Barbara Wimpissinger

25-gauge vs 20-gauge system for pars plana vitrectomy: a prospective randomised clinical trial.

Aim: To compare 25-gauge vs 20-gauge system for pars plana vitrectomy in a prospective, randomised, controlled clinical trial. Methods: Three-port pars plana vitrectomy was performed in 60 patients belonging to 2 groups. Evaluations were performed preoperatively, intraoperatively, during the first three postoperative days, at 1 week, and at 1 and 3 months. The main outcome measure was time for surgery, divided into duration of wound opening, vitrectomy, retinal manipulation and wound closure. Results: The total duration of surgery showed no significant difference between the groups (p = 0.67). The 25-gauge group showed significantly shorter duration of wound opening (p<0.001) and wound closure (p<0.001). In contrast, the vitrectomy duration was significantly longer in the 25-gauge group (p<0.001). Conjunctival injection and subjective postoperative pain showed significantly lower irritation in the 25-gauge group (p<0.001 for both). Conclusion: The 25-gauge vitrectomy system offered significantly improved patient comfort during the first postoperative week. The smaller surgical openings facilitated wound healing and minimised pain. Duration of surgery was comparable between the two systems—the shorter time needed for wound opening and closure in the 25-gauge group being equalised by the longer vitrectomy duration. Intraoperative as well as retinal manipulation and illumination caused more surgical difficulties using the 25-gauge system.

Choroidal blood flow and progression of age-related macular degeneration in the fellow eye in patients with unilateral choroidal neovascularization.

PURPOSE Cardiovascular risk factors such as smoking, hypertension, and atherosclerosis seem to play an important role in the development of choroidal neovascularization (CNV). Recent studies have also provided evidence suggesting that choroidal and retinal blood flow is decreased in patients with AMD. On the basis of these results, the hypothesis for this study was that lower choroidal blood flow is associated with an increased risk of CNV in patients with AMD. METHODS Forty-one patients with unilateral choroidal neovascular AMD were included in this observational longitudinal study. The fellow eyes of the patients served as study eyes. Subfoveal choroidal blood flow (FLOW) and fundus pulsation amplitude (FPA) were assessed with laser Doppler flowmetry and laser interferometry, respectively. A multivariate COX-regression model was used to test the hypothesis that low choroidal perfusion parameters are associated with the development of CNV. RESULTS Of the 37 patients that were followed up until the end of the study, 17 developed CNV and 20 did not. The univariate COX-regression analysis shows that lower FLOW, systolic blood pressure, intraocular pressure, and FPA are risk factors for development of CNV. Moreover, the more advanced the AMD in the study eye, the higher the risk for CNV to develop in the fellow eye. Multivariate COX regression analysis indicated that only FLOW (P = 0.0071), FPA (P = 0.0068), and staging (P = 0.031) had statistically significant influences on the progression to CNV. CONCLUSIONS The present study indicates that lower choroidal perfusion is a risk factor for the development of CNV in the fellow eye of patients with unilateral CNV.