Fire Ant Punctate Keratopathy: A Novel Diagnosis Based on Clinical and Anterior Segment Optical Coherence Tomography Findings

PURPOSE: To describe the ocular findings and the long-term outcomes of patients diagnosed with corneal injury due to little fire ants (LFAs). METHODS: This is a retrospective case series of patients evaluated with corneal injury due to LFAs from October 2015 to January 2018 at the Cornea Clinic in Meir Medical Center. Patients underwent anterior segment optical coherence tomography (AS-OCT) imaging during the follow-up. RESULTS: Four patients reported ocular contact with LFAs and presented to our department with unilateral, scattered, small, dense, round, bright white opacities in the anterior corneal stroma, which remained unchanged in appearance over time, despite topical antibiotic and steroid treatment. No inflammatory signs were noted in the anterior chamber. Follow-up was performed clinically using AS-OCT for periods of 9 to 26 months after the incidents. AS-OCT findings demonstrated small, subepithelial, hyperreflective foci at the level of the anterior stroma to a depth of 145 to 250 mum, with posterior shadowing that remained unchanged over time. These findings were well-correlated with biomicroscopy findings. CONCLUSIONS: LFA bites can cause long-lasting corneal injury in humans with characteristic clinical biomicroscopic findings. The corneal lesions do not respond to conventional topical treatment. AS-OCT imaging can be a useful modality for diagnosis and follow-up. Awareness by both patients and ophthalmologists of this clinical entity may be helpful in diagnosis and management.