Chronic Recalcitrant Bacterial Infection in Steroid Modified Interstitial (Stromal) Keratitis: Presentation and Management
Suksri Chotikavanich MD*, Nattaporn Tesavibul MD*, Mongkol Uiprasertkul MD**, Amornrut Leelaporn PhD***, Pinnita Prabhasawat MD*
Affiliation : * Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand *** Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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.
Material and Method: 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%).
Conclusion : 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.
Keywords : Steroid modified keratitis, Interstitial keratitis, Bacterial keratitis
