title: Peripapillary retinal vessel diameter correlates with mfERG alterations in retinitis pigmentosa.
abstract: OBJECTIVE
  To investigate relationship between the peripapillary retinal vessel diameter and the residual retinal function, measured by mfERG, in patients with retinitis pigmentosa (RP).
  
  
  METHODS
  A cross-sectional study based on 23 patients with RP (43 eyes) and 20 controls (40 eyes) was performed. Retinal vessel diameters were measured using a computer-based program of the retinal vessel analyser (RVA; IMEDOS Systems UG, Jena, Germany). We evaluated the mean diameter in all four major retinal arterioles (D-A) and venules (D-V) within 1.0-1.5 optic disc diameters from the disc margin. The data were compared with the N1 amplitudes (measured from the baseline to the trough of the first negative wave), with the N1P1 amplitudes (measured from the trough of the first negative wave to the peak of the first positive wave) of the mfERG overall response and with the mfERG responses averaged in zones [zone 1 (0°-3°), zone 2 (3°-8°), zone 3 (8°-15°) and zone 4 (15°-24°)].
  
  
  RESULTS
  Mean (±SD) D-A and D-V were narrower in patients with RP [84.86 μm (±13.37 μm) and 103.35 μm (±13.65 μm), respectively] when compared to controls [92.81 μm (±11.49 μm) and 117.67 μm (±11.93 μm), respectively; the p-values between groups were p = 0.003 for D-A and p < 0.001 for D-V, linear mixed-effects model]. The RP group revealed clear differences compared to the controls: D-A and D-V became narrower with reduced mfERG responses. D-V correlated significantly with the overall mfERG N1 amplitudes (p = 0.013) and with N1P1 amplitudes (p = 0.016). D-V correlated with the mfERG amplitudes averaged in zones: (zone 2, 3 and 4; p ≤ 0.040) and N1P1 mfERG amplitudes (zones 1, 2, 3 and 4; p ≤ 0.013).
  
  
  CONCLUSIONS
  Peripapillary retinal vessel diameter is reduced in RP proportionally to functional alterations.
authors: Department of Ophthalmology, University of Basel, Basel, Switzerland.
authors: Lisette T
authors: LT
authors: Lopez Torres
authors: Department of Ophthalmology, University of Basel, Basel, Switzerland.
authors: Cengiz
authors: C
authors: Türksever
authors: Department of Ophthalmology, University of Basel, Basel, Switzerland.
authors: Andreas
authors: A
authors: Schötzau
authors: Department of Ophthalmology, University of Basel, Basel, Switzerland.
authors: Selim
authors: S
authors: Orgül
authors: Department of Ophthalmology, University of Basel, Basel, Switzerland.
authors: Margarita G
authors: MG
authors: Todorova
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000098:blood supply*; D010781:Photography; D012160:Retina / Q000503:physiopathology*; D012171:Retinal Vessels / Q000473:pathology*; D012174:Retinitis Pigmentosa / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology
keywords: mfERG; retinal function; retinal vessel diameter; retinitis pigmentosa