Related Experiment Video
Updated: Aug 24, 2026
Corneal Sensitivity Testing Procedure for Ophthalmologic and Optometric Patients
Published on: August 2, 2024
Effect of hinge width on corneal sensation and dry eye after laser in situ keratomileusis
Eric D Donnenfeld1, Michael Ehrenhaus, Renée Solomon
1Department of Ophthalmology, Nassau University Medical Center, Nassau, NY, USA. eddoph@aol.com
Purpose:
To investigate the effect of hinge width on corneal sensation and dry-eye syndrome after laser in situ keratomileusis (LASIK).
Setting:
TLC Laser Eye Center, Garden City, New York, USA.
Methods:
Fifty-four patients at least 18 years of age had bilateral LASIK with a narrow nasal hinge microkeratome flap in 1 eye and a wider nasal hinge microkeratome flap in the other eye. In all eyes, the flaps were 160 microm in thickness with a diameter of 9.5 mm. Masked Cochet-Bonnet esthesiometry was performed in the central cornea preoperatively and at 1 week and 1, 3, and 6 months. Dry eye was evaluated at the same intervals by lissamine green corneal and conjunctival staining, Schirmer test with anesthesia, and tear-film breakup time.
Results:
Corneal sensation was significantly reduced from preoperative levels through 6 months in the narrow-hinge group and through 3 months in the wider-hinge group (P< or =.002). The mean corneal sensation was greater in corneas with a wider hinge flap than in those with a narrow hinge flap at all postoperative examinations; the difference was significant at 1 and 3 months (P< or =.002). The loss of sensation was greatest at 1 week and improved at all subsequent examinations. Overall, dry-eye signs and symptoms were greatest immediately postoperatively and improved at subsequent intervals.
Conclusions:
Corneal sensation and dry-eye signs and symptoms improved at all intervals between 1 week and 6 months. The loss of corneal sensation and presence of dry-eye syndrome were greater in eyes with a narrow hinge flap than in eyes with a wider hinge flap.
