Bimanual phacoemulsification with the Millennium system yields good results
Fluidics, stability and small incision size make bimanual microincision phaco a better choice than coaxial phaco, surgeon says.
I. Howard Fine
Bimanual microincision phacoemulsification at this time is similar to coaxial phaco in the mid-1980s. Critics said there was no reason to do phaco through a 3-mm incision when the incision had to be enlarged to 7 mm for IOL implantation.
We countered that phaco was a better operation than extracapsular extraction even though we had to enlarge the incision. The same applies to bimanual microincision phacoemulsification today.We performed bimanual microincision phacoemulsification on 39 cataracts utilizing phaco burst mode on the Bausch & Lomb Millennium phacoemulsification system. We used a linear burst interval up to 1.2 seconds controlled in foot position three with a burst width of 100 milliseconds. The Millennium phacoemulsification system is unique in that it is capable of independent linear control of both phaco power and vacuum level (Figure 1).
The results of the 39 eyes are reported on in Figure 2. These results compare favorably with what we have achieved previously with coaxial phacoemulsification and pulse mode; however, there was no statistically significant difference. We achieved 100% clear corneas and 95% uncorrected visual acuity of 20/40 or better in the 2- to 24-hour postoperative period. The average grade of the cataract was 2+.
Bimanual vs. coaxial
Image: Fine IH
We believe that bimanual microincision phacoemulsification is a better operation than coaxial phacoemulsification because of the improvement in fluidics, the stability of the anterior and posterior chamber and the smaller incision size. With bimanual microincision phacoemulsification, all of the fluid enters the eye from one side and exits through the other, so there are no competing currents around the phacoemulsification tip. We can use the incoming stream of fluid to manipulate tissue position and therefore facilitate mobilization of cataract material. The bimanual system is closer to an ideal system than coaxial phacoemulsification; an ideal system would be one in which the system was completely closed. We have experienced no thermal injury to the incisions. We routinely separate our incisions by 60° to 90°. Rather than enlarging one of the microincisions, which become somewhat distorted as a result of manipulation of the instruments through them, we make a 2.5-mm incision between them for the implantation of the IOL.
We believe that bimanual microincision phacoemulsification will gain in popularity, ultimately replacing coaxial phacoemulsification. As lenses capable of being inserted through increasingly smaller incisions become available, we will continue to make an implantation incision between the two side-port incisions until we achieve the ability to implant a lens through an unenlarged microincision utilized for cataract removal.
For Your Information:
- I. Howard Fine, MD, is a clinical professor of ophthalmology at the Casey Eye Institute at Oregon Health & Science University in Portland and in clinical practice with Drs. Fine, Hoffman & Packer, LLC, at 1550 Oak St., Suite 5, Eugene, OR, 97401; 541-687-2110; fax: 541-484-3883; e-mail: email@example.com; Web site: www.finemd.com. Dr. Fine is a paid consultant for Bausch & Lomb.
- Bausch & Lomb can be reached at 1400 N. Goodman St., Rochester, NY 14609; 585-338-5212; fax: 585-338-0898; Web site: www.bausch.com.