Ophthalmic viscosurgical device provides procedural control, endothelial cell protection

Aug 15, 2010

Because of the versatility that 2.3% sodium hyaluronate provides, the author has used the ophthalmic viscosurgical device in every case for the past 5 years.

Charlotte, NC-Because of the versatility that 2.3% sodium hyaluronate (Healon5, Abbott Medical Optics [AMO]) provides, I have used the ophthalmic viscosurgical device (OVD) in every case for the past 5 years. The product is unique in that it allows the surgeon to control the behavior of the OVD by adjusting aspiration flow rates. At low flow rates, it acts like a cohesive agent to maintain the anterior chamber; at high flow rates, it acts like a dispersive agent to protect endothelial cells during phacoemulsification.

Its cohesive properties allow the OVD to create space, displace tissue, pressurize the anterior chamber, and provide clear visibility, whereas the product's dispersive properties allow it to remain in the anterior chamber during phacoemulsification, protecting the endothelium.

It's been my experience that the agent stays in the anterior chamber better than any other OVD, and it has easy removal. I have never had a pressure spike after using 2.3% sodium hyaluronate. When implanting toric or multifocal IOLs, I use both 1% sodium hyaluronate (Healon, AMO) and 2.3% sodium hyaluronate. I use a soft-shell technique where I place 1% sodium hyaluronate centrally on top of the anterior capsule to ensure a large capsulorhexis. In cases where good visibility exists and a standard implant is in use, 2.3% sodium hyaluronate is used alone, which is what I prefer.

For most cases, I use a temporal approach with a 3-mm incision at the vascularized limbus. I use a guarded 350-µm depth blade to create the initial groove. Then, I use a crescent blade and dissect 2 mm into the clear cornea. This approach is astigmatically neutral.

After dissection with the crescent blade, I do a stab incision about 90° from the temporal approach, either inferiorly on the left eye or superiorly on the right eye.

I fill the anterior chamber three-quarters full with 2.3% sodium hyaluronate. I then enter the anterior chamber with a 2.75-mm keratome and begin the capsulorhexis with a bent cystotome needle and finish the capsulorhexis with a Utrata forceps. After that, I hydrodissect and hydrodelineate with balanced salt solution. I rotate the nucleus with a Sinskey hook, and with a cyclodialysis spatula, I do a conquer-and-divide technique with the phacoemulsification unit and utilize a cracking forceps when indicated. Phacoemulsification is performed at the iris plane of the four quadrants of the nucleus.

With 2.3% sodium hyaluronate, I do not have to refill the anterior chamber or the mid-iris plane with additional viscoelastic because the OVD stays in place, protecting the endothelium. After removal of the nucleus and cortical clean-up, I use 2.3% sodium hyaluronate to load the implant and then fill the capsular bag. I typically use a one-piece acrylic IOL, but I have also used a three-piece IOL.

I find that 2.3% sodium hyaluronate provides better control during insertion than other OVDs. It keeps the capsular bag stable and allows gentle opening of non-acrylic IOLs. It allows for easy positioning of the implant and gentle manipulation of the implant in the capsular bag. Silicone and acrylic implants stay suspended and allow easy removal of 2.3% sodium hyaluronate in the posterior portion of the bag, followed by final positioning of the IOL.

Additionally, 2.3% sodium hyaluronate offsets positive pressure and minimizes the risk of developing a shallow anterior chamber. In a study conducted by Holzer and colleagues, 2.3% sodium hyaluronate had the lowest endothelial cell loss rate (–6.2%) compared with 1.4% sodium hyaluronate (Healon GV, AMO) (–10.9%), 4% sodium chondroitin sulfate–3% sodium hyaluronate (Viscoat, Alcon Laboratories) (–15.4%), and 2% hydroxypropyl methylcellulose (OcuCoat, Bausch + Lomb) (–16.7%).1

Also, 2.3% sodium hyaluronate is especially helpful when operating on patients who have taken tamsulosin (Flomax, Boehringer Ingelheim). Even one dose of tamsulosin can result in poor dilation and pupillary constriction and an intraoperative floppy iris syndrome. The OVD offers maximum visibility by gently opening the pupil and providing 1 to 2 mm of additional exposure. This is key to successful surgery. Whether performing phaco-chop or divide-and-conquer, 2.3% sodium hyaluronate gives surgeons an edge with maximum visibility.