Centricity Vision Inc., a global ophthalmic technology company and developer of the ZEPTO IOL Positioning System™, announced that a new study published in Clinical Ophthalmology demonstrated ZEPTO's precision pulse capsulotomy (PPC) preserves the endothelial cells of the cornea as well as continuous curvilinear capsulorhexis (CCC or manual capsulorhexis) in cataract surgery.
Most cataract surgeons use a phacoemulsification (phaco) system to break up the cataract prior to new intraocular lens (IOL) placement. Phaco is associated with a 5–20% loss of corneal endothelial cells at one to three months post-surgery. This is why preservation of endothelial cells is important. The new study confirms that endothelial cell loss is the same for PPC as it is for CCC.
In the head-to-head study by Vital et al, patients treated by experienced cataract surgeons using either PPC or CCC had the same degree of endothelial cell loss, well within the acceptable margin needed to prevent complications.
Creating a well-formed, centered capsulotomy is among the most difficult steps of cataract surgery, and it is essential for optimal IOL positioning and stability. By applying 12 micro-pulses of energy in just 4 milliseconds, ZEPTO enables surgeons to center the capsulotomy with 360-degree IOL overlap on the patient's visual axis for improved outcomes.
For this prospective multisite study, 67 subjects requiring surgery to remove cataracts were randomly assigned to be treated using either CCC (n = 33) or PPC (n = 34) by surgeons who each had at least 20 years of experience performing these types of procedures. Density of the endothelial cells of the corneas of the treated eyes were measured using specular microscopy images of the central corneal endothelium before the surgery and again at one- and three-months post-surgery. Damage to the corneal endothelium may lead to a decrease in the percentage of hexagonally shaped endothelial cells and an increase in the coefficient of variation (CV) in cell size amongst the remaining cells as they enlarge to compensate for lost cells. Thus, these two parameters were also measured before and after surgery. Corneal endothelial cell density and other parameters of endothelial cell heath were performed by an independent reading center in a masked protocol.
The findings showed:
- No statistical difference in endothelial cell density (ECD) was found between patients who received PPC or CCC at the one-month or three-month postoperative time points.
- No statistical difference in the percentage of hexagonal cells, or CV were found between patients who received PPC or CCC at the one-month or three-month postoperative time points.
- The use of PPC during cataract surgery does not result in any increased endothelial cell loss beyond that normally associated with this surgery.
These findings come on the heels of a previous study by Ifantides and Sretavan revealing benefits of PPC over CCC in the treatment of white cataracts. In the study comparing 15 cases of white cataract performed using CCC with 20 cases performed using PPC, PPC resulted in complete capsulotomies without tags or tears and intracapsular intraocular lens implantation with 360-degree capsular overlap in all 20 cases. Compared with CCC, PPC white cataract cases also demonstrated significant advantages in capsulotomy time, reduced use of trypan blue and ophthalmic viscosurgical device, and less overall procedural time.
"In order to provide cataract patients with the best possible long-term outcomes, it is important to choose the technology that supports precise, consistent results and protects endothelial cell health," said study co-author Mark Vital, MD. "ZEPTO's precision pulse technology meets both of those criteria. The fact that it also improves workflow efficiency is an added bonus."
Read the full press release here.
Source: Centricity Vision