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Blindness following fracture of the zygomatic bone
British Journal of Oral and Maxillofacial Surgery ( 1986) 24, 12-16 0 1986 The British Association of Oral and Maxillofacial Surgeons
BLINDNESS
FOLLOWING G.
D. WOOD,
FRACTURE B.D.S.,
Regional Oral and Maxillofacial
M.Sc.,
OF THE M.D.S.,
ZYGOMATIC
BONE
F.D.S.K.C.P.S.
Unit. Royal Liverpool Hospital, Prescot Street, Liverpool.
Summary. Two cases of blindness following fracture of a zygomatic bone. with disruption of the optic canal are reported. The importance of excluding optic canal disruption where blindness results subsequent to fracture or surgery to the orbit in the presence of certain features of retrobulbar haemorrhage is emphasised.
Introduction Blindness attributed to retrobulbar haemorrhage has occurred following ocular trauma (Huang et al., 1977; Babajews & Williams, 1986), malar fracture reduction (Gordon & Macrae, 1950; Penn 8( Epstein, 1953; Gordon, 1957; Magoon, 1963; 1968; Ord, 1981), orbital floor repair Rowe, 1967; Varley & Holt-Wilson, (Nicholson & Guzak, 1971), orbital surgery (Long & Ellis, 1971; Ord, 1981) and blepharoplasty (De Mere et al., 1974; Hueston & Heinze, 1974; Putterman, 1975; Heinze & Hueston, 1978). Ord (1981) reports the incidence of post-operative retrobulbar haemorrhage with visual loss to be 0.3% of malar fractures. Retrobulbar haemorrhage may follow the administration of retrobulbar anaesthetics for ophthalmic surgical procedures. Conservative treatment of the condition with no loss of vision has been reported (Huang et al., 1977; Ord, 1981). The clinical features of retrobulbar haemorrhage are pain, proptosis, a tense globe with a dilating pupil, ophthalmoplegia, sub-conjunctival haemorrhage. swelling of the eyelids and intra-orbital tissues. Hippocrates was the first to record the association of facial trauma with blindness (Manfredi et al., 1981) but Berlin (1881) undertook the first scientific investigation and noted that facial injuries could result in a fracture of the optic canal with secondary injury to the optic nerve. Case Reports
Case 1 A 30 year-old Caucasian woman attended Arrowe Park Hospital, Wirral, following a fall downstairs while sleep walking. She was rendered unconscious but by the time of admission was conscious, alert and orientated in time. space and person. Radiographic and clinical examination demonstrated a displaced fracture of the right zygomatic bone in addition to fractures of the proximal metacarpophalangeal joint of the left hand and a Colles’ fracture of the right wrist. She was admitted to hospital for observation of her head injury and for subsequent treatment of her fractures. 6 h after injury she complained that she had no vision from the right eye and was examined immediately by a consultant ophthalmologist who found no direct right or left consensual pupil response to light but almost normal eye movements. Proptosis was minimal and the right optic disc appeared (Received
28 March
19X5; accepted
12
17 August
19X5)
BLINDNESS
FOLLOWING
FRACTURE
Fig. Figul re l-Radiograph
of orbital
apex of Case
I
OF
THE
ZYGOMATIC
BONE
13
I
showing di sconl :inuity (arrowed)
of optic foramcn.
oedematous. Further radiographic examination (Fig. 1) demonstrated a fracture with disruption of the right optic canal. Surgery was undertaken without delay to align the fractured zygomatic bone. This was accomplished using fronto-zygomatic and infra-orbital wires. The floor of the orbit was explored and found to be intact except for a single displaced fracture. A drain was inserted to decompress the orbital floor. Immediately after surgery the patient claimed she was able to see from the right eye and the direct and consensual pupil responses to light were slow but present. However, the following morning and to date, the patient remains blind in the right eye. Further radiographic examination the next day demonstrated no reduction of the fracture of the right optic canal. Case 2 A 22 year-old Caucasian male was referred to the Royal Liverpool Hospital following a road traffic accident. He had been rendered unconscious and sustained fractures of the left wrist, frontal bone and left and right supraorbital rims with disruption of the left optic canal (Fig. 2); there was a fracture of the left zygomatic bone in addition to a Le Fort II fracture and body fractures of the mandible. There was no proptosis or ophthalmoplegia of the left eye and no direct but a reduced right consensual response to light. The patient had a persistent cerebrospinal fluid leak which subsequently required neurosurgical repair. The patient remains blind in the left eye.
