Ординатура / Офтальмология / Английские материалы / Clinical Pathways in Glaucoma_Zimmerman, Kooner_2001
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360 Glaucoma Associated with Systemic Disease
Future Considerations
Future studies might be able to document a direct influence of thyroid hormone on the regulation of aqueous flow.
GLAUCOMA ASSOCIATED WITH VASCULAR DISEASES
Definition
Ocular ischemia from ophthalmic artery occlusion and internal carotid artery disease, and retinal ischemia from central retinal vein occlusion (CRVO), central retinal artery occlusion (CRAO), branch retinal vein occlusion (BRVO), and cerebrovascular disease, have all been shown to cause glaucoma. For management, see Figure 16–3.
Epidemiology and Importance
Why Are Vascular Occlusive Diseases
of the Retina Important?
Ocular ischemia from occlusion of the ophthalmic artery and vascular occlusive disease of the retina can result in the development of rubeosis iridis and neovascular glaucoma. Ischemic CRVO is the most common cause of neovascular glaucoma in this group, with 60% of eyes developing iris neovascularization and 33% of eyes progressing to neovascular glaucoma. Ischemic hemispheric branch retinal vein occlusion (HRVO), nonischemic CRVO, and CRAO are all associated with the development of neovascular glaucoma to a much lesser extent. CRVO has been associated with systemic diseases such as cardiovascular disease, hypertension, and diabetes mellitus, systemic medications such as oral contraceptives and diuretics, and elevated IOP whether on an open-angle or angle-closure basis.53–59
Why Are Cerebrovascular Diseases Important?
Neovascular glaucoma may occur secondary to several cerebrovascular diseases such as carotid artery occlusive disease, giant cell arteritis, and Takayasu’s disease.56,60,61 Glaucoma secondary to elevated episcleral venous pressure has been associated with carotid-cavernous sinus fistulas and arteriovenous malformations (see Chapter 6).
Diagnosis and Differential Diagnosis
Screening gonioscopy in eyes with vascular occlusion, especially central retinal vein occlusion, is important to detect angle neovascularization before development of florid neovascular glaucoma.54,62 Carotid Doppler studies and echocardiogram further diagnose possible causes for ocular ischemia. In patients with symptoms of giant cell arteritis it might be necessary to obtain an erythrocyte sedimentation rate and a temporal artery biopsy.
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Figure 16-3. Management of a patient with glaucoma and vascular disease.
Treatment and Management
Treatment for glaucoma secondary to vascular occlusive disease of the retina is aimed at the underlying mechanism producing the glaucoma. Neovascular glaucoma is initially treated with cycloplegia, topical steroids, aqueous suppressants, and retinal laser photocoagulation. In patients with open angles and no evidence of neovascular glaucoma, elevated pressure in either eye should be reduced. Angle-closure glaucoma secondary to pupillary block requires an iridotomy. Non–pupillary block angle-closure glaucoma secondary to CRVO can in most cases be treated medically. Implantation of a glaucoma drainage device may be necessary if medical therapy fails to lower the IOP.
362 Glaucoma Associated with Systemic Disease
Prevention of neovascular glaucoma may be possible with prompt panretinal photocoagulation.54 Creating a chorioretinal anastomosis, applying recombinant tissue plasminogen activator, cannulating the retinal vein, transecting the posterior scleral ring, and using hemodilution have all been tried in the treatment of CRVO.63,64
Treatment of glaucoma secondary to cerebrovascular disease also is aimed at the underlying disease process. Carotid artery occlusive disease may produce neovascular glaucoma. Endarterectomy may be helpful in the management by preventing progressive infarction of ocular tissues. Therapy for glaucoma secondary to elevated episcleral venous pressure such as seen with arteriovenous malformations and carotid cavernous sinus fistulas is for the primary condition, and medical therapy is used to lower the IOP.
