Corneal wound closure is a vital part of ophthalmic surgeries. This step should not be overlooked as it is key to preventing infection and maintaining the intraocular pressure (IOP).
At the end of a successful case, you may be ready to move on to the next part of your day. However, properly closing your corneal wound not only provides the eye with protection, but also can direct the amount of astigmatism and resultant visual acuity in the future.
Corneal lacerations
Corneal lacerations from ocular trauma are often encountered during your time as an on-call resident.
Below are recommendations for closing corneal wounds from trauma that can be used for minor repairs or full-thickness extensive corneal lacerations:1
- Any corneal laceration greater than 2mm needs to be sutured; even smaller ones that do not have a watertight seal with a bandage contact lens or cyanoacrylate glue should also be sutured in the operating room.
- Evaluate the entire laceration in order to plan your repair rather than haphazardly throwing stitches. This can often be a puzzle, and your plan may require modifications as you go along.
- Always make sure the needle is entering the tissue perpendicular to the tissue.
- Pass sutures at 90% depth in the stroma; passing at a shallower depth than this can cause the wound to gape, which can create serious problems in the future. Full-thickness passes can create a path for organisms to enter the eye and lead to infection.
- When planning your sutures, make sure to place longer sutures in the peripheral cornea in order to seal the wound. These longer sutures will also steepen the cornea, increasing the amount of surgically-induced astigmatism.
- As you move centrally, make sure to shorten the sutures to flatten the cornea, which will reduce the overall amount of astigmatism.
Wound hydration
Temporal corneal wound creation and closure are two of the most important steps of cataract surgery. Making the wound dictates how the entire operation will proceed.
Surgical pearls for properly hydrating corneal wounds include:
- Sealing the wound properly limits the risk of complications like hypotony, intraocular lens (IOL) dislocation, and endophthalmitis.2
- Don’t forget to seal the sideport incision.
- Make sure the cannula is securely attached prior to injecting the balanced salt solution. Accidental slippage of the cannula can cause trauma to the eye, including hemorrhage and perforation.
- To prevent the cannula from accidentally releasing, you can hold the base of the cannula while injecting the balanced salt solution—avoid aiming the cannula posteriorly and use a luer-lock syringe.3
Corneal transplants
Effective corneal wound closure is vital to any corneal transplantation surgery.
Steps to closing corneal wounds during corneal transplants include:
- Making sure the tissue is handled properly can make or break a corneal transplant surgery. Using the ideal tools for each unique case is an important factor to consider.
- For example, sometimes a toothed forceps can damage tissue but is necessary for certain cases where a good grasp is necessary (i.e., an edematous cornea).4
- Equal length and depth of sutures for corneal transplantation limits astigmatism and an overriding edge of the wound.
- The slipknot technique (1-1-1) is an alternative to the standard 3-1-1 tying technique. This technique allows for tension adjustment after the second throw and permanent suture placement with the third throw.4
Suture removal
Suture removal is also a very important step in ensuring adequate corneal wound closure in the future. In order to prevent wound dehiscence after suture removal, it is prudent to place single interrupted sutures, especially while still learning keratoplasty techniques.5
Additionally, it is advised to avoid premature removal of sutures to prevent wound dehiscence and not to pass the knot through the graft-host junction to prevent possible disruption to the interface.
Final key points
Dr. Erin Sieck, a glaucoma specialist at Washington University in St. Louis, oversees her trainees during glaucoma surgery and cataract surgery. One of her most important recommendations for corneal wound closure is to “never leave sutures under tension.”
She states that doing this “causes the suture to cheese wire or retract over time. It’s better to spend the time re-placing your suture than to deal with potential complications from a leaking wound.”
Other key recommendations for closing corneal wounds are listed below, such as:
- Using a Weck-Cel sponge to apply pressure to the edge of the wound (also known as a modified Seidel test) can help determine if the wound is leaking and requires further intervention.
- Clinical signs of wound leakage to look out for after cataract surgery include ocular hypotony, corneal folds, shallow anterior chamber, poor vision, and choroidal effusion.7
- Management of wound leaks includes decreasing steroid drops, as they can delay wound healing, placement of a bandage contact lens, or using topical aqueous inhibitors, which will decrease the amount of aqueous fluid produced and ideally lessen the amount of fluid egress.
- Definitive surgical repair is required in cases of persistent leak, flat anterior chamber, persistently low IOP, or iris prolapse.7
Closing thoughts
Corneal wound closure is often the final step in ophthalmic surgery but is not one that should be hastily completed. A thorough check to ensure a lack of wound leak can save your patient from a variety of complications, including possible infection or hypotony.
Ensuring you have well-closed corneal wounds will also help you get a better night’s sleep after a long day of operating!
