Transient loss of power of accommodation in 1 eye following inferior alveolar nerve block: Report of 2 cases

7/27/2019 Transient loss of power of accommodation in 1 eye following inferior alveolar nerve block: Report of 2 cases

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www.cda-adc.ca/jcda December 2006/January 2007, Vol. 72, No. 10 927

Clinicalp r a c t i c E

Transient Loss of Power of Accommodation in1 Eye Following Inferior Alveolar Nerve Block:Report of 2 Cases

Wei Cheong Ngeow, BDS (Mal), FFDRCS Ireland, AM (Mal);Chen Kiong Shim, BDS (Mal), FDSRCS (Eng);Wen Lin Chai, BDS (Mal), FDSRCS (Eng), MDSc (Mal)

ABSTRACT

Unintended intravascular injection from inferior alveolar nerve blocks can result in frus-trating distant complications affecting such structures as the middle ear and eyes. Possible

complications affecting the eyes include blurring of vision, diplopia, mydriasis, palpebral

ptosis and amaurosis (temporary or permanent). In this article, we present a complication

that has been reported only rarely. Two patients developed transient loss of power of

accommodation of the eye resulting in blurred vision after routine inferior alveolar nerve

blocks on the ipsilateral side. Clear vision returned within 1015 minutes after completion

of the blocks. The possible explanation for this phenomenon is accidental injection into

the neurovascular bundle of local anesthetic agents, which were carried via the blood

to the orbital region. This resulted in paralysis of a branch of cranial nerve III, the short

ciliary nerves that innervate the ciliary muscle, which controls accommodation.

Mesh Key Word: anesthesia, dental/adverse effects; diplopia/chemically induced; eye/drug effects J Can Dent Assoc2006; 72(10):92731This article has been peer reviewed.

The administration o local anesthetic is

one o the most common procedures in

dentistry. Hundreds o thousands o anes-

thetic agents are injected daily without serious

complications.1,2

Nevertheless, this procedurecarries the risk o a number o potential com-

plications or the patient, which can be classi-

ed as local, distant or systemic.1,38

Localized complications include separa-

tion o the needle, hyperesthesia or a burning

sensation during injection, persistent post-

injection paresthesia, hematoma orma-

tion that may result in trismus or inection,

sloughing o tissues, postanesthetic intraoral

lesions and sel-inicted sof-tissue trauma

(e.g., cheek biting).410 Hyperesthesia during

injection may be a result o accidental injec-

tion into the neurovascular bundle.

Other nerves may also be aected by intra-

oral local anesthesia injection. Facial nerve

paralysis will occur i cranial nerve (CN) VIIis aected.4 Tere are also reports o trauma to

both lingual nerve and chorda tympani afer

inerior dental injections.3,11,12 Tese accidents

have resulted in permanent alteration o sen-

sation in the lingual nerve, inerior alveolar

nerve or both.11

Structures urther rom the oral cavity,

including the middle ear13 and the eye,14 can

also be aected by intraoral local anesthesia.

Distant complications to the eye have been

reported more requently than middle-ear

Dr. Ngeow

Email:[email protected]

ontactuthor
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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Ngeow

problems. Patients have experienced visual or motor

problems, either rom a posterior superior alveolar in-

ject ion or an inerior alveolar injection.15 Visual prob-

lems include blurring o vision16,17 and amaurosis or

blindness, which can be temporary18 or permanent.1921

Motor problems include mydriasis,14 palpebral ptosis14,18

and diplopia.18,2230 Horner-like maniestations involvingptosis, enophthalmos and miosis o the eye have also

been reported.14

Fortunately, most complications in the eye have been

transient. For example, Rood18 reported a case in which

1.5 mL o lidocaine with epinephrine (1:80,000) was in-

jected into an inerior alveolar nerve. Immediate loss ovision developed in the ipsilatera l eye, along with upper-

eyelid ptosis and medial strabismus, which resulted in

double vision. Te patient also developed ischemia o the

palatal mucosa. However, within 545 minutes, all symp-

toms had disappeared.18 Unortunately, cases o perma-

nent complications have also been reported.1921Systemic complications can result rom accidental

intravascular injection, drug overdose, rapid absorp-tion, delayed biotransormation, slow elimination, vaso-

vagal syncope, allergies and anaphylact ic reaction.4,10,31,32

Among complications involving the orbit, the most

notable are temporary paralysis o the cranial nerves that

govern eye movement: the oculomotor (CN III), trochlear

(CN IV) and abducens (CN VI) nerves.18,2226,29 A litera-

ture search revealed 2 brie mentions o abnormality in

a patients power o accommodation.16,17 Tis eect hasalso been discussed briey in a colour atlas o dental

analgesia.33

Following are 2 case reports o a complication in-

volving only the patients power o accommodation on

the ipsilateral side afer administration o local anesthetic

using the conventional inerior alveolar nerve block

technique.

