Ocular surface molecule after transconjunctival vitrectomy

Aim: To evaluate ocular surface molecules after transconjunctival pars plana vitrectomy (PPV). Methods: A total of 28 eyes of 28 patients who received PPV were examined. Tears (10 μl) were collected before and after 20-gauge PPV or 23-gauge PPV. The concentrations of interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12p70 and tumour necrosis factor (TNF)-α were measured. The concentrations of each cytokine before and after surgery were compared. The change ratios of each cytokine (post-/presurgery) between 20-gauge and 23-gauge PPV were compared. Results: IL-1β, IL-6, IL-8 increased after PPV (Wilcoxon rank sum test; IL-1 β, p=0.009; IL-6, p<0.001; IL-8, p<0.001), while the other cytokines did not. Among them, only IL-8 increased significantly in 20-gauge PPV than in 23-gauge PPV (p=0.01, Mann-Whitney U test). Multivariate analysis showed that 20-gauge PPV was a significant factor behind the increase in postoperative IL-8 (OR 5.21, 95% CI (1.46 to 18.55), p=0.018), but surgical time and simultaneous cataract surgery were not significant factors. Conclusions: The increase in inflammatory cytokine IL-8 in tear was significantly less after 23-gauge PPV than 20-gauge PPV, indicating that transconjunctival PPV is less invasive from the viewpoint of the ocular surface molecular biology. This information may be important when deciding the method of PPV.