EVALUATION OF WOUND CLOSURE USING DIFFERENT INCISION TECHNIQUES WITH 23-GAUGE AND 25-GAUGE MICROINCISION VITRECTOMY SYSTEMS

To describe the anatomic and histopathologic outcomes using different incision techniques with transconjunctival 23-G and 25-G vitrectomy systems.New Zealand rabbits were randomized to either 23-G or 25-G vitrectomy surgeries using angled incisions and straight incisions. After pars plana vitrectomy, the cannulas were removed and 0.1% trypan blue was injected to evaluate for leakage. The animals were killed on day 7 and the eyes enucleated for gross analysis and histopathologic analysis by frozen section.Leakage of trypan blue was noted from 10.8% and 5.7% of straight and angled incisions, respectively. There was no difference between 23-G and 25-G incisions (8.3%). On gross examination, the 25-G system resulted in 58% and 24% open external wounds for straight and angled incisions, respectively (P = 0.04). The 23-G system resulted in 83% and 39% open external wounds with straight and angled incisions, respectively (P = 0.017). The average wound area after the 23-G surgery was 223.1 microm(2) and 115.7 microm(2) for straight versus angled incisions, respectively (P = 0.02). The average wound area formed after the 25-G surgery was 160.3 microm(2) and 85.2 microm(2) for straight versus angled incisions, respectively (P = 0.001).Outcomes were similar for 23-G angled incisions, 25-G straight incisions, and 25-G angled incisions.