Capsulorhexis forceps are used in cataract surgery to remove a circular portion of the anterior surface of the capsular bag that holds the patient’s natural lens. If you’re not squeamish, you can view this procedure here.
Each surgeon has their own preferences about how they want their forceps configured. These instruments are typically separated into several different components. Starting at the tip, the “working end” of the forceps, the tip that grasps the patient’s capsular bag is available in several different configurations. First, the tip can be anywhere from very sharp to very blunt, and everything in between. Sharp, or cystotome, tips, are preferred by some surgeons because they can be used to puncture the capsular bag, and then to complete the circular tear. Usually the puncture is made with a sharpened, bent needle, but the sharp tips can be used instead, often saving the surgeon some time during this “poke-and-go” procedure.
However, some surgeons prefer to minimize the number of sharp objects they insert into the anterior chamber, and prefer to use a less sharp tip, often referred to as a Utrata forceps. This triangular shaped head has lightly serrated or textured surfaces to ensure a solid grip on the capsular tear. Rounded, blunt tips are often referred to as O’Gawa type tips.
One more feature about the tips, then we’ll move on. Some surgeons like to have a notch on the interior surface of the tips to help ensure a good grip on the capsular tear. These are referred to as Pierse type tips.
The tips of the forceps are attached to an angled shank, which is usually between 11 and 14mm in length, and attached to the body of the forceps at about a 45 degree angle. The shanks are oftentimes straight, but are also available in curved or vaulted configurations. Some surgeons prefer the curved version because the curvature makes damaging contact with the inside surface of the cornea, or the endothelmium, less likely. Unlike many human body parts, the endothelium does not regenerate after it has been damaged. So it is imperative that the surgeon be very careful not to damage this delicate surface during cataract surgery. The vaulted shanks simply have a more pronounced curve to accommodate different surgeon’s preferences.
The handle, or body of the capsulorhexis forceps are typically found just in two configurations. One is the standard flat handle, which allows for stable control of the tip, and the other is a rounded configuration, which some surgeons prefer because it allows them to have rotational control of the tip without significant movement of their arm or wrist.
Most recently, decreasing incision sizes during cataract procedures has given rise to Micro Incision Cataract Surgery (MICS) instruments, and the capsulorhexis forceps have changed along with them.
Below are a few characteristics of commonly referred to types of capsulorhexis forceps:
Utrata: Semi-sharp, triangular shaped tips with gripping anterior surface. Typically also has a flat handle
Lehner-Utrata: These usually have a barrel shaped, knurled handle, Utrata type tips, and curved shanks.
Nevyas: Typically have sharp, cystotome tips for use in the “poke-and-go” method
O’Gawa: Characterized by longer but rounded, blunt tips
Pierse: Has notched tips