title: Prevalence of foveal lesions in type 1 and type 2 Usher's syndrome.
abstract: OBJECTIVE
  To evaluate possible differences in the prevalence of clinically detectable foveal lesions between patients with type 1 and type 2 Usher's syndrome.
  
  
  METHODS
  Records of 48 patients with type 1 and 98 patients with type 2 Usher's syndrome were retrospectively evaluated for the presence of a foveal lesion. The age, gender, and racial distribution of patients were similar in the two subtypes. Two investigators reviewed fundus photographs from all patients and, when available, fluorescein angiograms.
  
  
  RESULTS
  In the 48 patients with type 1 Usher's syndrome, 30 (62%) showed a clinically apparent atrophic- or cystic-appearing foveal lesion, whereas in the 98 patients with type 2 Usher's syndrome, 33 (34%) had either an atrophic- or a cystic-appearing foveal lesion. Logistic regression analysis showed that the probability of exhibiting a foveal lesion in both type 1 and type 2 Usher's syndrome increases with age and that patients with type 1 Usher's syndrome are more likely to have a foveal lesion than are patients with type 2 Usher's syndrome.
  
  
  CONCLUSIONS
  Patients with type 1 Usher's syndrome show a greater probability of having either an atrophic- or cystic-appearing foveal lesion than do patients with type 2 Usher's syndrome. This higher prevalence of foveal lesions is consistent with a previous observation that the severity of visual acuity impairment with age is greater for patients with type 1 than type 2 Usher's syndrome. These data are useful in counseling such patients as to their prognosis for central visual function.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois, Chicago College of Medicine, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Fishman
authors.forename: R J
authors.initials: RJ
authors.lastname: Anderson
authors.forename: B L
authors.initials: BL
authors.lastname: Lam
authors.forename: D J
authors.initials: DJ
authors.lastname: Derlacki
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001284:Atrophy; D002648:Child; D003560:Cysts / Q000473:pathology; D003638:Deafness / Q000145:classification / Q000150:complications* / Q000235:genetics; D005260:Female; D005451:Fluorescein Angiography; D005584:Fovea Centralis / Q000473:pathology*; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012044:Regression Analysis; D012164:Retinal Diseases / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D012174:Retinitis Pigmentosa / Q000145:classification / Q000150:complications* / Q000235:genetics; D012189:Retrospective Studies; D013577:Syndrome