What am I looking for when I inspect Zepto at the start of surgery?
Dislodged push rod – Zepto is shipped with the tip of the push rod pre-set to slightly stretch the nitnol capsulotomy ring. This pre-set ensures the Zepto tip elongates and becomes narrow for corneal entry when the push rod is moved forward by the surgeon using the finger slider. In rare cases, the push rod may be dislodged from the nitinol capsulotomy ring during shipping or instrument set- up. If this is observed, do not use the unit. Do not attempt to re-set the push rod as this will damage the capsulotomy ring.
Foreign material – Zepto is thoroughly cleaned prior to packaging and shipment. However, fibers and other foreign material from the surgical environment can occasionally attach to the nitnol capsulotomy ring edge during setup. If this occurs, foreign material may be carefully removed using fine forceps without touching the suction cup or capsulotomy ring. If the material is not removable, a new Zepto handpiece should be used. Mis-shapened capsulotomy ring and / or broken lead attachment – The Zepto handpiece is shipped with a protective cover over the tip. If physical damage to the capsulotomy ring and electrical leads are observed, the unit must not be used.
Which capsulotomy sizes are available?
The current version of Zepto produces a mean capsulotomy diameter of 5.2mm. A version for pediatric capsulotomy is being pursued.
What type of surgical cases should I do first with Zepto?
Based on the experience from thousands of cases worldwide, the manufacturer strongly recommends that the surgeon starts with routine, uncomplicated cases with an anterior chamber depth of 2.5 mm to 3.75 mm and a pupil of at least 7 mm in diameter. Once the basics of positioning horizontally on the capsular plane, observing bubble flow for full suction, and proper Zepto release and float- off have been mastered, more challenging cases may be undertaken.
How shallow a chamber can I use Zepto?
The Zepto suction cup is 1.2 mm in height and has a diameter of 6.0 mm. Care should be exercised depending on the clinical situation.
How deep a chamber can I use Zepto?
The surgeon may compensate for a deeper chamber by choosing a more posterior location for the primary incision and by minimizing OVD use. Surgical judgement should be used in all cases, as Zepto must be able to reach and appose to the capsule surface in order to produce a capsulotomy.
Can Zepto be used in cases with poorly dilated pupils?
Yes. The elongated Zepto tip may be slipped under the iris distally and then opened up to slide under the iris 360°. The silicone suction cup shields the iris tissue from the Zepto capsulotomy element.
Can Zepto also be used with pupil expansion devices?
Yes. Zepto may be used with pupil expansion devices.
Why do I need to be careful about pupils between 5.5 and 6.5mm in diameter when using Zepto?
The Zepto suction cup is 6.0 mm in diameter and pupils in the size range of 5.5 to 6.5mm will mean that iris tissue is close to the suction cup and can potentially be trapped by the suction.
For pupils smaller than 5.5 mm, Zepto can be slid under the iris before suction is engaged and there is no danger of iris tissue being captured by the suction.
For pupils larger than 6.5 mm, the iris tissue will not be in close proximity to the suction cup and will not be captured by the suction.
What should I do if iris is trapped by suction?
Push the roller dispenser forward as is normally performed to release suction. Note that the OVD may cause the iris to remain sticking to the suction cup even after release. If needed, iris tissue may be freed by a second instrument through the sideport incision or by introducing more OVD to separate iris tissue from the suction cup.
Any recommendations for entry through the corneal incision?
It is helpful to stabilize the eye while Zepto is inserted through the incision. A Thornton ring is recommended. Some surgeons use a second instrument in the sideport incision to help stabilize the eye. In addition, place a small amount of OVD just outside the incision and/or on the elongated Zepto tip to lubricate entry. Surgeons have found this useful with 2.2 mm incisions.
Which OVD can I use with Zepto?
All OVDs with a viscosity less than or equal to of 300,000 mPas (or 300,000 cps) can be used. Do not use with Healon 5 or Healon GV or similar.
Is there any difference between using OVDs with low and medium viscosities?
The response of OVDs with different viscosities to suction will be different. With low viscosity OVDs, full suction will be established more quickly, fewer bubbles may be seen, and these bubbles will flow significantly faster, requiring more care in visual monitoring.
Will Zepto work without OVD?
We do not recommend using Zepto without OVD in the anterior chamber. Although Zepto can create high quality capsulotomies in the presence of BSS only, there will be no bubble flow that is normally present in the OVD as suction is developing. As a result, it is difficult for the surgeon to confirm full suction visually.
Can Zepto be re-used?
No, the nitinol capsulotomy ring is capable of only one capsulotomy. Attempted re-use will not result in another capsulotomy. The ring will instead be damaged and may cause patient harm.
Can I use Zepto through a scleral tunnel?
Zepto is designed to be used through a clear corneal incision. Although Zepto has been used through a scleral tunnel incision, it is not recommended.
What is the best way to move Zepto to the desired capsulotomy position?
After pulling back the push rod and allowing Zepto to re-circularize, leave the push rod in the neck of the device with the push rod tip just proximal to (outside of) the nitinol capsulotomy ring (see picture). The push rod provides rigidity to the neck, facilitating Zepto manipulation side to side, and forwards and backwards. After the desired capsulotomy positioning is achieved, remember to pull the push rod all the way out as suction is applied and bubbles start flowing. Leaving the push rod in the neck will interfere with the development of full suction and the creation of a complete capsulotomy.
How can I get consistent results every time?
Zepto is designed to consistently and automatically produce a round, high quality capsulotomy at any desired capsulotomy location including on the patient’s visual axis. Its action hinges on achieving an optimal level of suction to produce even and complete capsule apposition to the nitinol capsulotomy ring. Surgeons experienced with Zepto universally advise allowing an extra few seconds after maximum suction is reached and bubbles have stopped flowing before delivering energy to create the capsulotomy. Likewise, after capsulotomy, they all counsel confirming Zepto float-off from the capsule by observing some OVD exit at the incision. This prevents Zepto removal before full release from the capsule, which can inadvertently damage the capsulotomy. Consistent practice of these Zepto operating guidelines will help ensure a great outcome every time.
Can Zepto be used for pediatric capsulotomies?
A version of Zepto for pediatric capsulotomies (Zepto-PEDSTM) is in development.
Can Zepto be used for posterior capsulotomies?
The current version of Zepto is not designed to reach into the capsular bag to create a posterior capsuolotomy and should not be used for this purpose. With the appropriate device modifications, the technology can in principle be used for posterior capsulotomy. A version of Zepto for posterior capsulotomy is under consideration.