14
BRITISH
JOURNAL
OF
ORAL
&
Fig. Figure
2-Disruption
MAXILLOFACIAL
SURGERY
2
of optic
canal
(Case
2)
Discussion
Some previously reported cases of blindness associated with fractures or surgery to the zygomatic bone where blindness was accredited solely to a retrobulbar haemorrhage could possibly be due to fracture of the optic canal. Disruption of the optic canal, in addition to retrobulbar haemorrhage, may have occurred, and must be excluded when injuries of the orbital region have resulted in loss of vision. Postmortem investigation has demonstrated that injury to the optic nerve resulting from optic canal fractures is rarely the result of osseous compression, laceration of the nerve or haemorrhage into the nerve itself. More often haemorrhage into the optic sheath or contusion of the nerve results in oedema and compression (Pringle, 1922; Hughes, 1962; Walsh, 1969; Manfredi et al., 1981). The injury could lead to secondary compression of the vascular supply to the nerve where the nerve sheath is fixed to its bony surroundings. The ophthalmoscopic findings in reported cases of blindness attributed to retrobulbar haemorrhage do not always demonstrate the classical signs of posterior polar oedema and a cherry red macular spot of central retinal artery occlusion (Ord, 1981). Varley et al. (1968) and Nicholson and Guzak, (1971) demonstrated the signs, and Heinze and Hueston (1978), reviewing cases of blindness after blepharoplasty, state that these signs had not been reported. Radiographic demonstration of the fractures can be difficult. Optic canal views and tomograms of the orbit can demonstrate the fractures as in the present cases but these techniques can be unreliable (Turner, 1943; Hooper, 1951; Ramsey, 1979; Manfredi et al., 1981). Computerized tomographic scan has been used to demonstrate optic canal fractures (Manfredi et al., 19Sl), and is most useful when blindness has resulted or when spheno-ethmoidal sinus haemorrhage is seen on plain radiography. However, technical factors in CT scanning may prevent
BLINDNESS
FOLLOWING
FRACTURE
OF
THE
ZYGOMATIC
BONE
15
demonstration of the fracture (thickness of cut and plane) if a ‘state of the art’ scanner is not available. A CT scan however, will allow good resolution of soft tissues or haematoma that would not be evident from plain radiography. Blindness subsequent to orbital trauma or surgery may result from central retinal artery occlusion, a fracture disrupting the optic canal or from retrobulbar haemorrhage which may cause anterior optic nerve head ischaemia as described by Ord (1981). Orbital decompression alone in cases where the optic canal is grossly disrupted will be inadequate (Manfredi et al., 1981). However, Fukado (1973) reported the results of 400 transethmoidal decompressions of the optic nerve. The technique involved a medial approach under local anaesthesia to the anterior wall of the ethmoid sinus, which is removed to gain access to the optic canal. The inner wall of the optic canal is perforated, taking care that the periosteum and the dural sheath of the optic nerve are spared. However the paper does not report a restoration of vision following the procedure, and the technique remains to be tested when acute blindness results from disruption of the optic canal. Decompression of the optic nerve and/or realignment of the optic canal at the site of the fracture with inspection of the optic nerve cannot seriously be contemplated, as such a procedure would require an intra-cranial approach and the possible complications of such surgery are not acceptable (Foy, 1984). The use of intravenous or intra-muscular acetazolamide 500 mg, hydrocortisone 100 mg I.V. or Mannitol2OX rapid infusion (Ord, 1981) as the medical treatments of retrobulbar haemorrhage remain to be tested in the management of blindness due to a disrupted optic canal. Blindness in the present cases has resulted from fracture of the optic canal causing either direct damage to the optic nerve and/or occlusion of the ophthalmic artery. The patients did not exhibit all the features of retrobulbar haemorrhage. which led to the suspicion and discovery of fracture of the optic canal. It may be that a thick orbital bony floor (as in Case 1) may be significant in resulting in disruption of the optic canal rather than comminution of the orbital floor. The interceptive surgery and medical measures undertaken for the patients have not restored sight. In the first case this may have been the result of delay in surgery which was 10 hours, and more speedy action may possibly have had a more satisfactory outcome. Acknowledgements I would like to thank Mr Roger Ainley, Consultant Ophthalmologist at Arrowe Park Hospital, for his help in the management of the first case and for assistance in the preparation of this paper.
