Opthalmic Surgery Flashcards
T/F: Alcohol and detergents are used on the cornea and conjunctiva
False
– alcohol and detergents damage the cornea and conjunctiva
How does the surgical prep of the eye differ from standard surgical procedures:
- delicate thin skinned eyelids
- cornea and conjunctiva are damaged by alcohol and detergents
- -bacterial flora present on ocular surfaces
- deep conjunctiva and 3rd eyelid harbors hairs and pathogens
What is placed in the eye before clipping
Lube ( KY jelly or ocular ointment) – prevents hair entering the conjunctival sac.
9 Steps for ocular surgical prep
- Place lube before clipping
- Clip periorbital hair and trim cilia
- clip eyelids gently if eyelid sx
- gently scrub periocular area with 1:50 (0.2%) iodine/ saline solution.
- clean conjunctiva and nictating membrane with cotton swab
- irrigate cornea with the same solution
- routine draping with animal placed in sternal (both eyes) or lateral (one eye) position
- Surgeon seated with armrests & Magnification.
What dilution of iodine/saline solution is used for ophthalmic sx:
1:50 (0.2%) iodine/ saline solution — VERY DILUTE
What ophthalmic instrument is used to place under the lower & upper lid to hold them open and allow examination of the cornea & conjunctival tissue.
Barraquer eyelid speculum
What ophthalmic instrument slips between the eyelid and the globe (protects the globe) and flattens out the eyelid to facilitate the procedure
Jaegar eyelid plate
What ophthalmic instrument acts as delicate forceps but can be used to grab conjunctival tissue
Bishop - Harmon Forceps
What ophthalmic instrument is used to hold small needle used on the eye. Regular needle drivers for other procedures would not secure the needle well enough due to how small the needle is for ophthalmic procedures
Derf needle holder
What ophthalmic instrument can be used to cut & resect skin of the eye. This instrument should only be used in ophthalmic procures because they need to be kept sharp & pointed.
Stevons Tenotomy Scissors
What are some methods in maintaining hemostasis of the eye:
- Direct pressure with cotton tip applicators
- Wedge shaped cellulose sponges
- 4 x 4 sponges
- . Hand held cautery
- Phenylephrine
- 1:10,000 epinephrine
What is a disadvantage of using 4x4 sponges or cotton tip applicators
They shed fibers that can irritate the cornea post-op
What tool can be used to control hemostasis without shedding fibers
Wedge shaped Cellulose sponges
What is the dilution of epinephrine used to control hemostasis in the eye:
1:10,000 epi
Eyelid lacerations are most often caused by:
Sharp trauma
Usually lacerations start ______ to the commissure of the eyelid then transverse ______
Usually lacerations start perpendicula to the commissure of the eyelid then transverse _parallel__
– lacerations can be full or partial thickness
What is important to look for when dealing with eyelid lacerations:
ALWAYS examine globe
– looking for any evidence of corneal ulceration which is very common to find with eyelid lacerations.
When repairing an eyelid laceration what is ESSENTIAL:
Meticulous anatomic apposition is essential for repairing eyelid lacerations.
– cosmetic & function
Meticulous anatomic apposition is essential for eyelid lacerations, for what 2 reasons:
- Cosmetic
- Function – failure to have proper occlusion of those commisures results in chronic problems with exposure to debri and dry eye (KCS)
Eyelid lacerations are closed in __ layers
2 layer closure
Describe the 2 layer closure for eyelid lacerations:
- Deep layer (muscle & fibrous tissue)
2. Skin layer (ensures apposition)
What patterns are used for eyelid lacerations for the 2 layer closure:
- -Deep layer = Simple continuous
- - Skin layer = Figure 8
In what direction is the bites placed for the first layer (deep layer) of an eyelid laceration closure:
Bites perpendicular to eyelid
- very important that bites are not so deep that they penetrate the conjunctival tissue.
- avoid conjunctiva
Which layer of the 2 layer closure for eyelid laceration ensure apposition:
2nd layer (skin layer) using the figure 8 pattern.
- helps to provide anatomical alignment by placing one of the throws right on top of that eyelid commissure where the lacerations occurred.
- it also helps bring the suture tags down lower (about 4-5 mm away from the commissure) so it is less likely your suture tags can come up and irritate the cornea.
