Abstract
Purpose :
OCT is an important biomarker of Parkinson’s disease (PD), but there is controversial data regarding its findings evaluating the protctive effects of anti-parkinsonian drugs. We prospectively compared the segmented retinal layers and choroid in PD patients and healthy controls (CT). We also compared, for the first time, PD patients receiving (PD+P) with patients not receiving (PD-P) pramipexole treatment.
Methods :
Thirty-eight eyes of 19 patients (9 PD+P, 10 PD-P), and 40 eyes of 20 CT were included. All eyes were examined using SD-OCT (Cirrus, Carl Zeiss, Dublin, CA), and an automated segmentation was performed using Orion™ (Voxeleron LLC, Pleasanton, CA, USA). Measurements included full-thickness and volume of the choroid, retina and the following segmented layers: macular retinal nerve fiber layer (mRNFL), ganglion cell layer+inner plexiform layer (GCL+IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL) and photoreceptor layer (PRL). Global average and ETDRS sectoral parameters were determined. At each sector, measurements were grouped in inner retinal layers (IRL, including RNFL+GCL+IPL+INL) and the remaining outer retinal layers (ORL). Generalized estimating equation was used to compensate inter-eye correlation from the same patient. A p≤0.01 was considered significant.
Results :
There was no difference in demographic characteristics of the groups, except for the time of pramipexole treatment between PD+P and PD-P (Table 1 and 2). Full-thickness measurements revealed significant thinning of the fovea in PD patients (Table 3). The following segmented sectors were also significantly thinner: inferior inner mRNFL; foveal GCL+IPL; foveal and inferior inner ganglion cell complex (GCC, including GCL+IPL+RNFL); foveal IRL and ORL (Table 4). Compared to PD+P, eyes of PD-P patients showed significant thinning of the inferior inner mRNFL, superior outer ONL, inner annulus GCC, inferior inner GCC, and inferior inner IRL (Table 5). There was no significant difference in choroidal thickness and layers volumes.
Conclusions :
Fovea and inner sectors of IRL and ORL are thinner in PD than controls. Segmented OCT layers seem a better biomarker of retinal degeneration in PD than full-thickness. Abnormalities were significantly less prominent in patients receiving Pramipexole treatment suggesting that it may help to prevent retinal thinning in patients with PD.
This is a 2020 ARVO Annual Meeting abstract.