title: Reading performance in infantile nystagmus.
abstract: OBJECTIVE
  To characterize reading deficits in infantile nystagmus (IN), to determine optimal font sizes for reading in IN, and to investigate whether visual acuity (VA) and severity of nystagmus are good indicators of reading performance in IN.
  
  
  METHODS
  Prospective cross-sectional study.
  
  
  METHODS
  Seventy-one participants with IN (37 idiopathic, 34 with albinism) and 20 age-matched controls.
  
  
  METHODS
  Reading performance was assessed using Radner reading charts and was compared with near logarithm of the minimum angle of resolution (logMAR) VA, nystagmus intensity, and foveation characteristics as quantified using eye movement recordings.
  
  
  METHODS
  Reading acuity (smallest readable font size), maximum reading speed, critical print size (font size below which reading is suboptimal), near logMAR VA, nystagmus intensity, and foveation characteristics (using the eXpanded Nystagmus Acuity Function).
  
  
  RESULTS
  Using optimal reading conditions, maximum reading speeds were 18.8% slower in albinism and 14.7% slower in idiopathic IN patients compared with controls. Reading acuities were significantly worse (P<0.001) in IN patients compared with controls. Also, the range of font sizes over which reading speeds were less than the optimum were much larger in IN patients compared with controls (P<0.001). Reading acuity was correlated strongly to near VA (r(2) = 0.74 albinism, r(2) = 0.55 idiopathic), but was better than near VA in participants with poor VA. Near VA was a poor predictor of maximum reading speed. Nystagmus intensity and foveation were poor indicators of both reading acuity and maximum reading speed.
  
  
  CONCLUSIONS
  Maximum reading speeds can be near normal in IN when optimal font sizes are provided, even in individuals with poor VA or intense nystagmus. However, reading performance in IN is acutely sensitive to font size limitations. Font sizes for optimal reading speeds in IN may be as much as 6 logMAR lines worse than the near VA.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors: Ophthalmology Group, Faculty of Medicine & Biological Sciences, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors: Niraj
authors: N
authors: Barot
authors: Rebecca J
authors: RJ
authors: McLean
authors: Irene
authors: I
authors: Gottlob
authors: Frank A
authors: FA
authors: Proudlock
mesh_terms: D000328:Adult; D016117:Albinism, Ocular / Q000175:diagnosis / Q000503:physiopathology; D003430:Cross-Sectional Studies; D004410:Dyslexia / Q000175:diagnosis / Q000503:physiopathology*; D005074:Evoked Potentials, Visual / Q000502:physiology; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D020417:Nystagmus, Congenital / Q000175:diagnosis / Q000503:physiopathology*; D011327:Printing / Q000295:instrumentation; D011446:Prospective Studies; D011932:Reading; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology