We thank Dr. Coppola et al for their comments on our paper “Heads-up Surgery for Vitreoretinal Procedures: An Experimental and Clinical Study.”1 We learn from their letter to the editor that Dr. Coppola et al do not share our opinion on the ergonomic benefits of heads-up surgery, but rather see no real difference to traditional microsurgery in this regard.
Obviously, there is a large subjective component to judgments about ergonomics. We are well aware that the current 3D system with the display placed on the patient's right or left side could be improved, but this is often constrained by the support structures of the microscope and surrounding equipment. It certainly would be better to position the display directly in front of the surgeon, i.e., above the patient's body, so that the surgeon no longer needs to turn his or her head or neck or upper body approximately 15° laterally for viewing the screen. In our opinion, however, this is a minor drawback because looking at a large display—even if it is positioned somewhat off axis—allows for much more movement of the eyes, head, neck, shoulders, and body than does looking through oculars. During surgery, we frequently change our sitting position sideways as well as backward and forward. Sometimes, we adopt an upright posture, and sometimes we find ourselves in a slightly bent-forward position as in traditional microsurgery, but often, we prefer to lean slightly back because our operating chair is equipped with an optimal backrest with lordosis support. Such relaxing variations of posture are not possible when looking through oculars.
There is no question that the ergonomics during microsurgery can play an important role for the attitude and health of the surgeon. It was, however, not the main goal of our study to investigate this issue quantitatively in the same way that we tried to investigate other (and in our opinion, more interesting) factors that have an impact on heads-up surgery, such as resolution, depth of field, and image enhancement. When we performed our study in 2014, we were fascinated to see how a lower-light image could be brightened by electronic amplification of the camera signal. As mentioned in our paper, we were at that time not particularly impressed by the limited options then available for image enhancement, such as manipulating contrast and color. After 3 years of experience with the 3D system, we still improve the visualization of certain structures mainly by changing the brightness and increasing the magnification. However, we are aware of recent, and more sophisticated, developments in image enhancement and look forward to being able to evaluate and report on them.