Fuller Chapter 26 - Ophthalmic Surgery

ectropion

Drooping of the lower eyelid. Creating an overflow of tears and exposes the conjunctiva, which becomes dry and irritated. Outwardly turned eyelid. Often associated with age but also with congenital effects or paralysis (bells palsy)

Diathermy

Low-power cautery used to mark the sclera over an area of retinal detachment.

Goal of Ophthalmic Surgery

Restore vision lost as a result of disease, injury, or congenital defect.

Ophthalmic ultrasonography

Used to measure the density of the eye tissue and detect abnormalities. Two types are an A-scan and a B-scan

Glaucoma

a group of diseases characterized by increased intraocular pressure. Sustained pressure on the optic nerve and other structures may result in ischemia and blindness.

the _______ lies directly behind the iris in the anterior chamber. It is a clear biconvex disc contained in a transparent capsule.

lens

The __________ is a distinct area of acute vision that lies near the optic nerve. The center of this structure is called the fovea centralis .

macula

plicated

folded inwardly

Three tissue layers of the cornea

epithelium (superficial, the stroma, and the endothelium.

congenital glaucoma

fluid drainage system is abnormal at birth. The infants eye sistends, and corneal haziness occurs. Symptoms include light sensitivity and excessive tearing. Surgery is indicated to prevent blindness.

The optic nerve enters the posterior cavity through the _______________.

optic foramen.

The ____________ enters the posterior cavity through the optic foramen.

optic nerve

Iris

pigmented membrane composed mainly of muscle tissue that surrounds the pupil. Actions of the muscle fiber cause the pupil to close/open - exclude/admit light to inner eye.

Most ophthalmic surgery is performed using a regional anesthetic with monitored ________. This means the patient is awake and able to hear sounds in the surgical environment.

sedation

BSS

balanced salt solution

The macula is a distinct area of acute vision that lies near the optic nerve. The center of this structure is called the __________________.

fovea centralis

Enucleation is performed for

intraocular malignancy, penetrating ocular wound, painful blind eye, eye that is blind and painless but disfigured (can get an artificial prosthesis)

IOP

intraocular pressure

Dacrocystitis

inflammation of the lacrimal sac caused by an obstruction of the nasolacrimal duct. Causing pain, swelling, and redness at the site of the medial canthus.

Lateral rectus resection

A portion of the muscle is excised and the severed end is reattached to the original site of insertion. This limits the drift of the eye.

Rhegmatogenous detachment

A tear in the retina

entropion

Abnormal inversion of the lower eyelid. Inwardly turned eyelid, which causes the eyelashes to rub on the cornea. Occurs in older indivuduals caused by weakness and imbalance.

anterior vitrectomy

Performed to remove the vitreous from the anterior chamber. happens when the posterior chamber is ruptured.

How does the eye sponge work

Sponge is never used on cornea, sponge absorbs fluid by wicking. This is done by holding the tip of the sponge in direct contact with the fluid and allowing the sponge to absorb it.

Muscle recession

Surgery in which the eye muscle is moved back to release the globe. Performed to correct the deviation of the eye caused by strabismus.

Lamellar Keratoplasty

The anterior chamber is not entered, and one half to two thirds of the cornea is transplanted.

dacryocystorhinostomy

The creation of a permanent opening in the tear duct for the drainage of tears. Performed using an open or endoscopic technique.

Penetrating keratoplasty

The full thickness of the cornea is removed and replaced with donor tissue. The anterior chamber is entered.

Medial rectus recession

The muscle is detached from its insertion , moved posteriorly and reattached. This releases the eye and allows it to move farther in a lateral position.

Primary open-angle glaucoma (POAG)

This is a chronic disease occuring in both eyes. It develops in the middle years or later. In this condition, the outflow of aqueous humor is obstructed in the trabecular meshwork, which can be caused by different factors.

Normal tension glaucoma

This is a subtype of open angle glaucoma in which IOP is normal. There is retinal damage and visual field loss with migraine and optic disc hemorrhage.

Primary angle-closure glaucoma (PACG)

This type of glaucoma accounts for 30% of all cases. Higher incidence in women. Sudden rise of IOP is caused by total blockage or obstruction of the aqueous humor at the root of the iris. Considered a medical emergency b/c blindness may result if the blockage is not relieved.

