Anesthesia for eye surgery presents unique challenges. The anesthesiologist must have detailed knowledge of ocular anatomy, physiology, and pharmacology to prepare an appropriate anesthesia plan. They must regulate intraocular pressure, prevent oculocardiac reflex, and ensure smooth intubation and extubation. Regional techniques may be preferable to general anesthesia in some cases to avoid risks of increases in intraocular pressure.

1. PRESENTER : DR. RAJESH .M
MODERATOR : DR. RONY MATHEW
HOD : DR. ARUN KUMAR A
SSIMS & RC , Davangere

2. Anesthesia for EYE surgery presents
many unique challenges.
 In addition to possessing technical
expertise, the anesthesiologist must
have detailed knowledge of ocular
anatomy, physiology, and pharmacology
to prepare appropriate anesthesia plan.

3.  Ocular anatomy
Physiology of intraocular pressure and
effect of anesthetic drug on it,
Systemic effects of ophthalmic drugs
 Technique of anesthesia: advantage and
limitations
 Pre op evaluation
 General anaesthesia
 Complications
 Oculo cardiac reflex and other reflex
 Specific considerations for eye
surgeries

4.  Eye is a sphere measuring appropriately 24mm
in diameter
 The mean distance from the inferior orbital
margin to The apex is 55 mm.
 3 layers : sclera , uvea , retina
 Movement of the globe is controlled by the
six extra-ocular muscles.
 The eye is hollow sphere with a rigid wall.
 Intraocular pressure 12—20 mmHg

7.  Middle layer uvea has 3 structures : choroid ,
iris and ciliary body .
 Choroid is a layer of blood vessels located
posteriorly.
 Bleeding in this layer is one cause of
intraoperative expulsive haemorrhage .
 Iris controls light entry through pupil by
change in its size
 Sympathetic : dilates pupil
 Parasympathetic : constricts the pupil.

8. Centre of eye is filled with vitreous gel .
It has attachments to blood vessels and
optic nerve.
Traction of vitreous on retina Is a cause for
retinal detachment.

9. Tenon’s fascia surrounds the eyeball.
It arises from corneo scleral junction ( the
limbus) , fuses posteriorly with the dural
sheath of the optic nerve and seperates
the globe from the intra and extra conal fat
which surrounds the ocular muscles
The extraocular muscles and nerves
penetrate this fascia

10.  Cranial nerve II : optic nerve carries signals
from retina
 III (oculomotor) , IV (trochlear) , VI (
abducens) control the extra ocular muscles.
 Facial nerve (VII) exits at the skull from the
stylomastoid foramen . It supplies motor
innervation to the orbicularis muscle via the
zygomatic branch.
 Local anesthetic block of facial nerve can
prevent lid squeezing

14. The eye is hollow sphere with a rigid
wall.
Intraocular pressure 12—20 mm Hg
If the contents of the sphere increase,
the intraocular pressure rise.

16. Any anesthetic event that alters these
parameters can affect intraocular
pressure
 Laryngoscopy
 Intubation
 Airway obstruction
 Coughing
 Trendelenburg position

17. Most anesthetic drugs either lower or
have no effect on intraocular pressure.
Inhalational anesthetics decrease
intraocular pressure in proportion to the
depth of anesthesia.
The decrease has multiple causes:
1. A drop in blood pressure reduces
choroidal volume.
2. Relaxation of the extraocular muscles
lowers wall tension
3. pupillary constriction facilitates aqueous
outflow.

19. Iv succinylcholine causes IOP to increase
by 6-12mmhg, this lasts for 5-10mins.
The use of succinylcholine for induction of
anesthesia in cases of open globe injury
with full stomach has been controversial .
Loss of vitreous by succinylcholine has
actually not been reported .

20. Topical ophthalmic drugs can be
absorbed through the conjunctiva, or
they drain through the nasolacrimal
duct and be absorbed through the nasal
mucosa.
 Usage of topical medications can have
implications for the anesthesiologist

21.  Acetazolamide : used for glaucoma, induces
alkaline diuresis and causes potassium depletion.
 Atropine :The 1% solution contains 0.2 to 0.5
mg of atropine per drop
tachycardia, dry skin, agitation, fever
 Ectothiopate : topical anticholinesterase used to
maintain miosis in treatment of glaucoma : total
body inhibition of plasma cholinesterase.
 Mannitol : catheter required to avoid bladder
distension .
 Increases circulatory volume , can lead to CHF in
patients with poor LV function.

22. Phenylephrine : 10%: severe hypertension
2.5%: safer , but can exacerbate hypertension.
Pilocarpine & ach : bradycardia & acute
bronchospasm.
Timolol : bradyardia , bronchospasm ,
exacerbation of CCF .

