August 01, 2004

Pupil Size Again Proven to be a Factor in Night Vision Problems

Pupil size and night vision disturbances after LASIK for myopia

Acta Ophthalmologica Scandinavica
Volume 82, Issue 4, August 2004, Pages 454-460

Helgesen, A., Hjortdal, J., Ehlers, N.

Department of Ophthalmology, Århus University Hospital, Århus, Denmark
Eye Department, Århus Kommunehospital, Nørrebrogade 44, 8000 Århus C, Denmark

Abstract

Purpose:  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 (BSCV A) 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 BSCV A 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).

Conclusion:  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.

 

Posted by Admin at August 1, 2004 06:48 PM