Transcript Ophthalmic Surgery

Ophthalmic Surgery
Outline
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Terminology
Anatomy
Pathology
Diagnostics/Testing
Anesthesia
Meds
Positioning/prepping/Draping
Equipment/Instrumentation/Supplies
Considerations
Procedures
Terms
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Abrasion-scrapping injury to the skin or a membrane
such as the cornea of the eye
Amblyopia-reduced or dimness of vision
Aqueous Humor-watery fluid that circulates thru
anterior and posterior eye chambers
Bony Orbit-rounded out socket in the skull or
cranium where the eyeball sits
Canthus-inner or outer corner where the eyelids meet
Terms
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Crystalline lens-part of the eye that in addition to the cornea, refracts light
rays and focuses them on the retina
Exophthalmia-abnormal protrusion of the eyeball from the bony orbit
(related to thyroid condition or orbital tumor)
Extra-ocular-outside globe of the eye
Extrinsic eye muscles-muscles that connect the eyeball to the orbital
cavity
Glaucoma-eye disease (↑ intraocular pressure = optic nerve atrophy and
blindness)
Globe- eyeball
Hyperopic-light rays come to focus behind the retina (farsightedness)
Myopia-light rays come to focus in front of the retina (nearsightedness)
Objects only seen if up close or near/can’t see farther away
Terms
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Intraocular-inside globe of the eye
Intrinsic eye muscle- muscle located inside the eyeball (iris
and ciliary body)
Iris- colored eye membrane; separates anterior and posterior
chambers; contracts and dilates to regulate light ray entrance
Limbus- edge of cornea where it unites with the sclera
Optic nerve- II cranial nerve responsible for vision
Sensory receptors- rods and cones in the retinal layer
(stimulated by light rays conduct nerve impulses to the optic
nerve)
Abbreviations
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OD oculus dexter = right eye
OS oculus sinister = left eye
OU oculus unitas = both eyes
Purpose of Eye Surgery
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Preserve or Restore Vision
Causes of Eye Defects
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Congenital
Injury
Disease
Anatomy of the Eye
Globe
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Eyeball
Compared to a sophisticated camera
All parts work together to produce a clear
image (vision)
Eyeball
1” diameter
 3 major layers:
1. Fibrous Tunic
 Outer layer/dense connective tissue
2. Vascular Tunic
3. Nervous Tunic
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Fibrous Tunic
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2 parts:
Sclera forms posterior portion of eyeball
Extrinsic eye muscles attach to this layer
Cornea forms anterior 1/3 eyeball
Cornea is transparent and avascular
Both cornea and sclera serve to protect the retina
Outer layer which covers and protects the exposed
portion of the eyeball and the inner eyelid is the
conjuctiva
Vascular Tunic
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3 parts:
Choroid
Provides nutrients/large number of blood vessels
Pigmented layer, thin and dark
Function to absorb light, reason see black in the pupil
Pierced by the optic nerve
Ciliary body
2 parts:
Ciliary muscle holds lens in place
Changes lens shape with accommodation (near and far focusing)
Iris
Radial/circular smooth muscle with hole in the center (pupil)
Controls size of pupil, therefore amount of light coming in and out
Nervous Tunic
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Innermost layer
Where retina ends anteriorly called ora serratus (scalloped
region
Contains nerves
3 parts:
Photoreceptor layer which consist of rods and cones
Bipolar layer photoreceptors synapse with bipolar neurons
Ganglia layer bipolar neurons feed into one ganglia neuron
this is the optic disc or blind spot an area where there are NO
photoreceptors
Rods and Cones
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Rods
Found in periphery of
center of back of eye
Not found in center of eye
Vision in dim or dark light
Allows vision of shape,
movement and shades of
gray
Overstimulation causes
pain (ex. dark to bright
light)
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Cones
Packed in one tiny area
called macula lutea (where
vision most acute/accurate)
Indention here is called the
fovea centralis
In the light, sharpness of
vision, shapes, movement,
color
Each cone has one of three
pigments: erythrolabe,
chlorolabe, cyanolabe
Colorblindness (FYI)
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Erythrolabe (red pigments)
Chlorolabe (green pigments)
Cyanolabe (blue pigments)
Depending on color coming in, determines which
receptors are stimulated
Colorblind means are lacking in one pigment,
usually erythrolabe
Total colorblindness means no pigments are present
Cavities of the Eye
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Anterior Cavity
Posterior Cavity
Separated by transparent structure called the
lens whose function is to bend and focus light
onto the macula lutea
Cataracts form with loss of the lens’
transparency
Anterior Cavity
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From the lens forward