References Babajews, A. & Williams. J. (1986). Blindness after trauma insufficient to cause bony injury. British Journal of Oral and Maxillofacial Surgeq, 24, 7. Berlin, R. (1881). Injuries to the optic nerve and ophthalmic artery from fracture of the optic canal. Transactions of the Seventh Inlernational Medical Congress, Vol. 3. London: Kolckmann. p. 115. De Mere, H., Wood, T. & Austin, W. (1974). Eye complications with blepharoplasty and other eyelid surgery. Plastic and Reconstructive Surgery, 53, 634. Foy, P. M. (1984). Personal Communication. Fukado, Y. (1975). Results in 400 surgical cases of decompression of the optic nerve. Modern Problems in Ophthalmology, 14, 474. Gordon, S. & Macrae, H. (1950). Monocular blindness as a complication of a malar fracture. Plastic and Reconstructive Surgery, 6, 228.
16
BRITISH
JOURNAL
OF
ORAL
&
MAXILLOPACIAL
SURGERY
Gordon. S. (lYS7). Malar fracture: intra-orbital haemorrhage during open reduction. Plasric and Reconstrucrive Surgery, 20, 65. Heinze, J. B. & Hueston, J. T. (1978). Blindness after blepharoplasty; mechanism and early reversal. Plastic and Reconstructive Surgerv, 61, 347. Hooper, R. S. (19.51). Orbital comphcations of head injury. Briush Journal of Surgery, 39, 126. Huang. T. T., Horwitz & Lewis, S. R. (1977). Retrobulbar haemorrhage. Plastic und Reconstructive Surgery, 59, 39. Hueston. J. T. & Heinze, J. B. (1974). Successful early relief of blindness occurring after blepharoplasty. Plastic and Reconstrucrive Surgery, 53, 588. Hughes. B. (1962). Indirect injury to the optic nerves and chiasma. Rullerin of the John.v Hopkins Hospital, 111, 98. Long, J. C. & Ellis, P. P. (1971). Total unilateral visual loss following orbital surgery. Americun Journal of Ophthalmology, 71, 218. Magoon, R. C. (1963). Orbital fracture and retrobulbar haemorrhage. American Journal of Ophthalmology. 55, 370. Manfredi, S. J.. Raji, M. R., Sprinkle, P. M.. Weinstein, G. W., Minardi, L. N. & Swanson, T. J. (1981). Computerised tomographic scan findings in facial fractures associated with blindness. Plastic and Reconstructive Surgery, 68. 479. Nicholson. D. H. & Guzak, S. U. Jr. (1971). Visual loss complicating repair of orbital floor fractures. Archives of Ophthalmology, 86, 369. Ord, R. A. (1981). Post-operative retrobulbar haemorrhagc and blindness complicating trauma surgery. British Journal of Oral Surgery, 19, 202. Penn, J. & Epstein, E. (1953). Complication following late manipulation of impacted fracture of malar. British Journal of Plastic Surgery, 6, 65. Pringle, H. J. (1922). Atrophy of the optic nerve following diffused violence to the skull. British Medical Journal. 2, 1156. Putterman, A. H. (1975). Temporary blindness after blepharoplasty. American Journal of Ophthalmology, 80, 1081. Ramsey. J. H. (197Y). Optic nerve injury in fracture of the canal. British Journal of Ophthalmology,63, 607. Rowe, N. L. (1967). Cited by Varley, E. W. B.. Holt-Wilson, A. D. Acute retinal arterial occlusion following reduction of a fractured zygoma and its successful treatment. Turner. J. W. A. (1943). Indirect iniuries of the optic nerve. Bruin. 66. 140 Varley. E. W. B., Holt-Wilson, A. D.‘(lYnX). Acute retinal arterial occlusion following reduction of a British Journal of Orul Surgery, 6, 31. fractured zygoma and its successful treatment. Walsh, F. B. B Foyt. W. F. (1969). Clinical Neuro-Ophthalmology. Vol. 3, Third Ed. Baltimore: Williams and Wilkins. p. 2362.