What orientation is need when placing the knots for closing the skin layer for eyelid laceration repair:
Place knots away from cornea (use figure 8 pattern)
- start 4mm from eyelid
- exit 1 mm from margin
- 5/0 or 6/0 Vicroyl
What small, soft, braided suture is used in the figure 8 pattern to achieve apposition with the skin layer closure for eyelid laceration repair
5/0 or 6/0 Vicroyl
For repairing eyelid tumors, if the mass is _____ of eyelid margin then treat like a laceration (primary removal).
For repairing eyelid tumors, if the mass is _<1/3__ of eyelid margin then treat like a laceration (primary removal).
For repairing eyelid tumors, if the mass is >1/3 of eyelid margin then do a _____ resection of that tumor in 0.5 to 1 mm margins because they are not malignant
V resection: used for non-malignant tumors effecting >1/3 of the eyelid margin
What % of canine eyelid tumors are benign:
73% are benign
What is the most common canine eyelid tumor:
Meibomian Gland Adenoma
3 unique characteristics for Meibomian gland adenoma:
1.
2.
3.
3 unique characteristics for Meibomian gland adenoma:
- Exophytic
- Pendunculated
- Cauliflower
What does Exophytic mean:
Growing outward from the skin
What type of scissors are used for canine eyelid tumors:
Iris scissors
if the tumor is starting to approach <1/3 of the eyelid margin, what type of resection is used:
H resection
- make incision in the shape of a house
- allows less lid margin resection: preserves & helps to decrease the chance of having to do an eyelid reconstruction technique.
When dealing with eyelid tumors, which resection will take less lid margin.
H resection
If the tumor is >1/3 of the eyelid commissure, then what surgical technique is indicated:
Eyelid reconstruction
What are the 2 common malignant eyelid tumors that often result in eyelid reconstruction due to being <1/3 of eyelid margins.
- Adenocarcinoma
2. Melanoma
What can be done if there is an eyelid tumor that does not have the unique characteristics of a Meibomian gland Adenoma :
- FNA
- Punch biopsy
- FNA used for non characteristic M gland adenoma
- this will tell you if wide margins are indicated based on aspirate or biopsy results.
Name 4 Eyelid reconstruction procedures:
Name 4 eyelid reconstruction procedures:
- Single pedicle advancement flap
- Lip to lid flap
- Single pedicle advancement flap + conjunctival graft
- Semicircular Flap
Reconstructive technique used on both upper & lower eyelids when partial thickness is indicated:
Single pedicle advancement flap
SPA flap = partial thickness
Lip to lid = full thickness
T/F: it is important to cut the triangles BEFORE making the flap on the SPA flap reconstruction.
FALSE
– wait to cut the triangles until the flap is made to see how big the triangles need to be in order to relieve tension.
Reconstructive technique used for FULL thickness on the lower lateral side:
Lip to Lid flap
- creates a mucocutaneous flap from the oral cavity.
- take wide base, make bridging incision where eyelid defect would be, bring flap to the defect, suture closed the secondary defect that was created by the lip.
Reconstructive procedure that harvest the conjunctiva from the opposite eyelid of the defect:
Single pedicle advancement flap with conjunctival graft
– temporary tarsorrhaphy for 1-2 weeks until the conjunctival graft takes
Reconstructive technique used for LATERAL defects of both upper & lower lid by taking skin from the side of the face, pulling it over creating more skin to close the eyelid defect.
Semicircular Flap
- use triangle to create more skin to slide into the defect
Most common feline eyelid tumor:
SCC
- associated with light skin cats & sun exposure
- prognosis guarded
What is difficult with treatment of SCC in cats
Tumors in cats tend to be more aggressive
– harder to get wide enough margins to avoid recurrence.
T/F: Eyelid agenesis is more common in dogs than cats.
False – eyelid agenesis is more common in felines
T/F: Eyelid agenesis is most commonly associated with the MEDIAL side of the eye.
FALSE– upper lateral or lower central eyelid
** Important: it looks like it would be medial in all pictures but most common is LATERAL or lower CENTRAL eyelid
Most common area for Eyelid agenesis to occur:
Upper LATERAL
Small eyelid agenesis defects are treated _______
Large eyelid agenesis defects are treated _______
Small eyelid agenesis defects are treated = MEDICALLY ( Eye lubricants & Anti-inflammatories)
Large eyelid agenesis defects are treated = SURGICALLY ( Dziezye Milichamp Mucocutaneous Pedicle graft )