This document discusses anaesthesia for eye surgery. It begins with a brief history of local anaesthesia for eye surgery and the development of regional techniques. It then covers anatomy of the eye, orbit and surrounding structures. Factors that influence intraocular pressure are explained, including effects of anaesthetic drugs and muscle relaxants. The document discusses pre-operative evaluation and anaesthetic management considerations for eye surgery, including different anaesthetic techniques and their indications. Post-operative complications are also mentioned.

1. ANAESTHESIA FOR EYE
SURGERY
Dr Ramprasad Gorai
PGT, Department of Anaesthesia, Critical Care & Pain
R.G.Kar Medical College

2.  Anatomy of Eye , Physiology Of IOP
 Anaesthetic Ramification of Ophthalmic Drugs
 Pre-op Evaluation
 Anaesthtic Management Of Specific Situation
 Post-op Complications
We will discuss on-

3. History---
Karl Koller
 Karl Koller Austrian ophthalmologist
introduced cocaine as a local
anaesthetic for eye surgery.
 Koller was reputedly nick named
"Coca Koller" for his association with
the drug.

4. Hermann Jakob Knapp
1st Describe Needle Based
Ophthalmic Regional Anaesthesia.
Atkinson,introduced the retrobulbar block in early 20th
century.

5. Orbit
ORBIT-
1.Eye ball
2.Optic Nerve
3.Extra-Ocular Muscles
4.Vessels
5.Fat
6.Ciliary Ganglion
7.Occulomotor,Trochle
ar,Abducent Nerves.
8.Lacrymal,Frontal,nas
ociliary br of
Trigeminal Nerve.

6. Anatomy of eye
1.Outer fibrous -SCLERA &
CORNEA
2.Middle Vascular-UVEAL
TISSUES (IRIS, CILIARY BODY,
CHOROID)
3.Inner Neuro-Sensory -
RETINA
TWO CAVITY-
1.Anterior- 2 chamber(aqueous)
2.Posterior-(Vitreous)
CORNEA- 5 layers
1.Epithelium
2.Bowmans capsule
3.Stroma
4.Descemet Membrane
5.Endothelium
OPTIC NERVE-4 parts
1.Intra-Ocular(1mm)
2.Intra-Orbital(30mm)
3.Intra-Canalicular(6-9mm)
4.Intra-Cranial(10mm)

7. Cont..
 Four rectus muscles arise
from the Apex of orbit from a
Common tendinous
Ring(Annulus of Zinn).
 All by 3 (Occulomotor)
 Except-LR6SO4
 Sensory supply to orbit-from
opthalmic division Trigeminal
nerve
PERIPHERAL
(peribulbar
CENTRAL
(retrobulbar)
The mean distance from the inferior orbital margin to The apex is 55 mm.
(This has important implications when injections are made into the orbit.)

8.  The blood supply to the retina and optic nerve depends on the
intraocular perfusion pressure(IPP).
 IPP=MAP-IOP
 Normal IOP = 10-20 mm of Hg
 IOP varies 1 to 2 mm Hg with each cardiac contraction. Also, a diurnal
variation of 2-5 mm Hg is observed
 High IOP—1.Impair blood supply, 2.prolapse intraocular content
in open eye—> Permanent vision loss.
Physiology of Intra Ocular Pressure-

9. How aqueous humour formed?
 Two third (2/3)-is formed in the posterior chamber by the ciliary
body in an active secretory process involving both the carbonic
anhydrase and the cytochrome oxidase systems
 The remaining third (1/3)- is formed by passive filtration from the
vessels on the anterior surface of the iris
Rate of Production?
@ 2 μL/min.
Pathway?
 Aqueous humour flow from posterior to anterior chamber
through Pupil & then drain out by 2 route- 1.Trabecular
outflow(90%) 2.Uveo-scleral outflow(10%).
 Mainly-Trabeular meshwork—Schlemms canal– episcleral vein.

11. Factor affecting IOP-
CVP—affect
more(Marked)
PaCO2-Moderate

12.  Coughing, straining, or vomiting- can increase IOP to 30 to 40 mm Hg.
 Endotracheal intubation can cause similar increases. These increases are
transient and are relatively innocuous in a closed eye. In an open eye,
(such as after traumatic injury or during cataract surgery) these
increases can lead to loss of intraocular contents, hemorrhage, and
permanent vision loss.
 Extrinsic compression of the eye-also increases the IOP.
 A normal blink increases the IOP by 10 mm Hg.
 A forceful lid squeeze can increase IOP to more than 50 mm Hg.
 A poorly placed anesthesia mask can put enough pressure on the eye to
reduce blood flow to zero.
Other factor affecting IOP-

13.  Deep inhaled or intravenous (e.g., propofol) anesthesia -
causes a dose-related reduction in IOP by 30% to 40%.
 Opioids have little effect.
 Atropine (usual dose)-do not cause a significant increase in
IOP, even in patients with open-angle glaucoma.
 Ketamine – Controversy
 Succinylcholine causes IOP to increase by 6 to 12 mm Hg;
this lasts for 5 to 10 minutes
Anesthesia Drug & IOP-

14.  ketamine initially was believed to increase IOP significantly,
as measured by indentation tonometry.
 More Recent Study using applanation tonometry, shows no
significant rise in IOP (after 2mg/kg IV Ketamine in adult &
8mg/kg IM ketamine in Pediatric patient).
 Rather Ketamine may cause Nystagmus & Blepharospasm
which limit its use in Eye surgery.
Effect of Ketamine-

15. Nondepolarizing- 2 effect
Direct-Lower IOP by Relaxing Extraocular muscles.
Indirectly-Paralysis of respiratory muscles causes alveolar
hypoventilation which increase IOP.
Depolarizing-
Succinylcholine increase IOP about 8 mm Hg within 1-4 Minute &
return to baseline within 7 min due to-
1.Tonic contraction of Extraocular muscles,
2.Choroidal Vascular dilation,
3.Relaxation of orbital smooth muscles.
Muscle Relaxant-

17. Anaesthetic Ramifications of
Ophthalmic Drugs

18.  Systemic absorption of topical ophthalmic drugs may occur
from either the conjunctiva or the nasal mucosa after the
drainage through the nasolacrimal duct.
 Occluding the nasolacrimal duct by pressing on the inner
canthus of the eye for a few minutes after each instillation
greatly decreases systemic absorption ,thereby systemic
side effects.

19.  Carbonic anhydrase inhibitor with Renal tubular
effect
 Popular Antiglaucoma drug.
 It also induces an alkaline diuresis that can result in
potassium depletion.
 Patients taking acetazolamide should have
electrolytes checked preoperatively.
Acetazolamide

20. Atropine E/D-Used for Mydriasis & Cycloplegia.
 can cause tachycardia, dry skin, fever, and agitation.
 Overdose can be treated with incremental doses of
physostigmine.
Timolol maleate – Non-selective topical β-blocker
 Popular anti glaucoma drug.
 Systemic absorption causes-bradycardia,
bronchospasm,exacerbation of congestive heart failure (especilly
in COPD pts) ,execerbation of Myasthenia gravis.
Betaxolol- Beta 1 blocker, More Oculospeific, Minimal Systemic Effect.

21.  Long acting topical anticholin-esterase drug
 Used- to maintain miosis in the treatment of glaucoma.
 Systemic absorption leads to total body inhibition of plasma
cholinesterase.
 Subsequent administration of succinylcholine can cause
prolonged muscle paralysis.
 Inhibition of the metabolism of ester-type local anesthetics
may predispose to local anesthetic toxicity.
 Echothiophate is a long-acting. A return toward normal
enzyme activity can take 4 to 6 weeks after discontinuation
of the drug.
Echothiophate

