This document discusses various techniques for providing anesthesia during ophthalmic surgery, including sub-tenon's block, peribulbar block, retrobulbar block, and subconjunctival block. It describes the aims, sites of injection, patient positioning, local anesthetic agents used, techniques, advantages, disadvantages, and potential complications for each type of block. The sub-tenon's block provides akinesia and anesthesia through injection into the subtenon space using lignocaine or bupivacaine. The peribulbar and retrobulbar blocks both aim to block orbital nerves but through different injection sites and techniques. The subconjunctival block only provides anterior segment anesthesia without akinesia.

1. Anesthesia for
Ophthalmic Surgery
Sub-tenon, Peribulbar & Retrobulbar
dr. Frenky R. de Jesus
National Eye Centre
Postgraduate diploma in Ophthalmology

2. Anesthesia for Ophthalmic Surgery
dr. Frenky
ANESTHESIA
Infiltration Intracameral Topical Nerve Blocks
Retrobulbar
Block
Peribulbar
Block
Subtenon’s
Block
Subconjunctival
Block
Local General
Classification

3. Anesthesia for Ophthalmic Surgery
dr. Frenky
Generic name
(trade name)
Concentration
(Max Dose)
Onset of
action
Duration of
action
Mayor advantages /
disadvantages
0.5% - 2%
(500mg)
4-5 min
• 40-60 min
• 120 min (with
epinephrine)
Spreads readily without
hyaloronidase/
Increased BP with
hyaloronidase.
0.25% - 0.75% 5-10 min
• 5-6 hrs.
• 8-12 hrs (with
epinephrine)
Long duration of
action/increased
toxicity of extra ocular
muscles.
0.5% - 2% 4-5 min 2-3 hrs.
Peripheral nerve block
Less neurotoxicity
Local Anesthetic agents
Lidocaine*
(Xylocaine,
anestacaine)
Bupivacaine*
(Sensorcaine,
Marcaine)
Mepivacaine*
(Carbocaine)
Anesthetic drugs

4. Anesthesia for Ophthalmic Surgery
dr. Frenky
Anesthesia routes
1. Sub-tenon route
2. Retrobulbar route
3. Peribulbar route

5. Anesthesia for Ophthalmic Surgery
dr. Frenky
AIM:
• Provides akinesia and anesthesia to the
globe.
• Injection Subtenon space.
SITE OF INJECTION:
• The commonest approach is by the
inferonasal quadrant or
inferitemporal.
POSITION OF PATIENT:
• Supine in primary gaze.
L/A AGENTS:
• Lignocaine 2%
• Bupivacaine 0.75%
Along with:
• Hyaluronide: 3-7 UI/ml.
• Adrenaline: 1:200,000.
TECHNIQUE:
• Using 21G Rycroft cannula.
• The eye is cleaned and the patient asked
to look upwards and outwards.
• The conjunctiva is anesthetized first with
drops of the local anesthetic of choice.
Parabulbar/Sub-tenon’s Block

6. Anesthesia for Ophthalmic Surgery
dr. Frenky
Techniques…
Step 1:
Grab conjunctiva
and Tenon’s capsule
with Colibri forceps.
• Small cut with
Wetscot Schissors.
• Button hole
formed 5-10mm
from the limbus.
Step 2:
• Blunt curve’s
posterior sub-
tenon’s cannula with
local anesthesia.
• Move along the
curvature of the
sclera
Step 3:
Inject anesthetic
agent into sub-
tenon space.
Step 4:

7. Anesthesia for Ophthalmic Surgery
dr. Frenky
Disadvantages
• Less painful.
• Better analgesia than topical
anesthesia.
• Complications rarely serious.
• No increase in IOP.
• Surgery can begin immediately lasts
for 60 min and supplemental
anesthetic agent can be given.
• The globe can be voluntarily moved
at the surgeon’s instruction.
• Low dose and low volume of
anesthetic agent are used.
• The local anesthetic agent must be
injected into the capsule - double
perforation of the capsule results in
anesthetic leaking out, which
decreases the effectiveness of the
block.
• Although it is an advantage that the
globe can be moves under
instruction, it is important the eye is
not moved at other times - the use
of stabilizing sutures is advised.
• Chemosis and subconjunctival.
Advantages
Parabulbar/Sub-tenon’s Block

8. Anesthesia for Ophthalmic Surgery
dr. Frenky
Complications
Subconjunctival swelling. Subconjunctival Hemorrhage.

9. Anesthesia for Ophthalmic Surgery
dr. Frenky
Peribulbar Block
AIM:
• Injection outside the muscle cone.
• Block the orbital nerve, including 4th CN.
• Provides akinesia and anesthesia to the
globe.
SITE OF INJECTION:
• Inferotemporal quadrant.
• At junction of lateral 1/3 and medial
2/3 of inferior orbital margin.
POSITION OF PATIENT:
• Supine in primary gaze.
L/A AGENTS:
• Lignocaine 2%
• Bupivacaine 0.75%
Along with:
• Hyaluronide: 3-7 UI/ml.
• Adrenaline: 1:200,000.
TECHNIQUE:
• Using 22G 35 mm.
• Palpate inferior orbital rim.
• Place needle perpendicular through skin.
• Located needle 1/3 distance from lateral
medial canthus.
• Place just superior to inferior orbital rim.

