Parkinson´s disease and retinal optical coherence tomography

AbstractPurpose The aim of the study was to assess the retinal measurements and optic nerve head (ONH) morphology in patients with Parkinson's disease (PD) and to determine whether there is any correlation among these parameters and the disease´s duration.Methods Thirty patients affected by PD (mean age 67,3 ± 8,4; range: 49 ‐ 83) were compared with 28 age‐matched controls. In all subjects, peripapillary retinal nerve fiber layer (RNFL) thickness, ONH measurements, and macular thickness and volume were measured by optical coherence tomography (OCT).Results PD patients showed a statistically significant reduction of the overall peripapillary RNFL thickness [95±9µm, range: 73‐117] compared with those values observed in control eyes [103±7µm, range:87‐117] (p<0.0001, Mann‐Whitney U test). Furthermore, a statistically significant reduction of RNFL thickness was observed in nasal [74±20µm, range:18‐114](p=0.004), inferior [118±14µm, range:88‐147] (p<0.0001) and superior quadrants [120±13µm, range:88‐145] in PD patients when compared with controls [84±14µm, range:54‐106], [132±14µm, range:101‐165] and [125±13µm, range:101‐151] respectively (p=0.023; Mann‐Whitney U test). The temporal peripapillary quadrant, ONH measurements, macular thickness and volume did not reveal any statistically significant differences between both groups.Conclusion PD patients show a decreased peripapillary RNFL thickness evaluated by OCT. We also observe that the further evolution of PD, the lower average peripapillary RNFL thickness. Our results suggest that axonal degeneration could be present in the retina of PD patients and that RNFL thickness measured by OCT could be used as a biomarker for early diagnosis and for monitoring PD progression.