Exam 1 - Ophthalmic Procedures Flashcards
what are the ideal magnification factors for ophthalmic procedures?
2.5-4.5x with a built in light source
comfortable working distance = relaxed arms with straight & upright neck/head
what are the advantages & disadvantages of using an optivisor for magnification?
advantages - commonly used & inexpensive
disadvantages - uncomfortable working distance & lacks a light source
what are the pros & cons of using absorbable suture for ophthalmic procedures?
pros - don’t need to remove sutures
cons - tissue reaction/inflammation, multifilament > monofilament
what size suture should be used for eyelid procedures?
4-0 to 6-0
what are the pros & cons of using monofilament suture for ophthalmic procedures?
pros - less tissue reaction
cons - greater memory/stiffness, so greater potential for corneal injury
what is this instrument?
derf needle driver - grasp needle around middle/tip of drivers, palm the needle holder, approach tissue with 90 degree angle, roll the wrist
‘right angle, roll, repeat’
what is this? why is it important?
bishop harmon 1x2 forceps - most commonly used
what is this instrument? what is it used for?
tenotomy scissors - general use scissor for sharp & blunt dissection around the eye
what is this instrument? what is it used for?
general operating scissor - cutting suture
what are the 2 reasons lid plates are used?
used to stretch & stabilize the eyelid
enables precise incisions
all of these can be used as what?
lid plates
what kind of scalpel grip is used for ophthalmic procedures?
pencil grip - #15 blade with bard-parker handle
when would you use the eyelid speculum?
cherry eye repair
conjunctival biopsy or injection
what ophthalmic procedure might you use a sterilized rubber band for?
tarsorrhaphies - used to distribute suture pressure across the eyelid
what ophthalmic procedure might you use a chalazion clamp for?
everts & localizes pathology - ectopic cilia
hemostasis - isolates certain tissues to help them stop bleeding, used for debulking & cryotherapy
what positioning should be utilized for ophthalmic procedures for the surgeon & patient?
surgeon - sitting with arm/wrist support
patient - cutting surface parallel to the table
what should be done for patient prep for ophthalmic procedures?
lubricate ocular surface - prevent corneal ulceration from exposure
lubricate scissors for hair collection
trim eyelashes & periocular hair
safely decontaminate the periocular skin/ocular surface - use a solution or betadine because scrub has alcohol in it
how should betadine be diluted?
1:50 with saline - weak tea appearance
alternating rounds of betadine & saline (eyelids - betadine soaked gauze & saline soaked gauze 3 times, ocular surface - betadine flush & eyewash flush 3 times)
what prep solutions should be avoided for ophthalmic procedures?
alcohol, chlorohexidine, & betadine scrub
what is the importance of the haired-nonhaired junction of the skin for ophthalmic procedures?
- figure 8 suture begins here!
- incisions for hotz-celsus entropion repair & transpalpebral enucleation begin here
- eyelid tacking
what is the surgical relevance of the ‘grey line’ for ophthalmic procedures?
- distichia arise from meibomian gland orifices
- common location for eyelid tumors
- figure 8 suture engages this landmark
- tarsorrhaphy engages this landmark
what is this?
eyelid margin - grey line, requires magnification
what is the tarsal plate of the eye?
fibrocartilaginous layer that gives structural support to the eyelids & meibomian glands about 5-10mm wide that is lined with palpebral conjunctiva
what are all of these pictures of?
tarsal plate
what is the surgical relevance of the tarsal plate?
- ectopic cilia arise here, most often 12 o’clock
- holding layer for eyelid margin lacerations/defects
- meibomian gland tumors often extend into the tarsal plate
what is the holding layer for eyelid margin lacerations/defects?
tarsal plate
identify the anatomic structures labeled 1-4
- skin - haired non-haired junction
- eyelid margin/meibomian glands
- tarsal plate & palpebral conjunctiva
- loose/unsupported palpebral conjunctiva
what is the permanent surgical correction for entropion?
holtz-celsus
what is a temporary procedure used for entropion repair?
tacking using horizontal or vertical mattress sutures
what is the holtz-celsus entropion repair?
elliptical skin excision made & vertical mattress sutures are placed to surgically correct entropion
what is entropion?
eyelid inverts in
what is the rule of thumb for entropion repair?
while the patient is anesthetized, manipulate the eyelid by pulling/rolling out the entropion to what would be a normal position - measure by estimation or callipers
what is the goal in temporary tacking in entropion repair?
over correct! get the eye comfortable to heal the ulcer
what is the preferred suture type for tacking sutures in an entropion repair?
