Adhesive provides comfort, protection in cataract surgery

Adhesives play increasingly important roles in ophthalmology, especially as new formulations are devised and new indications are investigated, according to two experts.

Both specialists spoke on the topic at the annual joint meeting of Ocular Surgery News and the Italian Society of Ophthalmology in Rome.

“Applied to cataract surgery, [hydrogel adhesives] provide effective wound closure, improved patient comfort and possibly protection against external contaminants,” Kenneth R. Kenyon, MD, OSN Cornea/External Disease Section Editor Emeritus, said.

The history of adhesives in ophthalmology extends back 50 years, when cyanoacrylates were used for structural support of corneal perforations and to arrest sterile stromal ulcerations.

“In a study published in 1980, we proved that the mechanism of these glues was not simply tectonic but also anti-inflammatory. I still use them for any type of progressive non-infected corneal ulceration,” Dr. Kenyon said.

The next development, 30 years later, was fibrin glue, originally designed for hemostasis.

“We use fibrin adhesives in ocular surface surgery because they have good tensile strength for at least a few days. Conjunctival, limbal and amnion grafts can be held in place till they adhere themselves, with no need for sutures,” Dr. Kenyon said.

In the last 5 years, new hydrogel adhesives have been developed. The OcuSeal Liquid Ocular Bandage (BeaverVisitec International) and the ReSure Adherent Ocular Bandage (Ocular Therapeutix) are both produced in the U.S. but approved and marketed only in Europe so far.

Advantages in cataract surgery

OcuSeal is a two-part dendrimer-based hydrogel. It is packaged as two separate components, powder and liquid, that are mixed in a specially designed applicator and activated at the time of surgery.

“The hydrogel film is then spread over the patient’s wound, where it interacts with the underlying tissue, forming in about 20 seconds a smooth, transparent, pliable protective film, lasting for 1 day to 2 days,” Dr. Kenyon said.

Matteo Piovella, MD, OSN Europe Edition Editorial Board Member, showed results of his multicenter clinical study sponsored by BeaverVisitec International to evaluate the safety and efficacy of OcuSeal. The liquid bandage was used for corneal sealing after cataract surgery in 151 eyes of 111 patients.

“Foreign body sensation 1 day after surgery was reported by only 15% of the patients. In 72 eyes where OcuSeal was not applied, the same type of discomfort was reported in 70% of the cases,” Dr. Piovella said.

No complications or adverse events were reported in the early postoperative period or during the 3 months of follow-up.

“Patient comfort during the initial healing of the wound is an important reason to use the ocular bandage. Another good reason, which is currently under investigation, is that it might protect the eye from postoperative infections. Clear corneal incisions were indicated in large studies as a risk factor for endophthalmitis, and OcuSeal might be an effective means to avoid this risk,” Dr. Piovella said.

Incorrect application of the ocular bandage was reported in 16 cases in the study. OcuSeal must be mixed for 5 seconds and then applied within 10 seconds, and because polymerization occurs within 30 seconds, a delay in application could lead to failure.

Both Drs. Kenyon and Piovella said there is a learning curve for using this product. Surgeons must learn how to perform the various stages of preparation and application quickly, precisely and efficiently.

Potential future applications

Wider use of OcuSeal in everyday surgical and clinical practice may be hindered by the cost of the product, currently in the region of $40 per application.

“With the limited reimbursements normally available for cataract surgery, it would be difficult to include the additional cost of the ocular bandage,” Dr. Piovella said. “But after experiencing its benefits, now I am using it in my cataract cases routinely.”

Dr. Kenyon said that OcuSeal was first approved in Europe for additional indications that have required reconsideration.

“It is certainly useful to apply as a means of sealing and improving comfort with cataract surgery, but it is not appropriate to apply following PRK or large corneal abrasions, as it might inhibit epithelial healing,” he said.

Indications are gradually being refined, and the potential applications for the ocular bandage in vitreoretinal, glaucoma, strabismus and LASIK surgery are also being investigated.

“It’s still a work in progress,” Dr. Kenyon said.

“There are several case studies currently ongoing in Europe on the various potential applications of OcuSeal. The future looks promising,” Dr. Piovella said. – by Michela Cimberle

Reference:

• Fogle JA, Kenyon KR, Foster CS. Tissue adhesive arrests stromal melting in the human cornea. Am J Ophthalmol. 1980; 89(6):795-802.

• Kenneth R. Kenyon, MD, can be reached at Eye Health Vision Centers, 51 State Road, Dartmouth, MA 02747; 508-994-1400; fax: 508-992-7701; email: kenrkenyon@cs.com.
• Matteo Piovella, MD, can be reached at Centro Microchirurgia Ambulatoriale, Via Donizetti 24, 20052 Monza, Italy; 39-039389498; fax: 39-0392300964; email: piovella@piovella.com.
• Disclosures: Drs. Kenyon and Piovella are consultants for BeaverVisitec International.

As the authors said, OcuSeal seems helpful in creating a barrier effect to prevent the leakage related to imperfect cataract incisions. A clinical study is currently ongoing in Alicante to give evidence of the efficacy of OcuSeal for this specific use. In conjunctival surgery, particularly in pterygium, strabismus and complex vitreoretinal surgery, it has also shown effective in decreasing the discomfort that follows the procedure. It is important, however, to point out that OcuSeal is not an adhesive and cannot be used to glue tissues together, but it is rather a bandage surgical device.

Further studies should be done to test the capability of OcuSeal to improve the postoperative discomfort following cataract surgery and to compare the efficacy of OcuSeal vs. sutures in closing leaky incisions following the cataract procedure.

– Jorge L. Alió, MD, PhD
OSN Europe Edition Editorial Board Member
Disclosure: Dr. Alió is a clinical research investigator for OcuSeal.