Ophthalmic manifestations of Cryptococcus gattii species complex: a case series and review of the literature

AIM: To report 4 cases of Cryptococcus gattii (C. gattii) species complex infection with diverse ophthalmic manifestations, and to review the literature to examine pathobiology of disease, classical ophthalmic presentations and outcomes, and treatment modalities for this emerging pathogen. METHODS: Cases of C. gattii meningoencephalitis with ophthalmic manifestations were identified via chart review at two institutions in Australia and one institution in the mid-west region of the United States and are reported as a case series. Additionally, a MEDLINE literature review was conducted to identify all reported cases of C. gattii with ophthalmic manifestations from 1990-2020. Cases were reviewed and tabulated, together with our series of patients, in this report. RESULTS: Four cases of C. gattii with ophthalmic manifestations are presented; three from Australia and one from the USA. A literature review identified a total of 331 cases of C. gattii with visual sequelae. The majority of cases occurred in immunocompetent individuals. Blurred vision and diplopia were the most common presenting symptoms, with papilloedema the most common sign, reported in 10%-50% of cases. Visual loss was reported in 10%-53% of cases, as compared to rates of visual loss of 1%-9% in C. neoformans infection. Elevated intracranial pressure, cerebrospinal fluid (CSF) fungal burden, and abnormal neurological exam at presentation correlated with poor visual outcomes. The mainstays of treatment are anti-fungal agents and aggressive management of intracranial hypertension with serial lumbar punctures. CSF diversion procedures should be considered for refractory cases. Acetazolamide and mannitol are associated with high complication rates, and adjuvant corticosteroids have demonstrated higher mortality rates; these treatments should be avoided. CONCLUSION: Permanent visual loss represents a devastating yet potentially preventable sequelae of C. gattii infection. Intracranial hypertension needs to be recognised early and aggressively managed. Referral to an ophthalmologist/neuro-ophthalmologist in all cases of cryptococcal infection independent of visual symptoms at time of diagnosis is recommended.