Dentistry

1. Transient diplopia following
maxillary local anaesthetic injection

2. CASE REPORT
 A 26-year-old female was referred for extraction of
her upper left third molar due to irreversible pulpitis.
The patient had no medical concerns contraindicating
the extraction. One cartridge of 1.8 ml 2% lidocaine
with 1:80000 adrenaline was administered with 27-
gaug short needle on non-aspirating syringe. The
tooth was luxated with elevator, and removed with
forceps. Shortly after extraction the patient reported
double vision. Ocular examination revealed normal
pupils, no evidence of ptosis or conjunctivitis. Ocular
movements in all direction were normal except that
the left eye can not abduct past the midline.

3. What has happened?
What is the solution?

4. DIPLOPIA
 Diplopia occurs in two forms:
1. Monocular Diplopia: patient experiences
double vision in only one eye.
2. Binocular Diplopia: It occurs only when both
eyes are working together

5. DIPLOPIA
 Diplopia can be:
1. Horizontal; images beside each other
2. Vertical; images above each other
3. Oblique; images separated horizontally and
vertically

6. DIPLOPIA
 Since much of the vision is binocular, it is
clear that a very high order of coordination of
movements of the two eyes is necessary if
visual images are to fall at all times on
corresponding points in the two retinas and
diplopia is to be avoided.
Ganong, medical physiology 17th ed. 1995

7. Muscles of eye movements
Extraocular muscles
Muscle Cranial Nerve
Medial rectus (MR) Oculomotor (III)
Lateral rectus (LR) Abducent (VI)
Superior rectus (SR) Oculomotor (III)
Inferior rectus (IR) Oculomotor (III)
Superior oblique (SO) Trochlear (IV)
Inferior oblique (IO) Oculomotor (III)

8. Muscles of eye movements
Extraocular muscles

9. Muscles of eye movements
Extraocular muscles
Types of eye movements
pupil moves toward midline Adduction
pupil moves away from midline Abduction
Pupil moves up Elevation
Pupil moves down Depression
Top of pupil moves toward midline Intorsion
Top of pupil moves away from midline Extorsion

10. Muscles of eye movements
Extraocular muscles
Muscle Primary
movement
Secondary
movement
Tertiary
movement
Medial rectus Adduction
Lateral rectus Abduction
Superior rectus Elevation Intorsion Adduction
Inferior rectus Depression Extorsion Adduction
Superior oblique Intorsion Depression Abduction
Inferior oblique Extorsion Elevation Abduction

11. cardinal positions of gaze
The six cardinal positions are:
 up/right
 up/left
 right
 left
 down/right
 down/left

12. OCULAR COMPLICATIONS OF LOCAL
ANAESTHESIA
 Diplopia (double vision)
 Amaurosis (Blindness)
 Palpebral ptosis (dropping of eyelid)
 Mydriasis (dilation of pupil)
 Miosis (constriction of pupil)
 Horner-like syndrome (ptosis, miosis, enophthalmos and
vascular dilatation of the conjunctiva)

13. OCULAR COMPLICATIONS OF LOCAL
ANAESTHESIA
 For the past 45 years, ocular complications
after middle or posterior alveolar nerve block
were reported twice more frequent than
inferior alveolar nerve block. A literature
review by the author of the present paper
reveals more than 20 cases of ocular
complications after IANB. About two thirds of
cases had ocular complications of diplopia.
Chun-kei Lee 2006
Dental Bulletin

14. OCULAR COMPLICATIONS OF LOCAL
ANAESTHESIA
 In the literature, only very few cases of ocular
complications were reported in children. This may be
due to the temporary effect of the complication and
its rapid recovery without sequelae but it has been
queried that these complications are under-reported.
Moreover, it has been suggested that sudden
monocular amaurosis may pass unnoticed by the
patient and cases of visual disturbance following local
anesthesia in dentistry occur more often than are
recognised.
Chun-kei Lee 2006
Dental Bulletin

