Management
Goals of management of an open corneal injury are to ensure a watertight globe to prevent hypotony and infection, reestablish original anatomy as much as possible, and lastly, restore visual function.[3]
Medical Management
Small self-sealing wounds may be treated with topical antibiotics alone, whereas slightly larger wounds may heal under a bandage contact lens (BCL).[3] A combination of these, along with patching and aqueous suppressants, is commonly used to medically manage very small lacerations and perforations.[12]
Corneal gluing with a variety of biocompatible materials can be used successfully to close corneal wounds. Fibrin glue (Tisseel; Baxter Healthcare, Deerfield, IL), often in conjunction with a BCL, can be used to close partial thickness corneal lacerations. The glue may prevent epithelial invasion of the wound.[22] Another study reported that corneal perforations <2 mm in diameter were more successfully treated with Tisseel fibrin sealant than larger injuries.[23] Isobutyl cyanoacrylate is another tissue adhesive commonly used to repair small corneal lacerations and perforations. In a retrospective study of corneal perforations <3 mm, 40.9% of eyes healed with application of cyanoacrylate alone, with a mean healing time of 33.4 days. Six eyes (27.3%) required reapplication of glue secondary to recurrent leaks or glue dislodgement.[24]
Given that both fibrin and cyanoacrylate glue dry quickly and require adeptness in the delicate application of a small amount of adhesive, a variety of glue application techniques have been described.[25] Surgical sterile plastic drape can be used as a tectonic patch and glued over a corneal perforation. Although not a permanent solution, this method can maintain anatomic integrity until a penetrating keratoplasty can be performed.[26] Others have reported using the sterile hard paper part of Tegaderm (3M, St. Paul, MN) associated with cyanoacrylate glue and pressing this onto the corneal perforation with glue on the underside.[27]
Newer synthetic materials are also being tested on corneal injuries. A photo-cross-linkable tissue adhesive made of hyaluronic acid has been used to repair linear and stellate corneal wounds. The adhesive is irradiated with argon laser beam to create a clear polysaccharide hydrogel patch.[28] In another study, an argon ion laser-activated biodendrimer adhesive was used to repair corneal lacerations in enucleated human eyes and was found to be comparable to interrupted suture repair in withstanding increases in intraocular pressure and maintaining wound integrity.[25]
Surgical Management
Delayed presentation of corneal trauma or severe injuries may result in corneal perforation and loss of corneal tissue. These injuries are more difficult to close by sutures and corneal grafting may be necessary but delaying this latter option until globe integrity has been achieved and inflammation has quieted can ensure a successful graft later.[29] Various techniques for closure have been reported over the last several years.
Amniotic Membrane Transplantation Amniotic membrane, which is used widely in ocular surface disease, provides mechanical protection, helps with reepithelialization, and decreases inflammation.[30] This biologic tissue has been used to cover corneal perforations, usually in nontraumatic cases.[31–33] The membrane can be sutured in place and covered with a BCL to help protect the vulnerable area.[31] Amniotic membrane transplantation has also been used in conjunction with fibrin glue initially plugging the perforation site.[32] Hyperdried cross-linked amniotic membrane may be more durable and provides longer substrate to allow for proper wound healing.[33] Recently, TachoSil (Takeda, Zurich, Switzerland), an absorbable fibrin sealant patch, sandwiched between 2 layers of sutured amniotic membrane has been successfully used to seal a corneal perforation >2 mm.[34]
Other Biologic Membrane Substitutes Other biologic membrane substitutes have also been described. A combined use of Tutopatch (irradiated bovine pericardium; Med&Care, Gdynia, Poland) with a clot of autologous eye platelet-rich plasma has been used to patch a perforation. The eye platelet-rich plasma, which contains several biologic active substances that may promote corneal healing, along with the inert bovine pericardium has been shown to heal noninfectious corneal perforations.[29] Another material used successfully to patch a corneal perforation is Neuro-Patch (B. Braun, Melsungen, Germany), which is a purified polyurethane material used primarily as a dural substitute in neurosurgery.[35]
Conventional Suture Repairing lacerations with 10–0 nylon interrupted sutures is the conventional way to treat corneal lacerations. The goal of suturing is to close the wounds with anterior and posterior edges apposed, without any override or underride. Full-thickness or near full-thickness interrupted suture bites are most ideal for wound closure.[3] Long, tight sutures near the periphery and shorter, more widely-spaced sutures centrally help preserve the natural curvature of the cornea to reduce postrepair astigmatism.[36] Air injected into the anterior chamber can be used as a tamponade to prevent aqueous leakage after suture repair of a laceration. C3F8 gas has been reported to be successful in preventing aqueous egress and allowing for effective tamponade at the wound edges,[37] but the goal of surgical suture repair of any corneal laceration should always be a watertight wound without needing extra measures.
Lamellar Transplantation In select cases of noninfectious perforation, deep lamellar keratoplasty has been described to not only reform globe integrity and decrease risk of infection but also achieve clear visual axis, with less risk than a penetrating keratoplasty.[38] Tectonic deep anterior lamellar keratoplasty can be performed using donor lamellar tissue sutured in a patch graft manner to close corneal perforations.[39] Patch grafting has been used in combination with amniotic membrane transplantation, with the membrane intended to decrease inflammation.[40]
Autografts When donor tissue is not available, autografting can be used successfully to patch corneal perforations. A unique method of repositioning a lamellar cornea-sclera rotational autograft has been reported to successfully patch<2.0 mm corneal defects.[41,42] Another elegant technique described uses a freehand-dissected central autointralamellar flap folded over a paracentral perforation and then an inlay lamellar graft placed over an entire previously performed superficial lamellar dissection. This technique allows for a clear visual axis preservation of corneal architecture.[43]
Scleral autoplasty has also been reported to successfully treat corneal perforations. An autologous scleral lamellar patch graft can be inlayed in the cornea where the perforation boundary was previously trephined and superficial keratectomy was performed. Autologous scleral patches have no risk of rejection and have been shown to clear over time.[44]
Preserved corneal tissue can also be used to patch corneal perforations when fresh donor tissue is not available. These corneal buttons can be preserved with a variety of techniques. Cryopreserved donor tissue kept frozen at -70°C and a tissue preserved in glycerin has been used successfully in repairing corneal defects.[39,45] Gamma-irradiated sterile corneas have also been used as corneal patch grafts with favorable intraoperative and postoperative outcomes, allowing for biological incorporation and clarity and providing longer shelf-life without the risk of infection.[46]
Int Ophthalmol Clin. 2013;53(4):1-10. © 2013 Lippincott Williams & Wilkins
