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Up Front | May 2005

The Cataract Incision

Surgeons share their advice on its creation, architecture, and management.

Although discussed less frequently at meetings than phaco techniques and technology, the cataract incision is integral to a successful procedure. Cataract & Refractive Surgery Today asked several surgeons for their tips.

I use a diamond scalpel for cataract surgery incisions. I prefer a trapezoidal blade, specifically the Fine Stealth Triamond blade (Mastel Precision, Inc., Rapid City, SD), which I can use freehand to create an incision of any size, from 0.3mm up. A marker that scores the epithelium facilitates the creation of accurately sized incisions to within 0.1mm (Figure 1).

I make my surgical incision in the same location, except in special circumstances such as zonulolysis. I sit beside the patient so that visualization is optimal and my angle of attack is the same regardless of the patient's brow configuration. The angle of attack must be greater than 17º as Jack Singer, MD, taught us.1 I perform the paracentesis 90º away from my main incision and strive to make the paracentesis 0.5mm wide and at least 0.75 to 1.0mm long in order to avoid a leaky chamber. I prefer the single-plane incision as originally described by Dr. Fine.2

I only make a groove when combining the cataract incision with a limbal relaxing incision for greater than 2.00D of against-the-rule astigmatism. I expect approximately 0.25D of with-the-rule astigmatism to result from my temporal incision and take this into account when planning the need for a simultaneous, peripheral astigmatic keratotomy. I aim for a true clear corneal entry, just inside the vessels, and prefer a 1.75- to 2-mm long tunnel. The incision should remain under 3mm wide if it is to be sutureless. Consistent pressurization of the anterior chamber is important when creating the incision. If the eye is too firm, a shorter tunnel than desired will result. A globe that is too soft will promote an undesirably long tunnel. Instilling viscoelastic through the sideport incision without allowing too much aqueous to escape will achieve a greater-than-physiologic pressure without overfilling the anterior chamber. After creating the main incision, I use a dispersive ophthalmic viscoelastic device (OVD) and then add a cohesive OVD underneath to create a soft shell as described by Steve Arshinoff, MD, of Toronto.3 The goal is to produce a straight incision externally at the epithelium and internally at the level of Descemet's membrane. To do so with the Fine Stealth Triamond blade, it is important to keep the keratome level and parallel to the iris once Descemet's is breached and while the knife is moving laterally.

I fixate the globe with a Fine-Thornton ring, which allows me to move the eye and the blade as the incision is created. This technique yields exquisite control. It is important not to touch the roof of the incision with the forceps and to avoid lifting the phaco needle, which may compress the sleeve against the roof of the incision and restrict flow. I am always careful to establish flow within the chamber before initiating ultrasound to avoid any possibility of wound burn. One of the many advantages of a discontinuous phaco strategy (burst or pulse mode) is that it avoids thermal damage.

A meticulously created and managed incision will almost always seal as soon as the internal valve is cleared of foreign material. I like to irrigate the opening to be sure no tiny lenticular fragment or OVD is still present. I perform minimal stromal hydration to establish secure closure. After irrigating the main incision, I control IOP through the paracentesis by first overfilling the anterior chamber to ensure that the incision is secure and then burping the paracentesis until the pressure is at a physiologic range by palpation. I then use a Weck-cel sponge (Medtronic Xomed Ophthalmics, Inc., Minneapolis, MN) to see a dry gutter at the main incision at a normal pressure. Usually the hardest incision to seal securely is the paracentesis, which will sometimes ooze slightly when the pressure is high. I perform stromal hydration of the paracentesis as well.

I have a low threshold for adding a suture. If an incision does not seal on the first try, I will allow 1 to 2 minutes for any “fish-mouthing” of the internal incision to resolve if the incision is anatomically correct. Sometimes, raising the lid speculum from the globe will resolve this change in configuration and result in a secure seal with the next attempt at hydrating or irrigating the sides of the incision. I place a suture if I see that Descemet's is out of place, I observe that the anatomy of the incision is suboptimal, or fish-mouthing continues for more than 2 minutes after the resolution of any pressure on the globe. I prefer a 10–0 Biosorb suture (Alcon Laboratories, Inc., Fort Worth, TX), which, although wiry like Prolene (Ethicon Inc., Somerville, NJ), is absorbable over a period of 1 to 2 months. A single radial suture is generally optimal. I never leave a pediatric cataract incision greater than 1mm unsutured. I will also place a suture in the presence of a vigorous filtering bleb for fear that the IOP may be low enough to compromise the internal valve closure during the early postoperative period.


