Eyelash Epilation in the Absence of Trichiasis: Results of a Population-Based Prevalence Survey in the Western Division of Fiji

The prevention and management of postoperative trachomatous trichiasis: A systematic review

Among ocular infections, trachoma is the main cause of blindness. Repeated conjunctival Chlamydia trachomatis infections lead to trichiasis, corneal opacification, and visual impairment. Surgery is often needed to relieve discomfort and preserve vision; however, a high postoperative trachomatous trichiasis (PTT) rate has been observed in various settings. We wanted to know why, whether PTT rates could be reduced, and how to manage the PTT that occurs. We performed a search of the literature. Of 217 papers screened, 59 studies were identified for inclusion as potentially relevant, the majority having been excluded for not directly concerning PTT in humans. Preventing PTT is a major challenge. Only one published trial, the STAR trial in Ethiopia, has reported a cumulative PTT rate <10% one year after surgery. The literature on the management of PTT is sparse. Though no PTT management guidelines are available, high-quality surgery with a low rate of unfavorable outcomes for PTT patients is likely to require enhanced training of a smaller group of highly-skilled surgeons. Based on the surgical complexity and the authors' own experience, the pathway for patients suffering from PTT should be studied further for improvement.

Trachoma

Trachoma is a neglected tropical disease caused by infection with conjunctival strains of Chlamydia trachomatis. It can result in blindness. Pathophysiologically, trachoma is a disease complex composed of two linked chronic processes: a recurrent, generally subclinical infectious-inflammatory disease that mostly affects children, and a non-communicable, cicatricial and, owing to trichiasis, eventually blinding disease that supervenes in some individuals later in life. At least 150 infection episodes over an individual's lifetime are needed to precipitate trichiasis; thus, opportunity exists for a just global health system to intervene to prevent trachomatous blindness. Trachoma is found at highest prevalence in the poorest communities of low-income countries, particularly in sub-Saharan Africa; in June 2021, 1.8 million people worldwide were going blind from the disease. Blindness attributable to trachoma can appear in communities many years after conjunctival C. trachomatis transmission has waned or ceased; therefore, the two linked disease processes require distinct clinical and public health responses. Surgery is offered to individuals with trichiasis and antibiotic mass drug administration and interventions to stimulate facial cleanliness and environmental improvement are designed to reduce infection prevalence and transmission. Together, these interventions comprise the SAFE strategy, which is achieving considerable success. Although much work remains, a continuing public health problem from trachoma in the year 2030 will be difficult for the world to excuse.

Trachoma, Anti-Pgp3 Serology, and Ocular Chlamydia trachomatis Infection in Papua New Guinea

BACKGROUND

In Melanesia, the prevalence of trachomatous inflammation-follicular (TF) suggests that public health-level interventions against active trachoma are needed. However, the prevalence of trachomatous trichiasis is below the threshold for elimination as a public health problem and evidence of conjunctival infection with trachoma's causative organism (Chlamydia trachomatis [CT]) is rare. Here, we examine the prevalence of ocular infection with CT and previous exposure to CT in three evaluation units (EUs) of Papua New Guinea.

METHODS

All individuals aged 1-9 years who were examined for clinical signs of trachoma in 3 Global Trachoma Mapping Project EUs were eligible to take part in this study (N = 3181). Conjunctival swabs were collected from 349 children with TF and tested by polymerase chain reaction to assess for ocular CT infection. Dried blood spots were collected from 2572 children and tested for anti-Pgp3 antibodies using a multiplex assay.

RESULTS

The proportion of children with TF who had CT infection was low across all 3 EUs (overall 2%). Anti-Pgp3 seroprevalence was 5.2% overall and there was no association between anti-Pgp3 antibody level and presence of TF. In 2 EUs, age-specific seroprevalence did not increase significantly with increasing age in the 1- to 9-year-old population. In the third EU, there was a statistically significant change with age but the overall seroprevalence and peak age-specific seroprevalence was very low.

CONCLUSIONS

Based on these results, together with similar findings from the Solomon Islands and Vanuatu, the use of TF to guide antibiotic mass drug administration decisions in Melanesia should be reviewed.

The simplified trachoma grading system, amended

A simplified grading system for trachoma was published by the World Health Organization (WHO) in 1987. Intended for use by non-specialist personnel working at community level, the system includes five signs, each of which can be present or absent in any eye: (i) trachomatous trichiasis; (ii) corneal opacity; (iii) trachomatous inflammation—follicular; (iv) trachomatous inflammation—intense; and (v) trachomatous scarring. Though neither perfectly sensitive nor perfectly specific for trachoma, these signs have been essential tools for identifying populations that need interventions to eliminate trachoma as a public health problem. In 2018, at WHO’s 4th global scientific meeting on trachoma, the definition of one of the signs, trachomatous trichiasis, was amended to exclude trichiasis that affects only the lower eyelid. This paper presents the amended system, updates its presentation, offers notes on its use and identifies areas of ongoing debate.

The global burden of trichiasis in 2016

Background

Trichiasis is present when one or more eyelashes touches the eye. Uncorrected, it can cause blindness. Accurate estimates of numbers affected, and their geographical distribution, help guide resource allocation.

Methods

We obtained district-level trichiasis prevalence estimates in adults for 44 endemic and previously-endemic countries. We used (1) the most recent data for a district, if more than one estimate was available; (2) age- and sex-standardized corrections of historic estimates, where raw data were available; (3) historic estimates adjusted using a mean adjustment factor for districts where raw data were unavailable; and (4) expert assessment of available data for districts for which no prevalence estimates were available.

