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Scattered UV irradiation during VISX excimer laser keratorefractive surgery
Author(s) -
Hope R.J.,
Weber E.D.,
Bower K.S.,
Pasternak J.P.,
Sliney D.H.
Publication year - 2008
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.20627
Subject(s) - excimer laser , excimer , laser , irradiation , photorefractive keratectomy , cornea , materials science , optics , medicine , ophthalmology , physics , nuclear physics
Abstract Purpose To evaluate the potential occupational health hazards associated with scattered ultraviolet (UV) radiation during photorefractive keratectomy (PRK) using the VISX Star S3 excimer laser. Setting The Laser Vision Center, National Naval Medical Center, Bethesda, Maryland, USA. Methods Intraoperative radiometric measurements were made with the Ophir Power/Energy Meter (LaserStar Model PD‐10 with silicon detector) during PRK treatments as well as during required calibration procedures at a distance of 20.3 cm from the left cornea. These measurements were evaluated using a worst‐case scenario for exposure, and then compared with the American Conference of Governmental Industrial Hygeinists (ACGIH) Threshold Value Limits (TVL) to perform a risk/hazard analysis. Results During the PRK procedures, the highest measured value was 248.4 nJ/pulse. During the calibration procedures, the highest measured UV scattered radiation level was 149.6 nJ/pulse. The maximum treatment time was 52 seconds. Using a worst‐case scenario in which all treatments used the maximum power and time, the total energy per eye treated was 0.132 mJ/cm 2 and the total UV radiation at close range (80 cm from the treated eye) was 0.0085 mJ/cm 2 . With a workload of 20 patients, the total occupational exposure at 80 cm to actinic UV radiation in an 8‐hour period would be 0.425 mJ/cm 2 . Conclusions The scattered actinic UV laser radiation from the VISX Star S3 excimer laser did not exceed occupational exposure limits during a busy 8‐hour workday, provided that operating room personnel were at least 80 cm from the treated eye. While the use of protective eyewear is always prudent, this study demonstrates that the trace amounts of scattered laser emissions produced by this laser do not pose a serious health risk even without the use of protective eyewear. Lesers Surg. Med. 40:243–246, 2008. © 2008 Wiley‐Liss, Inc.