To achieve a completely astigmatically neutral, self-sealing cataract incision, the surgeon should place the incision on the clear cornea, anterior to the vascular arcades, either in the temporal region (where the pulling and gaping effect of the rectus muscles is the least) or in the oblique, temporal location farthest from the optical center of the eye.4 The incision should be constructed in a plane parallel to the iris. Surgeons who routinely work on the cornea know that incisions there are unforgiving: they need to be sized appropriately, or they will be stretched or torn, inducing unwanted astigmatism and poor healing.

The ideal incision follows the arc of the cornea and is rectangular, with a width-to-length ratio of approximately 3:2. Surgeons should correct astigmatism greater than 0.50D with a two-plane, vertical incision of 90% depth followed by parallel entry in the horizontal plane.5,6 I always place a clear corneal incision on the steep meridian to induce a predictable, controlled amount of flattening7,8 (Figure 2). If more than 1.50D of astigmatism is present, an additional arcuate vertical incision on the opposite meridian will help correct it.

Although diamonds are a surgeon's best friend, they are expensive and fragile, and these blades require careful handling. Using semiconductor technology from the computer age, the affordable, disposable BD Atomic Edge Blade (BD Ophthalmic Systems, Franklin Lakes, NJ) creates a diamond-like incision. I mark the incision with the Arcuate A/K Marker from Rhein Medical Inc. (Tampa, FL). For a clever way to automatically construct arcuate incisions, I recommend the Terry/Schanzlin Astigmatome (OASIS Medical, Inc., Glendora, CA). Nomograms may be downloaded from http://www.bd.com/ophthalmology, http://www.oasismedical.com, and http://www.eyelasercenter.com/physicianresource.htm.


Initially, I was most impressed when I was shown several electron-microscopic views of metal blades and the black diamond knives from Accutome, Inc. (Malvern, PA). It was obvious that, after several applications, the diamond blades remained sharp, without wearing of the edges, whereas the metal blades showed early signs of wear and change. These diamond blades allow me to create a precise, self-sealing corneal incision case after case. After many thousands of surgeries, I am also convinced that autoclaving does not affect the sharpness of these knives. My ASC administrator and I have reviewed our data to assess the cost effectiveness of the Accutome black diamond knives we are using as compared with disposable blades, and we are convinced that the diamond blades are the best choice.

My primary reason for committing to these knives is the reproducibility of the incisions I create. Whether the eye is firm, is deep-set, or has undergone previous surgery, the incision is perfect in each and every case. Glare and incisional hydration are not factors. These blades create an accurate linear incision, which allows me to focus on the surgery and not my instrumentation.


I make two incisions whether performing standard coaxial phacoemulsification or using the Aqualase Liquefaction Device (Alcon Laboratories, Inc.). The cataract incision is temporal and located at the limbus, and it does not involve the conjunctiva. I place the sideport incision approximately 90º from the cataract incision at the limbus, also without involving the conjunctiva. My sideport incision is tapered such that it is 1mm wide at the epithelium (Figure 3A) but 0.8mm long at the endothelium. My cataract incision is 3.2mm if I am using the Aqualase Liquefaction Device. For ultrasound, I use a 2.2-mm incision when employing a 0.9-mm flared microtip with an ultraflow sleeve. With a standard 1.1-mm phaco tip and a high-infusion sleeve, the incision is 3.2mm.

I create the cataract incision with a stainless steel, clear-cut, high-performance, dual-beveled, angled keratome (Figure 3B). For the sideport incision, I rely on a 1-mm, angled, sideport blade. For all cataract incisions, I plan a corneal intrastromal tunnel of between 1 and 2mm in length. I strive to avoid a short entry that is perpendicular to the epithelium. Instead, the entry should be at an acute angle.

The incision can tear, stretch, or burn if the surgeon exerts enough pressure against and/or sufficiently manipulates the tissue. For that reason, I keep instrumentation at the center of the incision to allow the proper inflow of irrigation and permit adequate incisional outflow. I test all incisions for leakage by raising IOP to a normal tension and pressing on the globe in a dry field. If in doubt, I place a single 10–0 radial suture.


Constructing the incision is only one factor in successful clear corneal cataract surgery. For example, I favor fourth-generation fluoroquinolones as pre-, intra-, and postoperative antibiotics. Additionally, it is important to prepare the surgical field, for which I use 5% povidone-iodine (Betadine; The Purdue Frederick Company, Stamford, CT) as a scrub. I evert the lashes with steristrips, drape over the meibomian orifices, and put a wick in the lateral canthus angle to allow for continuous drainage. I always operate at the temporal corneal periphery and use limbal relaxing incisions rather than incisions in the steep axis to address astigmatism. The corneal periphery, temporally, allows for the neutralization of the forces of gravity and blinking eyelids.

