Eye Symptoms and Signs Flashcards
Anisocoria. What is it?
<ul><li>Difference in pupil diameters as viewed in dim illumination </li> <li>May be physiologic (normal variant) if diameter difference is 1mm or less and both pupils react briskly and equally to light </li> <li>Pathologic causes are eye inflammation (<a>anterior uveitis</a>) or trauma (including eye surgery), medication instilled in eye, damage to ciliary ganglion or ciliary nerves ("<a>tonic pupil</a>"), <a>third nerve palsy</a>, <a>Horner syndrome</a></li> </ul>
Anisocoria. How does it appear?
<ul><li>Call it pathologic if anisocoria greater than 1mm in dim illumination, one pupil constricts poorly to light, or pupil shape irregular</li><li>If you find ptosis on side of smaller pupil, consider <a>Horner syndrome</a></li><li>If you find ptosis, diplopia, or abnormal eye movements or alignment, consider <a>third nerve palsy</a></li><li>Irregular pupil shape suggests <a>anterior uveitis</a>, <a>tonic pupil</a>, and eye trauma (including intraocular surgery) </li><li>Remember that anisocoria can be caused by instilled anticholinergic or sympathomimetic eye drops, or accidental contamination from plants or medicated skin patches and aerosols</li><li>If pupil constricts very slowly to light and dilates very slowly when light is withdraw, consider tonic pupil caused by damage to ciliary ganglion or nerves in orbital disorders (including surgery)</li></ul>
Anisocoria. What else looks like it?
<ul> <li>Nothing—you should be able to tell if two pupils are different in size </li> <li>Challenge is to decide whether anisocoria is pathologic</li> </ul>
Anisocoria. How do you manage it?
<ul><li>Measure amount of anisocoria in dim illumination; more than 1.5mm usually pathologic, especially if pupil constricts poorly to light</li> <li>Refer to ophthalmologist if findings suggest pathologic anisocoria </li> <li>Refer urgently if you suspect third nerve palsy (could be caused by intracranial aneurysm) or Horner syndrome (could be caused by arterial dissection or tumor) </li> </ul>
Anisocoria. What will happen?
<ul><li>Measure amount of anisocoria in dim illumination; more than 1.5mm usually pathologic, especially if pupil constricts poorly to light</li> <li>Refer to ophthalmologist if findings suggest pathologic anisocoria </li> <li>Refer urgently if you suspect third nerve palsy (could be caused by intracranial aneurysm) or Horner syndrome (could be caused by arterial dissection or tumor) </li> </ul>
Diplopia. What is it?
<ul> <li>Double vision, or seeing 2 copies of viewed objects</li> <li>If diplopia persists with either eye covered ("monocular diplopia"), cause is optical </li> <li>Optical causes of monocular diplopia are uncorrected refractive error and surface irregularity or opacity of cornea or lens </li> <li>If diplopia disappears with either eye covered ("binocular diplopia"), cause is misalignment of eyes </li> <li>Misalignment of eyes may arise from disorders of brain stem, ocular motor cranial nerves, neuromuscular transmission, or extraocular muscles</li> </ul>
Diplopia. How does it appear?
<ul><li>Monocular diplopia usually disappears when eye looks through pinhole</li><li>Binocular diplopia always accompanied by misalignment of eyes, but that may not be obvious</li></ul>
Diplopia. What else looks like it?
<ul><li>Patients with psychogenic visual loss may report monocular diplopia, but it does not disappear with pinhole</li><li>Patients with binocular diplopia may report blurred rather than double vision, "something wrong with my vision," or no symptoms at all</li> </ul>
Diplopia. How do you manage it?
<ul> <li>Assess whether diplopia is monocular (optical) or binocular (misalignment)</li> <li>Monocular diplopia is non-urgent problem</li> <li>Binocular diplopia, especially if new, is urgent problem, so refer promptly to ophthalmologist or emergency room</li> </ul>
Diplopia. What will happen?
<ul><li>First step in diagnosis is to localize responsible lesion, with these possibilities...</li><li>Brain stem lesion: <ul><li><a>Internuclear ophthalmoplegia</a>: in young people, most common cause is multiple sclerosis; in older people, most common cause is stroke</li></ul></li><li>Ocular motor nerve lesion: <ul> <li><a>Third cranial nerve palsy</a>: most common cause is ischemia, but expanding or ruptured aneurysm is chief concern. Brain vascular imaging must be performed urgently to rule out aneurysm. Other considerations are neoplasm and inflammation. </li><li> <a>Fourth cranial nerve palsy</a>: most common cause is head trauma; in its absence, palsy can result from weakening of congenitally abnormal tendon or ischemia. Neoplasms and inflammation are rare causes.</li><li> <a>Sixth cranial nerve palsy</a>: apart from head trauma, most common cause is ischemia. Increased or decreased intracranial pressure, neoplasms, inflammation are other considerations.</li><li><a>Unilateral ophthalmoplegia</a>: usually results from lesions in the cavernous sinus or orbit, including neoplasm, fistula, inflammation, and thrombosis. </li></ul></li><li>Neuromuscular junction lesion: <ul> <li><a>Myasthenia gravis</a>: can mimic an ocular motor palsy or internuclear ophthalmoplegia; often accompanied by ptosis or other manifestations of weakness, which fluctuates and is worsened by use. <a>Ptosis</a> eliminated by injection of edrophonium chloride (Tensilon) or by sleep or <a>after ice placed on closed lid</a>.</li></ul></li><li>Extraocular muscle lesion: <ul><li><a>Restrictive ophthalmopathy</a>: applies to eye movements impaired by scarring, shortening, or swelling of extraocular muscles, most often caused by extraocular muscle inflammation (as in Graves disease) or orbital infection.</li></ul></li></ul>
Distorted Vision (Metamorphopsia). What is it?
