Measurement of the surface temperature of the cornea during ArF excimer laser ablation by thermal radiometry with a 15-nanosecond time response.
OBJECTIVE
The purpose of this work was to develop a temperature measurement system with a nanosecond time response to monitor the transient temperature of the corneal surface during laser refractive surgery.


METHODS
Thermal radiation from the surface of the porcine cornea during ArF excimer laser irradiation was measured using a photovoltaic HgCdTe detector with a response bandwidth of 150 MHz.


RESULTS
Maximum thermal radiation occurred at 31 +/- 4 nanoseconds, which was longer than the time response of the measurement system. The temperature derived from the detected signal reached over 100 degrees C at a fluence of 80 mJ/cm(2), which was the ablation threshold, and reached 240 degrees C at a fluence of 180 mJ/cm(2).


CONCLUSIONS
The present system of temperature measurement with a time response of 15.7 nanoseconds revealed that the transient surface temperature of the cornea during ablation is much higher than that previously reported.
Ishihara
Miya
M
Department of Medical Engineering, National Defense Medical College, Saitama, Japan. kobako@cc.ndmc.ac.jp
Arai
Tsunenori
T
Sato
Shunichi
S
Morimoto
Yuji
Y
Obara
Minoru
M
Kikuchi
Makoto
M
D000818:Animals; D003315:Cornea / Q000502:physiology* / Q000528:radiation effects; D066298:In Vitro Techniques; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D018903:Photorefractive Keratectomy; D011874:Radiometry; D013552:Swine; D013696:Temperature; D013821:Thermometers; D013997:Time Factors