BLINDNESS
FOLLOWING G.
D. WOOD,
FRACTURE B.D.S.,
Regional Oral and Maxillofacial
M.Sc.,
OF THE M.D.S.,
ZYGOMATIC
BONE
F.D.S.K.C.P.S.
Unit. Royal Liverpool Hospital, Prescot Street, Liverpool.
Summary. Two cases of blindness following fracture of a zygomatic bone. with disruption of the optic canal are reported. The importance of excluding optic canal disruption where blindness results subsequent to fracture or surgery to the orbit in the presence of certain features of retrobulbar haemorrhage is emphasised.
Introduction Blindness attributed to retrobulbar haemorrhage has occurred following ocular trauma (Huang et al., 1977; Babajews & Williams, 1986), malar fracture reduction (Gordon & Macrae, 1950; Penn 8( Epstein, 1953; Gordon, 1957; Magoon, 1963; 1968; Ord, 1981), orbital floor repair Rowe, 1967; Varley & Holt-Wilson, (Nicholson & Guzak, 1971), orbital surgery (Long & Ellis, 1971; Ord, 1981) and blepharoplasty (De Mere et al., 1974; Hueston & Heinze, 1974; Putterman, 1975; Heinze & Hueston, 1978). Ord (1981) reports the incidence of post-operative retrobulbar haemorrhage with visual loss to be 0.3% of malar fractures. Retrobulbar haemorrhage may follow the administration of retrobulbar anaesthetics for ophthalmic surgical procedures. Conservative treatment of the condition with no loss of vision has been reported (Huang et al., 1977; Ord, 1981). The clinical features of retrobulbar haemorrhage are pain, proptosis, a tense globe with a dilating pupil, ophthalmoplegia, sub-conjunctival haemorrhage. swelling of the eyelids and intra-orbital tissues. Hippocrates was the first to record the association of facial trauma with blindness (Manfredi et al., 1981) but Berlin (1881) undertook the first scientific investigation and noted that facial injuries could result in a fracture of the optic canal with secondary injury to the optic nerve. Case Reports
Case 1 A 30 year-old Caucasian woman attended Arrowe Park Hospital, Wirral, following a fall downstairs while sleep walking. She was rendered unconscious but by the time of admission was conscious, alert and orientated in time. space and person. Radiographic and clinical examination demonstrated a displaced fracture of the right zygomatic bone in addition to fractures of the proximal metacarpophalangeal joint of the left hand and a Colles’ fracture of the right wrist. She was admitted to hospital for observation of her head injury and for subsequent treatment of her fractures. 6 h after injury she complained that she had no vision from the right eye and was examined immediately by a consultant ophthalmologist who found no direct right or left consensual pupil response to light but almost normal eye movements. Proptosis was minimal and the right optic disc appeared (Received
28 March
19X5; accepted
12
17 August
19X5)
BLINDNESS
FOLLOWING
FRACTURE
Fig. Figul re l-Radiograph
of orbital
apex of Case
I
OF
THE
ZYGOMATIC
BONE
13
I
showing di sconl :inuity (arrowed)
of optic foramcn.
oedematous. Further radiographic examination (Fig. 1) demonstrated a fracture with disruption of the right optic canal. Surgery was undertaken without delay to align the fractured zygomatic bone. This was accomplished using fronto-zygomatic and infra-orbital wires. The floor of the orbit was explored and found to be intact except for a single displaced fracture. A drain was inserted to decompress the orbital floor. Immediately after surgery the patient claimed she was able to see from the right eye and the direct and consensual pupil responses to light were slow but present. However, the following morning and to date, the patient remains blind in the right eye. Further radiographic examination the next day demonstrated no reduction of the fracture of the right optic canal. Case 2 A 22 year-old Caucasian male was referred to the Royal Liverpool Hospital following a road traffic accident. He had been rendered unconscious and sustained fractures of the left wrist, frontal bone and left and right supraorbital rims with disruption of the left optic canal (Fig. 2); there was a fracture of the left zygomatic bone in addition to a Le Fort II fracture and body fractures of the mandible. There was no proptosis or ophthalmoplegia of the left eye and no direct but a reduced right consensual response to light. The patient had a persistent cerebrospinal fluid leak which subsequently required neurosurgical repair. The patient remains blind in the left eye.
