Repository logo

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

Change log


Ngondi, Jeremiah 
Reacher, Mark 
Ole-Sempele, Francis 
Onsarigo, Alice 


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 > or = 6/18 in better eye); low vision (VA < 6/18 but > or = 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.



Adolescent, Adult, Age Distribution, Aged, Blindness, Child, Child, Preschool, Eyelid Diseases, Female, Hair Diseases, Humans, Male, Middle Aged, Prevalence, Severity of Illness Index, Sex Distribution, Sudan, Trachoma, Vision, Low

Journal Title

BMC Ophthalmol

Conference Name

Journal ISSN


Volume Title


Springer Science and Business Media LLC