Surgeon details pterygium surgery technique with auto-limbal conjunctival grafting
The technique minimizes pterygium recurrence after surgery.
Pterygium surgery may be required to improve vision or cosmetic appearance or for symptomatic relief, and often it is challenging both intraoperatively and postoperatively. When pterygium and cataract surgeries are staged as two separate procedures, the significant optical benefits of first performing pterygium excision, including decreased corneal topographic astigmatism and improvement in aberrations, can contribute to better IOL calculations and optimal vision following the second stage cataract surgery.
However, a major surgical challenge and one of the most common complications of pterygium surgery is postoperative recurrence. Although an expanding list of surgical techniques is currently available, there is no consensus on a single ideal surgical procedure. The spectrum of procedures includes pterygium excision (wide excision or mini excision), usually combined with various grafting techniques, use of conjunctival autograft or amniotic membrane, and attachment to the ocular surface to cover the exposed bare sclera using tissue adhesives or sutures, with or without the use of mitomycin C or 5-fluorouracil.
In this column, Dr. Coroneo describes his surgical technique of pterygium management, combined with ocular surface inflammation control to provide an overall excellent postoperative result while minimizing pterygium recurrence after surgery.
Thomas “TJ” John, MD
OSN Surgical Maneuvers Editor
Pterygium is a prevalent, largely ultraviolet light-related, sight- and cosmesis-blemishing disease for which a plethora of surgical approaches exist. Key concepts in our approach are control of ocular surface inflammation, reconstructive surgical techniques (rather than destructive), minimization of recurrence rates and attention to refractive outcomes. While there is a paucity of comparative data, a widely accepted technique is pterygium excision with auto-limbal conjunctival grafting. I use this technique routinely because it provides low recurrence and complication rates and excellent cosmesis, but it takes time and skill to perform. In a well-conducted, long-term, single-surgeon series, limbal-conjunctival transplantation had a 1% recurrence rate compared with 10% for conjunctival transplantation. This mirrors our experience. Tenon’s capsule is excised locally, but extended excision is not carried out. In primary pterygium excision, we do not interfere with the medial rectus sheath or check ligaments.
Before surgery, ocular surface health should be optimized with aggressive treatment of dry eye syndrome (a factor in recurrence) and timing of surgery to avoid the summer months. Important issues include education of the patient in sun protection and trainees in surgical technique.
Source: Coroneo M
After adequate anesthesia, topical brimonidine is used as a vasoconstrictor (without mydriasis). The leading edge of the pterygium is dried, and the pterygium head is excised using a 23-gauge needle-tip technique (Figure 1), minimizing the amount of corneal tissue excised. Vertical incisions down to the anterior stroma delineate the head to the limbus. A relatively superficial plane of dissection is created. A relatively rough stromal surface is left and reverts to a smooth surface after epithelial healing. Care is taken to minimize limbal damage as the limbus is approached, so that sclera is not excised.
The body of the pterygium is then excised:
- Excision occurs approximately 1 mm above and below the limbal crossing points to minimize recurrence risk at these sites.
- Excision of inflamed tissue, sometimes as far as the plica/caruncle but remaining superficial to the check ligaments and sheath of the medial rectus muscle (Figure 2), is essential to obtain good postoperative cosmesis.
- Excess Tenon’s capsule underlying this excised area is also trimmed, but “fishing” for Tenon’s by pulling on exposed connective tissue is avoided.
- Bleeding is minimized by use of an intraocular diathermy tip. Particular care is taken to check for bleeding points in and deep to the cut, conjunctival edges (Figure 3).
The bulbar conjunctival defect is measured, and the horizontal extent is judged with the eye in forced abduction (Figure 4). Graft size is marked on the superior bulbar region (Figure 5), and the graft often has a trapezoidal shape. The donor site can extend to the superior fornix by pulling upward on the superior blade of the speculum with a squint hook, which will help in the exposure. A thin flap is created (Figure 6) using Westcott-style spring scissors; we prefer those by Martin (35-822-11), and the rounded tips allow safe subconjunctival Tenon’s dissection. These are wrapped and sterilized separately and replaced if blunt.
