Abstract
Purpose: :
To evaluate the choroidal thickness in eyes with retinitis pigmentosa (RP) and its association with photoreceptor layer.
Methods: :
Fifty eyes of 50 patients (mean age, 48.6 years) with RP but no other retinal or optic nerve diseases were examined with spectral-domain optical coherence tomography. The thickness of choroid and photoreceptor layer at the fovea, 1.5mm and 3.0mm superior, inferior, nasal, and temporal from the fovea was measured with the scale supplied with the software.
Results: :
The means ± SD of choroidal thickness were 228 ± 74µm at the fovea, 220 ± 64 µm at 3.0mm superiorly, 174 ± 61µm at 3.0mm inferiorly, 104 ± 51µm at 3.0mm nasally, and 197 ± 66 µm at 3.0mm temporally. Subfoveal choroidal thickness was significantly greater than that of nasal, inferior, and temporal regions; however, there was no significant difference compared with that of superior region. Subfoveal choroidal thickness did not correlate with foveal photoreceptor layer thickness, but was significantly associated with the average of photoreceptor layer thickness in 1.5mm superiorly, inferiorly, nasally, and temporally (r=0.37, P < 0.01).
Conclusions: :
The foveal choroid in eyes with RP was obviously thinner than that of previously reported normal eyes: 354µm (Ikuno et al. IOVS 2009). Especially, those with thin photoreceptor layer had thin choroid. The result might indicate that the choroidal thinning in eyes with RP is due to the degeneration of photoreceptors and subsequent volume reduction of the choroidal circulation. Altenatively, the degeneration of retinal pigment epithelium might induce the atrophy of choriocapillary bed and make the choroid thinner.
Keywords: choroid • retinal pigment epithelium • photoreceptors