What are the causes and treatment options for Central Serous Choroid Retinopathy (CSCR)?

Central Serous Chorioretinopathy (CSCR): Causes and Treatment

Causes and Pathogenesis

CSCR results from choroidal dysfunction and abnormalities that lead to fluid leakage through defects in the retinal pigment epithelium (RPE), causing subretinal fluid (SRF) accumulation beneath the neurosensory retina. 1

• The primary pathology involves a thickened and dysfunctional choroid with venous congestion of choroidal outflow, which secondarily affects the RPE barrier function 2, 3
• Risk factors include psychosocial stress, hypercortisolism, and glucocorticoid medication use 3
• The condition predominantly affects middle-aged individuals, with higher prevalence in men 3
• Patients typically present with blurred vision, metamorphopsia (distorted vision), and a central dark spot, usually affecting one eye 3

Treatment Approach: Acute vs. Chronic CSCR

Acute CSCR (symptoms < 4 months)

For first-time acute CSCR, observation for 3-4 months is the standard approach, as spontaneous resolution occurs in the majority of patients. 4

However, immediate treatment with ICGA- and FA-guided half-dose photodynamic therapy (PDT) should be performed without observation in the following situations: 4

• Patients requiring rapid visual recovery for professional reasons
• Recurrent episodes of CSCR
• Bilateral active disease
• Previous episodes of SRF 1

Half-dose PDT achieves faster SRF resolution, more rapid recovery of retinal sensitivity, and significantly lower recurrence rates (25%) compared to spontaneous resolution (51.2% recurrence). 4, 1

Chronic CSCR (persistent SRF > 4-6 months)

ICGA- and FA-guided half-dose (3 mg/m²) or half-fluence PDT with verteporfin is the first-line treatment for chronic CSCR and should be considered the preferred treatment. 1, 5, 4

The evidence supporting this recommendation:

• The PLACE trial demonstrated that half-dose PDT achieved complete SRF resolution in 67% of patients at 7-8 months versus only 29% with high-density subthreshold micropulse laser (HSML) 1
• The SPECTRA trial showed half-dose PDT was superior to eplerenone (mineralocorticoid receptor antagonist) for achieving complete SRF resolution and functional improvement 1
• Large RCTs demonstrate 21-100% complete SRF resolution rates with PDT 1, 4
• PDT targets the underlying choroidal abnormalities, not just the RPE leak 1
• PDT has an excellent safety profile with no permanent choriocapillaris damage, even when including the fovea in the treatment spot 1

The treatment goal is to prevent irreversible photoreceptor damage and vision loss, as persistent SRF causes progressive, partly irreversible photoreceptor atrophy and reduced quality of life. 1

PDT Technical Specifications

Half-dose verteporfin (3 mg/m²) is preferred over half-fluence or half-time protocols because: 1, 4

• Large RCTs demonstrate high efficacy in chronic CSCR
• Minimizes local and systemic side effects
• A single vial can treat two patients, reducing costs and increasing availability during verteporfin shortages 1

Use ICGA- and FA-guided targeting of hyperfluorescent areas corresponding to focal leakage and SRF on OCT. 4

Post-treatment precautions: 5

• Avoid direct sunlight and UV radiation for 48-72 hours
• Wear protective clothing
• Follow-up imaging at 4-6 weeks to assess treatment response 5

Alternative Treatment Options

If PDT is unavailable or SRF persists after initial PDT:

Argon laser photocoagulation can be considered only when: 1, 4, 2

• Focal leakage on FA is located at a safe distance from the fovea (not near central macula)
• May achieve rapid short-term SRF resolution 1

Critical limitations: Does not target underlying choroidal dysfunction and carries significant risks including symptomatic paracentral scotoma, macular neovascularization (MNV), and chorioretinal adhesions with secondary cystoid changes 1, 4

Mineralocorticoid receptor antagonists (eplerenone, spironolactone) may be considered: 1, 4

• When PDT is unavailable
• As adjunctive therapy
• Evidence is limited and inferior to PDT based on the SPECTRA trial 1

High-density subthreshold micropulse laser (HSML) shows inferior results compared to half-dose PDT in both focal and diffuse chronic CSCR phenotypes, with only 14-29% achieving complete SRF resolution versus 51-67% with PDT 1, 4

Management of Persistent or Recurrent Disease

If SRF persists after initial PDT: 4

• Consider re-treatment with PDT guided by FA/ICGA
• Trial of mineralocorticoid receptor antagonist
• High-density micropulse laser (though less effective)
• Continued observation in select cases

Important Clinical Caveats

• Patients with pre-existing foveal atrophy may achieve SRF resolution but have limited visual function improvement 5
• Chronic CSCR with concurrent macular neovascularization should be treated with half-dose PDT and/or intravitreal anti-VEGF injections 1
• Waiting 4 months before intervention in acute CSCR does not appear to affect longer-term outcomes in most cases 1
• OCT can detect atrophic photoreceptor outer segments from chronic foveal SRF even without visible RPE abnormalities, indicating the need for earlier intervention in some cases 1