4-0 to 5-0 nylon
where is the first bite located for tacking in an entropion repair?
1-2mm outside of the haired non-haired junction
the distance between the first & second bite in tacking for an entropion repair should be what?
the distance required to restore normal eyelid position
where is your first incision made in a holtz-celsus repair? what about the second? how is the distance between the 2 incisions determined?
parallel to lid margin, 1-2mm outside of the haired non-haired junction
2nd incision is curved
distance between the two is the distance required to restore normal eyelid positioning
how is closure performed in a holtz-celsus entropion correction?
simple interrupted bisecting pattern to prevent dog eyes - start in the middle
T/F: in holtz-celsus entropion repair, surgical trauma induces chemosis, causing a mild ectropion which is expected & should resolve by first recheck in 10-14 days
true
canine eyelid tumors most often demonstrate _____ characteristics & feline eyelid tumors most often demonstrate ______ characteristics
benign
malignant
after removing an eyelid mass, what should you do?
submit it for histopathology
what are your 2 options for eyelid mass removal?
excision & debulk/cryo
what are the pros & cons of using excision for eyelid mass removal?
pros - minor anatomic limitations, more aggressive & more often curative relative to debulk/cryo
cons - requires surgical confidence to safely close the eyelid margin & need to protect the incision site/sutures
what are the pros & cons of using debulk/cryo therapy for eyelid mass removal?
pros - less aggressive but often curative & less post-op concern
cons - requires cryotherapy machine
if the size of an eyelid mass is approaching 1/3 the size of the lid margin, what are your concerns?
can’t take more than 1/3 without causing functional disturbances - consider rotational graft or referral
if an eyelid mass is causing irritation to the ocular surface, what should you do?
remove or debulk/cryo
what happens if you have an eyelid mass that involves the nasolacrimal ducts or canthus?
consider referral
why should you avoid wedge incisions in removing eyelid masses?
they take unnecessary lid margins - instead make a house shape to preserve a healthy margin
what are the 4 key concepts in closing eyelid margin defects?
- limited debridement
- closure must be perfect - figure 8 suture pattern at the margin
- avoid full thickness suture bites
- tarsus is the holding layer
T/F: improper closure of an eyelid margin can cause more complications than they eyelid mass
true - excisions & lacerations carry the same concerns
what is the purpose of a tarsorrhaphy?
temporary treatment for lagophthalmos
what is lagophthalmos?
incomplete closure of eyelids
what are 3 causes of lagophthalmos?
cn v dysfunction, cn vii, & proptosis
what are the steps for correcting proptosis?
- lubricate & protect (e-collar)
- deep sedation/general anesthesia
- monitoring equipment
- reduce globe & monitor for vagal reflex - eyelid stay sutures & blunt counter pressure
- clip & clean eyelids
- perform tarsorrhaphy - usually 2 horizontal mattress sutures
- prescribe oral antibiotics, topical antibiotic, & topical atropine
- recheck every 7-10 days
- remove sutures when orbital symmetry returns (2-4 weeks)
what is a common mistake made using cryoepilation for distichia?
improper probe placement directly onto the eyelid margin - ineffective
how is cryoepilation done for distichia?
probe placed on tarsal plate, hold until ice ball reaches meibomian glands then wait until probe thaws & repeat for 2 freeze-thaw cycles then pluck the distichia (hair should easily slide out if follicle was destroyed)
what are some common complications of cryoepilation for distichia?
marked eyelid swelling & depigmentation (most often temporary)
