This article is more than 5 years old. Information may no longer be current.
Patient with latent prostate cancer reports history of decreased night vision
Click Here to Manage Email Alerts
An 81-year-old man was referred for decreased night vision for 8 months by his primary ophthalmologist. He felt that he had lost about 40% of his night vision over this time. He reported “sparkles” in his peripheral vision along with a “doughnut around his vision” in both eyes. He had some subjective decrease in his peripheral vision and chronic floaters in both eyes without recent changes.
The patient’s ocular history was remarkable for remote cataract surgery in both eyes and for being a glaucoma suspect. His medical history was notable for mild right carotid stenosis (50%), hyperlipidemia and prostate cancer treated with brachytherapy more than 5 years ago. Medications included lisinopril, ezetimibe and simvastatin (Vytorin, Merck/Schering-Plough Pharmaceuticals), folic acid, aspirin, vitamin D3 and vitamin B complex.
Best corrected visual acuity with refraction was 20/30 in both eyes. Intraocular pressure was 13 mm Hg in both eyes. Pupils were symmetric, with no afferent pupillary defect noted. Extraocular motility was full. On pseudoisochromatic color plate testing, the patient correctly named 7/10 plates in the right eye and 2/10 plates in the left eye. The anterior segment examination was remarkable for a posterior chamber intraocular lens in both eyes and rare cell in the left eye before dilation.
Dilated fundus examination revealed focal areas of retinal pigment epithelium atrophy and pigment clumping, mild vessel attenuation and mild optic nerve head fullness in both eyes (Figures 1a and 1b). There was evidence of rare old vitreous cells in the left eye. HVF 24-2 demonstrated marked superior constriction as well as some early inferior constriction in the right eye and diffuse peripheral constriction of the field in the left eye (Figure 2). Of note, HVF 24-2 from 6 months prior was full in both eyes.
|
Images: Goren JF, Hedges TR |
Optical coherence tomography (OCT) imaging through the optic nerve and macula demonstrated loss of inner and outer segment junction just outside the macular region and some optic nerve head fullness in both eyes (Figure 3). Electroretinography (ERG) testing demonstrated a reduction in both photopic and scotopic responses and decreased amplitudes in both the A and B waves (Figure 4). MRI imaging completed before the patient’s evaluation demonstrated focal signal abnormality in the brainstem at the superior cerebellar peduncle, venous angioma of the right cerebellar hemisphere, mild cerebral volume loss, and mild T2-weighted hyper-intensities within the periventricular and subcortical white matter that was non-specific and thought to be most likely related to small vessel ischemic disease.
Diffuse retinal degeneration
The differential diagnosis of diffuse retinal degeneration includes retinitis pigmentosa, cancer-associated retinopathy, toxic retinopathy, melanoma-associated retinopathy and vitamin A deficiency.
Retinitis pigmentosa would certainly be high on the differential diagnosis; however, the lack of a family history of retinal degeneration and the rapid time course of the progression of visual field loss make this somewhat less likely. Toxic retinopathy is typically caused by medications such as thioridazine, chloroquine and hydroxychloroquine; however, on additional medication review, there was no history of use of these agents. The patient had no history of melanoma to suggest melanoma-associated retinopathy; however, the patient had also not recently had a dermatology evaluation and was fair-skinned. There was no medical or dietary reason to suspect vitamin A deficiency. Given the patient’s remote history of prostate cancer, cancer-associated retinopathy (CAR) was felt to be high on the differential. A CAR antibody was sent off. The results of this were discussed with the patient’s primary care doctor, who initiated a work-up while the blood work was pending.
|
|
Discussion
Cancer-associated retinopathy typically presents with acute onset of rapid and progressive bilateral visual field loss, photopsia, photosensitivity and a ring scotoma. The time course of these symptoms is generally more rapid, on the order of months, compared with retinitis pigmentosa, which tends to be more gradual in progression. Signs of CAR on examination include attenuation of the retinal vessels; however, there is typically little pigmentary retinopathy. On visual field testing, there is often marked constriction, with an ERG typically affecting both the rods and cones. In later stages of the disease, OCT imaging may demonstrate severe macular thinning.
|
|
The average age at presentation of CAR is 65 years (range: 24 to 85 years). Women are affected twice as often as men. The time from cancer diagnosis to retinopathy is highly variable and may range from weeks to years. The retinopathy may also precede the discovery of the malignancy. The most common type of cancer associated with CAR is small cell lung cancer; however, CAR has also been associated with endometrial, breast, colon, prostate and hematological malignancies.
The mechanism of retinopathy is thought to be secondary to immune-mediated autoantibodies produced against the photoreceptors. There are several proteins that have been identified as targets of these antibodies, including recoverin, heat shock protein 70, enolase and neurofilaments. The tumor cell is thought to overexpress one of these proteins, which subsequently leads to antigen-presenting cell activation, immune response and the production of antibody to these proteins by activated lymphocytes. The binding of these autoantibodies to retinal cells then causes modulation of rhodopsin phosphorylation and a cascade of events ending in caspase-dependent apoptosis.
|
|
Treatment
Our patient was CAR antibody (anti-recoverin) negative; however, analysis was limited, as blood work was not sent to evaluate additional retinal antibodies that are also linked to this syndrome. Despite this, given the clinical suspicion, the patient underwent a thorough work-up, including a CT scan of the chest/abdomen/pelvis, which demonstrated a focal area of adenopathy within the perirectal space suspicious for malignancy. Subsequent CT-guided biopsy of this lymph node revealed small cell carcinoma. Our patient was then presented to the tumor board by his oncologist and a decision was made to initiate chemotherapy with carboplatin/VP-16. After three cycles of chemotherapy, on follow-up visit with the oncologist, the patient reported improvement in his visual symptoms with decrease in the sparkling sensation and no additional loss of night vision. His primary ophthalmologist reported that his visual fields have since stabilized.
Jordana F. Goren, MD, MS, and Thomas R. Hedges III, MD, can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111. Phone: (617) 636-4219. Fax: (617) 636-4866. Website: www.neec.com. Disclosure: Drs. Goren and Hedges did not report any relevant financial disclosures.
For more information:
- Adamus G. Autoimmun Rev. 2009;8(5):410-414.
- Hooks JJ. Clin Diagn Lab Immunol. 2001;8(5):853-858.
- Khan N. Semin Ophthalmol. 2006;21(3):135-141.
- Maeda T. Invest Ophthalmol Vis Sci. 2001;42(3):705-712.
- Matsubara S. Br J Cancer. 1996;74(9):1419-1422.
- Polans AS. Proc Natl Acad Sci U S A. 1995;92(20):9176-9180.
- Salgia R. Lung Cancer. 1998;22(2):149-152.
- Yanoff M. Ophthalmology. 3rd ed. Philadelphia: Elsevier; 2009.