Both the nurse and the circulator need to be familiar with the location and details of a list4 that must have been compiled earlier with vital information regarding:

•How to mix the intraocular (for injection or infusion) and local (fortified topical, periocular, subconjunctival) medications such as antibiotics and steroids.

•How to mix intraocular gases to achieve the required concentration.5

•The contact information (name and mobile phone number) for at least two representatives of all companies whose major equipment (vitrectomy machine, laser etc.) is used.6

Pearl

It is highly advisable to have a backup vitrectomy machine available, even if this is an older and less sophisticated one. It is solely for emergency purposes, in case the standard machine breaks down and cannot instantly be brought back to life.

16.2The Operating Table and the Surgeon’s Chair

16.2.1 The Operating Table

You should be able to adjust the following:

•Height.

•Inclination angle in either direction.

•The head part’s inclination angle (separately; see below, Sect. 16.6).

Ideally, a U-shaped wrist support7 is securely fixed to the table, and its height should also be adjustable (see Fig. 16.1).8 The table’s supporting mechanism must be far enough back from to leave space for the surgeon’s feet to have unhindered access to all three pedals.9

4This list must exist in a readily accessible electronic form plus as a poster on the OR wall. The electronic version should be on a computer that is not password protected.

5I once had a series of cases where the intraocular gas absorbed rapidly. For a while we were unable to identify the cause: the manufacturer changed the gas concentration in its bottles.

6This is especially critical if only a single machine is available, a rather risky situation.

7A VR surgeon uses his hands and fingers while operating, not his arms as general surgeons do.

8Some surgeons argue that they have so great dexterity and so little tremor (see Sect. 4.1) that they do not need wrist or lower-arm support. This may be so, but the question is why anyone would decline using a device that is inexpensive yet extremely useful since it increases the safety of intraocular manipulations.

9Microscope, vitrectomy machine, laser (see below, Sect. 16.3).

a

b

Fig. 16.1 The U-shaped wrist support on the operating table. (a) The “U” should be close enough to the patient’s head so that when the surgeon’s instruments are held in the vitreous cavity, the “U” is supporting the wrist and far enough so that the plastic bag collecting the waste fluid remains accessible (this means that the U’s shape and size need to be optimized to achieve these goals). The “U” must be padded to avoid hard counterpressure on the surgeon’s wrist. (b) The “U” must also be at the correct level as it relates to the eyeball. The most optimal height is for the top of the “U” to be just below the level of the lateral canthus: the one on this image is too low. Placing the “U” lower reduces its efficacy in providing support; if too high, it interferes with access to the eye. The latter is especially obvious when manipulations are needed in the anterior parts of the eye, such as hyphema removal or lensectomy

16.2.2 The Surgeon’s Chair

A well-designed chair should satisfy the following criteria (see Fig. 16.2):

•Wheels so that it can easily be rolled.

–Small “footprint”: the legs do not reach too far out, which would prevent the surgeon from moving close to the operating table.

•Locking mechanism against rolling and shaking.

–The surgeon himself should be able to activate/deactivate the break with a central pedal, and the break should work simultaneously on all wheels.

•Batteries to help unclog the OR floor.

•Electric, surgeon-operated height adjustment.

a

b

Fig. 16.2 The surgeon’s chair: the good, the bad, and the barely acceptable. (a) A chair that satisfies all demands [SurgiLine (UFSK-International OSYS GmbH, Heidelberg, Germany)]: it easily rolls but has a surgeon-activated break acting on all legs; the legs do not protrude outward; it has a battery to operate its height adjustment; the surgeon has easy access to the pedals for the chair’s up or down movement, yet these pedals are never in the way; the back support is ideally placed; the support for the lower arm is padded and completely mobile in all directions. (b) An acceptable compromise, except that the chair has no breaks, the height adjustment upward is easy for the surgeon to accomplish and to do so in small increments but the down movement is possible only by uncontrolled and large movements, and the armrest is not padded in the back (this becomes a significant issue during a long case or day). (c) A terrible chair, which is shaky, has no breaks, and the height adjustment requires manual work

•Easy-to-adjust arm support that can be moved in several dimensions (up-down; forward-backward; inward-outward both in whole and its distal end). The armrest should easily be secured.

•Comfortable padding on the armrests, which also provide support for the lower arm.

•Back support, which is adjustable in height and not positioned too far back.

16.3The Vitrectomy Machine,10 Its Footpedal, and the Arrangement of All the Pedals

•Different surgeons prefer different parameters (pump type, aspiration/flow values etc.). Yours should be stored in the machine under your own name.

– Always make sure that the display shows you as the surgeon.

The pedal can be programmed, on modern machines, to work in a linear, dual linear, or 3D mode.11

•When pressing down with the pedal, the aspiration/flow starts and gradually increases, and eventually cutting kicks in (linear).

–Many surgeons use a modified option: they activate the aspiration/flow function by pressing down with the pedal, and they turn the pedal sideways to add cutting as well.12

10The parameters are discussed under Sect. 12.1.

11Things are best when simplified; 3D mode is not the simplest option.

12This is, of course, an individual preference; as long as it is the surgeon’s conscious decision to use this setup, it is fine. The reason for this setup is, however, usually not a conscious decision but simply the “blind” following of the previous surgeon’s (mentor’s) “footsteps.” For me the turning of the foot leads to an unnatural, uncomfortable position.

•When pressing down with the pedal, both the aspiration/flow and the cutting start and gradually increase (dual linear).

•With pressing down with the pedal, both the cutting and aspiration/flow rates change, but in opposite directions (3D).

As indicated in Table 12.2, I prefer a set cut rate and liner aspiration/flow (linear).

Some vitrectomy machines allow more functions13 to be operated by the surgeon via the footpedal. He has to make an individual decision whether he prefers this option or choose instead the minimalistic one, asking the nurse/circulator to make the adjustment on the machine interface as needed.

•You have to work using two pedals.14 It is rational to place the microscope pedal under your dominant and the vitrectomy machine’s under your nondominant foot (see Fig. 16.3).15

Q&A

Q Why place the microscope pedal under the dominant foot?

A Because the foot operating the microscope will be much more active during PPV than the foot used to drive the PPV machine. It makes sense to employ the dominant (in 90% of the surgeons the right) foot the active one. This foot must control the X-Y joystick (see below), and the two focus and two zoom pedals. The nondominant foot basically controls the cutting/aspiration functions – with a single movement in my setup version. Both feet, of course, will have additional functions (such as the diathermy by the nondominant and the microscope’s light switch by the dominant foot), but even here the dominant foot will remain more active.

Unlike pretty much everything else in VR surgery, operating various pedal functions via the pedals should be completely automated.16 Switching the two pedals around requires “reprogramming” the surgeon’s brain.17

13Such as the regulation of the IOP.

14Actually, a third one should also be preplaced (“just in case”), the laser pedal, which is best placed in-between the two main pedals.

15Most surgeons arrange the pedals the other way around. When asked “why,” the common answer is a surprised stare first, followed by (see Sect. 3.2): “Because that’s how I found it [after the previous surgeon/s]” or “this is how it’s always been at our institution”.

16I.e., the surgeon must not be forced to stop and think about which of his feet is about to do what to achieve what kind of function on which equipment.

17This is why the initial setup in the OR is so crucial: have the pedals placed from your very first surgery the way you will always want them. If a surgeon operates in multiple ORs, the “customary” pedal arrangement may be different per OR. Some OR personnel prefer making the surgeon accept the local custom (for them it is easier than switching the pedals around). Insist on your own preference.