Ординатура / Офтальмология / Английские материалы / Clinical Medicine in Optometric Practice_Muchnick_2007

from a compatible donor. Immunosuppression aids recovery in approximately half of cases.

Fanconi’s syndrome is congenital AA. The disease can best be described as severe pancytopenia-depression of the hemoglobin, WBC, and platelets, or any combination thereof, within the first 6 weeks of life. In addition to retinal findings of flame-shaped hemorrhages, associated with thrombocytopenia, a platelet count of less than 20,000/dl is usually present. Patients may also be seen with congenital cataracts.

Hemoglobinopathies

These disorders of the red blood cell affect the structure, function, or production of hemoglobin. Hemoglobin functions to deliver oxygen to tissues and any alteration in this molecule can produce anemia. Such alterations include RBC structural changes, RBC death, and abnormal oxygen-carrying capability.

The prototypical hemoglobinopathy is sickle-cell anemia (SCA). A single mutation in the beta-globulin gene results in the formation of fibrous polymers that causes a gelatinous erythrocyte membrane. Under anoxic conditions, sickle cell hemoglobin is relatively insoluble, and the molecules accumulate in parallel rows within the red cell. The stiffened RBC membrane causes the cell to assume a sickle shape. The sickled cell cannot easily pass through the small capillary lumen and it tends to stick to endothelial walls. This results in microvascular occlusion and RBC destruction. Tissue ischemia results from clogged capillaries and produces painful episodes characterized by fear, anxiety, and muscular pain. These painful crises last from hours to days and may occur anywhere in the body.

Tissue destruction may lead to end-organ destruction. Infarction of the skin, spleen, CNS, bones, liver, and lungs may occur. SCA may cause renal necrosis and renal failure. Stroke may also occur and is usually the result of cerebral hemorrhage rather than infarct. Sickling of red cells with abnormal hemoglobin occurs under conditions of decreased oxygen tension, a condition seen more often in organs with more sluggish circulation, such as the spleen, gastrointestinal (GI) tract, lungs, joints, and bones.

The origin of the sickled gene can be traced to the African continent. Data suggest that this mutation of the hemoglobin chain protected those affected from malaria infestation. Genetically, valine is substituted for glutamic acid, causing a structural deformity of the hemoglobin chain. This structural abnormality causes the hemoglobin chain to form crystals, accounting for the sickle-shape red blood cell that leads to intravascular clotting.

The frequency of the sickle cell gene is approximately 12% in the American population. It encompasses individuals of African American, Mediterranean, Middle Eastern, and Southeast Asian ancestry in descending order of frequency. Normal adults inherit two genes that code for normal adult hemoglobin (AA). The abnormal hemoglobins are inherited as autosomal dominants; consequently, individuals who have at least one gene coding for normal adult hemoglobin (A) therefore have the trait (AS only, known as sickle cell trait, and being heterozygous with 50% hemoglobin C or S) and rarely have complications. Patients with hemoglobin SS (homozygous with both parents having the disease and classified as sickle-cell

anemia), manifest the worst systemic symptomology but not the most severe ocular complications. When the sickled hemoglobin is combined with other abnormal hemoglobins (thalassemia, sickle hemoglobin C, hemoglobin E), ophthalmic pathology may be expected in the second decade of life. Patients with sickle cell hemoglobin C and S-beta thalassemia hemoglobinopathies exhibit the most severe ocular complications.

Orbital involvement of SCA includes the symptom of pain and the sign of proptosis. SCA causes a retinopathy by occlusion of the retinal vessels. This results in hemorrhage and eventual retinal neovascularization in a “sea fan” appearance. Repeated vitreous hemorrhages may result in fibrovascular scarring and retinal detachment. The ophthalmic pathologic changes can be categorized as follows:

1.Superficial changes, as evidenced by commashaped vessels seen in the conjunctiva. These background changes are nonproliferative, and are evidenced by venous tortuosity, vascular loops, schisis, cotton-wool spots, and angioid streaks.

