Abstract
Purpose: :
To evaluate in patients affected by retinitis pigmentosa (RP) the choroidal thickness and the relation with visual acuity.
Methods: :
Twenty-eight eyes of 14 patients (mean age, 56.8 years, 8 male, 6 female) with RP were examined with spectral-domain optical coherence tomography (Spectralis OCT, Heidelberg Engineering). Patients with any additional ocular disease, vitreo-retinal traction, macular edema ametropias of more than 6 diopters (D), were excluded from the study. The average thickness of the choroid at the fovea and visual acuity by means of Snellen chart were measured. Fourteen healthy subject (HS) age and sex matched were enrolled.
Results: :
The mean ± SD of choroidal thickness were 231 ± 57.6 µm at the fovea for RP patients and 281 ± 58.3 for HS. Subfoveal choroidal thickness did not correlate with visual acuity (0.43 ± 0.35) but the difference in choroidal thickness between HS and RP patiens was statistically significant (r=0.18 and p=0.005 respectively).
Conclusions: :
The foveal choroid in eyes with RP was thinner than HS. 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. In our study population the choroidal thickness did not affect visual function. Further studies are needed in order to evaluate the relation between retinal function and choroidal thickness, in a more complete way, such as microperimetry.
Keywords: choroid • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retinal degenerations: hereditary