Retrobulbar block

an injection of anesthetic behind the eye used for some eye surgeries

The _______________ is divided into two spaces, the anterior chamber and the posterior chamber.

anterior cavity

Each juncture of the eyelids is called a _________________

canthus

Eye sponges are made of lint-free ________ or similar material.

cellulose

The highly vascular pigmented ____________ layer lies directly beneath the sclera. The primary function of the _____________ is the prevent the reflection of light within the eyeball.

choroid

Cornea

clear tissue layer overlying the front of the eyeball

Tears produced as a result of emotion have a different ____________ than those arising from irritation and pain.

composition

Ophthalmic ultrasonography: A-scan ultrasound

depicts tissue density as amplitude on two axes. The output is represented in waveform, resembling an electrocardiogram. High density tissue produces an amplified wave.

trabeculectomy will fail if a ____________ does not form in the first few postoperative days

flat bleb

The ____________ have separate cavities, each of which contains functional structures.

globe

Shifting the patient immediately after surgery may result in _______________________

increased IOP and eye injury.

The lacrimal ducts extend from the inner canthus to the lacrimal sac. The opening of each duct is called the __________________

lacrimal punctum

Two types of corneal transplantation

lamellar (partial penetration) and penetrating (full-thickness)

The ______ is the only passageway between the anterior and posterior chambers.

pupil

The space or interval between the upper and lower lids is called the ________________________--

palpebral fissure

Filtering Procedures (Trabeculectomy)

performed to create a channel from which aqueous humor may drain from the anterior chamber. Procedure performed for glaucoma.

Sclera buckling procedure for detached retina

performed when the sensory layer of the retina becomes separated from the pigment epithelial layer.

refraction is a test for visual acuity, performed using a ______________.

phoropter

Eye Prosthesis/Artificial Eye: conformer

placed over the sphere and covers the surface

The __________________ lies at the back of the eyeball and contains a gel called vitreous.

posterior cavity

The optic nerve enters the ______________ through the optic foramen.

posterior cavity

The anterior chamber lies in front of the iris, whereas the _________________ lies behind the iris but in front of (anterior to) the lens.

posterior chamber

Ophthalmic ultrasonography: B-scan ultrasound

produces an image of the target tissue that shows a series of spots, the brightness which corresponds to tissue density. As tissue density increases, the image appears darker. For example, vitreous appears very dark or black on ultrasound.

Light enters the eye through the cornea and it is ____________: this allows images to be focused on the retina

refracted (bent)

Exenteration

removal of the entire contents of the orbit

Repair of an ectropion lower lid

restore eyelid to normal position. A wedge of tissue is removed from the lower tarsal plate, and the excess tissue is excised to tighten the lid.

In full-thickness keratoplasty a _____________________ are required to prepare and transplant the donor tissue.

separate table and mayo setup

___________ separate bones come together to form the orbit.

seven

The suspensory ligaments change ______ of the lens to bend light that passes through the lens.

shape

The lens is held in place by

suspensory ligaments

lacrimal apparatus produces

tears

Repair of an entropion lower lid

the goal is to restore the eye to correct anatomical position by resection. Retractor muscles are exposed and plicated with sutures

The anterior cavity of the eye is divided into _____chambers: The anterior and posterior chambers

two

each eye has four rectus muscle: the superior, inferior, lateral, and medial. Each eye also has _____ oblique muscles: the superior and inferior.

two

fluorscein angiography

used extensively in the diagnosis and evaluation of retinal and choroid diseases. It delineates areas of abnormality and is essential for planning laser treatment of vascular disease. In this test, fluorescein dye is injected intravenously. When the dye reaches the retina and choroid, the vessels and the epithelium are clearly delineated and images are recorded.

ophthalmoscope

used to examine the eyes, handheld instrument that magnifies the focal point, allowing the examiner to evaluate the fundus and other internal eye structures.

tonometer

used to measure intraocular pressure

Ophthalmic surgery position

usually supine with patients head in a doughnut.

The posterior cavity lies at the back of the eyeball and contains a gel called ______________.

vitreous

Posterior cavity contains _____________

vitreous body

Eye Prosthesis/Artificial Eye: Sphere

what the implant is called

suspensory ligaments are also called ____________ which are attached to the capsule and ciliary body.

zonules

Beam splitter

A device that transmits an image from the primary ocular to an observer tube, producing an is identical picture.

Spatula needle

A flat-tipped suture needle commonly used in ophthalmic surgery.

Zoom lens

A lens that increases or decreases magnification and is operated by the foot pedal.

coaxial illuminators

A light source (usually fiberoptic) transmitted through the lens or body of the microscope. It illuminates the area in the field of view of the objective lens.

Broad-field viewing lens

A low-power magnifying glass attached to the front of the oculars that produces an overview of the field.

X-Y attachment

A mechanism that allows the scope to move precisely along a horizontal plane.

Refraction

A phenomenon of physics in which light rays are bent as they pass through a transparent medium that is denser than air. In the eye, refraction occurs as light enters the front of the eye and passes through the cornea, lens, aqueous humor, and vitreous.