<ul> <li><a>Visual illusion that objects appear warped</a> because their borders are curved or bent</li> <li>When monocular, usually results from displacement of foveal cone photoreceptors by hemorrhage, edema, or scarring </li> <li>Major causes are <a>age-related macular degeneration</a>, central serous chorioretinopathy, epiretinal membrane formation, <a>retinal detachment</a>, ocular trauma or inflammation </li> <li>When binocular and persistent, consider abnormal processing in visual cortex in stroke or other lesions</li> <li>When binocular and transient, consider transient ischemic attack, migraine, or occipital seizure </li></ul>
Distorted Vision (Metamorphopsia). How does it appear?
<ul><li>Viewed objects have curved borders</li><li>In retinal lesions, viewed objects may appear relatively small ("micropsia") or large ("macropsia") in affected eye</li><li>In visual cortex lesions, viewed objects may have grotesque distortions ("looks like a Picasso painting")</li></ul>
Distorted Vision (Metamorphopsia). What else looks like it?
<ul><li>New glasses that correct for previously uncorrected astigmatism can give a similar illusion</li><li>Scotomas (blank or dark areas in field of vision) can make vision appear so disturbed that patients report it as distorted</li></ul>
Distorted Vision (Metamorphopsia). How do you manage it?
<ul> <li>Persistent monocular visual distortion forces attention to retina </li> <li>Persistent or transient binocular visual distortion forcesattention to brain</li></ul>
Distorted Vision (Metamorphopsia). What will happen?
<ul> <li>Many retinal and brain causes are treatable and some require immediate intervention </li> <li>Outcomes vary depending on cause of this visual illusion </li></ul>
Flashes and Flickers. What is it?
<ul><li>Flashes are bright sparks or streaks of light that appear suddenly and briefly in vision</li><li>Flashes usually come from tugging on retinal photoreceptors, which may signalimpending or actual <a>vitreous detachment, retinal hole, or retinal detachment</a></li><li>Flickers are sparkles that shimmer in vision ("scintillations") </li><li>Flickers usually come from activated visual cortex in migraine, but importantly also in transient ischemic attack, seizure, damaged retina, and damaged optic nerve</li></ul>
Flashes and Flickers. How does it appear?
<ul> <li>Flashes appear abruptly like lightning bolts in outer edge of visual field</li> <li>Flashes may be provoked by eye movement</li><li>Flickers may be transient or persistent</li><li>Flickers that are part of <a>visual aura of migraine</a> often expand across hemifield in 20-30 minutes and disappear</li><li>Flickers of migraine usually precede headache and other manifestations</li> <li>Flickers of damaged retina or optic nerve are often persistent</li></ul>
Flashes and Flickers. What else looks like it?
<ul><li>Halos around viewed objects (corneal disorders, <a>acute angle-closure glaucoma</a>)</li><li>Yellow-tinged borders ("xanthopsia") around viewed objects (digitalis excess, other medications)</li><li>Strobe-like hallucinations (anxiety)</li></ul>
Flashes and Flickers. How do you manage it?
<ul><li>Refer patient with flashes urgently to ophthalmologist because they suggest intraocular disorder (vitreous, retina, optic nerve)</li><li>Refer patient with flickers urgently to ophthalmologist, neuro-ophthalmologist or neurologist unless diagnosis of migraine is obvious because they could also suggest transient ischemic attack or seizure</li></ul>
Flashes and Flickers. What will happen?
<ul> <li>Vitreous detachment may rarely cause retinal tear and detachment which must be repaired promptly to protect vision</li><li>Visual aura of migraine is usually harmless, but transient ischemic attack and seizure have health consequences</li></ul>
Floaters. What is it?
<ul><li>Fragments of <a>solid vitreous suspended within clear vitreous gel</a></li><li>Appear suddenly when <a>posterior vitreous detaches from retina</a> as part of aging process </li><li>May signal <a>retinal tear or detachment</a></li><li>Could also represent vitreous hemorrhage, inflammation, cancer, or simply...</li><li>Normal phenomenon in high myopia </li></ul>
Floaters. How does it appear?
<ul><li>Like veils, webs, rings, or specks that float in and out of view</li><li>Patients first think that "my glasses are dirty" </li></ul>
Floaters. What else looks like it?
<ul><li>Tiny specks of uncertain origin that appear against blue sky or white walls from time to time </li></ul>
Floaters. How do you manage it?
<ul><li>If floater is new or disturbing, refer promptly to ophthalmologist because of concern for retinal tear and detachment, vitreous hemorrhage, or vitreous inflammation or cancer </li></ul>
Floaters. What will happen?
<ul> <li>Vitreous detachment could bring about retinal tear or detachment which requires urgent repair to prevent vision loss</li><li>Vitreous hemorrhage could reflect diabetic retinopathy, uncontrolled hypertension, or low platelet count</li><li>Vitreous cells could reflect intraocular inflammation or cancer</li></ul>
Foreign Body Sensation. What is it?
<ul><li>Sensation of having "sand in my eye"</li><li>Often accompanied by photophobia (abnormal sensitivity to light)</li><li>Caused by exposure of corneal trigeminal nerve endings because of surface epithelial defect</li><li>Common causes: traumatic abrasions (from corneal or conjunctival foreign bodies), surface erosions from drying, exposure, infection </li></ul>
