OP-10 The rationale for the use of microbial keratitis drug delivery protocols

Introduction Currently there is only one evidence based and published microbial keratitis protocol, the TST (Topical, Systemic, and Targeted Therapy) protocol, which is for use for use in fungal keratitis. Treatment guidelines, without supporting evidence for outcomes are widely used but seldom audited for adherence and results. The current situation is exemplified by the widely disseminated American Academy of Ophthalmology Bacterial Keratitis Preferred Practice Pattern which reviews a swathe of publications but provides few details for the key decision making points in the treatment of bacterial keratitis other than choice of initial treatment. Key decisions are causative organism dependent and are required for the following: initial treatment; the application frequency for the intensive treatment phase and its length; how to reduce the intensive frequency to one specified for maintenance therapy until defined cure criteria are reached; the time point at which treatment failure should be considered requiring re-evaluation of both diagnosis and treatment; second line adjunctive or alternative topical/systemic antimicrobial therapy; use of adjunctive steroids both when being applied at baseline (point of diagnosis and start of antimicrobial therapy) or later; how to withdraw steroid; management of recurrences of infection or inflammation; when to use cross linking, photodynamic therapy or therapeutic keratoplasty. Evidence will be given to show how the use of such a detailed protocol has provided high cure rates in both fungal and protozoal keratitis and how such protocols can be expected to be of benefit to all colleagues managing both common and rare causes of keratitis.