ase1

A 20-year-old medically t woman was scheduled to

have her lower right third molar removed under local

anesthesia in what was believed to be a routine minor

surgical procedure. Her contralateral lower wisdom tooth

had been removed without complications about 2 yearsearlier.

A conventional inerior alveolar nerve block was being

administered to the right mandible o the semi-reclined

patient when she suddenly elt a sharp shooting pain in

the right side o her ace. At that point, 4.4 mL o 2%

lidocaine with adrenaline (1:80,000), or 2 cartridges, had

been delivered. Te patient stated she had blurry vision

and subsequent examination revealed that power o ac-

commodation was lost in the right eye. She reported onlyblurred oggy vision. Otherwise, she elt ne, although a

little nervous and apprehensive.

Clinical examination revealed that her right eye was

able to distinguish gross items, e.g., number o ngers,but was unable to ocus on small print. Tere was no ac-

companying paresthesia o the lateral parts o the upper

and lower eyelids, nor was there any blanching aroundthe same region. She was not experiencing diplopia.

Afer discussing this unusual complication withthe patient and her mother, it was decided to proceedwith the minor oral surgery and consult an ophthal-

mologist should the patients power o accommodation

not improve afer the eect o the local anesthetic haddisappeared. Te surgical procedure was uneventul.

Te loss o power o accommodation lasted only about

15 minutes, and the patient remained suciently numb inthe dental region or the surgery to be carried out without

pain or additional local anesthetic. Te numbness wore

o about 3 hours afer the initial injection.Unknown to the surgeons, the patient drove her-

sel home (a 10-minute journey) with the consent oher mother. Te authors only learned about this whenquerying her about the details o her complication or

this article. At the time, she elt that her visual acuity had

improved suciently to allow her to drive.

ase2

During a practice exercise at the aculty o dent-istry o the University o Malaya, a healthy 21-year-old

dental student was given a conventional inerior nerve

block in the lef mandible that resulted in complete anes-thesia o the inerior alveolar and lingual nerves. One

o the authors (WCN) was demonstrating the standardtechnique when, on completion o the block, the studentcomplained o not being able to see clearly with her

lef eye. She was reassured that this eect was transient

and, as predicated, her power o accommodation re-turned to normal 10 minutes later. Hal an hour later, her

ellow students perormed another conventional inerior

alveolar nerve block on the opposite side without anyurther complications.

iscussion

Visual acuity reers to the clarity o ones vision; it is a

measure o how well a person sees. Tis clarity depends onthe power o accommodation o the eye. Accommodationis the process that changes the ocal length o the eyes

lens by altering its curvature. An increase in curvature

ocuses the eye or near vision, creating a sharp imageon the retina, which is interpreted as a clear object by

the person concerned. Tis action depends on the high

elasticity o the lens capsule and contraction o the ciliarymuscle, which is innervated by the short ciliary nerves.34

Te short ciliary nerves are the postganglionic bres

o the ciliary ganglion. Te ciliary ganglion is aboutthe size o the head o a pin, quadrangular and at-


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Loss of Accommodation

tened; it is reddish-grey in colour and situ-ated in the posterior part o the orbit, close tothe apex o the orbit between the optic nerveand the lateral rectus muscle.33 It generallylies on the outer side o the ophthalmic artery(Fig. 1).34 CN III (occulomotor) provides para-

sympathetic preganglionic bres to this gan-glion.35 Another nerve, the nasociliary nerve,also provides a communicating branch to theciliary ganglion. However, it passes throughthe ganglion without interruption and pro-vides sensation to the eyeball. 35

