Corneal damage effects induced by infrared optical parametric oscillator radiation at 3743 nm

Abstract

The main aim of this paper is to investigate the corneal damage effects induced by mid-infrared optical parametric oscillator (OPO) radiation. Experiments were performed to determine the corneal damage thresholds of New Zealand white rabbit at the wavelength of 3743[Formula: see text]nm for exposure durations of 0.1[Formula: see text]s, 1.0[Formula: see text]s and 10.0[Formula: see text]s. Through slit-lamp biomicroscope and histopathology, corneal injury characteristics were revealed. The damage thresholds were 3.73[Formula: see text]J/cm2, 7.91[Formula: see text]J/cm2 and 31.1[Formula: see text]J/cm2, respectively, for exposure durations of 0.1[Formula: see text]s, 1.0[Formula: see text]s and 10.0[Formula: see text]s. The damage data was correlated by an empirical equation: Radiant exposure at the [Formula: see text] duration,[Formula: see text] where the units of radiant exposure and exposure duration were J/cm2 and second. At near-threshold level, corneal injuries at 1 h post-exposure mainly involved the epithelium, and the epithelium damages repaired at 24-h post-exposure. There are sufficient safety margins between the damage thresholds and the maximum permitted exposures from current international laser safety standard IEC 60825-1.