Objective: To determine the prevalence of keratoconus among patients with allergic conjunctivitis aged
between 8 and 30 years, attending Kenyatta National Hospital eye clinic.
Methods: A cross sectional study of patients on follow up for allergic conjunctivitis. They were examined on the
slit lamp, clinical signs of keratoconus were elicited, and then keratometry and corneal topography was done on
each of them. The social demographic and clinical data was captured in a questionnaire. Descriptive analysis of
the data was done to determine means, frequencies and proportions of the various variables. The relationship
between the demographic characteristics of the patients, the duration and severity of allergic conjunctivitis,
with keratoconus was assessed.
Results: Two hundred and forty six eyes of 123 patients were examined. Keratoconus prevalence was found to
be 10.6% by clinical diagnosis, 14.6% by keratometry and 30.9% by topography. Majority of those diagnosed
with keratoconus were aged 10 to 14 years (42.1%). The male: female ratio of those with keratoconus was 1.9:1,
and among them 34.2% had moderate allergic conjunctivitis, and 42.1% had severe allergic conjunctivitis, which
was statistically significant. Patients with allergy symptoms for more than 10 years formed the largest proportion
of those with keratoconus (42.1%).
Conclusion: The prevalence of keratoconus in patients with allergic conjunctivitis was found to be high and
the majority were male. Corneal topography diagnosed more patients with keratoconus, and therefore is highly
recommended as part of the follow up investigations for all patients with allergic conjunctivitis. This will ensure
early detection and management of the condition.
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