Accomodation

A process in which the lens continually changes shape to maintain the focus of an image on the retina

phacoemulsification

A process whereby high-frequency sound waves are used to emulsify tissue, such as a cataract.

Assistant binoculars

A separate optical body with a nonmotorized, hand controlled zoom.

Cyrotherapy

A technique in which a cold probe is used to freeze tissue, such as the sclera, ciliary body (for glaucoma), or retinal layers, after detachment

Pterygium

A triangular membrane that arises from the medial canthus; the tissue may extend over the cornea, causing blindness.

ciliary body

An extension of the choroid layer . Located at the periphery of the anterior choroid. Composed of smooth muscle to which suspensory ligaments are attached.

Chalazion

An inflammatory benign growth that originates in the sebaceous gland or the eyelid. Surgery usually performed in the outpatient setting or clinicians office.

Cataract

Clouding of vision caused by a disease in which the crystalline lens of the eye, its capsule, or both become opaque. This prevents light from focusing on the retina, resulting in visual distortion.

aqueous humor

Fills the anterior chamber, a clear fluid produced by the ciliary epithelium

Bridle Suture

In ophthalmic surgery, a temporary traction suture placed through the sclera used to pull the globe laterally for exposure of the posterolateral surface. It is called a bridle suture because of its resemblance to the reins of a horse's bridle.

Strabismus

Inability to coordinate the extraocular muscles, which prevents binocular vision.

Retina

Innermost layer of the posterior globe. Photoreceptive layer of the eye. It receives and transmits images to the brain via the optic nerve.

Paraxial illuminators

One or more light tubes that contain incandescent bulbs and focusing lenses. Light is focused to coincide with the working distance of the scope.

Keratoplasty

Surgery of the cornea. The term penetrating keratoplasty refers to corneal transplantation.

Evisceration

Surgical removal of the contents of the eyeball, with the sclera left intact.

Enucleation

Surgical removal of the globe and accessory attachments.

Muscle resection

Surgical shortening of an eye muscle to pull the globe into the correct position. Performed to correct the deviation of the eye caused by strabismus.

Ocular (eyepiece)

The component of the microscope that magnifies the field of view.

Objective lens

The lens that establishes the working distance and produces the greatest magnification

Illumination system

The lighting system of the microscope.

Magnifying power

The magnification specification of a lens

Focal point

The point where light rays converge after passing through a lens.

slit lamp

Used to examine the anterior chamber of the eye.

Skin prep for ophthalmic surgery is performed _________ the patient has been anesthetized

after

The ____________________ lies in front of the iris, whereas the posterior chamber lies behind the iris but in front of (anterior to) the lens.

anterior chamber

Anterior cavity contains

aqueous humor

Orbital cavity is also called ____________

bony orbit

When preparing micro-surgical instruments, the scrub should check for ___________ (rough or jagged spots on sharp instruments)

burrs

The standard approved eye prep antiseptic is __________________________ (5% or as directed by surgeon)

dilute povidone-iodine

each eye has _____ rectus muscle: the superior, inferior, lateral, and medial. Each eye also has two oblique muscles: the superior and inferior.

four

A reassuring environment is extra important in ophthalmic surgery because the patient is awake and increased anxiety can result in _________________________________

increased hemorrhage and intraocular pressure

An ________________________________ is used to examine the retina and other structures with a wider focal point

indirect binocular ophthalmoscope

The eyelids protect the eye from

injury and light

During cataract surgery, the initial incision is made in the ______ where the two tissues meet

limbus

Tears are composed of

many chemicals, including proteins, mucus, sodium chloride, glucose, and enzymes capable of breaking down the cell membrane of bacteria.

compound microscope

microscope that uses two or more lenses in a single unit

The optic nerve exits the globe in an area of dense neurons called the ____________. This has no photoreceptors.

optic disc

_________________________ located along the lid margin and in the lacrimal caruncle secrete waxy oil that seals the eyelids when they are closed

sebaceous glands

____ muscles attach the sclera to the bony orbit and move the eyeball around various axes

six

The eyelids are composed of fibrous connective tissue referred to as the ______________ covered with skin

tarsal plate

The pupil allows aqueous humor to pass between the two chambers through a space between _________________________

the lens and the iris

Sclera

thick, white, fibrous tissue that encloses about three fourths of the eyeball. It is the external supporting layer of the eyeball.

palpebral conjunctiva

thin, transparent mucous membrane that lines each eyelid and reflects onto the globe, where it is called bulbar conjunctiva.

Cornea is made up of _________ tissue layers

three