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EW CORNEA 58 by Rich Daly EyeWorld Contributing Writer July 2017 as well as when patients are losing vision from induced astigmatism, in cases of symptoms of redness and irritation with a history of progres- sion, and in those who will need cataract surgery in the near future. The latter patients need a stabilized corneal surface for more accurate IOL calculations. In situations where the pteryg- ium is removed prior to cataract surgery, Allan Slomovic, MD, Marta and Owen Bris Endowed Chair in Cornea and Stem Cell Research, and professor, Department of Ophthal- mology and Visual Science, Univer- sity of Toronto, Ontario, typically waits 3 months and then checks topography and biometry before performing cataract removal. It is important that corneal topography is stable prior to proceeding with cataract surgery. In a study that Dr. Slomovic presented at the Canadian Ophthalmological Society annual meeting, he found that (1) pterygi- um surgery reduces the topographic and refractive astigmatism (p=0.05), thereby making cataract biometry more accurate; (2) best corrected vi- sual acuity improved after pterygium surgery (p=0.02); and (3) pterygium surgery reduced higher order aberra- tions caused by the pterygium. Another, less common indica- tion for removal typically occurs with aggressively recurrent pterygia, where there may be traction on the extraocular muscles or on the globe itself. This may result in symptomat- ic diplopia. In cases of either pinguecula or pterygia, Virender Sangwan, MS, director, Centre for Ocular Regenera- tion, Hyderabad, India, will excise if it is cosmetically bothersome to the patient. However, in pinguecula cases where the patient is not worried about cosmesis but scared that it may progress and cause blindness, Dr. Sangwan reassures the patient that pinguecula and pterygia prog- ress very slowly. Primary technique For primary pterygia, Dr. Suh per- forms the excision with conjunctival autograft and secures the autograft with Tisseel glue (Baxter Healthcare, Deerfield, Illinois). "The benefit of glue is that the patient is much more comfortable Pterygium surgical approaches A myriad of techniques has been described regarding methods of pterygium surgery. A thorough resection of Tenon's in the area of the pterygium is a universal tenant since the pathological component of pterygia involves elastic degeneration of the Tenon's capsule. A report by the American Academy of Ophthalmology (AAO) was published regarding the options and adjuvants in surgery for pterygium. 1 Fifty-one randomized control studies comparing bare sclera excision, conjunctival or limbal autograft, intraoperative or postoperative mitomycin-C (MMC), and amniotic membrane transplantation were reviewed. The paper concluded that bare sclera excision of pterygium resulted in a significantly higher recurrence rate than excision with certain adjuvants. Conjunctival or limbal autograft was superior to amniotic membrane graft surgery in reducing recurrence risk, combined use of conjunctival or limbal autograft with MMC further reduced the recurrence rate compared to any of the entities used alone, and the optimal parameters for using MMC required further study. Physicians should be cautious regarding MMC use as vision-threatening complica- tions including scleral thinning, ulceration, and delayed conjunctival epithelialization were only associated with MMC. Since this AAO paper, additional techniques and studies have been published. When a pterygium recurrence occurs, it is important that the surgeon note whether the original lesion may have been a pseudo-pterygium and in fact, a manifestation of conjunctivalization from limbal stem cell deficiency. These cases require an alternative approach that addresses the lack of limbal stem cells to serve as a barrier to the progression of conjunctival vessels. John Hovanesian MD, Leejee Suh MD, Virender Sangwan MD, and Allan Slomovic, MD, discuss indications for pterygium and pinguecula removal, pearls for the surgical treatment of primary and recurrent pterygia, timing of the surgery when a patient has a co-existing cataract, and their preferred perioperative medical management in this month's "Cornea editor's corner of the world." Reference 1. Kaufman SC, et al. Options and adjuvants in surgery for pterygium: A report by the American Academy of Ophthalmology. Ophthalmology. 2013;120:201–8. Clara Chan, MD, FRCSC, FACS, Cornea editor Cornea editor's corner of the world Surgeons describe the approaches they credit with the best results for removing the unwanted tissue T here are almost as many approaches to pterygium re- moval as there are surgeons doing it. But that variety has allowed insights on effective approaches. "It's wrong to suggest that there is one preferred technique and that others are inferior," said John Hovanesian, MD, clinical faculty, Jules Stein Eye Institute, University of California, Los Angeles. "There are a number of different techniques for pterygium surgery with which different surgeons have been very successful." Dr. Hovanesian, who coau- thored a white paper for the ASCRS Cornea Clinical Committee describ- ing his pterygium excision tech- nique, 1 noted that surgeons' strong connection to a particular approach usually stems from positive experi- ences it has provided. Surgical management of both pterygia and pinguecula begins with deciding when it is appropriate to operate. Leejee Suh, MD, Miranda Wong Tang associate professor of ophthalmology, and director of the cornea and refractive surgery division, Harkness Eye Institute, Co- lumbia University, New York, excises the pinguecula when the patient is irritated from it, such as contact lens users and for those with recurrent inflammation in the area. Dr. Suh re- moves pterygia for the same reasons, and the cosmesis postop is much better," Dr. Suh said. As an additional preventative step against recurrence, Dr. Hovane- sian places a strip of amniotic mem- brane in the subconjunctival space surrounding the excision site. "I don't make an autograft layered on top of the amniotic membrane but around that is the patient's own conjunctiva," Dr. Hovanesian said. He undermines it with a blunt dissection to create a potential space and tucks in a layer of amniotic membrane. Dr. Hovanesian's ap- proach stems from previous findings that recurrence comes from the sur- rounding tissue and Tenon's fascia, which grows exuberantly and forms into pterygia. "Placing this amniotic mem- brane in contact with that surround- ing tissue seems to inhibit that," Dr. Hovanesian said. Recurrence rates with the technique are 1%, com- pared to the 5% standard recurrence rate when only conjunctival auto- graft is used. Recurrent technique For recurrent pterygia, Dr. Suh always uses mitomycin-C (MMC) and takes great care to separate the underlying Tenon's with selec- tive tenonectomy and then uses a conjunctival autograft if there is still enough conjunctiva or amniotic membrane. "I secure the conjunctival auto- graft with Tisseel glue, but if there is a large area to cover, I may place some Vicryl sutures," Dr. Suh said. In both primary and recurrent scenarios, Dr. Suh avoids overly cauterizing (i.e., bleaching out the scleral vessels) and going all the way to the caruncle for excision. In recurrent pterygia that have not responded to a conjunctival autograft plus/minus amniotic mem- brane transplantation and MMC application, Dr. Slomovic recently started performing simple limbal ep- ithelial transplantation (SLET) with MMC application. It may also be the procedure of choice in the future for double-headed pterygia. "The benefit of a SLET is you are harvesting a lot less limbal tissue," Dr. Slomovic said. Dr. Sangwan defines recurrence as cases where pterygium excision failed once among his own patients

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