March 2020

CORNEA

Presentation Spotlight
Case series of novel recurrent pterygium treatment method


by Stefanie Petrou Binder, MD Contributing Writer




Top: This is a double-headed kissing pterygium in a patient with prior pterygium surgery 6 years earlier. Bottom: At 12 months postop, the cornea was clear with no signs of recurrence in this aggressive case.
Source: Tanya Trinh, MBBS

 

A novel treatment method for recurrent pterygium using a simple limbal epithelial transplantation (SLET) technique was presented by Tanya Trinh, MBBS. She described a case series that demonstrated SLET as not only a viable surgical option, but one that targets one of the key pathological processes in the development of pterygium. This case series is the first to present SLET as a treatment option for surface reconstruction of recurrent pterygium.
“Limbal stem cell disease has been proposed as one of the inciting events in pterygium formation,” Dr. Trinh said. “SLET permits the harvesting of less limbal stem cell tissue for ocular surface reconstruction, which may reduce the risk of iatrogenic stem cell disease. In this case series it has also permitted surgery to be restricted to the affected eye only, preserving the integrity of the other eye.”

Background

Pterygia are fibrovascular growths extending from the conjunctiva onto the cornea. Recurrence rates after primary pterygium surgery varies widely in the literature but can be as high as 30–88%.1 None of the various treatment methods preclude recurrences, however, some of the more popular techniques involve repeat conjunctival autografting, the use of amnion, and mitomycin-C application with relatively good efficacy.2,3
According to the literature, SLET was first described in 2012 for treating unilateral limbal stem cell disease.4 Healthy limbal stem cells are harvested from the unaffected eye or from the ipsilateral affected eye and transplanted onto the diseased corneal surface. Other studies document SLET for unilateral chemical burns, ocular surface squamous neoplasia, and primary pterygium excision.4–7

Surgical method

The SLET procedures in this case series were performed by the same surgeon. A crescent blade was used to isolate a healthy limbal strip of approximately 4 mm x 2 mm. The limbal tissue was then cut into about 10 pieces with Vannas scissors and stored in balanced salt solution.
The pterygium was excised in standard fashion with the aid of a 64-Beaver blade, Westcott scissors, and forceps. A 360-degree conjunctival peritomy was performed to expose the limbal sclera. Mitomycin-C 0.02% was applied for 2–3 minutes subconjunctivally, and the ocular surface was debrided of residual scarified tissue.
A layer of amnion was placed over the cornea, bare sclera, and down to the excised pterygium, secured with fibrin glue and Vicryl sutures. The harvested limbal pieces were secured with glue over the amniotic membrane, and a bandage contact lens was placed over the eye at the end of the surgery.

Case series

The case series included 10 patients in total (five male and five female patients), ages 23–79 years with a slight preponderance for Caucasian background. All of the patients had prior pterygia; 80% of patients had two or more prior pterygia with one patient having had five prior pterygium excisions. Average pterygium height was 6.38 mm and average width was 4.64 mm. All were graded as having moderate to severe elevation and severity and 40% had more than 75% involvement of the cornea.
All of the patients were followed for at least 6 months (average 6–38 months). Postop there was a transient rise in IOP that responded to medical treatment in 50% of patients and was attributed to topical steroid response. At 6 months follow-up there was one recurrence in the one patient with the highest number of pterygium excisions (five).
BCVA improvement was modest and likely related to the pre-existing astigmatism and scarring from prior pterygium surgery. Two patients had restoration of the limbal stem cell niche such that they were able to support a penetrating keratoplasty to improve vision by removing corneal scarring.
“In more aggressive or recurrent pterygia, SLET may be a more effective option than conjunctival autograft alone to address both pterygium recurrence and repopulation of the depleted limbal stem cell niche,” Dr. Trinh said. “SLET is a novel surgical option for the treatment of recurrent pterygia. The beauty of this procedure is that it allows the good unaffected eye to be preserved as many of these patients prefer not to have their ‘good’ eye touched. The procedure addresses a key pathological process in pterygium development and should be considered in aggressive and recurrent cases.”

About the doctor

Tanya Trinh, MBBS

University Health Network
Donald K. Johnson Eye Institute
Toronto, Canada

References

1. Hacioglu D, Erdol H. Developments and current approaches in the treatment of pterygium. Int Ophthalmol. 2017;37:1073–1081.
2. Katircioglu YA, et al. Comparison of two techniques for the treatment of recurrent pterygium: amniotic membrane vs. conjunctival autograft combined with mitomycin C. Semin Ophthalmol. 2015;30:321–7.
3. Kenyon KR, et al. Conjunctival autograft transplantation for advanced and recurrent pterygium. Ophthalmology. 1985;92:1461–70.
4. Sangwan VS, et al. Simple limbal epithelial transplantation (SLET): a novel surgical technique for the treatment of unilateral limbal stem cell deficiency. Br J Ophthalmol. 2012;96:931–4.
5. Mittal V, et al. Successful management of severe unilateral chemical burns in children using simple limbal epithelial transplantation (SLET). Br J Ophthalmol. 2016;100:1102–8.
6. Mittal V, et al. Primary simple limbal epithelial transplantation along with excisional biopsy in the management of extensive ocular surface squamous neoplasia. Cornea. 2016;35:1650–1652.
7. Hernandez-Bogantes E, et al. Minor ipsilateral simple limbal epithelial transplantation (mini- SLET) for pterygium treatment. Br J Ophthalmol. 2015;99:1598–600.

Relevant disclosures

Trinh
: None

Contact

Trinh: Tanya.Trinh@gmail.com

Case series of novel recurrent pterygium treatment method Case series of novel recurrent pterygium treatment method
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