Re-emerging Acanthamoeba Keratitis (AK): Shift in diagnostic trends and outcomes Glasgow Experience U Agraval, K Ramaesh, D Anijeet Tennent institute of ophthalmology, Glasgow  The authors have no financial interest to disclose

Purpose Acanthamoeba keratitis (AK) appears to be re-emerging and remains a diagnostic challenge INCIDENCE 1973: First Case of Acanthamoeba Keratitis 1989: US 1.36 per million contact len (CL) wearers 1999: Netherlands 3.06 per million CL wearers 1999: West of Scotland 149 per million CL wearers 2002: England/Wales 21 per million CL wearers Diagnostic methods such as polymerase chain reaction (PCR) have made early diagnosis possible in high risk patients We report the diagnosis, management and outcomes of patient with AK

methods Retrospective study of 22 patients diagnosed with contact lens related AK at Gartnavel General Hospital, Glasgow Between January 2009 to July 2014 DATA COLLECTION Demographics Delay in AK diagnosis Type of contact lens Diagnosis method Signs and symptoms on presentation Treatment Visual outcome Clinical features: early or late Additional procedures Initial visual acuity Recurrence rate Initial diagnosis Follow up

NHS Glasgow And ClyDE: No. of cases Results NHS Glasgow And ClyDE: No. of cases Left eyes: 13 Right eyes: 7 Bilateral: 2 22 patients: 7 M, 15 F Age: mean 35.8, range 18-59 * No. of cases up to July 2014 – total of 17 cases of AK diagnosed in 2014

Results Signs and Symptoms Pain: 95% Photophobia: 763% Foreign Body Sensation: 9% Tearing: 9% Decreased Corneal Sensation: 36% Additional History Poor hygiene: 2 Extended wear/ Slept in CL: 3 Use during swimming: 2 Type of Contact Lens Rigid Gas Permeable: 9% Soft monthly disposable: 40% Soft daily disposable: 31% Cosmetic: 4% Unknown: 14%

Additional Procedures - None Results EARLY FEATURES Misdiagnosis CL Related Keratitis: 75% Corneal Abrasion: 8% HSV Keratitis: 8% Fungal: 8% 55% Epitheliopathy Punctate Keratopathy Pseudo/True Dendrties Perineural Infiltrates Radial Keratopathy Delay in Diagnosis Range: 0-10 weeks Mean: 2.5 weeks Follow-up Visual Acuity Discharged: 25% 5-12 months Local follow up: 16% Range: 5-16 months Initial: Range 6/6 to 6/36 Visual outcome: Range 6/5 to 6/12 6/5 – 6/6: 82% 6/9 - 6/12: 18% 25% still on treatment Additional Procedures - None

Additional Procedures Results Misdiagnosis Delay in Diagnosis HSV Keratitis: 50% CL Related Keratitis: 40% Corneal Abrasion: 10% Range: 2-16 weeks Mean: 5.8 weeks Additional Procedures AMG: 50% PK: 40% Evisceration: 10% Visual Acuity Initial: Range 1/60-POL Visual outcome: Range: 6/5 to HM 6/5-6/9: 30% 6/12-6/36: 30% 6/60 or less: 40% 30% still on treatment LATE FEATURES 45% Follow-up Stromal infiltrates (Ring) Ulceration Anterior Uveitis Discharged: 30% 12-33 months Range: 14-60 months

Results Diagnosis METHOD SHIFT: Corneal Scrape/Biopsy to Confocal/PCR/Diagnosis 2009-2012: Early features: 15% Late features: 85% 2013-2014: Early features: 73% Late features: 27%

Results Treatment Duration of Treatment Early features: Range: 1-11 months Mean: 7 months Ongoing treatment: 40% Late features: Range: 5-36 months Mean: 14.6 months Ongoing treatment: 30% Biguanide – Polyhexamethylene biguanide (PHMB) 0.02% or Chlorhexidine 0.02% Diamidine – Propamidine Isethionate (Brolene) 0.1% or Hexamidine 0.1%

High Index of Suspicion conclusion Early diagnosis of AK has a better visual prognosis, therefore early clinical features should be considered in CL wearers Our study shows there is an emerging trend toward early diagnosis with the use of diagnostic methods such as PCR and confocal microscopy As AK is re-emerging there should be a very low threshold to implement these in high risk patients High Index of Suspicion Contact Lens Wearers Corneal Trauma Exposure To Contaminated Water/Soil Failure To Respond To First Line Treatment for Keratitis

references KH Cheng, SL Leung, HW Hoekman, et al. Incidence of contact-lens-related microbial keratitis and its related morbidity. Lancet 1999;354:181–5 B Clarke, A Sinha, N Dipak et al. Review Article Advances in the Diagnosis and Treatment of Acanthamoeba Keratitis. Journal of Ophthalmology 2014. JK Dart, VP Saw, S Kilvington . Acanthamoeba keratitis: diagnosis and treatment update 2009. Am J Ophthalmol 2009 148(4): 487-499. K Hiti, J Walochnik, C Faschinger, EM Haller-Schober, and H. Aspöck, “One- and two-step hydrogen peroxide contact lens disinfection solutions against Acanthamoeba: how effective are they?” Eye, vol. 19, no. 12, pp. 1301–1305, 2005 H Jasim, N Knox-Cartwright, S Cook, and D Tole, “Increase in Acanthamoeba keratitis may be associated with use of multipurpose contact lens solution,” British Medical Journal, vol. 344, Article ID e1246, 2012. S Kilvington, T Gray, J Dart, et al. Acanthamoeba Keratitis: The Role of Domestic Tap Water Contamination in the United Kingdom. Investigative Ophthalmology and Visual Science, Jan 2004 (45): 165 – 169 RV Lawande, SN Abraham, I John, and LJ Egler, “Recovery of soil amebas from the nasal passages of children during the dusty harmattan period in Zaria,” American Journal of Clinical Pathology, vol. 71, no. 2, pp. 201–203, 1979. J Naginton, PG Watson, TJ Playfair, J McGill, BR Jones, and AD Steele, “Amoebic infection of the eye,” The Lancet, vol. 2, no. 7896, pp. 1537–1540, 1974.). CF Radford, OJ Lehmann, JKG Dart. Acanthamoeba keratitis:multi-centre survey in England 1992–1996. Br J Ophthalmol 1998;82:1387– 92. CF Radford, DC Minassian, and JKG Dart, “Acanthamoeba keratitis in England and Wales: incidence, outcome, and risk factors,” British Journal of Ophthalmology, vol. 86, no. 5, pp. 536–542, 2002. DV Seal, CM Kirkness, HGB Bennett, et al and Keratitis Study Group. Population-based cohort study of microbial keratitis in Scotland: incidence and features. Contact Lens and Anterior Eye1999;22:49–57.) JK Stehr-Green, TM Bailey, GS Visvesvara. The epidemiology of Acanthamoeba keratitis in the United States. Am J Ophthalmol 1989;107:331–6.