Microbial keratitis at extremes of age

Purpose: To study the risk factors, clinical presentation, response to treatment and outcome of microbial keratitis occurring in patients at extremes of age (ie, children and the elderly) and to compare them with microbial keratitis affecting the general adult population. Methods: In this prospective, nonrandomized, analytical clinical study, all patients presenting with microbial keratitis and undergoing microbiological workup over a 1-year period were evaluated using a dedicated corneal ulcer protocol. Patients were divided into 3 groups based on age: (1) pediatric group if the age was 16 years or younger, (2) elderly group if the age was 65 years or older, and (3) control group if the age was between 17 and 64 years. Features studied included microbiological profile, predisposing factors, clinical presentation, response to treatment, and final visual outcome. Results: A total of 269 eyes of 269 patients were studied (26 in the pediatric group, 55 in the elderly group, and 188 in the control group). Culture positivity rates were similar in all the groups. The elderly and control groups had a similar incidence of fungal and bacterial keratitis, but the pediatric group had a significantly lower incidence of fungal keratitis (P = 0.001). Trauma was the most common predisposing factor in all groups. Elderly patients tended to present with a higher incidence of central ulcers (P = 0.04), severe ulcers (P = 0.04), and poor visual acuity (P = 0.003) as compared with the control group. The percentage of ulcers healing with medical treatment alone was significantly more in the pediatric group (P = 0.004), while the incidence of poor visual outcome was greater in the elderly group (P = 0.006) as compared with the control group. Conclusions: Microbial keratitis in pediatric patients is more likely to be of bacterial etiology, and nonsevere ulcers in this age group have a better chance of resolution with medical therapy alone when compared with that in the general adult population. Conversely, elderly patients with microbial keratitis tend to present with severe, central ulcers with a significant risk of having a poor visual outcome.