis (>10 lashes) at baseline.

CONCLUSIONS

Trichiasis recurrence rates were high, and most cases recurred within 6 months of surgery. The results suggest that there are important aspects of surgical technique and quality that should to be addressed. Persistent inflammation is strongly associated with recurrence at 4 years.

Pathway-focused arrays reveal increased matrix metalloproteinase-7 (matrilysin) transcription in trachomatous trichiasis

PURPOSE

Several genes that are associated with protection from or susceptibility to trachomatous trichiasis (TT) have been identified through genetic association studies. Yet there have been few studies in which gene expression profiles were assessed in TT cases and disease-free controls. The purpose was to identify genes that are differentially expressed in the upper tarsal conjunctiva of subjects with TT.

METHOD

Pathway-focused gene arrays were used to screen conjunctival RNA expression of 226 gene transcripts of interest. The screening was followed by validation of differentially expressed genes by qRT-PCR on an independent set of samples. Three different techniques were then used to test for quantitative differences in the recovered conjunctival protein fraction.

RESULTS

Focused arrays identified a set of 13 differentially expressed genes. Validation by qRT-PCR confirmed differential expression in four of these genes (COL1A1, COL7A1, MMP7, and TLR6). Increased expression of MMP7 was the only consistent differentially regulated gene in the conjunctival samples of trichiasis subjects. MMP7 was present in isolated conjunctival proteins and in the tissue culture supernatants of peripheral blood lymphocytes after stimulation.

CONCLUSIONS

There is an imbalance in extracellular matrix turnover with minimal contribution of adaptive immune responses at this stage of trichiasis. There was little evidence of broad differential expression in genes characteristic of polar responses of adaptive T cells or macrophages. The control of the MMP7 response and its activity appears significant in the fibrotic changes observed in TT.

Effect of trichiasis surgery on visual acuity outcomes in Ethiopia

OBJECTIVES

To determine the effect of trichiasis surgery on visual acuity.

METHODS

A total of 439 participants in the Surgery for Trichiasis, Antibiotics to Prevent Recurrence (STAR) trial had visual and subjective concerns measured before and 6 months after surgery. Trichiasis surgery was performed in at least 1 eye by integrated eye care workers. Visual acuity was measured using illiterate E versions of Early Treatment Diabetic Retinopathy Study charts with standardized, forced-choice procedures. Improvement was defined as improvement in visual acuity greater than 1 line (5 letters).

RESULTS

The mean improvement in visual acuity for the eyes that had surgery was 0.129 logMAR units (P < .001). Surgery was associated with improvement in visual acuity compared with no surgery (odds ratio, 1.68; 95% confidence interval, 1.04-2.70). Independent predictors of visual acuity improvement in the eyes that had surgery included the number of lashes touching the globe prior to surgery and baseline visual acuity. Among patients, 93.8% described significant pain and 90.4% significant photophobia at baseline compared with only 1.4% and 0.9%, respectively, following surgery.

CONCLUSIONS

Surgery to correct trichiasis appears to provide significant visual acuity improvement as well as a decrease in subjective concerns in patients with trachomatous trichiasis.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00347776.

Strategies to control trachoma

Trachoma is a significant public health problem that is endemic in 57 countries, affecting 40.6 million people and contributing to 4% of the global burden of blindness. Repeated episodes of infection from Chlamydia trachomatis lead to long-term inflammation, scarring of the tarsal conjunctiva and distortion of the upper eyelid with in-turning of eyelashes that abrade the surface of the globe. This constant abrasion, in turn, can cause irreversible corneal opacity and blindness. The Alliance for the Global Elimination of Trachoma by 2020 (GET2020) has adopted the SAFE (Surgery, Antibiotics, Facial cleanliness and Environmental improvement) strategy as the main action against trachoma. Trichiasis surgery reduces the risk of blindness by reversing the in-turning of eyelashes and also improves the quality of life from non-visual symptoms. However, future efforts need to aim at increasing accessibility to surgery and improving acceptance. Antibacterials are required to reduce the burden of infection. Oral azithromycin is as close to the perfect antibacterial as we will get for mass distribution: it is safe, requires only a single oral dose, treatment is usually repeated every 6-12 months, resistance is not seen as a problem, and cost is not a limiting factor with a large donation programme and newer generic versions of the drug. Future focus should be on the details of antibacterial distribution such as coverage, frequency of distribution and target population. The promotion of facial cleanliness through education may be the key to trachoma elimination as it will stop the frequent exchange of infected ocular secretions and thus reduce the transmission of infection. However, innovative methods are required to translate health education and promotion activities into sustainable changes in hygiene behaviour. Environmental improvements should focus on the barriers to achieving facial cleanliness and cost-effective means need to be identified. There are a number of countries already eligible for certification of trachoma elimination and if current momentum continues, blinding trachoma can be eliminated by the year 2020.

