title: Bioelectrical function and structural assessment of the retina in patients with early stages of Parkinson's disease (PD).
abstract: OBJECTIVE
  To determine bioelectrical function and structural changes of the retina in patients with early stages of Parkinson's disease (PD).
  
  
  METHODS
  Thirty-eight eyes of 20 patients with early idiopathic PD and 38 eyes of 20 healthy age- and sex-matched controls were ophthalmologically examined, including assessment of distance best-corrected visual acuity (DBCVA), slit lamp examination of the anterior and posterior segment of the eye, evaluation of the eye structures: paramacular retinal thickness (RT) and retinal nerve fiber layer (RNFL) thickness with the aid of OCT, and the bioelectrical function by full-field electroretinogram (ERG). Additionally, PD patients were interviewed as to the presence of dopamine-dependent visual functions abnormalities.
  
  
  RESULTS
  In patients with early PD, statistically significant changes in comparison with the control group were observed in ERG. They contained a reduction in mean amplitudes of the scotopic a-wave (rod-cone response), the scotopic oscillatory potentials (OPs)--OP2 and OP3, the photopic b-wave, and a reduction in the overall index (OP1 + OP2 + OP3) and a prolongation of mean peak times of the scotopic OP1, OP2, OP3, OP4 (p < 0.05). A questionnaire concerning abnormalities of dopamine-dependent visual functions revealed that PD patients with abnormal peak times of OP1, OP2, and OP3 reported non-specific visual disturbances more frequently in comparison with PD patients with normal peak times of OPs. Other analyzed parameters of ERG, DBCVA, RT, and RNFL did not significantly differ between patients with PD and the control group.
  
  
  CONCLUSIONS
  In patients with early PD, bioelectrical dysfunction of the retina was observed in the ERG test, probably as a result of dopamine deficiency in the retina. The results of our study indicate that ERG may also be a useful tool for understanding the reason for non-specific visual disturbances occurring in PD patients.
authors.affiliation: Department of Ophthalmology, Pomeranian Medical University, Powstancow Wlkp. 72, 70-111, Szczecin, Poland. barbara_nowacka@vp.pl.
authors.forename: Barbara
authors.initials: B
authors.lastname: Nowacka
authors.affiliation: Department of Ophthalmology, Pomeranian Medical University, Powstancow Wlkp. 72, 70-111, Szczecin, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Lubiński
authors.affiliation: Department of Neurology, Pomeranian Medical University, Szczecin, Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Honczarenko
authors.affiliation: Department of Clinical Psychology, University of Szczecin, Szczecin, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Potemkowski
authors.affiliation: Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Szczecin, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Safranow
mesh_terms: D000328:Adult; D000368:Aged; D055724:Electrophysiological Phenomena / Q000502:physiology*; D004596:Electroretinography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055254:Night Vision / Q000502:physiology; D009991:Oscillometry; D010300:Parkinson Disease / Q000503:physiopathology*; D012160:Retina / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology
keywords: ERG; OCT; Parkinson’s disease; Retinal bioelectrical function and structure