title: Pingelapese achromatopsia: correlation between paradoxical pupillary response and clinical features.
abstract: OBJECTIVE
  To evaluate the paradoxical pupillary constriction in darkness in patients with Pingelapese achromatopsia (PA), and to describe a connection between this phenomenon and the clinical features.
  
  
  METHODS
  27 patients with PA were examined. All underwent a full ophthalmic examination which included Snellen visual acuity and ophthalmoscopy. Colour vision examination was performed with Ishihara pseudoisochromatic plates and also with a colour plate consisting of five basic colours (red, green, purple, yellow, and orange). Paradoxical pupillary response was examined and documented with a special infrared video camera. Pupils' images were analysed using the Scion Image program and the ratio of pupil size in darkness to its size in light was calculated and recorded.
  
  
  RESULTS
  Mean visual acuity was 20/400 (range 20/80-20/800). Colour vision examination showed a mean of 3.2 (SD 1.5) (range 1-5) of Ishihara colour plates, and 0.5 (0.75) (0-3) of basic colour plates. 23 patients (85%) had paradoxical pupillary constriction in darkness. Mean dark/light ratio of pupillary area was 0.86 (range 0.5-1.6). In patients with marked paradoxical pupillary constriction there was a significant correlation of visual acuity and Ishihara score.
  
  
  CONCLUSIONS
  Clinical manifestations of achromatopsia include total colour blindness, low visual acuity (mean of 20/400), horizontal pendular or rotatory nystagmus, and photophobia. Most patients have paradoxical pupillary constriction in darkness. When this response is brisk it seems to correlate with lower visual acuity and lower Ishihara score.
authors.affiliation: The Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel 52621. guybs@barak-online.net
authors.forename: G J
authors.initials: GJ
authors.lastname: Ben Simon
authors.forename: F A
authors.initials: FA
authors.lastname: Abraham
authors.forename: S
authors.initials: S
authors.lastname: Melamed
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003119:Color Perception Tests / Q000379:methods; D003117:Color Vision Defects / Q000150:complications / Q000503:physiopathology*; D003623:Dark Adaptation; D005260:Female; D006801:Humans; D008297:Male; D009759:Nystagmus, Pathologic / Q000150:complications / Q000503:physiopathology; D020795:Photophobia / Q000150:complications / Q000503:physiopathology; D011681:Pupil Disorders / Q000150:complications / Q000503:physiopathology*; D012025:Reflex, Pupillary; D012044:Regression Analysis; D014792:Visual Acuity