Contains aqueous humor which is watery
Formed in the ciliary body
Provides nutrients, helps bend light
Drained by canal of Schlemm where the cornea
meets the sclera
Too much causes increased IOP (intraoccular
pressure), untreated causes glaucoma/seen in chronic
unmanaged hypertensive patients
Anterior Cavity
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Contains 2 chambers:
Anterior chamber anterior to iris
Posterior chamber posterior to iris
Both contain aqueous humor
Posterior Cavity
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From lens back/posterior to lens
Contains thick gelatinous clear fluid called
vitreous humor
Vitreous humor keeps the eyeball from
collapsing, holds the retina in place, and helps
to bend light
Body produces all it needs when you’re born
You cannot produce anymore
Orbit
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May be called the bony orbit = socket that
eyeball sits in
Seven bones form the orbit:
Frontal, sphenoid, ethmoid, superior
maxillary, malar (zygomatic), lacrimal, and
palate (see figure 16-1, AST pg 577)
Eye Muscles
1. Extrinsic Eye Muscles
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Muscles that connect the eyeball
to the orbit and allow for
movement of the eye
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Six total extrinsic muscles:
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Superior rectus– movement up
and temporal
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Inferior rectus- movement down
and temporal
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Medial rectus- straight nasal
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Lateral rectus- straight temporal
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Superior oblique- movement
down and nasal
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Inferior oblique- movement up
and nasal
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Intrinsic Eye Muscles
Muscles located inside the
eyeball
Includes:
Iris
Ciliary body
Lacrimal System
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Lacrimal Gland- secretes tears and keeps cornea
moist
Located in upper eyelid at outer angle
Excretory Ducts
Carries fluid to surface
Empty into lacrimal sac which becomes
the nasolacrimal duct leading to the nasal cavity
Nerves and Blood Supply
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2nd cranial nerve (optic nerve) vision
3rd cranial nerve (oculomotor) 1° motor nerve medial rectus, inferior
rectus, superior rectus, and inferior oblique muscles
4th cranial nerve (trochlear) superior oblique
6th cranial nerve (abducens) lateral rectus
Formula to remember LR6(SO4)3
3 stands for the rest of the extraocular muscles
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Ophthalmic artery supplies orbit and globe, branches off the carotid artery
Branches of ophthalmic artery supply globe, muscles, and eyelids
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Alexander’s p. 664
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Physiology of Vision
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Light comes into eye
Light passes thru cornea and pupil
Iris regulates amount of light entering
Light goes through lens (light is refracted)
Light then to the retina
Light rays stimulate rods and cones (sensory receptors of
retina)
Impulses conveyed to the optic nerve
Optic nerve to the brain
In the brain, the visual area of the cerebral cortex in the
occipital lobe of the cerebrum interprets vision
Physiology of Accommodation (Focus)
http://www.youtube.com/watch?v=15P8q35vNH
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Pathology
Cataracts
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Crystalline lens has become opaque
Is a condition, not a disease
Prevents light passage
Vision is impaired gradually
Can cause blindness, untreated
Causes: aging, certain drugs, chemical
exposure, sunlight exposure, disease,
congenital
Retinal Detachment
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Small
Develop around a
retinal tear
Vitreous pulling away
from retina, fluid
becomes stringy (see
spots and flashes of
light)
Corrected by laser or
cryotherapy
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Large
With tear, vitreous gets
under tear and under retina
separating it from the
choroid
Vision is lost where retina
detaches
See veil or shadow from
one side, above or below
Completely detached, all
vision is lost in that eye
Vitreous Hemorrhage
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With retinal tear, blood vessels torn and
vitreous hemorrhage occurs
Vitrectomy must be performed to determine if
a retinal tear has occurred
(PVR)
Proliferative Vitreoretinopathy
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Occurs 5-10% post-scleral buckle (procedure
performed to repair detached retina)
Scarring pulls on retina creating redetachment
Epiretinal Membrane
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Scarring over the macula (area of retina where
vision most accurate) results in a cloudy
appearance
Membrane is removed surgically
Corneal Pathology
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Clouding of the cornea results in diminished