GLAUCOMA ASSOCIATED WITH COLLAGEN VASCULAR DISEASES
Definition
Openor closed-angle glaucoma can occur with keratitis, episcleritis, scleritis, and uveitis in association with several collagen vascular diseases, like juvenile rheumatoid arthritis (JRA), rheumatoid arthritis (RA), scleroderma, Wegener’s granulomatosis, systemic lupus erythematosus and relapsing polychondritis. For management, see Figure 16–4.
Epidemiology and Importance
How Often Are Collagen Vascular Diseases Associated with Glaucoma?
Secondary glaucoma due to chronic uveitis can be seen in 14 to 27% of children affected with JRA.65–69 Four percent of patients with scleritis secondary to rheumatoid arthritis have been found to have glaucoma.70
Neovascular glaucoma is a known complication of collagen vascular disease. It has been found in patients with scleroderma,71 Wegener’s granulomatosis,72 and systemic lupus erythematosus.73 Relapsing polychondritis has been associated with uveitic glaucoma.74 Angle closure secondary to uveal effusion and posterior scleritis has been documented in patients with systemic lupus erythematosus.75,76
Diagnosis and Differential Diagnosis
It is important to keep in mind that patients presenting with uveitic or neovascular glaucoma can suffer from potentially life-threatening conditions, such as collagen vascular diseases. Appropriate workup and prompt referral to a specialist might be lifesaving.
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Figure 16-4. Management of a patient with glaucoma and collagen vascular disease.
Treatment and Management
How Is Glaucoma Associated
with the Collagen Vascular Diseases Managed?
Treatment is directed at the underlying condition. The mainstay of therapeutics includes nonsteroidal antiinflammatory drugs and oral corticosteroids. Not
364 Glaucoma Associated with Systemic Disease
infrequently immunosuppressive or cytotoxic agents are necessary to control the disease.
The associated uveitis is treated with topical and/or local corticosteroids and cycloplegics. Occasionally systemic corticosteroids are needed if the inflammation is severe. The secondary glaucoma can be treated medically with aqueous suppressants and occasionally surgically if necessary.
Treatment of neovascular glaucoma is described in Chapter 14.
GLAUCOMA ASSOCIATED WITH RENAL DISEASE AND HEMODIALYSIS
Definition
What Is the Relationship Between Renal Disease
and Hemodialysis and Glaucoma?
Elevated IOP can be found in patients during and after hemodialysis,77 in patients following renal transplantation, and in patients with cystinosis.78 For management, see Figure 16–5.
Why Is the IOP Elevated in Some Patients During
and After Hemodialysis?
During hemodialysis for chronic renal failure, changes in serum osmolality result in fluctuation in IOP. As serum osmolality falls, changes in the osmolality of the intraocular fluids do not occur simultaneously. This results in the flow of free water into the eye raising the IOP. The greater the reduction in outflow facility, the larger the gain in IOP tends to be.79–81
However, if an increase of plasma colloid osmotic pressure is induced by removing fluid during hemodialysis, a drop in IOP can be noted.82,83
How Is Renal Transplantation Associated with Glaucoma?
Up to one-third of the patients with renal disease requiring transplantation develop elevated IOP postoperatively. This appears to be a steroid response related to the use of systemic steroids to prevent transplant rejection.
By What Mechanism Can Cystinosis Cause Glaucoma?
Cystinosis is a rare metabolic disease characterized by the deposition of cystine crystals in many parts of the body, in particular the kidney and the eye. Cystine crystals have been found in the uvea, conjunctiva, and cornea. A peripheral pigmentary retinopathy can develop in childhood. There has been one report of a young adult with cystinosis who developed an attack of acute angleclosure glaucoma. Pathology specimens of the iris revealed the presence of cystine crystals in the iris stroma and in the iris pigmentary epithelium. Cystine crystals were also found in this patient’s conjunctival stroma and conjunctival
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Figure 16-5. Management of patients with glaucoma and renal disease and hemodialysis.
