The Massachusetts Eye and Ear Infirmary Illustrated Manual of Ophthalmology, 4th Ed.

9. Vitreous

Amyloidosis

Asteroid Hyalosis

Persistent Hyperplastic Primary Vitreous

Posterior Vitreous Detachment

Synchesis Scintillans

Vitreous Hemorrhage

Vitritis

Amyloidosis

Definition

Group of diseases characterized by abnormal protein production and tissue deposition. Nonfamilial and familial forms; familial amyloidosis (autosomal dominant [AD]) caused by substitution errors in coding of prealbumin. Can be associated with multiple myeloma.

Symptoms

Floaters, decreased vision; may have diplopia.

Signs

Although any part of the eye can be involved, vitreous involvement is most commonly seen with granular, glass-wool opacities that form in the vitreal cortex, strands attached to the retina, retinal vascular occlusions, cotton wool spots, retinal neovascularization, and compressive optic neuropathy. Other findings include eyelid hemorrhages, ptosis, proptosis, dry eye, corneal deposits, iris stromal infiltrates, and ophthalmoplegia. Systemic findings in nonfamilial forms include polyarthralgias, pulmonary infiltrates, waxy, maculopapular skin lesions, renal failure, postural hypotension, congestive heart failure, and gastrointestinal bleeds. Systemic findings in familial form include autonomic dysfunction, peripheral neuropathies, and cardiomyopathy.

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FIGURE 9-1 Amyloidosis demonstrating the characteristic granular, glass-wool opacities in the midvitreous cavity that obscures the view of the retina. The optic nerve is barely visible.

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FIGURE 9-2 Amyloidosis demonstrating the characteristic granular, glass-wool opacities in the anterior vitreous cavity as seen with slit-lamp.

Differential Diagnosis

Asteroid hyalosis (see below), vitritis, old vitreous hemorrhage.

Evaluation

• Complete ophthalmic history and eye exam with attention to tonometry, iris, lens, anterior vitreous, Hruby lens, noncontact biomicroscopic or contact lens fundus exam, and ophthalmoscopy.

• Lab tests: Complete blood count (CBC), serum protein electrophoresis, liver function tests, chest radiographs, and 12-lead electrocardiogram.

• Diagnosis made on biopsy (dichroism; birefringence with Congo red stain).

• Medical consultation.

Management

• May require systemic treatment.

• No treatment recommended for vitreous involvement unless opacities become so severe that they affect vision, then consider pars plana vitrectomy by a retina specialist; recurs even after vitrectomy.

Prognosis

Variable depending on systemic involvement.

Asteroid Hyalosis

Multiple, yellow-white, round, birefringent particles composed of calcium phosphate soaps attached to the vitreous framework. Common degenerative process in elderly patients over 60 years of age (0.5% of population). Usually asymptomatic, does not cause floaters or interfere with vision, but does affect view of fundus; usually unilateral (75%); associated with diabetes mellitus (30%); good prognosis. Also does not affect fluorescein angiogram (FA) or optical coherence tomography (OCT) so both tests can be used to determine whether there are any retinal problems when the asteroid particles impair a direct view of the retina.

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FIGURE 9-3 Asteroid particles in the anterior vitreous cavity behind the lens. They are best seen using a fine slit-beam at an oblique angle.

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FIGURE 9-4 The yellow-white particles of asteroid hyalosis are seen over the optic nerve. The crystals obscure the underlying retina but usually do not affect vision.

Management

• No treatment usually recommended.

• Consider pars plana vitrectomy if particles become so severe that they affect vision or interfere with the diagnosis or treatment of retinal disorders; should be performed by a retina specialist.

Persistent Hyperplastic Primary Vitreous (Persistent Fetal Vasculature Syndrome)

Definition

Sporadic, unilateral (90%), developmental anomaly with abnormal regression of the tunica vasculosa lentis (hyaloid artery) and primary vitreous. Possibly due to abnormality of PAX6 gene.

