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150 Chapter 6

6.1.1 Intraocular surgery

Intraocular surgical procedures, or vitreoretinal surgery, involves instruments smaller than 20-
gauge (Fig. 6.1), to provide additional benefits, such as reducing trauma and removing the
need for sutures [1 4], but at the cost of losing rigidity in the instruments [5]. The vitrector
may be replaced with a different tissue manipulator depending on the surgery’s needs.

There are typically two types of light sources in use for vitreoretinal surgery: light pipes
and chandeliers.

6.1.1.1 Light pipes
A light pipe is usually pointed toward the posterior pole instead of at the instrument tip,
supplying an illumination angle of 50 100 degrees. This reduces glare from the fiber optic
tip and generally provides better illumination [6]. Because of its rigidity, it is used in
conjunction with the vitrector to “roll” the eye, to provide the surgeon with a better viewing
angle. However, this rigid nature can limit the illumination options of the surgeon. As a
result, surgeons have implemented solutions to overcome this, such as manually bending
the light pipe [7]. One drawback of the bent shape is a reduction in the light intensity
provided by the light pipe due to light scattering. However, with advances in light source

Figure 6.1
A typical vitreoretinal surgery with instruments of vitrector, light pipe, and infusion pipe.