Central serous chorioretinopathy (CSR)

Central serous chorioretinopathy (CSCR) is an eye disease that causes visual impairment, often temporary, and usually in one eye, but can be bilateral. When the disorder is active, it is characterised by fluid leakage under the retina that has a propensity to accumulate under the central macula. This causes blurred or distorted vision (metamorphopsia). When the retina is detached; a blurred or grey spot in the central visual field is common. The vision may improve over 3 to 6 months in the majority of cases; however, in a proportion of people vision can deteriorate over time and/or the fluid accumulation does not resolve spontaneously and becomes chronic.

What is central serous chorioretinopathy?

Central serous chorioretinopathy (CSCR) is a build-up of fluid behind the retina inside the eye, including under the central retina (macula). The retina is the light-sensitive layer of the eye, with the macula being responsible for detailed vision. The build-up of fluid can cause the retina to detach, and this can cause visual disturbance.

The disease has no confirmed cause, but there are several identified risk factors for developing CSCR. The factors that increase risk of CSCR (or recurrence) include: (i) Men are at far greater risk than women, (ii) Type A personality – including being short tempered, (iii) Steroid use by any route e.g. oral, inhaled, ear and eye drops, creams, (iv) Poorly controlled blood pressure, (v) Smoking, and (vi) Experiencing high levels of stress.

It is believed that early treatment is often key to making the best recovery when the condition has not resolved spontaneously.


The main symptom is blurred vision. The patient may also notice that the area around their central vision starts to darken or becomes blurry. It is very common to have the visual difficulties in one eye only, but it’s also possible to develop the condition in each eye at different times.

Other symptoms may include:

Talk with Prof. Michel if you have any of these symptoms right away here


Sometimes no treatment is required. In these cases, Prof. Michel will monitor to ensure the fluid is resolving and no intervention will be required, as it may take several months for the fluid to fully disappear. But in some other situations, the fluid will not drain away without intervention, and fortunately, there are some potential treatment options available, including:

Photodynamic therapy

Photodynamic therapy (PDT) with verteporfin (VisudyneTM) is primarily used for the treatment of chronic central serous chorioretinopathy (CSCR) and idiopathic polypoidal choroidal vasculopathy (IPCV). Private Health Insurance companies may reimburse patients for PDT due to IPCV, which is a subform of wet Age-Related Macular Degeneration and increasingly for CSCR.

How does photodynamic therapy work?

The principle of the treatment is that a photosensitive dye (VisudyneTM) is infused into the bloodstream 15 minutes before treatment with a 699nm diode laser. The dye concentrates in abnormally leaky and congested layers (chronic CSCR) or abnormally dilated blood vessels (IPCV) beneath the retina. The wavelength of the laser light coincides with the wavelength of Visudyne’s sensitivity, such that the laser light is concentrated and preferentially absorbed into the leaky layer or abnormally dilated vessels under the retina. 

Studies have shown that the absorbed laser energy works by causing ischaemia, i.e. a reduced blood supply to these structures. This, in turn, causes them to thin down and therefore leak less (chronic CSCR) or occlude and thrombose (IPCV), thus preventing leakage or haemorrhage from occurring. 

If leakage (CSCR) or blockage (IPCV) is only partial, then retreatment may be necessary 10 to 12 weeks later. 

Thus, photodynamic therapy aims to selectively treat the underlying disorder without compromising the function of the normal macula.

How effective is the treatment?

Central serous chorioretinopathy

There is a lot of literature regarding central serous chorioretinopathy and treatment by photodynamic therapy. Of all the possible treatments for this condition, i.e. focal laser treatment, eplerenone or other drug therapy, or other types of laser treatment, it is thought to be the most effective. However, it is fair to point out that there is a lack of large well-conducted prospective studies with patients randomised to treatment versus no treatment to exactly define how effective it is. 

In addition, central serous chorioretinopathy can occur in different forms, i.e. an acute form that typically lasts for six months and may resolve spontaneously and a chronic form which may occur in multiple sites in both eyes and is less likely to resolve spontaneously. Studies that have looked at the treatment of photodynamic therapy in central serous chorioretinopathy have often included patients from both groups, which can make exact interpretation of the data difficult. 

Overall however, there is moderately good evidence that photodynamic therapy compared to no treatment in patients with active central serous chorioretinopathy with subretinal fluid at the macula who are symptomatic will likely gain an average of 1 to 2 lines of vision after three years. In chronic cases, relatively modest (e.g. one line ) improvements in vision are usual. 

Most studies analyse rates of subretinal fluid resolution. Resolution typically occurs in over 80% of ‘acute’ cases at 12 months. Recurrence, not necessarily from the same site can occur in 20% of acute treated cases and 53% of acute untreated patients. Clinical trial information in chronic cases is less clear, but we would expect subretinal fluid to clear in the majority of chronic cases, i.e. approximately 80%. The benefit may only last 1 to 2 years in some cases, but has lasted for much longer in others.

Idiopathic Polypoidal Vasculopathy

Half or full-fluence photodynamic therapy in some cases of idiopathic polypoidal vasculopathy is a necessary adjunct to anti-VEGF therapy. There is evidence that the visual outcome and closure of the polyps to prevent subretinal haemorrhage is superior when photodynamic therapy is combined with anti-VEGF therapy. However, this is not necessary in all cases, and Prof. Michaelides will discuss this with you when he sees you.

What does the treatment involve?

Photodynamic therapy is done on an out-patient basis and takes approximately 60 minutes if all preceding tests, i.e. fluorescein and indocyanine green angiography have already been performed, but 2 to 3 hours if not.  

On arrival at The London Medical, the nurse will meet you and take some preliminary measurements, i.e. height and weight. Your visual acuity will be tested; pupils dilated, a clinical examination performed by Prof. Michaelides, an intravenous cannula will be inserted by one of the nursing team, and any other tests that are necessary, i.e. OCT, fluorescein and/or indocyanine green angiography will be performed. 

Prof. Michaelides will check the clinical appearances of your eyes with the scans performed, make the necessary preparations, and ask you to sign a consent form. After this, the treatment will be performed in a dedicated laser area. An intravenous infusion of Visudyne will be started and runs over a 10-minute period. Three minutes after this, a contact lens will be placed on the eye and the laser treatment performed 2 minutes later. This laser treatment lasts for 83 seconds and is completely painless. 

Treatment is performed at The London Medical, 49 Marylebone High Street, London W1.

Side effects & risks

VisudyneTM is a photosensitive drug that will be in the bloodstream for 48 hours after infusion. Since it will remain in skin blood vessels during this time, sun exposure for 48 hours after treatment could lead to significant burns of the skin. For this reason, exposure to direct sunlight and bright indoor halogen spotlights must be avoided for 48 hours after treatment. 

Most patients stay indoors during this time. It is advisable to half pull curtains to shade out direct sunlight, but it is not necessary to sit in the dark. Watching television and working indoors on a laptop under artificial light is entirely reasonable. Routine dentist and doctor appointments should be postponed for the two days after treatment. If it is absolutely necessary to go outdoors, then dark glasses, hat and clothes to cover all exposed skin should be worn. 

Alcohol is best avoided for 48 hours after treatment. Low back pain has occasionally been reported with the infusion but usually ceases when the infusion ends. 

Some patients notice that their vision is slightly worse in the week following treatment. Usually, however, it has returned to pre-treatment levels two weeks after treatment. If you feel your vision remains impaired two weeks after the treatment, then do not hesitate to contact Prof. Michaelides.

Book a Consultation

Your message has been sent. We will get back to you.