[Study of infectious keratitis in corneal graft].

PURPOSE

This retrospective study was conducted to identify the associated risk factors and microbiologic spectrum in infectious keratitis (IK) after penetrating keratoplasty (PK).

METHODS

Medical records of 246 PK (corneal grafts for a 17-year period, 1980-1997) were reviewed to identify IK. Criterion for inclusion was IK in PK and positive corneal culture or smear Gram stain. PK indications, interval PK-IK, risk associations microbiologic study, complications, and final corneal graft clarity were reviewed.

RESULTS

The incidence reported was 4.8%, 12 cases of IK identified in 246 PK performed. The most common PK diagnosis was herpes simplex keratopathy. Potential risk factors have been categorized in :1- Local ocular (graft discompensation, therapeutic contact lens, suture-related), 2- Topical medication (corticosteroids and antibiotics) and 3- Systemic causes (diabetes mellitus). Time interval between PK-IK was 27.1+/-25.7 months (25% occurred within 12 months PK and suture complications were the main cause; 75% later than 12 months and corneal oedema and therapeutic contact lens the main late causes). Microbial spectrum: 66.6% cases were bacterial, Gram (+) organisms were predominantly involved (Streptococcus and Staphylococci) and the remaining cases were fungal (Candida). There was one case of infectious crystalline keratopathy due to Streptococcus Mitis. The prevalence of complications like evisceration and failure clear graft were 75%.

CONCLUSIONS

IK after PK is an uncommon (4.8%) but serious complication. It proves a major later form incidence, associated to graft discompensation and contact lens use. Gram (+) bacterial organism and fungi (Candida) were predominantly involved.