Improving outcomes in challenging cases
The benefits of using the laser to facilitate surgery in a variety of complex situations was highlighted by Dr Ahmed Assaf, Ain Shams University, Cairo, Egypt. Dr Assaf presented cases of hard cataract, which he said is a common scenario that he sees. In these cases, he uses the laser to segment the nucleus into quadrants and then to soften the lens.
His approach is based on the results of a study he conducted that compared ultrasound energy use in FLACS and conventional phacoemulsification cases using a quick chop technique. With eyes stratified by nuclear density using the LOCS III system, Dr Assaf found that for eyes with NS 3-4 cataracts, overall ultrasound energy use was significantly less when performing FLACS.
He found no difference in overall ultrasound energy use between the two surgical groups in eyes with NS 5-6 cataracts. Analysing data for the NS 5-6 cataracts by phase of the procedure, Dr Assaf also found no significant difference between FLACS and conventional phaco in ultrasound energy used for nuclear disassembly. However, ultrasound energy use during quadrant removal was significantly lower in the FLACS group.
“This study shows that laser segmentation in eyes with very dense cataracts does not increase efficiency as we thought it would, probably because the laser does not treat the most posterior area of these lenses. However, there is a benefit for softening these cataracts with the laser to increase efficiency during quadrant removal,” Dr Assaf said.
Other challenging cases where Dr Assaf said he finds the laser especially helpful include eyes with weak zonules and subluxated lenses. He said he also uses the laser in eyes with white cataracts, but for capsulotomy only.
In these cases, Dr Assaf reduces the incision depth from 600 to 400 μm, sets horizontal spot spacing to 10 microns, and increases his vertical spot spacing to 16 μm.
“Using the laser for capsulotomy only can convert a white cataract case from challenging to routine,” he said.
Dr Assaf added that sometimes he will find a tongue at the capsulotomy edge when using the laser for capsulotomy in eyes with white cataract, but he has not found it to be of any clinical significance, as it has not affected the course of the surgery.
Dr Assaf said he also finds the laser helpful for performing the capsulotomy when there is an anterior fibrous plaque on the capsule. In this situation, he increases the incision depth to 800 μm to assure the cut penetrates the plaque.
“Some manual cutting may still be needed, but the laser treatment greatly enables completion of the capsulotomy,” he explained. He also appreciates having the laser to make the capsulotomy in eyes with phacomorphic glaucoma where a shallow anterior chamber makes manual capsulorhexis challenging.