title: Fixation pattern analysis with microperimetry in nystagmus patients.
abstract: OBJECTIVE
  To assess the usefulness of microperimetry (MP) as an additional objective method for characterizing the fixation pattern in nystagmus.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Fifteen eyes of 8 subjects (age, 12-80 years) with nystagmus from the Lluís Alcanyís Foundation (University of Valencia, Spain) were included.
  
  
  METHODS
  All patients had a comprehensive ophthalmologic examination including a microperimetric examination (MAIA, CenterVue, Padova, Italy). The following microperimetric parameters were evaluated: average threshold (AT), macular integrity index (MI), fixating points within a circle of 1° (P1) and 2° of radius (P2), bivariate contour ellipse area (BCEA) considering 63% and 95% of fixating points, and horizontal and vertical axes of that ellipse.
  
  
  RESULTS
  In monocular conditions, 6 eyes showed a fixation classified as stable, 6 eyes showed a relatively unstable fixation, and 3 eyes showed an unstable fixation. Statistically significant differences were found between the horizontal and vertical components of movement (p = 0.001), as well as in their ranges (p < 0.001). Intereye comparison showed differences between eyes in some subjects, but only statistically significant differences were found in the fixation coordinates X and Y (p < 0.001). No significant intereye differences were found between microperimetric parameters. Between monocular and binocular conditions, statistically significant differences in the X and Y coordinates were found in all eyes (p < 0.02) except one. No significant differences were found between MP parameters for monocular or binocular conditions. Strong correlations of corrected distance visual acuity (CDVA) with AT (r = 0.812, p = 0.014), MI (r = -0.812, p = 0.014), P1 (r = 0.729, p = 0.002), horizontal diameter of BCEA (r = -0.700, p = 0.004), and X range (r = -0.722, p = 0.005) were found.
  
  
  CONCLUSIONS
  MP seems to be a useful technology for the characterization of the fixation pattern in nystagmus, which seems to be related to the level of visual acuity achieved by the patient.
authors.affiliation: Optometric Clinic, Lluis Alcanyís Foundation, University of Valencia, Valencia, Spain.
authors.forename: Ainhoa
authors.initials: A
authors.lastname: Molina-Martín
authors.affiliation: Department of Ophthalmology (OFTALMAR), Vithas Medimar International Hospital, Alicante, Spain; Department of Optics, Anatomy and Pharmacology, University of Alicante, Alicante, Spain. Electronic address: dpinero@oftalmar.es.
authors.forename: David P
authors.initials: DP
authors.lastname: Piñero
authors.affiliation: Department of Ophthalmology (OFTALMAR), Vithas Medimar International Hospital, Alicante, Spain.
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Pérez-Cambrodí
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D023882:Dominance, Ocular / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000503:physiopathology*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology