title: Early- versus late-onset infectious keratitis after radial and astigmatic keratotomy: clinical spectrum in a referral practice.
abstract: OBJECTIVE
  To compare the clinical characteristics of early- versus late-onset keratitis after radial keratotomy (RK) and astigmatic keratotomy (AK).
  
  
  METHODS
  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.
authors.affiliation: Department of Ophthalmology, William Beaumont Hospital, Royal Oak, Michigan, USA.
authors.forename: D G
authors.initials: DG
authors.lastname: Heidemann
authors.forename: S P
authors.initials: SP
authors.lastname: Dunn
authors.forename: C Y
authors.initials: CY
authors.lastname: Chow
mesh_terms: D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000601:surgery*; D003315:Cornea / Q000382:microbiology / Q000473:pathology / Q000601:surgery; D003320:Corneal Ulcer / Q000382:microbiology* / Q000473:pathology; D015818:Eye Infections, Bacterial / Q000209:etiology / Q000473:pathology; D006801:Humans; D007646:Keratotomy, Radial / Q000009:adverse effects*; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000209:etiology / Q000473:pathology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D012017:Referral and Consultation; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000209:etiology / Q000473:pathology; D013211:Staphylococcus aureus / Q000302:isolation & purification; D014792:Visual Acuity