2.Nonproliferative retinal hemorrhages that may be preretinal, intraretinal, or subretinal in location. As these hemorrhages resolve, various signs occur depending on the depth of retinal involvement. These findings include salmon patches (retinal hemorrhages with partially degenerated blood), retractile deposits (iridescent spots that represent old, resolved, subinternal limiting membrane hemorrhage with hemosiderin deposition), and black sunbursts (resulting from a retinal hemorrhage that extends to the subretinal space and causes secondary retinal pigment epithelial hyperplasia with migration into the retina in a perivascular location). The nonproliferative findings rarely affect vision and consequently require no treatment.

3.A proliferative retinopathy that usually affects the retinal periphery and, because of its progressive nature, is associated with visual loss.

Proliferative SCA consists of the following five stages:

Stage I: Peripheral arteriolar occlusions Stage II: Peripheral AV anastomoses

Stage III: Neovascularization in a “sea-fan” appearance Stage IV: Vitreous hemorrhage

Stage V: Traction or rhegmatogenous retinal detachment

The diagnosis of abnormal hemoglobin may be suggested by abnormal red-cell morphology (sickle cells, target cells, hemoglobin crystals in the cytoplasm). The diagnostic clinical test is hemoglobin electrophoresis, which not only confirms the presence of abnormal hemoglobin but also quantitates the specific amounts. This quantitation can frequently aid in the clinical and prognostic decisions in this disease. SCA is always suspected in an anemic patient with ischemic pain,

and hemoglobin electrophoresis and sickling tests confirm the diagnosis.

The treatment of SCA includes narcotic analgesia to control the painful crises. Routine optometric examinations are necessary to evaluate and monitor any SCA retinopathy. Photocoagulation as well as retinal surgery has been used to stabilize the retinal lesions associated with SCA. Peripheral neovascularization (seafans) has been reported to spontaneously regress 50% of the time. The proliferative findings are most consistently associated with individuals who have hemoglobin C (AC, SC, CC). Long-term medical care is necessary to manage the typical causes of SCA morbidity: end-stage renal failure and pulmonary hypertension.

The thalassemias are syndromes that result from genetic defects that produce unstable globin chains that cause damage to the RBC membrane. This problem leads to hemolysis. Two forms of thalassemia exist: beta-thalassemia major (Cooley’s anemia) and alphathalassemia.

Beta-thalassemia is a severe form of the disease and is usually fatal in childhood. It is diagnosed by the findings of microcystic, hypochromic RBCs combined with other specific test results. The disease may present as a homozygous beta-thalassemia or a heterozygous form. This type of patient has beta-thalassemia trait, which is usually free of symptoms. Genetic counseling is of utmost importance to these individuals. Therapy for betathalassemia major includes frequent transfusions and iron chelation (to remove excess iron). Homozygous alpha-thalassemia results in intrauterine demise. The heterozygous form should be suspected in Asians with hypochromic, microcytic anemia without iron deficiency. Special testing is necessary in these individuals.

Chronic Myeloproliferative Disorders

One of the most common chronic myeloproliferative disorders is polycythemia vera. This disorder is characterized by overproduction of one of the formed elements of the blood. An increase occurs in RBCs, granulocytes, and platelets. The etiology is unknown, although it appears related to stress, high altitude, chronic lung disease, tumors, and kidney disease. Diagnosis is made on review of the hematocrit level. The elevation in the mass of RBCs leads to systemic hypertension and venous thrombosis. Blood viscosity increases, causing retinal hemorrhaging, transient blindness (amaurosis fugax), and blurred vision. The retinal pathology is associated with red cell counts in excess of 6 million/mm3, and is characterized by marked dilation and tortuosity of the retinal vessels with severe stasis retinopathy. Superficial and deep retinal hemorrhages may occur with associated swelling of the optic nerve head. Ultimately there may be retinal venous and artery occlusion. Uric acid levels increase causing gout and pruritus. Treatment

makes use of phlebotomy, radioactive phosphorus, and alkylating agents, to reduce the hyperviscosity of the blood.

Blood viscosity may also be influenced by plasma proteins and produce a range of disorders known as serum protein abnormalities. Three categories of plasma proteins circulate with the liquid fraction of blood: albumin, fibrinogen, and several types of globulins. Diseases associated with protein abnormalities can be primary or secondary (Table 15-2). The ophthalmic pathology is that of a congestive retinopathy. Waldenström’s macroglobulinemia and myeloma have been associated with this pathology. The laboratory findings, in addition to a variable level of anemia, are an abnormal protein electrophoresis with the characteristic “M” protein spike.

Coagulopathies

The flow of blood has a regulatory mechanism to retard or stop the egress of the precious fluid. This system is called the coagulation or clotting system. The production, destruction, and quality of its components and the number and quality of the circulating platelets regulate bleeding. The clotting cascade is a complex scheme that explains the sequential steps in the intrinsic and extrinsic clotting system. A disorder at any point in this system is called a coagulopathy, and examples include hemophilia, hypercoagulable syndromes, and disseminated intravascular coagulation.

Hemophilia

The more severe coagulopathies are usually sex-linked and therefore have their greatest expression in males (hemophilia A and B). The more frequent bleeding dia-

theses are associated with deficiencies of those factors made by the liver. Accurate diagnosis requires the interpretation of the prothrombin time, activated partial thromboplastin time, platelet count, and specific assays where indicated. Treatment is with specific replacement of the factor by human blood products or synthetic derivatives. Intraocular or extraocular hemorrhage may occur spontaneously, by trauma, or during surgery. Bleeding most commonly occurs 24 to 36 hours after the trauma. Most hemorrhages are self-limiting, but some require treatment. Retrobulbar hemorrhage may cause central retinal artery occlusion.

Hypercoagulability Syndromes

In the past two decades the clinical presentation of hypercoagulable syndromes has been better described. The circulation of activated clotting factors could result in uninhibited intravascular clotting (usually venous). The critical inhibitors of this coagulation are antithrombin III, protein C, and protein S. Congenital deficiency states have been associated with ophthalmic thrombotic complications (1 in 500,000 live births).

Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC) is a dynamic hematologic state in which, because of the underlying processes, clotting occurs throughout the body, with consumption of clotting substances in excess of the body’s ability to replenish the consumed substances. DIC is characterized by activation of the coagulation system, consumption of coagulation proteins and platelets, and thrombic occlusion of the small blood vessels. DIC is usually an acute emergent process associated with thrombocytopenia, prolonged prothrombin time, prolonged activated partial

Unexplained edema or ascites

Suspected liver disease

Collagen diseases, sarcoidosis

Unusual susceptibility to infections

CLL, malignant lymphoma

Unexplained proteinuria

Evidence of plasma cell neoplasms (e.g., bone pain, frequent infections, elevated sedimentation rate, rouleaux formation, proteinuria, or osteolytic skeletal lesions)

Amyloidosis

Hypoalbuminemia

Hypoalbuminemia frequent; hyperglobulinemia suggests cirrhosis or chronic active hepatitis

Polyclonal hyperglobulinemia Hypogammaglobulinemia or agammaglobulinemia

Hypogammaglobulinemia or, rarely, IgG or IgM M components Albumin or a mixture of all serum proteins is found with uri-

nary tract infections or the nephrotic syndrome; homogeneous urine proteins that migrate in the globulin region are usually indicative of plasma cell neoplasms secreting free light or heavy chains.

Serum or urinary monoclonal protein, with reduced normal immunoglobulins and hypoalbuminemia

Monoclonal serum or urinary proteins frequent

thromboplastin time, low fibrinogen level, and fragmented RBCs on the peripheral smear. Clinically, widespread hemorrhage and ischemic tissue damage is present. No test is available to confirm the diagnosis. With a rapidly evolving clinical picture and generalized bleeding, however, a high index of suspicion is the single most important factor in proper diagnosis and treatment. Although the recommendations for treatment are varied, none is successful unless the underlying mechanism is controlled. Ocular involvement in DIC can include retinal pigment epithelium necrosis and serous retinal detachments resulting from thrombic occlusion of the choriocapillaris and larger choroidal vessels. Visual loss occurs when the submacular choroid is affected. DIC may be confused with TTP, because both entities are characterized by thrombocytopenia. Only in DIC, however, does widespread activation of coagulation and fibrinolysis exist. Coagulation tests are therefore abnormal in DIC and are unaffected in TTP.

Leukemia

This group of diseases is characterized by infiltration of the blood and bone marrow by neoplastic blood cells, and is a malignancy of the blood-forming organs. Malignant proliferation of WBCs or any of their developmental forms is called leukemia. Eye signs occur in 50% to 70% of cases of leukemia. Known as myeloid leukemia, this disorder can be seen as acute or chronic forms. Acute myeloid leukemia (AML) is caused by radiation, chemical exposure, or hereditary factors. Two forms exist: the lymphoid (L1, L2, and L3) and nonlymphoid (ANLL, M1-M7) varieties (Table 15-3). Symptoms include fatigue, weakness, anorexia with weight loss, bleeding, HA, and bone pain. The mass

lesion associated with AML is a granulocytic sarcoma and is composed of leukemic cells. Clinical signs include anorexia, GI bleeding and enlarged spleen.

The initial presentation of AML may relate to a visual complaint. Ophthalmoscopic findings in cases of AML include retinal infiltrates and papilledema. The optic nerve head swelling can occur because of leukemic infiltration of the optic nerve. In fact, leukemic infiltrates may be seen additionally in the retina, choroids, or vitreous. Ocular infiltrates are associated with a poor prognosis for life when found with high WBC counts, and fulminant disease. Cranial nerve palsies may occur because of CNS leukemia. Emergent triage to a subspecialist conversant in the management of leukemia is paramount to the patient’s survival. Leukemia is an ocular emergency until proven otherwise. Treatment is aimed at complete remission (CR) and prolongation of survival. CR is achieved by combination chemotherapy. No cause has been found for chronic myeloid leukemia (CML), in which presenting symptoms are vague. CML affects the lymphoid or the myeloid cells. Patients complain of fatigue and weight loss, with a much more insidious onset than AML. Eventually, fevers occur with continued weight loss. The spleen is found to be enlarged on physical examination. Lab findings including the CBC and bone marrow tests demonstrate elevated WBCs. Treatment of CML involves a bone marrow transplant from an HLA-compatible donor. Both AML and CML may have an associated leukemic retinopathy. When found in the context of anemia, thrombocytopenia, and increased blood viscosity, retinal hemorrhages may occur in the posterior pole. These can be flame-shaped or dot-and-blot hemorrhages. In addition, Roth’s spots may occur in leukemia. The white area found central in a Roth spot is composed of platelets and fibrin.

198 CLINICAL MEDICINE IN OPTOMETRIC PRACTICE

Cotton-wool spots may also occur in leukemic retinopathy in the absence of systemic symptoms. Often the finding of cotton-wool spots motivates the eye examiner to order the systemic work-up that ultimately leads to the diagnosis of leukemia.

Lymphoma

Malignancies of the lymphoid cells always present as leukemia of the bone marrow and blood or as a lymphoma. A lymphoma is a solid tumor of the immune system. Lymphoid malignancies have been classified into three types by the World Health Organization: the non-Hodgkin’s lymphomas (B-cell and T-cell neoplasms), and Hodgkin’s disease. Lymphoma is the most common malignancy that infiltrates the optic nerve. Usually lymphomatous cells infiltrate the retrolaminar portion of the optic nerve. Visual analysis will confirm the presence of a relative afferent papillary defect, color and visual field defects, and a painless reduction of visual acuity, all on the involved side. Ophthalmoscopy may reveal disc edema caused by the infiltrative optic neuropathy. Radiotherapy can be used in the treatment of infiltrative optic neuropathy secondary to lymphoma

Hodgkin’s Disease

HD occurs at a rate of approximately 8000 cases per year in the United States. The most common presenting symptom is a nontender, palpable lymphadenopathy in the neck. Some patients exhibit fever, night sweats, and weight loss. Confirmation of the disease is made by lymph node biopsy. More than 90% of patients with HD are cured by extended-field radiotherapy, although chemotherapy is traditionally used first. This treatment is then followed by radiotherapy to the involved nodes.

