Longitudinal study of trachomatous trichiasis in the Gambia

Insights into Pathogenesis of Trachoma

Trachoma is the most common infectious cause of blindness worldwide. This review investigates the pathogenesis of trachoma, focusing on its causative agent, transmission pathways, disease progression, and immune responses. Trachoma is caused by serovars A-C of the bacterium Chlamydia trachomatis (Ct). Transmission occurs through direct or indirect exchanges of ocular and nasal secretions, especially in regions with poor hygiene and overcrowded living conditions. The disease is initiated in early childhood by repeated infection of the ocular surface by Ct. This triggers recurrent chronic inflammatory episodes, leading to the development of conjunctival scarring and potentially to trichiasis, corneal opacity, and visual impairment. Exploring the pathogenesis of trachoma not only unveils the intricate pathways and mechanisms underlying this devastating eye disease but also underscores the multifaceted dimensions that must be considered in its management.

Gender differences in trachomatous scarring prevalence in a formerly trachoma hyperendemic district in Tanzania

BACKGROUND

Trachoma is a chronic conjunctivitis caused by the bacterium Chlamydia trachomatis. Repeated infections lead to trachomatous conjunctival scarring which can progress to potentially blinding trachomatous trichiasis (TT). In trachoma hyperendemic conditions, women compared to men have an increased risk of scarring and TT, which can progress to blinding corneal opacification. This study determined if there were gender differences in scarring prevalence and severity when trachoma prevalence approaches elimination, in a formerly trachoma hyperendemic region.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional prevalence study was conducted amongst adults age 15 years and older in Kongwa district, Tanzania in 2019. 3168 persons over age 15 years agreed to be examined and had at least one eye with a gradable image. Ocular photographs were graded for scarring according to a published four-step severity scale. Overall, about half of all study participants had scarring. However, more females (52.3%) had any scarring compared to males (47.2%), OR = 1.22 (95% CI = 1.05-1.43). For every year increase in age, there was a 6.5% increase in the odds of having more severe scarring (95% CI: 5.8%, 7.2%). Women were more likely than men to have severe scarring, OR 2.36 (95% CI: 1.84-3.02). Residence in a community with TF≥10% was associated with a 1.6-fold increased odds of any scarring.

CONCLUSIONS/SIGNIFICANCE

Overall scarring prevalence and more severe scarring prevalence was higher in females compared to males, even adjusting for age and community TF prevalence. The data suggest that processes occur that lead to women preferentially progressing towards more severe scarring compared to men.

Expanding a photographic grading system for trachomatous scarring

BACKGROUND

The purpose was to assess an expansion of a previously published photographic four-step severity grading scale for trachomatous scarring (TS).

METHODS

Images of everted eyelids of adult women in Tanzania were graded for the presence and severity of TS. The previous S3 grade was subdivided into two categories: S3A, one-third to <50% of the upper eyelid conjunctiva scarred; and S3B, 50% to <90%. The reliability and ease of use were evaluated. This new categorisation was then applied to images taken of the same women 5 y prior to evaluate whether it could help detect previously undetected progression.

RESULTS

In total, 142 eyes at baseline and 418 eyes at follow-up after 5 y were graded as S3. Interobserver agreement using the expanded scarring grading scale was a kappa of 0.86. At baseline, 51 (35.9%) eyes were S3A and 91 (64.1%) were S3B. At follow-up after 5 y, 36.6% of the eyes that were previously documented as not having progressed were now detected as having progressed from S3A to S3B. S3B images were more likely to progress to S4 compared with S3A (OR 4.6, 95% CI 2.1 to 9.9).

CONCLUSIONS

Adding S3A and S3B is reliable and detects more scarring progression. It will be beneficial for future studies analysing TS in photographs.

Risk factors for the progression of trachomatous scarring in a cohort of women in a trachoma low endemic district in Tanzania

Background

Trachoma, a chronic conjunctivitis caused by Chlamydia trachomatis, is the leading infectious cause of blindness worldwide. Trachoma has been targeted for elimination as a public health problem which includes reducing trachomatous inflammation—follicular prevalence in children and reducing trachomatous trichiasis prevalence in adults. The rate of development of trachomatous trichiasis, the potentially blinding late-stage trachoma sequelae, depends on the rate of trachomatous scarring development and progression. Few studies to date have evaluated the progression of trachomatous scarring in communities that have recently transitioned to a low trachomatous inflammation—follicular prevalence.

Methodology/Principal findings

Women aged 15 and older were randomly selected from households in 48 communities within Kongwa district, Tanzania and followed over 3.5 years for this longitudinal study. Trachomatous inflammation—follicular prevalence was 5% at baseline and at follow-up in children aged 1–9 in Kongwa, Tanzania. 1018 women aged 15 and older had trachomatous scarring at baseline and were at risk for trachomatous scarring progression; 691 (68%) completed follow-up assessments. Photographs of the upper tarsal conjunctiva were obtained at baseline and follow-up and graded for trachomatous scarring using a previously published four-step severity scale. The overall cumulative 3.5-year progression rate of scarring was 35.3% (95% CI 31.6–39.1). The odds of TS progression increased with an increase in age in women younger than 50, (OR 1.03, 95% CI 1.01–1.05, p = 0.005) as well as an increase in the household poverty index (OR 1.29, 95% CI 1.13–1.48, p = 0.0002).

Conclusions/Significance

The 3.5-year progression of scarring among women in Kongwa, a formerly hyperendemic now turned hypoendemic district in central Tanzania, was high despite a low active trachoma prevalence. This suggests that the drivers of scarring progression are likely not related to on-going trachoma transmission in this district.

Trachoma, a chronic conjunctivitis caused by Chlamydia trachomatis, presents with follicles (trachomatous inflammation—follicular, TF) in children which leads to trachomatous conjunctival scarring (TS) in young adults. TS can progress to the in-turning of eyelashes, trachomatous trichiasis (TT) which places individuals at high risk of irreversible vision loss. Few studies to date have evaluated the progression of TS in communities that have recently transitioned to a low trachoma prevalence.

We studied the progression of TS in women in Kongwa, Tanzania a district that recently transitioned to a low prevalence of trachoma. We found that the overall cumulative progression of scarring was 35.3% over 3.5 years. The scarring progression rate observed is very similar to what we observed a decade prior in Kongwa when the trachoma prevalence was very high.

Our findings suggest that once scarring has developed it continues to progress irrespective of the current trachoma environment. This has potential ramifications for trachoma elimination efforts. An area could achieve the elimination of TF and still have to deal with scarring progression, which may lead to the development of TT. If this occurs: 1) elimination of TT will be delayed which will delay the overall elimination of trachoma as a public health problem, and 2) the limited resources available to elimination programs may need to be re-allocated.

Uptake of Trachoma Trichiasis Surgery and Associated Factors Among Trichiasis-Diagnosed Clients in Southern Tigray, Ethiopia

BACKGROUND

Trachoma is the most common infectious cause of blindness in the globe. Trichiasis surgery is the best treatment option for this disease. Despite efforts done to eliminate blinding trachoma, there is limited evidence on the surgical uptake of trachoma trichiasis in Ethiopia. This study was aimed to assess the uptake of trachoma trichiasis surgery in Southern Tigray, Ethiopia.

METHODS

Mixed cross-sectional study was employed among 409 participants. Study participants were selected using a consecutive sampling technique. Pretested and interviewer-administered data were collected using a structured questionnaire. Binary and multivariable logistic regression was done to identify associated factors. Adjusted odds ratios 95% CI was estimated to show the strength and direction. Variables with p-values <0.05 were considered statistically significant. For qualitative data, 4 focus group discussions were conducted with 40 participants and described by thematic analysis then triangulated with quantitative findings.