mast cell granules. It was felt that the cystine crystals caused increased iris thickening and rigidity leading to angle closure.78
Epidemiology and Importance
Fluctuations of IOP occur during hemodialysis in patients with renal failure. During the first 2 hours of hemodialysis, a small decrease in IOP has been noted, followed by a rise in IOP after prolonged hemodialysis. An average rise in IOP of 7 mm Hg has been noted.84–86 However, it is not known if these changes are significant enough to cause glaucoma by itself in a nonglaucomatous eye.77,87–89 With newer hemodialysis techniques a significant change in IOP does not occur.90,91
366 Glaucoma Associated with Systemic Disease
Diagnosis and Differential Diagnosis
In patients with progressive glaucomatous optic neuropathy who are treated with hemodialysis, it might be helpful to monitor the IOP during and shortly after hemodialysis.
Treatment and Management
How Is Glaucoma Associated with Renal Disease and Hemodialysis Managed?
With current hemodialysis techniques, patients without a history of elevated IOP and/or decreased outflow facility are at a very low risk for developing glaucomatous optic neuropathy. On the other hand, eyes with uncontrolled glaucoma and seemingly good IOP control might have IOP spikes during or after hemodialysis. Acetazolamide has been found to prevent pressure spikes in this setting.92 However, acetazolamide has also been shown to cause severe metabolic acidosis in this setting.93
Steroid responders following renal transplantation can be successfully managed with medical therapy. Occasionally they will require glaucoma filtration surgery.
Is Glaucoma a Concern in Patients with Cystinosis?
Because cystinosis is a rare disease, relatively little is known about the treatment of secondary angle-closure glaucoma associated with this disease. Surgical trabeculectomy and iridectomy successfully treated the one case cited in the literature.78
GLAUCOMA ASSOCIATED
WITH HEMATOLOGIC DISORDERS
Definition
Which Are the Main Hematologic Disorders Associated with Glaucoma?
Glaucoma has been found to be associated with the hyperviscosity syndromes and with the sickle cell hemoglobinopathies. For management, see Figure 16–6.
How Do the Hyperviscosity Syndromes Produce
Glaucoma?
The hyperviscosity syndromes refer to a group of diseases that increase serum viscosity and subsequently decrease blood flow. The main clinical entities are polycythemia and the dysproteinemias. The reduction in blood flow results in dilation and tortuosity of the retinal veins. If a secondary central retinal vein
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Figure 16-6. Management of a patient with glaucoma and hematologic disorders.
occlusion occurs, neovascular glaucoma can develop.94,95 A 32-year-old man has been described who developed central retinal vein occlusion with resulting neovascular glaucoma after strenuous activity associated with dehydration.94
Does Blood Viscosity Play a Factor in the Etiology
of Primary Open-Angle Glaucoma (POAG)?
There are some studies that suggest blood hyperviscosity may play a role in the etiology of POAG.96,97 However, its role and significance is not fully understood.
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By What Mechanisms Can Sickle Cell
Hemoglobinopathies Produce Glaucoma?
The sickle cell hemoglobinopathies refer to a group of diseases in which normal adult hemoglobin A is transformed into hemoglobin S, C, or O (Arab) through exchange of a single amino acid in its molecule. The main clinical entities are sickle cell anemia (HbSS), sickle cell trait (HbAS), sickle cell C disease (HbSC), and sickle cell S/O(Arab) disease [HbSO(Arab)]. In sickle cell thalassemia (HbSThal) synthesis of the hemoglobin molecule is impaired.
Under hypoxic conditions the red blood cells in these disorders develop a sickle configuration occluding small blood vessels.98,99 Both proliferative and nonproliferative sickle cell retinopathy can develop in the peripheral retina mainly in patients with sickle cell C disease and sickle cell thalassemia. Central retinal artery occlusion and central retinal vein occlusion can occur in conjunction with sickle cell anemia. Neovascular glaucoma can develop secondarily in these patients, mainly in patients with HbSC.100,101 Elevation of IOP might also occur secondary to a blood clot obstructing Schlemm’s canal.102,103 In addition, vitreous hemorrhage secondary to sickle cell retinopathy can cause hemolytic or ghost cell glaucoma.
