Flap Hinges - which type is best FAQ
Please select your question from the following list of FAQs:
LASIK is perfomed by creating a cornea flap. Are there choices in the orientation of the flap?
There are multiple devices (called microkeratomes) to create the LASIK flap. For the first 25 years, flaps have always been created horizontally, with the hinge on the nasal side. In this way, the flap can be reflected over to allow the laser to treat the underlying cornea.
More recently, there are new microkeratomes that create a flap with a superior hinge. There has been debate as to whether superior hinges improve the results of LASIK
Why would superior hinges be better?
The theory is that with a superior hinge, gravity can help to make the flap stick better. As well, the blinking of the eye is in the same orientation as the flap. The hope is that this would reduce the risk for flap striae/wrinkles.
Why not compare the visual results of flaps with different orientations
Steven Updegraff, MD performed a study on 100 patients where he performed a superior hinged flap in one eye and an inferior hinged flap in the other eye. He found no difference between the two techniques as far as visual results and need for retreatment. As well, he did note two patients with mild striae - these were both in eyes with superior hinges.
Conclusions
There are probably no differences in visual results between patients who have flaps with nasal hinges versus superior hinges. Dr. Eric Donenfeld has performed research that suggests that superior flaps do lead to more dry eye symptoms than nasal hinge flaps Updated July 2002