RESULTS

About 234 (57.9%, 95% CI: (53.2, 62.9)) participants utilized trachoma trichiasis surgery (TT). History of trachoma trichiasis (TT) for >2 years [AOR: 0.4, 95% CI: (0.22, 0.72)], informed about surgery program by health workers [AOR: 0.3, 95% CI: (0.13, 0.71)], history of TT surgery [AOR: 0.18, 95% CI: (0.05, 0.6)], absence of someone to care the family [AOR: 14, 95% CI: (6.9, 28.6)], companion [AOR: 8.9, 95% CI: (4.3, 18.3)], nearby health facility [AOR: 2.4, 95% CI: (1.1, 5.4)], work load [AOR: 8.8, 95% CI: (4.6, 17)], fear [AOR: 4.3, 95% CI: (1.8, 10)], and believing eye drop can treat TT [AOR: 3.9, 95% CI: (1.4, 11)] were significantly associated factors.

CONCLUSION

More than half of the participants accepted the TT surgical uptake. Strengthening community awareness on proper eye care, and effective treatment options, and addressing the negative attitude towards surgical treatment in the community are important measures to achieve the elimination target of trachoma.

Effect of repeated epilation for minor trachomatous trichiasis on lash burden, phenotype and surgical management willingness: A cohort study

Background

WHO endorsed the use of epilation as an alternative treatment to surgery for the management of both minor unoperated TT (UTT) and postoperative TT (PTT). However, some trachoma control programmes hesitated to implement epilation citing concerns that it would hamper TT surgical acceptance and result in larger numbers of and stiffer trichiatic eyelashes than the original TT lashes. We investigated the burden and phenotypes of post-epilation trichiatic eyelashes, and willingness to accept surgical management separately in unoperated and postoperative TT cases.

Methodology/Principal findings

We recruited cases with minor (≤5 eyelashes from the upper eyelid touching the eye or evidence of epilation in <1/3^rd of the upper eyelid) UTT (170) and PTT (169) from community-based screenings in Amhara Region, Ethiopia. Participants eyes were examined and data on present and future willingness to accept surgical management collected at baseline and every month for 6-months. Eyelashes touching the eye were counted and their phenotypes documented. Participants were trained on how to epilate. Epilation was done by the participants at home and by the examiner during follow-ups when requested by the participant. Follow-up rates were ≥97%. There was evidence of a significant reduction in the burden of trichiatic eyelashes in unoperated (mean difference = -0.90 [-1.11– -0.69]; RR = 0.50 [95% CI, 0.40–0.62]; p<0.0001), and postoperative (mean difference = -1.16 [-1.36– -0.95]; RR = 0.38 [95% CI, 0.31–0.48]; p<0.0001) cases 6-month after frequent epilation. Post-epilation trichiatic eyelashes at 6-months had higher odds of being thin (40.2% vs 55.8%, OR = 1.88 [95% CI, 1.21–2.93]; p = 0.0048), weak (39.8% vs 70.8%, OR = 3.68 [95%CI,2.30–5.88]; p<0.0001), and half-length (30.9% vs 43.3%, OR = 1.71 [1.09–2.68]; p = 0.020) than the pre-epilation trichiatic eyelashes in unoperated cases. There was a significant increase in the proportion of weak trichiatic eyelashes (OR = 1.99 [95% CI, 1.03–3.83; p = 0.039) in postoperative cases. In all 6 follow-up time points, 120/164 (73.2%) of unoperated and 134/163 (82.2%) of postoperative cases indicated that they would accept surgery if their trichiasis progressed.

Conclusions/Significance

In this study setting, frequent epilation neither hampers surgical acceptance nor results in more damaging trichiatic eyelashes than the pre-epilation lashes; and can be used as an alternative to the programmatic management of minor unoperated and postoperative TT cases.

Trachomatous Trichiasis (TT), the blinding stage of trachoma, ranges from few peripheral eyelashes touching the eye to all eyelashes scratching the cornea. TT is mainly treated with corrective eyelid surgery. However, not all TT cases require surgical correction, and some, particularly, those with few eyelashes decline surgery. Epilation, the repeated removal of eyelashes, is a very common clinical and traditional practice in many trachoma endemic settings. The World Health Organisation recommends that epilation can be offered as an alternative management strategy to surgery for patients with few eyelashes touching the eye or refusing surgery. However, some trachoma control programmes hesitated to implement epilation with the concern that it would hamper surgical acceptance and results in larger numbers of and stiffer eyelashes touching the eye than the original TT eyelashes. In this study, we explored if these concerns are true in epilating minor (≤5 eyelashes from the upper eyelid touching the eye or evidence of epilation in <1/3^rd of the upper eyelid) unoperated (170) and postoperative TT (169) cases. We found, in the contrary to these concerns, the post-epilation eyelashes touching the eye were less damaging being fewer in number, thinner, weaker and shorter than the pre-epilation eyelashes. In addition, the majority of both unoperated and postoperative cases indicated that they are willing to accept surgery if their trichiasis progressed.

Lamellar Tarsectomy Procedure In Major Trichiasis Of The Upper Lid

Aims

Evaluation of failure rate and outcomes between skin and muscle surgery and lamellar tarsectomy procedure in major trichiasis of the upper lid.

Design

Quasi-randomized clinical study.

Methods and subjects

One hundred individuals with major trichiasis of the upper lid were enrolled and assigned to either skin and muscle surgery (group A) or a lamellar tarsectomy procedure (group B). Participants were examined at 6 and 12 months. The primary outcome measure (failure rate) was the percentage of participants having five or more eyelashes touching the globe or having surgery performed at any follow-up time in both groups. The secondary outcomes included failure time and changes in both visual acuity and corneal opacity.

Results

Risk failure over 6 months was 40% in group A and 10% in group B. Absolute risk reduction was 30% (95% CI=14.08–45.92%). Cumulative risk failure over 12 months was 20% in group A and 0.00% in group B after the second intervention. Absolute risk reduction was 20% (95% CI=8.58–31.42%). The number needed to treat (NNT) was 3.3 patients (95% CI=2.2–7.1). The mean number of rubbing lashes was greater in the skin and muscle group than in the lamellar tarsectomy group for 6 and 12 month examinations (0.002, 0.005). The change in visual acuity between the two groups was not significant. Recurrent trichiasis was noticed earlier, 6 weeks after surgery, in the skin and muscle group participants, and later, 3 months after surgery, in the lamellar tarsectomy group participants.

Conclusion

The lamellar tarsectomy procedure is a good choice for management of major trichiasis of the upper lid. The subjective symptoms and lid margin conjunctivalization were improved in lamellar tarsectomy participants. Absence of new corneal opacity or a change in existing corneal opacification was noticed at the 12 months follow-up study.

Fluorometholone 0.1% as Ancillary Therapy for Trachomatous Trichiasis Surgery: Randomized Clinical Trial

PURPOSE

To assess the hypothesis that fluorometholone 0.1% eye drops are safe and effective as adjunctive therapy for trachomatous trichiasis (TT) surgery; determining the most promising dose.

DESIGN

Randomized, placebo-controlled, double-masked parallel dose-ranging clinical trial.

METHODS

Patients undergoing upper lid TT surgery at a rural Ethiopian hospital were randomized to fluorometholone 0.1% twice daily for 4 weeks, 4 times daily for 4 weeks, 4 times daily for 8 weeks, or matching frequency placebo in a 3:1:3:1:3:1 ratio for 1 eye. Randomization was stratified by TT severity (1-4 vs ≥5 lashes touching the globe). Safety outcomes (intraocular pressure [IOP] elevation, cataract, and other dose-limiting toxicities) and postoperative TT incidence were assessed over 1 year.

