Clinical Course, Genetic Etiology, and Visual Outcome in Cone and Cone-Rod Dystrophy

Alberta Thiadens, TML Phan, RC Zekveld-Vroon, BP Leroy, LI van den Born, CB (Carel) Hoyng, Caroline Klaver, S Roosing, JWR Pott, MJ van Schooneveld, N van Moll-Ramirez, MM van Genderen, CJF Boon, AI Hollander, Arthur Bergen, E De Baere, FPM Cremers, AJ Lotery

Research output: Contribution to journalArticleAcademicpeer-review

101 Citations (Scopus)


Objective: To evaluate the clinical course, genetic etiology, and visual prognosis in patients with cone dystrophy (CD) and cone-rod dystrophy (CRD). Design: Clinic-based, longitudinal, multicenter study. Participants: Consecutive probands with CD (N = 98), CRD (N = 83), and affected relatives (N = 41 and N = 17, respectively) from various ophthalmogenetic clinics in The Netherlands, Belgium, and the United Kingdom. Methods: Data on best-corrected Snellen visual acuity, color vision, ophthalmoscopy, fundus photography, Goldmann perimetry, and full-field standard electroretinogram (ERG) from all patients were registered from medical charts over a mean follow-up of 19 years. The ABCA4, CNGB3, KCNV2, PDE6C, and RPGR genes were analyzed by direct sequencing in autosomal recessive (AR) and X-linked (XL), respectively. Genotyping was not undertaken for autosomal-dominant cases. Main Outcome Measures: The 10-year progression of all clinical parameters and cumulative lifetime risk of low vision and legal blindness were assessed. Results: The mean age onset for CD was 16 years (standard deviation, 11), and of CRD 12 years (standard deviation, 11; P = 0.02). The pattern of inheritance was AR in 92% of CD and 90% of CRD. Ten years after diagnosis, 35% of CD and 51% of CRD had a bull's eye maculopathy; 70% of CRD showed absolute peripheral visual field defects and 37% of CD developed rod involvement on ERG. The mean age of legal blindness was 48 (standard error [SE], 3.1) years in CD, and 35 (SE, 1.1; P < 0.001) years in CR Conclusions: Although CD had a slightly more favorable clinical course than CRD, both disorders progressed to legal blindness in the majority of patients. Mutations in the ABCA4 gene and early onset of disease were independent prognostic parameters for visual loss. Our data may serve as an aid in counseling patients with progressive cone disorders. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references. Ophthalmology 2012;119:819-826 (C) 2012 by the American Academy of Ophthalmology.
Original languageUndefined/Unknown
Pages (from-to)819-826
Number of pages8
Issue number4
Publication statusPublished - 2012

Research programs

  • EMC NIHES-01-64-01
  • EMC OR-01-60-01

Cite this