1. A 12 year history of Chronic, Culture-confirmed Acanthamoeba Keratitis
Elmer Y. Tu, MD
Joel Sugar, MD
Charlotte E. Joslin, PhD
Lisa M. Nijm, JD, MD
The authors have no financial interest in the subject matter of this poster

2. Purpose
To report a case of chronic, recalcitrant Acanthamoeba keratitis (AK) persisting for over 12+ yrs.

3. Clinical Presentation (12/27/1995)
32 y.o female physician contact lens wearer seen in consultation at the University of Illinois Eye and Ear Infirmary (IEEI) for chronic keratitis of the right eye of 2 years duration.
Herpetic keratitis 1989 OD
Recurrent dendritic disease 1994
Dendritic disease resolved with topical trifluridine alone
Development of persistent stromal edema, subsequent immune ring
June 1995 – Recurrence tx with topical corticosteroids, trifluridine.
Persistent inflammation required continued medications as above. Oral acyclovir was added 200 mg q.i.d.

4. Clinical Presentation (12/27/1995)
OS Normal
OD VA 20/40-2
Slit lamp examination
Mild central stromal edema
Fine KP over the central corneal endothelium
AC quiet
Partial, superficial anterior stromal immune crescent extending between 3 and 7 o’clock paracentrally.

5. Clinical course Waxing and waning course of corneal inflammation
Visual acuity fluctuates between 20/20 and 20/50.
Chronic very low dose topical corticosteroids and occasional trifluridine
Referred to the University of Iowa
Confocal microscopy and epithelial biopsy performed
Acanthamoebae identified

6. Clinical course Initial anti-acanthamoebal treatment
Chlorhexidine 0.02% Q2h for 3 weeks
Continued for 11 months Q2-qid dosing.
Discontinued because of pregnancy
Maintained on topical steroids
Subsequent 8 years
Extended treatment with topical chlorhexidine, polyhexamethyl biguanide (PHMB), desmodine, oral itraconazole without significant change in inflammatory recurrences or activity.
Visual acuity largely maintained 20/20-20/25 BSCVA
Intact endothelium
Stromal haze, scarring No organisms appreciated
2001 Nidek Confoscan 2

7. Clinical Course
Follow up at an outside facility without change in therapy
November, 2006
Increasing severity and frequency of episodes of inflammation
Prednisolone acetate 1% Q1h
Decreasing vision – 20/60
Corneal thickness – 576 OD, 618 OS
IOP normal
Slit lamp examination – Large KP, moderate corneal haze

8. Intervention
Vision declined to 20/200 despite hourly topical corticosteroids, topical chlorhexidine, oral voriconazole
Full thickness Penetrating keratoplasty
Pathology – endothelial cell attenuation, stromal infiltration
No organisms seen
Culture – Positive for acanthamoeba
Microcystic epithelial edema
Acanthamoeba cysts in deep stroma – bright centered thick walled structures (arrow)
2006 Nidek Confoscan 3

9. Follow-up August, 2009 Visual acuity BSCVA 20/30
Topical loteprednol QD
No adjunctive anti-acanthamoebal therapy
No further episodes of inflammation

10. Discussion
To our knowledge, our patient represents the longest sustained corneal infestation with recoverable Acanthamoebae reported to date.
The stromal inflammation seen in our patient is not uncommon in AK, but usually subsides with preferred therapy which our patient received for years often at high sustained frequencies.
Indicates that this organism was clinically resistant
Persistence of inflammation has been suggested to represent either persistent infection, reported lasting a year or more, or a sterile reaction to persistent amoebic antigens.

11. Discussion Persistence of infection is not surprising.
Acanthamoebal cysts may survive in harsh environments, remaining viable for decades.
Host immune response is likely ineffective in aiding clearance of Acanthamoebae
The use of corticosteroids has not been associated with poorer outcomes in AK, and it is unclear what role it may have had here, but was successful in maintaining ~ 20/25 vision for over a decade

12. Conclusion
Clinicians need to be aware that AK may manifest as a chronic recurrent stromal keratitis lasting >10 years
Chronic, persistent inflammation should not be interpreted as sterile until otherwise proven
Course further mimics HSV keratitis
May also coexist with HSV keratitis
Should be suspected in any at-risk individuals with this clinical picture
Contact lens wearers
Confocal microscopy has adjunctive utility in deep AK
Identified both at epithelial and deep stromal stage
Surgical intervention may be necessary and curative when medical therapy fails
Oral voriconazole was added late, earlier, more aggressive medical therapy may be indicated