Te branches o distribution o the shortciliary nerves are delicate laments, 610 innumber. Tey arise in 2 bundles rom thesuperior and inerior corners o the oreparto the ganglion.34 Tey run orward with theciliary arteries in a wavy course, one set above

and the other below the optic nerve, and areaccompanied by the long ciliary nerves romthe nasal branch o the ophthalmic nerve. Teypierce the sclerotic plate behind the globe, passorward in delicate grooves on its inner sur-ace and are distributed to the ciliary muscle,iris and cornea.34

Te loss o power o accommodation isa consequence o the paralysis o the ciliarymuscle either due to injury or anesthesia o CN III. Whencomplete, paralysis o CN III results in ptosis, externalstrabismus, di latation o the pupil and loss o power o ac-commodation as the sphincter pupillae, the ciliary muscleand the internal rectus are paralyzed.34 Occasionally par-alysis may aect only a part o the nerve. Tus, there maybe internal strabismus rom spasm o the internal rectus;accommodation or near objects only rom spasm o theciliary muscle; or miosis (contraction o the pupil) romirritation o the sphincter o the pupil. 34 Similar par-tial paralysis or, more specically, paralysis o the shortciliary nerves may have occurred in both cases reportedhere.

In reporting several cases involving transient amaur-osis and diplopia, Blaxter and Britten36 postulated thatan intra-arterial injection o the inerior alveolar artery

had occurred, with the anesthetic agent travelling tothe internal maxillary artery, the middle meningeal ar-tery and, nally, the lacrimal and ophthalmic arteries.Goldenberg23,24 reported a similar case ollowing a man-dibular injection, and traced the anesthetic to the lacrimalartery.Rood18 also described a possible arterial route ordiusion o a vasoconstrictive agent rom the alveolarartery to the internal maxillary and middle meningealarteries and, nally, rom the lacrimal to the ophthalmicartery by way o anastomotic connections.

Te maxillary artery has been shown to have a highlyvariable relation to the branches o the mandibular

neurovascular bundle37 and enormous individual varia-tion in its topography, diameter, size o the downwardloop and its position relative to the mandibular oramen.38Te middle meningeal artery can arise as the secondmajor branch o the maxillary artery. 37 Moreover, in 4%o patients, the ophthalmic artery arises not rom theinternal carotid but rom the middle meningeal arteryollowing direct ow rom the external carotid artery.39Tese variations have been postulated to contribute toocular complications ollowing intraoral local anestheticinjections. Other authors have proposed the existence ovascular malormations or anomalies that may producethe retrograde anesthetic diusion phenomenon.30,40

I another block administered to our patient 1 on thesame side produced the same loss o visual acuity, thenthe cause could most certainly be attributed to anatomic

variation in the patient.Te requency o positive aspirations in which injec-

tions were given via the conventional inerior alveolarinjection technique has been reported to be 7.9%.13 Tus,based on the case studies above and the act that 1 pa-tient (case 1) experienced a sharp shooting pain duringthe injection, we would like to postulate that due tothe constant shifing o position o the needle duringadministration o the block, the needle penetrated theneurovascular bundle. Te surgeon (WCN) may havestarted depositing the local anesthetic agent when thepatient screamed in pain, and the needle was withdrawn

Figure1:Anatomic relation between the mandible and the orbit.This illustration shows the potential route of dissemination oflocal anesthetic from the mandible to the short ciliary nerves thatinnervate the ciliary muscle.


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Ngeow

rom the painul site. However a tiny bolus o the localanesthetic might have been inadvertently deposited intothe artery beore withdrawal. Tis bolus may have oundits way into the maxillary artery and, subsequently, beencarried to the orbital area, via any o the mechanismsdescribed above.16,2327,30,3640 We suspect that the amount

was only sucient to anesthetize the short ciliary nervesor a ew minutes, but not enough to bring about suchsigns and symptoms as transient dizziness, paralysis othe eye muscles and anesthesia o the lateral parts o theupper and lower lips.16 Both our patients remained su-ciently anesthetized or more than 2 hours, comparedwith Goldenbergs case, where the patient was not an-esthetized although exhibiting signs and symptoms ovision problems.23,24

Data obtained by contrast radiography and hemo-dynamic and electroencephalographic studies in rhesusmonkeys indicated that carotid blood ow is reversible.41

Results showed that even small amounts o local anes-thetic agents, when injected inadvertently into a brancho the external carotid artery, may enter the cerebralcirculation, most likely through retrograde ow into thecommon and then internal carotid arteries. Tus, an-other possible mechanism to explain the loss o power oaccommodation is the retrograde ow o local anestheticagent to the cavernous sinus area. Any cerebral diseasecausing pressure on the cavernous sinus will result inparalysis o the CN III34 due to their close proximity.In this case, rather than cerebral disease, the cause oparalysis o the nerve concerned was deposition o localanesthetic via retrograde ow.

