Zeiss OPMI Lumera i, Instructions For Use Manual

Page: 18 / 184

Safety measures OPMI Lumera i
Version 8.0
Page 18 G-30-1720-en
Exposure time to light
According to some publications, the eye should not be exposed to the light
source longer than a few minutes. In all surgical cases, the retinal exposure time
to light depends on the type and duration of the procedure and possible case
complications. It is therefore recommended in ophthalmic surgery to keep the
light intensity as low as possible, or to use a device which prevents the light from
entering the patient’s pupil. It is also recommended to make sure that the
patient’s eye is not additionally exposed to the light of surrounding light sources.
This problem has been solved by ZEISS by the use of a swing-in retina protection
filter (blue barrier filter) that can be swung into the microscope’s illumination
beam path.
Brightness setting The brightness control scale of the ZEISS systems has a linear structure with
values ranging from 5% to 100%. The stipulations of standard DIN EN ISO
15004-2:2007 result in maximum radiation exposure times for the different
illumination configurations as specified in the table “Maximum radiation
exposure times” (see Page 20).
The maximum brightness of the lamps decreases in the course of time as
a result of normal wear.
Phototoxic risk factors The microscope light source—like any bright light source—may present a
potential hazard to the patient’s eye both in the form of immediately visible
thermal damage to the retina as well as phototoxic chemical reactions which
may lead to photoretinitis. The factors which play an important role in
determining the phototoxic risk are:
– Lamp brightness
– Spectral distribution of the light (UV and blue light are more dangerous
than longer wavelengths)
– Duration of direct exposure
– Pupil size
– Clarity of ocular media (infants and young children, for example, may be
at a higher risk)
– Condition of the eye: aphakic and pseudo-aphakic eyes with IOLs of
a material without UV/blue filter are at a higher risk.
– Previous exposure to bright light such as retinal photography, especially
within the last 24 hours