EyeWorld Asia-Pacific September 2020 Issue

FEATURE 16 EWAP SEPTEMBER 2020 Dr. Starr said there are a lot of treatment recommendations based on severity and subtype. Treatment recommendations put forth by the ASCRS Cornea Clinical Committee largely follow the TFOS DEWS II treatment recommendations, with the difference being that you may have to act a bit more aggressively in a pre-surgical patient. Dr. Starr noted the identification of both visually significant ocular surface disease and non-visually significant ocular surface disease. Many will have non-visually significant ocular surface disease, he said, which doesn’t necessarily require you to cancel surgery and do aggressive treatment. However, it’s important for the patient to be aware of this prior to surgery. If you don’t tell them prior to surgery and it gets worse afterward, it’s considered a complication, he said. Meanwhile, visually significant ocular surface disease needs to be treated and reversed prior to surgery, Dr. Starr said, which can delay the surgery. Dr. Epitropoulos said she’s had excellent results reducing inflammation with immunomodulators, often in conjunction with a short course of a steroid and high-quality omega-3 supplements. It’s important to unblock the glands, especially prior to cataract or refractive surgery, and this can be done by heating and evacuating the glands with thermal pulsation treatment or using a handheld instrument Cordelia Chan, MD Consultant eye surgeon & partner, Eye Surgeons @ Novena Mount Elizabeth Novena Specialist Centre 38 Irrawaddy Road #09-28, Singapore 329563 drcordeliachan@gmail.com ASIA-PACIFIC PERSPECTIVES P terygium surgery was delegated to the most junior doctors in the department when I was a resident in the early 1990s. The surgery was performed sans surgical microscope in a procedure room adjacent to the outpatient clinics. The pterygium head was avulsed, the body excised and the sclera left bare. We saw recurrences in more than 80% of cases. Fortunately, there has been a change in mindset in pterygium management over the years, with the disease being accorded the attention and respect it deserves. Pterygium surgery is no longer considered “simple” surgery. In the current landscape, patients with pterygium are presenting earlier for surgery where complete excision and prevention of pterygium recurrence alone are no longer sufficient. In many cases, modern pterygium surgery has assumed the role of aesthetic surgery where good cosmetic outcomes are expected. Techniques in pterygium surgery vary widely. They differ in the extent of excision of the pterygium and subconjunctival fibrovascular tissue, the methods of covering the bare scleral defect, and adjunctive treatments used. In the article “Removal of primary pterygium: Techniques and other considerations,” I read with interest the comment made by John Hovanesian, MD: “...the best substitute for conjunctiva is conjunctiva.” I cannot agree more. Conjunctival autografting has been my preferred technique for pterygium surgery for over two decades. In my hands, it gives the lowest recurrence rates and best cosmetic outcomes compared to other adjunctive methods. The key to successful conjunctival autografting is a thin, Tenon’s fascia-free conjunctival graft that is slightly oversized (about 1 mm all around) with respect to the bare scleral bed such that it sits tension-free when applied. Oversizing helps in overcoming the natural shrinkage and retraction of tissues after surgery. Conjunctival autografting is technically challenging and outcomes are surgeon- and technique-dependent. In a well-harvested conjunctival graft with minimal disturbance of Tenon’s capsule, the donor site epithelializes with little or no scarring. Examination of the donor site post-surgery often gives clues to how thin and Tenon’s- free the conjunctival graft was when excised. A pristine donor site is a hallmark of good surgery. I have not found it necessary to perform a large tenonectomy when excising the pterygium tissue, unlike the P.E.R.F.E.C.T (pterygium extended removal followed by extended conjunctival transplantation) technique described by Lawrie Hirst, MD. Instead, I excise sufficient Tenon’s and subconjunctival fibrovascular tissue to create an adequately sized bare scleral defect (about 8x8 mm in most cases) that can be easily covered by a conjunctival autograft harvested from the superior conjunctiva. Even in double (nasal and temporal) pterygia, adequate conjunctiva can usually be harvested to cover the bare scleral defects by splitting the graft into two. Alternatively, a conjunctival rotation autograft could be performed for one of the pterygia. I have found amniotic membrane transplantation to be inferior to conjunctival autografting in terms of cosmesis, and reserve its use in cases where there is insufficient conjunctiva to cover the bare sclera, as in cases of extensive scarring at the intended harvest site. I generally avoid the use of mitomycin-C in primary pterygium surgery for fear of its potential complications such as necrotizing scleritis, delayed epithelial healing, and corneal endothelial damage. The adjuvant use of cyclosporine A has been found to be efficacious in some reports, and is a safer alternative to mitomycin-C. Ultimately, good surgical technique with minimal manipulation of the tissues is key to a perfect outcome. References 1. Ti SE, et al. Analysis of variation in success rates in conjunctival autografting for primary and recurrent pterygium. Br J Ophthalmol . 2000;84:385-9. 2. Jap A, et al. Conjunctival rotation autograft for pterygium: An alternative to conjunctival autografting. Ophthalmology. 1999;106:67-71 3. Kheirkhah A, et al. Effects of mitomycin C on corneal endothelial cell counts in pterygium surgery: role of application location. Am J Ophthalmol. 2011;151:488-93. 4. Zhang Q, et al. Adjuvant use of cyclosporine A in the treatment of primary pterygium: A systematic review and meta-analysis. Cornea. 2018;37:1000-7. Editors’ note: Dr. Chan declared no relevant financial interests.