Fungal endophthalmitis is a chronic inflammatory condition
of the
eye’s posterior segment that can lead to irreversible vision
loss. While relatively rare in western countries, its incidence is
notably higher in Asia, particularly India. The condition’s
prevalence is exacerbated by factors such as intravenous drug use,
antibiotics, and ocular surgeries. Fungal endophthalmitis can be categorized
as endogenous, arising from systemic infection, or exogenous, linked
to external sources such as trauma or surgery. The fungal agents responsible
vary by region, with Candida species common in the
West and Aspergillus and Fusarium species more prevalent in India. Management typically involves vitrectomy
and intravitreal antifungal drugs such as amphotericin B and voriconazole,
though treatment is often complicated by multidrug resistance and
culture-negative cases. Recent proteomic and transcriptomic analyses
have highlighted the early and sustained activation of the host immune
response during infection involving key inflammatory and oxidative
stress-related proteins. Given the potential for excessive inflammation
to cause retinal damage, targeted immunotherapies are crucial. Immunomodulation,
which aims to balance the immune response, shows promise in preserving
vision while effectively combating the infection. Key targets for
immunomodulation include pro-inflammatory cytokines (TNF-α,
IL-1β, IL-6, IL-17), chemokines (CCL2, CXCL8), Toll-like receptors
(TLR2, TLR4), and the complement system. Additionally, modulating
the activity of macrophages, neutrophils, regulatory T cells, and
Th17 cells, as well as targeting inflammasomes, can help control inflammation.
Biologic agents and small molecule inhibitors offer further avenues
for precise immune response modulation. This review underscores the
importance of a comprehensive understanding of host–pathogen
interactions in the development of effective therapies for fungal
endophthalmitis.