The effect of three intraoperative corneal wetting solutions on dry eye after cataract surgery

Objective To compare the effects of intraoperative corneal wetting by Croma, balanced salt solution (BSS), and hydroxypropyl methylcellulose (HPMC) on xerophthalmia after cataract surgery. Methods This prospective study included 79 patients (90 eyes) who were randomly assigned to a Croma corneal wetting properties group, balanced salt solution (BSS) group, or domestic hydroxypropyl methylcellulose (HPMC) group. Croma is a ophthalmological product to protect corneal epithelium, whose main ingredients is 2%HPMC. The solutions were applied to the ocular surface during the surgery to keep it moist. The following were measure pre-operatively and at 1, 7, and 30 days after cataract surgery, and the effect of each solution was assessed: objective scatter index (OSI) and the amplitude of OSI (OSI-A), tear break-up time (BUT), corneal fluorescein staining (CFS), Schirmer I test (SIt), and the ocular surface disease index (OSDI) questionnaire scores. Data were analyzed by repeated ANOVA or Kruskal-Wallis test. Results There were significant differences for OSI and SIt among the three groups (P<0.05). For OSI and SIt, the Croma group had significantly better results than the BSS group at post-operative days 1, 7, and 30 (all P<0.05). The Croma group had significantly higher SIt scores for tear secretion than the HPMC group at 7 and 30 days after surgery (P<0.05). Similar changes in trends were discovered with repeated measures analysis. BUT of the three groups all declined and revealed a significant difference among the pre- and post-operative (P<0.05). For the BSS group, several of the measured parameters were worse than the pre-operative values. On post-surgical day 1, SIt and OSI-A were worse (P<0.05 each), subjective complaints were worse on day 7 (P<0.05), and CFS was worse on day 30 (P<0.001). In the HPMC group, SIt and OSI-A increased significantly on post-operative day 1 (P<0.05). In the Croma group, and there was a slight increase in OSI-A and SIt at the same time. Neither CFS nor OSDI scores increased for either the HPMC or the Croma groups. Conclusion Both Croma corneal wetting properties and domestic HPMC were more beneficial than BSS for alleviating xerophthalmia after cataract surgery. The reduction of tear secretion and the increase in corneal epithelial staining were smaller in the Croma group than in the HPMC and BSS groups, and patients had less discomfort. Therefore, the Croma corneal wetting properties were significantly better than the others. Key words: Cataract extraction; Xerophthalmia; Corneal wetting properties; Stability of tear film; Tear secretion