Central Serous Chorioretinopathy
Central serous chorioretinopathy is a retinal disorder which affects the macula. It is an “idiopathic disorder”, which means that the precise cause is unknown. Central serous is associated with an elevation (or detachment) of the macula, due to leakage of fluid. The leakage occurs through a defect in the layer under the macula, known as the retinal pigment epithelium. The retinal pigment epithelium (RPE) is a single-celled layer that lies between the retina and the choroids, a richly vascularized tissue. This RPE normally serves to prevent fluid from the choroidal blood vessels from leaking under the macula. In central serous chorioretinopathy, this fluid barrier is disturbed leading to accumulation of fluid which elevates the macular detachment, which in turn, distorts vision.
Clinical Findings
Patients usually present with a disturbance in central vision. On clinical examination, the ophthalmologist may find one or more small blister-like elevations in the macula or underlying RPE. Occasionally patients are asymptomatic, simply because the bubble of fluid does not involve the center of the. Signs of previous detachments of the retina can often be detected clinically.
An important part of the diagnosis of central serous chorioretinopathy relies on the fluorescein aniogram. In the typical case, a leak can be demonstrated at the level of the retinal pigment epithelium as the fluorescein dye gradually accumulates under the macula. This is the hallmark angiographic feature of the disorder in its classic form. The leaks will vary, depending on the duration of the detachment and the nature of the fluid.
Clinical Features and Demographics
The syndrome is much more common in men, who represent 85-90% of the cases. The onset is usually between the ages of 25 and 45, although, occasionally, a younger patient may be diagnosed with this disease. Older patients will continue to have signs of central serous chorioretinopathy when they develop it as a younger person, but some of the classic or typical features, will be modified by age-related changes.
Recent evidence has also shown a strong association between central serous and steroid use. Steroids taken orally, intravenously, by local injection, as skin creams or drops, as well as inhalers, have all been associated with this condition.
Prognosis
The prognosis for visual recovery from central serous is generally good. Usually, the pigment epithelial leak closes spontaneously, and the detachment resolves over a period of weeks to months. Most patients (greater than 90%) will retain vision of 20/30 or better in the affected eye. Although many patients may manifest subtle clinical findings in the opposite eye, most patients (greater than 80%) do not develop bilateral symptoms. Despite good visual acuity, some of these patients may still note some mild permanent abnormalities in the vision of the affected eye, such as decreased contrast, mild distortion and decreased night vision. Some patients will experience progressive atrophy of the pigment epithelium and severe vision loss, which is permanent.
Treatment
There is no known medical cure for this disorder. One known method to reduce the duration of the detachment, in an attempt to restore vision, is laser photocoagulation. Under fluorescein guidance, the leak can be identified and treated with laser. Although some ophthalmologists believe laser treatment should be carried out early in the course of the disease, most feel that a conservative approach in management should be entertained for a period of time before instituting treatment.
More recently photodynamic therapy has been used to treat leaks associated with central serous chorioretinopathy. It appears to be safe and effective. It is a modified laser that has a much lower incidence of causing scarring in the retina. The treatment approach should be carefully individualized with a retinal specialist since the manifestations and risk of treatment varies among patients.
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