15. OCULAR COMPLICATIONS OF LOCAL
ANAESTHESIA
 ophthalmologic complications after dental
anesthesia might be more common than
reported to date. The benign and transient
nature of these conditions and their resolution
without sequelae may be the reason for this
scant representation in the literature.
Peñarrocha-Diago & Sanchis-Bielsa 2000
Oral Surg Oral Med Oral Pathol

16. OCULAR COMPLICATIONS OF LOCAL
ANAESTHESIA
 The symptoms develop immediately after the
injection of the anesthetic solution and can
persist for between 1 minute and several
hours, though they only very rarely exceed
the duration of the anesthetic effect.
 Average duration for diplopia was 50 minutes
Peñarrocha-Diago &Sanchis-Bielsa 2000
J. Oral Surg Oral Med Oral Pathol

17. DIPLOPIA
 In case of paralysis of the extrinsic musculature of
the eye (especially the external rectus muscle),
synchronic movement of the eyes becomes
impossible, and diplopia appears.
Peñarrocha-Diago 2000
J. Oral Surg Oral Med Oral Pathol

18. DIPLOPIA
 External rectus muscle palsy, with ocular
abduction difficulties, is the most frequent
finding
Peñarrocha-Diago 2000
J. Oral Surg Oral Med Oral Pathol

19. Symptoms and signs of lateral rectus paralysis
 Symptom:
Diplopia
 Signs:
1- Esotropia
2- Inability to abduct the affected eye
Kelly R. Magliocca et al 2006
J. Oral Surg Oral Med Oral Pathol

20. DIPLOPIA
 Most of the cases reported in the literature
were produced by both lidocaine and
mepivacaine. These complications could also
be caused by articaine, in our opinion,
because of its improved bone diffusion.
Peñarrocha-Diago 2000
J. Oral Surg Oral Med Oral Pathol

21. Hypothesis of ocular complications
 Bony pathways
Direct flow of local anaesthetic
solution through the inferior
orbital fissure from:
1. pterygopalatine fossa
2. infratemporal fossa

22. Hypothesis of ocular complications
 Vascular pathways
 Intra-arterial injection of local
anaesthetic in patients with
uncommon vascular pattern
1. Solution is deposited within the
posterior superior alveolar
artery and forced back into the
maxillary artery and
subsequently into the middle
meningeal artery and then into
the ophthalmic artery

23. Hypothesis of ocular complications
 Vascular pathways
 Intra-arterial injection
2. Solution is deposited within the
inferior alveolar artery and
forced back into the maxillary
artery and subsequently into
the middle meningeal artery
and then into the ophthalmic
artery

24. Hypothesis of ocular complications
 Vascular pathways
 Intra-venous injection
of anaesthetic solution:
1. Solution reaches the
abducent nerve within
the cavernous sinus,
arriving via the
pterygoid plexus

25. Hypothesis of ocular complications
 Vascular pathways
 Intra-venous injection
2. Solution reaches the
inferior ophthalmic vein
via the pterygoid plexus
or its communicating
branches

26. MANAGEMENT OF DIPLOPIA
1. Reassure patients as to the usually transient
nature of these complications
2. Cover the affected eye with a gauze dressing
to protect the cornea and restore normal
monocular vision for the duration of
anaesthesia
Chun-kei Lee 2006
Dental Bulletin

27. MANAGEMENT OF DIPLOPIA
3. The patient should be escorted home by a
responsible adult, since monocular vision is
devoid of distance-judging capability
4. Should the complication last longer than 6
hours, refer the patient to an
ophthalmologist for evaluation
Chun-kei Lee 2006
Dental Bulletin

28. COCLUSION
The physical signs of an inadvertent paresis
of the abducent nerve will no doubt alarm the
unprepared clinician. For the patient’s benefit,
a calm demeanor is imperative. The patient
can be assured of a good prognosis since
cessation of symptoms generally occurs
within a few hours.
Kelly R. Magliocca,2006
J. Oral Surg Oral Med Oral Pathol