In search of the sutureless closure

Take home

Stephen S. Lane, MD, describes his technique for using an ocular sealant, as well as cases where he finds it useful and superior to sutures.

By Stephen S. Lane, MD; Special to Ophthalmology Times

Clear corneal incisions quickly gained favor among cataract surgeons because they are easy to perform, require less time, and have minimal effect on astigmatism. In addition, if performed correctly, they are generally self-sealing.

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In spite of these benefits, wound leakage is more common than ophthalmologist may presume, with some reports showing incidence as high as 85%.^1-4 The inflow of ocular surface fluid through a fresh postoperative incision may allow bacteria to be introduced to the anterior chamber, and wound incompetence on the first postoperative day has been found to be a significant risk factor for endophthalmitis.⁵

Wound integrity

Sutures have been considered the gold standard for incision closure, but 92% of surgeons responding to a survey by the American Society of Cataract and Refractive Surgery prefer a sutureless closure.⁶ This is likely due to the disadvantages of sutures which include: inflicting trauma on the cornea, time for suture placement in the operating room, induction of corneal astigmatism, extra office time for removal, and a creating a possible nidus for infection, inflammation, and neovascularization. In addition, the published wound leak with sutures is still almost 24%.⁴

A novel product (ReSure Sealant, Ocular Therapeutix) approved by the FDA last January was the first ophthalmic sealant for use in preventing fluid from leaking through the corneal incision following phacoemulsification. The sealant is a synthetic, polyethylene glycol hydrogel that is about 90% water after polymerization. The hydrogel molds around the irregularities of the de-epithelialized tissues and adheres via “lock and key,” rather than binding chemically to the ocular surface.

The U.S. Pivotal Clinical Trial evaluated the safety and efficacy of the sealant on 488 eyes that exhibited leakage using a specialized pressure gauge at the time of cataract surgery.⁷ These patients, from 24 ophthalmic clinics in the United States, were randomly assigned to receive either the sealant (n = 305) or a nylon suture (n = 183) at the main incision site. Incision leakage was evaluated at 1, 3, 7, and 28 days postoperatively.

The sealant demonstrated statistically significant superiority over sutures, with only 4.1% of eyes in the sealant cohort exhibiting leakage of the wound with provocation, compared with 34.1% in the suture group. The overall incidence of device-related adverse ocular events was also significantly lower for patients treated with sealant (1.6%) versus patients treated with sutures.

Technique

Though there are a few ways to apply the hydrogel, what works for me is the following: after IOL placement, I fill the eye to a physiologic IOP through one of the paracentesis. The surgeon may want to underfill the eye slightly to avoid any leakage.

The incision site is then thoroughly dried with a sponge. Once the incision site is completely dry, I pick up the mixing tray and hold it in view under the microscope. I add two drops of the diluent, consisting of water and buffer salts, to the blue deposit in one of the wells. This deposit contains the crosslinking agent, Trilysine, as well as the blue visualization aid to assist in application over the incision. Using the foam tip of the provided applicator, I rapidly mix the solution with the white deposit, polyethylene glycol (PEG), for 3 to 5 seconds until the material is liquefied. At this point, the material must be applied within the next 8 seconds as polymerization on the ocular surface occurs quickly.

The same applicator sponge that was used to mix the product should be sufficiently saturated to apply it. I like to start in the middle of the incision, and apply the product in a figure-eight pattern to cover the incision entirely and with complete coverage over the peripheral margins. During application, it is important not to press on the wound with the applicator, but rather softly place the material over the incision.

Once the sealant has been allowed to polymerize completely for 20 seconds after application, I inflate the eye through my side-port incisions to reform the anterior chamber to normal pressure. I watch the incision site and use a sponge at the conclusion to gently press the edges of the posterior aspect of the wound, ensuring there is no leakage. If I find that I did not apply an adequate amount of hydrogel on the incision, I use the second provided well to re-apply. The blue visualization agent dissipates within hours of application, and the remaining hydrogel sloughs off in the tears during re-epithelialization (typically 3 to 5 days), so there is no need for removal.

While it is not possible to “burp” the incision site to reduce pressure once the sealant is in place, it would still be possible to burp a paracentesis without impacting the sealed incision site.

I am using the sealant on any incision that does not self-seal with mild stromal hydration, as well as larger wounds up to 3.5 mm, and any situation with an incision size of 5 mm of less, when I would have otherwise used a suture. One example would be a patient undergoing DSEK with an incision size of 4.5 mm, which would typically require a suture.

While clear corneal incisions are superior in many regards, they are susceptible to leakage. Even after the use of standard closure methods-such as sutures and stromal hydration-many incisions leak when subjected to external forces, such as eye rubbing or improper eye drop application.

It has recently been shown that a suture causes greater astigmatism, at least transiently, than the sealant would.⁸ This sealant prevents fluid egress significantly better than sutures, in my experience, while maintaining patient comfort and surgeon efficiency, and it is an excellent tool to have on hand.

References

1. Chee SP. Clear corneal incision leakage after phacoemulsification–detection using povidone iodine 5%. Case Report. Int Ophthalmology. 2005:26:175-179.

2. Mifflin MD, Kinard, K, et al. Comparison of Stromal Hydration Techniques for Clear Corneal Cataract Incisions: Conventional Hydration versus Anterior Stromal Pocket Hydration. Journal of Refractive Surgery. 2012;38:933-937.

3. Herretes S, Stark WJ, et al. Inflow of ocular surface fluid into the anterior chamber after phacoemulsification through sutureless corneal cataract wounds. American Journal of Ophthalmology. 2005;140;737-740.

4. Masket S, Hovanesian J, et al. Use of a calibrated force gauge in clear corneal cataract surgery to quantify point-pressure manipulation. J Cataract Refract Surg. 2013 Feb 21.

5. Wallin T, Parker J, Jin Y, Kefalopoulos G, Olson RJ. Cohort study of 27 cases of endophthalmitis at a single institution. J Cataract Refract Surg. 2005;31:735-741.

6. Leaming DV. Practice styles and preferences of ASCRS members: 2003 survey. J Cataract Refract Surg. 2004;30:892-900.

7. Masket S, Hovanesian JA, Levenson J, Tyson F, Flynn W, Endl M, Majmudar PA, Modi S, Chu RY, Raizman MB, Lane SS, Kim T. Randomized comparison of a hydrogel sealant versus sutures for prevention of fluid egress following cataract surgery. Ophthalmology. Submitted for publication.

8. Uy HS and Kenyon KR. Surgical outcomes after application of a liquid adhesive ocular bandage to clear corneal incisions during cataract surgery. J Cataract Refract Surg 2013;39:1668–1674.

Stephen S. Lane, MD, is an adjunct professor of ophthalmology at the University of Minnesota, in practice at Associated Eye Care in St. Paul, MN, and a visiting faculty member of ORBIS International. Dr. Lane is a consultant to Ocular Therapeutix.