RESULTS

Subjects randomized were 39:13:39:13:38:13 in the respective groups, and 1 subject in the 8-weeks fluorometholone group was withdrawn. Of 154 subjects, 148 (96.1%) completed 1 year's follow-up. Among 76 eyes receiving fluorometholone 4 times daily, 1 developed IOP elevation ≥ 30 mm Hg (to 37 mm Hg) and 1 had an allergic reaction attributed to the study drug; each resolved upon drug cessation without sequelae. No cataract or other dose-limiting toxicity events occurred. Postoperative TT within 1 year occurred in 29.3% of placebo eyes vs 17.7%, 19.6%, and 23.2% among the respective fluorometholone groups (P = .29 comparing placebo vs all active treatments combined).

CONCLUSIONS

The results suggest fluorometholone 0.1% is likely to be safe and efficacious to reduce postoperative TT following TT surgery, and 1 drop twice daily for 4 weeks is the most promising dose. Confirmation in a full-scale clinical trial is needed before programmatic implementation.

Oral doxycycline for the prevention of postoperative trachomatous trichiasis in Ethiopia: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Trachomatous trichiasis is treated surgically to prevent sight loss. Unfavourable surgical outcomes remain a major challenge. We investigated the hypothesis that doxycycline might reduce the risk of postoperative trichiasis following surgery in patients with trachomatous trichiasis through anti-matrix metalloproteinase and anti-inflammatory activity.

METHODS

In this randomised, double-blind, placebo-controlled trial, adults (aged >18 years) with upper lid trachomatous trichiasis in association with tarsal conjunctive scarring were recruited through community-based screening and surgical outreach campaigns in Ethiopia. Individuals who had previously had eyelid surgery were excluded. Participants were randomly assigned (1:1), with random block sizes of four or six, to receive oral doxycycline (100 mg once a day) or placebo for 28 days immediately after trichiasis surgery. Randomisation was stratified by surgeon. Patients, investigators, surgeons, and all other study team members were masked to study group allocation and treatment. Participants were examined at 10 days, and 1, 6, and 12 months after surgery. The primary outcome was the cumulative proportion of individuals who developed postoperative trichiasis by 12 months. Primary analyses were done in all participants who attended at least one of the four follow-up assessments. Safety analyses were done in all participants who attended either the 10 day or 1 month follow-up assessments. This trial is registered with the Pan African Clinical Trials Registry, number PACTR201512001370307.

FINDINGS

Between Dec 21, 2015, and April 6, 2016, 1000 patients with trichiasis were enrolled and randomly assigned to treatment (499 patients to doxycycline, 501 patients to placebo). All but one participant attended at least one follow-up assessment. Thus, 999 participants were assessed for the primary outcome: 498 in the doxycycline group and 501 in the placebo group. By month 12, 58 (12%) of 498 patients in the doxycycline group and 62 (12%) of 501 patients in the placebo group had developed postoperative trichiasis (adjusted odds ratio 0·91, 95% CI 0·61 to 1·34, p=0·63), with a risk difference of -0·5% (-4·5% to 3·5%). Significantly more patients in the doxycycline group had an adverse event than in the placebo group (18 [4%] of 498 vs six [1%] of 501; odds ratio 3·09, 95% CI 1·21-7·84; p=0·02). The most frequent adverse events in the doxycycline group were gastritis symptoms (n=9), constipation (n=4), and diarrhoea (n=4).

INTERPRETATION

Doxycycline did not reduce the risk of postoperative trichiasis and is therefore not indicated for the improvement of outcomes following trachomatous trichiasis surgery. Surgical programmes should continue to make efforts to strengthen surgical training and supervision to improve outcomes.

FUNDING

The Wellcome Trust.

Blinding Trachoma: Systematic Review of Rates and Risk Factors for Progressive Disease

BACKGROUND

Sight loss from trachoma is the end result of a scarring disease process starting in early childhood and characterised by repeated episodes of conjunctival inflammation (active trachoma). Subsequently, the conjunctiva becomes scarred, causing the eyelashes to turn inwards and scratch the cornea (trichiasis), damaging the corneal surface and leading to corneal opacification and visual impairment. It is thought that this process is initiated and driven by repeated infection with Chlamydia trachomatis. We review published longitudinal studies to re-examine the disease process, its progression rates and risk factors.

METHODOLOGY/PRINCIPAL FINDINGS

We searched PubMed for studies presenting incidence and progression data for the different stages of trachoma natural history. We only included studies reporting longitudinal data and identified 11 publications meeting this criterion. The studies were very heterogeneous in design, disease stage, duration, size and location, precluding meta-analysis. Severe conjunctival inflammation was consistently associated with incident and progressive scarring in five studies in which this was examined. One study reported an association between C. trachomatis infection and incident scarring. No studies have yet demonstrated an association between C. trachomatis infection and progressive scarring. Several studies conducted in regions with low prevalence active disease and C. trachomatis infection found evidence of on-going scarring progression.

CONCLUSIONS/SIGNIFICANCE

Overall, there are few longitudinal studies that provide estimates of progression rates and risk factors, reflecting the challenges of conducting such studies. Our understanding of this disease process and the long-term impact of control measures is partial. Intense conjunctival inflammation was consistently associated with scarring, however, direct evidence demonstrating an association between C. trachomatis and progression is limited. This suggests that on-going chlamydial reinfection may not be mandatory for progression of established scarring, indicating that sight threatening trichiasis may continue to evolve in older people in formerly endemic populations, that will require service provision for years after active disease is controlled.

Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria: The Role of Environmental and Climatic Risk Factors on the Distribution of Disease

The distribution of trachoma in Nigeria is spatially heterogeneous, with large-scale trends observed across the country and more local variation within areas. Relative contributions of individual and cluster-level risk factors to the geographic distribution of disease remain largely unknown. The primary aim of this analysis is to assess the relationship between climatic factors and trachomatous trichiasis (TT) and/or corneal opacity (CO) due to trachoma in Nigeria, while accounting for the effects of individual risk factors and spatial correlation. In addition, we explore the relative importance of variation in the risk of trichiasis and/or corneal opacity (TT/CO) at different levels. Data from the 2007 National Blindness and Visual Impairment Survey were used for this analysis, which included a nationally representative sample of adults aged 40 years and above. Complete data were available from 304 clusters selected using a multi-stage stratified cluster-random sampling strategy. All participants (13,543 individuals) were interviewed and examined by an ophthalmologist for the presence or absence of TT and CO. In addition to field-collected data, remotely sensed climatic data were extracted for each cluster and used to fit Bayesian hierarchical logistic models to disease outcome. The risk of TT/CO was associated with factors at both the individual and cluster levels, with approximately 14% of the total variation attributed to the cluster level. Beyond established individual risk factors (age, gender and occupation), there was strong evidence that environmental/climatic factors at the cluster-level (lower precipitation, higher land surface temperature, higher mean annual temperature and rural classification) were also associated with a greater risk of TT/CO. This study establishes the importance of large-scale risk factors in the geographical distribution of TT/CO in Nigeria, supporting anecdotal evidence that environmental conditions are associated with increased risk in this context and highlighting their potential use in improving estimates of disease burden at large scales.

Trichiasis (TT) and corneal opacity (CO) are chronic stages of trachoma, which remains an important cause of blindness. This study used multilevel spatial models to investigate risk factors for TT/CO in Nigeria, including data for more than 13,500 adults aged 40 years and above collected in the 2007 National Blindness and Visual Impairment survey. Individual-level risk factors were consistent with those identified in other studies, including a higher risk in females, older individuals and those with lower socioeconomic status. After controlling for these factors, there was evidence that a number of environmental and climatic factors are associated with the distribution of TT/CO in Nigeria. These findings establish for the Nigerian context the importance of risk factors at different scales for the later stages of trachoma, supporting anecdotal evidence that hotter, drier environmental conditions are associated with increased risk.

Patients' Perceptions of Trichiasis Surgery: Results from the Partnership for Rapid Elimination of Trachoma (PRET) Surgery Clinical Trial

Purpose: While quality of life surveys have been conducted in trachomatous trichiasis (TT) surgery populations, little is known about patients’ perceptions of the surgical experience and outcomes.

