RESUMO
PURPOSE: Microbial keratitis (MK) is a serious sight-threatening complication occurring with and without contact lens wear. The task of diagnosing MK is difficult because each presentation of the disease is different and can be mistaken for noninfectious ulcers such as contact lens peripheral ulcer (CLPU). The purpose of this article is to present a case report of MK initially diagnosed as a CLPU. CASE REPORT: We report the incidence of a 21-year-old female presenting with signs and symptoms in her left eye, which initially suggested a CLPU. At the 24-h follow-up, contrary to expected indications of healing, her condition had deteriorated. The diagnosis was reevaluated as an MK. Ciloxan was prescribed under care of an ophthalmologist. Despite initial misdiagnosis, due to aggressive topical treatment and the peripheral location of the lesion, <1 line of vision was lost. DISCUSSION: Defined signs and symptoms criteria have been established for the differential diagnoses of MK and CLPU. However, there is often an overlap in the signs and symptoms that can complicate the diagnosis. A critical sign, however, is progress immediately after lens wear is discontinued. Prophylaxis and rapid appropriate treatment and follow-up are vitally important if there is any doubt and to ensure correct diagnosis and resolution. CONCLUSION: Any diagnosis of CLPU must be monitored carefully to ensure it is not MK. Prompt diagnosis and treatment of MK are essential for a good visual outcome.