Recent developments in vitreoretinal surgery have increased the need for suitable vitreous substitutes. A successful substitute should maintain all the physical and biochemical properties of the original vitreous, be easy to manipulate, and be long lasting. Substitutes can be gaseous or liquid, both of which have associated advantages and disadvantages related to their physical properties and use. Furthermore, new surgical techniques with smaller vitreoretinal instruments have driven the use of more viscous substitutes. In this review, we analyze and discuss the most frequently used vitreous substitutes and look ahead to future alternatives. We classify these compounds based on their composition and structure, discuss their clinical use with respect to their associated advantages and disadvantages, and analyze how new vitreoretinal surgical techniques have modified their use.

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Motivating human capital in knowledge‐intensive activities is a serious managerial challenge because it is difficult to link rewards to actions or performance. Firms instead might motivate knowledge workers by offering them opportunities to increase personal benefits (e.g., learning, satisfaction) through autonomy in the decision‐making process. Our model shows that firms can offer less autonomy in projects closer to their core business: Because firm specialization raises the value of the project's outcomes, it also increases the benefits for knowledge workers, who derive motivation even though they make fewer decisions to support their realization of personal goals. Projects farther from the core offer weaker firm contributions, so firms can motivate knowledge workers by allowing them to benefit from greater autonomy. We discuss several implications of our analysis. Copyright © 2013 John Wiley & Sons, Ltd.

Background: 3D heads-up visualization systems are aimed to improve the surgical experience by providing high-resolution imaging. Objective of our study is to analyze, over a long-time span, the grade of satisfaction and safety of day-to-day 3D surgery compared to standard surgery and to investigate the technical distinctiveness between the heads-up systems currently in use. Methods: In this retrospective observational case series. we reviewed all surgical records of our ophthalmology-dedicated operatory rooms since the arrival of 3D heads-up viewing system, in November 2017. In particular, we compared the procedural complications of 3D-equipped operatory room (3DR) with the standard microscope operatory room (2DR). Moreover, a satisfaction questionnaire was administered to those surgeons shifting on both rooms to test their preferences on seven specific parameters (comfort, visibility, image quality, depth perception, simplicity of use, maneuverability and teaching potential). Results: 5483 eye surgeries were considered. 2777 (50.6%) were performed in 3DR and 2706 (49.3%) in 2DR. Procedural complication rate was comparable in 3DR and 2DR, also when considering different subtypes of surgery. Twelve surgeons (100% of our surgery team) participated in our satisfaction survey, expressing highest satisfaction score for 3D when applied in retina surgery. For cataract surgery, 3D scored best in all the parameters except for facility in use and depth of field perception. Conclusion: Long-term day-to-day use of 3D heads-up visualization systems showed its safety and its outstanding teaching potential in all ophthalmic surgical subtypes, with higher surgeons confidence for retina and cataract surgery.

Research summary: This article studies strategic interactions between firms that form alliances to exploit synergistic benefits. Firms cooperate to create value, but they can also compete to capture value. Fundamental questions rarely addressed by strategy scholars relate to how the configuration of control over resources influences firms' strategies, the potential for termination, and the emergence of cooperation and trust. The formal results reveal crucial aspects of the interorganizational rent‐generating process and yield testable implications. With greater synergistic benefits, firms invest more, but they also compete more intensively to capture more value. With symmetric control, more value gets created, which limits the potential for termination, but also exacerbates the competition for value; from a relational perspective, this form of control augments the calculative rationale of cooperation and trust. Managerial summary: When forming an alliance to exploit synergies, firms engage in a complicated strategic interaction that is part cooperation and part competition. What happens when partner firms cooperate and invest to create value while competing and using costly adversarial tactics to capture value? The analysis reveals that with greater synergistic benefits, firms invest more in value creation, but the fear of opportunism pushes them to waste more resources on value capture tactics. The balance between value creation and value capture, and the possibility that the alliance is terminated depend on the configuration of control over resources. The analysis further reveals under what conditions there can be trust between the partners, such that they focus on value creation and avoid wasting resources in the competition for value. Copyright © 2016 John Wiley & Sons, Ltd.