Methods: We interviewed a subset of Partnership for the Rapid Elimination of Trachoma (PRET) surgery trial participants 24 months after surgery. Questions focused on current ocular symptoms, perceived daily functioning, physical appearance, and overall perception of surgery. We stratified participants based on surgical outcomes: normal upper eyelid, postoperative TT, or eyelid contour abnormality (ECA) in one or both eyelids. We compared responses between sexes and surgical outcome groups using contingency tables and Fisher’s exact tests.

Results: A total of 483 individuals participated and 86% were very satisfied with surgery results; 96% reported ocular symptom improvement. Participants with moderate to severe ECA or postoperative TT were more likely to report current ocular problems than those with normal eyelids (46% and 58% vs 34%, respectively; p = 0.01 for each comparison). The most common symptom among participants with moderate to severe postoperative TT was feeling lashes touching (blurred vision was the most common among participants with moderate to severe ECA). Overall, 83% stated surgery improved daily life; participants with ECA were less likely to report improvement than others (p = 0.002). Participants who had moderate or severe postoperative TT were least likely to state that they would undergo repeat surgery (80%), followed by participants with ECA (86%).

Conclusions: Postoperative TT and ECA both reduced satisfaction with surgery, but appeared to influence different aspects of life. Improving surgical outcomes both by reducing recurrence rates and limiting ECAs are essential.

Trachoma

Trachoma is the most common infectious cause of blindness. Repeated episodes of infection with Chlamydia trachomatis in childhood lead to severe conjunctival inflammation, scarring, and potentially blinding inturned eyelashes (trichiasis or entropion) in later life. Trachoma occurs in resource-poor areas with inadequate hygiene, where children with unclean faces share infected ocular secretions. Much has been learnt about the epidemiology and pathophysiology of trachoma. Integrated control programmes are implementing the SAFE Strategy: surgery for trichiasis, mass distribution of antibiotics, promotion of facial cleanliness, and environmental improvement. This strategy has successfully eliminated trachoma in several countries and global efforts are underway to eliminate blinding trachoma worldwide by 2020.

The limits of medical interventions for the elimination of preventable blindness

Background: Health authorities are working toward the global elimination of trachoma by the year 2020 with actions focused on the World Health Organization SAFE strategy (surgery of trichiasis, antibiotics, face washing and environmental changes) with emphasis on hygienist approaches for education.

Objectives: The present survey was performed to assess the sustainability of the SAFE strategy 3 years after trachoma was eliminated from 6 villages.

Methods: In February 2013 a rapid trachoma assessment was conducted in 6 villages of Kolofata’s district, Extreme north Region, Cameroon, where trachoma was eliminated in 2010. A total of 300 children (1–10 years) from 6 villages were examined by trained staff.

Results: The prevalence of active trachoma (children aged > 1 and < 10 years) in 2013 was 15% and in at least 25% was observed absence of face washing and flies in their eyes and nose. Income level, quality of roads, hygiene, and illiteracy were similar in all the villages; they did not change between 2010 and 2013 and could not be analyzed as independent risk factors.

Discussion: The heterogeneity of methods described for clinical trials makes it inappropriate to conduct meta-analysis for the present and for other SAFE-related trials. The results obtained after implementation the SAFE strategy (recurrence) reveal that the causes (infectious agents and dirtiness) and effects (illness) were not connected by illiterate people living under conditions of extreme poverty. So far, antibiotics, surgery and hygiene education are insufficient for the sustainability of trachoma elimination and highlight that hypothetic-deductive processes seem not operational after implementing the awareness campaigns. Trachoma recurrence detected in 2013 in sedentary populations of Kolofata receiving efficacious treatments against Chlamydia sp. suggest that the elimination goals will be delayed if strategies are limited to medical actions. Restricting efforts to repeated pharmacological and surgical interventions for people infected with susceptible bacteria could be understood as the hidden side of a passive attitude toward basic education actions.

The outcome of trachomatous trichiasis surgery in Ethiopia: risk factors for recurrence

Background

Over 1.2 million people are blind from trachomatous trichiasis (TT). Lid rotation surgery is the mainstay of treatment, but recurrence rates can be high. We investigated the outcomes (recurrence rates and other complications) of posterior lamellar tarsal rotation (PLTR) surgery, one of the two most widely practised TT procedures in endemic settings.

Methodology/Principal Findings

We conducted a two-year follow-up study of 1300 participants who had PLTR surgery, conducted by one of five TT nurse surgeons. None had previously undergone TT surgery. All participants received a detailed trachoma eye examination at baseline and 6, 12, 18 and 24 months post-operatively. The study investigated the recurrence rates, other complications and factors associated with recurrence. Recurrence occurred in 207/635 (32.6%) and 108/641 (16.9%) of participants with pre-operative major (>5 trichiatic lashes) and minor (<5 lashes) TT respectively. Of the 315 recurrences, 42/315 (3.3% overall) had >5 lashes (major recurrence). Recurrence was greatest in the first six months after surgery: 172 cases (55%) occurring in this period. Recurrence was associated with major TT pre-operatively (OR 2.39, 95% CI 1.83–3.11), pre-operative entropic lashes compared to misdirected/metaplastic lashes (OR 1.99, 95% CI 1.23–3.20), age over 40 years (OR 1.59, 95% CI 1.14–2.20) and specific surgeons (surgeon recurrence risk range: 18%–53%). Granuloma occurred in 69 (5.7%) and notching in 156 (13.0%).

Conclusions/Significance

Risk of recurrence is high despite high volume, highly trained surgeons. However, the vast majority are minor recurrences, which may not have significant corneal or visual consequences. Inter-surgeon variation in recurrence is concerning; surgical technique, training and immediate post-operative lid position require further investigation.

Trachoma is the most common infectious cause of blindness worldwide. It causes trichiasis (inturning of the eyelashes to touch the eye), which can cause visual loss. Trachomatous trichiasis (TT) affects over eight million people, 1.2 of whom live in Ethiopia – the most affected country worldwide. Surgery is the mainstay of treatment for TT. However, results of surgery in the field are often very mixed. We investigated the surgical outcomes of one of the two most widely used surgical techniques (posterior lamellar rotation), in 1300 individuals in the Amhara Region of Ethiopia. We found that recurrence occurred frequently: 315/1276 (24.7%) participants. However, recurrence was rarely severe (greater than 5 lashes): 42 participants (3.3%). Recurrence occurred much more frequently in participants who had severe pre-operative disease and with specific surgeons. The high recurrence rates and inter-surgeon variation is concerning. Further research will be required to investigate factors such as surgical technique, surgeon training and immediate post-operative lid position, in order to improve surgical outcomes.

Evaluation of community-based trichiasis surgery in Northwest Ethiopia

BACKGROUND

Surgery to correct trachomatous trichiasis (TT) is recommended to prevent blindness caused by trachoma. This study evaluated the outcomes of community-based trichiasis surgery with absorbable sutures, conducted in Amhara Regional State, Ethiopia.

METHODS

A simple random sample of 431 patients was selected from surgical campaign records of which 363 (84.2%) were traced and enrolled into the study. Participants were interviewed and examined for trichiasis recurrence, complications of TT surgery and corneal opacity. Multilevel logistic regression models were used to explore the associations between trichiasis recurrence, corneal opacity and explanatory variables at the eye level.

RESULTS

The prevalence of trichiasis recurrence was 9.4% (95% Confidence Interval [CI] 6.6-12.8) and corneal opacity was found in 14.3% (95% CI 10.9-18.3) of the study participants. The proportion of participants with complications of TT surgery was: granuloma 0.6% (95% CI 0.1-2.0); lid closure defects 5.5% (95% CI 3.4-8.4) and lid notching 16.8% (95% CI 13.1-21.1). No factors were identified for trichiasis recurrence. Corneal opacity was associated with increased age (Ptrend=0.001), more than 12 months post surgery (OR=2.7; 95%CI 1.3-5.6), trichiasis surgery complications (OR=2.9; 95%CI 1.4-5.9) and trichiasis recurrence (OR=2.5; 95%CI 1.0-6.3).

