Page 4 - BPR

CUAJ – CUA Best Practice Report Bhojani et al
BPR: Laser eye safety

devices used in patients whereas the Rockwell Laser Industries database is restricted to
experimental AEs. Upon review of both databases, AEs were identified associated with various
laser wavelengths including 209, 140, 45 and 39 AEs attributed to the neodymium-doped yttrium
aluminum garnet (Nd:YAG), Ho:YAG, potassium titanyl phosphate (KTP) and the Indigo 830
nm diode lasers respectively. The majority of the AEs (86%) attributed to the Ho:YAG laser
were due to generator/fiber failures. Regarding AEs related to the medical operator, there were
only 11 reported with Ho:YAG laser. These injuries were minor skin burns that were related to
firing of the laser with a broken laser fiber. Although eye injuries were reported with the
Nd:YAG, KTP and the Indigo 830 nm diode lasers, no eye injuries associated with the Ho:YAG
laser have ever been reported during the 20 year history of the 2 databases.
A study by Villa et al, examined laser eye safety in an ex vivo porcine model[8]. This
study assessed the Ho:YAG laser at various and most commonly used urological laser settings
and at different distances from the ex vivo pig eye. Additionally, and importantly this study
examined the protection afforded by the use of laser safety goggles and standard eyeglasses in
preventing eye damage. 78 pig eyes were used for this study. The effect of the Ho:YAG laser on
eye damage was evaluated by directing the fiber towards the center of the pigs’ eyes at different
laser settings including: 0.5J at 20 Hz; 1J at 10Hz; 2J at 10 Hz. These laser settings were then
applied at 6 different distances (laser tip to eye surface): 0cm, 3cm, 5cm, 8cm, 10cm and 20cm.
The experiment was performed 3 times: once with laser safety goggles, once with standard
eyeglasses and once with no eye protection. It was determined that without eye protection, no
eye damage occurred at any setting when the tip of the laser fiber was at least 5 cm away from
the cornea. Additionally, no eye damage occurred at any distance in protected eyes. More
specifically, the use of standard eyeglasses was as protective as laser safety goggles at all laser
settings and at all distances.
To gauge current practice, a survey of the Endourological Society membership was
conducted by Paterson et al[10]. This study was based on a voluntary 24 question survey and
included 264 (14%) urologists from the Endourological Society. It was determined that 97% of
the urologists who responded to the survey routinely used the Ho:YAG laser but that only 40%
of respondents routinely wore laser safety goggles. Notably it was found that 70% of respondents
who used the laser safety goggles reported that the goggles impaired their vision while operating.
Finally, it was found that 19% of respondents had witnessed some form of injury associated with
the Ho:YAG laser, however, no eye injuries were witnessed by any individual at any institution
with or without the use of safety goggles.
An international twitter poll was conducted and included 322 respondents from around

the world. Among participants, only 19% routinely wore laser safety goggles. Similarly, a
survey of 7 Canadian academic and 23 US academic institutions demonstrated that only 3/30
surgeons wore laser safety goggles, and only 3/30 sites enforced usage. The majority of sites
(90%) had institutional policies that recommended the use of laser safety goggles.