Pupil size and night vision disturbances after LASIK for myopia.
OBJECTIVE
To examine whether standardized, preoperative evaluation of pupil sizes can predict the risk of night vision visual disturbances after bilateral laser in situ keratomileusis (LASIK) for myopia.


METHODS
A prospective study was carried out involving 46 patients who underwent bilateral LASIK for myopia. Pupil sizes were measured before surgery using an infrared pupillometer under standardized settings. Pre- and postoperative refraction and best spectacle-corrected visual acuity (BSCVA) were registered. At the 3-month follow-up visit, the patients completed a questionnaire regarding night vision pre- and postoperatively.


RESULTS
The mean bilateral, spherical equivalent refraction (SE) was - 8.76 D (range 6.32 to - 12.0 D) preoperatively, and - 1.69 D (range 0 to - 4.38 D) postoperatively. The mean bilateral BSCVA was not changed by the operations. We found a significant correlation between large scotopic pupil sizes and the impression of worsened night vision (p < 0.01). A significant correlation between gender (males) and subjectively reduced night vision postoperatively was also found (p < 0.05).


CONCLUSIONS
Large pupil size measured preoperatively is correlated with an increased frequency of subjectively experienced post-LASIK visual disturbances during scotopic conditions. We recommend preoperative evaluation of pupil size in all patients prior to LASIK surgery.
Department of Ophthalmology, Arhus University Hospital, Arhus, Denmark.
Andreas
A
Helgesen
Jesper
J
Hjortdal
Niels
N
Ehlers
D000328:Adult; D003623:Dark Adaptation; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D009755:Night Blindness / Q000209:etiology* / Q000503:physiopathology*; D011446:Prospective Studies; D011680:Pupil / Q000502:physiology*; D012029:Refraction, Ocular; D011795:Surveys and Questionnaires; D014792:Visual Acuity