Hookworm Infestation as a Risk Factor for Mooren’s Ulcer in South India

Objective To investigate the association between Mooren's ulcer and intestinal hookworm infestation in South India. Design Prospective observational case–control study. Participants Fifteen patients with Mooren's ulcer and 30 age- and gender-matched controls seen at Aravind Eye Hospital. Methods Stool samples from the Mooren's ulcer patients and controls were collected and analyzed for presence of hookworm infestation. Main Outcome Measure Prevalence of hookworm infestation in Mooren's ulcer patients and controls. Results There was a statistically significant correlation between intestinal hookworm infestation and the occurrence of Mooren's ulcer ( P = 0.009). Retrospective exploratory subgroup analyses suggested that the correlation between intestinal hookworm infestation and the occurrence of Mooren's ulcer in men ( P P >0.99). Similarly, when both the Mooren's ulcer and the control subject groups were analyzed retrospectively by age > 50 years or age P = 0.017), whereas there was no statistically significant difference in the prevalence of hookworm infection between Mooren's ulcer subjects and control subjects ≤ 50 ( P = 0.31). Conclusion Intestinal hookworm infestation appears to be associated with the development of Mooren's ulcer in South India. Although the power of our retrospective exploratory subgroup analyses was limited by multiple testing and small sample sizes, these data suggest further that the correlation between intestinal hookworm infestation and the development of Mooren's ulcer may be greatest in male patients with more advanced age.