Diamond knives, while already frequently used in
ophthalmology, continue to become more popular. As we continue to improve our surgical techniques, diamond knives offer many advantages over traditional blades; Scanning electron microscopy has shown that diamond knife incisions induce less disruption to the corneal epithelium and stroma (Galbavy EJ. Use of Diamond Knives in Ocular Surgery. Ophthalmic Surg. 1984 Mar;15(3):203-5). Many physicians also feel their incisions created with diamond knives heal better. There are disadvantages as well–the blades cut through tissue so effortlessly that physicians lose the tactile feedback of a traditional blade. Additionally, diamond blades are expensive and require high levels of care to minimize dulling of the blade. If the blades are handled appropriately, however, their pre-surgery cost compares favorably. While used primarily in
cataract surgery, more shapes and styles are being constructed in diamond blades to increase the range of applications.
The most frequent procedure where physicians feel diamond blades reign superior are limbal relaxing incisions. These knives are available in pre-set as well as adjustable depths. An exciting LRI blade is the Donnenfeld LRI Knife (Accutome): With a short titanium handle and angled footblade, this device has been developed so that LRIs can be performed post-cataract surgery at the slit lamp.
Corneal trephination is another area in which diamond knives may improve surgical technique. The Alfonso Diamond Knife (Rumex International) allows the cornea to be cut with a simple sawing motion, minimizing traditional crush injury imparted by corneoscleral scissors. The distal end of the knife is blunt, to avoid any injury to the underlying iris and lens.
Though not usually refractive surgery, retinal surgery may also benefit from diamond blade technology. The MVR diamond knife, available from Diamatrix, allows for consistently created sclerotomies without placing unnecessary pressure on the external globe.
There are multiple other uses for these blades. Straight, angled, and crescent diamond blades are available facilitate create clear-corneal and scleral tunnel incisions for cataract and glaucoma surgeries.
In summary, a multitude of diamond blades are available for all forms of ophthalmic surgery, each of these forged with the goal of enhancing ophthalmologists’ surgical performance. In my practice, I have had excellent results with diamond blades where I use them primarily for cataract surgery and limbal relaxing incisions. Unfortunately, the blades have had to be sent back for repair twice following inappropriate handling in the autoclave by surgical staff. However, the incisions are extremely consistent and post-operative patient comfort is outstanding.
That said, metal blades continue to improve and should not be completely disregarded. An excellent example includes the Atomic Edge and Xstar safety blades (BD Surgical): Encased in retractable blade covers, these instruments provide excellent incisions due to their near-diamond like quality.
Please see the products listed below, or check out our Diamond Knives section for more information.