Module 23: Ophthalmology (eye) and Laser Surgery PDF

MODULE 23: Ophthalmology (eye) and Laser Surgery Suggested Readings Alexander’s Care of the Patient in Surgery (2022) Chapter 18 Eyes; p. 226-236 Laser Tighe (2015) Instrumentation for the O...

MODULE 23: Ophthalmology (eye) and Laser Surgery Suggested Readings Alexander’s Care of the Patient in Surgery (2022) Chapter 18 Eyes; p. 226-236 Laser Tighe (2015) Instrumentation for the Operating Room Chapter 58 ORNAC Standards 2023 Learning Outcomes Describe the anatomy of the eye. Explain relevant surgical interventions and procedural considerations for ophthalmology surgery. Understand the importance of eye medication instillation. Distinguish between intra ocular surgery and extra ocular surgeries. Understand the protocol according to ORNAC for laser safely in the Perioperative setting. Anatomy Bony Orbit – Consists of seven bones, including: the maxilla, palatine, frontal, sphenoid, zygomatic, ethmoid, and lacrimal bones. The orbit contains the globe; orbital fat; extraoscular muscles, nerves, and blood vessels; and part of the lacrimal apparatus. Lacrimal Apparatus – The lacrimal glands produce tears and secretes them through a series of ducts onto the anterior ocular surface, thereby keeping the cornea moist and washing away debris. The tears then make their way to the lacrimal sac and finally pass into the nasolacrimal duct. Eyelid – The anterior eyelid contains the eyelid skin, ocular adnexa (eyelashes and glands), and subcutaneous tissue, lymphatics, and muscles. Conjunctiva – A thin, transparent mucous membrane divided into a palbebral portion (lining the inside of the eyelids) and a bulbar portion (lining the surface of the globe). Muscles – Extraocular muscles of the eyeball include the four recti (superior rectus, inferior rectus, medial rectus, and lateral rectus), and two oblique muscles (the superior and inferior oblique). The muscles work in pairs, with ocular movements generated by an increase in the tone of one set of muscles and a decrease in the tone of the antagonistic muscles. Globe (eyeball) – Supported in the orbital cavity on a cushion of fat and fascia. The globe is filled with two clear liquids: the acqueous humor (anterior to the lens) and the vitreous humous (behind the lens). Module 23: Eyes and Laser  Refractive Apparatus of the Eye (In order of importance) Cornea Lens Vitreous Humour Aqueous Humour Perioperative Nursing Considerations Nursing Assessment The ophthalmic patient range in age from premature infants with retinopathy of prematurity or congenital conditions to elderly patients whose condition result from the aging process. Most patients are admitted through an ambulatory admission area, and should be fully oriented to the physical surroundings. Constant description and reinforcement are important to visually impaired patients in the pre-operative and pre-induction phase. Patient Positioning - The surgical procedure determines the patient’s intraoperative position. Patients who are undergoing ophthalmology surgeries are commonly in supine position. Refer to the ORNAC Standards and the positioning performance checklist for appropriate practices. The patient position and the associated positioning devices may vary depending on the surgeon’s preferences and available institutional resources and policies. It is recommended that the perioperative nurse collaborates with the surgical team to ensure that the patient is positioned safely before, during, and after surgery. The perioperative nurse ensures that the patient return electrode pad is applied and the safety strap secured. Instrumentation and Counting Extra capsular instruments for retinal and muscle surgeries Module 23: Eyes and Laser  Intra capsular micro instruments for intra ocular surgery ie. Cataract surgery Eye scalpel ie. Beaver knife handle and blade Eye speculum (spring retractor) Left and right Corneal Scissors Vannas lens scissors Lacrimal probes Strabismus muscle hook Castroviejo needle drivers Ophthalmology procedures require a minor count. Initial Count (minor) → Closing Count (minor) → Final Count (minor) Eye Pharmacology – Numerous medications are used during ophthalmic surgeries. If pupils need to be dilated for the surgical procedures, instillation of eye drops may be indicated pre-operatively ie. Cataract extractions and other intra ocular surgeries. Drugs Purpose Dilating Drops Used to dilate pupils for intraocular surgery. Phenylephrine (Neo-synephrine) – Permits focusing Atropine – Inhibits focusing Constricting Drops / Miotics Used to constrict pupils during anterior segment surgery. Miochol (acetylcholine) Viscoelastics Used in intra ocular surgeries to lubricate and support; maintains separation between tissues Sodium hyaluronate (Healon, Amvisc, to protect the cornea. Provisc, Vitrax) Eye Irrigation Used to keep the cornea moist during surgery; also used as internal irrigant into Balanced Salt Solution (BSS) anterior and posterior segment. Epinephrine may be added to BSS to prevent bleeding. Hyperosmotic Agents Used in intraocular surgery to decrease intra- Module 23: Eyes and Laser  ocular pressure. Mannitol (osmitol) Injectable Anaesthetics May be used with varying concentrations of epinephrine, with a safe range between Lidocaine 1:50,000 to 1:200,000. Bupivacaine Mepivacaine Etidocaine Additives to Local