L. Poirier et al., ENERGY FLUCTUATIONS IN AN EXCIMER-LASER DURING PHOTOREFRACTIVE KERATECTOMY, Journal of refractive and corneal surgery, 10(2), 1994, pp. 258-261
We performed an experiment with the MEL 60 excimer laser (Aesculap Med
itec Technology) to demonstrate the variations of energy of the laser
beam that could happen during a refractive surgical procedure. In orde
r to quantify such variations, we measured the whitening of a photogra
phic paper after a series of exposures to the laser beam with the X ri
te 400 B/W reflection densitometer. The energy fluctuations noted betw
een two series of pulses averaged 11.02% (minimum 0; maximum 46). Thes
e fluctuations tended to decrease progressively during the procedure.
The energy of the laser beam decreased with time. At the end of the ex
periment, the total loss of energy was 45.16%. These results suggest t
hat clinically meaningful energy variations could happen during the ph
otorefractive keratectomy and reduce refractive predictability.