Prolonged Diplopia Following a Mandibular Block. Injection. Pieter van der Biji, BSc(Hons), BChD, PhD,* and Trevor L.Lamb, BDSt. *Department of Oral ...
CASE REPORT
Prolonged Diplopia
Following
a
Mandibular
Block
Injection Pieter van der Biji, BSc(Hons), BChD, PhD,* and Trevor L. Lamb, BDSt *Department of Oral Medicine and Periodontics, Faculty of Dentistry, University of Stellenbosch, Tygerberg, South Africa; t20 Bracken Gardens, Medical and Dental Centre, Brackenhurst, Alberton, South Africa
Although large numbers of local anesthetic injections Jid are given annually in dental practice worldwide, ophthalmic complications associated with these procedures rarely ensue. However, transient oculomotor palsies and temporary as well as permanent loss of vision following mandibular and maxillary nerve blocks have been reported in the literature.'-'0 A number of possible mechanisms have been advanced to explain the pathogenesis of these complications. These range from intraarterial deposition of anesthetic into the inferior alveolar artery,1-4 to direct injection of the drug into the orbit through the inferior orbital fissure.56"' While many of these mechanisms may at least partially explain the complications involved, the authors of the most comprehensive study to date on the topic consider none of these to be perfectly satisfactory and unequivocal.'2 Furthermore, it is interesting to note that of the 27 cases reviewed, the three youngest individuals were 16 yr old and only four in total were younger than 18. We present a case in which transient diplopia developed in a young teenage girl following a mandibular local anesthetic block.
molar. The injection was given slowly while the patient lay supine in the dental chair. No aspiration was performed before depositing the anesthetic. Following administration of the anesthetic, the patient was returned to the sitting position for the dental anesthetic to take effect. A period of some 10 min was allowed for this purpose. No adverse effects-eg, blanching of the skin over the maxilla, signs of dizziness, or any other complaints from the patient-were noted during or immediately after the injection procedure. The restorative procedure was completed uneventfully in about 20 min and the patient returned home in the care of her mother. About 4 hr later, the patient complained of blurred/double vision and occasional light flashes in her left eye, but was othervise symptomless. Although the binocular diplopia did not progress over the next hour or so, the mother consulted one of the authors (PvdB). The patient still felt well and there were no accompanying signs and symptoms, such as numbness of the eyebrow or maxillary skin, nor was there any loss of motor function of the eyelids. Both pupils were circular and equal in size, and the full range of abduction/adduction eye motions were possible. In view of the foregoing, it was decided to manage the patient conservatively. The mother was advised to observe her daughter carefully for the next 24 hr and to report any further visual deterioration or other symptoms immediately. The followAng morning, after an uneventful and restful night, the patient's vision was still blurred and remained so until the afternoon, ie, about 20 hr later. At this stage, her vision gradually started to improve and had returned to normal by the end of the afternoon (24 hr after the injection). Subsequent to this event, the patient has not required any local anesthetic injections for dental or other procedures.
CASE REPORT A 14-yr-old Caucasian girl reported to her private dentist for routine restorative treatment late one afternoon. She had a history of allergy to penicillin and sulfonamides, but was otherwise healthy and had previously never required any dental procedures under local anesthesia. She was given a left inferior alveolar nerve block with one cartridge (1.8 ml) of Xylotox E 80 A (lidocaine 2% with 1: 80,000 epinephrine) for the placement of an occlusobuccal amalgam restoration on the lower left first
DISCUSSION
Received June 20, 1995; accepted for publication February 6, 1996. Address correspondence to Dr. Pieter van der Bijl, Faculty of Dentistry, Private Bag Xl, 7505 Tygerberg, Republic of South Africa. Anesth Prog 43:116-117 1996 © 1996 by the American Dental Society of Anesthesiology
The majority of ocular complications of dental anesthesia reported by various authors develop within minutes ISSN 0003-3006/96/$9.50 SSDI 0003-3006(96)
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van der Bijl and Lamb
Anesth Prog 43:116-117 1996
