Foveal outer retinal bands remodeling following reabsorption of neurosensory detachment in chronic central serous chorioretinopathy (CCSC) treated with photodynamic therapy (PDT)

Abstract

Purpose: To report the morphological and functional recovery of the foveal outer retina bands following reabsorption of subretinal fluid in CCSC treated with PDT.

Methods: The study group comprised 11 eyes (11 patients - 9 Male, 2 Female), with CCSC and foveal neurosensory detachment of ≥6 months duration with no other previous ocular pathology. ICG-guided full fluence (50 mJ/cm²) 689nm laser was applied over 83 seconds after I.V. infusion of half-dose verteporfin (3mg/m²) at baseline, and full dose for any repeat PDT. All patients had follow ups at 6 weeks, 3 months and 1 year post treatment. At each visit visual acuity was measured using an Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Spectral Domain Optical Coherence Tomography (OCT) was carried out to measure central retinal thickness (CRT) and presence / absence of SRF. The External Limiting Membrane (ELM), Ellipsoid Zone (EZ), Outer Segments (OS), Interdigitation Zone (IZ) and Retinal Pigment Epithelium (RPE) were assessed for anatomical continuity and graded each as continuous, disrupted or undetectable.

Results: SRF resolved in all cases of CCSC after a single session of PDT a part from one eye requiring repeat PDT at 12 weeks. The ETDRS score was 63 (20/63+3) at baseline (SD: 11.65), 70 (20/40) at 6 weeks (SD: 9.51), 71.5 (20/40⁺¹) at 3 months (SD: 9.65) and 74.5 (20/32^-1) at 1 year (SD: 8.00). Central macular thickness (CMT) measured by OCT changed from a mean of 281.5µ (range: 250-448µ, SD: 8) at baseline, to 225.5µ (range: 298-207µ, SD: 26) at 6 weeks, 231µ (range: 297-205, SD: 28) at 3 months and 234µ (range: 208-304µ, SD: 26) at 1 year. The ELM was continuous in all eyes from baseline to year one. The EZ, OS and IZ became progressively more recognizable with time, from being disrupted or undetectable at baseline in 100% of eyes to appearing continuous at 1 year in 81.8%, 40% and 9.1% of eyes respectively. There was no recurrence of subfoveal neurosensory detachment.

Conclusions: PDT seems to aid fast resolution of SRF in CCSC. Anatomical and visual acuity recovery may be slower, with the OS and the IZ appearing more susceptible to long term structural abnormalities. A larger sample may provide better understanding of functional and anatomical recovery interaction following regression of subretinal fluid in CCSC.