Symptoms

Decreased vision; may have eye turn.

Signs

Leukocoria, papillary strands, strabismus, microphthalmos, nystagmus, pink-white retrolenticular/intravitreal membrane often with radiating vessels, “inverted Y” fibrovascular stalk emanating from optic nerve, Mittendorf dot; lens is clear early but becomes cataractous; associated with shallow anterior chamber (AC) (more shallow with age), elongated ciliary processes extending toward membrane, large radial blood vessels that often cover iris; may have angle-closure glaucoma (see Chapter 6), vitreous hemorrhage, or retinal detachment.

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FIGURE 9-5 Persistent hyperplastic primary vitreous with fibrovascular stalk emanating from the optic disc.

Differential Diagnosis

Leukocoria (see Chapter 7).

Evaluation

• Complete ophthalmic history and eye exam with attention to tonometry, lens, and vitreous; Hruby lens, noncontact biomicroscopic or contact lens fundus exam, and ophthalmoscopy.

• B-scan ultrasonography if unable to visualize the fundus.

• Check orbital computed tomography (CT) scan or magnetic resonance imaging (MRI) for intraocular calcifications.

• Visual evoked potential (VEP) useful to decide whether to operate or not.

Management

• Correct any refractive error.

• Retinal surgery with pars plana vitrectomy, lensectomy, cautery to fibrovascular stalk, and membrane peel advocated early (within first few months of life); lens-sparing surgery considered for patients with clear lenses and eccentric stalks; should be performed by a retina specialist. Contraindications to surgery include severe microphthalmia and clear media with severe retinal dysplasia.

• Nd : YAG laser vitreolysis of traction from optic nerve and peripapillary retina.

• Patching/occlusion therapy for amblyopia (see Chapter 12).

Prognosis

Visual outcomes depend on degree of maldevelopment; poor without treatment especially with posterior involvement secondary to glaucoma, recurrent vitreous hemorrhages, and eventually phthisis; earlier treatment improves prognosis.

Posterior Vitreous Detachment

Definition

Syneresis (liquefaction) of the vitreous gel that causes dehiscence of the posterior hyaloid from the retina and collapse of the vitreous toward the vitreous base away from the macula and optic disc. Can be localized, partial, or total.

Epidemiology

Most commonly caused by aging (53% by 50 years old, 65% by 65 years old); by age 70, majority of the posterior vitreous is liquefied (synchysis senilis); female predilection. Occurs earlier after trauma, vitritis, cataract surgery, neodymium : yttrium–aluminum–garnet (Nd : YAG) laser posterior capsulotomy, and in patients with myopia, diabetes mellitus, hereditary vitreoretinal degenerations, and retinitis pigmentosa.

Symptoms

Acute onset of floaters and photopsias, especially with eye movement.

Signs

Circular vitreous condensation often over disc (Weiss ring), anterior displacement of the posterior hyaloid, vitreous opacities; may have vitreous pigment cells (tobacco dust), focal intraretinal, preretinal, or vitreous hemorrhage.

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FIGURE 9-6 Circular Weiss ring seen over the optic nerve in the midvitreous cavity.

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FIGURE 9-7 Horseshoe-shaped posterior vitreous detachment seen over the optic nerve in the midvitreous cavity.

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FIGURE 9-8 Pigmented cells in the anterior vitreous are a sign of a retinal break.

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FIGURE 9-9 Spectral domain optical coherence tomography of posterior hyaloidal face in a patient with impending posterior vitreous detachment.

Differential Diagnosis

Vitreous hemorrhage (see below), vitritis, fungal cyst.

Evaluation

• Complete ophthalmic history and eye exam with attention to anterior vitreous; Hruby lens, noncontact biomicroscopic or contact lens fundus exam, and ophthalmoscopy with a careful depressed peripheral retinal examination to identify any retinal tears or holes.

Management

• No treatment recommended.

