Optometrists in a practice unaffiliated with a tertiary care center will rarely see patients ocular cancer, a disease that is both sight threatening and life threatening. Because it’s impossible to predict who will walk through your door, it’s necessary to remain vigilant for signs of ocular melanoma, basal cell carcinoma, ocular lymphoma and leukemia, as well as cancers that have metastasized to the eye.
Atlanta-Optometrists in a practice unaffiliated with a tertiary care center will rarely see patients ocular cancer, a disease that is both sight threatening and life threatening. Because it’s impossible to predict who will walk through your door, it’s necessary to remain vigilant for signs of ocular melanoma, basal cell carcinoma, ocular lymphoma and leukemia, as well as cancers that have metastasized to the eye.
“Most ocular melanomas are picked up by optometrists during routine eye exams, and prompt diagnosis is critical to survival,” says Optometry Times blogger Melanie Denton, OD, FAAO, MBA. Dr. Denton, who recently opened a practice in Salisbury, NC, gave a joint presentation on ocular oncology at SECO 2016 with Mark Dunbar, OD, FAAO, director of optometric services and optometry residency supervisor, Bascom Palmer Eye Institute, University of Miami Health System.
Ocular nevi are far more common than melanomas, but the challenge all eye practitioners face is distinguishing them. Lesion characteristics such as size, elevation, color, regularity of edges, and location should be evaluated. A typical nevus will be less than 3 mm elevation and 3 disc diameters in size with clearly defined margins and slate gray in color. Drusen also support the diagnosis of nevi.
If signs point to a flat choroidal nevus, it’s generally safe to take a photograph and then follow yearly, says Dr. Dunbar. With suspicious nevi, more frequent follow-up-every three to six months-would be appropriate.
If the lesion hasn’t changed after several follow-up visits, the period between exams can be lengthened to a year if you’re comfortable with that schedule. While there may be exceptions, a lesion that grows little, if at all, over an extended period is likely to be a nevus.
“If it’s been there a while, you can feel better about it,” Dr. Dunbar says.
A careful, thorough, routine eye exam remains the best way to find melanomas. Besides routine measures such as comprising pupillary dilation, slit lamp exam, and binocular indirect ophthalmoscopy, add steps such as standardized echography, which is highly accurate and reliable and can provide tissue differentiation and documentation of change in size between visits, if warranted by the initial findings.
Choroidal melanomas are the most common primary malignant ocular tumor. The mnemonic TFSOM (To Find Small Ocular Melanomas) remains useful in distinguishing them from other lesions. This reminds the optometrist to evaluate thickness (lesions greater than 2 mm are suspicious), look for subretinal fluid, check for symptoms such as photopsia or vision loss, look for orange pigment overlying the lesion, and see if the margin is touching the optic nerve head.
TFSOM can be updated with “Using Helpful Hints,” two new characteristics that are predictive: ultrasonic hollowness and halo absence.
What should you say to patients if you find what appears to be a nevus? Would you run the risk of needlessly alarming a patient if you mentioned that you found a pigmented lesion, even if it doesn’t seem to be a melanoma?
“I’m a firm believer in telling patients just about everything I see,” says Dr. Denton. She says that this openness can be a practice builder with patients who like to be fully informed.
You may also find that the patient was told about an apparently benign lesion years earlier by another doctor, and this is reassuring because it suggests that the lesion is not new or rapidly growing and that your diagnosis is likely correct, Dr. Dunbar says.
For scenarios in which the diagnosis is confirmed to be choroidal melanoma, a number of treatment options are available. The treatment choices include:
• External beam radiation
• Plaque radiation
• Local excision/eye wall resection
While for many years enucleation was the only choice, this procedure is less common and currently used primarily for larger or complicated tumors. Close monitoring for growth is often a viable option for small melanomas.
With current molecular genetic testing, it is possible to better classify tumors and select the most appropriate treatment, Dr. Dunbar says. He says, though, that despite many advances in diagnostic technology, the causes of ocular melanoma are not fully understood.
Tumors may originate in the eye or metastasize from other organs. Among individuals in the U.S. whose death is attributed to cancer, five to 10 percent have microscopic metastatic intraocular cancer in at least one eye, according to Dr. Denton. In women, the malignancy most commonly originates in the breast, and in men, in the lungs. While the majority of patients found to have metastatic cancer to the eye have known disease elsewhere, in 25 percent of cases the ocular cancer is the initial manifestation to be identified.
“This is another reason why I believe in dilation for everybody, every year,” Dr. Denton says.
The only symptom of metastasis to the eye may be something as common as blurred vision, and patients often aren’t in any pain. On further examination, signs and symptoms might include golden yellow to yellowish-white round or oval lesions that are often associated with non-rhegmatogenous retinal detachment out of proportion to the size of the tumor. The list of differential diagnoses is long, and various diagnostic tests can be run to make a more precise diagnosis. Once the disease is identified, treatment should be coordinated with the medical oncologist, eye cancer specialist, and radiation specialist. Treatment options include chemotherapy, hormonal therapy, radiation therapy, and enucleation.
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Leukemia and lymphoma can cause an array of ocular manifestations; primary intraocular lymphoma is uncommon but may occur as either primary vitreoretinal or primary uveal lymphoma. Vitreoretinal lymphoma is bilateral in most cases. Diagnostic tests include fluorescein angiography, ultrasonography, fine needle aspiration, and incisional chorioretinal biopsy.
Because ocular leukemia and lymphoma are rare and may resemble each other, and there are also many differential diagnoses, identification is often difficult, and patients may be referred from specialist to specialist until a definitive answer is found, Dr. Dunbar says.
When one of these conditions is confirmed, systemic treatment is sometimes necessary. The vitreoretinal subtype of primary intraocular lymphoma may be associated with lymphomatous brain tumors that occur before, concurrently, or after the ocular manifestations, while the uveal subtype may be associated with visceral non-Hodgkins lymphoma in the abdomen or pelvis.
Patients with intraocular leukemia or lymphoma have bigger concerns than just the eye disease and should also be seeing an oncologist, Dr. Denton says.