Zeiss OPMI Lumera i, Instructions For Use Manual

Page: 19 / 184

Version 8.0
G-30-1720-en
Page 19
OPMI Lumera i Safety measures
During cataract procedures, factors such as lenticular material, instruments
such as the phaco handpiece, and movement of the eye provide interruption
of the exposure This is expected to significantly lengthen the time before
photoretinitis might be expected to occur.
Effects of microscope
illumination
A prospective study
7)
of the effects of microscope illumination during surgery
did not reveal any phototoxic retinal injuries for procedure times of up to
30 minutes if the calculated maximum recommended exposure time was
150 seconds. However, it was also found that at the same brightness setting,
phototoxic retinal injury could be expected after approximately 100 min.
Stereo Coaxial Illumination The Stereo Coaxial Illumination (SCI) of this system has been designed to
provide a bright red reflex using only very small quantities of light in the center
of the surgical field. The peripheral illumination causes higher exposure of the
retina, but, depending on the position of the eye, usually not the macula
directly. For cataract procedures, ZEISS recommends adjusting the surrounding
field illumination to be somewhat darker than the central red reflex spot.
Not only does this setting minimize phototoxic risk but it also reduces glare
from the patient’s sclera.
Other recommendations for minimizing the phototoxic risk are:
• Always use the lowest brightness setting possible.
• Use the retina protective filter (blue barrier filter) to block the blue spectrum
of light. The retina protection filter increases the recommended exposure
times by a factor of 3.
• When working on the exterior eye, use the retina protection device to
prevent light from entering the pupil, especially when the pupil is dilated
(see Page 38).
• Always switch off the microscope illumination during pauses in surgery.
Either move the surgical microscope to the standby position for this
purpose or cover the patient’s eyes.
Maximum radiation exposure The following table is intended to provide the surgeon with a guideline in
determining the potential hazard. The data has been calculated for the worst
case scenario:
– direct radiation exposure,
– uninterrupted radiation exposure, e.g., no surgical instruments in the eye,
– aphakic eye,