Abstract
Purpose To report on glaucoma-related ocular parameters, namely intraocular pressure and peripheral anterior synechiae, in the presence of onchocercal infection.
Methods Two computer-generated random samples of individuals were drawn from communities mesoendemic and nonendemic for onchocerciasis respectively. Applanation tonometry and gonioscopy were carried out on these individuals.
Results Four hundred and thirty-six and 319 individuals from the mesoendemic and nonendemic communities were examined respectively. The mean intraocular pressure was 1.58 mmHg lower in the individuals from the mesoendemic communities compared with those from the nonendemic communities (p < 0.001) despite the prevalence of peripheral anterior synechiae being higher in the mesoendemic communities. In these communities, there was strong evidence that the prevalence of peripheral anterior synechiae increased with increasing microfilarial load.
Conclusions Onchocercal infection produces a low-grade inflammatory process, which may result in a lowering of intraocular pressure despite the formation of peripheral anterior synechiae. Glaucomatous optic nerve damage therefore not be the primary cause of visual loss in ocular onchocerciasis as this occurs late and is probably preceded by other blinding onchocercal pathology.
Similar content being viewed by others
Article PDF
References
WHO expert committee on onchocerciasis control. Onchocercisasis and its control. WHO Technical report series 852. Geneva: WHO, 1995:1–104.
Whitworth JA, Gilbert CE, Mabey DM, Morgan D, Foster A . Visual loss in an onchocerciasis endemic community in Sierra Leone. Br J Ophthalmol 1993;77:30–2.
Abiose A, Murdoch I, Babalola O, Cousens S, Liman I, Onyema J, et al. Distribution and aetiology of blindness and visual impairment in mesoendemic onchocercal communities, Kaduna State, Northern Nigeria. Br J Ophthalmol 1994;78:8–13.
Moll AC, Van der Linden AJ, Hogweg M, Schader WE, Hermans J, De Keizer RJ . Prevalence of blindness and low vision of people over 30 years in the Wenchi district Ghana, in relation to eye care programmes. Br J Ophthalmol 1994;78:275–9.
Schwartz EC, Huss R, Hopkins A, Dadjim B, Madjitoloum P, Henault C, et al. Blindness and visual impairment in a region endemic for onchocerciasis in the Central African Republic. Br J Ophthalmol 1997;81:443–7.
Adeoye A . Survey of blindness in rural communities of South-Western Nigeria. Trop Med Int Health 1996;1:672–6.
Hissette J . Ocular onchoceriasis. Am J Trop Med 1938;18(Suppl):58–90.
Quevedo A . Ocular onchocerciasis. Am J Ophthalmol 1941;24:1185–9.
Sarkies JWR . Ocular onchocerciasis. Br J Ophthalmol 1952;32:81–99.
Quarcoopome CO . Onchocerciasis. Ghana Med J 1970;9:234.
Berghout E . Onchocerciasis and glaucoma in the forest area of Ghana. Trop Geogr Med 1973;25:233–7.
Langham ME, Frentzel-Beyme RR, Traub ZD . Intraocular pressure and onchocerciasis infection in Liberia. Ophthalmic Res 1975;7:368–80.
Dallo JS . Onchcercose: manifestations ophthalmologiques des parasitoses. Soc Fr Ophtalmol 1985. Paris: Masson.
Anderson J, Fuglsang H, de C Marshall TF . Effects of suramin on ocular onchocerciasis. Tropenmed Parasitol 1976;27:279–96.
Thylefors B . Intraocular pressure in onchocerciasis: some preliminary results of a field evaluation. Bull WHO J 1976;54:113–4.
Thylefors B, Duppenthaler JL . Epidemiological aspects of intraocular pressure in an onchocerciasis endemic area. Bull WHO 1979;57:963–9.
Abiose A, Jones BR, Cousens SN, Murdoch I, Cassels-Brown A, Babalola OE, et al. Reduction in incidence of optic nerve disease with annual ivermectin to control onchocerciasis. Lancet 1993;341:130–4.
Cousens SN, Yahaya H, Murdoch I, Samaila E, Evans J, Babalola OE, et al. Risk factors for optic nerve disease in communities mesoendemic for savannah onchocerciasis, Kaduna State, Nigeria. Trop Med Int Health 1997;2:89–98.
Buck AA, editor. Onchocerciasis: symptomatology, pathology, diagnosis. Geneva: WHO, 1974.
Wormald R, Foster A . Clinical and pathological features of chronic glaucoma in north-east Ghana. Eye 1990;4:107–14.
Verrey JD, Foster A, Wormald R, Akuamoa C . Chronic glaucoma in Northern Ghana: a retrospective study of 397 patients. Eye 1990;4:115–20.
Author information
Authors and Affiliations
Corresponding author
Additional information
Proprietary interest: None
Research funding: WHO project no. 870456, The Leverhulme Trust, Sight Savers
Rights and permissions
About this article
Cite this article
Yang, Y., Cousens, S., Murdoch, I. et al. Intraocular pressure and gonioscopic findings in rural communities mesoendemic and nonendemic for onchoceriasis, Kaduna State, Nigeria. Eye 15, 756–759 (2001). https://doi.org/10.1038/eye.2001.244
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/eye.2001.244