Category: Health And Fitness - Child Health

Managing Lasik Keratome Complications

Author: SamMelki

State of the art LASIK technology avoids the following problems during
quality laser eye surgery


The Sliding Suction Ring

Application of adequate suction is essential
for intraocular pressure
upsurge and dissection of good quality corneal
flaps. On occasion, the suction ring slides prior to the buildup of
adequate vacuum and the flap is decentered from the pupillary axis.
This is reported to happen more frequently with the Hansatome
microkeratome due to a slower rise in vacuum. Applying equal downwards
pressure on the ring through its handle and at the base knob for about
3 seconds prior to initiating vacuum has minimized this problem.

On occasion, the initial vacuum results in a
decentered ring with a large slant requiring the surgeon to release the
vacuum to reposition the ring. It is not uncommon to see the ring
sliding back in the conjunctival groove created by the initial suction.
Decentering the ring in the opposite direction prior to activating
suction may achieve good centration as the vacuum level may be high
enough by the time the ring slides close to the center to prevent
further slide towards the initial groove.

Another approach is to change the ring size (e.g. from 8.5 to 9.5 mm),
hence avoiding the chemotic conjunctiva. Some surgeons advocate
applying  Vasocon-A (Alcon Laboratories, Fort Worth TX) allowing a
decrease in conjunctival swelling prior to reattempting the procedure
30 minutes later. If this does not resolve the conjunctival chemosis,
further difficulties might be encountered and it is best delaying the
surgery for another day

The Mid-Cut Jam

The suction ring has fit well, the keratome slides easily in place and
the cut is proceeding smoothly until….it stops half-way and does not
respond to either forward or backwards pedal commands. This unpleasant
situation can occur secondary to a mechanical or electrical failure of
the keratome. The main goal of the surgeon in that situation is to
protect the flap and the bed from the keratome blade. Although resuming
forward movement may result in an uneven cut, we have not encountered
this in our experience.
A quick check of electrical wiring may reveal a loose connection
especially at the connection with the keratome motor. Every keratome
should be handled differently in this situation and the surgeon should
inquire about the best approach to handle such a situation. For the
Hansatome, if no movement can be initiated, careful release of suction
and sliding the keratome-suction ring as one unit backwards will ensure
that the flap is not incarcerated under the blade. The keratome head
cannot be reversed along the track manually. On the other hand, with
the Automated Corneal Shaper (ACS), releasing suction might trap the
flap under the footplate. It is therefore preferable to disassemble the
keratome head from its base without releasing suction.