14
BRITISH
JOURNAL
OF
ORAL
&
Fig. Figure
2-Disruption
MAXILLOFACIAL
SURGERY
2
of optic
canal
(Case
2)
Discussion
Some previously reported cases of blindness associated with fractures or surgery to the zygomatic bone where blindness was accredited solely to a retrobulbar haemorrhage could possibly be due to fracture of the optic canal. Disruption of the optic canal, in addition to retrobulbar haemorrhage, may have occurred, and must be excluded when injuries of the orbital region have resulted in loss of vision. Postmortem investigation has demonstrated that injury to the optic nerve resulting from optic canal fractures is rarely the result of osseous compression, laceration of the nerve or haemorrhage into the nerve itself. More often haemorrhage into the optic sheath or contusion of the nerve results in oedema and compression (Pringle, 1922; Hughes, 1962; Walsh, 1969; Manfredi et al., 1981). The injury could lead to secondary compression of the vascular supply to the nerve where the nerve sheath is fixed to its bony surroundings. The ophthalmoscopic findings in reported cases of blindness attributed to retrobulbar haemorrhage do not always demonstrate the classical signs of posterior polar oedema and a cherry red macular spot of central retinal artery occlusion (Ord, 1981). Varley et al. (1968) and Nicholson and Guzak, (1971) demonstrated the signs, and Heinze and Hueston (1978), reviewing cases of blindness after blepharoplasty, state that these signs had not been reported. Radiographic demonstration of the fractures can be difficult. Optic canal views and tomograms of the orbit can demonstrate the fractures as in the present cases but these techniques can be unreliable (Turner, 1943; Hooper, 1951; Ramsey, 1979; Manfredi et al., 1981). Computerized tomographic scan has been used to demonstrate optic canal fractures (Manfredi et al., 19Sl), and is most useful when blindness has resulted or when spheno-ethmoidal sinus haemorrhage is seen on plain radiography. However, technical factors in CT scanning may prevent
BLINDNESS
FOLLOWING
FRACTURE
OF
THE
ZYGOMATIC
BONE
15
demonstration of the fracture (thickness of cut and plane) if a ‘state of the art’ scanner is not available. A CT scan however, will allow good resolution of soft tissues or haematoma that would not be evident from plain radiography. Blindness subsequent to orbital trauma or surgery may result from central retinal artery occlusion, a fracture disrupting the optic canal or from retrobulbar haemorrhage which may cause anterior optic nerve head ischaemia as described by Ord (1981). Orbital decompression alone in cases where the optic canal is grossly disrupted will be inadequate (Manfredi et al., 1981). However, Fukado (1973) reported the results of 400 transethmoidal decompressions of the optic nerve. The technique involved a medial approach under local anaesthesia to the anterior wall of the ethmoid sinus, which is removed to gain access to the optic canal. The inner wall of the optic canal is perforated, taking care that the periosteum and the dural sheath of the optic nerve are spared. However the paper does not report a restoration of vision following the procedure, and the technique remains to be tested when acute blindness results from disruption of the optic canal. Decompression of the optic nerve and/or realignment of the optic canal at the site of the fracture with inspection of the optic nerve cannot seriously be contemplated, as such a procedure would require an intra-cranial approach and the possible complications of such surgery are not acceptable (Foy, 1984). The use of intravenous or intra-muscular acetazolamide 500 mg, hydrocortisone 100 mg I.V. or Mannitol2OX rapid infusion (Ord, 1981) as the medical treatments of retrobulbar haemorrhage remain to be tested in the management of blindness due to a disrupted optic canal. Blindness in the present cases has resulted from fracture of the optic canal causing either direct damage to the optic nerve and/or occlusion of the ophthalmic artery. The patients did not exhibit all the features of retrobulbar haemorrhage. which led to the suspicion and discovery of fracture of the optic canal. It may be that a thick orbital bony floor (as in Case 1) may be significant in resulting in disruption of the optic canal rather than comminution of the orbital floor. The interceptive surgery and medical measures undertaken for the patients have not restored sight. In the first case this may have been the result of delay in surgery which was 10 hours, and more speedy action may possibly have had a more satisfactory outcome. Acknowledgements I would like to thank Mr Roger Ainley, Consultant Ophthalmologist at Arrowe Park Hospital, for his help in the management of the first case and for assistance in the preparation of this paper.
