Advantages of bevel-down technique

Le résumé fourni par la source

The study by Kim et al.1 comparing bevel-down phacoemulsification and bevel-up phacoemulsification is seriously flawed because of the use of bevel-down sculpting. Sculpting is essentially a shaving technique and to do bevel-down shaving is the equivalent of using a snow plow with the plow attached to the vehicle backward. Bevel-down phacoemulsification has several advantages for chopping techniques. All the energy is directed toward the cataract; none is directed toward the corneal endothelium or trabecular meshwork. It is easy to aspirate the epinucleus exposed by the capsulorhexis with the tip bevel down. One can achieve a vacuum almost immediately on contact of the bevel-down 30-degree tip with the endonuclear surface and can therefore use vacuum with very little ultrasound energy to embed the phaco tip; in contrast, the bevel-up configuration requires considerable energy to get the entire bevel into the endonucleus before occlusion and vacuum can be achieved. Finally, with a bevel-down configuration, segments can be safely mobilized from the endolenticular space at the level of the capsulorhexis equidistant from the posterior capsule and the corneal endothelium by occluding the tip on top of the segment.2 Although I do not have recent objective quantitative data as the authors do (percentage of endothelial cell loss), I can state that I have been using a bevel-down tip since chopping was first described by Nagahara in 1993.A Corneal haze on postoperative day 1, even in 4-plus nuclear density cataracts, has been rare in my experience.3

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.