Risk factors and treatment outcome of recurrent acanthamoeba keratitis after corneal transplantation

Objective

To investigate the risk factors and treatment outcome of recurrent Acanthamoeba keratitis (AK) after corneal transplantation.

Methods

A serial case-observational study was carried out.Twenty-eight eyes of 28 patients with AK who underwent corneal transplantation in Shandong Eye Hospital from January 2012 to January 2019 were enrolled.All the eyes received corneal transplantation from failing to respond to topical and systemic anti-Acanthamoeba medical therapy, including 13 eyes that received penetrating keratoplasty (PKP) and 15 eyes that received lamellar keratoplasty (LKP). The corneal lesion was removed by a trephine with a diameter of 0.5 mm over infiltration area during PKP or LKP.The clinical features of recurrent AK were summarized, including recurrence time, site and signs, and the risk factors of AK recurrence were analyzed.Local and systemic anti-Acanthamoeba medical therapy was performed in all relapsed eyes, and secondary surgery was performed for the eyes with poor response to medication.The therapeutic outcome of recurrent AK was evaluated.The study adhered to the Declaration of Helsinki.This study protocol was approved by an Ethics Committee of Shandong Eye Hospital (No.201112).

Results

In the 28 eyes, 7 eyes (25%) appeared recurrent AK after keratoplasty, including 2 eyes after PKP and 5 eyes after LKP.There was no significant difference in the recurrence rate between the two methods (P=0.396). The recurrence rate of eyes that had used glucocorticoids drugs before operation was 57.14% (4/7), which was significantly higher in comparison with 14.29% (3/21) of eyes without glucocorticoids before surgery (P=0.043). The recurrence rate of eyes with ulcer diameter ≥8.2 mm was 50.00% (5/10), which was significantly higher than 11.11% (2/18) of eyes with ulcer <8.2 mm (P=0.036). The recurrent lesions began at the edge of implant bed accounted for 85.71% (6/7), and the recurrent lesions located below graft accounted for 14.29% (1/7). In 7 eyes with recurrent AK, 6 eyes were completely cured.Among recurrent AK eyes after LKP, 2 eyes were cured by long-term medical therapy, and 2 eyes were cured by extended-diameter LKP, and another 1 eye was cured by conjunctival flap covering surgery.One eye with recurrent AK after PKP was cured by extended-diameter PKP.

Conclusions

The risk factors of recurrent AK after surgery are application of glucocorticoids before surgery and big lesions.Recurrent AK after surgery is curable by individualized therapy targeting to different clinical characteristics.