title: Use of lactophenol cotton blue mounts of corneal scrapings as an aid to the diagnosis of mycotic keratitis.
abstract: Lactophenol cotton blue (LPCB) mounts of corneal ulcer scrapings were assessed as a diagnostic tool in cases of mycotic keratitis over a period of 15 months. We investigated 568 cases of ulcerative keratitis by microbiological techniques consisting of direct microscopic examination of LPCB mounts and Gram-stained smears as well as culture of material scraped from the ulcer. Fungi were isolated in large numbers on multiple media from the corneal scrapings of 179 patients (culture-proven mycotic keratitis). Direct microscopic examination of LPCB mounts of corneal scrapings yielded positive results in 140 (78%) of 179 culture-positive patients and negative results in 371 (95%) of 389 culture-negative patients. There was a significant difference between the percentage of positive results obtained by LPCB mounts and by Gram-stained smears in the culture-positive cases. The LPCB mount was positive in greater than 80% of cases of keratitis due to Fusarium spp. and Aspergillus spp. The LPCB mount is strongly recommended as a simple, rapid, inexpensive, and sensitive diagnostic technique in cases of mycotic keratitis.
authors.affiliation: Department of Microbiology, Joseph Eye Hospital, Tiruchirapalli, India.
authors.forename: P A
authors.initials: PA
authors.lastname: Thomas
authors.forename: T
authors.initials: T
authors.lastname: Kuriakose
authors.forename: M P
authors.initials: MP
authors.lastname: Kirupashanker
authors.forename: V S
authors.initials: VS
authors.lastname: Maharajan
mesh_terms: D001230:Aspergillus / Q000302:isolation & purification; D001557:Benzenesulfonates; D003315:Cornea / Q000382:microbiology*; D003320:Corneal Ulcer / Q000175:diagnosis* / Q000382:microbiology; D015821:Eye Infections, Fungal / Q000175:diagnosis* / Q000382:microbiology; D005658:Fungi / Q000302:isolation & purification*; D005670:Fusarium / Q000302:isolation & purification; D005840:Gentian Violet; D006801:Humans; D007773:Lactates; D019344:Lactic Acid; D010619:Phenazines; D010636:Phenols; D013194:Staining and Labeling
chemical_list: D001557:Benzenesulfonates; C035863:Gram's stain; D007773:Lactates; D010619:Phenazines; D010636:Phenols; D019344:Lactic Acid; C062934:lactophenol cotton blue; D005840:Gentian Violet