Lasers ophthalmology and effects of some laser wavelengths on ocular tissues

Abstract

The proportion of the electromagnetic spectrum concerned with ophthalmologyranges from the ultraviolet portion through the visible wavelengths and intothe near and far infrared areas. In addition to the tunable dye laser, which can producewavelengths from the ultraviolet into the infrared portion of the spectrum, othrelasers have provided ophthalmologists with fixed wavelength emissions that havebecome enormously important in the treatment of various diseases.The interaction of a specific laser emlSSlOn or wavelength with variousocular tissues can be divided into six distinctly different tissue changes associatedwith: 1- Photocoagulation therapy, 2- Photodynamic therapy, 3- Photovaporizationtherapy, 4- Photodisruption therapy, 5- Photoablative decomposition therapy,6- Phototherapy.Nd-Y AG laser permits the `noninvasive` incision of intraocular structures.Results of this study support the hypothesis that a one stage filtering procedurecan be performed solely with the Nd-YAG laser. But, because of the required highenergy levels, complications or distant effects of the YAG shock wave may occur ina living human eye.