Clinical and microbiological characteristics of fungal keratitis in the United States, 2001-2007: a multicenter study.

OBJECTIVE: To study the epidemiology, clinical observations, and microbiologic characteristics of fungal keratitis at tertiary eye care centers in the United States. DESIGN: Retrospective multicenter case series. PARTICIPANTS: Fungal keratitis cases presenting to participating tertiary eye care centers. METHODS: Charts were reviewed for all fungal keratitis cases confirmed by culture, histology, or confocal microscopy between January 1, 2001, and December 31, 2007, at 11 tertiary clinical sites in the United States. MAIN OUTCOME MEASURES: Frequency of potential predisposing factors and associations between these factors and fungal species. RESULTS: A total of 733 cases of fungal keratitis were identified. Most cases were confirmed by culture from corneal scraping (n = 693) or biopsies (n = 19); 16 cases were diagnosed by microscopic examination of corneal scraping alone; and 5 cases were diagnosed by confocal microscopy alone. Some 268 of 733 cases (37%) were associated with refractive contact lens wear, 180 of 733 cases (25%) were associated with ocular trauma, and 209 of 733 cases (29%) were associated with ocular surface disease. No predisposing factor was identified in 76 cases (10%). Filamentous fungi were identified in 141 of 180 ocular trauma cases (78%) and in 231 of 268 refractive contact lens-associated cases (86%). Yeast was the causative organism in 111 of 209 cases (53%) associated with ocular surface disease. Yeast accounted for few cases of fungal keratitis associated with refractive contact-lens wear (20 cases), therapeutic contact-lens wear (11 cases), or ocular trauma (21 cases). Surgical intervention was undertaken in 26% of cases and was most frequently performed for fungal keratitis associated with ocular surface disease (44%). Surgical intervention was more likely in cases associated with filamentous fungi (P = 0.03). Among contact lens wearers, delay in diagnosis of 2 or more weeks increased the likelihood of surgery (age-adjusted odds ratio = 2.2; 95% confidence interval, 1.2-4.2). CONCLUSIONS: Trauma, contact lens wear, and ocular surface disease predispose patients to developing fungal keratitis. Filamentous fungi are most frequently the causative organism for fungal keratitis associated with trauma or contact lens wear, whereas yeast is most frequently the causative organism in patients with ocular surface disease. Delay in diagnosis increases the likelihood of surgical intervention for contact lens-associated fungal keratitis.

Comparison of photorefractive keratectomy and laser in situ keratomileusis for the treatment of compound hyperopic astigmatism.

PURPOSE: To compare photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for compound hyperopic astigmatism. SETTING: University laser center. METHODS: This prospective nonrandomized study evaluated 41 consecutive eyes (27 patients) that had PRK and 24 consecutive eyes (15 patients) that had LASIK to correct compound hyperopic astigmatism. RESULTS: The mean preoperative error was +3.06 diopters of sphere (DS) +/-1.73 (SD)/+1.31 +/- 0.60 diopters of cylinder (DC) in the PRK eyes and +2.86 +/-1.28 DS/+1.55 +/- 0.96 DC in the LASIK eyes. The mean maximal pain score in PRK eyes was 1.95 +/- 1.19 (range 0.0 to 3.0) in PRK eyes and 0.84 +/-1.12 in LASIK eyes (P=.0014). The uncorrected visual acuity was 20/20 or better in 7.7% of the PRK eyes and 58.3% of the LASIK eyes at 1 month (P<.001) and 57.9% and 66.7%, respectively, at 9 months (P=.586). The mean postoperative spherical error was -0.95 +/- 0.92 D in PRK eyes and +0.33 +/- 0.56 D in LASIK eyes at 1 month (P<.001) and +0.64 +/- 1.01 D and +0.44 +/- 0.57 D, respectively, at 9 months (P=.375). There was no statistically significant between-group difference in the mean residual astigmatic error. Mild peripheral haze (grade 0.5 to 1.0) occurred in 19.5% of PRK eyes and no LASIK eye. No eye in either group lost more than 2 lines of best spectacle-corrected visual acuity. CONCLUSIONS: Photorefractive keratectomy was more painful than LASIK and led to a slower visual recovery, a higher incidence of peripheral haze, and an initial myopic overcorrection, which self-corrected by 3 to 6 months. Efficacy and stability of the astigmatic correction were similar in both groups. Long-term stability of both procedures requires further study.

The role of inflammation and antiinflammation therapies in keratoconjunctivitis sicca.

PURPOSE: To review and integrate recent advances in identifying the role of inflammation in the pathogenesis of dry eye conditions and the biological rationale and practical clinical aspects of newer, antiinflammatory theories. METHODS: A comprehensive literature survey. RESULTS AND CONCLUSION: Keratoconjunctivitis Sicca (KCS) is a multifactorial and complex disorder in which ocular surface inflammations play a central role. Identification of specific CD4-T-Cell pathways and the recent recognition of targeting of alpha-fodrin suggest a case for novel new therapeutic aspects such as anti-CD4 monoclonal antibodies, systemic linoleic and gamma-linolenic acids, and omega-6 essential fatty acids. Replacement of tear volume with nonpreserved wetting agents and standard typical antiinflammatory corticosteroid and/or cyclosporine A continues to be central current conventional therapy for KCS.

Corneal oxygen deficiency.

OBJECTIVES: To compare the ocular effects of low Dk hydrogel and high Dk silicone hydrogel contact lenses. METHODS: A review of recent literature was conducted to determine the effects of wearing low and high Dk soft lenses on corneal swelling, vascular response, refractive error and the corneal epithelium. RESULTS: High Dk silicone hydrogel contact lenses became available for research and clinical practice almost 10 and 5 years ago respectively. During that time many studies have been conducted and it has been demonstrated repeatedly how much improvement there has been to the physiological response of the eye particularly when wearing the lenses on an overnight basis. CONCLUSIONS: Although silicone hydrogels only constitute about 2% of current wearers, their positive effects on the eye compared with low Dk hydrogel lenses should make them the most dominant lenses in the near future.