Retinal Case of Interest: CSR
Central serous retinopathy (CSR), also known as central serous chorioretinopathy (CSC), is an eye condition where fluid accumulates underneath the retina causing distortion and visual loss.
Patients are typically 20-50 years old and often complain of a sudden, painless loss of vision. Older patients are more likely to have systemic hypertension or a history of corticosteroid use.
This condition occurs 8-10 times more commonly in men than in women and is more common in Caucasians.
It is felt that this may be a stress-related condition as it is more common in patients with "Type A" personalities.
Patients may be asymptomatic unless the central part of the retina (macula) is affected. In these cases, they note decreased or blurred vision, distortion, micropsia (small image size), and abnormal colour vision. Visual acuity can range from 6/6 to 6/60.
Fundus examination shows a localised retinal elevation (serous retinal detachment) but no blood. There may also be a detachment of the outermost layer of the retina called retinal pigment epithelium (RPE). Occasionally, there may be some small yellow spots in the area of detachment. There may be other areas with changes in pigmentation which are believed to correspond to previous CSR episodes.
One of the functions of the RPE is to keep fluid from leaking out of the choroidal vascular area into the area under the retinal surface. CSR develops when fluid from the choroidal vascular layer passes through the RPE to accumulate underneath the retina forming a blister.
Previous hypotheses for the pathophysiology have included abnormal ion transport across the RPE and focal choroidal vasculopathy. The advent of indocyanine green (ICG) angiography has highlighted the importance of the choroidal circulation to the pathogenesis of CSR.
ICG angiography has demonstrated both multifocal choroidal hyperpermeability and hypofluorescent areas suggestive of focal choroidal vascular compromise. Some investigators believe that initial choroidal vascular compromise subsequently leads to secondary dysfunction of the overlying RPE.
Studies using multifocal electroretinography have demonstrated bilateral diffuse retinal dysfunction even when CSR was active only in one eye. These studies support the belief of diffuse systemic effect on the choroidal vasculature.
Type A personalities, systemic hypertension, and obstructive sleep apnoea may be associated with CSR. The pathogenesis here is thought to be elevated circulating cortisol and epinephrine, which affect the autoregulation of the choroidal circulation.
Corticosteroids have a direct influence on the expression of adrenergic recepor genes and, thus, contribute to the overall effect of catecholamines on the pathogenesis of CSR. Consequently, multiple studies have conclusively implicated the effect of corticosteroids in the development of CSR.
Systemic associations of CSR include organ transplantation, exogenous steroid use (odds ratio 37:1), endogenous hypercortisolism (Cushing syndrome), systemic hypertension, sleep apnoea, systemic lupus erythematosus, pregnancy (odds ratio 7:1), gastroesophageal reflux disease, and use of psychopharmacologic medications.
One study has showed an association between Helicobacter pylori infection and CSR. The prevalence of H pylori infection was 78% in patients with CSR compared with a prevalence of 43.5% in the control group. It was proposed that H pylori infection may represent a risk factor in CSR, though no further studies have substantiated this claim.
Serous retinal detachments typically resolve spontaneously in most patients, 40-50% recovering in 6 weeks, with most patients (80-90%) returning to 6/9 or better vision within 6 months. Even with return of good central visual acuity, many of these patients still notice abnormal colour vision, loss of contrast sensitivity, distortion, or, rarely, night blindness.
Patients with classic central serous chorioretinopathy (CSR) (characterised by focal leaks) have a 40-50% risk of recurrence in the same eye. Risk of choroidal neovascularisation from previous CSR is considered small (<5%) but has an increasing frequency in older patients diagnosed with CSR.
A subset of patients (5-10%) may fail to recover 6/12 or better visual acuity. These patients often have recurrent or chronic serous retinal detachments, resulting in progressive RPE atrophy and permanent visual loss to 6/60 or worse. The final clinical picture represents diffuse retinal pigment epitheliopathy.
This is a condition that may recur. As many as 40-50% of patients will have one or more recurrences, which can occur many years later. About 10% of patients will have 3 or more episodes.
For most patients, observation and reassurance is all that is necessary.
If possible, steps to reduce external stressors should be taken.
In addition, any ongoing corticosteroids should be reconsidered and if possible, stopped as they can worsen the disease.
Historically, ruby laser photocoagulation at the site of leakage was found to accelerate resolution but did not result in a better visual acuity, and did not reduce the rate of recurrence.
In patients with CSR who meet the following characteristics:
- A non-resolving serous detachment for at least two months
- A site of leakage away from the foveal centre
- An occupational need for expedited visual recovery
laser treatment may be considered to shut down the leaking vessels.
Additionally, intravitreal injection of Avastin (Acetazolamide) to treat CSR has been shown to shorten the time for subjective and objective clinical resolution, but had no effect on either final visual acuity or recurrence rate of the disease.
An interesting case study of a typical patient can be seen below.
Mr X presented to Sydney Retina Clinic with a decrease in left eye central vision over a three week period. He has a history of left eye CSR, with the last episode occurring in 2006. At his last visit to Sydney Retina Clinic (in 2006) his visual acuity in the left eye was 6/6.
His visual acuity was measured to be 6/15 in the left eye.
Mr X is a 39 year old male with no current medical problems or significant health history. He was not taking any regular medication. Mr X is a smoker and admits to being easily stressed.
Mr X underwent OCT and ICG (fluoresceine angiography not able to be performed due to allergy). ICG showed a leak and confirmed the diagnosis of central serous choroidopathy. OCT showed sub retinal fluid.
Above: ICG showing area of leakage in the macula
Above:OCT showing left eye sub retinal fluid.
A conservative approach was taken and Mr X was instructed to return in one month for review. In that month, Mr X ceased smoking and tried to reduce stress levels.
On one month review, Mr X stated there had been a noticeable improvement in his left eye vision. His visual acuity was measured at 6/12. On OCT, a dramatic improvement in CSR is seen. Mr X is advised to cease smoking permanently. He will be reviewed again in two months
Above: OCT at one month review. Noticeable improvement in CSR.