Diplopia Due to Mask Barotrauma

The Journal of Emergency Medicine, Vol. 41, No. 5, pp. 486 – 488, 2011 Copyright © 2011 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$–see front matter

doi:10.1016/j.jemermed.2008.04.015

Clinical Communications: Adults DIPLOPIA DUE TO MASK BAROTRAUMA Emi Latham,

MD,

Karen van Hoesen,

MD,

and Ian Grover,

MD

Department of Emergency Medicine, Division of Hyperbaric Medicine, University of California, San Diego, San Diego, California Reprint Address: Emi Latham, MD, Department of Emergency Medicine, Division of Hyperbaric Medicine, University of California, San Diego, 200 West Arbor Drive, San Diego, CA 92103-8676

e Abstract—Background: Scuba diving is a very popular and safe sport. Occasionally divers will suffer an injury from barotrauma, decompression sickness or an arterial gas embolism. The history and physical examination are important when determining the etiology of the injury and its subsequent treatment. Objectives: This article will help readers identify key components of the history and physical examination in a patient to help differentiate between and injury caused by barotrauma or arterial gas embolism. Case Report: This is a case of a diver that was initially felt to have an arterial gas embolism after scuba diving. After obtaining further history and performing a detailed physical exam it was determined that his diplopia was due to barotrauma from his mask. This was confirmed by an orbital computed tomography (CT) scan. Summary: Scuba diving is a very safe sport. When injuries occur it is important to obtain a careful history and physical examination to determine the exact cause of the injury because treatments vary according to the type of injury. In this case, the history and physical examination showed that the only neurologic sign the patient had was diplopia, which is not consistent with a diagnosis of arterial gas embolism. The CT scan helped with the diagnosis because it proved the patient had an orbital hematoma causing his proptosis and double vision. © 2011 Elsevier Inc.

injury correctly is very important because decompression sickness and arterial gas embolism (AGE) need to be treated emergently with recompression therapy at a hyperbaric chamber. A full history and physical examination should be performed to help distinguish these more serious cases from other diving injuries that can occur. The following is the case of a diver who surfaced with diplopia. Initially, it was felt that his symptoms were due to an AGE, but after performing a complete history and physical examination, his symptoms were determined to be from mask barotrauma.

CASE REPORT A 41-year-old-man with no previous past medical history presented to the Emergency Department (ED) approximately 3 h after scuba diving, with a chief complaint of double vision. He was concerned because the double vision occurred after scuba diving. He never had visual changes like this before, and he stated that his vision was normal before his dive. He had one episode of nausea and vomiting, but denied other symptoms. The patient had previously performed 45 dives; his last dive was 2 months before this ED visit. He had never suffered any diving-related injuries in the past. He took Sudafed for nasal congestion before this dive to prevent problems equalizing his ears. The nasal congestion may have predisposed him to ear or sinus barotrauma. His dive profile consisted of a dive to 60 feet for about 5 min, and then he continued his descent to 90 feet.

e Keywords—scuba diving; barotrauma; orbital hematoma; dip

INTRODUCTION Scuba diving has become an increasingly popular sport. Despite advances in training and more sophisticated gear, diving injuries still occur. Diagnosing a diver’s

RECEIVED: 15 September 2007; FINAL ACCEPTED: 19 April 2008

SUBMISSION RECEIVED:

16 April 2008;

486

Diplopia Due to Mask Barotrauma

487

Figure 1. This series of images demonstrates hemorrhage above the right globe distinct from the eyeball itself, as indicated by the arrow in the image farthest to the right.

After about 6 min at 90 feet, he ascended with his partner back to 60 feet, where his partner signaled that he was out of air. The patient then followed his dive partner directly to the surface, taking about 30 s for their ascent. He denied holding his breath at any point during the rapid ascent. Once on the surface, he had to tow his dive partner to the dive boat because his partner was exhausted. Once on the boat, the patient had nausea with one episode of vomiting. At this point he noticed double vision. The patient noted problems with mask squeeze during descent, but he denied any visual changes until getting on the boat. The diplopia was noticed within minutes of getting on the dive boat and persisted through the time he presented to the ED. He denied any vertigo or difficulty with walking, and he denied any other neurologic symptoms. The dive partner who accompanied the patient to the ED did not have any problems, and he had not noticed any problems with the patient except for his double vision and that his right eye was slightly proptotic. On physical examination, his vital signs were all normal. His visual acuity in both eyes, tested individually, was 20/20, and his diplopia resolved with one eye covered. Both fundi were flat and sharp, and both pupils were equally round and reactive to light. The extraocular movements in the right eye revealed normal adduction and abduction, but he was unable to look upward. The left eye extraocular movements were found to be normal. Diplopia was worse with extreme movements of the eyes to the left or right, as well as upward gaze. He did not have any diplopia with downward gaze. He was noted to have a subconjunctival hemorrhage on the medial aspect of his right eye, and the right eye was also noted to be proptotic. Another finding was that he had periorbital

petechiae bilaterally. His ear examination revealed that he had bilateral Grade II barotrauma, with hemorrhage into both tympanic membranes but no gross hemotympanum. His neurologic examination was normal except for the double vision. The patient was placed on 100% oxygen via nonrebreather mask for presumed treatment of an AGE. His complete blood count and basic chemistry panel were normal. He did have an elevated creatine phosphokinase, but this was probably related to his 3-h bicycle ride the day before his dive, as well as his exertion while towing his friend to the boat. His chest X-ray study did not reveal any cardiopulmonary disease or any sign of barotrauma, and his electrocardiogram was normal. Due to his proptosis on the right side, the patient was sent to Radiology for a computed tomography (CT) scan of the orbits to evaluate for hemorrhage or air. The CT scan showed an intraorbital hematoma at the anterosuperior portion of the right orbit (Figure 1). This produced a mass effect that pushed the right eye inferolaterally, causing proptosis. These findings, in conjunction with his history and physical examination, supported the diagnosis of an orbital hematoma from mask barotrauma. The patient was then discharged home, referred to an ophthalmologist, and advised to keep his head elevated and to place ice over his right orbit for 15 min, four times a day. The patient had a magnetic resonance imaging (MRI) scan the next morning, which confirmed the CT findings. A few weeks later, a follow-up telephone call was made to the patient. He reported that his proptosis and double vision had both resolved. He was going to resume diving, but he was going to do so with precautions to prevent further mask barotrauma.

488

E. Latham et al.

DISCUSSION Orbital hemorrhage after mask barotrauma during scuba diving is an infrequent occurrence (1– 4). In this case, the patient developed the symptom of diplopia quickly after a rapid ascent, which could suggest an AGE. An AGE can present with a variety of neurologic symptoms such as loss of consciousness, dizziness, paralysis, abnormal sensation, blurred vision, or convulsions. Symptoms often present during ascent or within minutes of surfacing (5). The patient’s only complaint was diplopia. He had no other neurologic symptoms such as blurred vision, loss of consciousness, persistent symptoms of altered mentation, or numbness or weakness in an extremity, to suggest an AGE. This patient was noted to have proptosis of his right eye as well as periorbital petechiae and a subconjunctival hemorrhage on the right. A subconjunctival hemorrhage and petechia are common physical examination findings of mask barotrauma. They are the result of a vacuum effect created by the air space between the dive mask and the diver’s face. The patient had an orbital CT scan done, and an orbital hemorrhage was noted. Spontaneous orbital hemorrhage is unusual in young, healthy individuals. One proposed mechanism is increased intra-abdominal or thoracic pressures that cause increased central venous pressure, which is then transmitted directly to the avalvular orbital vessels. Patients have developed subperiosteal orbital hematomas induced by the Valsalva maneuver (2). A second mechanism for producing orbital hematomas is the suction theory. There is a case report of a 24-year-old-man who was inspecting a hose when it slipped and sealed to his face. This created a negative pressure of 0.5 atmosphere for 15 s and caused diffuse swelling and hemorrhages around his orbits (3). Our patient experienced a severe mask squeeze by not equalizing the pressure inside his mask with the pressure from the water around him at depth. At 90 feet, a possible pressure differential of almost 3 atmospheres between the water column and the inside of a diver’s mask can exist. The suction that may result from this pressure differential can cause significant strain on the small vessels in the orbit and within the globe, causing them to rupture. A scuba diver developed subperiosteal hemorrhage from mask squeeze in a situation similar to that of our patient (4). In all cases, patients had return of normal vision when the hematoma and swelling resolved. Both

CT and MRI have been used to diagnose orbital barotrauma (6). Our patient’s CT scan documents normal cortical gray matter, subcortical and deep white matter, ventricles, basal ganglia, and basilar cisterns. The sinuses are aerated, and the left orbit is normal. The right side has a 2.1 ⫻ 0.9 cm high attenuation lesion, consistent with an intraorbital hematoma, in the anterosuperior portion of the right orbit. Mass effect pushes the right eye inferolaterally, causing proptosis. Our patient’s visual changes may have been present at depth, but his attention was more likely on his dive partner than on his own vision. Also, the initial trauma may have occurred at depth, but it would have taken time for enough blood to collect to cause his double vision. It is also possible that this patient may have increased the size of his hematoma by the physical exertion he put forth towing his partner to the dive boat and boarding the boat. It is likely that the nausea and vomiting he experienced was secondary to his double vision.

CONCLUSIONS Diving injuries can vary from self-limited injuries such as contusions and ear barotrauma to life-threatening conditions such as decompression sickness and arterial gas embolism. As with any medical problem, obtaining a good history and performing a careful physical examination will help to develop an appropriate differential diagnosis and guide further testing or treatment. This case presents a patient with a concerning physical finding that was not the result of decompression sickness or arterial gas embolism. When in doubt, contact a medical diving specialist if you have any questions about a diving accident or injury.

REFERENCES 1. Andenmatten R, Piguet B, Klainguti G. Orbital hemorrhage induced by barotraumas. Am J Ophthalmol 1994;118(4):536 –7. 2. Butler FK, Gurney N. Orbital hemorrhage following face mask barotrauma. Undersea Hyper Med 2001;8:31– 4. 3. Carson WK, Mecklenburg B. The role of radiology in dive-related disorders. Mil Med 2005;170(1):57– 62. 4. Rudge FW. Ocular barotraumas caused by mask squeeze during a scuba dive. South Med J 1994;87(7):749 –50. 5. U.S. Navy Diving Manual. Diving disorders requiring recompression therapy, vol. 5, revision 4. 1999;20:1–2. 6. Stern JH, Meyer DR. Orbital barotrauma. Ophthal Plat Reconstr Surg 1995;11(1):49 –53.