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Lasers are used in a multitude of medical fields and specialties. However, they have been an integral part of the treatment and diagnostic capabilities in ophthalmology. Lasers can be classified into distinct categories in ophthalmology based on their mechanism of action, including thermal interaction, photodisruption, photochemical interaction, photoablation, and plasma-induced ablation. This activity reviews the principles of lasers in ophthalmology while discussing the different types of laser mechanisms and examines the complications of laser therapy and safety steps to effectively use lasers in ophthalmology by an interprofessional team. Objectives: Describe the mechanism of action of laser in ophthalmology. Review the different types of lasers based on the mechanism of action. Summarize diagnostic and therapeutic capabilities of lasers in ophthalmology. Discuss complications with lasers and safety measures when using lasers and the role of interprofessional collaboration in improving patient care both diagnostically and therapeutically. Access free multiple choice questions on this topic.

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.[1] 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.[2] 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.[1] 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.[1] 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.[1] 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.[3]

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.[1] 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.[1] 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.[3] 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).[4] 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.

Lasers are essential to ophthalmology treatment and diagnostics, but if used improperly can cause unnecessary injury. Understanding the use and mechanism of lasers is crucial for all team members associated with care. Lasers are best managed by an interprofessional team that includes an ophthalmologist trained in the specific use of that laser, nurses, and technicians, all contributing from their areas of expertise and engaging in open communication among team members, so that patient care is the top priority. Proper setup and safety precautions are important to ensuring patient and staff safety while maximizing outcomes and comfort.