23. The Oculocardiac Reflex(OCR) is
manifested by
Bradycardia
 Bigeminy
 Ectopics
 Nodal rhythm
 Atrioventricular block
 Cardiac arrest
Ventricular fibrillation

24. Caused By:
Traction on the extraocular muscles
(medial rectus)
 Ocular manipulation
 Manual pressure on the globe
The OCR is seen during:
Eye muscle surgery
Detached retina repair
Enucleation

25. Factors contributing to the incidence of
the oculocardiac reflex:
Preoperative anxiety
Hypoxia
Hypercarbia
Increased vagal tone owing to age

26.  Afferent pathway
Short and long ciliary
nerves
Ciliary ganglion
via ophthalmic
division of trigeminal
nerve
Trigeminal sensory
nucleus
 Efferent pathway
Nucleus of vagus
Cardiac branches
Bradycardia

27. ❖One should not panic
❖Ask surgeon to stop all the manipulations
❖Instil local xylocaine(4%)over the surgical
site.
❖Intravenous Atropine 15 micro grams / Kg or
intravenous Glycopyrrolate 7.5 micro grams /
Kg
Ensure
 depth of general anesthesia
 normocapnia
 surgical manipulation is gentle

28. May cause shallow breathing, reduced
respiratory rate and even full
respiratory arrest.
Trigemino vagal reflex- connection
exists between the trigeminal sensory
nucleus and the pneumotactic centre in
the pons and medullary respiratory
centre.
 Commonly seen in strabismus surgery
 Atropine has no effect.

29. It is likely responsible for the high
incidence of vomiting after squint
surgery (60-90%).
Trigemino-vagal reflex with traction on
the extraocular muscles stimulating the
afferent arc.
Antiemetics may reduce the incidence,
a regional block technique provides the
best prophylaxis

30.  Challenges for the anaesthesiologist are
 Akinesia
 Analgesia
 Minimal Bleeding
 Awareness of drug interactions
 Regulation of intraocular pressure
 Prevention of the oculocardiac reflex
 Management of oculocardiac reflex
 Control of intraocular gas expansion
 Smooth emergence

31. History Example Problem optimisation
Previous
surgery
Scleral explant Limit insertion of
tenon cannula
Use of topical
anesthetic or
peribulbar block
CNS Tremor/movement
disorder/vertigo/anxi
ety/confusion
Unable to lie still Consider GA
CVS Orthopnea
Hypertension
Unable to lie flat
Bleeding risk
Table adjustment
Continue antihtn
RS Dyspnea Unable to lie flat Medical
optimisation
COPD Hypoxaemia 02 + careful
draping to prevent
retention

32. Cataract surgery can be performed safely
while maintaining patients receiving
warfarin .
For intermediate risk procedures such as
some glaucoma procedures , stopping
warfarin for 4 days preoperatively is
indicated .
For high risk cases for hemorrhage or
thrombosis , conversion from warfarin to
heparin may be required.

33.  Facial nerve block
 Retrobulbar block
 Peribulbar block
 Sub Tenon block
 Topical anesthesia
 General anesthesia

34. It is performed when complete akinesis of
the eyelids is desired.
 modified van lint block
O’brien block
Nadbath rehman block

35. The needle is placed 1cm lateral to the
orbital rim , and 2 to 4ml of anesthetic is
injected deep on the periosteum just lateral
to superolateral and inferolateral orbital rim
.
Disadvantages : discomfort , proximity to
eye , postop echymoses

37. Mandibular condyle is palpated inferior to
the posterior zygomatic process and
anterior to the tragus of the ear as the
patient opens and closes the jaw .
Needle is inserted perpendicular to the
skin approximately 1cm to the periosteum.
As the needle is withdrawn 3ml of
anesthetic is injected.

39.  A12mm , 25G needle is inserted perpendicular to
the skin between the mastoid process and the
posterior border of the mandible .
 Needle is advanced its full length and after careful
aspiration 3ml of anesthetic injected as the needle
is withdrawn.
 Blocks entire trunk of facial nerve .
 Patient should be told to expect a lower facial
droop for several hours postoperatively .
 Disadvantages: proximity to important structures
such as carotid artery and 12th nerve

42. Drug Characteristics
Lignocaine 2% Onset : 5-10min
Duration of anesthesia : 30-60mins
Duration of analgesia : 1-2hr
Bupivacaine 0.5% Onset : 10-15min
Duration of anesthesia : 2-4hr
Duration of analgesia : 6-8hr
Ropivacaine 0.75% Onset : 10-15min
Duration of anesthesia : 1.5-2hrs
Duration of analgesia: 4-6hrs
Lignocaine 2% + bupivcaine 0.5% Onset : 5-10mins
Duration of anesthesia : 1-3hrs
Duration of analgesia: -6hrs

43.  Provides excellent akinesia and anesthesia for the eye .
 3cm , 23-25G atkinson needle is recommended to protect
against ocular perforation.
 Needle placed at the junction of inferior and lateral wall of orbit
just above the inferior orbital rim .
 Needle advanced approximately 15mm along the wall of the
orbit until it is past the equator of the eye .
 Turned superiorly to aim towards the superior orbit.
 Needle is advanced until it enters between the extraocular
muscles. 2-3ml of anesthetic solution is injected .

45. Retrobulbar haemorrhage
Proptosis
Subconjuctival echymoses
Monitoing of IOP : mandatory , if increased
pressure lateral canthotomy is performed
to decompress orbit.

47.  Accidental intra arterial injection can give high
brain levels via retrograde flow in the internal
carotid artery .
 CNS excitation , seizures and respiratory
arrest are reported.
 It is thought to be due to injection into optic
nerve sheath which is continuous with the
subarachnoid space.
 Optic nerve damage and ocular perforation

48.  A blunt 23G 7/8 inch atkinson needle is placed at the
junction of middle and lateral thirds of the lower lid just
above inferior orbital rim .
 1ml is put just below orbital septum
 3ml at equator
 2ml posterior outside the muscle cone.
 If no bulge at superior nasal lid area , 2nd injection of 2-
3ml is administered inferonasally.
 Disadvantages : longer onset (9-12mins) and lower
incidence of complete akinesia .

51.  Technique using blunt cannula under the fascia of
tenon.
 Using topical anesthesia with sedation , a speculum is
placed to retract the lid.
 A 2-3mm spot of cautery can be made 5mm from the
limbus in the inferonasal and the inferolateral quadrant .
 A 2mm snip is made in the conjuctiva with blunt
dissection through the fascia of tenon.
 A blunt cannula is directed under fascia of tenon
posteriorly , but not beyond the equator of the globe
with injection of 1-3ml of local anesthetic .
 Excellent analgesia

56.  Cataract surgeries.
Drugs used are
 Tetracaine 0.5%
 Lidocaine 4%
 0.5% proparacaine
 They block trigeminal nerve endings in
cornea and conjuctiva leaving the intraocular
structures in the anterior segment
unanesthetised.

57. Manipulation of iris and stretching of ciliary
and zonular tissues during surgery can
irritate the ciliary nerves resulting in
discomfort.
Combining 0.5ml of 1% lignocaine injected
through side port incision after evacuation
of aqueous (intrcameral anesthesia).
Disadvantages : visual sensations , anxiety
, discomfort

58. Goals :
Smooth intubation
Stable IOP
Avoidance of oculocardiac reflexes
Balanced opioid anesthesia
Smooth extubation
Use of LMA

59. In fluid gas exchange : surgeon injects
intravitreal bubble to tamponade retina
against wall of globe
N20 diffuses and causes bubble expansion
and leads to increase IOP
N20 should be shut for 15mins before
placing sulfur hexaflouride bubble and
should be avoided for 7-10 days thereafter.

60. A patient with eye trauma is a challenge to
anesthesia provider.
Dilemma is to protect patient from
pulmonary aspiration of gastric contents &
to protect eye from acute changes in IOP
which could cause vitreous loss , retinal
detachment and blindness.
Rapid sequence induction to be done .

61. Increase in IOP can cause loss of ocular
contents.
It may be difficult to fit a facemask when
the eye is covered with dressing.
Smooth intubation and extubation needed.
Avoid hypoxia and hypercarbia.
Hypertermia can lead to increase IOP
Avoid ketamine

62. Premedication :
 -analgesics as required
 -atropine at the time of induction.
 Ondansetron to prevent nausea/vomiting
 Induction with IV thiopentone and pancuronium.
 Cricoid pressure to avoid aspiration.
 Cuffed ET tube preferred
 Lignocaine and beta blocker to blunt the
cardiovascular and IOP response to
laryngoscopy and intubation

63. Control ventilation and maintain
anesthesia with N20 and halothane .
Adequate reversal in the end
Fully awake extubation in lateral position.
( stoelting’s anesthesia nd co exsting
diseases -2nd south asian edition)

64. Regional techniques can be performed
Factors to consider include:
Size of the perforation : small punctures
have higher resistance to vitreous loss with
changes in IOP.
Pulmonary status
NPO status
Length of procedure.

65. Small children may require examination
under anesthesia.
Im ketamine is the choice when iv is
problematic.
Ketamine is preferred because it does not
reduce IOP as other barbiturates do.
Most commone eye surgery is for
strabismus.


66. Droperidol 5-75mcg/kg for postop nausea
and vomiting.
If force ductal testing is used to asses the
muscle tightness , the surgeon should be
notified if succinylcholine is used.
Succinylcholine causes a tonic increase in
eye muscle tone which resolves in
approximately 20mins.
Malignant hyperthermia and myotonic
dystrophy are assocciated with strabismus.

67. Corneal abrasion
Chemical injury
Photophobia
Blurred vision
Haemorrhagic retinopathy
Retinal ischemia
Retinal artery occlusion
Ischemic optic neuropathy
Cortical blindness
Acute glaucoma
ptosis

68. Miller’s anesthesia – 8th edition
Stoelting’s anesthesia and coeisting
diseases – 2nd south asian edition

69. Thank you !!!