title: In Vivo Morphology of the Optic Nerve and Retina in Patients With Parkinson's Disease.
abstract: OBJECTIVE
  To investigate optic nerve (ON) and macular morphology in patients with Parkinson's disease (PD) using spectral-domain optical coherence tomography (SD-OCT).
  
  
  METHODS
  Twenty-five participants with PD (19 males and 6 females; mean age 60.79; SD ± 9.24) and 25 sex-, age-, ethnicity-, and refraction-matched healthy controls.
  
  
  METHODS
  A high-resolution SD-OCT device was used to acquire scans in 25 participants with PD (mean age 60.79; ± SD 9.24) and 25 sex-, age-, ethnicity-, and refraction-matched healthy controls. Main outcome measures included optic nerve head parameters (disc/cup diameters/areas, cup/rim volumes, cup depth, cup/disc ratio; peripapillary retinal nerve fiber layer [ppRNFL] thickness), retinal thickness (in inner and outer annuli around the foveal center) and thickness of individual retinal layers.
  
  
  RESULTS
  Our study showed significant ppRNFL thinning in PD patients in all quadrants (P < 0.05) associated with a shallower optic cup (P = 0.03) as compared with controls. Foveal remodelling with retinal thinning (nasal and temporal segments in both annuli; and superior segment in outer annulus; P < 0.05), foveal pit widening (P = 0.05), central outer plexiform layer (OPL) thickening (P < 0.001), and nasal RPE thinning (P < 0.001) was also found in PD. The differences were more obvious in hemiretinae related to the predominantly affected cerebral hemisphere. Changes were more pronounced in advanced stages and longer PD duration.
  
  
  CONCLUSIONS
  Optic nerve changes in PD are likely to be caused by primary neurodegeneration. Central retinal thinning, pit widening, central OPL thickening, and RPE thinning indicate foveal remodelling. Specific changes of the fovea and thinning of individual retinal layers, correlating with disease severity and duration, indicate that ON and retinal changes have potential to be used as biomarkers for PD.
authors.affiliation: The University of Leicester Ulverscroft Eye Unit University of Leicester, Leicester, United Kingdom.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Pilat
authors.affiliation: The University of Leicester Ulverscroft Eye Unit University of Leicester, Leicester, United Kingdom.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: McLean
authors.affiliation: The University of Leicester Ulverscroft Eye Unit University of Leicester, Leicester, United Kingdom.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Proudlock
authors.affiliation: The University of Leicester Ulverscroft Eye Unit University of Leicester, Leicester, United Kingdom.
authors.forename: Gail D E
authors.initials: GD
authors.lastname: Maconachie
authors.affiliation: The University of Leicester Ulverscroft Eye Unit University of Leicester, Leicester, United Kingdom.
authors.forename: Viral
authors.initials: V
authors.lastname: Sheth
authors.affiliation: School of Life & Health Sciences, Aston University, Birmingham, United Kingdom.
authors.forename: Yusuf A
authors.initials: YA
authors.lastname: Rajabally
authors.affiliation: The University of Leicester Ulverscroft Eye Unit University of Leicester, Leicester, United Kingdom.
authors.forename: Irene
authors.initials: I
authors.lastname: Gottlob
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009898:Optic Disk / Q000473:pathology; D009900:Optic Nerve / Q000473:pathology*; D010300:Parkinson Disease / Q000175:diagnosis*; D011446:Prospective Studies; D012160:Retina / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000473:pathology; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity