Phototoxic Injury To The Patient's Retina - Zeiss OPMI Lumera T Instructions For Use Manual

S88 / OPMI Lumera T

Phototoxic injury to the patient's retina

Version 8.0
G-30-1682-en
1)-5)
Several papers dealing with the problem of phototoxicity in ophthalmic
surgery have been published. A comprehensive review of these publications
reveals five aspects of particular concern:
– Illumination characteristics (spectral composition)
– Illumination intensity
– Angle of illumination
– Focus of the light source
– Exposure time to light
In the following, comments on these aspects are given and a description of
how ZEISS, as a manufacturer, makes allowance for them in its systems.
Illumination characteristics (spectral composition)
Studies on exposing the eye to light with varying spectral compositions have
been conducted since as early as the 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.
ZEISS offers the blue barrier filter (retina protection filter) for surgical
microscopes recommended for use in ophthalmic surgery. 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
inevitably change the perceived color of the light. For this reason, the surgeon
may initially have to get used to the changed appearance of the anatomical
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.
ZEISS has addressed this aspect by providing its systems with a device for
continuously varying the brightness of the light source. This permits the
surgeon to optimally adapt the light intensity at the patient's eye to the
conditions existing in each case.
Safety measures
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