Abstract
Purpose :
To determine whether corneal sensation and dry eye parameters are affected by varying flap diameters after myopic laser in situ keratomileusis (LASIK) surgery with a femtosecond laser.
Methods :
This case series study enrolled seven patients (112 eyes), who had undergone femtosecond laser-assisted LASIK surgery at Laser Vision Center, Chang Gung Memorial Hospital, Keelung, Taiwan. The flap diameters were grouped either by actual size or by ratio to cornea diameter. For corneal sensitivity measurement, Cochet-Bonnet esthesiometry was performed on the central cornea preoperatively and at 1 and 3 months postoperatively. Dry-eye parameters were evaluated at the same time points by fluorescein corneal staining, Rose Bengal conjunctival staining, tear break-up time, and basic Schirmer test.
Results :
Before adjustment, there was no significant difference between the two groups (cut-off flap diameter set at 8.7mm) in all tested parameters including corneal sensitivity and dry eye syndrome before surgery and at post-op 1 and 3 months follow up. However, after adjustment with cornea diameter (cut-off ratio set at 0.756), the group that had larger flap / cornea diameter ratio showed significantly decreased basic Schirmer test value (7.52±4.43 mm) than the smaller group (12.15±8.14 mm) at 3 months postoperatively (P=0.006). Other parameters were not significantly different before surgery and at post-op 1 and 3 months follow up.
Conclusions :
Our study indicated that the severity of post-LASIK dry eye syndrome was correlated with flap diameter when the corneal diameter was taken into consideration.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.