References Babajews, A. & Williams. J. (1986). Blindness after trauma insufficient to cause bony injury. British Journal of Oral and Maxillofacial Surgeq, 24, 7. Berlin, R. (1881). Injuries to the optic nerve and ophthalmic artery from fracture of the optic canal. Transactions of the Seventh Inlernational Medical Congress, Vol. 3. London: Kolckmann. p. 115. De Mere, H., Wood, T. & Austin, W. (1974). Eye complications with blepharoplasty and other eyelid surgery. Plastic and Reconstructive Surgery, 53, 634. Foy, P. M. (1984). Personal Communication. Fukado, Y. (1975). Results in 400 surgical cases of decompression of the optic nerve. Modern Problems in Ophthalmology, 14, 474. Gordon, S. & Macrae, H. (1950). Monocular blindness as a complication of a malar fracture. Plastic and Reconstructive Surgery, 6, 228.
16
BRITISH
JOURNAL
OF
ORAL
&
MAXILLOPACIAL
SURGERY
Gordon. S. (lYS7). Malar fracture: intra-orbital haemorrhage during open reduction. Plasric and Reconstrucrive Surgery, 20, 65. Heinze, J. B. & Hueston, J. T. (1978). Blindness after blepharoplasty; mechanism and early reversal. Plastic and Reconstructive Surgerv, 61, 347. Hooper, R. S. (19.51). Orbital comphcations of head injury. Briush Journal of Surgery, 39, 126. Huang. T. T., Horwitz & Lewis, S. R. (1977). Retrobulbar haemorrhage. Plastic und Reconstructive Surgery, 59, 39. Hueston. J. T. & Heinze, J. B. (1974). Successful early relief of blindness occurring after blepharoplasty. Plastic and Reconstrucrive Surgery, 53, 588. Hughes. B. (1962). Indirect injury to the optic nerves and chiasma. Rullerin of the John.v Hopkins Hospital, 111, 98. Long, J. C. & Ellis, P. P. (1971). Total unilateral visual loss following orbital surgery. Americun Journal of Ophthalmology, 71, 218. Magoon, R. C. (1963). Orbital fracture and retrobulbar haemorrhage. American Journal of Ophthalmology. 55, 370. Manfredi, S. J.. Raji, M. R., Sprinkle, P. M.. Weinstein, G. W., Minardi, L. N. & Swanson, T. J. (1981). Computerised tomographic scan findings in facial fractures associated with blindness. Plastic and Reconstructive Surgery, 68. 479. Nicholson. D. H. & Guzak, S. U. Jr. (1971). Visual loss complicating repair of orbital floor fractures. Archives of Ophthalmology, 86, 369. Ord, R. A. (1981). Post-operative retrobulbar haemorrhagc and blindness complicating trauma surgery. British Journal of Oral Surgery, 19, 202. Penn, J. & Epstein, E. (1953). Complication following late manipulation of impacted fracture of malar. British Journal of Plastic Surgery, 6, 65. Pringle, H. J. (1922). Atrophy of the optic nerve following diffused violence to the skull. British Medical Journal. 2, 1156. Putterman, A. H. (1975). Temporary blindness after blepharoplasty. American Journal of Ophthalmology, 80, 1081. Ramsey. J. H. (197Y). Optic nerve injury in fracture of the canal. British Journal of Ophthalmology,63, 607. Rowe, N. L. (1967). Cited by Varley, E. W. B.. Holt-Wilson, A. D. Acute retinal arterial occlusion following reduction of a fractured zygoma and its successful treatment. Turner. J. W. A. (1943). Indirect iniuries of the optic nerve. Bruin. 66. 140 Varley. E. W. B., Holt-Wilson, A. D.‘(lYnX). Acute retinal arterial occlusion following reduction of a British Journal of Orul Surgery, 6, 31. fractured zygoma and its successful treatment. Walsh, F. B. B Foyt. W. F. (1969). Clinical Neuro-Ophthalmology. Vol. 3, Third Ed. Baltimore: Williams and Wilkins. p. 2362.