CONCLUSION

Prevalence of recurrent trichiasis and granuloma were lower than expected but higher for lid closure defects and lid notching. The majority of the participants reported satisfaction with the trichiasis surgery they had undergone. The findings suggest that recurrence of trichiasis impacts on the patients' risk of developing corneal opacity but longitudinal studies are required to confirm this.

Will the SAFE strategy be sufficient to eliminate trachoma by 2020? Puzzlements and possible solutions

Since the inception of (the Global Elimination of Blinding Trachoma) GET 2020 in 1997 and the implementation of the SAFE strategy a year later, much progress has been made toward lowering the prevalence of trachoma worldwide with elimination of the disease in some countries. However, high recurrence of trichiasis after surgery, difficulty in controlling the reemergence of infection after mass distribution of azithromycin in some communities, the incomplete understanding of environment in relation to the disease, and the difficulty in establishing the prevalence of the disease in low endemic areas are some of the issues still facing completion of the GET 2020 goals. In this narrative review, literature was searched from 1998 to January 2013 in PubMed for original studies and reviews. Reasons for these ongoing problems are discussed, and several suggestions are made as avenues for exploration in relation to improving the SAFE strategy with emphasis on improving surgical quality and management of the mass treatment with antibiotics. In addition, more research needs to be done to better understand the approach to improve sanitation, hygiene, and environment. The main conclusion of this review is that scale-up is needed for all SAFE components, and more research should be generated from communities outside of Africa and Asia.

Trachoma: protective and pathogenic ocular immune responses to Chlamydia trachomatis

Trachoma, caused by Chlamydia trachomatis (Ct), is the leading infectious blinding disease worldwide. Chronic conjunctival inflammation develops in childhood and leads to eyelid scarring and blindness in adulthood. The immune response to Ct provides only partial protection against re-infection, which can be frequent. Moreover, the immune response is central to the development of scarring pathology, leading to loss of vision. Here we review the current literature on both protective and pathological immune responses in trachoma. The resolution of Ct infection in animal models is IFNγ-dependent, involving Th1 cells, but whether this is the case in human ocular infection still needs to be confirmed. An increasing number of studies indicate that innate immune responses arising from the epithelium and other innate immune cells, along with changes in matrix metalloproteinase activity, are important in the development of tissue damage and scarring. Current trachoma control measures, which are centred on repeated mass antibiotic treatment of populations, are logistically challenging and have the potential to drive antimicrobial resistance. A trachoma vaccine would offer significant advantages. However, limited understanding of the mechanisms of both protective immunity and immunopathology to Ct remain barriers to vaccine development.

The burden of trachoma in South Sudan: assessing the health losses from a condition of graded severity

Introduction

Trachoma is a disease that can lead to visual impairment and ultimately blindness. Previous estimates of health losses from trachoma using the Global Burden of Disease methodology have not, however, included the stage prior to visual impairment. We estimated the burden of all stages of trachoma in South Sudan and assessed the uncertainty associated with the severity and duration of stages of trachoma prior to full blindness.

Methods

The prevalence of trachoma with normal vision, low vision and blindness in the Republic of South Sudan has been estimated previously. These estimates were used to model the incidence and duration of the different stages employing DISMOD II. Different assumptions about disability weights and duration were used to estimate the Years Lived with Disability (YLD).

Results

We have estimated the total burden of trachoma in South Sudan to be between 136,562 and 163,695 YLD and trichiasis with normal vision contributes between 5% and 21% of the total depending on the disability weight applied. Women experience more of this burden than men. The sensitivity of the results to different assumptions about the disability weights is partly dependent upon the assumed duration of the different disease states.

Interpretation

A better understanding of the natural history of trachoma is critical for a more accurate burden estimate.

Trachoma is an infectious disease that is endemic to the Republic of South Sudan. In the absence of appropriate treatment recurrent re-infection in an individual will lead to progressively severe states of trachoma, eventually leading to the loss of visual acuity and finally blindness. Here we distinguish between three separate states of disease: trachoma with normal vision, trachoma with low vision and trachoma with blindness. The first of these states, trachoma with normal vision, is the least severe and the impact of this state on a population has not been well investigated. Trachoma, even before any loss of vision, comes with a great deal of pain and social consequences, and thus disability. In this study we employ data from South Sudan and estimate the burden caused by trachoma with normal vision for the first time. In doing so, we also reveal the extent of the gaps in our knowledge surrounding the natural history of trachoma and highlight areas of research that require urgent attention.

Trachomatous trichiasis and its management in endemic countries

Trichiasis is the sight-threatening consequence of conjunctival scarring in trachoma, the most common infectious cause of blindness worldwide. Trachomatous trichiasis is the result of multiple infections from childhood with Chlamydia trachomatis, which causes recurrent chronic inflammation in the tarsal conjunctiva. This produces conjunctival scarring, entropion, trichiasis, and ultimately blinding corneal opacification. The disease causes painful, usually irreversible sight loss. Over eight million people have trachomatous trichiasis, mostly those living in poor rural communities in 57 endemic countries. The global cost is estimated at US$ 5.3 billion. The WHO recommends surgery as part of the SAFE strategy for controlling the disease.We examine the principles of clinical management, treatment options, and the challenging issues of providing the quantity and quality of surgery that is needed in resource-poor settings.

Changes in the prevalence of visual impairment due to blinding trachoma in Sichuan province, China: a comparative study between 1987 and 2006

PURPOSE

The aim of this study was to assess the changes in the prevalence of visual impairment due to blinding trachoma in Sichuan, China between 1987 and 2006.

METHODS

Over 125,000 residents of Sichuan province participated in the National Sample Survey on Disabilities, conducted in both 1987 and 2006. Changes in the prevalence of visual impairment due to blinding trachoma were analyzed while accounting for other factors including gender, age and residence (urban vs. rural).

RESULTS

In 1987, blinding trachoma ranked second among the eight major visual impairment causes assessed with a prevalence of 172.9 (95% CI: 152.2-196.6) per 100,000, while in 2006 it ranked eighth with a prevalence of 58.1 (95% CI: 45.5-73.0) per 100,000. The prevalence in 2006 decreased significantly compared to 1987 in both rural and urban areas, as well as in both genders. Furthermore, in both 1987 and 2006, visual impairment due to blinding trachoma tended to be concentrated among individuals over 40, although it was also seen in young people.

CONCLUSION

In the past 20 years, the prevalence and percentage of visual impairment due to blinding trachoma was significantly reduced in Sichuan province, and we anticipate a further decrease in the future.

Absorbable versus silk sutures for surgical treatment of trachomatous trichiasis in Ethiopia: a randomised controlled trial

BACKGROUND

Trachoma causes blindness through an anatomical abnormality called trichiasis (lashes touching the eye). Trichiasis can recur after corrective surgery. We tested the hypothesis that using absorbable sutures instead of silk sutures might reduce the risk of recurrent disease among patients with major trichiasis in a randomised trial.

METHODS AND FINDINGS

1,300 individuals with major trichiasis from rural villages in the Amhara Region of Ethiopia were recruited and assigned (1:1) by computer-generated randomisation sequence to receive trichiasis surgery using either an absorbable suture (polyglactin-910) or silk sutures (removed at 7-10 days) in an otherwise identical surgical technique. Participants were examined every 6 months for 2 years by clinicians masked to allocation. The primary outcome measure was recurrent trichiasis (≥one lash touching the eye) at 1 year. There was no difference in prevalence of recurrent trichiasis at 1 year (114 [18.2%] in the absorbable suture group versus 120 [19.7%] in the silk suture group; odds ratio = 0.90, 95% CI 0.68-1.20). The two groups also did not differ in terms of corneal opacification, visual acuity, conjunctival inflammation, and surgical complications.

