title: Effects of levodopa on retina in Parkinson disease.
abstract: OBJECTIVE
  To evaluate the effects of levodopa on retina, we assessed retina with optical coherence tomography (OCT) in Parkinson disease (PD).
  
  
  METHODS
  Thirty-five patients with PD (17 with levodopa monotherapy, 18 untreated) and 11 healthy controls were included in this cross-sectional study. Unified Parkinson's Disease Rating Scale (UPDRS) and Hoehn & Yahr (H&Y) staging scale were used for the evaluation of disease severity. All retinal scans were performed using OCT.
  
  
  RESULTS
  Total UPDRS and motor subscores were lower in untreated patients compared to patients with treated PD (p = 0.013, p = 0.033, respectively). There was no significant difference in the range of H&Y stages between the untreated and treated PD groups (p = 0.342). The average retinal nerve fiber layer thickness of the untreated (106.76 ± 10.55 µm) and treated (104.62 ± 8.23 µm) patients with PD were significantly thinner than those of controls (115.60 ± 9.11 µm) (p<0.005). However, there was no significant difference between the untreated and patients with treated PD (p = 0.780). No significant difference in mean values of average thickness of ganglion cell complex layer was observed among controls, patients with untreated PD, and patients with treated PD (p = 0.304).
  
  
  CONCLUSIONS
  Although the disease in patients with treated PD was more severe than in the untreated group, no significant difference in the thickness of retina was found between the 2 groups. Therefore, we thought that levodopa might have a protective effect on retina in patients with PD.
authors.affiliation: 1 Neurology Department, Bakirkoy Research and Training Hospital for Psychiatry, Neurology and Neurosurgery, Istanbul - Turkey.
authors.forename: Aysu
authors.initials: A
authors.lastname: Sen
authors.forename: Betul
authors.initials: B
authors.lastname: Tugcu
authors.forename: Cigdem
authors.initials: C
authors.lastname: Coskun
authors.forename: Cansu
authors.initials: C
authors.lastname: Ekinci
authors.forename: Senay Asik
authors.initials: SA
authors.lastname: Nacaroglu
mesh_terms: D000328:Adult; D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000187:drug effects / Q000473:pathology; D010300:Parkinson Disease / Q000145:classification / Q000188:drug therapy*; D012160:Retina / Q000187:drug effects* / Q000473:pathology; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000473:pathology; D041623:Tomography, Optical Coherence
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa