There are three main steps to master before you can successfully perform femtosecond laser assisted cataract surgery, says Dr. Michael Knorz, professor of ophthalmology at the University of Heidelberg in Mannheim, Germany.
Once mastered, surgery proceeds just as standard phacoemulsification, Dr. Knorz told attendees at the 2013 Congress of the European Society of Cataract and Refractive Surgeons. “It’s just easier because the nucleus is already pre-fragmented.”
The first step to master is docking the eye to the laser. This step does require practice, especially if you have not performed femtosecond laser LASIK surgery. He says you must get a good central docking without excessive tilt of the eye. Docking is achieved differently, depending on the machine used. With the Alcon LenSx, a suction piece is lowered down on the eye directly. However with the Victus, Catalys, and LensAR systems, a suction ring is placed on the eye first and the laser cone is lowered onto the suction ring.
Dr. Knorz notes that you may have to rotate the patient’s head to keep their nose out of the way. If a suction break occurs during the laser portion of the procedure, he advises against re-docking. Instead perform a manual procedure.
The second step to master is entering the anterior chamber and checking the capsulorhexis. “The capsulorhexis must be complete,” he said. “If it is not, it could cause rupture of anterior capsule.”
To verify, inject viscoelastic and use the phaco tip to check that the capsulorhexis is complete. If there are any tags, remove them manually. He uses a blunt spatula to open the side-port incision first, then he injects viscoelastic to avoid anterior chamber shallowing.
It’s important to check the completeness of the capsulorhexis because undetected tags may lead to an anterior capsule tear. He uses a phaco tip to check and aspirate the anterior capsule after checking for completeness. Though tags are rare with today’s lasers, should they be present, he removes the phaco tip and uses capsulorhexis forceps to complete the capsulorhexis.
Lastly, you will need to modify your hydrodissection technique. The laser creates air bubbles in the capsular bag that may increase pressure in the bag, especially if you have used a small capsulorhexis. Hydrodissection should be gentle and slow with low volume to avoid capsular blow-out syndrome.
He says you may also split the nucleus with a chopper, splitter or hook to allow the trapped air to escape before hydrodissection. After checking to ensure the capsulorhexis is complete, he aspirates the anterior capsule and introduces the hydrodissection cannula into the anterior chamber using his second hand. He then proceeds with careful hydrodissection while aspirating with the phaco tip simultaneously to avoid an increase in pressure.