<b>Correlation between allergic conjunctivitis and changes in tear film lipid layer and meibomian gland function</b>

Objective: To investigate the correlation between allergic conjunctivitis (AC) and changes in tear film lipid layer (TFLL) and meibomian gland (MG) function. Methods: The clinical data of 96 patients with AC treated at our hospital from June 2022 to March 2023 and 72 healthy individuals who underwent physical examination in our hospital during the same period were analyzed retrospectively. Among them, 96 patients with AC were included in the study group, while 72 healthy individuals were included in the control group. Eyes selected for study from participants were the left eyes or one single eye that met the selection criteria. The TFLL thickness, MG score, MG secretion character score, and ocular surface disease index (OSDI) score were compared between the study group and healthy control group. Patients in the study group were further categorized into a mild group and a severe group based on their OSDI scores. The TFLL thickness, MG score, and MG secretion character score were then compared between these two groups. Additionally, the correlations of TFLL thickness, MG score, and MG secretion character score with OSDI were analyzed. The diagnostic value of TFLL, MG score, MG secretion character score and combination of the three in diagnosing AC was evaluated. Results: Compared to the control group, the study group showed significantly thinner TFLL and got significantly higher MG score, MG secretion character score and OSDI score (P&lt;0.0001). The TFLL thickness showed a negative correlation with OSDI score (r=-0.7149; P&lt;0.0001). Conversely, both MG score (r=0.5585; P&lt;0.0001) and MG secretion score (r=0.4390; P&lt;0.0001) demonstrated a positive correlation with OSDI score. Furthermore, the mild group showed significantly thicker TFLL than the severe group (P&lt;0.0001), and got significantly lower MG score and MG secretion score than the severe group (P&lt;0.0001). The area under the curve (AUC) values of TFLL thickness, MG score, and MG secretion score in the diagnosis of AC were 0.869, 0.834, and 0.738, respectively, and the AUC of the combination of these three in diagnosing AC was 0.922. Conclusion: AC is strongly bound up with TFLL and MG function. The combination of TFLL, MG score, and MG secretion score can be adopted for effective diagnosis of AC.