Central Serous Chorioretinopathy (CSR)
Central serous chorioretinopathy is a retinal condition in which fluid elevates or “detaches” a small portion of the macula. The leakage is thought to come from the choroid, the layer of blood vessels beneath the retina, through a defect in the tissue layer separating the retina and the choroid called the retinal pigment epithelium or RPE. The RPE normally prevents fluid from the choroidal circulation from leaking under the retina and “pumps” excess fluid out of the retina. For unknown reasons, small pinpoint areas of the RPE become defective in one or both eyes. Fluid builds up under the retina in this area causing the distortion noted by patients. The leakage does not emanate from abnormal blood vessels such as in diabetes or abnormal forming blood vessels such as in macular degeneration.
CSR effects mostly men (85-90%) between the ages of 25 and 45. A second “peak” can occur later in life. Patients tend to be slightly hyperopic (far-sighted) but there is no association with any other eye or systemic disease. The disease tends to be found in patients with “Type A” personality, who tend to be more nervous or stressed. The disease can also be precipitated by oral, inhaled or nasal steroids, severe hypertension, pregnancy, antihistamine use, excessive alcohol use, collagen vascular disease, blood disorders, and organ transplant.
Patients present with a disturbance in central vision, either a gray zone, blind spot or distortion, termed a “metamorphopsia.” Typical focal areas of fluid elevation of the macula is noted. A test called a fluorescein angiogram helps to confirm the diagnosis. This test involves the injection of a vegetable dye into an arm vein. The dye helps to define the retinal circulation. Ocular Coherence Tomography, OCT, is also employed to measure the retinal thickness and obtain microscopic images of the area of concern. OCT helps the doctor “track” the course of the disease and give actual measurements of the retinal swelling. Digital pictures are taken and can record a characteristic leakage pattern found in CSR.
Laser treatment of the focal area of leakage identified on the fluorescein angiogram can reduce the duration of the focal retinal detachment. Most doctors will advise a course of observation as many cases resolve without treatment over 3-4 months. Laser treatment has rare risks of causing a noticeable blind spot in the central vision, inadvertent damage to the center of vision and bleeding. Prolonged fluid detachment can lead to irreversible degenerative changes. PDT can also be used to stop fluid leakage. Photodynamic therapy, PDT, involves injecting a dye into a patient’s arm vein that is selectively activated by “cool” laser light. The activated dye selectively destroys the abnormal, leaky blood vessels while leaving the overlying retina and nearby RPE unharmed.
Over 90% of CSR patients will maintain good reading vision of 20/30. Although CSR typically is found in both eyes, it is rarely, less than 20% symptomatic in the fellow eye. CSR recurs in 20-30% of all patients.