Anesthetics Enzyme used to enhance the effect of the anesthetic. Hyaluronidase Antimetabolite Used topically to inhibit scar formation in glaucoma-filtering procedures; handle and 5-Fluorouracil (5-FU) discard in compliance with OSHA and Mitomycin facility policies. Be very careful with the above eye medications, as many names appear similar. Equipment Phacoemulsification Machine – Use ultrasound to break up the cataract, in conjunction with irrigation and aspiration, and bipolar electrosurgical handpieces. Posterior Vitrectomy Machine – Vitrectomy with cutter handpieces for removal of vitreous; extrusion for gentle aspiration near sensitive retina and macula. Cryotherapy Machine- Used to cause an inflammatory reaction in the retinal tissue that seals a break or tear, using nitrous oxide as the freezing agent. Lasers- Used for clearing an opacified posterior capsule after cataract surgery, for reshaping or creating a flap of the cornea, or for direct use inside the eye. Operating Microscope - Provides magnification and light (safe levels for the retina) for ophthalmic surgeries. Surgical Interventions Extra Ocular Surgeries Procedures performed on the extraocular muscles of the eyeball and two oblique muscles. Module 23: Eyes and Laser Strabismus Surgery – Repair of any ocular misalignment, as a result of poorly controlled neuromuscular eye movements. Common procedures in pediatric population, sometimes occurs in adults and/or are re-done in adulthood. Strabismus is subdivided into four categories: Esotropia - Inward turning of one or both eyes Exotopia - Outward turning of one or both eyes Hypertropia – One eye higher than the other Hypotropia – One eye lower than the other There are two methods for strabismus muscle repair: Recession (weakening procedure) – The muscle is cut and reattached at a point further back from the front of the eye. Resection (strengthening procedure) - Segment of muscle is removed and the shortened muscle is reattached to the eye. Enucleation- Removal of the entire eyeball, with the severing of its muscular attachments and optic nerve. This life-altering procedure is indicated for a blind, painful eye; intraocular tumors, and as a last resort after trauma. Other indication may include the retrieval of eye for transplantation after a patient has died. A round implant is inserted into the socket to replace the globe and provide support for a prosthetic eye. Removal of Chalazion – Surgery of the eyelid to remove chalazion (obstruction of the meibomian gland) causing secretions and manifests as a variably firm bump. Module 23: Eyes and Laser Repair of Entropion – Repair of the inverted eyelid. Repair of Extropian – Repair of the sagging and eversion of the lower lid. Common in older patients, caused by the relaxation of the orbicular muscle and tendons. Pterygium Excision – A pterygium is a fleshy, triangular encroachment of conjunctiva onto the peripheral area of the cornea. Retinal Surgery Vitreous fluid fills about 2/3 of the eye, helps keep the round shape of the eyeball, and is originally attached to the retina. The vitreous fluid decreases with age, and becomes stringy, and shadows can be cast onto the retina causing “floaters” (specks that float in the field of vision). If patients experience an increase in floaters, this could mean the retina has detached, torn, or broken. The repair is performed using lasers, by inserting gas bubbles into the vitreal body or surgically by doing a scleral buckling procedure. Laser Treatment in Diabetic Retinopathy Laser energy used to apply burns to peripheral retinal tissue to help neovascularization regress. Surgeons use the laser before excess damage occurs, electrocoagulating minute hypoxic areas to prevent the new vessels that are causing blurred vision and a potential for a detached retina from forming. Vitrectomy – Removal of all or part of the vitreous gel (body). Bleeding from damages or newly formed vessels may cause the vitreous to become opaque, which severely decreases vision. In addition, the surgeon is unable to visualize the retina and therefore treat the underlying pathologic condition before permanent damage can occur. Vitrectomy surgery is indicated to restore patient vision, and to allow the surgeon to treat the underlying condition. Pneumatic Retinopexy- Intraocular injection of a bubble of air or therapeutic gases provide pressure against retinal breaks, allowing the detached retina to push back onto choroids. Scleral Buckling – The return of the retina to its normal anatomic position from outside of the glove using a piece of silicone. The compression onto the choroid pushes down onto the retina, thereby resulting in reattachment. Intra Ocular Surgeries Cataract Surgery (Surgery on Lens) – Cataract extraction is the removal of the opaque lens from the interior of the eye and can be accomplished by several methods. Extra Capsular Cataract Extraction (ECCE) – The anterior portion of the capsule is first ruptured in a controlled manner and removed. The surgeon expresses the lens cortex and nucleus from the eye, leaving the posterior capsule behind using phacoemulsification Intra Capsular Cataract Extraction (ICCE) - Removal of the lens within its capsule with a cryoprobe (rare procedure performed with dislocated lens). Module 23: Eyes and Laser  Lasers Laser is an acronym that stands for “Light