Technical data

26 Safety
G-30-1682-en OPMI® Lumera® T Issue 4.0
Printed on 02. 02. 2009
In the following, comments on these aspects are given and a description
of how Carl Zeiss, as a manufacturer, makes allowance for them in its
systems.
Illumination characteristics (spectral composition)
Studies on the exposure of the eye to light of varying spectral composition
date back to the early 1950s. These studies suggest that the potential
hazard of phototoxic injury to the patient's retina can be reduced by
blocking out the blue and ultraviolet light below a wavelength of 475 nm.
For protection of the retina, Carl Zeiss offers the blue barrier filter (retina
protection filter) as a standard feature of the OPMI Lumera surgical micro-
scopes. This reduces not only the exposure of the patient's eye to light,
but also that of the surgeon's.
An important point to note here, however, is that the use of filters will in-
evitably change the perceived color of the light. For this reason, the phy-
sician may initially have to get used to the changed appearance of the an-
atomical structures.
Illumination intensity
The majority of researchers suggest that the surgeon should use the
lowest light intensity required at the patient's eye to guarantee good
viewing during surgery.
Carl Zeiss has addressed this aspect by providing its systems with a de-
vice for continuously varying the brightness of the light source. This per-
mits the surgeon to optimally adapt the light intensity at the patient's eye
to the conditions existing in each case.
Angle of illumination
A number of publications
1)-4)
suggest that the microscope should be
tilted to reduce the exposure of the macula to direct illumination.
Carl Zeiss ophthalmic surgical microscopes are therefore equipped with
the following:
– Tilting mechanism for the microscope body
– Surrounding field illumination with brightness control
– Red reflex illumination (stereo coaxial illumination)