PHOTOTOXIC RETINAL DAMAGE FROM OPERATING MICROSCOPE

Project: Research project

Description

Modern innovations in cataract extraction, viz. new extracapsular
techniques and the implantation of plastic intra-ocular lenses
(pseudophakos), have increased the risk of phototoxic retinal damage from
the illumination of the operating microscope. Clinically visible retinal
lesions from such light toxicity have recently been noted in patients. Experimental studies in pseudophakic rhesus monkeys at our institution have
shown that the threshold duration of exposure for production of a
clinically visible retinal lesion when the eye is held in a fixed position
is between 4.0 and 7.5 minutes with the microscope on the "high"
illumination setting (ca. 0.49 w/cm2 in the human eye). This phototoxic
retinal damage is caused primarily by the shorter wavelengths. The present
study is designed to determine the efficacy of the commercially available
Zeiss UV-430 filter in preventing such retinal damage. Rhesus monkeys will
undergo extracapsular lens extraction and pseudophakos implantation in both
eyes. One eye will be subjected to light exposure of a given duration with
the UV-430 filter in place, whereas the second eye will undergo an equal
duration of exposure with a neutral density filter that decreases overall
illumination to the same extent as the UV-430 filter (ca. 12%). The degree
to which the UV-430 filter protects the retina from the development of
clinically visible lesions will thus be determined. Light and electron
microscopy will be performed to study the lesions, comparing those produced
with and without the UV-430 filter, and to determine whether there is
histologic evidence of damage away from the clinically apparent lesion or
in eyes receiving exposure durations below the threshold for production of
a clinically apparent lesion.
StatusActive
Effective start/end date9/30/85 → …

Funding

  • National Institutes of Health

Fingerprint

Aminoglycosides
Anti-Bacterial Agents
Macaca mulatta
Lighting
Light
Crystalline Lens
Cataract Extraction
Lenses
Plastics
Retina

ASJC

  • Medicine(all)