vision
Caused by:
Eye injury
Corneal infection
Disease
Any eye surgery
Corrected by corneal transplant (keratoplasty)
Chalazion
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Lump in the inner or outer eyelid surface
Inflammatory reaction to debris trapped in oilsecreting gland of the eyelid
Eyelid can become red and swollen
Hot compress produces cheese-like discharge
Dacryocystitis
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Inflammation of the lacrimal sac
Caused by obstruction of the nasolacrimal duct
Area below eye beside nose is red and swollen
Sensitive
May have a mucous discharge at inner canthus
Surgery entails opening blockage and treating
infection
Strabismus
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Misalignment of the eyes
“Cross-eyes” (esotropia)
“Wall eyes” (exotropia)
Due to restrictive or
paralytic eye muscles
Are six eye muscles
Corrected by Recession
and Resection
Pterygium
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Fibrous wedge shaped benign
conjunctival growth that often
extends out into the cornea
Treatment usually with steroidal
anti-inflammatories
If extend into cornea, vision is
impaired requiring surgical
intervention
Pterygium repair may involve
removal of part of the conjunctiva
Entropian
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Inversion (turning in
on itself) of the lower
eyelid
Ectropion
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Eversion (turning out)
of the lower eyelid
Diagnostics & Testing
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Visual exam
Vision impairment complaints
Eye pain, irritation, burning, drainage, redness
Asymmetry
Ophthalmoscope exam by physician
History of HTN, diabetes, allergies,
medications patient is on
Tonometer - measures intraocular pressure
Anesthesia
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General (children, selected patients)
Retrobulbar Block
Both
Local
Idea to keep eye completely still and lower
intraocular pressure
Medications
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Label immediately
Most are colorless and you must label to avoid any confusion with identity
Classifications:
Anesthetics
Antibiotics
Anti-inflammatories
Irrigants
Miotics
Mydriatics/cycloplegics
Vasoconstrictors
Dyes
Viscoelastic agents
Enzymes
Anesthetics
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Injectable
Xylocaine (Lidocaine)
Bupivicaine (Marcaine, Sensorcaine)
Topical
Cocaine (4%)
Tetracaine (Pontocaine)
Proparacaine (Alcaine, Ophthaine)
Used to produce absence of sensation
May be local or topical
Antibiotics
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Garamycin
Neosporin
Bacitracin
Erythromycin (Ilotycin)
Gantrisin
Gentamycin
Sulfacetamide
Tobramycin
Prevent or treat infection
May be drops or ointment
Injected or Topical
Anti-inflammatories
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Steroids
Dexamethasone
(Decadron, Maxidex)
Betamethasone
(Celestone)
Prednisone (PredForte,
PredMild)
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NSAIDS
Ketorolac (Acular)
Diclofenac (Voltaren)
Flurbiprofen (Ocufen)
Suprofen (Profenal)
Reduce inflammation
and prevent edema
Injected or Topical
Irrigants
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BSS balanced salt solution
Tis-U-Sol balanced salt solution
Lacrilube
Duratears
Lactated Ringer’s solution
Irrigate anterior chamber
Keep cornea and eye tissue moist
Soak and rinse intra-ocular lens
Miotics
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Acetylcholine chloride (Miochol)
Carbachol (Miostat)
Pilocarpine hydrochloride (Pilocar)
Contract pupil
Reduce intra-ocular pressure
Prevent loss of vitreous humor in cataract surgery,
maintaining lens placement
Topical Drops
Mydriatics/Cycloplegics
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Mydriatics
Neo-synephrine (Phenylephrine)
Atropine sulfate (Atropisol)
Dilation of the pupil (mydriasis)by paralyzing iris muscle
Cycloplegics
Cyclopentolate (Cyclogyl)
Tropicamide (Mydriacyl)
Dilation of pupil by paralysis of the iris muscle and paralysis of the
accommodation mechanism
After administration, compress lacrimal sac 2-3 minutes to avoid systemic
absorption
These drugs increase IOP (intraocular pressure) and should NOT be given to
patients with glaucoma
Vasoconstrictors
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Epinephrine (Adrenalin)
Cocaine
Prolongs duration of anesthetic
Decreases bleeding
Injected or topical
Most commonly see epi mixed with lidocaine as one
solution (ex. Marcaine with epi)
Dyes
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Fluorescein sodium (Flu-glo)
Rose bengal
Lissamine green
Indocyanine green (IC green)
Marks or colors tissue
May be used to diagnose abnormalities (corneal
abrasions) or locate foreign bodies
May be used to see flow of aqueous humor or
demonstrate the lacrimal system’s function
Viscoelastic Agents
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Sodium Hyaluronate (Healon, Amvisc-Plus,
Viscoat)
Hydroxypropyl methylcellulose (Occucoat)
Thick jelly like consistency
Injected into anterior chamber during cataract
surgery to maintain chamber expansion and prevent
surrounding tissue damage
