title: A case of Bietti crystalline dystrophy with preserved visual acuity and extinguished electroretinogram: a case report.
abstract: BACKGROUND
  Progressive night blindness and constriction of the visual fields are features of Bietti crystalline corneoretinal dystrophy, but here we report a case with the most probable diagnosis of Bietti crystalline dystrophy and good central visual acuity and severely decreased electroretinogram.
  
  
  METHODS
  The patient was a 28-year-old woman with complaint of decreased vision without night blindness. Her both eyes visual acuity were 20/25 with plano refraction. Fundus examination showed intraretinal crystals distributed in the posterior pole and also midperiphery. Fullfield electroretinogram showed decreased scotopic a and b-wave amplitudes.
  
  
  CONCLUSIONS
  In our patient central foveal region was relatively intact; and this can explain subnormal visual acuity. Although visual acuity was nearly spared, electroretinogram was extremely affected.
authors.affiliation: Department of Ophthalmology, Farabi Eye Research Center South Kargar Street, Tehran, Postal code: 1336616351 Iran. ali2006@yahoo.com
authors.forename: Ali
authors.initials: A
authors.lastname: Tabatabaei
authors.forename: Mohammad
authors.initials: M
authors.lastname: Soleimani
authors.forename: Sasan
authors.initials: S
authors.lastname: Moghimi
authors.forename: Mohammad Yaser
authors.initials: MY
authors.lastname: Kiarudi