Retinal Phenomena
Retinal Phenomena: Excerpt from Field Guide to Bedside Diagnosis
Differential Overview
❑ Hypertension
❑ Diabetic retinopathy
❑ Glaucoma
❑ Cholesterol emboli
❑ Papilledema
❑ Pigmented crescent
❑ Macular degeneration
❑ Retinal detachment
❑ Acute optic neuritis
❑ Optic atrophy
❑ Retinal hemorrhage
❑ Chorioretinal exudates
❑ Lipemia retinalis
❑ Central retinal artery occlusion
❑ Central retinal vein occlusion
❑ Angioid streaks
❑ Hyperviscosity
Clinical Findings
Hypertension A significant AV crossing change is one that is two disc diameters out and that obliterates the venous column of blood. This is because of longstanding arterial muscular hypertrophy, and it will remain even after the hypertension is treated. Accelerated hypertension is most readily recognized by retinal hemorrhage, which is a marker for a similar pathophysiology in the brain.
Diabetic retinopathy Diabetic retinopathy most often involves microaneurysms, dot hemorrhages, and exudates. Neovascularization around the optic disc heralds retinal and vitreous hemorrhage, which leads to blindness.
Glaucoma The optic cup-to-disc ratio is increased, and striations can be seen on the surface of the cup. The cup is several diopters deep, with vessels visibly rising over the lip of the disc.
Cholesterol emboli A brightly refractile yellow embolus impacts at an arteriolar branch point. This is important to recognize as a marker of an ulcerated carotid plaque.
Papilledema The optic disc becomes edematous, which is manifest as an indistinct disc margin, hyperemia, and absence of venous pulsations. The usual implication is raised intracranial pressure.
Pigmented crescent This is a normal finding adjacent to the disc, and its appearance corresponds to the degree of skin pigmentation.
Macular degeneration Macular drusen, atrophy of the retinal pigment with prominent choroidal vessels, subretinal edema or hemorrhage, and a central fibrous scar are typical findings.
Retinal detachment The retina appears to billow in undulating folds. It is difficult to keep vessels in focus because they cross focal planes.
Acute optic neuritis On examination it appears very similar to papilledema, but there is decreased visual acuity as opposed to an enlarged physiologic blind spot.
Optic atrophy It appears as a porcelain-white disc with sharply demarcated edges.
Retinal hemorrhage Retinal hemorrhage is found in accelerated hypertension, diabetes, pernicious anemia, DIC, leukemia, and subarachnoid hemorrhage. In endocarditis, a Roth spot (focal hemorrhage with a clear center) may be found.
Chorioretinal exudates Cytomegalovirus retinitis in a patient with AIDS has an appearance of a yellow granular exudate with hemorrhage at the advancing border. These should be distinguished from the cotton-wool spots caused by HIV infection alone. White cotton-like lesions in a febrile immunocompromised patient suggest systemic candidiasis.
Lipemia retinalis The retina and retinal vessels have a pale yellow appearance in hypertriglyceridemia.
Central retinal artery occlusion The optic disc is pale, the retina is edematous, the macula appears cherry-red, and there are “boxcar veins.”
Central retinal vein occlusion Veins are tortuous and dilated, the retina is edematous and has flame hemorrhages, and the optic disc margin is blurred.
Angioid streaks Dark linear streaking of the retina in pseudoxanthoma elasticum appears like ghosts of traversing vessels. This condition is associated with accelerated peripheral vascular and coronary artery disease.
Hyperviscosity Tortuous sausage-link retinal veins are found in
macroglobulinemia.
Book Source Details
- Book Title: Field Guide to Bedside Diagnosis
- Author(s): David S. Smith
- Year of Publication: 2007
- Copyright Details: Field Guide to Bedside Diagnosis, Copyright © 2007 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: Field Guide to Bedside Diagnosis
Authors: David S. Smith
Publisher: Lippincott Williams & Wilkins
Copyright: 2007
ISBN: 0-78178-165-5
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