Abstract
OBJECTIVE: This study aims to explore the correlation between ocular surface parameters and the location of lacrimal duct obstruction. METHODS: This retrospective comparative study included 74 patients (94 eyes) diagnosed with lacrimal duct obstruction (LDO) between December 1, 2022, and October 1, 2024. Based on the obstruction site, affected eyes were classified into an upper LDO group (29 eyes) and a lower LDO group (65 eyes). We collected ocular surface parameters, including mean non-invasive tear breakup time (NIBUT), Sjögren's International Collaborative Clinical Alliance Ocular Staining Score (SICCA OSS), and Korb scores for the lid wiper. A comparative analysis was performed to evaluate differences in these parameters between the two groups. RESULTS: Significant differences were observed in NIBUT and SICCA OSS between the two groups (P(NIBUT)=0.037, P(SICCA OSS)=0.010). Based on cutoff values, NIBUT was categorized into three intervals: ≤5 s (NIBUT1), 5-10 s (NIBUT2), and > 10 s (NIBUT3). A higher proportion of eyes with lower LDO fell into the NIBUT1 group (P < 0.05). Similarly, SICCA OSS was graded into three categories: SICCA.1 (≤ 1 point), SICCA.2 (1-2 points), and SICCA.3 (> 2 points). The distribution of SICCA OSS grades differed significantly between groups (P = 0.009). The SICCA.2 group contained a higher proportion of upper LDO eyes (P < 0.05), while the SICCA.1 group had more lower LDO cases (P < 0.05). The Korb score was also divided into three tiers: Korb1 (≤ 1 point), Korb2 (1-2 points), and Korb3 (> 2 points). Intergroup differences in Korb tier distribution were significant (P = 0.045), with the Korb3 group containing a higher proportion of upper LDO eyes (P < 0.05). CONCLUSION: The location of obstruction is associated with distinct ocular surface phenotypes. Upper LDO is linked to more severe ocular surface and lid margin damage but relatively preserved tear film stability. Lower LDO is characterized by more profound tear film instability. Therefore, surgical management should be tailored accordingly: procedures for upper LDO should be approached with caution, while prompt intervention is recommended for lower LDO presenting with epiphora.