Pterygium Excision and Conjunctival-Limbal Autograft Transplantation: A Simplified Technique Kirti Nath Jha Professor of Ophthalmology Mahatma Gandhi Medical College & Research Institute,Pondy-Cuddalore main road, Pillaiyarkuppam, Pondicherry- 607402 Email: kirtinath.jha@gmail.com Phone: 0413-2615449 FAX: 91-413- 2615457
Introduction Pterygium is a common condition which many consider a relatively harmless disease and allow simple excision at the lowest level of expertise. [1, 2] This results in highest rate of recurrence. There is a need to popularize a simple, low-cost, universally accessible surgical technique associated with low recurrence. Conjunctival limbal autograft (CLAU) transplantation is one such technique with low recurrence (0-4 %). [3] Here we describe author's modification of pterygium excision and CLAU transplantation. This is a safe and effective method with no complications. [4] Surgical Technique We operate in a major operation theatre under operating microscope and use peribulbar anesthesia. We prepare skin with povidone iodine (Betadine) 5%. The eyelids are retracted by self-retaining wire speculum. A 4-0 silk superior rectus bridle suture is passed. 0.5 ml normal saline is injected under the Tenon's capsule under the body of pterygium using 26-gauge needle mounted on 2 ml syringe. Two 4-5 mm long radial incisions along the upper and the lower borders of the pterygium, starting from the limbus are made in conjunctiva and the Tenon s capsule. The pterygium and the Tenon s capsule between the two radial incisions is freed from the globe by blunt dissection. 4-5 mm away from the limbus the pterygium is cut between the two incisions. The head of the pterygium is avulsed from the cornea by the method of reverse stripping, using a pair of McPherson/ plain conjunctival forceps. It involves reversing the pterygium onto cornea and application of a slow and deliberate traction to the free end of the pterygium held parallel to the corneal surface. Once a clean plane of ' tear (pterygium-rehxis) ' is initiated at one edge of the head, the process is led around the pterygium-head by gently rotating the tearing-edge to lift the whole of pterygium off the cornea. We include into the torn pterygium a little of the clear corneal epithelium
lying beyond the pterygium cap. It is important during the process to get the correct plane of cleavage, and maintain a good grip along the whole width of the pterygium. (Figures 1 a-d). Fig 1: Dissection of conjunctival- limbal autograft and its placement on the conjunctival defect a. Subconjunctival saline injection b. Parallel conjunctival incisions c. Dissection of the graft from the underlying Tenon s capsule by rail-road technique, using a pair of iris repositer d. Cutting the graft from its upper part e. Dissection of limbal tissue f. The graft is sutured in place. Any remnant / a tag of tissue left over the cornea is scraped off using No 15 Bard Parker knife or simply pulled off with McPherson forceps. This method obviates use of a knife. Dense attachment of the head of a recurrent pterygium requires care. Fibrovascular tissue under the conjunctiva is dissected as far towards the canthus as possible; the tissue is excised leaving the sclera and the horizontal rectus muscle free from episcleral
tissue. For dissection in a recurrent pterygium with fibrosis around rectus muscle, we use a pair of muscle hooks to protect the muscle. Avoiding injury to muscle sheath and the episcleral vessels ensures bloodless field. Minimal bleeding is controlled by pressure with cotton tip applicators. We do not use cautery. The conjunctival-limbal autograft is harvested from the same eye. We beforehand measure the bare sclera in its radial and circumferential dimensions both at the limbus and at the canthus. The superior rectus bridle suture helps expose upper bulbar conjunctiva. A graft about 2 mm larger than the bare sclera, centered at 12 o clock meridian on the bulbar conjunctiva is marked with Gentian violet. The conjunctiva is elevated with the subconjunctival injection of saline. A pair of conjunctival scissors is used to make two radial incisions in the conjunctiva along the marks diverging towards the upper fornix. Tenon s capsule is avoided. About 2 mm above the limbus, through the 2 radial incisions, we insert under the conjunctiva 2 iris repositer one each from the opposite sides. The iris repositers railroad into each other s track to exit through the incisions on the other side. Pulling the iris repositors apart in opposite directions, i.e. the superior fornix and the superior limbus, dissects the conjunctival graft neatly from the Tenon s capsule. The conjunctival graft is cut at the forniceal end with a pair of sharp conjunctival scissors. It is folded down over the cornea and held stretched down with a pair of McPherson forceps. Use of a plane forceps during this step prevents buttonholing of the graft. Blunt dissection of graft downwards to the limbus and 1 mm onto the clear cornea with a Tooke s knife or flat, blunt end of a iris repositer completes the dissection (Fig 2 a). While the graft is kept stretched all along its width with a pair of plain forceps the conjunctival graft is excised in one sharp cut with a pair of Vannas scissors. Our method does not require depth-controlled incision on the cornea. During the excision of the graft, care is taken to include the limbal stem cells into the graft. The donor site is left bare.
The graft is transferred onto the bare sclera (Fig 2 b) without losing the limbal orientation. Branching pattern of conjunctival vessels and identification of palisade of Vogt help maintain the natural orientation of the graft epithelial side up. Four corners of the graft is sutured to the bulbar conjunctiva and the episcleral tissue with 4 interrupted 10-0 polyamide cardinal sutures. Additional sutures cover the scleral defect well. Graft can also be fixed with fibringlue or by glue-free suture-free technique. [5,6] In the glue-free sutureless technique we do not induce bleeding. We avoid glue-free sutureless technique for temporal pterygium. Bulbar conjunctiva grows over the donor site over 1-2 weeks. At the end of surgery antibioticsteroid ointment is inserted and overnight pad and patch is applied. We avoid ointment in the glue-free suture-free technique. Antibiotic-steroid eye drop 4 times a day is started from first postoperative day for 6 weeks. Non-steroidal anti-inflammatory tablet is prescribed if the patient experiences pain. Some conjunctival sutures fall off during first 2 weeks. At 2 weeks remaining sutures are removed under topical anesthesia. Conclusion There is a need to reorient training for pterygium surgery. Authors have described a simple modification of pterygium excision and conjunctival-limbal autograft transplantation (CLAU). This method is easy and simple but time-consuming. Fibrin glue technique reduces the time but increases the cost. Glue-free sutureless technique reduces both. References 1. Hirst L W. The treatment of pterygium. Survey of ophthalmology 2003; 48(2):145-80. 2. Sebban A, Hirst LW: Pterygium recurrence rate at the Princess Alexandra Hospital. Aust NZ J Ophthalmol 1991; 19: 203 6.
3. Basic and clinical science course, Section 8, External diseases and cornea. San Francisco: American Academy of Ophthalmology 2013-14; 369-89. 4. Jha K N. Conjunctival-Limbal Autograft for Primary and Recurrent Pterygium. MJAFI 2008; 64: 337-39. 5. Ratnalingam V, Lim Keat Eu A, Ng G L, Taharin R, John E.Fibrin adhesive is better than sutures in pterygium surgery. Cornea 2010; 29:485 89. 6. Wit D, Athanasiadis I, Sharma A, Moore J. Sutureless and glue-free conjunctival autograft in pterygium surgery: a case series. Eye 2010; 24: 1474 77.