ONCOLOGY Systemic Cancer

The Cancer Patient

The diagnosis of cancer, regardless of the type or prognosis, is often a life-altering experience for the patient. The patient often feels emotions of guilt, depression, and anxiety. The cancer patient often feels that they could have done something to prevent the disease, and their lifestyle is often forever altered.

Epidemiology of Cancer

In 2000 more than a million new cases of invasive cancer were diagnosed in the United States, and in the same year more than a half million patients died of some form of cancer. It is the second leading cause of death in the United States after heart disease. The incidence of cancer increases dramatically with age, the most significant

cancer risk factor. The leading cause of cancer deaths in both men and women is primary tumor of the lung. The second most common cause of cancer death in men is primary tumor of the prostate, and in women it is breast cancer. The third most common cause of cancer death is colorectal cancer, followed by pancreas and then, in men, lymphoma, and in women, primary tumor of the ovary. In men the most common form of cancer is primary tumor of the prostate (30%), followed by lung cancer (15%), colorectal cancer (10%), bladder cancer (6%), and lymphoma (5%). In women the most common form of cancer is primary tumor of the breast (30%), followed by lung cancer (12%), colorectal cancer (11%), endometrial cancer (6%) and ovarian cancer (4%).

Diagnosis of Cancer

The diagnosis of cancer mandates tissue biopsy because no noninvasive test can confirm the disease. Beyond prevention, successful management of cancer relies heavily on early and accurate diagnosis. Once identified, the extent of the disease is determined by defining its clinical stage.

Cancer Treatment

The most effective treatment of cancer is surgical excision, accounting for a 40% cure rate. At least 60% of all solid tumors, however, can have associated metastatic disease. Radiation therapy makes use of a characteristic of tumor cells making them more sensitive to the lethal effects of radiation than normal tissue cells. Chemotherapy uses chemicals to stimulate tumor regression or to slow tumor growth. Cancers considered possibly curable by chemotherapy include Hodgkin’s disease and certain lymphomas. Chemotherapy and radiation are both used to treat breast cancer, uterine carcinoma and small cell lung carcinoma. Advanced tumors poorly responsive to chemotherapy include melanoma and pancreatic cancer, renal, thyroid, and prostate carcinoma.

Side Effects of Cancer Treatment

Cancer therapies are toxic and produce physical and psychosocial challenges. Side effects of treatment include pain, nausea, vomiting, anorexia, weight loss, and recurrent infections. Cancer therapy must address these unacceptable, life-threatening side effects. Chemotherapy commonly causes nausea and vomiting. Prochlorperazine is given to prevent emesis and may be enhanced by intravenous dexamethasone. Agents may be given to prevent emesis because this is more effective than alleviation of vomiting once it has started.

Goals of Cancer Treatment

Ideally, a complete response to therapy occurs wherein the disease completely resolves. Progressive disease is established on the appearance of a new lesion or an increase in the size of the tumor of more than 25%.

Tumor Markers

Tumor markers are used in some cases to gauge response to therapy. These markers include hormones, oncofetal antigens, enzymes, and tumor-associated proteins. For example, catecholamines are hormones used in the detection of pheochromocytoma, and prostate-specific antigen (PSA) is a prostate cancerassociated protein.

Cancer Pain

Cancer-related pain is most often the result of invasion of the bone, nerves, or mucous membranes, by the tumor itself. Surgical or medical procedures related to cancer treatments account for approximately one fifth of all cancer-related pain. Mild pain is often controlled with NSAIDs, acetaminophen, or aspirin. Persistent or severe pain may mandate the use of codeine, oxycodone, or morphine. Nutritional advice and psychosocial support are both essential elements in the successful management of cancer patients, and should be offered in all cases of the disease.