Findings

Internally age- and sex-standardized data represented 1,355 districts and contributed 662 thousand cases (95% confidence interval [CI] 324 thousand–1.1 million) to the global total. Age- and sex-standardized district-level prevalence estimates differed from raw estimates by a mean factor of 0.45 (range 0.03–2.28). Previously non- stratified estimates for 398 districts, adjusted by ×0.45, contributed a further 411 thousand cases (95% CI 283–557 thousand). Eight countries retained previous estimates, contributing 848 thousand cases (95% CI 225 thousand-1.7 million). New expert assessments in 14 countries contributed 862 thousand cases (95% CI 228 thousand–1.7 million). The global trichiasis burden in 2016 was 2.8 million cases (95% CI 1.1–5.2 million).

Interpretation

The 2016 estimate is lower than previous estimates, probably due to more and better data; scale-up of trichiasis management services; and reductions in incidence due to lower active trachoma prevalence.

As an individual with trichiasis blinks, the eyelashes abrade the cornea, which can lead to corneal opacity and blindness. Through high quality surgery, which involves altering the position of the eyelid margin, it is possible to reduce the number of people with trichiasis. Accurate estimates of the number of persons with trichiasis and their geographical distribution are needed in order to effectively align resources for surgery and other necessary services. We obtained district-level trichiasis prevalence estimates for 44 endemic and previously-endemic countries. We used the most recently available data and expert assessments to estimate the global burden of trichiasis. We estimated that in 2016 the global burden was 2.8 million cases (95% CI 1.1–5.2 million).

The 2016 estimate is lower than previous estimates, probably due to more and better data; scale-up of trichiasis management services; and reductions in incidence due to lower active trachoma prevalence.

A search for trachoma in Timor-Leste: no evidence to justify undertaking population-based prevalence surveys

Purpose

We sought evidence to justify undertaking population-based trachoma surveys in Timor-Leste, believing that in the absence of such evidence, the country could be categorized as not needing interventions to eliminate trachoma.

Methods

We undertook a systematic review of published literature on trachoma in Timor-Leste, with results updated to 28 April 2018. We also undertook a series of clinic- and field-based screening exercises, consisting of: (1) in October 2015, conjunctival examination of all children attending a school in Vila, Atauro Island; (2) from 1 November 2016 to 30 April 2017, examination for trichiasis, by specifically-trained frontline eye workers, of all individuals presenting to the ophthalmic clinics of six referral hospitals and five district eye clinics; and (3) house-to-house case searches in a total of 110 households, drawn from three communities that were reported by investigators from the 2016 Rapid Assessment of Avoidable Blindness (RAAB) to include residents with trachoma.

Results

Three RAABs (2005, 2009–2010, 2016) and two relevant published papers were identified. The 2016 RAAB reported one female subject to have been diagnosed with trachomatous corneal opacity. Re-examination of that individual revealed that she had ankyloblepharon, without evidence of trichiasis or entropion. No children on Atauro Island, no clinic attendees, and no individuals examined in the targeted house-to-house searches had any sign of trachoma.

Conclusion

Trachoma is very unlikely to be a public health problem in Timor-Leste. It would not be appropriate to incur the costs of conducting formal population-based trachoma prevalence surveys here.

A systematic review of historical and contemporary evidence of trachoma endemicity in the Pacific Islands

INTRODUCTION

Trachoma is endemic in several Pacific Island countries. The aims of this study were to (a) identify future trachoma mapping needs in the Pacific and (b) to examine whether any temporal trends in trachoma prevalence could be ascertained from the historical literature on trachoma in the Pacific Islands.

METHODS

Human studies of trachoma and eye care in the Pacific Islands were identified from a systematic search of PubMed, EMbase, Scopus and Web of Science databases. A published quality assessment system for disease prevalence studies was modified to assess studies for quality and transparency.

RESULTS

Few general ophthalmic studies in the Pacific mention trachoma. In targeted studies of trachoma, cases have consistently been identified throughout the Pacific since the early twentieth century. The largest number of studies come from Papua New Guinea and Fiji, whereas some countries have no published data on trachoma. The majority of studies identified were published before the Alliance for the Global Elimination of Trachoma 2020 was convened, so lack the standardisation of population-based mapping which has been implemented in the past decade.

CONCLUSIONS

Population-based trachoma prevalence estimates have been recently generated in Papua New Guinea, Solomon Islands, Vanuatu, Kiribati and Fiji. There is insufficient evidence to assess whether there has been temporal change in trachoma prevalence in these countries over the past century. Cases of trachoma have been identified in some countries (for example, Nauru and Samoa) which have no recent population-based mapping data, but may be at risk of trachoma endemcitiy. Deployment of appropriate mapping strategies is warranted to identify whether interventions are required.

Serology reflects a decline in the prevalence of trachoma in two regions of The Gambia

Trachoma is caused by Chlamydia trachomatis (Ct). It is targeted for global elimination as a public health problem. In 2014, a population-based cross-sectional study was performed in two previously trachoma-endemic areas of The Gambia. Participants of all ages from Lower River Region (LRR) (N = 1028) and Upper River Region (URR) (N = 840) underwent examination for trachoma and had blood collected for detection of antibodies against the Ct antigen Pgp3, by ELISA. Overall, 30 (1.6%) individuals had active trachoma; the prevalence in children aged 1-9 years was 3.4% (25/742) with no statistically significant difference in prevalence between the regions. There was a significant difference in overall seroprevalence by region: 26.2% in LRR and 17.1% in URR (p < 0.0001). In children 1-9 years old, seroprevalence was 4.4% in LRR and 3.9% in URR. Reversible catalytic models using information on age-specific seroprevalence demonstrated a decrease in the transmission of Ct infection in both regions, possibly reflecting the impact of improved access to water, health and sanitation as well as mass drug administration campaigns. Serological testing for antibodies to Ct antigens is potentially useful for trachoma programmes, but consideration should be given to the co-endemicity of sexually transmitted Ct infections.