CONCLUSIONS

There was no evidence that use of absorbable polyglactin-910 sutures was associated with a lower prevalence of trichiasis recurrence at 1 year postsurgery than silk sutures. However, from a programmatic perspective, polyglactin-910 offers the major advantage that patients do not have to be seen soon after surgery for suture removal. The postoperative review after surgery using absorbable polyglactin-910 sutures can be delayed for 3-6 months, which might allow us to better determine whether a patient needs additional surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00522860.

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.

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.

The determinants of trichiasis recurrence differ at one and two years following lid surgery in Vietnam: A community-based intervention study

Aim

To compare determinants for recurrence of trichiasis at one and two years following lid surgery in Vietnam.

Study Design

Community-based intervention study.

Methods

This study was carried out between 2000 and 2003 in four trachoma-endemic districts of Vietnam. Trained trichiasis surgeons performed modified Cuenod Nataf lid surgery on 648 eyes of 472 patients with Trachomatous trichiasis (TT). Trained investigators collected information on ocular and lid status before surgery and at one and two years following surgery. Trichiasis recurrence was calculated after adjusting for one or both eyes of each operated individual.

Results

Fifty-six eyes developed recurrence at one year with adjusted prevalence of 8.8% (95% CI 6.60-11.01). One hundred and one eyes [15.9% (95% CI 13.04-18.72)] had recurrence two years following surgery. Female gender, older age group, study area, severe grade of trachomatous scarring (TS), past history of lid surgery, postoperative suture adjustment and surgeon were risk factors for recurrence at the end of one year. Study area and previous lid surgery were risk factors for recurrence in the second year. Recurrence at one year could be predicted if study area and severity of Trachomatous Scarring (TS) are known.

Conclusions

One and two year recurrence rates with modified Cuenod Nataf lid surgeries for TT in Vietnam were acceptably low. Early recurrence could be reduced by proper case selection. However, late recurrence seems to be dependent on interaction of risk factors. Only age of the patient was the reliable predictor of recurrence.

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.

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.

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.

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.

What will happen if we do nothing to control trachoma: health expectancies for blinding trachoma in southern Sudan

Background

Uncontrolled trachoma is a leading cause of blindness. Current global trachoma burden summary measures are presented as disability adjusted life years but have limitations due to inconsistent methods and inadequate population-based data on trachomatous low vision and blindness. We aimed to describe more completely the burden of blinding trachoma in Southern Sudan using health expectancies.

Methodology/Principal Findings

Age and gender specific trachomatous trichiasis (TT) prevalence was estimated from 11 districts in Southern Sudan. The distribution of visual acuity (VA) in persons with TT was recorded in one district. Sudan life tables, TT prevalence, and VA were used to calculate Trichiasis Free Life Expectancy (TTFLE) and Trichiasis Life Expectancy (TTLE) using the Sullivan method. TTLE was broken down by VA to derive TTLE with normal vision, TTLE with low vision, and TTLE with blindness. Total life expectancy at birth in 2001 was 54.2 years for males and 58.1 for females. From our Sullivan models, trichiasis life expectancy at the age of 5 years was estimated to be 7.0 (95% confidence interval [CI] = 6.2–7.8) years (12% [95% CI = 11–14] of remaining life) for males and 10.9 (95% CI = 9.9–11.9 ) years (18% [95% CI = 16–20] of remaining life) for females. Trichiasis life expectancy with low vision or blindness was 5.1 (95% CI = 3.9–6.4) years (9% [95% CI = 7–11] of remaining life) and 7.6 (95% CI = 6.0–9.1) years (12% [95% CI = 10–15] of remaining life) for males and females, respectively. Women were predicted to live longer and spend a greater proportion of their lives with disabling trichiasis, low vision, and blindness compared to men.

Conclusions

The study shows the future burden associated with doing nothing to control trachoma in Southern Sudan, that is, a substantial proportion of remaining life expectancy spent with trichiasis and low vision or blindness for both men and women, with a disproportionate burden falling on women.

Summary measures of population health attempt to express disease burden in terms of a common “currency” and are useful in establishing public health priorities. Disability adjusted life years (DALYs), a health gap measure, have previously been used to estimate burden due to trachoma; however, their methods and results have limitations. This study demonstrates the application of the health expectancies to estimate burden due to trachoma. The study illustrates the future burden associated with doing nothing to control trachoma in Southern Sudan: a substantial proportion of remaining life expectancy spent with trichiasis and low vision or blindness for both men and women, with a disproportionate burden falling on women. The results presented are intuitively meaningful for policy makers and a non-technical audience and compare favourably with other indicators such as mortality and incidence rates or DALYs, which are not generally easily understood. Unless action is taken by further delivery of trachoma control interventions, then populations in Southern Sudan can expect to spend a substantial proportion of their life with low vision or blindness due to trachoma.

Determinants of uptake of surgical treatment for trachomatous trichiasis in North Ethiopia

BACKGROUND

Surgery for trachomatous trichiasis prevents blindness. However people still decline surgery despite the availability of services in nearby health facilities.

OBJECTIVES

To assess what proportion of cases of trichiasis had surgical treatment and to investigate the determinants of uptake of surgery.

METHODS

Eight villages in Enebse Sarmidir district of Amhara Region-Ethiopia were randomly selected and all self-reported cases of trichiasis were approached. Both operated and un-operated trichiasis cases were interviewed using structured questionnaires.

RESULT

The study employed a case control study design with patients with untreated trichiasis being cases (135) and those operated, controls (141). The main reasons given for not having surgery were burden of household tasks, indirect cost of surgery, lack of companion and fear of surgery. Uptake of surgery was found to rise with duration of illness (Chi Square for trend = 26.62, P < 0.05). Longer walking distance (more than one hour) to the nearby health facility was a negative predictor of uptake of surgical treatment (adjusted odd ratio 0.31, 95% confidence interval 0.15-0.67).

CONCLUSION

Behavior change communication interventions targeted on early uptake of surgery are very important. Village-based surgical service provision may be worthwhile in settings of high blinding trachoma burden.

Identification of novel single nucleotide polymorphisms in inflammatory genes as risk factors associated with trachomatous trichiasis

Background

Trachoma is the leading preventable cause of global blindness. A balanced Th1/Th2/Th3 immune response is critical for resolving Chlamydia trachomatis infection, the primary cause of trachoma. Despite control programs that include mass antibiotic treatment, reinfection and recurrence of trachoma are common after treatment cessation. Furthermore, a subset of infected individuals develop inflammation and are at greater risk for developing the severe sequela of trachoma known as trachomatous trichiasis (TT). While there are a number of environmental and behavioral risk factors for trachoma, genetic factors that influence inflammation and TT risk remain ill defined.

Methodology/Findings

We identified single nucleotide polymorphisms (SNP) in 36 candidate inflammatory genes and interactions among these SNPs that likely play a role in the overall risk for TT. We conducted a case control study of 538 individuals of Tharu ethnicity residing in an endemic region of Nepal. Trachoma was graded according to World Health Organization guidelines. A linear array was used to genotype 51 biallelic SNPs in the 36 genes. Analyses were performed using logic regression modeling, which controls for multiple comparisons. We present, to our knowledge, the first significant association of TNFA (-308GA), LTA (252A), VCAM1 (-1594TC), and IL9 (T113M) polymorphisms, synergistic SNPs and risk of TT. TT risk decreased 5 times [odds ratio = 0.2 (95% confidence interval 0.11.–0.33), p = 0.001] with the combination of TNFA (-308A), LTA (252A), VCAM1 (-1594C), SCYA 11 (23T) minor allele, and the combination of TNFA (-308A), IL9 (113M), IL1B (5′UTR-T), and VCAM1 (-1594C). However, TT risk increased 13.5 times [odds ratio = 13.5 (95% confidence interval 3.3–22), p = 0.001] with the combination of TNFA (-308G), VDR (intron G), IL4R (50V), and ICAM1 (56M) minor allele.