Cancer Prevention

Cancer prevention is a field that identifies biologic, genetic, and environmental influences that stimulate and promote cancer production, and develop interventional strategies to manipulate and minimize the impact of these factors.

Risk Factors

The most avoidable cancer risk is smoking. The optometrist can and should counsel any known patient who smokes on the benefits of smoking cessation. Changes in diet may reduce the risk of cancer. Patients should be counseled to lower dietary animal fat intake and to increase consumption of foods rich in anticarcinogenic compounds including the phenols, flavones, and fiber found in fruits, nuts, and vegetables. Avoidance of sun exposure and specific carcinogenic chemicals including asbestos, arsenic, benzene, and vinyl chloride, may reduce the risk of cancer. In addition, certain infections, including Epstein-Barr virus, hepatitis, HIV/AIDS, and Helicobacter pylori are associated with specific cancer types. In the spring of 2006, a vaccine was approved to prevent the viral etiology of cervical cancer.

Intraocular Tumors

Metastatic tumors to the eye are increasing in incidence because of the increasingly prolonged survival of cancer patients. The most common form of intraocular malignant tumor is metastatic cancer. The incidence of ocular metastases is approximately 300,000 per year. These tumors are often not found because they occur

primarily in terminally ill patients who do not seek optometric evaluation. Only approximately 5% of ocular tumors are considered primary to the eye. The remaining 95% occur by metastasis or direct extension. The nonmetastatic ocular pathophysiology is that of infection (Box 15-1). Host immunosuppression caused by the underlying malignancy predisposes the host to opportunistic infections that are primarily viral, fungal, or protozoan. These infections are extremely difficult to treat and invariably need the recommendations of an infectious disease specialist to avoid catastrophic blindness (Box 15-2).

Metastases to the eye occur only in adults and are more common in women because of breast cancer, and in men because of lung cancer (Table 15-4). In children, metastases are very rare. The most common tumor to metastasize to the eye is the carcinoma. In 90% of cases of intraocular metastasis, the primary site is found by clinical evaluation.

The macula is the most common site in the eye for metastatic tumor involvement. Metastasis to the retina, optic disc, or vitreous is rare. Macular involvement demonstrates a painless loss of vision and the discovery of a choroidal tumor in the posterior pole. The

BOX 15-1

OPHTHALMIC MANIFESTATIONS OF SYSTEMIC CANCER

Metastatic

Orbit

Ocular

Anterior segment

Posterior segment

Nonmetastatic

Infections

Treatment-related complications

Remote effects (paraneoplastic)

BOX 15-2

COMMON OCULAR INFECTIONS IN CANCER PATIENTS

Anterior Segment

Herpes zoster (iritis, keratitis)

Herpes simplex (iritis, keratitis)

Posterior Segment

Toxoplasmosis (retinitis)

Cytomegalovirus (retinitis)

Herpes simplex (retinitis)

Fungal infections

Candida species (retinitis)

Mucormycoses (vasculitis)

Endogenous Endophthalmitis

Bacterial

Fungal

TABLE 15-4 MOST COMMON PRIMARY CANCERS IN CHOROIDAL METASTASES

metastatic tumor of the choroids is typically single or multiple creamy-yellow lesions deep to the retina. No inherent pigment is present, but the overlying RPE may be disrupted. An associated nonrhegmatogenous retinal detachment may be associated with the tumor. Metastatic tumors may be bilateral and multifocal. The diagnosis of metastatic choroidal tumor is aided by fluorescein angiography, ultrasonography, intraocular biopsy, and systemic evaluation. Treatment of choroidal metastatic tumor includes external beam radiotherapy and chemotherapy. Treatment of the primary tumor is usually associated with regression of the ocular metastases. The prognosis in patients with metastatic carcinoma to the choroid is generally quite good. The systemic prognosis is guarded.