22. Phenylephrine is an α-adrenergic agonist
 Applied topically to dilate the pupil.
 Systemic absorption of the 10% solution is associated with
severe hypertension,Headache,Tachycardia
 In CAD patient ,10% drop application may cause MI .
Pilocarpine and acetylcholine are cholinergic drugs used to
constrict the pupil.
 can cause bradycardia and acute broncho-spasm

23.  Mannitol is an osmotic diuretic that causes a decrease in IOP
lasting 5 to 6 hours. (Dose= 1.5 gm/kg given over 30-60 min)
 Patients who receive mannitol during surgery may need a
urinary catheter to avoid over-distention of the bladder.
 Mannitol causes an increase in the circulating blood volume,
which can lead to congestive heart failure (in patients with
poor ventricular function),Pulmonary edema,Hypo or
Hypertension,Myocardial ischemia,Renal faliure.

25. Pre Operative Evaluation

26.  Comorbidity-DM/HTN/IHD/COPD/OSA.
 Fasting Status
 Allergies & Drug Hypersensitivity.
 Current Daily Medication.
 Anticoagulant use.
HISTORY-

27.  Stage 3 of severe hypertension is defined as a
systolic BP ≥180 mm Hg or
diastolic BP ≥110 mm Hg .
 Elective procedures in patients with sustained
stage 3 hypertension should be delayed until
after 2 weeks of antihypertensive therapy.
What to do if patient is Hypertensive?

28.  Risk of Thrombosis & Bleeding should assess.
 continuing warfarin in cataract surgery was associated with an
increased risk of bleeding, but almost all were self-limiting and not
clinically relevant.
What to do if patient is on Anticoagulant?
LOW RISK INTERMEDIATE RISK HIGH RISK
Cataract Glaucoma,
Vitreoretinal,
Corneal transplant
Orbital,
Occuloplastc surgery
Continue
Warfarin
Stop warfarin 4 day prior
to OT
Conversion to
Heparin

29. Delay Elective Surgery –for at least-
4-6 weeks ---if Bare Metal Stent
12 Months ----if Drug Eluting Stent
What to do if patient have Stent?

30.  ASA task force on preoperative evaluation concluded that
Routine preoperative tests are commonly not useful in
assessing and managing patients’ perioperative experience.
 Recent Multi-centric Study----“routine” testing does not
improve patient safety or outcome in cataract surgery.
 So, patients having cataract surgery need no preoperative
evaluation.
What Preoperative Investigation to do?

31. Anaesthesia for Ophthalamic Surgery

32.  Surgeon work near to airway/Head-end.
 Most patient are Elderly age gr having associated Comorbidity
(DM/HTN/CAD/COPD etc)
 Wide Fluctuation of Intraocular Pressure by multiple factors.
 Risk of aspiration (eg-Full stomach open globe injury).
 Systemic effect of Ophthalmic Drugs.
Problems in Ophthalmic Anaesthesia

33.  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
Goal of Ophthalmic Anaesthesia-

34. Types of ocular anaesthesia
 General anaesthesia
 Local anaesthesia
Topical
Regional
Peribulbar block
Retro-bulbar block
Episcleral or Sub-Tenons block
Facial block
Frontal block

35. The choice of general v/s local anesthesia is made
on the basis of
the duration of the surgery,
the relative risks and benefits of each technique
for the patient,
patient preference.
Neither technique has been shown to be safer.
GENERAL VERSUS LOCAL
ANESTHESIA

36. GENERAL ANAESTHESIA
FOR OCULAR SURGERY
INDICATION:
1. In children and infant
2. Anxious & uncooperative
patient
3. Mentally retarded adult
4. Patient’s preference
ADVANTAGES:
1. safe operative environment
2. Complete akinesia
3. Controlled intra-ocular pressure
4. For bi-lateral surgery
5. Avoiding complications of L/A

