Abstract
Abstract: :
Purpose:To observe tear film behavior in early postoperative LASIK, and see if it follows a break up pattern. If there is such pattern, to make a correlation between the pattern with the tear film break up time (BUT) , symptomatology, and corneal topography. Methods:We included 30 eyes of 15 patients without previous ocular pathology or surgery. The patients underwent four photographic sessions.(TOPCON AM-SL camera with Elite Chrome 100 film.) The first session was preoperative, the second session was postoperative on day 3, the third session on day fifteen and the fourth session was on day thirty after the surgery. Patients were stained for the pictures. After the picture was taken we reported the patient symptoms, tear film BUT, and a corneal topography . Results:We included 26 eyes of 13 patients, 4 eyes were excluded for not finishing the sessions. We analyzed a total of 1,666 pictures which after four screen sessions left a total of 264 representative pictures. We observed the following patterns: A) Normal pattern. B) Abnormal patterns: a)Epithelium liability, b) A break up zone without stain. c) Increased thickness of the tear film. d) A dot pattern. e) A lattice pattern. f) A striated pattern. Seventy three percent had a normal pattern preoperatively. On the second session 70% showed any of the abnormal patterns. On the third session only 50% showed the abnormal patterns, and it was until the last session that the patients recovered the normal pattern (77%).The tear BUT decreased on the second session and recovered through the last session. The patient symptoms associated with the tear film were more intense on the third and fourth session. Corneal topography did not change during the 4 sessions. Conclusion:In the preoperative session we did not observe any tear film abnormal pattern ,on the next three sessions tear patterns were observed. Abnormal break up patterns with referred symptoms are seen during the first month postoperatively.There is no relationship between the film behavior and the corneal topography.
Keywords: 548 refractive surgery: LASIK • 550 refractive surgery: optical quality • 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials