Microbial Keratitis After Intrastromal Corneal Ring Segment Implantation

Abstract

PURPOSE:To evaluate the incidence of acute microbial keratitis after intrastromal corneal ring segment implantation and to investigate whether microbial keratitis is related to the intrastromal corneal ring type or surgical technique. METHODS:Intrastromal corneal ring segments were implanted in 212 eyes of 149 patients. Two different types of intrastromal corneal ring segments were used during the study, Intacs and Ferrara rings, and two surgical techniques were used for intrastromal corneal ring segment implantation, manual and femtosecond laser. RESULTS:One hundred thirty-four eyes (63.2%) underwent Intacs implantation and 78 (36.8%) eyes received Ferrara rings. Corneal tunnels were created using the manual technique in 119 (56.1%) eyes and by femtosecond laser in 93 (43.9%) eyes. Three cases (1.4%) of acute microbial keratitis were clinically identified. Cultures were positive in 2 eyes and negative in 1 eye, and polymerase chain reaction was positive in all 3 cases. The microorganisms isolated from cultures were Streptococcus mitis and Staphylococcus aureus. In 2 cases, the femtosecond laser technique was used (1 eye Intacs, 1 eye Ferrara), and in 1 case, the manual technique was used (Intacs). No statistically significant difference was noted between techniques (P=.582) or segment type (P=1.000). In all cases, intrastromal corneal ring segments were explanted and intensive topical antibiotics were used with clinical success. CONCLUSIONS:Acute microbial keratitis incidence after intrastromal corneal ring segment implantation was 1.4%. Gram-positive cocci were the organisms isolated more frequently. Proper management of this condition requires intrastromal corneal ring segment explantation and intensive topical antibiotics. [J Refract Surg. 2010;26:364–369.]