Although this complication is transient, it is mostcertainly o concern to both patients and dental surgeons.An aspirating syringe should be used wherever possibleto avoid intra-arterial injection. Tis case also serves as acautionary tale or all dental surgeons, as patients shouldbe warned o the risks involved.

onclusions

Unintended intravascular injections rom inerior al-veolar nerve blocks result in rustrating complications:locally, distally or systemically. It is imperative that dentalsurgeons diagnose complications and manage them ap-

propriately. Prompt diagnosis and reassurance usuallycalm the patient. In cases where visual acuity is aected,patients should be advised against dangerous tasks likedriving or using sharp instruments, at least until the localanesthetic eect has worn o. a

THE AUTHORS

Dr. Ngeowis lecturer in the aculty o dentistry, University oMalaya, Kuala Lumpur.

Dr. Shim is a dental specialist in an oral surgery clinic, MiriGeneral Hospital, Ministry o Health Malaysia.

Dr. Chaiis a lecturer in the aculty o dentistry, University oMalaya, Kuala Lumpur.

Correspondence to: Dr. W.C. Ngeow, Department o Oral andMaxilloac ial Surgery, Faculty o Denti stry, Univers ity o Malaya, 50603Kuala Lumpur, Malaysia.

Te authors have no declared fnancial interests.

References1. Lustig JP, Zusman SP. Immediate complications of local anesthetic adminis-tered to 1,007 consecutive patients.J Am Dent Assoc1999; 130(4):4969.

2. Cawson RA, Curson I, Whittington DR. The hazards of dental local anaes-thetics. Br Dent J1983; 154(8):2538.

3. Paxton MC, Hadley JN, Hadley MN, Edwards RC, Harrison SJ. Chorda tym-pani nerve injury following inferior alveolar injection: a review of two cases.

J Am Dent As soc1994; 125(7):10036.4. Malamed SF. Handbook of local anesthesia. 4th ed. St. Louis: Mosby;1997. p. 51, 132, 193, 193219, 24686.

5. Meechan JG, Rood JP. Adverse effects of dental local anaesthesia. DentUpdate 1997; 24(8):3158.

6. Haas DA. Localized complications from local anesthesia. J Calif Dent Assoc1998; 26(9):67782.

7. Stacy GC, Hajjar G. Barbed needle and inexplicable paresthesia andtrismus after dental regional anesthesia. Oral Surg Oral Med Oral Pathol1994; 77(6):5858.

8. Flaitz CM, Felefli S. Complications of an unrecognized cheek biting habitfollowing a dental visit. Pediatr Dent2000; 22(6):5112.

9. Faura-Sole M, Sanchez-Garces MA, Berini-Aytes L, Gay-Escoda C. Brokenanesthetic injection needles: report of 5 cases. Quintessence Int 1999;30(7):4615.

10. Laskin DM. Diagnosis and treatment of complications associated withlocal anaesthesia. Int Dent J1984; 34(4):2327.

11. Harn SD, Durham TM. Incidence of lingual nerve trauma and postinjec-tion complications in conventional mandibular block anesthesia. J Am Dent

Assoc1990; 121(4):51923.

12. Pogrel MA, Thamby S. Permanent nerve involvement resulting from in-ferior alveolar nerve blocks. J Am Dent Assoc2000; 131(7):9017.

13. Brodsky CD, Dower JS Jr. Middle ear problems after a Gow-Gates injec-tion. J Am Dent Assoc 2001; 132(10):14204.

14. Penarrocha-Diago M, Sanchis-Bielsa JM. Ophthalmologic complicationsafter intraoral local anesthesia with articaine. Oral Surg Oral Med Oral PatholOral Radiol Endod2000; 90(1):214

15. Cooley RL, Cottingham AJ Jr. Ocular complications from local anestheticinjections. Gen Dent1979; 27(4):403.

16. Webber B, Orlansky H, Lipton C, Stevens M. Complications of an intra-arterial injection from an inferior alveolar nerve block. J Am Dent Assoc2001; 132(12):17024.

