Today, the use of an ophthalmic viscosurgical device (OVD) is a standard practice in ophthalmology procedures, including cataract, glaucoma, corneal, vitreoretinal, and even traumatic surgeries.1,2 OVDs are, however, probably the most underestimated tool in anterior segment surgery.
In the recent past, the only commercially available OVD was Healon (Advanced Medical Optics, Inc., Santa Ana, California). Currently, there are now various OVDs available, all with different physical properties and uses. To state that all OVDs are alike is akin to claiming that it is possible to perform phacoemulsification with just one instrument—and we all know that this is not possible.
I was recently asked to assess the performance and handling of newer versus traditional OVDs as part of a larger, 21-center European study.3 In this article, I will review my overall impression of and the importance in selecting the proper OVD.
The importance of OVDs should not be discounted. If one were to attempt phaco surgery without an OVD, implanting the IOL into the anterior segment with air only, the value of OVDs would quickly be realized. This surgical tool has made IOL implantation much easier, and newer formulations offer even more specialized functions. One example is Healon5, which is the only OVD that can be appropriate for every surgical situation.
For me, it is interesting to learn why surgeons with different phacoemulsification approaches choose a particular OVD. Many choose an OVD according to the way it performs throughout the steps of cataract surgery—creation of the capsulorrhexis, IOL implantation, phacoemulsification, and OVD removal. Therefore, the surgeon's individual phaco technique and preferences may largely influence his selection.
Personally, I like Healon5 because it provides me with optimum control during every step of the procedure—although its use meant changing my surgical technique in certain steps, including my fluidics settings. I use a low phaco setting, a flow rate of 24 cc/min or less, and aspiration rates between 100 and 120 mm Hg. With these settings, I can achieve a good result within the limits and confinements of the capsular bag.
During a routine phaco procedure, I typically use 40 to 50 cc of fluid, which can only be managed by limiting the phaco process to the capsular bag with no turbulence in the anterior chamber. Using Healon5 at low-flow and low-vacuum settings is ideal. For those surgeons who do not want the OVD in the anterior chamber during phaco, Healon GV is a good alternative because it leaves the eye immediately when you start the phaco process.
IS NEWER BETTER?
I have become a low-flow, low-vacuum visco phaco surgeon. Therefore, I almost exclusively use a viscoadaptive OVD, such as Healon5.
The difference between Healon and Healon5 is that the latter has a higher molecular concentration. Interestingly, when it comes to OVDs, it does not always take a new substance to largely improve surgical performance. Sometimes changes in the concentration or chain length, or a combination of these, may result in an improved product. If newer OVDs incorporate new physical properties that will further aid cataract surgery, then in my opinion, newer is better.
Manfred R. Tetz, MD, is the Director of the Eye Center-Spreebogen, Berlin, and Scientific Director of the Berlin Eye Research Institute. Professor Tetz states that he has no financial interest in the companies or products mentioned. He has, however, been a consultant to Advanced Medical Optics, Inc., and performed studies with various OVD manufacturers. Professor Tetz is a member of the CRST Europe Editorial Board. He may be reached at tel: +49 30 398098 0; e-mail: firstname.lastname@example.org.