The global burden of trachoma: a review

Trachoma is the commonest infectious cause of blindness worldwide. Recurrent infection of the ocular surface by Chlamydia trachomatis, the causative agent, leads to inturning of the eyelashes (trichiasis) and blinding corneal opacification. Trachoma is endemic in more than 50 countries. It is currently estimated that there are about 1.3 million people blind from the disease and a further 8.2 million have trichiasis. Several estimates for the burden of disease from trachoma have been made, giving quite variable results. The variation is partly because different prevalence data have been used and partly because different sequelae have been included. The most recent estimate from the WHO placed it at around 1.3 million Disability-Adjusted Life Years (DALYs). A key issue in producing a reliable estimate of the global burden of trachoma is the limited amount of reliable survey data from endemic regions.

Trachoma

Trachoma is a keratoconjunctivitis caused by ocular infection with Chlamydia trachomatis. Repeated or persistent episodes lead to increasingly severe inflammation that can progress to scarring of the upper tarsal conjunctiva. Trichiasis develops when scarring distorts the upper eyelid sufficiently to cause one or more lashes to abrade the cornea, scarring it in turn and causing blindness. Active trachoma affects an estimated 84 million people; another 7.6 million have end-stage disease, of which about 1.3 million are blind. Trachoma should stand on the brink of extinction thanks to a 1998 initiative launched by WHO--the Global Elimination of Trachoma by 2020. This programme advocates control of trachoma at the community level with four inter-related population-health initiatives that form the SAFE strategy: surgery for trichiasis, antibiotics for active trachoma, facial cleanliness, and environmental improvement. Evidence supports the effectiveness of this approach, and if current world efforts continue, blinding trachoma will indeed be eliminated by 2020.

Azithromycin prevents recurrence of severe trichiasis following trichiasis surgery: STAR trial

PURPOSE

Trichiasis, the potentially visually disabling result of chronic trachoma, is a leading cause of blindness world wide. Surgery can repair trichiasis, but recurrence of severe trichiasis (lashes touching the cornea) following surgery is likely to have immediate vision threatening consequences. Azithromycin use post-surgery appeared to be beneficial against recurrences but there were a mix of severe, moderate, and mild trichiasis; the specific effect on prevention of severe, vision-threatening recurrence is unknown. This randomized, clinical trial determined if treating trichiasis surgical patients with oral azithromycin compared to usual care (topical tetracycline) resulted in a reduction in severe recurrence of trichiasis to one year.

METHODS

In a rural, trachoma hyperendemic district in Ethiopia, 1452 trichiasis patients age 18 or older presenting for surgery were randomly allocated to azithromycin, single 1 gram dose, versus topical tetracycline twice per day for six weeks. The outcome was recurrent severe trichiasis, defined as lashes touching the cornea, or more than 5 lashes touching the globe, to one year.

RESULTS

Patients randomized to receive azithromycin had significantly fewer severe recurrences, 4.2/100 person years overall, compared to those randomized to topical tetracycline, 7.9/100 person years (p < 0.01).

CONCLUSIONS

A single dose of azithromycin has been shown to reduce severe post-surgical trichiasis recurrence rates to one year and should become standard post surgical treatment.

Trachoma

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 (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).

Trichiasis and geoclimatic factors in Mali

Several trachoma surveys conducted in sub-Saharan countries showed different geographical distributions of active trachoma and trichiasis. Trichiasis is more common in southern regions. We analysed the role of geoclimatic factors in determining the distributions of active trachoma and trichiasis in Mali. In each region a random sample of 30 clusters was examined. The prevalence of active trachoma among children and of trichiasis among women was compared, and geographical, environmental and social risk factors were assessed. Logistic regression models were constructed. Multiple regression analysis was applied and models were used to map the probability of active trachoma and trichiasis. The highest prevalence rates of active trachoma (TF/TI) were found in the northern part of Mali reaching 41.1% among children living north of the 15th parallel. Surprisingly, prevalence rates of trichiasis (TT) among women regularly increased from north to south (1.0% north of the 15th parallel vs. 2.8% south; OR=2.91, 95% CI 2.01-4.24). The two related predictive maps showed a gradient SSE/NNW for TF/TI very different from the gradient NS/SW for TT. These opposite spatial distributions could be explained by differences in the pathogenic agent, the natural history of the disease, population susceptibility, grading process or vulnerable group behaviour.