10. Anesthesia for Ophthalmic Surgery
dr. Frenky
Techniques…
TECHNIQUE:
• Using 22G 35 mm.
• Palpate inferior orbital rim.
• Place needle perpendicular through
skin.
• Located needle 1/3 distance from
lateral medial canthus.
• Place just superior to inferior orbital rim.

11. Anesthesia for Ophthalmic Surgery
dr. Frenky
Techniques
1st Injection:
• Place just superior to inferior orbital rim.
• Advance parallel to the orbital floor, perforating
septum.
• Hub of needle should not go to beyond inferior
orbital rim.
• Aspirate to avoid blood vessel.
• Inject 3ml of anesthetic solution.
• Apply pressure to prevent hemorrhage and facilitate
diffusion of anesthetic.
2nd Injection:
• Locate needle by supraorbital notch, place needle
just inferior to the superior orbital rim, advance
needle straight back.
• Inject 3ml of anesthetic.

12. Anesthesia for Ophthalmic Surgery
dr. Frenky
Disadvantages
• The risk is low. • The quality of akinesia and
anesthesia may not be as good as
with retrobulbar block.
• Often more than one injection is
required.
• Chemosis occurs in 80% of cases,
which make operating operating
condition difficult.
Advantages
Peribulbar Block

13. Anesthesia for Ophthalmic Surgery
dr. Frenky
Complications
• Lids trauma.
• Ptosis.
• Muscle damage.
• Globe penetration.
• Retrobulbar hemorrhage.
• Optic nerve damage.
• Brainstem anesthesia.

14. Anesthesia for Ophthalmic Surgery
dr. Frenky
Retrobulbar Block
AIM:
• Injected the muscle cone to block:
• Ciliary nerve and ganglion.
• 3rd, 4th, 6th CN before enter to posterior
intrazonal space.
• Provides akinesia and anesthesia to the
globe.
TECHNIQUE:
• Using 22G 35 mm.
• Palpate inferior orbital rim.
• Place needle perpendicular through skin.
• Located needle 1/3 distance from lateral
medial canthus.
• Place just superior to inferior orbital rim.
POSITION OF PATIENT:
• Supine in primary gaze.
SITE OF INJECTION:
• Inferotemporal quadrant.
• At junction of lateral 1/3 and medial 2/3 of
inferior orbital margin.
L/A AGENTS:
• Lignocaine 2%
• Bupivacaine 0.75%
Along with:
• Vasoconstrictor (Epinephrine).

15. Anesthesia for Ophthalmic Surgery
dr. Frenky
• Inject 0.5ml of solution s/c to reduce pain when orbital septum is pierced.
• Advance needle parallel to orbital floor perforating the septum.
• After equater of globe is passed, direct needle superonasally at 30 degree angle,
advance, piercing intermuscular septum and enter muscle cone.
• Inject 4-5ml of anesthetic.
Techniques…

16. Anesthesia for Ophthalmic Surgery
dr. Frenky
Disadvantages
• Reliable for producing excellent
anesthesia and akinesia.
• The onset is quicker than with
peribulbar (5 minutes).
• Low volumes of anesthetic, results
in a lower intraorbital tension and
less chemosis than with peribulbar
blocks.
• Loss of visual acuity occurs in a
greater number of patients
compared to peribulbar blocks,
though this can be volume
dependent.
• The main disadvantage is that the
complication rate is higher than for
peribulbar blocks – the reason for
the development of the peribulbar
block.
Advantages
Retrobulbar Block

17. Anesthesia for Ophthalmic Surgery
dr. Frenky
Complications
• Retrobulbar hemorrhage.
• Ocular perforation.
• Subaracnoid and intradural injection.
• Muscle complication: ptosis from elevator aponeurosis
dehiscence, entropion and diplopia following EOM injection.
• Oculocardiac reflex.

18. Anesthesia for Ophthalmic Surgery
dr. Frenky
Subconjunctival Block
AIM:
• Anterior segment is blocked but no
akinesia.
TECHNIQUE:
• Asepsia with Betadine.
• Apply anesthesia drop.
• Using 27G or 30G needle, even 26G
needle.
• Injected the block under the
conjunctiva.POSITION OF PATIENT:
• Supine in primary gaze.
SITE OF INJECTION:
• At posterior to phase incision/
perilimbal conjunctiva.
L/A AGENTS:
• Lignocaine 2%
• Bupivacaine 0.75%

19. Anesthesia for Ophthalmic Surgery
dr. Frenky
Disadvantages
• Cost effective.
• Not affected EOM.
• Visual acuity
• Avoidance of complications: Globe
rupture, nerve damage.
• No akinesia.
• Not suitable for extended surgery.
Advantages
Subconjunctiva Block

20. Anesthesia for Ophthalmic Surgery
dr. Frenky
Complications
Subconjunctival Hemorrhage.

21. Anesthesia for Ophthalmic Surgery
dr. Frenky
THANK YOU