• Instruct patient on retinal detachment warning signs: photopsias, increased floaters, and shadow or shade in peripheral vision/visual field defect; instruct patient to return immediately if RD warning signs occur to rule out retinal tear or detachment.

• Repeat dilated retinal exam 1–3 months after acute posterior vitreous detachment to rule out asymptomatic retinal tear or detachment.

• Treat retinal breaks if present (see Chapter 10).

Prognosis

Good; 10–15% risk of retinal break in acute, symptomatic posterior vitreous detachments; 70% risk of retinal break if vitreous hemorrhage is present.

Synchesis Scintillans

Golden brown, refractile cholesterol crystals that are freely mobile within vitreous cavity; associated with liquid vitreous, so the crystals settle inferiorly which is the most dependent area of the vitreous body. Rare, unilateral syndrome that occurs after chronic vitreous hemorrhage, uveitis, or trauma.

Vitreous Hemorrhage

Definition

Blood in the vitreous space.

Etiology

Retinal break, posterior vitreous detachment, ruptured retinal arterial macroaneurysm, juvenile retinoschisis, familial exudative vitreoretinopathy, Terson’s syndrome (blood dissects through the lamina cribrosa into the eye due to subarachnoid hemorrhage and elevated intracranial pressure, often bilateral with severe headache), trauma, retinal angioma, retinopathy of blood disorders, Valsalva retinopathy, and neovascularization from various disorders including diabetic retinopathy, Eales’ disease, hypertensive retinopathy, radiation retinopathy, sickle cell retinopathy, and retinopathy of prematurity.

Symptoms

Sudden onset of floaters and decreased vision.

Signs

Decreased visual acuity, vitreous cells (red blood cells), poor or no view of fundus, poor or absent red reflex; old vitreous hemorrhage appears gray-white.

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FIGURE 9-10 Vitreous hemorrhage obscures the view of the retina in this diabetic patient. Gravity has layered the blood inferiorly.

Differential Diagnosis

Vitritis, asteroid hyalosis, pigment cells, pars planitis.

Evaluation

• Complete ophthalmic history and eye exam with attention to visual acuity, tonometry, noncontact biomicroscopic or contact lens fundus exam, and careful ophthalmoscopy with a depressed peripheral retinal examination to identify any retinal tears or holes.

• B-scan ultrasonography to rule out retinal tear or detachment if unable to visualize the fundus.

Management

• Conservative treatment and follow for resolution of vitreous hemorrhage, unless associated with a retinal tear or hole which needs to be treated immediately (see Chapter 10).

• Bedrest and elevation of head of bed may settle hemorrhage inferiorly to allow visualization of fundus.

• Avoid aspirin and aspirin-containing products (and other anticoagulants).

• Consider pars plana vitrectomy if there is persistent idiopathic vitreous hemorrhage for > 6 months, nonclearing diabetic vitreous hemorrhage for > 1 month, intractable increased intraocular pressure (ghost cell glaucoma), decreased vision in fellow eye, retinal tear/hole, or retinal detachment; should be performed by a retina specialist.

• Treat underlying medical condition.

Prognosis

Usually good.

Vitritis

Inflammation of the vitreous characterized by vitreous white blood cells. Vitritis is a form of uveitis and is associated with anterior uveitis and more commonly intermediate or posterior uveitis; the degree of vitritis is graded on a 1 to 4 scale depending upon how limited the view of the retinal structures is (i.e., 1+ = few cells with mild obscuration of retina; 2+ = nerve and vessels visible; 3+ = only nerve and large vessels visible; 4+ = nerve and vessels not visible). It is important to distinguish vitritis from other types of cells in the vitreous cavity such as red blood cells (vitreous hemorrhage), pigment cells (retinal tear), and tumor cells (lymphoma, retinoblastoma, choroidal melanoma). The underlying etiology of the inflammation must be determined so that appropriate treatment can be given (see Uveitis sections in Chapters 6 and 10).