Background: In microbial keratitis, infection of the cornea can threaten vision through permanent corneal scarring and even perforation resulting in the loss of the eye. A literature review was conducted by Karsten, Watson and Foster (2012) to determine the spectrum of microbial keratitis. Since this publication, there have been over 2600 articles published investigating the causative pathogens of microbial keratitis. Objective: To determine the current spectrum of possible pathogens implicated in microbial keratitis relative to the 2012 study. Methods: An exhaustive literature review was conducted of all the peer-reviewed articles reporting on microbial pathogens implicated in keratitis. Databases including MEDLINE, EMBASE, Scopus and Web of Science were searched utilising their entire year limits (1950-2019). Results: Six-hundred and eighty-eight species representing 271 genera from 145 families were implicated in microbial keratitis. Fungal pathogens, though less frequent than bacteria, demonstrated the greatest diversity with 393 species from 169 genera that were found to cause microbial keratitis. There were 254 species of bacteria from 82 genera, 27 species of amoeba from 11 genera, and 14 species of virus from 9 genera, which were also identified as pathogens of microbial keratitis. Conclusion: The spectrum of pathogens implicated in microbial keratitis is extremely diverse. Bacteria were most commonly encountered and in comparison, to the review published in 2012, further 456 pathogens have been identified as causative pathogens of microbial keratitis. Therefore, the current review provides an important update on the potential spectrum of microbes, to assist clinicians in the diagnosis and treatment of microbial keratitis.

Tuberculosis (TB) causes significant morbidity and mortality worldwide. Ocular manifestations of TB can lead to severe and sight-threatening complications. Initiating treatment in ocular TB with anti-tubercular therapy (ATT) may be necessary to prevent long-term visual complications. We present a case of the reactivation of bilateral multifocal choroiditis (MFC) in a patient with latent TB after commencing ATT. An asymptomatic 36-year-old Indian male was referred to an ophthalmologist with extensive inactive bilateral MFC close to his fovea despite no previous medical or ocular history. Latent TB was subsequently diagnosed via TB specific antigens and antibodies. After a period of stable observation without evidence of active eye or systemic disease, the patient was commenced on quadruple ATT with the aim of reducing the risk of visual loss with the MFC. However, after commencing treatment, MFC reactivation was observed. This settled with the addition of high-dose oral prednisone. The steroid was slowly weaned and ceased with the cessation of ATT. There have been no further episodes of active choroiditis since treatment was ceased. TB is a significant cause of mortality worldwide, and ocular manifestations can cause severe and sight-threatening complications in active and latent TB. The treatment of TB, however, may lead to further complications. We present the case of a visually asymptomatic patient with latent TB, with before and after fundal images, demonstrating the reactivation of the MFC after commencing ATT.

Introduction Worldwide, tuberculosis is the leading cause of death from an infectious disease. Ocular involvement can cause significant and permanent vision loss. Ocular manifestations of tuberculosis often present with visual symptoms. Asymptomatic ocular tuberculosis is uncommon and yet can have serious consequences if missed. Case report An immunocompetent 26-year-old Filipino man living in regional Australia who was diagnosed with active pulmonary tuberculosis and started on antitubercular therapy. He was referred to an ophthalmologist for baseline ethambutol screening to exclude pre-existing optic neuropathy. Despite having no visual symptoms, when examined, the patient had vision threatening occlusive retinal vasculitis. He was initially commenced on localised therapy via bevacizumab intravitreal injections and retinal photocoagulation. Following completion of antitubercular therapy, high dose prednisone was commenced and slowly tapered. Conclusions We present the case of an asymptomatic sight threatening occlusive vasculitis that was discovered on pre-treatment ophthalmology review. This case emphasises the need for referral for full ophthalmic screening in newly diagnosed tuberculosis to exclude vision-threatening complications.