Post-vitrectomy dry eye: a prospective study of ocular surface changes and associated risk factors

PURPOSE: To evaluate the effect of pars plana vitrectomy (PPV) on dry eye signs and symptoms and identify associated factors. METHODS: This prospective study included 60 consecutive patients undergoing primary PPV. Dry eye was assessed preoperatively and at one and three months postoperatively using Schirmer test, tear break-up time (TBUT), corneal and conjunctival staining, tear osmolarity, and the Ocular Surface Disease Index (OSDI) questionnaire. RESULTS: Sixty patients (mean age 70.4 years; 67% female) were enrolled. Combined phaco-vitrectomy was performed in 43.7% of cases, and 78.3% received retrobulbar anesthesia. Mean Schirmer scores declined at one month compared with baseline (8.5 mm vs. 11.7 mm, p = 0.014) and returned toward baseline by three months. Inferior conjunctival lissamine green staining and lubricant use increased at one month (p = 0.039 and p = 0.014). OSDI scores remained unchanged at one month compared to baseline (p = 0.756) but improved at three months compared with baseline (25.4 vs. 32.5, p = 0.042). TBUT, superficial punctate keratopathy, and osmolarity did not demonstrate statistically significant changes. Older age correlated with lower Schirmer values at one month (r = - 0.427, p = 0.006). In multivariate analysis, operative duration was independently associated with greater SPK scores and lower TBUT values. CONCLUSIONS: PPV is associated with transient ocular surface alterations, most evident at one month postoperatively, with partial recovery by three months. Older age and longer operative duration are independently associated with greater susceptibility to postoperative dry eye. OSDI scores should be interpreted cautiously after retinal surgery, as visual recovery may influence reported symptoms.