title: Witnessing the first sign of retinitis pigmentosa onset in the allegedly normal eye of a case of unilateral RP: a 30-year follow-up.
abstract: A patient initially presented with constricted visual field, attenuated retinal vasculature, pigmentary clumping and reduced ERG in OS only, suggestive of unilateral retinitis pigmentosa (RP). This patient was subsequently seen on eight occasions (over three decades), and, with time, the initially normal eye (OD) gradually showed signs of RP-like degeneration. The purpose of this study was to evaluate which clinical modality (visual field, funduscopy or electroretinography) could have first predicted this fate.
  
  
  
  At each time points, data obtained from our patient were compared to normative data using Z tests.
  
  
  
  At initial visit, all tests were significantly (p < 0.05) altered in OS and normal in OD. Visual field and retinal vessel diameter in OD reduced gradually to reach statistical significance at the 5th visit and 6th visit (21 and 22 years after the first examination, respectively). In OD, the amplitude of the scotopic and photopic ERGs reduced gradually and was significantly smaller than normal at the 2nd visit (after 11 years) and 3rd visit (after 18 years), respectively. When the photopic ERG was analyzed using the discrete wavelet transform (DWT), we were able to detect a significant change at the 2nd visit (after 11 years) instead of the 3rd visit (18 years).
  
  
  
  Our study allowed us to witness the earliest manifestation of an RP disease process. The ERG was the first test to detect significant RP changes. A significantly earlier detection of ERG anomalies was obtained when the DWT was used, demonstrating its advantage for early detection of ERG changes.
authors.affiliation: Department of Ophthalmology and Neurology-Neurosurgery, McGill University - Montreal Children's Hospital Research Institute, Montreal, QC, Canada.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Gauvin
authors.affiliation: Department of Ophthalmology and Neurology-Neurosurgery, McGill University - Montreal Children's Hospital Research Institute, Montreal, QC, Canada.
authors.forename: Hadi
authors.initials: H
authors.lastname: Chakor
authors.affiliation: Department of Ophthalmology and Neurology-Neurosurgery, McGill University - Montreal Children's Hospital Research Institute, Montreal, QC, Canada.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Koenekoop
authors.affiliation: Department of Ophthalmology and Neurology-Neurosurgery, McGill University - Montreal Children's Hospital Research Institute, Montreal, QC, Canada.
authors.forename: John M
authors.initials: JM
authors.lastname: Little
authors.affiliation: Département de génie électrique, École de Technologie Supérieur, Montreal, QC, Canada.|Centre de Recherches Mathématiques, Montreal, QC, Canada.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Lina
authors.affiliation: Department of Ophthalmology and Neurology-Neurosurgery, McGill University - Montreal Children's Hospital Research Institute, Montreal, QC, Canada. Pierre.lachapelle@mcgill.ca.|Research Institute of the McGill University Health Centre, 1001 Boul. Décarie, Glen Site, Block E, Program Mail Drop Point #EM03211 - Office #EM03238, Montreal, QC, H4A 3J1, Canada. Pierre.lachapelle@mcgill.ca.
authors.forename: Pierre
authors.initials: P
authors.lastname: Lachapelle
mesh_terms: D000328:Adult; D004596:Electroretinography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D009887:Ophthalmoscopy / Q000379:methods*; D012174:Retinitis Pigmentosa / Q000175:diagnosis*; D014786:Vision Disorders / Q000175:diagnosis; D014792:Visual Acuity; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology
keywords: Electroretinogram; Human; Retinal vasculature; Retinitis pigmentosa; Time–frequency; Unilateral; Visual field; Wavelet transform