title: Localized retinal electrophysiological and fundus autofluorescence imaging abnormalities in maternal inherited diabetes and deafness.
abstract: OBJECTIVE
  To investigate retinal function in patients with maternally inherited diabetes and deafness (MIDD) and to correlate the findings with fundus autofluorescence (FAF) imaging.
  
  
  METHODS
  FAF was imaged in five patients (age range, 49-60 years) confirmed to have the mitochondrial DNA nucleotide A3243G point mutation. Retinal function was measured by full-field (Ganzfeld) electroretinography (ERG) and pattern ERG, incorporating the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. Multifocal ERG (mfERG) was also performed. For analysis of the mfERG data, five regional ring groups of equal eccentricity were formed. For each ring, the peak amplitude (defined as the difference between P1 and N1) and the implicit time of P1 were determined and compared with normative values.
  
  
  RESULTS
  Visual acuity in the patients was between 20/20 and 20/40 (Early Treatment Diabetic Retinopathy Study [ETDRS] chart). Irregular increased FAF signals were observed adjacent to and between areas of atrophy of the retinal pigment epithelium (RPE). Ganzfeld ERGs were within normal limits in three patients. Pattern ERG was abnormal in five eyes of three patients. mfERG peak amplitude abnormalities were particularly present in rings 2 and 3 and were consistent with the distribution of FAF abnormalities. In all but one eye, no implicit times changes were present.
  
  
  CONCLUSIONS
  Significant mfERG abnormalities with normal Ganzfeld ERG are consistent with nonuniform damage to the central retina in MIDD, in keeping with the FAF findings. Reduced peak amplitudes with normal implicit times in the mfERG suggest localized loss of function and may indicate damage to the cone photoreceptor outer segments or cone photoreceptor loss in MIDD.
authors.affiliation: Moorfields Eye Hospital, London, United Kingdom.
authors.forename: Caren
authors.initials: C
authors.lastname: Bellmann
authors.forename: Magella M
authors.initials: MM
authors.lastname: Neveu
authors.forename: Hendrik P N
authors.initials: HP
authors.lastname: Scholl
authors.forename: Chris R
authors.initials: CR
authors.lastname: Hogg
authors.forename: Pamela P
authors.initials: PP
authors.lastname: Rath
authors.forename: Sharon
authors.initials: S
authors.lastname: Jenkins
authors.forename: Alan C
authors.initials: AC
authors.lastname: Bird
authors.forename: Graham E
authors.initials: GE
authors.lastname: Holder
mesh_terms: D004272:DNA, Mitochondrial / Q000235:genetics; D003638:Deafness / Q000235:genetics* / Q000503:physiopathology; D003920:Diabetes Mellitus / Q000235:genetics* / Q000503:physiopathology; D004594:Electrophysiology; D004596:Electroretinography; D005260:Female; D005453:Fluorescence; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D008875:Middle Aged; D017354:Point Mutation / Q000235:genetics; D012160:Retina / Q000503:physiopathology*; D012162:Retinal Degeneration / Q000235:genetics* / Q000503:physiopathology*; D014792:Visual Acuity
chemical_list: D004272:DNA, Mitochondrial