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Laser Protection Options for Loupes

ErgoPractice News – October 2016
By Jin Chang PhD

Removable Laser Protection Provides Clinicians With Flexible Options for Laser Protection

The eye focuses visible and near-infrared light onto the retina and thus a direct laser beam can be focused intensely on the retina which may be up to 200,000 times higher than at the point where the laser beam enters the eye. This intense light can damage the retina by the thermal or photo-chemical effect. Eye protection from lasers is needed for both clinicians and patients.

Patients can use laser protection goggles that are readily available, but laser goggles are not practical when clinicians use loupes (Figure 1). So SurgiTel has developed various styles of removable laser protection filters that can be used with loupes. Before we review clinical laser protection options, let’s review the requirements of clinical laser protection.

When clinicians operate lasers, the lasers are located within a limited field of view of clinicians and thus laser protection requirements for the clinician are much less stringent than the requirements for the patients.

There are two laser protection options for loupe users:
  1. Laser protection filters between the user’s eyes and loupes.
  2. Laser protection filters in front of loupes.

Laser protection is achieved by materials that absorb or reflect laser lights.

SurgiTel’s requirements for laser protection filters designs are to block the transmission of the lasers lights for the best safety, to maximize the transmission of other visible lights for the best image, and to minimize the weight for the best comfort. To minimize the weight we should minimize the size of filters.

If eyes are to be protected over α(+/- 0.5α) degrees field of view, the radius (r) of filters will be given by (10 + D) x tan (0.5α degrees) where D is the distance from eye to the filter (Figure 2). If the distance D is 10mm and the filter should cover 30 degrees, the minimum radius of required filters is 6mm, assuming the center of eye rotation is 10mm behind the front surface of the eye.

SurgiTel has developed several types of laser protection filters:
  • Clip-in laser protection filters which are designed for Front-Lens-Mounted (FLM) loupes, but have been used for Through-The-Lens (TTL) loupes (Figure 3). These filters can be used with non-SurgiTel brand loupes.
  • Drop-in rimless laser filters which are designed for TTL loupes, but can be used with FLM loupes (Figure 4). These patent pending filters can be implemented with various frame types. This option is not available with other brand loupes yet.
  • Laser protection caps which are for both FLM and TTL loupes (Figure 5). For Galilean loupes, laser protection filter caps are attached in front of loupes. For prism loupes, laser protection filters are added into working distance caps. If users want to operate lasers without using loupes, frame lenses should be replaced with laser protection filters. This option is not available with other brand loupes.

Several companies offer dedicated laser loupes that have non-removable laser protection filters. Since these loupes will distort the color of objects, non-removable laser protection is not desirable to use for other procedures.

The use of removable laser protection filters by SurgiTel allows clinicians to use the same loupes for laser procedures as well as other procedures, without compromising on image quality for non-laser related procedures.

Most Common Questions About Laser Protection

Question #1: Do clinicians need laser protection side shields?
Comment: If there are several laser operators in the same room, everyone in the operating room may need laser protection side shields, but if only one clinician operates the laser, he or she will not need laser protection side shields.

Question #2: Is it safe to use only laser protection caps with loupes?
Comment: If the clinician may perform laser procedures without the use of loupes, carrier lenses should have laser protection, but the clinician performs laser procedures through loupes, laser protection caps for loupes are safe to use.

Question #3: Do assistants and patients need laser protection?
Comment: Laser protection goggles may be the best for patients and assistants can use laser protection glasses (side shields may not be necessary) or loupes with laser protection.

Do you need help deciding what type of laser protection is best for you? Contact your local representative, they can meet with you in your office and provide you with solutions!