Visual disturbances are common neurologic presenting symptoms. The most important symptoms are acute visual loss, chronic visual loss, and double vision. Ask any patient complaining of visual disturbances the following questions:
How long have you noticed these visual changes?'' Is the visual loss associated with pain?'' Did it occur suddenly?'' ' 'Do you have a history of glaucoma?'' Have you ever been told that you had a thyroid problem?' Do you have diabetes?''
Acute painless visual loss is caused by either a vascular accident or a retinal detachment. Painless loss of vision over a longer period occurs with compression of the optic nerve or tract or radiation. Glaucoma is often the cause of chronic, insidious, painless loss of vision. Acute narrow-angle glaucoma, however, may be responsible for transient loss of vision in association with intense ocular pain. Episodes of migraine may produce transient episodes of visual loss before the development of the headache. Amaurosis fugax is transient visual loss lasting up to 3 minutes and is a feature of internal carotid artery disease.
Double vision, or diplopia, is discussed in Chapter 10, The Eye. Ocular motor palsies, thyroid abnormalities, myasthenia gravis, and brain-stem lesions are well-known causes of diplopia. Ocular motor palsies can occur in trauma, multiple sclerosis, myasthenia gravis, aneurysms of the circle of Willis, diabetes, and tumors. Ask the following questions of any patient complaining of diplopia:
Are you diabetic?''
' 'In which field of gaze do you have double vision?'' Did the double vision occur suddenly?'' Was there any pain associated with the double vision?''
''Has there been any injury to your head or eye?'' Have you ever been told that your blood pressure was elevated?'' Does the double vision get worse when you are tired?''
''Have you been exposed to the AIDS [acquired immunodeficiency syndrome] virus?''
When a cranial nerve is affected, resulting in an extraocular muscle palsy, the patient may complain of diplopia in one field of gaze when the affected eye is unable to move conjugately with the other. Ocular palsies involve the third, fourth, and sixth cranial nerves. A complete third (oculomotor) nerve palsy causes ptosis, mydriasis, and loss of all extraocular movements except abduction. Trauma, multiple sclerosis, tumors, and aneurysms are the most frequent causes. Aneurysms of the posterior communicating artery can involve the third nerve, which passes near the artery on its way to the cavernous sinus. Cavernous sinus thrombosis, not infrequently seen in patients with AIDS, may also produce a complete third nerve palsy. Pupil-sparing third nerve, fourth (trochlear) nerve, and sixth (abducens) nerve palsies are seen in diabetic patients and in patients with long-standing hypertension. Patients with my-asthenia gravis often have diplopia in the later part of the day as the muscles tire and weaken.
Visual disturbances, including blocked vision or loss of vision in one eye, blurry vision, or ''graying out'' are seen frequently in patients suffering a stroke.
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All you need is a proper diet of fresh fruits and vegetables and get plenty of exercise and you'll be fine. Ever heard those words from your doctor? If that's all heshe recommends then you're missing out an important ingredient for health that he's not telling you. Fact is that you can adhere to the strictest diet, watch everything you eat and get the exercise of amarathon runner and still come down with diabetic complications. Diet, exercise and standard drug treatments simply aren't enough to help keep your diabetes under control.