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With the advent of excimer laser use in ophthalmic applications, it is important to recognize that there are additional safeguards needed in treatment facilities that may not be essential in research and industrial applications.1"3 Excimer lasers are used now in research for laser angioplasty and in ophthalmology for performing either linear or large-area corneal ablation. The objectives of such ablations are phototherapeutic keratectomy (PTK) - ie, removal of pathologic corneal surface opacifications, surface irregularities, and band keratopathies - and for photorefractive keratectomy (PRK) to correct refractive errors.
As will be shown, the principal safety concern with an ArF excimer laser is the handling and containment of toxic gases associated with the operation of the laser. Commercial medical laser systems have generally been designed with an extra level of gas safety features because of the intended use in a hospital or clinical environment. This level of safety should considerably exceed the norm for excimer laser safety in an industrial or research setting. Current ophthalmic excimer lasers employ a pulsed argon-fluoride (ArF) laser which poses potential hazards; however, current commercial systems have redundant safety features to minimize or virtually eliminate the chance of a serious accident. Operating room personnel would not be exposed to potentially hazardous laser radiation emitted from this system during normal use. Principal precautions relate to the control of potentially hazardous airborne contaminants associated with any excimer laser.
LASER SAFETY STANDARDS
User Laser Safety Standards
In the USA, voluntary consensus standards of the American National Standards Institute (ANSI) apply to laser use.4-5 OSHA and JCAH will generally consult standard ANSI Z- 136.3 Safe Use of Lasers in the Health Care Environment, if a question arises relating to laser safety.5 The Threshold Limit Values (TLVs) for airborne contaminants and laser radiation published by the American Conference of Governmental Industrial Hygienists6 may also be consulted.
Manufacturer's Laser Safety Regulations
In the USA, the Center for Devices and Radiological Health (CDRH) of the Food and Drug Administration (FDA) regulates laser manufacturers.7 Federal regulation 2 ICFR 1040 requires manufacturers to meet certain performance standards, ie, to install certain system safety features, such as a protective housing and a key-switch master control.
Laser Safety Classification
Both of the above standards as well as other national and international standards...