Hi Susanne In the first step of the LASIK procedure, a ‘flap’ is created using a femtosecond laser (or, in the past, a special blade called a microkeratome). During this step, the laser is ‘connected’/docked to the eye with a ring-like device that grips the white part of your eye.
You can watch an animation here:
There are many small blood vessels on this part of the eye, and sometimes the suction pressure providing the grip may cause some of the blood vessels to leak some blood, causing red patches after the LASIK.
We call this a subconjunctival haemorrhage, or SCH. The risk is somewhat higher if, during the procedure the docking process has to be repeated. This is occasionally necessary if during the first attempt, the eye rolls or for whatever other reason the ring is determined not to be well centered.
There isn’t any guaranteed way to prevent this from happening. Although it can look alarming if large, there is no effect on the final outcome and vision will be unaffected by this redness.
Of course, if a flapless procedure like PRK/TransPRK/epiLASIK is chosen, there will be no risk of SCH, but on the other hand the usual cons of PRK type procedures such as delayed visual recovery need to be considered.
Depending on the size of the red patch, cases of SCH can take anywhere from several days to several weeks to fully resolve. During this time, there is no specific method to hasten recovery, but do use the usual post LASIK eyedrops like antibotics and artificial tears as advised by your doctor.
