Multidimensional review of viral infectious ocular diseases: Post-Pandemic epidemiology and future directions for...

Viral Infectious Ocular Diseases (VIODs) remain a major global cause of vision loss, ranging from highly transmissible conjunctivitis to blinding keratitis and complex neuro-ophthalmic syndromes. Furthermore, the Coronavirus Disease 2019 (COVID-19) pandemic and subsequent reported ocular diseases have fundamentally changed the landscape of VIOD epidemiology and management. Epidemiological data indicate heterogeneous effects on common infections such as Adenoviral conjunctivitis due to varying compliance with hygiene measures. Concurrently, systemic immunological events, notably those induced by COVID-19 infection or certain vaccinations, have been linked to the reactivation of latent Alphaherpesviruses, including Herpes Simplex Virus (HSV) and Varicella Zoster Virus (VZV). The metagenomic next-generation sequencing (mNGS) offers a significantly improved diagnostic yield (up to 92.7 % in some cohorts) for complex infectious keratitis compared to conventional methods, providing an unbiased tool crucial for timely, targeted treatment. Therapeutic challenges are defined by the persistent threat of antiviral resistance, primarily driven by mutations in the viral Thymidine Kinase (TK) gene. To overcome poor ocular bioavailability, novel drug delivery systems (NDDS), such as Acyclovir-loaded Niosomes and Cubosomes, show promise by enabling sustained drug release and enhanced corneal permeation. Effective future VIOD control requires a multi-pronged strategy integrating robust global surveillance, rapid deployment of advanced molecular diagnostics, and the clinical implementation of resistance-beating therapies delivered via optimized nanocarrier platforms. This review provides the current understanding of VIODs, focusing on the epidemiological shifts observed post-2020, advancements in molecular diagnostics, challenges posed by antiviral resistance, and the emergence of next-generation therapeutic strategies.