A Randomized, Double-masked, Placebo Controlled Study of the Beneficial Effects of Eplerenone on Central Serous Chorioretinopathy

Central serous chorioretinopathy (CSC) is supposedly the fourth most common non-surgical retinopathy after age-related macular degeneration, diabetic retinopathy and branch retinal vein occlusion. The disease was first described by Albrecht von Graefe in 1866 as a 'recurrent central retinitis' and is nowadays commonly known as 'central serous chorioretinopathy', a term mainly coined by Donald Gass in the late 1960s.

Although the disease has been known for decades, the underlying mechanism is not yet fully understood. Numerous studies have shown an involvement of the retinal pigment epithelium (RPE) and the choroid which lead to accumulation of subretinal fluid with subsequent detachment of the neurosensory retina.

Among several assumed risk factors, high serum glucocorticoid levels seem to be related to the occurrence of CSC.

CSC typically affects young, male patients unilaterally and causes decreased and distorted vision, often associated with metamorphopsia, micropsia, dyschromatopsia and reduced contrast sensitivity. CSC can occur in an acute or chronic form. However, there is no agreement in the literature concerning the duration of the two forms. Some authors define CSC as chronic if there is persistent subretinal fluid for at least 6 months 11, others speak of chronic CSC when symptoms last longer than 3 months. In contrast there are studies where CSC is defined acute within the first 4 months. Spontaneously absorption is possible in up to 50% and normally leads to the recurrence of a normal visual acuity. Chronic CSC can result in a wide spread RPE damage and in a constantly reduction of visual acuity.

Structural changes in the retina and RPE have been found about 2 months after onset of the disease. Those changes can cause accumulation of photoreceptor outer segments, lead to consecutive atrophy of the photoreceptor cells and are associated with a loss of visual acuity.

Different concepts of treatment exist, but none of these may be deemed to be the golden standard. In the past few years several studies where CSC was treated with photodynamic therapy (PDT) or half-fluence PDT showed good visual outcomes and morphologic reconstitution. However, PDT is a destructive method which causes structural damage and can trigger other severe complications like choroidal ischemia and iatrogenic CNV. Furthermore, CSC is a self-limiting disease in many cases and physicians often hesitate to perform a relatively destructive therapeutical approach to treat a potentially self-limiting disease.

A newer, non-destructive therpeutical concept is the oral use of eplerenone a mineralocorticoid receptor antagonist. It is currently used in the treatment of hypertension and congestive heart failure. In the recent literature it was shown that eplerenone improved CSC and no serious adverse effects were observed in any case. However, no randomised controlled studies were performed comparing eplerenone with placebo to evaluate the clinical effect.