January 2016




Pulse of ophthalmology: Survey of clinical practices and opinion

How are we constructing our clear cornea incisions?

by Mitchell Gossman, MD


Mitchell Gossman, MD


One-day postop toric intraocular lens with clear cornea incision Source: Mitchell Gossman, MD

Continuing the discussion of clear cornea incisions from the October 2015 issue, I wondered, how are we creating our clear cornea incisions? What instruments are we using? What construction method and width do we use? How are we securing them? Our goals are legion: A secure incision to eliminate leaks and reduce incidence of endophthalmitis and postoperative difficulties Efficient speed of making the incision Efficient speed of sealing the incision Low cost per case An incision size that creates a pleasing surgical experience with minimal fluid egress through the incision, minimal astigmatism effects, and allowing easy instrument entry and manipulation A survey was performed of 99 practicing ophthalmologists who volunteered to participate from the ranks of participants of the eyeCONNECTIONS online community and volunteers around the U.S. Responses are anonymous in order to encourage candor.

The first question was, What is your preferred instrument to make a clear corneal incision in most cases and why?

Among the recurring comments: Difficulty persuading the hospital or ASC to purchase diamonds Better feel with steel Better and consistent sharpness with diamond Prefer sapphire with equivalent sharpness at less cost than diamond Lower cost for steelalthough unclear if this refers to per-case cost including acquisition and maintenance costs (including outright breakage) or acquisition cost I use a steel keratome, specifically the Sharpoint 2.02.2 bevel-up angled blade. I used to prefer a diamond blade (Rhein Medical 3-D, St. Petersburg, Fla.) but switched to steel due to my own documentation of per-case cost being higher with diamond along with my sense of better sharpness of steel than in years past. Another factor is the very high acquisition cost when trying to please multiple surgeons with their preferred diamond blades. Surprising even myself, I have come to prefer steel because of the enhanced feel of entering the cornea, possibly greater ease of sealing perhaps due to the rougher faces of the incision with steel, and zero or trivial cost of switching blade styles or widths.

The second question was, If steel or diamond blade, how do you construct your incision?

Are safety and speed mutually exclusive? Perhaps, and a majority evidently feel this to be so since to create an initial perpendicular groove or create a three-planed incision in one pass does take extra time. There is nothing simpler than the in and out parallel to the iris of a steel keratome or self-beveling style diamond blade (e.g., Rhein 3-D or the Accutome Trapezoid series, Malvern, Pa.). I prefer the speed of the single-plane method and, when combined with the Wong way supraincisional pocket (see below) along with the maximum length of opposing incision lips afforded by this method with endothelial pump sealing the longer incision, I think there is no compromise in the seal.

Another consideration is the length of the incision. As we all know, too long means a tendency to compromise the view from corneal striae and too short promotes greater difficulty sealing as well as iris prolapse. Perhaps a simple approach with a predictable incision length with the straight in and out methods makes it easier to achieve just the right length, but no doubt the other methods, with experience, could achieve the same.

The third question was, Do you check incision integrity prior to taking steps to seal, i.e., if leak proof, leave it alone?

Say you have finished the case completely and inflated the globe, and when checking the main clear cornea incision, it is bone dry. What to do? On the one hand, to fix it, i.e., seal with your preferred methods, does take time and potentially could make it worse, reminding us of the advice If it aint broke, dont fix it. On the other hand, your normal seal method takes only a moment, and perhaps it will enhance security even more and promote a more lasting seal for the overnight period. The responses show an essentially even split on this.

The fourth question was, How do you seal your incision, first attempt?

(The total is less than 100% due to comments regarding combining multiple methods.) The fifth question was, What initial incision width, in millimeters, do you use for the phaco procedure?

Selection of incision size has to do with the particular phaco instrumentation you have at hand, the minimum incision size compatible with your favored intraocular lens inserter, and your personal feelings as to what is a more sealable incision and with minimal influence on astigmatism. Ive personally found the 2.2 incision to be a pleasing compromise of all factors and continue to use it after a period of using a 1.8 mm incision proved to result in more difficult-to-seal incisions, no doubt related to wound stretch and small tears during phaco and IOL insertion.

As you can see, there is a great deal of diversity in methods here.

Editors note: Dr. Gossman is in private clinical practice at Eye Surgeons & Physicians, St. Cloud, Minn. He has no financial interests related to this article.

Contact information

Gossman: n1149x@gmail.com