Ocular Tumor Detection

Intraocular tumors, whether primary or the result of metastatic extension, may be suspected on the basis of the following six characteristics (Figures 15-2 and 15-3): 1. Increase in size. Suspicious lesions of the eye or adnexa may be visualized grossly or require diag-

FIGURE 15-2 ■ A preoperative view of a conjunctival tumor which was suspicious because of increasing size, discoloration (from normal conjunctival tissue), surrounding engorged blood supply, indistinct margins, distortion of surrounding conjunctiva and induced astigmatism causing a loss of visual function.

FIGURE 15-3 ■ The postoperative appearance of the same patient as in Figure 15-2. Biopsy revealed a primary conjunctival malignancy.

nostic techniques. These approaches include direct ophthalmoscopy, indirect ophthalmoscopy, stereoscopic ophthalmoscopy (with 60, 75, or 90 diopter lens and biomicroscope), and gonioscopy. Tumors of the ciliary body may be visualized by retroilluminating the sclera with a bright penlight placed near or on the limbus 180 degrees away from the suspected lesion. Whatever technique is used, the lesion must be described as well as possible, drawn, measured accurately, and, if possible, photographed. Photographic alternatives include standard slit-lamp or retinal cameras, stereoscopic cameras, digital photography and videography. The suspicious lesion should be remeasured at regular intervals. Growth raises the possibility that the lesion is malignant.

2. Discoloration. In general, a lesion is more suspicious for malignancy if it reveals a discoloration compared with the normal surrounding tissue. Discoloration is just one small piece of evidence that suggests a serious disorder; of course, many discolored ocular lesions are benign.

3. Neovascular growth. Vascular changes may occur to a greater degree within or overlying intraorbital tumors than in benign lesions. Any lesion that is associated with a dilation of surrounding normal vasculature (for example, on the conjunctiva) or is associated with neovascular growth should be evaluated for possible malignancy. Intraocular tumors may produce vascular abnormalities as visualized on fluorescein angiography. They may hyperfluoresce, hypofluoresce, or be “invisible” to the test, depending on the nature of the choroidal tumor.

4. Indistinct margins. In general, benign ocular tumors tend to have distinct margins, whereas malignant lesions have indistinct margins. This difference results from the malignancy growing and spreading through the surrounding tissue. The

tumor border may reveal both lateral spread and deep-tissue invasion.

5. Distortion of the surrounding tissue. A malignant tumor has a greater tendency to distort the normal tissue surrounding it than does a benign growth. Again, this is the result of lateral and deep spread of the malignancy through the tissues around it. Also, metastatic islands of spread may be detected visually around the main lesion.

6. Loss of function. In general, benign lesions cause little or no loss of normal organ function. Malignant tumors have a greater potential for interfering with ocular function. An iris melanoma may therefore cause a papillary anomaly; a ciliary body tumor may alter aqueous production and, hence, intraocular pressure; and a choroidal malignancy may be associated with a serous detachment and possible loss of vision.

Management of Ocular Malignancy

The management of both ocular metastases and primary ocular malignancies may include irradiation of the eye or surrounding tissue. Ophthalmic consequences may be immediate: dry eye, corneal ulceration, delayed cataract, neovascularization, ischemic ocular syndrome, neovascular glaucoma, and optic neuropathy secondary to radionecrosis. The prolonged survival of the cancer patient can also be associated with neuroendocrine syndromes related to tumor kinetics, toxins, antibodies, nutritional deprivation, or tumor hormone elaboration (Box 15-3). These are extremely unusual syndromes, and the occurrence of this pathology indicates a need for further evaluation for a primary cancer. The ocular complications from systemic or local (regional) chemotherapy are constantly increasing (Boxes 15-4 and 15-5). Complete medical history is the single most important factor in minimizing the impact of these drugs.

The ophthalmic consequences of systemic cancer require continuing dialogue and early referrals of the eye-care professional and the practicing oncologist. When they work together, the life and vision of the cancer patient may be significantly prolonged.

