title: Presbyopia complicating pre-existing strabismus.
abstract: BACKGROUND
  Presbyopia may affect pre-existing sensory adaptations or aggravate previously asymptomatic heterophoria. We describe the presentation, underlying problem and management of 11 patients with pre-existing strabismus or heterophoria who presented with new symptoms of double vision attributable to presbyopic change, an association not previously reported.
  
  
  METHODS
  Patients with new strabismic symptoms attributable to presbyopia were recruited prospectively over a 1-year period.
  
  
  RESULTS
  The 11 patients had had a recent decrease of accommodative amplitude that resulted in blurred vision at near with a breakdown of pre-existing heterophoria (2 patients), alteration of fixation pattern (6 patients), symptomatic alternating fixation (2 patients) or intolerance to correction owing to restrictive strabismus (1 patient).
  
  
  CONCLUSIONS
  At the onset of presbyopia, symptoms may be varied and subtle. Ophthalmologists and orthoptists should carefully determine the exact nature of the symptoms. Any pre-existing fixation pattern should then be established from the history, old photographs or suppression characteristics. Refractive or surgical management should be aimed at returning the patient to his or her long-standing sensory adaptation. Other important issues, such as incomplete correction of hypermetropia by refractive surgery and problems using bifocals with vertical restrictive strabismus, should be noted.
authors.affiliation: Department of Ophthalmology, University of British Columbia, British Columbia's Children's Hospital, Vancouver, BC.
authors.forename: Darren T
authors.initials: DT
authors.lastname: Oystreck
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lyons
mesh_terms: D000065:Accommodation, Ocular; D000328:Adult; D001251:Astigmatism / Q000150:complications; D004172:Diplopia / Q000209:etiology; D004948:Esotropia / Q000150:complications; D005099:Exotropia / Q000150:complications; D005139:Eyeglasses; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D006956:Hyperopia / Q000150:complications; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D011446:Prospective Studies; D013285:Strabismus / Q000150:complications* / Q000628:therapy