Ophtalmology 1 Flashcards
What can you do to make eye surgeyr easier for yourself?
- Theatre setup
- Able to turn lights off
- Chair
- Easy access to instruments
- Magnification
- Patient positioning
Describe ophtalmology table?
Thin -> combibnation of microscope, FFD, patient, cushion & table less than distance b/w surgeon’s knees and eyes
hat magnification of Loupes?
- Range is 2.5 – 6x
- Ideal for corneal procedures is
about >4x - Can use 3-3.5x for eyelids and
occasional corneal suturing
Microscope magnification?
- Range is 4-24x
- A good microscope will have a
variable range so it can be
adjusted to suit during surgery.
Patient positioning for ophtalmic sx?
Eye in a parallel plane
At a comfortable working distance
Able to sit with legs under table
Vacuum cushions
What are these ?
- Stevens tenotomy scissors for ST aroudn glove
- Eyelid speculum
What are these?
- nettleship diltors (enlarging nasolacrimal ducts)
- Macallan or Jaeger lid plate -> stabilising hen cutting
What are these?
- Chalazion clamp -> isolating section of eyelid and reducing BF
- Cilia forceps -> removal fo distichia
What are these?
- Mosquito artery forceps
- Derf needle holders 4/0, 6/0
What are these?
- Curved corneal scissors
- Toothed tying forceps -> conjuncitvea and eyelids
What are these?
- Fine toothed tying forceps -> corneal & suture handling
- Fine needle holders without a catch
What are these?
- Standard scalpel blade holder
- Beaver blade handle
What are these?
- Callipers
- Lens vectis -> removal fo lens during intracapsular extraction
Describe drapes ?
> Adhesive patch
Use warmth of hands to heat
adhesive and improve adherence
when placed
Pocket to catch fluids
If this gets very full it can distort
the surgical site due to its weight.
Swabs ?
Ophthalmic spears
PVA
Doesn’t shed material
Cellulose
Can leave cellulose material
behind
What knives/ blades would you use?
Describe non-absorbable sutures material?
- E.g. polypropylene
- Less reaction
- Requires removal
- Lasts a very long time
Describe Absorbable sutures?
- E.g. polyglactin 910
- Can induce reactions
- Multifilament
- Suture breakdown - Loss of strength in a shorter time frame
- Can be left to resorb
Needle choice?
What should you use for eyelids?
- 4/0-6/0 Polyglactin 910
- 5/0 Nylon
What to use for Conjunctiva
- 6/0-8/0 Polyglactin 910
What to use for Cornea ?
9/0 Polyglactin 910
How to do corneal suturing?
Corneal closure ?
- Simple interrupted -> slow effective
- Continuous -> 9/0 Vicryl, Spatulated needle , Double continous torque anti-torque pattern
What can cause suture failure?
- Bite is
- Too shallow
- Too narrow
- Has too much tension
- Knot is
- Not tied correctly
- Cut too short
- Tissue is
- Still undergoing collagen lysis (melt)
- Under too much tension
- Suture is
- Incorrectly chosen
Functions of eyelids?
- Protection
- Light, external trauma
- Distribution of tear film
- Production of lipid component of tear film
- Removal of excess tears and foreign material
- Communication
Entropion Surgery?
HO TO CLOSE entropion repair?
Other eyelid surgeries?
Sliding Plasties
- Replacement of eyeldi deficits
- When primary closure is not possible
e.g. hen mass is larger than 1/3-1/2 of eyelid length
Describe Temporary Tarsorrhaphy
> > Used post globe
proptosis
* Supports the cornea
* Stops re-prolapse while tissue swelling reduces
* Cannot visualise the eye
* Sutures can rub on cornea if placed slightly incorrectly.
* Use nylon sutures and plastic tubing
Indications for eye removal?
● Loss of vision
● Pain
● Life threatening disease
Signs of chronic ocular pain?
“Old age”
◦ Lethargy
◦ Weight Loss
◦ Poor coat condition
◦ Often not recognised by the owner until after resolution
Life threatening dx?
- Neoplasia -> intraocular (melanoma) or extraocular - (meningioma)
- Diagnostics for systemci dx -> Lymphoma, Fungal dx
Common causes fo enucleation?
● Glaucoma
● Neoplasia
● Globe rupture
What alternatives to enucleation?
● Glaucoma
◦ Intrascleral prosthesis (ISP)
◦ Chemical ablation
◦ Intravitreal gentamicin
● Neoplasia
◦ None
● Blunt trauma
◦ ISP
Surgical prep for enucleation?
◦ Clip 2 inches around eye including eyelashes
◦ Prep in standard fashion as for general surgery
◦ Flush out fornices including behind third eyelid
How do we perform our retrobulbar anaesthesia?
◦ 2 inch curved 19G needle
◦ 5mls of lignocaine
◦ +/- adrenaline
◦ Advance through dorsolateral conjunctiva under rim of orbit
What are the advantages of a Transconjunctival approach?
● Quick
● Reduced blood loss
● Reduced tissue loss
◦ Less dead space
◦ Less orbit sinking
◦ Quicker recovery
Disadvantages of transconjunctival approach?
● Extraocular spread of neoplasia
● Infected eye not covered with
conjunctiva
Step 1 of Enuc?
Latheral canthotomy
Step 2?
Conjunctival incision
Step 3?
EXTRAOCUALR MUSCLES
Step 4?
EXTRAOCULAR MUSCLES
Step 5?
OPTIC NERVE
STEP 6?
Ho to assess for haemorrhage?
STEP 7?
Remove third eyelid
Step 8?
Remove conjunctiva
Step 9 ?
Assess for further haemorrhage
Step 10?
Close the deeper orbit
Step 11?
Close the skin
hat complications to enucleation?
- Woudn breakdown
- Infection
- Cyst formation
- subcutaneous air -> forced up NL duct when breathing in brachy
What are some complicating factors?
- Soft glove -> ruptured glove much harder to remove
- Neoplasia
- Infected cornea -> risk of site contamination
Use of intrascleral prosthesis?
● Retains a cosmetically acceptable eye
● Increased risk of failure
● Poor tissue preservation for histopathology
