Reduced need for corneal epithelial debridement during vitreo-retinal surgery using two different viscous surface lubricants

PURPOSE: Corneal clarity is frequently reduced during vitrectomy and scleral buckling surgery secondary to epithelial edema, requiring epithelial debridement to improve visibility. The presence of toxic preservatives in the corneal lubricant solutions is hypothesized to be a contributing factor to epithelial edema during vitreo-retinal surgery. DESIGN: Interventional study. METHODS: We compared prospectively the corneal clarity and epithelial debridement frequency in 71 patients within a single institution in whom either Goniosol (2.5% methylcellulose, boric acid, edetate disodium, sodium borate, potassium chloride, water, and 0.01% benzalkonium chloride) or GenTeal gel (0. 3% hydoxypropyl-methylcellulose, carbopol 980, phosphonic acid, sorbitol, water, and 0.028% sodium perborate) was used as a corneal lubricant during the course of vitrectomy surgery using sutured contact lenses. Corneal clarity was subjectively graded in a scale of I to IV during surgery. Statistical analysis was made between these two groups for parametric and categorical data. RESULTS: All eyes started with a corneal clarity grade of I (best possible). Corneal clarity decreased significantly faster in eyes where Goniosol was used to a median grade of III at 1 hour of surgical time. In eyes where GenTeal gel was used, corneal clarity decreased much slower, to a median grade of I at 1 hour of surgical time. The difference in frequency of epithelial debridement was also statistically significant: 54% and 14% for Goniosol and GenTeal eyes, respectively. Other factors that may cause corneal epithelial edema and affect corneal clarity were not statistically different between the Goniosol and the GenTeal groups, including median operative time, estimated intraocular pressure, pre- and intraoperative topical solutions and medications, and number of prior ocular procedures. CONCLUSIONS: The use of GenTeal gel as a corneal lubricant maintains corneal clarity longer than Goniosol during the course of vitrectomy surgery using a contact lens viewing system, limiting the need for epithelial debridement.