Abstract
Purpose :
The aim of this audit is to assess the incidence of Acanthamoeba Keratitis (AK) in Northeast of England, with a focus on analysing associated risk factors and clinical outcomes, and comparing with our previous audit on AK, from 2004 to 2015.
Methods :
We conducted a retrospective review of consecutive cases diagnosed with AK, treated at Royal Victoria Infirmary, Newcastle upon Tyne, UK between Jan 2015 to Jun 2023. AK was confirmed either by positive corneal scrapes or contact lens (CL) culture. Patient demographics, diagnostic test (i.e., corneal scrape cultures, CL culture, in vivo confocal microscopy (IVCM)), treatment outcomes were obtained from medical records.
Results :
Twenty-two cases were identified, M:F 7:15, mean age at diagnosis 37.04 years (SD 12.63; range 17 - 64). Mean time to diagnosis from symptoms onset to starting treatment after securing diagnosis was 13.68 days (SD 9.74; range 5 – 44). Twenty-one cases were positive for AK on corneal scrapes culture and one was positive on CL culture. In 12% (n=3), AK was confirmed as bilateral. In 59% (n=13) IVCM was performed, 50% (n=11) showed double-walled cysts. 100% were CL users, of which 68% were using monthly disposable soft CLs.
Annual incidence of AK in our current audit was 0.86 case per million. Annual incidence from 2015 to 2018 was 1.08 per million (n=13), declined to 0.66 per million population (n=9) from Jan 2019 to Jun 2023.
Mean duration of treatment was 8.3 months (SD 3.1). All were treated with polyhexamethylene biguanide 0.02% to 0.06% and propamidine isethionate 0.1%. In 18% (n=4) it was changed to Chlorhexidine 0.02% and Hexamidine 0.1% respectively due to suboptimal response during treatment period. Three cases received topical steroid prior to AK diagnosis, of which two underwent penetrating keratoplasty.
Compared to our previous audit from 2015 (IOVS, June 2015, Vol.56, 1889) which had 14 AK cases over a period of 11.3 years, mean time to diagnosis reduced from 40 to 13.68 days. The mean duration of treatment increased from 7.5 to 8.3 months.
Conclusions :
We have observed a rise in AK over the years, when comparing this audit to our earlier one from 2015, during which the annual incidence was 0.42. Steroid use before AK diagnosis can worsen prognosis. Timely adjustments in therapy for cases that do not respond promptly may contribute to achieving a favourable visual outcome.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.