As you and your partner head to the dispatched address, the local fitness center, you ask the dispatcher to confirm the nature of the call. “Loss of vision” is the response. “Hmm, interesting,” your partner says. As you arrive at the fitness center, staff meets you at the door; escorting you to the locker room, they tell you they’re concerned the patient has experienced a stroke. Entering the locker room, you see a man in his 40s lying on one of the benches with a towel over his face. His friend is with him and tells you the patient was running on a treadmill when he suddenly lost the ability to see out of his right eye. The friend helped the patient back to the locker room; when the patient’s eyesight did not return, he asked the fitness center staff to call 9-1-1.
The patient is awake, responsive and oriented. He verifies his friend’s story and tells you it was as though someone slid an eye patch over his right eye. He denies any pain—currently or with the initial onset, any recent traumatic injuries to his head and any headache. His only other complaint is that he feels a little nauseous being able to see only out of one eye.
Your physical exam of the patient reveals no obvious signs of trauma, such as bruising, swelling or abrasions. The ocular exam reveals bilateral eye movement when evaluating the six points of gaze. There isn’t obvious swelling to the conjunctiva or surrounding tissue. The sclera of both eyes is white and there’s no obvious discharge from around the eye other than normal lacrimation. The finding of note is a prominent afferent papillary defect: The right eye doesn’t respond to light. A physical exam reveals no other obvious finding. The Cincinnati Stroke test is negative and there noted alteration in the patient’s speech. Pulse is 78 and blood pressure is 158/88.
The patient’s history includes hypertension and high cholesterol, both of which are being controlled with medication and exercise. He denies history of stroke or heart attack. The patient is kept comfortable during transport with no change in his visual acuity.
An acute loss of vision can be a scary event for patients. When a patient loses their sight acutely, it may affect any visual field; in other words, they may lose their right or left side peripheral vision, their lower field of vision or total vision. Depending on the cause, visual acuity may be lost in one eye or both eyes. It may be transient or permanent. The determination of the latter may be based in part on the response from EMS the emergency department (ED).
The most common cause of acute vision loss is ischemia.(1) The pathophysiology isn’t much different from that seen in a stroke or myocardial infarction. There’s an acute loss of blood to the eye, resulting in partial or complete loss of vision. These patients commonly have an underlying history of atherosclerotic disease. Other risk factors include hypertension, smoking, diabetes and sickle cell. Ischemic-caused visual loss is most commonly seen in Caucasian males with an overall prevalence in males over females 2:1.(1) The goal in the management of ischemic visual loss is reperfusion of the eye. Treatments in the ED may include pressure applied to the closed eye and the administration of carbogen, a mixture of oxygen and carbon dioxide.(2)
Other causes of acute vision loss include retinal detachment, which is a separation of the membrane at the back of the eye (retina). Retinal detachment may be caused by trauma but is also seen in patients with diabetes or family history of retinal detachment. Symptoms of retinal detachment may include flashes of bright lights in the peripheral vision, blurred vision and shadows or blindness in a field of vision in one eye. Surgery is required for repair.
Angle-closure glaucoma is caused by the acute obstruction of the anterior chamber angle, which allows aqueous humor to leave the anterior chamber of the eye. When occluded, there’s a rapid rise in ocular pressure causing severe pain, cloudy vision and a feeling of having a swollen eye. Patients may also present with nausea and vomiting as well as seeing halos in their field of vision. Acute angle-closure is a medical emergency. Surgery (iridotomy) is usually required to remedy the situation. This condition can be precipitated by the use of anticholinergic medications such as atropine and atrovent.(1)
A final cause of acute blindness: syphilis, a sexually transmitted disease that presents initially with genital lesions. If not treated, syphilis can cause uvietis, which is the inflammation of the middle layer of the eye. This inflammation can obstruct blood supply to the retina, causing vision loss.
There are many other causes of acute vision loss, including sarcoidosis, central retinal vein occlusion and such toxins as methanol.
Treatment for acute blindness is specific to the cause of the visual loss. Most of the treatment is outside the scope of EMS providers. This shouldn’t detract from the potentially critical nature of the condition. EMS should acknowledge the complaint of acute visual loss or alteration of vision and obtain a complete history that includes recent trauma, past medical conditions, such as diabetes and atherosclerosis, recent ingestion of toxins and recent infections. Support the patient because acute vision loss can be anxiety provoking. Notify the receiving facility and transport. Best outcomes occur with recognition, identification of cause and appropriate interventions.
1. Farina G. (Jan. 14, 2011). Sudden Visual Loss. In Medscape.com. Retrieved from http://emedicine.medscape.com/article/1216594-overview.
2. Marx J, Hockberger R, Walls R et al. Rosen’s Emergency Medicine: Concepts and Clinical Practice, 6th edition, Vol. 2. Elsevier Health Sciences: St. Louis, 2005.