title: Chronic recalcitrant bacterial infection in steroid modified interstitial (stromal) keratitis: presentation and management.
abstract: OBJECTIVE
  To report histopathologically proven bacterial infection manifested multifocal interstitial (stromal) keratitis (IK) with definite previous history of prolong topical steroid use. Standard managements of bacterial keratitis did not provoke enough benefit.
  
  
  METHODS
  A retrospective analysis of 19 eyes in 15 patients referred to Siriraj Hospital between 2004 and 2010.
  
  
  RESULTS
  Multifocal intrastromal infiltration, with relatively quiet ocular reaction and mild inflammation were initially presented in all eyes. They all previously had been diagnosed of presumed viral keratitis, and had been given topical corticosteroid treatment for a prolonged period of time without healing. Autoimmune disease workups were all negative. Corneal scrapings showed negative culture results in all eyes. However, bacteria within stromal lamellae with absent or minimal inflammatory cells were demonstrated in all eyes by corneal biopsies. In addition, cytology results obtained from 16S rDNA sequencing revealed Stenotrophomonas maltophilia in one eye and coagulase-negative staphylococci in two eyes. No case responded well to intensive topical and systemic antibiotics. However they were successfully treated with penetrating keratoplasty (11 eyes, 57.9%) or intrastromal antibiotic injections (8 eyes, 42.1%).
  
  
  CONCLUSIONS
  Bacterial infection should be a concern in prolonged chronic IK. This was considered as primary bacterial IK or bacterial superinfection in immunocompromised cornea. Early recognition and appropriately aggressive managements contribute to successful outcome. Corneal biopsy is always essential and 16S rDNA sequencing is useful in this distinct clinical entity.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. sisuksri@mahidol.ac.th
authors.forename: Suksri
authors.initials: S
authors.lastname: Chotikavanich
authors.forename: Nattaporn
authors.initials: N
authors.lastname: Tesavibul
authors.forename: Mongkol
authors.initials: M
authors.lastname: Uiprasertkul
authors.forename: Amornrut
authors.initials: A
authors.lastname: Leelaporn
authors.forename: Pinnita
authors.initials: P
authors.lastname: Prabhasawat
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001706:Biopsy; D002908:Chronic Disease; D003131:Combined Modality Therapy; D015818:Eye Infections, Bacterial / Q000175:diagnosis / Q000382:microbiology* / Q000628:therapy*; D005260:Female; D006801:Humans; D007634:Keratitis / Q000175:diagnosis / Q000188:drug therapy* / Q000382:microbiology*; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013210:Staphylococcus / Q000302:isolation & purification; D020615:Stenotrophomonas maltophilia / Q000302:isolation & purification; D013256:Steroids / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D000900:Anti-Bacterial Agents; D013256:Steroids