[Etiology of corneal ulcers with special reference to bacterial genesis]

The authors report on 134 patients (141 eyes) seen between May 1982 and December 1985 with corneal ulcers with or without hypopyon. Eight patients (11 eyes) had a facial palsy, 7 (7 eyes) a varicella zoster infection, 1 (2 eyes) a marginal ulcer ("furrow keratitis") associated with collagenosis, 29 (29 eyes) an ulcerative keratitis with endophthalmitis, 1 (2 eyes) a pemphigoid-associated ulcer and 90 (92 eyes) a herpetic infection. Pathogenic bacterial strains were isolated from 20 patients: 10 coagulase-positive Staphylococcus aureus (4 coinfections), 3 Pseudomonas aeruginosa (1 coinfection), 2 Proteus mirabilis (1 coinfection), 2 Escherichia coli and Enterobacter cloacae, Citrobacter freundii and beta-hemolyzing streptococci as well as enterococci in one case each, and non-hemolyzing streptococci and alpha-hemolyzing streptococci in two cases each as coinfections. A comparison of the range of bacterial strains of postoperative endophthalmitis and kerato-/conjunctivitis with bacterial corneal ulcers revealed a high percentage of gram-negative organisms in the latter. Laboratory work-up should include microscopy, agar plating and differentiation as well as antibiotic sensitivity testing and modern immunofluorescent direct techniques. Management includes bactericidal topical and systemic antibiotic regimens as well as surgical procedures if necessary, e.g., perforating tectonic and mini-keratoplasty, and conjunctival flapping followed by lamellar keratoplasty.