[Lasik, PRK and quality of vision: a study of prognostic factors and a satisfaction survey]

To confirm the clinical interest of pupillary diameter measurement for selecting indications and determining surgical protocols, to look for clinical factors predisposing to night vision symptoms, and to the assess patient satisfaction level for photoablation techniques not based on aberrometry.

This retrospective study was conducted on 111 consecutive myopic patients (219 eyes, with a mean spherical equivalent of -4.25+/-1.84 D); they underwent Lasik (91.3% of cases) or photorefractive keratectomy, after having their pupillary diameter measured by the Colvard pupillometer. Clinical data were collected from medical files, and an anonymous questionnaire was sent in order to assess quality of vision and postoperative satisfaction.

Preoperative aims were reached (r=0.41, p<0.0001). The response rate for the questionnaire was 81.1%. Daytime vision was the same or better for 91.1% of the patients, but 25.6% had worse night vision than before. Night vision symptoms were mentioned by 46.7% of the patients, and the most frequent complaint was halos. However, 97.8% of the patients declared themselves as satisfied and would recommend such surgery to their family and friends. A preoperative myopia greater than 4.50D (RR=1.52, p<0.05) and a postoperative keratometry greater than 8.44 mm (RR=1.62, p<0.05) were risk factors for having night vision symptoms, but pupillary diameter was not a risk factor.

This survey gives an indirect confirmation of the interest of scotopic pupillary diameter measurement and taking it into account in photoablation protocols. However, night vision symptoms remain frequent but do not influence patient satisfaction. Knowledge of risk factors and technical progress should provide a better quality of vision after Lasik.