Keratoplasty for treatment of Acanthamoeba keratitis

To evaluate and compare the outcomes of therapeutic keratoplasty (TKP) and optical keratoplasty (OKP) in the management of medically unresponsive Acanthamoeba keratitis and post-keratitis scarring, respectively.

Retrospective, nonrandomized, comparative, interventional case series.

Thirty patients with Acanthamoeba keratitis treated at a single center.

Retrospective review of all cases of penetrating keratoplasty (PKP) or lamellar keratoplasty (LKP) performed for Acanthamoeba keratitis at a single center between January 1, 1980, and December 31, 2007. Inclusion criteria included histopathologic confirmation of Acanthamoeba organisms in the surgical specimen and at least 6 months of postoperative follow-up.

Postoperative complications, microbiological cure, graft survival, and visual acuity.

Thirty-one eyes of 30 patients met the inclusion criteria. This included 22 eyes (22 patients) that were initially treated with TKP (20 PKP/2 LKP) and 9 eyes (8 patients) treated with OKP (8 OKP/1 LKP). Of the 22 eyes treated with TKP, multiple keratoplasties (range, 2-6) were performed in 12 eyes (55%), whereas repeat keratoplasty was performed in only 1 eye (11%) treated with OKP (P = 0.004). Recurrent Acanthamoeba keratitis, glaucoma, early and late persistent epithelial defects, and endophthalmitis were more likely to occur after TKP than after OKP. A microbiological cure was achieved in all surgical cases. Among eyes treated with TKP, this required 1 keratoplasty in 14 eyes, 2 keratoplasties in 6 eyes, and 3 keratoplasties in 2 eyes. After the initial keratoplasty, Kaplan-Meier survivals after TKP were 45.5%, 45.5%, and 37.5% at 1 year, 5 years, and 10 years, respectively, compared with 100%, 100%, and 66.7%, respectively, after OKP (P = 0.004). The median visual acuity was 20/40 after TKP and 20/25 after OKP. Eyes treated with TKP were less likely to obtain visual acuity of 20/40 or better and more likely to have vision of 20/200 or worse.

Therapeutic keratoplasty can successfully treat medically unresponsive cases of Acanthamoeba keratitis, although multiple grafts may be required and the visual prognosis is guarded. Optical keratoplasty performed after resolution of active keratitis is associated with an excellent prognosis for both graft survival and visual outcome.

The author(s) have no proprietary or commercial interest in any materials discussed in this article.