MANAGING CATARACTS

Femtosecond laser-assisted cataract surgery can allow surgeons to deal with challenging cataract cases that would be difficult or near impossible to treat with conventional surgery, Soon-Phaik Chee MD told a session of the World Ophthalmology Congress in Tokyo.

“Femtosecond laser capsulotomy and nucleus fragmentation has made the management of complicated cataracts easier for the surgeon and safer for the patient,” said Dr Chee, senior consultant, head, Uveitis and Cataract Subspecialty Service, Singapore National Eye Centre.

She presented a selection of cases from her own practice where the femtosecond laser had proved useful. Her first example was brunescent cataract. “These brunescent cataracts are particularly difficult to treat without compromising the cornea, especially if the anterior chamber is shallow. I routinely do these with the femtosecond laser.”

She said she typically started by performing a 5.0mm capsulotomy with the laser. She uses the Victus platform (Bausch + Lomb), which she noted allows her to make deep cuts close to the posterior capsule, making segmentation easier. She makes up to eight segments depending on the density of the nucleus. She advocates using dye for improved visualisation for those beginning femtosecond laser-assisted cataract surgery, along with a dispersive OVD to protect the cornea. She stressed the importance of having a good phaco machine with high vacuum settings to help hold on to fragments. She also said one should only use minimal ultrasound energy to prevent harming the corneal endothelium.

Dock carefully

Intumescent cataracts with a white-on-black nucleus are another challenging case where the femtosecond laser can be helpful, she noted. “It is very important in these cases to dock carefully. You want to be meticulous. You need a capsule that is evenly docked, you don't want one that is slanted, or you may have capsulotomy that runs away. You might cut one portion of capsule before the other, which could result in rip of anterior capsule.”

In cases involving intumescent cataracts she also routinely uses IV mannitol to shrink the nucleus before applying the femtosecond laser, another technique for reducing the risk of an anterior capsule rip.

“Staining the capsule is also very useful in these cases. It helps keep the capsule visualised as you chop this very dense nucleus. Even with these white nucleus cataracts I routinely apply the femtosecond laser to segment these.”

Other cases where the femtosecond laser could provide a decisive benefit include Labrador corneal dystrophy, soft posterior polar cataracts, small uveitic cataracts and subluxated cataracts, she told the assembly.

Soon-Phaik Chee:
Chee.soon.phaik@snec.com.sg