Conclusions

Evaluating genetic risk factors for trachoma will advance our understanding of disease pathogenesis, and should be considered in the context of designing global control programs.

Risk factors for trachomatous trichiasis in children: cross-sectional household surveys in Southern Sudan

We have previously documented blinding trachoma to be a serious public health problem in Southern Sudan, with an unusually high prevalence of trachomatous trichiasis (TT) among children. We aimed to investigate risk factors for TT in children in Southern Sudan. Cross-sectional surveys were undertaken in 11 districts between 2001 and 2006, and eligible participants were examined for trachoma signs. Risk factors were assessed through interviews and observations. Using logistic regression, associations between TT in children and potential risk factors were investigated. In total, 11155 children aged 1-14 years from 3950 households were included in the analysis. Overall prevalence of TT was 1.5% (95% CI 1.1-2.1). Factors independently associated with increased odds of TT in children aged 1-14 years were: increasing age (P(trend)<0.001); female gender (odds ratio=1.5; 95% CI 1.1-2.1); increasing proportion of children in the household with trachomatous inflammation-intense (TI) (P(trend)=0.002); and increasing number of adults in the household with TT (P(trend)<0.001). Our study revealed risk factors for TT in children consistent with those previously reported for TT in adults. While the associations of TT in children with TI in siblings and TT in adult relatives merit further investigation, there is an urgent need for trachoma prevention interventions and trichiasis surgery services that are tailored to cater for young children in Southern Sudan.

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.

The epidemiology of low vision and blindness associated with trichiasis in southern Sudan

Background

We investigated vision status associated with trachomatous trichiasis (TT) and explored age-sex patterns of low vision and blindness associated with trichiasis in Mankien district of southern Sudan where trachoma prevention and trichiasis surgery were absent.

Methods

A population based survey was undertaken and eligible persons underwent eye examination. Visual acuity (VA) was tested using Snellen E chart and persons with TT identified. Vision status was defined using the WHO categories of visual impairment based on presenting VA: normal vision (VA ≥ 6/18 in better eye); low vision (VA < 6/18 but ≥ 3/60 in better eye); and blindness (VA < 3/60 in better eye). An ordinal logistic regression model was fitted and age/sex specific distribution of vision status predicted.

Results

Overall 341/3,567 persons examined had any TT. Analysis was based on 319 persons, 22 persons were excluded: 20 had both TT and cataract; and 2 had missing VA data. Of the 319 persons: 158(49.5%) had trichiasis-related corneal opacity (CO); bilateral TT and bilateral CO were found in 251(78.7%) and 110 (34.5%), respectively; 146 (45.8%) had low vision or blindness; the ratio of low vision to blindness was 3.2:1; and no sex differences were observed. In our model the predicted distribution of vision status was: normal vision, 53.9% (95% CI 50.9–56.9); low vision, 35.3% (95% CI 33.3–37.2); and blindness, 10.9% (95% CI 9.7–12.0).

Conclusion

We have reported severe trichiasis and high prevalence of vision loss among persons with trichiasis. Our survey showed that almost 1 in 20 of the entire population suffered low vision or blindness associated with trachoma. The need for trichiasis surgery, trachoma prevention services, and rehabilitation of the blind is acute.

Trachoma: transmission, infection, and control

Mass antibiotic treatment and facial cleanliness are central to WHO's strategy for the elimination of blindness caused by trachoma. Recent studies have highlighted the heterogeneous response of communities to mass treatment and the complex relation between infection with Chlamydia trachomatis and clinical disease. It is important to be able to explain these findings to predict and maximise the effect of treatment on active trachoma disease and blindness in the community. Here we review the immunobiology of trachoma and provide a simple conceptual model of disease pathogenesis. We show how incorporating this model into a mathematical framework leads to an explanation of the observed community distribution of infection, bacterial load, and disease with age. The predictions of the model and empirical data show some differences that underscore the importance of individual heterogeneity in response to infection. The implications of disease transmission and pathogenesis for trachoma control programmes are discussed.

Recurrence of trachomatous trichiasis 17 years after bilamellar tarsal rotation procedure

PURPOSE

In 1989, World Health Organization consultant operated on trachomatous trichiasis (TT) cases in Dhakhiliya region of Oman. We evaluated their current ocular status.

DESIGN

This was an historic cohort study.

METHODS

This study was conducted in an in-house setting. Ninety-one patients with TT who underwent operation by the bilamellar tarsal rotation procedure (BTR) were our study population. Their preoperative, operative, and immediate postoperative data were retrieved from the register. Staff members located and visited these patients. They examined the eyes and determined their visual, TT, and corneal status. They interviewed participants with a close-ended questionnaire to assess the quality of life and satisfaction for the TT services that were offered.

RESULTS

Sixty-three patients could be followed. Among 72 eyes that had undergone operation 17 years earlier, the recurrence rate was 47.2% (95% CI, 35.7-58.8). In 21 unoperated eyes (55%), TT was noted. The association of TT recurrence to age, gender, type of TT, conjunctivitis, and active trachoma was tested. The BTR for minor trichiasis was the risk factor for recurrence of TT (adjusted odds ratio, 3.9; 95% CI, 1.4-10.8).

CONCLUSION

The high recurrence rate of TT, 17 years after BTR surgery and high rates of TT in eyes that did not undergo surgical procedure earlier suggest that the causes of high recurrence should be identified and addressed. The ongoing pathologic condition of scarring of upper lids of both operated and unoperated eyes could be responsible for lid status after 17 years of BTR surgeries. High percentage of refusals because of long-term high recurrence could pose a challenge to reach the "elimination of blinding trachoma" by 2020.

The association between epilation and corneal opacity among eyes with trachomatous trichiasis

AIM

To examine the association between epilation and corneal opacity (CO) among trichiasis patients presenting for surgery.

METHODS

Cross sectional data from the STAR trial were utilised. Patients presenting for trichiasis surgery in Wolayta Zone, Ethiopia, were evaluated for current trichiasis status. Number of inturned lashes, evidence of epilation, level of entropion, trichiasis duration, and CO were collected. The primary outcome was prevalence of CO, stratified by entropion and epilation status.

RESULTS

Approximately 10% of eyes with mild entropion had CO, regardless of epilation status. Among eyes with moderate entropion, epilated eyes were less likely to have CO than non-epilated eyes (21% v 34% p = 0.002). The same association was seen in eyes with severe entropion: 43% of epilated eyes while 74% of non-epilated eyes had CO (p<0.0001). Presence of CO increased with age. Adjusted models showed a protective effect of epilation in eyes with moderate or severe entropion (OR: 0.51; 95% CI: 0.32 to 0.83 and OR: 0.24; 95% CI: 0.13 to 0.45, respectively). Among eyes with mild entropion there was no difference in the prevalence of CO comparing eyes that were epilated with those that were not epilated.

CONCLUSION

Entropion was the most significant predictor of CO. Cross sectional associations suggest that epilation may not be helpful for eyes with mild entropion, but may offer protection against CO in eyes with moderate to severe entropion. Epilation should not be a substitute for trichiasis surgery, however, as 43% of eyes with severe entropion that were epilated still had CO.

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

BACKGROUND/AIM

Trachomatous trichiasis frequently returns following surgery. Several factors may promote recurrence: preoperative disease severity, surgeon ability, surgical procedure, healing responses, and infection. This study investigates whether enhanced control of infection, both of Chlamydia trachomatis and other bacteria, with azithromycin can improve surgical outcome in a trachoma control programme.