May be used as vitreous substitute
May be used for tamponade (compression)
Enzymes
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Protein that act as catalyst (speed up chemical
reactions)
Alpha-Cymar and Zolyse two most commonly used
Increases absorption and dispersal of the anesthetic
agent
Wydase (hyaluronidase) was phased out in 2001 due
to quality assurance issues
Wydase was replaced with Vitrase a hyaluronidase
product that comes from sheep testicles
Positioning
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Supine
Non-operative side arm on an arm board
Operative side tucked
Pillow or headrest (may use donut) under
head
Pillow under knees
Heel protectors
Prep
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Eyebrows never shaved unless surgeon requests (do
not grow back completely)
Lashes trimmed per surgeon orders with fine scissors
coated in petroleum to catch lashes
Eyelids and peri-orbital areas cleaned with nonstaining antiseptic
May flush conjunctiva with BSS or benzalkonium
chloride
Eyes should be shut during pre may protect with
sterile plastic sheet
Draping
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Likely have entire face exposed even if surgery is
unilateral for comparison
Head drape or towel and medium sheet place under
patient’s head, bring around on either side crisscrossing at hairline or forehead, fasten with clip
Towels around face
Fenestrated eye drape to expose operative eye
Bottom/body sheet for rest of patient
Sterile plastic drapes placed over towels or cloth
drapes to prevent lint
Equipment
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Microscope
Diathermy probe/apparatus
Cryotherapy unit/probe
Endocoagulator (bipolar or wet-field)
Occutome
Argon laser
Endoilluminator
Bipolar unit
Check all equipment prior to use
Instruments
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Specialty surgeon microscopic eye trays
See pgs. 584-594 in your AST text for a list of
instrumentation
See Rutherford as well
Supplies
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Eye pack
Basin set
Disposable eye drape/sterile plastic adhesive drape
Microscope drape
Pre-cut cellulose sticks (weck cells)
Suture 4-0 to 12-0 gauged monofilament nonabsorbable and absorbable
(see Table 16-2 in AST text)
Needles: (see Table 16-1 in AST text)
Round bodied
Round bodied with cutting tip
Reverse cutting
Spatulated
Beaver blades
Eye patch for dressing
Special Considerations
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Lint free towels/drapes
Will function as ST and STFA
Imperative to be able to anticipate surgeon needs due
to most patients are awake and quiet is preferable
Handle sutures carefully and as little as possible
Take care with delicate instrumentation
Familiarize self with use of all ophthalmic
equipment before attempting to use
Meticulously REMOVE powder from gloves to
prevent corneal abrasions!
Complications
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Infection
Hemorrhage
Tissue rejection with corneal transplant
Scarring
Glaucoma
Retina swelling
Retinal detachment
Cataract formation
Swelling
Vision impairment
Ophthalmic Procedures
 Strabismus Correction
 Scleral Buckle
 Enucleation
 Evisceration
 Keratoplasty
 Cataract Extraction
 Vitrectomy
 Pterygium Surgery
Strabismus Correction
 Strabismus is a visual
disorder where the eyes
are misaligned and point
in different directions.
Scleral Buckle
 Scleral buckling surgery
is the most common way
to treat retinal
detachment.
Enucleation
 Enucleation is the
surgical removal of the
eyeball that leaves the
eye muscles and
remaining orbital
contents intact.
Evisceration
 The surgical removal of
the contents of the eye,
leaving the white part of
the eye and the eye
muscles intact.
 This is done to relieve a
blind and painful eye due
to injury and/or infection
when the eye is
completely destroyed
and blind.
Keratoplasty
 a surgical procedure in
which part or all of a
damaged or diseased
cornea is replaced by
healthy corneal tissue
from a donor cornea;
transplant to treat
Keratoconus (abnormal
cone-shaped protrusion
of the cornea of the eye)
Cataract Extraction
 Cataract surgery is the
removal of the natural
lens of the eye (also
called "crystalline lens")
that has developed an
opacification, which is
referred to as a cataract.
Vitrectomy
 Vitrectomy is a surgery to
remove some or all of the
vitreous humor from the eye.
 Anterior vitrectomy entails
removing small portions of the
vitreous from the front structures
of the eye - often because these
are tangled in an intraocular lens
or other structures.
 Pars plana vitrectomy is a
general term for a group of
operations accomplished in the
deeper part of the eye, all of
which involve removing some or
all of the vitreous - the eye's clear
internal jelly.
Pterygium Surgery (pronounced tur-IJ-ee-um)
 conjunctival removal
 A pterygium growing
across the cornea can
cause distortion,
resulting in impaired
vision. In advanced
cases, a pterygium can
cover the pupil, causing
visual loss
Summary
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Terminology
Anatomy
Pathology
Diagnostics & Testing
Anesthesia
Meds
Positioning/prepping/Draping
Equipment/Instrumentation/Supplies
Considerations
Procedures