Lid flora in blepharitis.

The microbiologic evaluations of 332 consecutive patients with the primary diagnosis of chronic blepharitis were reviewed and compared to those of 160 control patients. The most commonly isolated organisms from lids with blepharitis were Staphylococcus epidermidis (95.8%), Propronibacterium acnes (92.8%), Corynebacterium sp. (76.8%), Acinetobacter sp. (11.4%), and Staphylococcus aureus (10.5%). Compared to controls, S. epidermidis (p less than 0.01), P. acnes (p less than 0.02), and Corynebacterium sp. (p less than 0.001) were present significantly more often. S. aureus and the isolation of more than one microbial species were not more common in blepharitis patients. Quantitatively, heavy growth, by total and individual species, was significantly more common in blepharitis patients (total, p less than 0.001; S. epidermidis, p less than 0.001, P. acnes, p less than 0.001). These data demonstrate that patients with blepharitis are more likely to have normal skin bacteria on their lids and in greater quantities than nonblepharitis patients.

Acridine orange and Gram stains in infectious keratitis.

Two hundred thirty consecutive cases of presumed infectious keratitis were reviewed. Cultures were positive in 49.5% (114 of 230). Acridine orange stain sensitivity (81%) was significantly greater than gram stain sensitivity (65%) (p less than 0.002). Gram stain specificity was 92%, and acridine orange specificity was 89%. In keratitis with low or moderate growth, acridine orange was positive in 73% (61 of 84) as compared with Gram stain 53% (45 of 84), (p less than 0.001). In cases of heavy microbial growth, Gram stain was positive in 97% (29 of 30), acridine orange in 100% (30 of 30). This study demonstrates that both Gram stain and acridine orange stain are excellent in cases of infectious keratitis with heavy microbial growth, but that acridine orange is significantly better than Gram stain in cases with low amounts of organisms.