Abstract
Purpose: :
To evaluate retinal thickness and the thickness of the outer photoreceptor layer in patients with resolved central serous chorioretinopathy (CSCR).
Methods: :
Five eyes of 4 patients were examined with OCT after the foveal serous detachment was fully resolved. All eyes were examined with an OCT based on the spectrometer detection system (HD-OCT, Cirrus, Carl Zeiss Meditec). The retinal thickness was measured in the foveal subfield, (1000 µm diameter) using the standard retinal map. The thickness is measured from the inner limiting membrane (ILM) to the central retinal pigment epithelium (RPE) by the in-built algoritm. With the same definition, the foveal thickness of the center was measured manually. The outer photoreceptor layer thickness from the IS/OS junction to the posterior retinal pigment epithelium (RPE-OScomplex) was also measured manually. Results were compared to 10 healthy eyes.
Results: :
In eyes with resolved CSCR, the thickness of the foveal subfield of was decreased by 59 µm corresponding to 22% of healthy values ( p<0.001), smaller changes was seen in the more peripheral macula. In the foveal center, the retinal thickness was reduced by 60 µm or 28% in CSCR ( p<0.045). Also, the RPE-OScomplex was reduced significantly by 14 µm or 20% (p<0.01). The changes in the fovea was also visible qualitatively, as an increased backscatter from the outer nuclear layer in the fovea, a layer which appears dark in healthy subjects.
Conclusions: :
The foveal subfield thickness was significantly reduced in resolved CSCR. Also, a marked and significant decrease was found of the central RPE-OScomplex and a borderline significant decrease of the central foveal retinal thickness. Despite the small number of eyes included, the results underlines the usability of measurements of all possible layers of the outer retina. In particular, the highly reflecting IS/OS junction and the outermost RPE lines may be valuable as robust and clinically relevant reference lines. Evaluated qualitatively, the reflectance of the photoreceptor nuclear layer in the fovea is increased in CSCR, propably due to formation of fibrous tissue and/or loss of normal anatomy. The decrease in the thickness of the RPE-OScomplex may reflect corresponding loss of outer segments.
Keywords: imaging/image analysis: clinical • clinical research methodology • macula/fovea