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What Ever Happened to Medical Surveillance?

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Did you know there was a time when eye exams were suggested every three years for users of Class 3B or Class 4 lasers? The rules around so-called medical surveillance began to change in 2007, when the American National Standards Institute’s (ANSI) laser standards ceased to require baseline eye examinations for users of these laser classes. What happened to cause this change? To answer, let us first trace the role and purpose of the baseline eye exam.

As lasers became an increasingly widespread tool in research and industry, several questions arose about visual safety in the workplace. Would negative effects result from chronic exposure to laser pulses? Would visual conditions such as color blindness put users at greater risk? These questions may seem antiquated and even foolish today. But back in 1973, when ANSI published its first laser standard (Z136.1 Safe Use of Lasers) at the request of the U.S. Department of Labor, these were real unknowns.

There was a time when safety concerns around the use of Class 3B or Class 4 lasers prompted recommendations that users receive baseline eye exams and subsequent checkups every three years. The rules around so-called medical surveillance have changed. Courtesy of

There was a time when safety concerns around the use of Class 3B or Class 4 lasers prompted recommendations that users receive baseline eye exams and subsequent checkups every three years. The rules around so-called medical surveillance have changed. Courtesy of,

The 1973 edition of the Z136.1 standard proposed medical surveillance requirements — for example, an eye exam — for Class 4 users in the following conditions:

   1. Prior to participation in laser work.

   2. On discharge from the laser environment.

   3. Every three years while work with lasers continued.

   4. Immediately after suspected laser eye or skin damage.

   5. In conjunction with a complete skin examination.

The standard is just that: a standard. But while ANSI describes it as a voluntary guidance document, the U.S. Occupational Safety and Health Administration (OSHA) reserves the option to cite enterprises that do not meet defined guidelines for a safe work environment. For those of us operating in the real world of physics, such standards take on a level of regulatory authority, due to the fact that OSHA allows the use of consensus standards [1910.1 (a) & (b)] where it does not have specific rules already in place on a hazard. OSHA has taken the position that adhering to Z136.1 or related Z136 standards is proof that one is properly addressing laser safety.

If an enterprise is found not to be properly addressing safety, it can be cited under section 5(a)(1) of the Occupational Safety and Health Act, OSHA’s General Duty Clause (GDC). The section requires an employer to furnish to its employees a place of employment that is free from recognized hazards that are causing or are likely to cause death or serious physical harm to employees.

To cite an organization under the GDC, OSHA must prove that:

   1. The employer failed to keep the workplace free of a hazard to which its employees were exposed.

   2. The hazard was recognized as a hazard.

   3. The hazard was causing or was likely to cause death or serious physical harm.

It should be clear that working with Class 3B and Class 4 lasers easily meets all of these thresholds.

When the 1980 edition of Z136.1 was published, the document changed the recommendation for eye exams to apply only for the first and fourth conditions: prior to working with select laser classes and after eye or skin damage. This language remained for all subsequent editions, until 2007, when the “shall” do a baseline exam changed to a “should.” Each following edition (starting in 2012, and pending in 2021) has trimmed down its proposed requirements for medical surveillance to apply only in cases where an injury is suspected.

Astute readers of standards may notice that the medical surveillance appendix contains guidance on eye exams. Please note that all the appendixes, excluding Appendix A, in Z136.1 are informational only and not considered part of the standard’s requirements.

As for retinal injuries, the injuries we most care about, an eye exam can easily distinguish a new wound from an old one. Further, unless the injury is within the macula/fovea region, there will be no permanent impact on vision. I am not aware of any case in which an employee claimed eye injury from a laser source post-employment. If there were such a case, I would be interested in following the outcome.

What about employer liability? The Z136.1 standard has never considered the concept of legal liability of an employer to fall within the realm of laser safety. The Technical Subcommittee on Laser Bioeffects for Z136 has determined that baseline eye exams have not demonstrated sufficient value to continue the “shall” requirement. Some baseline examinations have found underlying eye disease but, just as with liability protection, this discovery is not the core function of the exam.

Are companies and institutions dropping eye exams as a result? Some are. Others fear such an action would be interpreted as showing less concern about safety. This impression can be overcome by educating staff about laser safety — or by blaming the standard for the change.

At the 1999 International Laser Safety Conference, John Marshall, a renowned scientist and pioneer of laser eye surgery, gave a keynote address titled “Do Eye Examinations Have a Role in Laser Safety Programs?” His conclusion, based on a review of the previous 40 years, was that they should be discontinued. In summary, baseline eye exams have long outlived their usefulness and, if you are still conducting them, you can stop — especially if you are using lasers outside the retinal hazard region between 400 and 1400 nm.

Meet the author

Ken Barat, operator of Laser Safety Solutions, is a certified laser safety officer (CLSO); email: [email protected].

Photonics Spectra
May 2021
columnsLasers In UselasersLaser Safety

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