Central Serous Chorioretinopathy - Causes, Symptoms, Diagnosis, Differential Diagnosis, and Management

Introduction

Central serous chorioretinopathy (CSCR) is a localized detachment of the retina also macula. It causes distortion or loss of central vision. It mainly affects the males, especially in the twenty to sixty age group. Above sixty years, the disease shows bilateral involvement. Females involved belong to an older age group. American Africans, Caucasians, and Asians are at a higher risk of contracting CSCR.

What Is Retina?

The retina is present at the back of the eye and helps sense the external light and transfer the formed images to the brain. Retina has a rich meshwork of blood vessels and nerves.

What Is the Main Causative Factor of CSCR?

CSCR is of multifactorial origin. Therefore, no single pinpoint cause is responsible for the development of the disease. However, there is a strong association between the abnormal retinal pigment epithelium (RPE) and CSCR. Other causative factors include:

• Steroids, both exogenous and endogenous, are responsible for altering the permeability of the choroidal capillaries.

• Stress and people with a low threshold for distress show overexpression of stress hormones like steroids and catecholamines.

• Helicobacter pylori infection causes increased oxidative stress in the retinal tissues.

• The use of Methylenedioxymethamphetamine (MDMA) modulates the choroidal blood flow.

• Obstructive sleep apnea.

• Increase in sympathetic activity.

• Genetic factors.

What Are the Additional Contributing Risk Factors Associated With CSCR?

Numerous factors are linked to the initiation and progression of the disease. These include:

• Pregnancy.

• Antibiotic usage.

• Alcohol abuse.

• Untreated hypertension.

• Disturbances in sleep pattern.

• Psychiatric disorders like depression.

• End-stage renal disease.

• Systemic lupus erythematosus.

• Organ transplantation.

What Is the Mechanism Behind the Formation of CSCR?

It is challenging to elucidate the exact mechanism behind the instigation of CSCR. However, the increase in vessel permeability supplying the middle layer of the eyewall (choroid) and choking (congestion) of the veins leads to fluid leakage from the capillaries. The leak reduced the blood flow (ischemia) and increased hydrostatic pressure in the choroidal network resulting in RPE damage and focal lesions. The retinal blood and external blood barrier break down, thus causing an accumulation of fluid in the subretinal space.

What Are the Different Forms of CSCR?

CSCR is of two forms:

• The acute form of the CSCR lesions is characterized by localized damage to the RPE, and the lesions regress spontaneously. In addition, there is an increase in choroidal thickness due to new blood vessels (choroidal neovascularization). However, other outer layers of the choroid are intact.

• Chronic forms of CSCR show diffuse RPE lesions and result in deterioration of the visual acuity. In addition, it affects the inner layers of the choroid with thinning of the inner layers. It is also associated with choroid neovascularization.

What Are the Clinical Features of CSCR?

The main symptom expressed by patients suffering from CSCR is loss of visual acuity.

• Clinical examination with an ophthalmoscope reveals detachment of the macula. In addition, yellow subretinal deposits are seen in the region of nerve detachment.

• The presence of gray, fibrous subretinal fluid leakage is seen.

• In recent cases, multiple RPE lesions are seen in the case of macular edema with shallow detachments or elevation of the retina.

• Other frequently encountered signs and symptoms include:

• Reduction in the perceived size of the object (micropsia).

• Abnormal color perception (dyschromatopsia).

• Diminished contrast sensitivity by the eyes.

How Is CSCR Diagnosed?

Diagnosis of CSCR is mainly made by clinical examination. Imaging and other diagnostic procedures aid in treatment planning and the diagnosis by ruling out other diseases with similar patterns.

• Amsler grid is used to detect concealed macular edema lesions and localize the affected visual field.

• Fluorescein angiography (FA) is performed to rule out any subretinal new blood vessel formation (neovascularization). It shows the classic ink-dot, smoke pattern appearance of the lesion.

• Optical coherence tomography (OCT) helps assess the fibrous subretinal fluid and the patient's progress after treatment. It also majorly helps in detecting choroidal neovascularization.

• Fundus autofluorescence is functional imaging performed to study the RPE, choriocapillaris, and choroid.

• Indocyanine Green angiography helps detect the leakage from the blood vessels that enter the subretinal space. It also helps in investigating the abnormal functioning of choriocapillaris.

What Are the Conditions That Mimic CSCR?

Differential diagnosis of CSCR encompasses all the conditions causing macular detachment. The states with a neurosensory break in the macula include:

• Macular derangement.

• Choroidal tumor.

• Hypertensive choroidopathy.

• Retinal vein occlusion.

How Is CSCR Managed?

CSCR being a limiting condition hardly requires any treatment. However, treatment is advised in case of recurrent or chronic lesions. Therefore, management of CSCR involves both medical and surgical management.

Medical Management of CSCR Comprises Of:

• Anti-steroidal therapy with Spironolactone and Eplerenone is linked to decreased fluid accumulation. However, the anti-steroids are given with caution as they increase potassium in the body resulting in congestive heart failure and chronic kidney disease. In addition, melatonin, an endogenous neuromodulator, is known to have an inhibitory effect on steroids.

• Treatment of the helicobacter pylori infection also is linked to faster resolution of the subretinal fluid.

• Intravitreal and anti-vascular endothelial growth factor (anti-VEGF) therapy is beneficial in patients with coexisting choroidal pathology.

Surgical Management of CSCR:

It is recommended in chronic, long persistent, and recurrent cases.

• Laser photocoagulation is considered in patients with RPE not involving the fovea present in the retina. It can cause other complications like choroidal neovascularization and scotomas (blind spots in vision).

• Photodynamic therapy with Verteporfin and warm lasers help in damaging the newly formed vessels and intercepts the abnormal blood flow. It is given in low doses to avoid secondary complications like the stimulation of VEGF. PDT is more effective than the intravitreal injection of anti-VEGF.

• Subthreshold micropulse laser overcomes the shortcomings of the conventional laser by emitting a pulse flow of light, hence preventing overheating of the adjacent tissues. In addition, it mainly inhibits the formation of new blood vessels (anti-angiogenic effect).

What Are the Complications of CSCR?

Recurrent and persistent infection of the lesion due to disruption of the retinal architecture leads to some lasting eye complications like:

• Decrease in night vision.

• Reduction of color discrimination.

• Bullous retinal detachment.

• Scarring of the RPE.

• Fibrosis of the subretinal space.

What Is the Prognosis of CSCR?

CSCR is a self-limiting condition. The acute form of the disease resolves spontaneously. However, management is required in chronic states to minimize further complications. The overall prognosis of the disease is excellent. However, CSCR has a high recurrence rate.

Conclusion

CSCR remains a mysterious disease with a multifactorial cause. The initiation and progression of the disease are still unclear. Blurred vision is the chief problem encountered in these patients. However, most cases get resolved by themselves with good visual acuity.