April 2014
Volume 55, Issue 13
ARVO Annual Meeting Abstract  |   April 2014
Environmental Risk Factors for conjunctival scarring in a cohort of women in a trachoma hyperendemic area
Author Affiliations & Notes
  • Meraf Wolle
    Wimer Eye Institute, Baltimore, MD
  • Harran Mkocha
    Kongwa Trachoma Project, Kongwa, United Republic of Tanzania
  • Sheila K West
    Wimer Eye Institute, Baltimore, MD
  • Beatriz E Munoz
    Wimer Eye Institute, Baltimore, MD
  • Footnotes
    Commercial Relationships Meraf Wolle, None; Harran Mkocha, None; Sheila West, None; Beatriz Munoz, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science April 2014, Vol.55, 1670. doi:
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      Meraf Wolle, Harran Mkocha, Sheila K West, Beatriz E Munoz; Environmental Risk Factors for conjunctival scarring in a cohort of women in a trachoma hyperendemic area. Invest. Ophthalmol. Vis. Sci. 2014;55(13):1670.

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      © ARVO (1962-2015); The Authors (2016-present)

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Trachoma, an ocular infection caused by Chlamydia trachomatis, is the leading infectious cause of blindness worldwide. Approximately 150 million children have active trachoma, and about 1.3 million people, mainly adults, are blinded from the late sequelae, trichiasis (1). Survey data show that trachoma-related scarring, trichiasis and blindness are much more likely in women than in men. Understanding why women are more susceptible to progression toward the later stages of trachomatous disease is not well known (2). The goal of this study is to determine the environmental risk factors, apart from exposure to others with trachoma, that increase the risk for scarring trachoma in women. We hypothesize that exposure to indoor air pollution form cooking fires increases the risk of scarring and progression to severe scarring.


A study was conducted in 48 trachoma endemic villages in Kongwa Tanzania. Demographic information, ocular examinations for trachoma including ocular photographs of tarsal conjunctiva, and a variety of environmental exposure assessments were collected from a cohort of up to 4800 women aged 15 and older. Baseline characteristics of the first 652 members of the cohort were evaluated. Images of the upper eyelid were graded for the presence and severity of scarring, according to a four-step severity scale (3). A model was used to determine if the evaluated environmental exposures were associated with higher rates of conjunctival scarring.


Any scarring was present in 48% of these women, whose mean age was 35 years (Table 1). Moderate to severe scarring rates increased with age from 5% in those age 15-20, to 18% in those age 21 to 40, to 47% in those over age 40 (p<0.001) (Figure 1). Age adjusted rates of scarring were significantly higher in women who lived in houses with mud roofs, lived more than a 30 minute walk to water, or where the head of the household had less than 7 years of education. Age adjusted rates of scarring had a trend of being higher in houses with more indoor air pollution from cooking fires, where they cook in a room inside the house, where residents begin cooking at a younger age, and where no latrine was present. (Table 2)


Preliminary data suggest that the rate of scarring increases with age, and that those household characteristics associated with crowding and decreased hygiene also increased rates of scarring.

Keywords: 736 trachoma • 464 clinical (human) or epidemiologic studies: risk factor assessment  

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