Visual outcome in Japanese patients with Acanthamoeba keratitis

Abstract

Purpose To identify prognostic factors affecting visual outcome in Acanthamoeba keratitis (AK) treated with topical chlorhexidine gluconate (CHG). Methods A total of 35 eyes in 34 patients with AK were treated with 0.02% topical CHG. Patients were divided into two groups according to the final visual outcome: Group 1, final visual acuity (VA) of 20/25 or greater (22 eyes); Group 2, less than 20/25 (13 eyes). We compared these groups and evaluated the effectiveness of topical CHG compared with outcomes in previous reports. Results Ring infiltrate was observed more often in Group 2 (4.5% vs 61.5%, OR 33.6, 95% confidence interval (CI) 3.4-333.9, Po0.01). The duration between onset and diagnosis of AK was significantly longer (24.9 days vs 48.4 days, OR 1.03, 95% CI 1.00-1.06, P ¼ 0.04) and VA at initial examination (log MAR) significantly lower (0.47 vs 1.59, OR 25.5, 95% CI 3.4-186.7, Po0.01) in Group 2 (visual outcome o20/25). Multivariate analysis revealed that only VA at initial examination was independently associated with worse visual outcome (adjusted OR 24.5, 95% CI 1.9-312.6, P ¼ 0.01). Seventeen (85.0%) of the 20 eyes diagnosed within 1 month and 24 (82.8%) of 29 eyes diagnosed within 2 months achieved a VA of 20/40 or greater. Conclusion VA at initial examination was the most predictive factors for final visual outcome in AK. Topical CHG was comparably effective to other treatments, including polyhexamethyl biguanide and propamidine isethionate.

Risk factors, demographics and clinical profile of Acanthamoeba keratitis in Melbourne: an 18-year retrospective study

“…However, five cases (14.7%) were identified in our series as DDCL users. This is similar Yamazoe  et al ’s study14 where seven out of 34 cases (20.5%) were DDCL users. We agree with his statement that it is difficult to generalise the level of risk of AK in DDCL users as CL care and practices differ greatly among individuals.…”

“…The low average incidence of 2 per year in our study is similar to studies where an outbreak has not been reported, both in Australia11 12 and in other countries such as New Zealand,7 Hong Kong,9 Japan14 and USA (Cleveland4 and Philadelphia3), where the number of cases has ranged from 1.5 per year to 3.6 cases per year. Melbourne’s clean water could account for the low incidence of AK; Melbourne has some of the highest quality drinking water in the world where great care is taken to disinfect water sources via chlorination, chloramination and ultraviolet irradiation 15.…”

Strategies for the prevention of contact lens‐related Acanthamoeba keratitis: a review

“…In some centres, epithelial debridement is performed at diagnosis . This is thought to remove some of the organism load and aid penetration of the anti‐amoebic drugs to deeper layers of the cornea.…”

“…58 In some centres, epithelial debridement is performed at diagnosis. 59 This is thought to remove some of the organism load and aid penetration of the anti-amoebic drugs to deeper layers of the cornea. It appeared effective in small case series, 59 however to fully assess this practice, a randomised controlled trial would be needed.…”

Ocular parasitosis caused by protozoan infection during travel: Focus on prevention and treatment

“…Other documented causes include swimming and showering with contact lenses in situ , exposure to contaminated water or soil, and corneal trauma. Some studies showed that AK was more prevalent during warmer seasons, especially during the summer,[ 63 64 65 66 ] but others revealed no significant seasonal differences. [ 67 ] This difference is perhaps due to more swimming and showering in summer.…”