Articles about Eye Health and Disease 2003
 

Quality of vision after Lasik: Influence of dioptric correction and pupil size on visual function

(From Yuan-Chieh Lee, MD, et al., J Cataract Refract Surg 2003; 29:769–777.)

The purpose of this study was to determine the influence of pupil size and the amount of ablation on visual performance and on the patient’s perception of glare or halo after laser in situ keratomileusis (LASIK). This study included a random cross-section of 50 eyes of 32 patients with “uniform” topography at least 6 months after LASIK and 51 eyes of 28 patients who had normal corneas. Each LASIK patient completed a survey rating adverse effects such as symptoms of night glare and halo. Pupil diameter and best spectacle-corrected visual acuity (BSCVA) were measured under photopic (daylight) and scotopic (nighttime) conditions. Contrast sensitivity was measured under daytime and nighttime and with night glare conditions.

Results:

• No significant difference was found between the post-LASIK and normal cornea groups in photopic or scotopic best corrected visual acuity
  (P >.05).

• In cases of moderate myopia, the post-LASIK group had decreased contrast sensitivity (P <.05).

• In cases of high myopia, the post-LASIK group had decreased contrast sensitivity under daytime conditions and under nighttime conditions
  (P <.05).

• Glare or halo symptoms did not correlate with scotopic best corrected visual acuity or nighttime contrast sensitivity with or without glare
  (P >.05).

• Pupil size was not significantly correlated with glare or halo symptoms, best corrected visual acuity, or contrast sensitivity under scotopic or photopic conditions (P >.05).

• In moderate myopia, the amount of attempted correction of the spherical equivalent (SE) was correlated with halo symptoms.

• In high myopia, the amount of attempted astigmatism correction was correlated with the development of glare symptoms.

Conclusions: There was a decrease in contrast sensitivity in post-LASIK eyes. The amount of attempted correction of the nearsightedness or astigmatism was correlated with the development of glare and halo symptoms. Pupil size was not significantly correlated with glare or halo symptoms, best corrected visual acuity, or contrast sensitivity in post-LASIK patients with “uniform” topography who had scotopic pupils not larger than 7.0 mm.

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