CHANGES IN GLARE AND CONTRAST SENSITIVITY AFTER PRK

Background: Morphological changes in the corneal surface after PRK may result not only in refraction fluctuations and reduction in visual ac uity, but also in changes of contrast sensitivity. The aim of this stu dy was to investigate whether PRK has an influence on contrast sensiti vity with and without glare with a subsequent effect on the ability to drive cars. Patients and methods: Anonymous inquiries were made by me ans of a questionnaire sent to 114 patients after bilateral PRK in whi ch the patients were asked to assess subjectly their driving ability. Additionally, in 66 eyes of 66 patients with a mean myopia of -5.3 D, an investigation on contrast sensitivity was performed according to th e recommendations of the DOG (German Ophthalmological Society) using a Rodenstock nyctometer. Results: Postoperatively, 55% of the patients felt more comfortable driving a car than preoperatively, 31% did not r ecognize any change, and 14% felt more uncomfortable driving car. Cont rast sensitivity with or without glare 2 weeks postoperatively was so much reduced in 77% or 53%, respectively, of the patients that the cri teria for driving a car in Germany were not fulfilled.Within the first 12 months after PRK the number of impaired patients diminished but ev en 1 year after PRK the number of patients with reduced contrast sensi tivity with and without glare was higher than before PRK. Surprisingly , however, the criteria for driving a car with respect to contrast sen sitivity with and without glare were not fulfilled even before PRK by as much as 44% and 24% of the patients, respectively. Conclusions: All patients must be in formed about the possible impairment for driving a car before PRK is performed.