The dissected flap is then reflected over the cornea, and excess Tenon’s is trimmed. Fine-toothed forceps are used to engage this tissue (Figure 7). Buttonholes can best be repaired with the flap in this position, as the knot is located on the under-surface of the graft. A Stroll wedge base is used to pull the graft inferiorly while the limbal region is dissected (Figure 8). Bleeding from perforating vessels in this area can be expected and controlled with the wedge. With the flap under gentle tension, the limbus is split, resulting in a crenellated edge as the palisades of Vogt are cut horizontally with Vannas scissors (Figure 9). The flap is then detached from limbus and slid across a moistened cornea using tying forceps, and it is then flipped over and orientated in the defect created by the pterygium excision. If the graft orientation is uncertain, it can be checked using trypan blue, which preferentially stains Tenon’s capsule instead of the epithelial surface (Figure 10).
While the graft can be secured with tissue glue, particularly for large grafts, we prefer sutures. We have found that 10-0 polyglycolic acid monofilament absorbable sutures (Sharpoint GA-966 or B. Braun, Safil G1048700) elicit minimal inflammatory response. Limbal sutures that take superficial bites of sclera are placed first, and all knots are buried (Figure 11). An extended-wear plano contact lens — PureVision (balafilcon A, Bausch + Lomb) — is placed at the end of the procedure, covering the limbal aspect of the graft. Postoperative medications include topical antibiotic, steroid and preservative-free diclofenac eye drops, four times daily and usually tapered after 1 week. Topical treatment is typically 4 to 6 weeks, and special attention is required to detect any early signs of corneal melting that can be induced by diclofenac. If excessive inflammation occurs, topical treatment is prolonged and topical cyclosporine may be introduced.
In recurrent pterygia, forced duction is used to determine tissue fibrosis and adhesion between the recurrence site and medial rectus muscle. If this is detected, the medial rectus muscle is isolated and freed from the adhesions. Such cases may require extensive grafts. In some cases with inadequate superior bulbar conjunctiva, the graft can be taken from the other eye. All recurrent cases receive hyperbaric oxygen for a week after surgery.
This technique has evolved and has a recurrence rate of about 1%. In cases with significant postoperative residual astigmatism, close surveillance with serial topography is maintained. After stabilization, refractive options are discussed.
1. Limbal-conjunctival transplantation is our preferred method. Extended Tenon’s excision is not required.
2. Look for dry eye syndrome and treat aggressively before surgery.
3. Try to avoid surgery in the summer or at times of high ambient UV.
4. A 23-gauge needle tip is effective at both complete pterygium head excision with minimal removal of normal cornea and also for “splitting” the limbus at the graft donor site so as to include some normal limbus in the graft.
5. Brimonidine minimizes bleeding.
6. 10-0 polyglycolic acid monofilament absorbable sutures are associated with minimal inflammation.
7. Minimizing postoperative inflammation is essential.
8. In recurrent pterygium, postoperative hyperbaric oxygen aids graft survival and is associated with a low recurrence rate.
9. Use a bandage contact lens postoperatively to minimize pain.
10. Refractive outcomes should be monitored and managed.
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- For more information:
- Minas Coroneo, BSc (Med), MB BS, MSc Syd, MD, MS UNSW, FRACS, FRANZCO, is professor and chairman of the Department of Ophthalmology, University of New South Wales, Sydney, Australia, and chairman, Genetic Eye Foundation, Sydney. He can be reached at firstname.lastname@example.org.
- Thomas “TJ” John, MD, is a clinical associate professor at Loyola University at Chicago and in private practice in Oak Brook, Tinley Park and Oak Lawn, Ill. He can be reached at email@example.com.
Disclosures: Coroneo reports he is the inventor of patents relating to VisionBlue and receives royalties from the sale of this product. John reports no relevant financial disclosures.