title: Dark-adapted Pupil Sizes in a Prospective Evaluation of Laser in situ Keratomileusis Patients.
abstract: OBJECTIVE
  This study presents the results of scotopic pupil size measurement in a group of laser in situ keratomileusis (LASIK) patients and the implications this value has for night vision symptoms and treatment zones.
  
  
  METHODS
  This was a prospective study measuring the dark-adapted pupil of 218 patients using a handheld pupillometer.
  
  
  RESULTS
  The mean scotopic pupil size was 5.66 mm with a standard deviation of 1.04 mm. Pupils ranged in size from 3.00 mm to 9.00 mm.
  
  
  CONCLUSIONS
  Results suggest that a number of patients may have seotopic pupil size well beyond the treatment zones commonly used or available in refractive laser systems. Treating with an ablation zone that is smaller than the mesopic pupil will often result in night vision disturbances. Next generation technology such as the Nidek EC-5000 excimer laser can incorporate larger treatment diameters in order to reduce the incidence of halos and glare at night. [J Refract Surg 2000; 16(suppl):S239-S241].
authors.forename: D J
authors.initials: DJ
authors.lastname: Schumer
authors.forename: H S
authors.initials: HS
authors.lastname: Bains
authors.forename: K L
authors.initials: KL
authors.lastname: Brown