37.  Nitrous oxide presents a special problem in some vitreoretinal
Procedures-where fluid-gas exchange technique used (surgeon injects
an intra-vitreal poorly soluble bubble to tamponade the retina against
the wall of the globe).
 Sulfur hexafluoride is a poorly soluble agent used commnly.Nitrous
oxide diffuses and causes bubble expansion & potential for dangerous
increases in IOP. Nitrous oxide should be shut off for 15 minutes
before placing the sulfur hexafluoride bubble and should be avoided
for 7 to 10 days thereafter.
 newer drug, perfluoropropane (C3F8) can persist for weeks. In this
case, nitrous oxide should be avoided for at least 1 month, or until the
bubble is resorbed.
Nitrous Oxide in Vitreoretinal Surgery-

38.  acts by- producing reversible block to the transmission of peripheral
nerve impulses.
 Advantages-
1.It avoids the potential complications of retrobulbar and peribulbar
injection/GA.
2.most rapid visual rehabilitation,
 Disadvantages –
1.eye movement during surgery,
2.patient anxiety and discomfort.
 Drugs-Tetracaine 0.5% and lignocaine 4%.
 Patient Selection-
A confident, calm, and cooperative patient usually does well.
A nervous, hypersensitive patient may be a better candidate for
another technique.
TOPICAL ANAESTHESIA

39. Most popular now a days
AIM:
Injected into peribulbar space
Spreads to lid and other spaces
Produces globe and orbicularis akinesia and anaesthesia.
L/A agent :
o Lignocaine 2%
o Bupivacaine 0.75%
o Ropivacaine
Along with
o Hyaluronidase 3-7 IU/ml( Hydrolyse connective tisssue polysaccharides---
Better spread)
o Adranaline 1: 200,000 (reduced bleeding + prolong anesthesia)
PERIBULBAR BLOCK

40. VOLUME :8-10 ml (approximately)
NEEDLE-
blunt, 23-gauge, 7/8-inch Atkinson needle
TECHNIQUE-
Deep sedation, topical anesthesia, 2 trans-conjunctival injection.
INSERTION POINT:
 1st - Junction of medial 2/3rd and lateral 1/3rd of lower lid adjacent
& Parallel to orbital floor
 2nd - just medial to medial canthus
USE-
Cataract, Glaucoma, Keratoplasty ,Vitreoretinal surg, Strabismus Surg

41. AIM:
Injected in muscle cone to block
 Ciliary nerve and ganglion
 3rd , 4th & 6th cranial nerves
 provides - akinesia and
anaesthesia of the globe.
POSITION OF PATIENT:
Supine and in primary gaze
SITE OF INJECTION:
In the lower lid margin just above a point between medial
2/3rd & lateral 1/3rd of lower orbital margin
RETROBULBAR BLOCK

42. DIRECTION OF NEEDLE-
backward , upwards and medially towards apex of orbit
SUCCESS- successful retrobulbar block is accompanied by
anesthesia, akinesia, and abolishment of the oculocephalic reflex (ie,
a blocked eye does not move during head turning).
VOLUME: 2 – 5 ml usually
ADVANTAGES:
 Complete akinesia
 Dilatation of pupil
 Adequate and quicker anaesthesia
 Minimal amount of agent required.

43.  Deep Sedation( Propofol+ Remifentanyl)
 Topical anesthesia (4% lignocaine)
 A blunt-tipped 25-gauge needle penetrates the lower lid at the
junction of the middle and lateral one-third of the orbit (usually 0.5
cm medial to the lateral canthus). Awake patients are instructed to
stare supranasally as the needle is advanced 3.5 cm toward the apex
of the muscle cone.
Technique of Retro-bulbar Block-

44.  Tenon’s fascia surrounds the globe and extraocular muscles.
 Local anesthetic (3-4 ml) injected beneath it into the
episcleral space spreads circularly around the sclera and to
the extraocular muscle sheaths .
 A special blunt 25-mm or 19-gauge curved cannula is used
for a sub-Tenon block.
 After topical anesthesia, the conjunctiva is lifted along with
Tenon’s fascia in the inferonasal quadrant with forceps. A
small nick is then made with blunt-tipped scissors, which are
then slide underneath to create a path in Tenon’s fascia.
Sub-Tenon’s (Episcleral) Block

45.  Performed when complete akinesia desired(as in
squint surg).
 Techniques-
1.modified van Lint,
2.Atkinson,
3.O’Brien,
4.Nadbath-Rehman block
FACIAL NERVE BLOCK

46. Complication

47. Complications-
 Retrobulbar haemorrhage
 Globe penetration
 Optic nerve sheath injury
 Optic nerve atrophy
 Decrease visual acuity
 Retinal vascular occlusion
 Brain stem anaesthesia
 Frank convulsion
 Extra ocular muscle palsy
 Trigeminal nerve block
 Oculo-cardiac reflex
 Respiratory arrest

48.  first described by- Aschner and Dagnini in 1908
 Receptor-
1. Traction on the extraocular muscles (mainly Medial Rectus)
2.pressure on the globe.
3.Any stmulation of orbital content even periosteum
 Afferent –Short and long ciliary nerve ciliary ganglion  ophthalmic division of the
trigeminal nerve  sensory nucleus of the trigeminal near the fourth ventricle.
 Integration Centre-Medulla
 Efferent -via the vagus nerve to the heart.
 Effect-1.bradycardia, 2.atrioventricular block, 3.ventricular ectopy, or 4.asystole.
Oculocardiac Reflex

49. Occulo Cardiac Reflex
LCN
SCN
CG TGG
VN
afferent
efferent

50. Management-
1.first ask the surgeon to stop manipulations.
2.The ventilatory status is assessed.
3.If significant bradycardia persists or recurs, intravenous atropine is
administered in 7-μg/kg increments.
4.Rarely, severe bradycardia or asystole require chest compressions(CPR).
Prevention-
1.Pre-treatment with intravenous atropine or glycopyrrolate can be
effective.
Pre-treatment may be indicated in patients with a history of-1. conduction
block, 2.vaso-vagal responses, or 3.β-blocker therapy.
Oculocardiac Reflex

51. Anaesthtic Management Of Specific Situation

52. Issues/Problem-
 Risk of aspiration against the Risk of blindness
(elevated IOP in injured eye --> extrusion of ocular contents)
Plan of Anesthesia-
 Regional anesthesia (eg, retrobulbar block) is relatively
contraindicated in patients with penetrating eye injuries
because injecting local anesthetic behind the globe increases
IOP and may lead to expulsion of intraocular contents.
 Therefore, these patients require general anesthesia—despite
the increased risk of aspiration pneumonia.
1.Approach to a Patient with
an Open Eye & a Full Stomach

53.  1.Exclude other injuries(Skull & Orbital #,ICH,SDH,Abd
bleeding)
 2.Preop Prophylaxis against Aspiration(H2 Antagonist+
Metoclopramide).
 3.Avoid Head down position (which increase IOP).
 4.Avoid pressure on eye ball by face mask.
What precaution to take in Open Globe Injury?

54.  5.RSI- Propofol/Thiopentone ,Scoline/Rocuroneum(if Sugamadex
available)
 [Scoline only moderaely increase IOP,Other measures if done
appropriately then Scoline induced Increase IOP is Insignificant]
 6.Avoid Premature attempt of Intubation as it produce cough,staining
& increase IOP .
 7.Maintain Deep Plane of anaesthesia
 8.Extubate in deep plane with Lignocaine 1.5 mg/kg 90 sec before.

55. What Precaution to take?

56.  Many Eye Surgery done under Topical & Regional Anaesthesia.
 No Preoperative Investigations Required.
 Every Patient Should be assess Clinically before OT for
Comorbidity & Risk assessment.
 Every measure to be taken to prevent rise in IOP.
 In Patient with Open Eye & Full stomach-General Anesthesia is
preferred regardless of Fasting status but All measure to be
taken to prevent Risk of Aspiration and to prevent Rise in IOP.
TAKE HOME MASSAGES

57. THANK YOU