Supra-capsular phaco a good option for refractive cataract surgery

KOLOA, Hawaii — Supra-capsular phacoemulsification is particularly suited to refractive cataract surgery which is often done softer nuclei, said one surgeon.

Speaking here Richard L. Lindstrom, MD, Hawaiian Eye 2007 meeting co-program chair and OSN Chief Medical Editor, said that the supra-capsular phacoemulsification technique is safe and fast, particularly for softer lenses. In addition, because the nucleus is brought anteriorly, above the iris plane, this technique is well suited for floppy iris syndrome, as the nucleus will hold the iris down during phacoemulsification. In addition, because the phacoemulsification is performed more anterior, there is greater distance from the posterior capsule, which may translate to an increased safety margin for the prevention of capsular breaks and vitreous prolapse, he said.

The technique involves performing a sufficiently large capsulorrhexis, at least 5 mm in diameter, followed by significant hydrodissection. Dr. Lindstrom performs the hydrodissection in a controlled, pulsatile manner in order to prolapse the nucleus out of the capsular bag. Once the nucleus is partially tilted out of the capsular bag, the nucleus can be further prolapsed by injecting viscoelastic behind it.

The 30° phaco tip is place bevel down to direct the ultrasound energy into the cataract and away from the corneal endothelium. Dr. Lindstrom employs higher vacuum for this technique, using 300 mm Hg to 400 mm Hg for a venturi pump and 400 mm Hg to 600 mm Hg for a peristaltic pump. Although a moderate to higher flow rate is used for the infusion, a flow restrictor is used on the outflow tubing to maintain a stable anterior chamber.

At the end of the case, hydration of both the primary clear corneal incision as well as the paracentesis is performed in order to ensure a watertight eye. Standard postoperative topical mediations include a fluoroquinolone, a corticosteroid, and a nonsteroidal anti-inflammatory drug, he noted.

In a study performed by Dr. Lindstrom and colleagues, he noted a 4% endothelial cell loss rate for the routine cataracts, which have preoperative visual acuities of 20/30 to 20/70. This technique is not recommended for the dense brunescent cataracts, where an endocapsular approach would likely enable greater corneal endothelial cell protection. For the majority of refractive cataract patients, the ease of the supra-capsular technique and the increased safety margin from being away from the posterior capsule makes this an excellent technique that most surgeons can learn and implement.