Amplification by Stimulated Emission of Radiation” and is defined as a device that convert some form of energy, usually electrical, into optical energy. Medical lasers use intensely focused light to treat or remove tissue, and can focus very specifically on tiny areas, thus being used for precise surgical work. Acronym Term Term Definition Process L Light Electromagnetic radiation of any wavelength A Amplification The process of making something larger and more powerful S Stimulated Stirred to action As photons become excited, they create more photons E Emission The process of Photons are released giving off or giving as laser energy out R Radiation The transmission of Photons of light are energy in produced and the form of waves emitted as a laser beam Characteristics of Laser Light Collimated - Laser energy is termed collimated because it can remain concentrated and easily focused over long distances. Collimation is possible because laser waves remain parallel to one other. The laser beam appears to stay as thin as a string or a pencil. When this beam is passed through a lens the light can be concentrated onto a tiny spot where the laser light will be concentrated. These are called “laser fibers” Coherent -This means that laser waves are organized and travel in phase or in the same direction. This is what gives the beam its power. Monochromatic - Laser light that has the same color or wavelength. Ordinary light consists of many different colours and many wave lengths. Module 23: Eyes and Laser Laser Power- The power or the energy of a laser beam is measured in Watts. A joule is the unit of measurement used to describe the total energy that was used during the procedure. Types of Lasers CO2 Laser Holmium/Yag Laser Green Light KTP Laser Modes of Operation (used for YAG/Holmium and Green Light) The output of a laser may be a continuous constant-amplitude output (known as CW) or continuous wave. With pulsed operation, higher peak powers can be achieved. Continuous wave operation- In the continuous wave mode of operation, the output of a laser is relatively constant with respect to time. The population inversion required for lasing is continually maintained by a steady pump source. Pulsed operation - The output of a laser varies with time, typically taking the form of alternating 'on' and 'off' periods. In many applications one aims to deposit as much energy as possible at a given place in as short time as possible. Lasers are labeled with a safety class number, which identifies how dangerous the laser is: Class I - Inherently safe ie. cd players. Class II - Safe during normal use ie. Laser pointers Class III - Up to 5 mW and involve a small risk of eye damage within the time of the blink reflex. Class IIIb/3B - Can cause immediate severe eye damage upon exposure. Usually, lasers up to 500 mW. The use of these lasers will require eye protection. Class IV/4 – The reflected or scattered light can cause eye or skin damage. Many industrial and scientific lasers are in this class ie. Lasers used in surgery. Strict safety guidelines by trained personnel must be followed when used to avoid harm. ORNAC Laser Safety Standards The Perioperative Use a Laser safety checklists Nurse Laser Direct all attention to the laser and the surgeon once the laser is Operator activated A second circulating registered nurse is required to attend to other requirements throughout procedure Documentation should be retained Environment Restrict traffic to authorized personnel Safety/ Controlled Place laser specific warning signs at all entrances Area Provide appropriate personal protective equipment ie. Laser specific eye protection for all staff prior to them entering the area Module 23: Eyes and Laser  where the laser is in use. Keep doors to the room closed Cover windows and spaces in the door frame with a laser-rated material for the appropriate wavelength being used Reduce reflective surfaces Fire extinguisher available Inform the laser safety officer of any breaches in protocol Remove signs when laser treatment is complete Eye Protection Laser eye wear protection shall: (Staff) Be permanently labelled with the wavelength and ocular density Have side shields Be inspected prior to use for damage/scratches Stored in individual cases or sleeves when not in use Be available for donning outside each entrance to the controlled area. Eye protection shall be worn by all healthcare team members in controlled area. Patient Healthcare team members shall protect the patient’s eyes during procedure – under general anesthesia awake. Fire Safety Healthcare team members shall be educated annually about the fire hazards associated with laser use, including anesthesia management during intubation that involve upper respiratory airway during laser procedures and others. The perioperative nurse shall be knowledgeable regarding ETT fire protocol. Instruments Only anodized, dull, or matte finished instruments shall be used near the laser site. Instruments that have been coated should be inspected regularly to ensure the integrity of the coating. Surgical Smoke Healthcare team members shall wear masks that are labelled “laser masks” during laser procedure. Healthcare team member shall wear an N95 mask when performing gynecological and/or urological procedures on patients with human papilloma virus. Module 23: Eyes and Laser