Diuretics for central serous?

A small study found that patients treated with spironolactone for central serous retinopathy (CSR) were 7 times more likely to have resolution of CSR than the observe group.
What is spironolactone?
A diuretic, commonly used to treat hypertension and heart failure.
So how does that help with CSR?

This diuretic antagonizes the action of aldosterone at mineralocorticoid receptors.

What does that mean in non-research language?
The first thing to know is that aldosterone is in charge of the retinal fluid homeostasis. The theory is when that is out of whack, it leads to increased choroidal vascular permeability which can lead to CSR.
This makes scientists wonder, is there an aldosterone receptor (aka mineralcorticoid receptor) we can target to keep the fluid permeability in check?
Yes. Conveniently, these receptors were found to exist in the retina of rats.
So to connect the dots…
Aldosterone is responsible for retinal fluid homeostasis. Too much aldosterone means a leaky choroid which can lead to CSR. By using an aldosterone antagonist drug (i.e. spironolactone), we can reverse that problem.
What are some side effects of oral spironolactone?
There are a few. Fatigue, dizziness, gastric pain, gynecomastia, blood pressure fluctuation, and hyperkalemia although none were reported in this study.
How did the patients do in the study?
At 2 months, almost 56% of the spironolactone group had complete resolution of CSR compared to 8% of the observe group.
The authors state their results may help achieve faster recovery of CSR when the patients refuse other treatment options. (via)