Background <p>To investigate the correlation between the copy number of herpes simplex virus (HSV) DNA in the aqueous humor and specific clinical parameters, including anterior chamber reaction, topical steroid responsiveness and prognosis in individuals with endothelial herpes simplex keratitis (EHSK).</p> Methods <p>An analysis of clinical data from 62 patients from June 2021 to June 2024, with herpetic keratitis was conducted, encompassing demographic characteristics, anterior chamber reaction, topical steroid responsiveness and prognosis. The copy number of HSV DNA in the aqueous humor was quantified. Correlation analysis was employed to assess associations between viral load and clinical parameters.</p> Results <p>The high copy array group exhibited significantly higher anterior chamber cell count, anterior chamber flare level, corneal sensitivity compared to the control group. Additionally, the high copy array group showed a shorter time to resolution of inflammation after steroid treatment, higher likelihood of developing chronic HSV, and increased severity of corneal scarring. Correlation analysis revealed significant associations between the copy number of HSV DNA and various clinical parameters including anterior chamber reaction, topical steroid responsiveness and prognosis.</p> Conclusion <p>The study elucidates significant associations between the copy number of HSV DNA in the aqueous humor and clinical parameters in individuals with EHSK. The findings highlight the potential value of viral load assessment in guiding clinical decision-making, personalized management strategies, and improving outcomes for affected individuals.</p>