Purpose: To evaluate the specific risk factors responsible for the development of pneumococcal keratitis.
Methods: In a retrospective analysis of 383 patients of culture-proven bacterial keratitis, seen between 1991 and 1995, 139 had monobacterial isolates on culture. We analyzed the various predisposing factors in these patients, with special emphasis on the patency of nasolacrimal drainage system.
Results: Of the 139 patients with monobacterial keratitis, 48 (group 1) grew Streptococcus pneumoniae in culture. In the remaining 91 patients (group 2), Pseudomonas (18), coagulase-negative Staphylococci (15), Staphylococcus epidermidis (23), Staphylococcus aureus (16), Corynebacterium species (12), and others (seven) were isolated. Trauma was found to be a predisposing factor in 12 patients of group 1 and 27 patients of group 2 (p = 0.5601). Twelve (25%) patients of group 1 revealed chronic dacryocystitis, and nine of them underwent sac excision. On the contrary, only three patients of group 2 demonstrated dacryocystitis (p = 0.0003).
Conclusion: These results underscore the importance of assessing the patency of lacrimal drainage system in patients with infectious keratitis, especially of pneumococcal origin.