Abstract
Purpose: :
Management of Acanthamoeba keratitis (AK) is often challenging. The purpose of this study is to determine the potential advantage of in vivo confocal microscopy (IVCM) for both diagnosis and management of AK on patient outcome, as compared to conventional means.
Methods: :
A retrospective, single-institution, comparative case study of AK cases comparing outcomes in patients a) diagnosed by corneal culture and followed clinically (conventional), b) diagnosed by IVCM and followed clinically (confocal-diagnosed) and c) diagnosed and followed with serial IVCM (confocal-guided).
Results: :
A total of 23 patients (26 eyes) with a final diagnosis of AK and at least 3 months follow-up were included from a total of 32 patient records reviewed, including 6 conventional, 9 confocal-diagnosed, and 11 confocal-guided eyes. The mean days to diagnosis was significantly longer in the conventional group (29 ± 33) as compared to the confocal groups combined (5 ± 6; p=0.007). The mean visual acuity (VA) in each of the 3 groups was 20/800, 20/60 and 20/125 at presentation; 20/125, 20/70 and 20/100 at 1 month; 20/800, 20/30 and 20/50 at 3 months; 20/800, 20/30 and 20/40 at 6 months; and 20/200, 20/25 and 20/25 at last follow-up. VA between conventional and confocal groups was significant (p<0.05) at 3 months, 6 months, and final follow-up, although not between the confocal groups. Therapeutic penetrating keratoplasty (PK) was performed in 4 of 6 conventional eyes (67%) with mean final VA of 20/200, 3 of 9 confocal-diagnosed eyes (33%) with mean final VA of 20/25, and 1 of 11 confocal-guided eyes (9%) with mean final VA of 20/20. PK graft failure occurred in 3 of 7 non-confocal cases. In the 2 confocal groups, none of the grafts failed.
Conclusions: :
Our data demonstrate that the use of IVCM in the diagnosis of AK reduces the number of days to diagnosis, expediting initiation of therapy, and leading to excellent visual outcome. In addition, these data suggest that confocal-guided treatment results in a decreased number of patients needing a therapeutic PK.
Keywords: keratitis • Acanthamoeba • imaging/image analysis: clinical