Introduction of sickle cell erythrocytes into the anterior chamber causes sickling and may result in a large rise of IOP.104–106 The erythrocytes in the aqueous tend to sickle at a higher rate than in the circulation due to a higher level of ascorbate,107 or a fall in the pH or PO2 secondary to the hyphema.108 The sickled red blood cells clog the trabecular meshwork and reduce the facility of outflow.109
Patients with the sickle cell hemoglobinopathies are particularly susceptible to central retinal artery occlusion with mild elevation in the IOP110 or trauma.111,112
Epidemiology and Importance
How Often Are the Hyperviscosity Syndromes Associated with Glaucoma?
In one series, 6 out of 15 young patients were diagnosed with blood hyperviscosity associated with central retinal vein occlusion.95
How Often Is Sickle Cell Disease Associated with Glaucoma?
Approximately 8 to 10% of African Americans are asymptomatic carriers of one gene for sickle cell disease, and 0.3% carry two genes and therefore have the full-blown disease.98,99 Individuals with sickle cell disease seem to be more prone to have retinal disease and neovascular glaucoma100; however, individuals with sickle cell trait are at a significantly higher risk to develop ocular complications after trauma.113
Is Sickle Cell Disease a Risk Factor for Chronic Open-Angle Glaucoma?
Sickle cell disease by itself does not seem to be a risk factor for chronic openangle glaucoma.114,115
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Diagnosis and Differential Diagnosis
Every black patient presenting with a traumatic hyphema should be screened for sickle cell disease.116
Treatment and Management
How Is Glaucoma Associated
with Hyperviscosity Syndromes Treated?
Neovascular glaucoma secondary to the hyperviscosity syndromes is treated with cycloplegics, topical steroids, aqueous suppressants, and retinal laser photocoagulation (see Chapter 14). Open-angle glaucoma secondary to thrombosis in Schlemm’s canal can be treated medically with aqueous suppressants.
How Is Neovascular Glaucoma in Patients with Sickle Cell Disease Treated?
Neovascular glaucoma secondary to the sickle cell hemoglobinopathies can be treated medically and with retinal laser photocoagulation. Proliferative sickle cell retinopathy is treated with laser photocoagulation to the involved quadrant; a central retinal artery occlusion or central retinal vein occlusion is treated with panretinal photocoagulation. Filtering surgery or implantation of a drainage device might be necessary (see Chapter 14).
How Is Ghost Cell Glaucoma Treated?
Ghost cell glaucoma secondary to associated vitreous hemorrhage is initially treated medically. However, a vitrectomy might be necessary to remove the cause of the ghost cell glaucoma, a nonresorbing vitreous bleed.
Is Glaucoma Secondary to Trauma Treated Differently in Patients with Sickle Cell Disease?
Certain precautions must be taken when treating elevated IOP secondary to hyphema in sickle cell hemoglobinopathy patients.116,117 Because mild elevation in IOP can produce irreversible visual loss, aggressive treatment of increased IOP in sickle cell hemoglobinopathy patients must be undertaken. Anterior chamber paracentesis might be warranted.110,118,119 However, certain medications should be avoided. Acetazolamide can increase the concentration of ascorbic acid in the aqueous, leading to increased sickling of red blood cells in the anterior chamber. Acetazolamide also acts on the kidneys, leading to a metabolic acidosis with secondary increased intravascular sickling and to increased blood viscosity due to its diuretic side effects. It also increases the ascorbic acid levels in the anterior chamber.107 Methazolamide is much less likely to cause these adverse side effects. Hyperosmolar agents may also increase serum viscosity, leading to vascular compromise in the eye. Epinephrine, apraclonidine, and brimonidine probably should be avoided due to their vasoconstrictive properties reducing anterior chamber oxygenation.120–122 In