INTRODUCTION

Central serous retinopathy (CSR) is believed to be an idiopathic disorder typically found in the macula, characterised by a neurosensory detachment from the retinal pigment epithelium (RPE) and a localised pigment epithelial detachment (PED). Patients with CSR usually present with complaints of sudden onset distortion or blurring of central vision.

EPIDEMIOLOGY

Generally, patients with CSR are younger, with most cases occurring between the ages of 25 and 50 with the mean age at diagnosis being 41 years. Men are afflicted more frequently than women, with an incidence ratio of about 6:1. Pregnancy is a recognised risk factor for CSR, with an identified odds ratio of 7.1. There are few, if any, racial predilections with patients of European and Asian descent appear to be affected equally. “Type A” personality psychological trait is the most well-known association with CSR. CSR is often found in patients who have a history of using corticosteroids (topical, injectable, or oral), sympathomimetic agents, or medications for erectile dysfunction. Also, it is known that there are several contributory elements such as obstructive sleep apnea, antibiotics, uncontrolled hypertension, alcohol, and allergic respiratory disease. Typically, CSR affects one eye, although bilateral cases have been reported, and the likelihood of subsequent involvement of the fellow eye may be as high as 40%.

SIGNS AND SYMPTOMS

Symptoms of CSR can include a loss of central vision, a central scotoma, micropsia, metamorphopsia, reduced colour discrimination, and diminished contrast sensitivity. Visual acuity may only be reduced moderately, and the refraction tends to reveal a hyperopic shift in most cases. 

PATHOPHYSIOLOGY

The pathogenesis of CSR appears to have a multifactorial aetiology, with various systemic associations and complex pathogenesis. Risk factors associated with CSR include higher stress levels, increased caffeine consumption, testosterone supplements, pregnancy, obstructive sleep apnea, Heliobacter pylori ulcers resulting in increased vascular permeability of the choroid causing a localised accumulation of subretinal fluid or a neurosensory detachment. Serum levels of glucocorticoids and catecholamines are elevated and disrupt the integrity of Bruch’s membrane. The primary dysfunction appears to be localised ischaemia and/or inflammation at the level of the choriocapillaris, which leads to hyperpermeability; this, in turn, results in decompensation of the retinal pigment epithelium, causing a focal detachment of the overlying neurosensory retina.

MANAGEMENT OF CENTRAL SEROUS RETINOPATHY

The majority of cases of CSR are self-limiting over a period of three to 12 months. The prognosis for visual recovery is excellent, with most regaining their pre-CSR visual acuity. Upon diagnosing the condition, any corticosteroid therapy should be immediately discontinued, if possible. A consultation with the patient’s primary care physician may be indicated in cases involving steroidal anti-inflammatory agents for systemic conditions and steroidal inhalers for asthma.

Clinical evaluation of the patient with CSR reveals no external signs of ocular disease or inflammation. Refraction often reveals mild hyperopic refractive shift (+1.25 D or less) in the affected eye. Dilated funduscopic examination shows a distinct, round or oval serous elevation of the macula with a loss of the foveal light reflex. OCT classically shows a bullous neurosensory retinal detachment from the underlying choroid, separated by an optically empty zone. An underlying area of RPE detachment may be seen concurrently in about 10% of patients. Associated findings can include cystoid macular degeneration, retinal atrophy, and RPE tears, especially in chronic cases. There exists the possibility of choroidal neovascularisation (CNV) as well.

Although CSR is thought to be self-limiting in most cases, treatment should be considered in some cases. These include monocular patients, who need a more rapid recovery in visual acuity to perform work or vocational tasks, those who have had a poor visual outcome from chronic CSR in the fellow eye or persistent subretinal fluid beyond three to four months. Optometrists can manage CSR with acetazolamide 250mg qhs. At follow-up three weeks later, visual recovery to a level of 20/20- is expected and OCT imaging will confirm near complete resolution of the neurosensory detachment. 

Studies show a relationship between mineralocorticoid (MR) receptors and choroidal vascular dilation, which collaborate to develop CSR. Thus, the use of an MR antagonist, such as spironolactone 50mg QD, can be an effective treatment option for chronic CSR. Other treatment options for CSR include the diuretic eplerenone; the antibiotic rifampin; and the hormone supplement melatonin. Recalcitrant cases warrant referral to a retinal specialist for fluorescein angiography and aggressive treatment. Fluorescein angiography will typically demonstrate a focal point of fluorescein leakage under the serous detachment that gradually expands to fill the entire lesion; it is sometimes referred to as a “smokestack” or “ink blot” hyperfluorescent pattern and a well-defined serous PED. Focal laser photocoagulation can also help with subretinal fluid absorption. Research also shows low-fluence photodynamic therapy (PDT) with the light-activated drug Visudyne (verteporfin, Bausch & Lomb) can be effective for CSR treatment. Other experimental treatments for CSR that have shown modest success include, anti-VEGF treatment and transpupillary thermotherapy.

CLINICAL PEARLS

• Young, anxious, otherwise healthy patients who presents with unilateral metamorphopsia of recent onset represent the classic presentation for CSR.
• Individuals, who are described as exhibiting the characteristics of time urgency, aggressiveness, hostility and competitiveness, seem to be particularly predisposed to developing CSR.
• It is important to consider this condition in pregnant women who present with sudden onset of visual complaints as well as patients taking Viagra with similar complaints.
• When asking patients about any possible exposure to steroids, be sure to question them on the use of any products that may contain steroids, such as creams, inhalants, nasal sprays and joint injections.
• Research shows sleep apnea is present in up to two-thirds of patients with CSR and should be considered an associated risk factor, especially in patients who suffer from recurrent episodes of CSR or have chronic symptoms.
• Patients presenting with CSR for the first time should be reassured, counselled as to the natural course of the condition, and monitored every three to four weeks for three to six months as resolution occurs.
• A referral to a retinal specialist is indicated to rule out the need for fluorescein angiography. Fluorescein angiography is used to identify the presence of a “hot spot”, which shows up as hyperfluorescence at the site of RPE detachment. If the patient fails to resolve after six months, the retinal specialist may consider more aggressive therapy such as laser photocoagulation, PDT, or anti-VEGF.
• Acute CSR may be present in patients on chronic Kenalog (corticosteroid) injections in the scalp for the treatment of alopecia, an autoimmune disease characterised by hair loss.
• While the acute phase of CSR is usually self-limiting, the condition may be recurrent in as many as 50% of affected individuals. These patients often demonstrate cystic yellow lesions in the macula known as lemon-drop nodules. Lemon-drop nodules are indicative of mild RPE detachment. They may also stimulate RPE hyperplasia.
• Given spironolactone’s status as a potassium-sparing diuretic, clinicians should consider evaluating the patient’s potassium level prior to its implementation.

CONCLUSION

CSR patients must be educated on lifestyle modifications involving the known risk factors such as steroid use, increased caffeine consumption, higher stress levels, testosterone supplements, pregnancy, Helicobacter pylori ulcers, Viagra use and obstructive sleep apnea.

REFERENCES

Kanski JJ. Clinical Ophthalmology. A Systematic Approach. 5^th Ed. London: Butterworth Heinemann. 2003,421-3.

Vaughan D, Asbury T. General Ophthalmology. 10^th Ed. Los Angeles: Lange Medical Publishers,221-222.

Sowka JW, Gurwood AS, Kabat AG. Central serous chorioretinopathy. Review of Optometry.14^th Ed. June 2012.