Endogenous Candida Endophthalmitis: An Update on Epidemiological, Pathogenetic, Clinical, and Therapeutic Aspects

Endogenous Candida endophthalmitis (ECE) is a rare intraocular infection that poses a significant clinical challenge due to its potential to cause permanent visual impairment. ECE is caused by Candida spreading to the uvea and the retina during candidemia, in absence of recent ocular trauma. Candida albicans is the species most frequently involved, although in recent years non-albicans species have been on the rise, with distribution differences depending on the geographical area. The diagnosis is primarily based on the presence of specific risk factors (especially recent surgical interventions, diabetes, and immunosuppression) and on the clinical presentation, which is usually highly suggestive. Among imaging techniques, optical coherence tomography (OCT), with the typical "rain-cloud" sign, has notably improved diagnostic capability. Laboratory tests performed on ocular fluids, instead, have low sensitivity, so they often do not contribute to the diagnostic process. Therapeutic strategies are primarily based on systemic antifungal therapy, mainly fluconazole and amphotericin B (AmB), accompanied by vitrectomy and intravitreal injections of voriconazole or AmB in cases of significant vitreous involvement. The increase in Candida species resistant to currently available antifungal drugs necessitates a more appropriate use of these medications as well as the development of new drugs capable of eradicating the most challenging infections. This review examines the existing literature on ECE, covering its epidemiology, pathogenesis, diagnosis, prognosis, and management approaches.