Early- versus late-onset infectious keratitis after radial and astigmatic keratotomy: Clinical spectrum in a referral practice

Abstract Purpose To compare the clinical characteristics of early- versus late-onset keratitis after radial keratotomy (RK) and astigmatic keratotomy (AK). Setting Referral subspecialty practice. Methods This retrospective review comprised 19 patients with infectious keratitis after RK and AK. Early- versus late-onset groups were analyzed for predisposing conditions; infiltrate location, size, and depth; microbiologic data; and final visual outcome. Results Ten patients in the early-onset group developed keratitis within a mean of 7.4 days after surgery (range 3 to 14 days). Nine patients in the late-onset group developed keratitis a mean of 5.4 years after surgery (range 1.5 to 15.0 years). Staphylococcus aureus was the predominant organism in the early-onset group and Pseudomonas aeruginosa in the late-onset group. In the early-onset group, most infiltrates occurred in the paracentral aspect of the RK incision and extended to the middle or posterior stroma. In the late-onset group, most infiltrates occurred in the peripheral portion of the RK incision and were localized to the superficial stroma. A hypopyon was present in 7 of 10 ulcers in the early group and in 1 of 9 in the late group. Two patients in the early group developed endophthalmitis. Most patients in the late-onset group had incisional pseudocysts; 2 had other risk factors for keratitis. Final visual acuity was 20/40 or better in 7 of 10 patients in the early group and in 8 of 9 patients in the late group. Conclusions Early-onset corneal ulcers after incisional refractive keratotomy were usually paracentral and deep, whereas late-onset ulcers were usually peripheral and superficial. Despite the predominance of Staphylococcus and Pseudomonas in the early- and late-onset groups, respectively, a variety of organisms may be responsible for infections in keratotomy incisions.