Laser Principles In Ophthalmology
| Autor: | Zhang AY; University of North Carolina- Chapel Hill, Kumar D; Wayne State University School of Medicine, Tripathy K; ASG Eye Hospital, BT Road, Kolkata, India |
|---|---|
| Jazyk: | angličtina |
| Zdroj: | 2022 Jan. |
| Abstrakt: | Since its development almost 60 years ago, lasers have made a huge impact on the medical field. The laser came about after the attempts by Charles Towns and Arthur Schawlow to produce a maser (microwave amplification by stimulated emission of radiation) that had higher frequency coherent radiation at wavelengths in the visible spectrum. Ophthalmology was the first medical specialty to utilize lasers, with the first report utilizing a ruby laser to treat ocular lesions almost a year after the invention of the laser, and still has the most laser procedures compared to any other specialty with the use of lasers permeating all subspecialties both diagnostically and therapeutically. Therefore, understanding the principles of lasers is integral to the foundational knowledge of ophthalmologists. In this review article, we will discuss the fundamentals of lasers, the different mechanisms of lasers in ophthalmology, their therapeutic and diagnostic uses in ophthalmology, and their complications. Laser is an acronym that stands for light amplification by stimulated emission of radiation. Electrons will emit a photon when they drop from higher energy to a lower energy level. Some of these higher energy states can be metastable, meaning they can maintain that high energy state for some time. When a photon of a specific frequency passes by this metastable electron, it may stimulate the electron to drop to the lower energy state and radiate a photon identical to the photon that stimulated the electron. Therefore, utilizing an active medium inside a resonator cavity with a fully reflective mirror on one end and a partially reflective mirror on the other can create a laser. By raising the energy levels of the medium with either an electrical or optical energy source, spontaneous decay causes the release of light, which will bounce back and forth in the cavity. The light, in turn, causes the emission of photons from the rest of the electrons that are all channeled into an intense beam that exits through the partially reflective mirror. The light is monochromatic and coherent since each particle has the same wavelength and phase. It is highly directional with a high energy density as it can be focused in a small area. Lasers can be defined by their medium, which can be gas (including argon and argon fluoride), liquid (including dye), solid (including neodymium: yttrium-aluminum-garnet), or semiconductor (diode). Due to the monochromatic nature of lasers, different mediums allow for lasers at specific wavelengths. Some examples are frequency-doubled neodymium: yttrium-aluminum-garnet (Nd: YAG) green laser at 532 nm, green argon lasers at 514 nm, krypton red lasers at 647 nm, and yellow semiconductor at 577 nm, diode laser at 810 nm, Nd: YAG laser at 1064 nm, and argon fluoride laser at 193 nm. (Copyright © 2022, StatPearls Publishing LLC.) |
| Databáze: | MEDLINE |
| Externí odkaz: |
|