PURPOSE: In recent years, outbreaks of Acanthamoeba keratitis (AK) have been reported worldwide. The purpose of this study was to examine the clinical experience of AK at the Massachusetts Eye and Ear Infirmary. METHODS: A retrospective case review was completed on patients with infectious keratitis whose corneal cultures were positive for Acanthamoeba between January 2000 and December 2008. The clinical characteristics and visual outcomes were examined in those patients with a follow-up period greater than 6 months. RESULTS: Four cases were identified between January 2000 and December 2003, whereas 26 cases were identified between January 2004 and December 2008. Charts before 2004 were unavailable for review. A total of 15 cases between 2004 and 2008 had a follow-up period of greater than 6 months. In these cases, possible risk factors associated with AK included soft contact lens wear (12 of 15 cases), exposure to freshwater or saltwater sources (8 of 15 cases), chronic ocular surface disease (6 of 15 cases), ocular trauma (3 of 15 cases), and concomitant infectious keratitis (2 of 15 cases). Four cases were associated with the use of Advanced Medical Optics Complete MoisturePlus Multi-Purpose Solution. Many cases were recalcitrant to medical therapy alone, necessitating therapeutic penetrating keratoplasty in 8 of 15 cases. CONCLUSIONS: The number of AK cases at the Massachusetts Eye and Ear Infirmary has increased since 2004. Contact lens wear and exposure to contaminated water sources were potential risk factors for AK. Clinicians should maintain a high clinical suspicion for AK in cases of atypical keratitis with known risk factors for AK.
PURPOSE: In recent years, outbreaks of Acanthamoeba keratitis (AK) have been reported worldwide. The purpose of this study was to examine the clinical experience of AK at the Massachusetts Eye and Ear Infirmary. METHODS: A retrospective case review was completed on patients with infectious keratitis whose corneal cultures were positive for Acanthamoeba between January 2000 and December 2008. The clinical characteristics and visual outcomes were examined in those patients with a follow-up period greater than 6 months. RESULTS: Four cases were identified between January 2000 and December 2003, whereas 26 cases were identified between January 2004 and December 2008. Charts before 2004 were unavailable for review. A total of 15 cases between 2004 and 2008 had a follow-up period of greater than 6 months. In these cases, possible risk factors associated with AK included soft contact lens wear (12 of 15 cases), exposure to freshwater or saltwater sources (8 of 15 cases), chronic ocular surface disease (6 of 15 cases), ocular trauma (3 of 15 cases), and concomitant infectious keratitis (2 of 15 cases). Four cases were associated with the use of Advanced Medical Optics Complete MoisturePlus Multi-Purpose Solution. Many cases were recalcitrant to medical therapy alone, necessitating therapeutic penetrating keratoplasty in 8 of 15 cases. CONCLUSIONS: The number of AK cases at the Massachusetts Eye and Ear Infirmary has increased since 2004. Contact lens wear and exposure to contaminated water sources were potential risk factors for AK. Clinicians should maintain a high clinical suspicion for AK in cases of atypical keratitis with known risk factors for AK.