17. Cooper JC. Deviation of eye and transient blurring of vision after mandi-

bular nerve anesthesia: report of a case.J Oral Surg Anesth Hosp Dent Ser v1962; 20:1512.

18. Rood J. Ocular complication of inferior dental nerve block. A case report.Br Dent J1972; 132(1):234.

19. De Keyzer K, Tassignon MJ. [Case report: acute unilateral loss of visual[Case report: acute unilateral loss of visualacuity after a visit to the dentist: an unusual complication after the use ofan anesthetic combined with adrenaline.] Article in French. Rev Belge MedDent2004; 59:303.

20. Rishiraj B, Epstein JB, Fine D, Nabi S, Wade NK. Permanent vision loss inone eye following administration of local anesthesia for a dental extraction.Int J Oral Maxillofac Surg 2005; 34(2):2203.

21. Tommazzoli-Gerosa L, Marchini G, Monaco A. Amaurosis and atrophyof the optic ner ve: an unusual complication of mandibular-nerve anesthesia.

Ann Ophthalmol1988; 20(5):1701.

22. Leopard PJ. Diplopia following injection of a local anaesthetic. Dent PractDent Rec1971; 22(3):924.


5/5


Loss of Accommodation

23. Goldenberg AS. Transient diplopia as a result of block injections.Mandibular and posterior superior alveolar. N Y State Dent J 1997;63(5):2931.

24. Goldenberg AS. Transient dipoplia from a posterior alveolar injection.J Endod1990; 16(11):5501.

25. Goldenberg AS. Diplopia resulting from a mandibular injection. J Endod1983; 9(6):2612.

26. Marinho RO. Abducent nerve palsy following dental local analgesia. Br Dent J1995; 179(2):6970.

27. Koumoura F, Papageorgiou G. Diplopia as a complication of local anes-thesia: a case report. Quintessence Int2001; 32(3):2324.

28. Kronman JH, Kabani S. The neuronal basis for diplopia following localanesthetic injections. Oral Surg Oral Med Oral Pathol1984; 58(5):5334.

29. Petrelli EA, Steller RE. Medial rectus muscle palsy after dental anesthesia.Am J Ophthalmol1980; 90(3):4224.

30. Hyams SW. Oculomotor palsy following dental anesthesia. ArchOphthalmol1976; 94(8) :12812.

31. Ogunsalu CO. Anaphylactic reaction following administration of ligno-caine hydrochloride infiltration. Case report.Aust Dent J1998; 43(3):1701.

32. Hidding J, Khoury F. [General complications in dental local anesthesia.]Article in German. Dtsch Zahnarztlz1991; 46(12):8346.

33. Roberts GJ, Rosenbaum NL. A colour atlas of dental analgesia and seda-tion. England: Wolfe Publishing; 1991. p. 67.

34. Pickering T, Howden R. Grays anatomy, descriptive and surgical.15th ed. London: Chancellor Press; 1985. p. 7039, 80530.

35. Snell RS. Clinical anatomy for medical students. 3rd ed. Boston: LittleBrown & Co.; 1986. p. 8257.

36. Blaxter P, Britten MJ. Transient amaurosis after mandibular nerve block.Br Med J1967; 1(5541):681.

37. Pretterklieber ML, Skopakoff C, Mayr R. The human maxillary artery rein-vestigated: I. Topographical relations in the infratemporal fossa. Acta Anat(Basel) 1991; 142(4):2817.

38. Roda RS, Blanton PL. The anatomy of local anesthesia. Quintessence Int1994; 25(1):2738.

39. Singh S, Dass R. The central artery of the retina. I. Origin and course .Br J Ophthalmol1960; 44:193212.

40. Bandres A, Penarocha M, Sanchis JM. [Complicaciones de la anestesiadental.] Anales Odontoestomatol1997; 3:8795.

41. Aldrete JA, Narang R, Sada T, Tan Liem S, Miller GP. Reverse carotid flowReverse carotid flow a possible explanation for some reactions to local anesthetic. J Am Dent

Assoc1977; 94(6):11425.

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Transient loss of power of accommodation in 1 eye following inferior alveolar nerve block: Report of 2 cases