PURPOSE: The objective of this study was to evaluate interleukin-6 (IL-6) tear concentration and clinical outcome in patients with moderate-to-severe bacterial corneal ulcers post autologous platelet-rich plasma (PRP) eye drop therapy. MATERIALS AND METHODS: This was a pre–post designed study involving 21 moderate-severe corneal ulcer patients who got autologous PRP eye drop. Subjects were got autologous PRP eye drop as adjuvant therapy. Patients with moderate-to-severe infectious bacterial corneal ulcers were included in this study. Tear sampling was performed before therapy using sterile Schirmer paper from conjunctival inferior fornix. PRP therapy was performed for 7 days. Data recording and tear sampling were then performed at day 0 (pre-PRP), day 7 (D+7), and day 14 (D+14) after PRP therapy. Data recording included presence of pericorneal injection, blepharospasm, size of corneal defects, and hypopyon. RESULTS: There was a decrease in IL-6 tear concentration by day 14 after PRP therapy ( P < 0.001). IL-6 concentration at day 7 after therapy (7525.67 ± 7092 pg/mL) tended to be lower before therapy (10,599 ± 6158 pg/mL), but not statistically significant ( P = 0.156). The size of corneal defects decreased significantly post PRP at day 7 ( P = 0.035) and at day 14 ( P = 0.001). There was a significant blepharospasm at day 7 ( P = 0.012) and day 14 ( P < 0.001). There was a significant pericorneal injection only at day 14 ( P = 0.002). There was no significant decreased hypopyon. CONCLUSION: There was a significant reduction in IL-6 tear concentration and clinical improvement in moderate-to-severe bacterial corneal ulcers which got autologous PRP eye drop as adjuvant therapy.