Therapeutic DALK for acanthamoeba

Preventive DALK may be an effective therapy for refractory acanthamoeba infections, Enrica Sarnicola MD, Grosseto Italy, told the 2014 ASCRS annual meeting in Boston.

DALK was performed on 12 eyes with previous diagnoses of acanthamoeba keratitis, of which 3 had active infections. All eyes were unresponsive to medical treatment and procedures were performed within 30 to 60 days of symptom onset. Ulcers were 300 microns or less with ulcers greater than 150 microns deep in the optical zone, Dr Sarnicola said.

A cannula big bubble approach with manual dissection was employed in all cases, with graft diameter as large as possible; 8.5 mm in eight eyes and 9.0 mm in four eyes. Chlorohexadine gluconate was used as an antiseptic, propamidine isethionate as a DNA synthesis inhibitor and neomycin sulphate as protein synthesis inhibitor.

Histologic examination revealed cysts in removed stroma and 1.5 mm free peripheral margin, except in four cases, in which margins were not free in deep layers, Dr Sarnicola reported. However, no recurrence of infections was observed two years after surgery. Best corrected vision averaged 17/20, ranging from 14/20 to 20/20. No complications, such as secondary cataract or glaucoma were observed.

“DALK seems to be a very good procedure in acanthamoeba infections, both active and non-active,” Dr Sarnicola said. A larger series will be required to evaluate the success rate and possible late complications, she added.