BOX 15-3

REMOTE EFFECTS OF CANCER IN THE VISUAL SYSTEM: VISUAL PARANEOPLASTIC SYNDROMES

Ocular

Optic neuritis

Photoreceptor (retinal) degeneration (melanoma, oat-cell carcinoma)

Oculomotor

Opsoclonus (breast cancer, lung cancer) Opsoclonus-myoclonus syndrome (neuroblastoma, thyroid,

breast)

Lambert-Eaton myasthenic syndrome

BOX 15-4

OCULAR COMPLICATIONS OF SYSTEMIC CHEMOTHERAPY

Lids

5-Fluorouracil (entropion) Vincristine (ptosis) Vinblastine (ptosis)

Conjunctiva (Conjunctivitis)

5-Fluorouracil Methotrexate Melphalan Cyclophosphamide

Lens (Cataract)

Busulfan

Corticosteroids

Mitotane

Optic Nerve (Optic Neuritis)

Vincristine

Cisplatin

Nitrosourea (BCNU)

Lacrimal System

5-Fluorouracil (ductal fibrosis)

Cornea (Keratitis)

Busulfan

Chlorambucil

Cytarabine

Uvea

BCG

Thiotepa

Retina

Mitotane

Tamoxifen (refractile deposits)

Chlorambucil (hemorrhage)

Cisplatin

Nitrosourea (BCNU)

BOX 15-5

OCULAR SIDE EFFECTS OF INTRAARTERIAL CHEMOTHERAPY

Intracarotid Nitrosourea

Local pain (eye, orbit)

Conjunctivitis

Keratitis

Disc edema

Optic neuritis

Ocular ischemia and neovascularization

Retinal degeneration (vasculitis)

Intracarotid Cisplatin

Optic neuritis Transient visual loss

Retinal degeneration, with characteristic photopic electroretinographic changes

Toxic neuroretinitis

Pigmentary changes in retina, constricted arterioles, pale nerve

202 CLINICAL MEDICINE IN OPTOMETRIC PRACTICE

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TERMINOLOGY

The presence of a skin lesion should prompt the examiner to make every effort to correctly describe it in appropriate dermatological terminology (Box 16-1). Lesions may be flat or elevated, and may be solid or filled with pus, fluid, or blood vessels.

Flat lesions of less than 2 centimeters are called macules, and they are typically colored. A classic example of a macule is a freckle. A larger, flat and colored lesion is called a patch. A patch is a large macule and a typical example is vitiligo.

Descriptors of raised skin lesions are based on size and content. The smallest elevated lesion, known as a papule, is less than a centimeter in size and is solid in nature. Unlike a macule, a papule is palpable. A typical example of a papule is the raised lesion characteristic of acne rosacea. If the papule is filled with keratin, then it is known as milia. If the small lesion is fluid filled it is

*Special thanks to David C. Bright, author of the dermatology chapter in the first edition of this book. Many of his photographs and tables are reprinted in this edition.

referred to as a vesicle (Figure 16-1). Vesicles are the translucent lesions produced in cases of contact dermatitis from exposure to poison ivy. If the small lesion is filled with pus, it is referred to as a pustule (Figure 16-2). These lesions are filled with leukocytes. Cysts are raised lesions filled with fluid or semisolid contents.

A nodule is a solid, elevated lesion, similar to a papule, but measuring from 1 to 5 centimeters in size. A bulla is a fluid-filled nodule. An elevated lesion larger than 5 centimeters is known as a tumor.

If the elevated lesion is larger than a centimeter and has a flat, plateau-like top, then it is referred to as a plaque. This is the typical lesion that characterizes psoriasis and eczema. If the plaque is erythematous, it is referred to as a wheal, and is caused by dermal edema.

A painless, elevated overgrowth of dilated and superficial blood vessels is known as telangiectasia.

DERMATOLOGICAL PROCESSES AND SYSTEMIC CONSIDERATIONS

Certain processes are unique to dermatological conditions, and their appearance aids in identification, diagnosis, prognosis and treatment. Most often, but not