•The circulator who accepts the patient in the OR cross-checks and confirms this.

–She also confirms that the eye is correctly indicated on the operating list.

•The person administering the local anesthesia cross-checks the mark and has it verbally confirmed by the patient.24

•The nurse at the operating table checks the mark on the patient’s forehead.

–If the surgery is under local anesthesia, the patient must verbally confirm that the correct eye has been prepped.

•The surgeon must have the final confirmation by the nurse and the wake patient.

The surgeon must remind the patient25 of what also has been discussed before. This should cover all intraoperative issues (see Sect. 15.2) as well as postoperative positioning, the loss of vision if air/gas tamponade is used etc.

16.7The Surgeon

There are numerous items on this checklist. With time, they should become (a) routine for surgeon and OR personnel.

16.7.1 The Posture (Ergonomics)26

One of the most common errors the beginner surgeon commits is trying to adjust his own position/posture to the microscope, operating table, and chair. You must do the exact opposite.

Pearl

You should sit comfortably in your chair, adjusting it (height, armrest) first. Next, adapt the height of the microscope to your position as you are sitting comfortably (neck position, lower back; see below). Finally, adjust the operating table to the microscope’s height – but remember, patients have different head sizes and orbital architectures. The height of the operating table must be readjusted to accommodate these individual variations, not your posture.

The initial settings are to be done before scrubbing in.

•Adjust the chair’s height to your comfort.

–Your legs should reach the floor without having to stretch or knee-bending: your thighs should be fairly parallel to the ground when your feet are rested on the pedals, which should already have been placed under the operating table (see Sect. 16.3).

24“Which eye will you have surgery on?” is a better way of asking than “is it your right eye that is going to have surgery?”.

25If the operation is performed under local anesthesia.

26Do not blindly follow the recommendations outlined here but think about these issues and find the best posture for yourself.

•Adjust the arm support’s height to the length of your upper arm.

–A roughly 90° angle between your upper and lower arms is the least stressful position.

With the chair set, roll the microscope in place, and adjust its height.

•When looking into the eyepieces, your back should be fairly straight without having to stretch.

–Too high a microscope will result in extra strain on your back muscles.

•Your neck should be as vertical as possible.

–Bending the neck is very likely to lead to aching, even short term; longer term even disc hernia threatens.27 The microscope’s eyepiece should be angled (tilting; see Sect. 12.2) so that your neck need not be stretched nor bent more than a few degrees.

•Adjust the pupillary distance.

•Adjust the focus separately for each eye (remember to take the video camera into account; see Sect. 12.4).

–Do this under high magnification and by looking at a small object that is immobile.28

The subsequent settings should be done after scrubbing in.

•Have the patient comfortably lying on the operating table, in his “final” position (see Sect. 16.6).

•If the operating table is equipped with a “U”-shaped wrist support, its height must be adjusted to the individual patient’s physical features.

•Swing in the microscope and adjust the table height to the specific microscope height you already determined.

•The pedals must be at an angle that is comfortable for the surgeon.29

–Their distance from the surgeon must be “not too far and not too close,” maintaining the lower leg’s ~90° angle to the floor as well as allowing easy access/ comfortable manipulation.

•No cables should be caught underneath the pedal.

To ensure that the surgeon maintains comfortable position/posture during vitrectomy is not simply a matter of convenience. It helps him preserve his musculoskeletal health and allows him to concentrate on the surgical tasks rather than on his aching body. For the same purpose, if the surgeon is able to do some stretching inbetween operations, this is of great value.

27Do not dismiss this warning easily. It is a very dangerous condition that can require emergency surgery, which is risky and has a long recovery time even if successful.

28This can also be done later, when the patient is already on the table and the speculum is in situ. Find a blood vessel in the conjunctiva and use that one as a target for both eyes, without changing any setting on the microscope other than the eyepiece (diopters) itself.

29I prefer if their distal end is turned outward at a ~15° angle (see Fig. 16.3).

Pearl

Maintaining poor posture for extended periods is like smoking: when it occurs, it usually causes no or only temporary complaint. The microtraumas add up, though, but by that time the damage is irreversibly done.

The height of the microscope has been focused to the eye’s external surface. During PPV the microscope must be readjusted in two scenarios so that the retinal image is in focus: when the BIOM is swung in and when switching to a contact lens. The refocusing requires only a few centimeters in vertical adjustment,30 but the surgeon still needs to reevaluate whether these height differences justify readjustment of the operating table and chair.31

There are three additional factors to consider when determining the need for the readjustment.

•The duration of the intraocular procedure.32

•The need to alternate between procedures in the AC vs in the posterior segment.

•Whether frequent switching between the contact lens and the BIOM will be needed.

16.7.2 At the Start of Vitrectomy

•Hold the light pipe in the nondominant and the probe in the dominant hand (see

Fig. 16.6).

•With the dominant foot, zoom out fully and readjust the focus if necessary.

•Place the dominant foot’s heel on the support bar (see Fig. 12.3) and have the toes over the X-Y joystick. This position is to be maintained throughout surgery, unless the focus or zoom buttons need to be used.

–During PPV, the surgical field is often changed as you move the microscope to view different areas in the vitreous cavity. To avoid losing the image, simultaneously rotate the eye with both intravitreal instruments as you adjust the microscope’s position with the X-Y joystick (see Sect. 25.2.8).

Pearl

Remember: the higher the magnification, the smaller the visual field and the greater the need to adjust the X-Y joystick to compensate for eye rotation. If the BIOM is used: the closer you are to the eye, the smaller an eye movement is enough to cause loss of the image.

30The height and the direction are determined by the type of microscope.

31With experience, the initial adjustment process, described above, takes into account the need for these upcoming readjustments.

32Obviously, the longer the surgery, the higher the need to readjust.