Trachoma: Ancient scourge, disease elimination, and future research

Realistically, global elimination of trachoma could not have been considered until the maturation of innovation and public will that converged with the formation of both the Alliance for the Global Elimination of Trachoma by the year 2020 (GET2020) in 1997 and the public-private partnership, the International Trachoma Initiative (ITI) in 1998. Public-private partnerships are cross-sector collaborations that bring heterogeneous capabilities together to work on difficult problems for which the individual partners share common goals. The work of the ITI and partners to date demonstrates that the SAFE strategy reviewed in this article can work, and that it will revolutionize the control of blinding trachoma. Programs working to eliminate trachoma can achieve the GET2020 goals through expanded partnerships, commitment, and research on program integration into evolving health systems.

Interventions for trachoma trichiasis

BACKGROUND

Trachoma is a leading cause of avoidable blindness. The World Health Organization recommends eliminating trachoma blindness by the SAFE strategy incorporating Surgery, Antibiotic treatment, Facial cleanliness and Environmental hygiene.

OBJECTIVES

This review examined the evidence for the effectiveness of different interventions for trachoma trichiasis.

SEARCH STRATEGY

We identified trials from the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (2005, Issue 3), MEDLINE (1966 to September 2005) PubMed (searched on 21-09-06; last 90 days), EMBASE (1980 to September 2005), LILACS (March 2004) and the reference lists of included studies. We also contacted authors for details of other relevant studies.

SELECTION CRITERIA

We included randomised trials of any intervention intended to treat trachoma trichiasis and trials comparing different methods of delivering the same intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials. We contacted trial authors for missing data when necessary.

MAIN RESULTS

Seven studies met the inclusion criteria. Three studies compared different surgical interventions. These trials suggest the most effective surgery is full-thickness incision of the tarsal plate and rotation of the terminal tarsal strip 180 degrees. One study showed that bilamellar rotation was more effective than unilamellar rotation but the other two studies did not. One trial found double-sided sticking plaster more effective than epilation for the immediate management of trichiasis but required frequent replacement (odds ratio (OR) 0.01, 95% confidence interval (CI) 0.00 to 0.22). Another trial found community-based surgery increased convenience for patients without increasing the risk of complications or recurrence when compared to health centres. One trial found no difference between trichiasis surgery performed by ophthalmologists and integrated eye workers (OR 1.32, 95% CI 0.83 to 2.11). A trial comparing trichiasis surgery with and without concurrent administration of azithromycin found no difference in success rates at one year (OR 0.99, 95% CI 0.67 to 1.46).

AUTHORS' CONCLUSIONS

No trials show interventions for trichiasis prevent blindness. Certain interventions have been shown to be more effective at eliminating trichiasis. Full thickness incision of the tarsal plate and rotation of the lash-bearing lid margin through 180 degrees is probably the best technique and is preferably delivered in the community. The use of double-sided sticking plaster is more effective than epilation as a temporary measure. Surgery may be carried out by an ophthalmologist or a trained ophthalmic assistant. The addition of azithromycin treatment at the time of surgery does not appear to improve outcomes.

A coding polymorphism in matrix metalloproteinase 9 reduces risk of scarring sequelae of ocular Chlamydia trachomatis infection

Background

Trachoma, an infectious disease of the conjunctiva caused by Chlamydia trachomatis, is an important global cause of blindness. A dysregulated extracellular matrix (ECM) proteolysis during the processes of tissue repair following infection and inflammation are thought to play a key role in the development of fibrotic sequelae of infection, which ultimately leads to blindness. Expression and activity of matrix metalloproteinase 9 (MMP-9), a major effector of ECM turnover, is up-regulated in the inflamed conjunctiva of trachoma subjects. Genetic variation within the MMP9 gene affects in vitro MMP9 expression levels, enzymatic activity and susceptibility to various inflammatory and fibrotic conditions.

Methods

We genotyped 651 case-control pairs from trachoma endemic villages in The Gambia for coding single nucleotide polymorphisms (SNPs) in the MMP9 gene using the high-throughput Sequenom^® system. Single marker and haplotype conditional logistic regression (CLR) analysis for disease association was performed.

Results

The Q279R mutation located in exon 6 of MMP9 was found to be associated with lower risk for severe disease sequelae of ocular Chlamydia trachomatis infection. This mutation, which leads to a nonsynonymous amino-acid change within the active site of the enzyme may reduce MMP-9-induced degradation of the structural components of the ECM during inflammatory episodes in trachoma and its associated fibrosis.

Conclusion

This work supports the hypothesis that MMP-9 has a role in the pathogenesis of blinding trachoma.