I fill the anterior chamber through a sideport incision with viscoelastic while expressing aqueous in order to create a stable, firm eye that will not become unpredictably distorted as I make the incision. The architecture of the cataract incision is a single plane, in the plane of the cornea. I can include the corneal vascular arcade as long as I am anterior to the conjunctiva. I direct the knife in the plane of the cornea for 2mm and then enter Descemet's. The incision's width is no larger than 3.5mm. I like trapezoidal knives, which allow me to enlarge the incision without sacrificing architecture as side-cutting knives do. I strongly prefer the 3-D Blade (Rhein Medical Inc.).

Surgical technique is an important part of the process. I never grasp the superior lip of the incision with a forceps, because abrading the epithelium will eliminate the fluid barrier that allows for vacuum sealing as a result of endothelial pumping. I use power modulations to minimize thermal injury to the incision. Additionally, I feel that IOL implantation should not involve aggressive stretching of the incision, the eye should be stabilized with a fixation ring, and injectors are far superior to forceps for IOL insertion. Finally, I always ensure the incision's closure with stromal hydration and perform fluorescein testing to be certain there is no leakage.

Lisa Brothers Arbisser, MD, is in private practice in Davenport, Iowa. She has received research grants and occasionally honoraria and travel support from Advanced Medical Optics, Inc., and Alcon Laboratories, Inc. Dr. Arbisser may be reached at (563) 323-8888; drlisa@arbisser.com.
I. Howard Fine, MD, is Clinical Professor of Ophthalmology at the Casey Eye Institute, Oregon Health & Science University, and he is in private practice at Drs. Fine, Hoffman, & Packer in Eugene, Oregon. Dr. Fine receives research and travel support from Alcon Laboratories, Inc., but he states that he holds no financial interest in the products or other companies mentioned herein. Dr. Fine may be reached at (541) 687-2110; hfine@finemd.com.
Brett W. Katzen, MD, is Clinical Assistant Professor at the University of Maryland School of Medicine, and he is in private practice with Katzen Eye Group in Baltimore. He states that he holds no financial interest in the products or companies mentioned herein. Dr. Katzen may be reached at (443) 632-2898; bkatzen@katzeneye.com.
Robert M. Kershner, MD, MS, FACS, is Clinical Professor of Ophthalmology at the John A. Moran Eye Center of the University of Utah School of Medicine in Salt Lake City, and he is President and CEO of Eye Laser Consulting in Boston. He states that he holds no financial interest in any of the products or companies mentioned herein. Dr. Kershner may be reached at kershner@eyelaserconsulting.com.
Donald N. Serafano, MD, is in private practice in Los Alamitos, California, and is Clinical Associate Professor of Ophthalmology at the University of Southern California in Los Angeles. Dr. Serafano is a clinical investigator for and has received a research grant from Alcon Laboratories, Inc., but he states that he holds no financial interest in any of the products mentioned herein. Dr. Serafano may be reached at (562) 598-3160; serafano@gte.net.
1. Singer J. Topographic corneal analysis of cataract incisions: the true picture. MVP Video Journal of Ophthalmology. 1993 December;9:6.
2. Fine IH, ed. Clear Corneal Lens Surgery. Thorofare, NJ: Slack Inc.; 1999.
3. Arshinoff SA. Dispersive-cohesive viscoelastic soft shell technique. J Cataract Refract Surg. 1999;25:167-173.
4. Kershner RM. Refractive Keratotomy for Cataract Surgery and the Correction of Astigmatism. Thorofare, NJ: Slack, Inc.; 1994.
5. Kershner RM. Keratolenticuloplasty. In: Gills JP, Sanders DR, eds. Surgical Treatment of Astigmatism. Thorofare, NJ: Slack, Inc.; 1994: 143-155.
6. Kershner RM. Optimizing the refractive outcome of clear cornea cataract surgery. In: Agarwal S, Agarwal AT, Agarwal A, et al, eds. Phako, Phakonit and Laser Phako—A Quest for the Best. Dorado, Republic of Panama: Highlights of Ophthalmology; 2002: 85-104.
7. Kershner RM. Correction of astigmatism in clear cornea cataract surgery. In: Gills J, ed. A Complete Surgical Guide for Correcting Astigmatism. Thorofare, NJ: Slack, Inc.; 2002: 49-64.
8. Kershner RM. Clear corneal cataract surgery and the correction of myopia, hyperopia and astigmatism. Ophthalmology. 1997;104:381-389.
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