METHODS

Individuals with trachomatous trichiasis were examined and operated. After surgery patients were randomised to the azithromycin or control group. The azithromycin group and children in their household were given a dose of azithromycin. Antibiotic treatment was repeated at 6 months. All patients were reassessed at 6 months and 12 months. Samples were collected for C trachomatis polymerase chain reaction and general microbiology at each examination.

RESULTS

451 patients were enrolled. 426 (94%) were reassessed at 1 year, of whom 176 (41.3%) had one or more lashes touching the eye and 84 (19.7%) had five or more lashes. There was no difference in trichiasis recurrence between the azithromycin and control group. Recurrent trichiasis was significantly associated with more severe preoperative trichiasis, bacterial infection, and severe conjunctival inflammation at 12 months. Significant variability in outcome was found between surgeons. Visual acuity and symptoms significantly improved following surgery.

CONCLUSION

In this setting, with a low prevalence of active trachoma, azithromycin did not improve the outcome of trichiasis surgery conducted by a trachoma control programme. Audit of trichiasis surgery should be routine.

Surgery for Trichiasis, Antibiotics to prevent Recurrence (STAR) Clinical Trial methodology

Trachoma is the leading infectious cause of blindness worldwide. Surgery is available to correct trichiasis, which results from repeated episodes of infection with C. trachomatis. However, trichiasis recurrence rates post-surgery are very high. Methods for reducing post-surgical trichiasis recurrence need to be explored. This paper outlines the design of the Surgery for Trichiasis, Antibiotics to prevent Recurrence (STAR) Clinical Trial currently underway in Ethiopia. The STAR trial, funded by The National Eye Institute, is a randomized, controlled clinical trial of antibiotic use at time of trichiasis surgery, comparing topical tetracycline to single-dose azithromycin for the surgical patient and single-dose azithromycin for the surgical patient and all household members. The primary outcome is trichiasis recurrence at one-year. Data from this trial will be critical in helping to determine future policy on antibiotic treatment for C. trachomatis following surgery.

Prevalence of cicatricial trachoma in an indigenous population of Central Australia: the Central Australian Trachomatous Trichiasis Study (CATTS)

BACKGROUND

Trachoma is one of the leading causes of blindness worldwide, resulting from conjunctival scarring, upper lid entropion and trichiasis, leading to corneal scarring and opacification. This study was designed to investigate the current prevalence of cicatricial trachoma in an indigenous population within Central Australia and help determine whether trachoma remains a public health issue.

METHODS

Participants aged 40 and over were recruited from patients attending one of 16 remote ophthalmology clinics held at indigenous communities in Central Australia within the Northern Territory. Once informed consent had been obtained, each patient underwent examination for evidence of trachomatous scarring, trachomatous trichiasis and corneal opacities. Results were collated and compared with previous prevalence surveys.

RESULTS

Among the sample (n = 181), there were 97 patients (54%; 95% CI 46.7-61.3) with trachomatous scarring, 15 patients (8%; 95% CI 2.8-13.2) with trichiasis and 5 patients (3%; 95% CI 0.5-5.5) with corneal opacities.

CONCLUSION

This study suggests that, although the prevalence of the cicatricial and blinding consequences of trachoma may be decreasing in patients aged 40 years or greater, when compared with the current prevalence in other areas of Australia, trachoma still remains a public health issue in Central Australia.

Long term outcome of trichiasis surgery in the Gambia

BACKGROUND

Trichiasis surgery is believed to reduce the risk of losing vision from trachoma. There are limited data on the long term outcome of surgery and its effect on vision and corneal opacification. Similarly, the determinants of failure are not well understood.

METHODS

A cohort of people in the Gambia who had undergone surgery for trachomatous trichiasis 3-4 years earlier was re-assessed. They were examined clinically and the conjunctiva was sampled for Chlamydia trachomatis polymerase chain reaction (PCR) and general bacterial culture.

RESULTS

In total, 141/162 people were re-examined. Recurrent trichiasis was found in 89/214 (41.6%) operated eyes and 52 (24.3%) eyes had five or more lashes touching the globe. Corneal opacification improved in 36 of 78 previously affected eyes. There was a general deterioration in visual acuity between surgery and follow up, which was greater if new corneal opacification developed or trichiasis returned. Recurrent trichiasis was associated with severe conjunctival inflammation and bacterial infection. C trachomatis was detected in only one individual.

CONCLUSIONS

Recurrent trichiasis following surgery is a common potentially sight threatening problem. Some improvement in the cornea can occur following surgery and the rate of visual loss tended to be less in those without recurrent trichiasis. The role of conjunctival inflammation and bacterial infection needs to be investigated further. Follow up of patients is advised to identify individuals needing additional surgical treatment.

One year recurrence of trachomatous trichiasis in routinely operated Cuenod Nataf procedure cases in Vietnam

BACKGROUND

Recurrence of trichiasis following surgery remains unacceptably high, regardless of the surgical procedure. Few prospective studies of sufficient size are available to assess the rate of recurrence and the factors contributing to recurrence. A prospective study of the modified Cuenod Nataf surgical procedure was conducted in Vietnam to determine recurrence and co-factors.

METHODS

The prospective study of Cuenod Nataf surgery for trachomatous trichiasis took place in four districts of Vietnam. All patients from identified villages who had surgery were followed for a period of 1 year. 10 Surgeons using standard techniques and recording procedures carried out the surgery. The presence of an eyelash touching the eyeball in the operated eye was considered as recurrence. Information on all subjects was recorded preoperatively, intraoperatively, and postoperatively. An independent examiner recorded postoperative information. Relative risks were calculated to assess the contribution of various risk factors to recurrence (by eye and by person). Cox proportional hazards modelling was used to assess the independent contribution of relevant factors to the outcome.

RESULTS

471 individuals had trichiasis surgery; 463 were followed for a period of 1 year. Overall, the recurrence rate was 10.8% (95% CI 8.0 to 13.6). Among people having surgery recurrence (one or both eyes) was most common in the most elderly (relative risk (RR) 2.49) and among those with a history of previous surgery (RR = 2.49). Cox proportional hazards analysis (by eye) revealed that visual acuity, conjunctival scarring, and suture adjustment were associated with recurrence at 1 year.

CONCLUSION

The Cuenod Nataf procedure, which is well accepted in the community and by eye care providers in Vietnam, has an acceptable 1 year success rate. Individuals with severe conjunctival scarring have the highest rate of recurrence suggesting that other surgical approaches are needed to manage these patients or that these patients need to be educated regarding the risk of recurrence. Active follow up of these patients would be warranted. The association with suture adjustment requires further investigation.

Low vision and blindness in adults in Gurage Zone, central Ethiopia

AIM

To determine the magnitude and causes of low vision and blindness in the Gurage zone, central Ethiopia.

METHODS

A cross sectional study using a multistage cluster sampling technique was used to identify the study subjects. Visual acuity was recorded for all adults 40 years and older. Subjects who had a visual acuity of <6/18 were examined by an ophthalmologist to determine the cause of low vision or blindness.

RESULTS

From the enumerated population, 2693 (90.8%) were examined. The prevalence of blindness (<3/60 better eye presenting vision) was 7.9% (95% CI 6.9 to 8.9) and of low vision (6/24-3/60 better eye presenting vision) was 12.1% (95% CI 10.9 to 13.3). Monocular blindness was recorded in 16.3% of the population. Blindness and low vision increased with age. The odds of low vision and blindness in women were 1.8 times that of the men. The leading causes of blindness were cataract (46.1%), trachoma (22.9%), and glaucoma (7.6%). While the prevalence of vision reducing cataract increased with age, the prevalence of trachoma related vision loss did not increase with age, suggesting that trichiasis related vision loss in this population might not be cumulative.

CONCLUSION

The magnitude of low vision and blindness is high in this zone and requires urgent intervention, particularly for women. Further investigation of the pattern of vision loss, particularly as a result of trachomatous trichiasis, is warranted.