Purpose: Amniotic membrane transplantation (AMT) has shown promising results as an antifibrotic agent in trabeculectomy. We aimed to evaluate the additional effect of AMT in MMC-augmented trabeculectomy. Patients and Methods: This retrospective study analyzed the results of the first 12 postoperative months of glaucomatous eyes submitted to Moorfields Safer Surgery Trabeculectomy with MMC alone (non-AMT group) compared to MMC and AMT (AMT group). Both groups were compared in terms of intraocular pressure (IOP), number of antihypertensive medications and need for surgical reinterventions. Absolute and relative success rates 12 months after surgery were defined as IOP < 18 mmHg, without and with the use of antihypertensive medications, respectively. Results: The analysis included 51 eyes of 45 glaucoma patients (29 eyes in the non-AMT group and 22 in the AMT group). Mean IOP decreased from 24.72± 5.11 mmHg and 26.86± 10.62 mmHg preoperatively in non-AMT and AMT groups to 12.86± 4.22 mmHg and 12.60± 4.43 mmHg, respectively, at 12 months (p = 0.84). Postoperative number of medications decreased significantly in both groups. Absolute success was seen in 71% of non-AMT eyes and 55% of AMT eyes (p = 0.46), whereas relative success was obtained in 14% and 30%, respectively (p = 0.55). Reinterventions were needed in 28% of the eyes (11 bleb injection/needling and 4 Ahmed tube implantation) in the non-AMT group and in 27% of the AMT group (10 bleb injection/needling and 1 Ahmed tube implantation) (p = 0.89). Conclusion: Trabeculectomy combined with MMC and AMT did not show better results than trabeculectomy with MMC alone.

The aim of this study is to analyze the operational efficiency of tourism firms using weights-restricted data envelopment analysis (DEA) in a mathematical optimization framework. The use of weight restrictions has been applied in several studies on efficiency and performance evaluation, in order to account for the decision maker's information. In this study, a nonstandard approach to operational efficiency evaluation is applied in an attempt to overcome certain limitations in tourism analysis- namely, the fact that the analyst may choose to consider only a few rather than all of the input variables. One of the main findings of this study is that total weight flexibility can lead to nonrational weights due to the fact that certain inputs are effectively ignored. Furthermore, total weight flexibility can result in too many units being assessed as efficient, reducing the discriminatory power of the model. This problem can be solved by applying weight restrictions. A first practical implication is that the weighted DEA model yields better efficiency estimations. Moreover, since a high number of efficient units could be considered an unrealistic result, the findings of this study demonstrate that the choice of weighted or restricted DEA model produces more accurate efficiency results.