EDITOR:
Blunt orbital trauma with need of surgical repair is common. Postoperative complications are rare but may include retrobulbar haematoma [Reference Bailey, Kuo and Evans1], which may be serious since it can evolve rapidly into visual impairment or even permanent loss of vision [Reference Zachariades, Papavassiliou and Christopoulos2]. Anaesthetists implicated in the postoperative care of such patients should be aware of this problem and its symptoms in order to act rapidly in an adequate way. Isolated treatment of pain and nausea and vomiting may result in permanent loss of vision within hours.
Acute retrobulbar haemorrhage can follow as a severe complication of trauma, retrobulbar injections [Reference Girard3], orbital surgery or even minor eyelid surgery [Reference Hass, Penne, Stefanyszyn and Flanagan4] with potentially devastating consequences such as loss of vision. Being aware of this potential complication and a rapid computed tomography (CT) scan may prevent grave sequel. This case highlights the need for increased awareness after blunt orbital trauma and orbital surgery.
Case report
A 41-yr-old male was involved in a dispute and punched in the face. In the emergency room the patient was conscious, had amnesia for the event, a right periorbital ecchymosis and haematoma but no nausea, vomiting or any visual deficit. A CT scan of the skull and brain revealed a fracture of the right maxillary sinus, including a haematosinus and a medial and inferior orbital wall fracture with a minor enophtalmus. Clinically, the patient described a minimal infra- and supraorbital hypoesthesia. The patient was transferred to an intermediate care unit for neurological surveillance and a conservative treatment was planned for the orbital wall fracture. Routine blood tests, including coagulation studies, were within norm ranges.
Over the next 7 days, the hypoesthesia did not improve and the decision for surgical intervention was taken. The plastic and reconstructive surgeons performed a neurolysis of the infraorbital nerve and introduced a poly-p-dioxanon plate (PDS plate, 0.5 × 40 × 50 mm; Johnson & Johnson, Spreitenbach, Switzerland) to correct the enophtalmus. The patient was instructed not to blow his nose within the next 2 weeks.
Despite these instructions, the patient did blow his nose and massive pain and nausea and vomiting developed rapidly. This happened within 12 h after surgery; for this reason the plastic surgeons called the anaesthetist responsible for postoperative pain management demanding a better treatment for pain, nausea and vomiting. To the anaesthesiologist, the intensity of pain appeared excessive for the type of surgery performed a few hours ago and the sudden onset of severe nausea and vomiting also appeared unusual. Clinically, the patient had an exophthalmus, which was difficult to visualize due to postoperative swelling and dressings.
For these reasons a CT scan of the skull and the orbit was performed. These images revealed (Fig. 1) a massive right retrobulbar haemorrhage with marked proptosis and tenting (deformation) of the globe by the stretched optic nerve. The right pupil was deformed, indicating an optic nerve compression (relative afferent pupillary defect (RAPD)) and vision was reduced to 0.4 (normal = 1.0). The proptotic eye was immobile (‘frozen globus’).
Figure 1 Transaxial computed tomography (CT), showing the retrobulbar haematoma and exophthalmus on the right hand side with compression of the inferior rectus muscle and compression of the optic nerve.
An emergency revision with evacuation of the haematoma and removal of the PDS implant was performed. At the end of this procedure the globe was back in its proper position with improved extraocular movement and reduced RAPD. A few weeks later, the vision of the right eye was restored to 0.9 with full visual field and minimal residual RAPD. No postoperative CT scan was performed.
Discussion
Loss of vision is a complication of maxillo-facial trauma occurring in 0.67–3% of cases [Reference Zachariades, Papavassiliou and Christopoulos2]. In a retrospective study [Reference Girotto, Gamble and Robertson5] an incidence of loss of vision of 0.24% was found as a complication of surgery for orbital fractures; in 48% of the cases a retrobulbar haematoma was identified as the cause of this devastating complication.
There is general agreement that the damage to the visual system caused by haematoma is the result of increased intraorbital pressure, which results in a decreased perfusion, representing a ‘compartment syndrome’. Bleeding frequently originates from the infraorbital artery or one of its branches.
Owing to the anatomy of the orbit within inflexible walls, even a small haematoma may have catastrophic consequences. In fact, the orbital tissue seems to respond to fluid overload in such a way that once the hydraulic system of the orbit is exhausted, even small changes in volume can cause a dramatic increase in orbital pressure [Reference Bailey, Kuo and Evans1,Reference Korinth, Ince, Banghard, Huffmann and Gilsbach6]. This pathology is also found in acute glaucoma. The pressure does not increase that dramatically when the haematoma finds its way into the periorbital sinuses via the orbital wall fracture. In this patient, however, this escape route was not possible because of the PDS plate in place.
An orbital haematoma can cause complications ranging from vascular compression to acute stretching of the optic nerve resulting from proptosis. The accompanying retrobulbar oedema may additionally reduce retinal perfusion and compress the long and short ciliary vessels, leading to ischaemic damage to the optic nerve. In most cases the ischaemia occurs to the anterior part of the optic nerve [Reference Ord7]. The optic nerve provides some protection to the enclosed central retinal artery from direct compression. The higher systolic pressure of this artery also gives some added protection. Other vessels lying within muscle cones and entering the eye around the optic nerve do not have such protection. These include the prepapillary choroid and post ciliary arteries. Loss of vision can therefore occur without central artery occlusion and has been documented as anterior ischaemic neuropathy [Reference Winterton, Patel and Mizen8].
In some cases the vision is not at risk but displacement of the orbital structures by haematoma interferes with ocular motility and function.
In the present case, the most critical aspect of orbital haematoma treatment is the rapidity of the diagnosis and the decision to perform immediate surgical drainage. Any delay between the onset of symptoms and orbital decompression can have a marked effect on functional recovery. It has been stated that if decompression is carried out within 2 h of the onset of symptoms it is likely to be successful in avoiding permanent damage [Reference Hislop and Dutton9].
Emergency lateral canthotomy with inferior cantholysis has been recommended as first-line treatment to reduce intraorbital and intraocular pressure while waiting for a CT scan and definitive surgery. It is a safe and often effective procedure to be performed even without any anaesthesia on a patient entering the emergency room with clinical suspicion of a retrobulbar haemorrhage [Reference Goodall, Brahma, Bates and Leatherbarrow10]. Our patient was agitated, vomiting and ready to go to the operating theatre with a CT scan showing a major localized haemorrhage needing to be evacuated. Therefore no time was lost with a lateral canthotomy.
Clinical diagnosis is based on a painful proptosis with or without visual deficit or loss of pupil reflex and nausea and vomiting. These symptoms are partially generated due to the rising intraocular pressure, which is ‘acute glaucoma’ due to the impossibility that liquid can leave the front chamber of the eye. An emergency multi-slice CT scan is a fundamental diagnostic aid.
The fundamental error that could have occurred in this case would have been to non-specifically treat pain with opioids and nausea and vomiting by central acting drugs such as serotonin antagonists, droperidol or dexamethasone. Symptoms would have been attenuated but the patient might have definitely have lost his vision on this eye.
In conclusion, retrobulbar haematoma is a rare but severe complication of surgery for orbital fractures, with potentially devastating consequences such as loss of vision. Being aware of this potential complication and a rapid CT scan may prevent grave sequelae as well as the search of surgical complications in the immediate postoperative period.