following injection (mean ± SD: 8 ± 10 min), are of a transient nature, and usually resolve without sequelae within 5 hr (mean ± SD: 1.2 ± 1.5 hr).4'8"2 Three cases have been reported in which damage was permanent with deficits still present many years after the event5"13"14; in two other cases, fat embolism of the central retinal artery was involved.15 The most commonly suggested explanation for oculomotor disturbances after injection of dental local anesthetics is that of inadvertent deposition of some of the drug into the inferior alveolar artery, mandibular canal, or posterior superior alveolar artery.8 By reverse flow, the anesthetic agent then reaches the internal maxillary and middle meningeal arteries, the orbital branch of the latter anastomosing with the lacrimal branch of the ophthalmic artery. Other explanations include those based on spread by direct extension via venous, lymphatic, or neural routes.8"2 These and any other explanation that relates the ocular complications to the vascular, lymphatic, or nerve route theory as a result of the pharmacological action of the local anesthetic may account for at least some of the observed rapid onset visual disturbances lasting less than 5 hr. In the case presented above, the diplopia had a relatively slow onset, ie, 4 hr, and lasted for 24 hr. Four other cases have been reported in which visual disturbances lasted for 96 hr, with only one patient recovering without further treatment.'2 In two of these cases, onset of symptoms occurred immediately after injection, while in the other two there was a latent phase of 48 hr. These cases, including the present one, are not adequately explained by the vascular, lymphatic, or neural route theories. Furthermore, it is interesting to note that the patient in the present case report was only 14 yr old. This is, to our knowledge, the youngest patient in which ocular complications due to dental local anesthesia have been reported. It is not clear whether these complications occur less frequently in young patients or are simply not reported. The clinical consequences of diplopia as a result of dental local anesthesia are usually minor. It has been suggested that a patient needs to be reassured as to the usually transient nature of the diplopia and that the cornea of the affected eye should be protected with an eye pad; the patient should, of course, be escorted home by a responsible adult.10 Generally, however, should patients suffer ocular complications lasting longer than 6 hr following dental anesthesia, it would seem prudent to
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refer them without further delay to an ophthalmologist for evaluation. This was not deemed necessary in the present case because retinal/optic nerve ischemia was not suspected. Although the adverse ocular effects following administration of local anesthetic injections in dental practice are almost always transient, a few cases have been reported in which permanent loss of vision resulted. For this reason, it is important that dentists be aware of these complications and their proper management. REFERENCES 1. Cooper JC: Deviation of eye and transient blurring of vision after mandibular nerve anesthesia. J Oral Surg 1962;20: 151-152. 2. Blaxter PL, Britten MJA: Transient amaurosis after mandibular nerve block. Br Med J 1967;1:681. 3. Rood JP: Ocular complication of inferior dental nerve block. Br Dent J 1972;132:23-24. 4. Goldenberg AS: Diplopia resulting from a mandibular injection. J Endodon 1983;9:261-262. 5. Hyams SW: Oculomotor palsy following dental anesthesia. Arch Ophthalmol 1976;94:1281-1282. 6. Petrelli EA, Steller RE: Medial rectus muscle palsy after dental anesthesia. Am J Ophthalmol 1980;90:422-424. 7. Goldberg RT: Vertical pendular nystagmus in chronic myositis of medial and lateral rectus. Ann Ophthalmol 1978;10: 1697-1702. 8. Goldenberg AS: Transient diplopia from a posterior alveolar injection. J Endod 1990;16:550-551. 9. McNicholas S, Torabinejad M: Esotropia following posterior superior alveolar nerve block. J Calif Dent Assoc 1992;34:33-34. 10. Sved AM, Wong JD, Donkor P, et al: Complications associated with maxillary nerve block anaesthesia via the greater palatine canal. Aust Dent J 1992;36:340-345. 11. Himmelfarb R: Interpreting the cause of diplopia after dental injection. Arch Ophthalmol 1980;98:575. 12. Madrid C, Duran D, Gante P, Reynes P: Accidents ophthalmiques des anesthesies loco-regionales en odontologie: aspects cliniques, voies anatomiques. Actual Odontostomatol (Paris) 1990;44:271-283. 13. Walsh FB, Hoyt WF: Craniocerebral trauma, hypoxia, and injuries by other physical agents: involvements of the visual and ocular motor systems. In: Clinical Neuro-Ophthalmology, 3rd ed., Volume 3. Baltimore, MD, Williams & Wilkins Co., 1969;2501-2502. 14. O'Connor M, Eustace P: Tonic pupil and lateral rectus palsy following dental anesthesia. Neuro-Ophthalmology 1983;3:205-208. 15. Sokolic P: Clinical contribution to retinal tele-trauma. Med Arh 1960;14:37-43.
