title: The association between multifocal electroretinograms and OCT retinal thickness in retinitis pigmentosa patients with good visual acuity.
abstract: OBJECTIVE
  To investigate relationships between retinal morphology and retinal function in patients with retinitis pigmentosa (RP) using optical coherence tomography (OCT) and multifocal electroretinography (mfERG).
  
  
  METHODS
  In all, 14 patients with RP who had visual acuities of 0.2 logMAR or better and Humphrey central fields of 10 degrees or larger participated in the study along with 16 normal control subjects. The amplitudes and timings of the mfERG responses were compared with spatially corresponding measures of retinal layer thickness from OCT within the macula region (central 12 degrees ).
  
  
  RESULTS
  Eyes with RP showed thinning of the photoreceptor retinal (PR) layer and thickening of mid-inner retinal (MIR) layers beyond the fovea. mfERG amplitude was reduced in all regions, whereas mfERG timing was only significantly delayed at a retinal eccentricity of 6-12 degrees and was otherwise preserved within the foveal and parafoveal retina (0-6 degrees). PR layer thickness was correlated with mfERG amplitude across the macula region. mfERG timing was correlated with the total change in retinal thickness (combined PR thinning and MIR thickening) at an eccentricity of 6-12 degrees.
  
  
  CONCLUSIONS
  The relationship between mfERG timing and retinal thickness in RP is dependent on the retinal eccentricity. Preserved timing in the central retina (0-6 degrees ), despite significant disruption to retinal laminar structure, could be suggestive of inner retinal remodelling or functional redundancy. Cone system activity derived from mfERG amplitude appears to be related to the thickness of the photoreceptor layer in the macula region.
authors.affiliation: Vision Science Research Group, Department of Optometry, University of Ulster, Coleraine, UK. wolsley-c@email.ulster.ac.uk
authors.forename: C J
authors.initials: CJ
authors.lastname: Wolsley
authors.forename: G
authors.initials: G
authors.lastname: Silvestri
authors.forename: J
authors.initials: J
authors.lastname: O'Neill
authors.forename: K J
authors.initials: KJ
authors.lastname: Saunders
authors.forename: R S
authors.initials: RS
authors.lastname: Anderson
mesh_terms: D000293:Adolescent; D000328:Adult; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012160:Retina / Q000473:pathology*; D012174:Retinitis Pigmentosa / Q000473:pathology* / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult