Year : 2000 | Volume
: 48 | Issue : 1 | Page : 21--4
Inferior limbal-conjunctival autograft transplantation for recurrent pterygium
AK Wong, SK Rao, AT Leung, AS Poon, DS Lam
Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
A K Wong
Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
Purpose: To study the safety and efficacy of inferior limbal-conjunctival autograft (LCAT) transplantation in the surgical management of recurrent pterygium.
Methods: Prospective non-comparative case series. Inferior limbal-conjunctival autografting was performed on 11 patients (11 eyes) with recurrent pterygium. Pterygium recurrence was considered a surgical failure.
Results: Recurrence of pterygium was noted in two (18.2%) eyes, after a mean follow up of 16.2 ± 0-9 months (range: 10 - 19 months). Neither recurrence required further surgical treatment. Nonprogressive pseudopterygium formation was noted at the donor site in five (45.5%) eyes.
Conclusion: Inferior LCAT appears to be a safe and effective option in the management of recurrent pterygium. In patients with suspected or proven glaucoma, this may be the procedure of choice, if mitomycin C is contraindicated.
|How to cite this article:|
Wong A K, Rao S K, Leung A T, Poon A S, Lam D S. Inferior limbal-conjunctival autograft transplantation for recurrent pterygium.Indian J Ophthalmol 2000;48:21-4
|How to cite this URL:|
Wong A K, Rao S K, Leung A T, Poon A S, Lam D S. Inferior limbal-conjunctival autograft transplantation for recurrent pterygium. Indian J Ophthalmol [serial online] 2000 [cited 2021 Jun 15 ];48:21-4
Available from: https://www.ijo.in/text.asp?2000/48/1/21/14860
Pterygium is a fibrovascular, wing-shaped encroachment of conjunctiva on to the cornea. Ultraviolet light-induced damage to the limbal stem cell barrier, with subsequent conjunctivalization of the cornea, is the currently accepted aetiology.[1, 2] Indications for surgery include visual impairment, cosmetic disfigurement, motility restriction, recurrent inflammation, interference with contact lens wear and rarely, changes suggestive of neoplasia. Surgical treatments advocated include simple excision, thiotepa drops, β-irradiation, intra- and postoperative mitomycin-C, conjunctival autografting, amniotic membrane transplantation (AMT), and combinations of the above methods.[3-9] The most common complication described, in all methods, is recurrence of the pterygium. Despite its efficacy in preventing recurrence, initial experience with mitomycin-C indicated the possibility of severe, sight-threatening complications.[10-12] Recent studies indicate fewer side effects with mitomycin-C, but the optimal concentration and duration of therapy are still being refined.
The use of conjunctival autografting following pterygium excision was first described by Kenyon et al in 1985. Since then, other reports have described recurrence rates of 3.8 - 39% with this procedure.[14-20] The importance of including limbal tissue in the conjunctival autograft, to reduce the recurrence rate, has been described in a recent report. Most studies in the literature describe the use of conjunctival and/or limbal autografts from the superior bulbar conjunctiva. A potential disadvantage of this approach is scarring of the donor site, which could compromise the success of any future filtering surgery, that might be required. Wiley et al evaluated regional heterogeneity in the limbal epithelium using immunohistochemical techniques. They reported broader regions with immunohistochemical characteristics of limbal epithelium in the superior and inferior limbus compared to the medial and lateral regions. We therefore performed pterygium excision with inferior limbal-conjunctival autograft transplantation (LCAT) for recurrent pterygium. In this report, we describe the safety and efficacy of this surgical approach.
Materials and Methods
In this prospective study, 11 consecutive patients (11 eyes) with recurrent pterygium were enrolled, between October 1997 and February 1998. Patient data including demographics, best-corrected visual acuity (BCVA) before and after surgery, characteristics of the pterygium (location, size and extent across the cornea, presence of inflammation, and details of previous treatment), intra-and postoperative complications, and recurrence of pterygium were recorded. All patients underwent pterygium excision and inferior LCAT by the same surgeon (AW). A standard surgical technique, essentially similar to that described by Kenyon et al, was followed. All surgeries were performed under peribulbar anaesthesia, using an operating microscope. The limbal-conjunctival autograft was 0.5 mm larger than the exposed scleral bed, in all dimensions. The limbus was excised with approximately 20% of corneal stroma, extending 0.5 - 1.0 mm into clear cornea. The graft was secured using interrupted 10-0 nylon sutures for the limbal margin and 8-0 vicryl sutures for the conjunctival margins. After surgery, ofloxacin eye drops, four times a day for one week, and prednisolone acetate eye drops four times a day for one month, were used. Postoperatively, a recurrence was defined as fibrovascular tissue crossing the corneoscleral limbus on to clear cornea in the area of previous pterygium excision.
The mean age of the 11 patients (7 males, 4 females) was 63.3 ± 3.1 years (range: 42-72 years). The clinical data are listed in [Table:1]. All patients had recurrent pterygium, which had been excised once in 8 eyes and twice in 3 eyes. Average extent across the limbus was 3.5 ± 0.2 mm (range: 2.5-5.0 mm). The size of the limbal-conjunctival autograft varied from 1.5 - 3 o' clock hours. The mean postoperative follow up was 16.2 ± 0.9 months (range: 10-19 months). Except for one patient (case 3), the others had a follow up greater than one year. At last follow up, 7 (63.6%) eyes had an improvement in BCVA, and BCVA was maintained in 4 (36.7%) eyes. No significant intraoperative complications were noted. A corneal dellen, due to the oedematous conjunctival graft, was noted in case 7 in the first postoperative week. The dellen resolved with frequent use of topical tear substitutes. Pseudopterygium formation at the donor limbus was seen in 5 (45.5%) cases. Recurrence of pterygium was noted in 2 (18.2%) eyes (cases 8 and 9), and occurred 4 and 3 months after surgery. They were across-the-graft, non-progressive, and did not require further surgery.
While the definitive management of a pterygium is surgical, the ideal adjunctive procedure is still to be determined. Studies have indicated that a pterygium occurs as a result of localized limbal dysfunction.[1, 2] A pterygium also exhibits features described in limbal stem cell deficiency states: surface inflammation, corneal vascularization, and conjunctivalization. An important complication after pterygium surgery is recurrence of the pterygium. A recurrent pterygium can be associated with decreased visual acuity (due to involvement of the visual axis and/or irregular astigmatism), extraocular motility restriction and symblepharon formation. The success of conjunctival autografting techniques that include limbal tissue in the graft, in treating primary and recurrent pterygia, has been highlighted in a recent review. Conjunctival autografts do not have a propensity for such long-term complications as scleral melting, sometimes seen after mitomycin-C usage in pterygium surgery. Disadvantages with this approach however, include the need to use an operating microscope, the need for greater surgical skill with a distinct learning curve, and surgical disturbance of the superior bulbar conjunctiva. Concerns exist about the outcome of future filtering surgery in such eyes. Since the report by Wiley et al described the presence of similar limbal characteristics in the superior and inferior regions, we performed LCAT from the inferior limbus.
The recurrence rates in other studies of limbal-conjunctival autografting after pterygium excision are listed in [Table:2]. These studies described LCAT from the superior limbus, and have a lower recurrence rate compared to the present study. This could be because of the greater technical difficulty in harvesting a graft from the inferior limbus, resulting in lower level of transfer of limbal cells. Also, the inferior limbus is exposed more to the deleterious effects of ultraviolet radiation, compared to the superior limbus, which is shielded by the upper lid. Thus, inferior limbal grafts may have a lower protective ability than superior grafts. The recurrence rate of 18% in this study is however, quite encouraging, considering that all patients underwent surgery for recurrent pterygium. The recurrence rate in this study also compares favorably with those reported in studies using mitomycin-C (5.9 to 42.9%).[13, 27] The use of amniotic membrane transplantation (AMT) also has a similar advantage of not disturbing the superior bulbar conjunctiva. A study comparing AMT with conjunctival autografting in recurrent pterygia, however, reported a significantly higher recurrence rate after AMT (37.5%) compared to conjunctival autografting (9.1%). In another study, Shimazaki et al described the use of AMT with limbal autografting in four eyes with recurrent pterygium and extensive symblepharon formation. Pterygium recurrence was noted in one eye. The authors state that the use of AMT helps suppress subconjunctival fibrosis and reduces the recurrence of symblepharon. However, they stress that limbal autografting is necessary to restore limbal function in these eyes.
Pseudopterygium formation at the donor site, noted in this study, is probably due to the surgical technique used. A similar occurrence has also been reported in a recent study describing limbal autografting from the clinically uninvolved fellow eye in chemical burns. The surgical technique used was similar to that in the present study, with the inclusion of corneal stroma in the limbal graft. The donor site developed a pseudopterygium, although the size of the excised limbal graft was only 1.25 o' clock hours. Excision of corneal stroma with the limbal graft could produce this healing response. Removal of the peripheral corneal stroma could result in delayed reepithelialization by the corneal epithelium, allowing conjunctival encroachment. In contrast, an earlier study reported the excision of conjunctival-limbal autografts as large as 12 mm (3 o' clock hours), without pseudopterygium formation at the donor site. The authors did not excise corneal stroma. We thus feel that pseudopterygium formation can be avoided or decreased by a more superficial dissection of the limbal epithelium, sparing the corneal stroma. However, none of the eyes in this study experienced progression of the pseudopterygium at the donor site, after a mean follow up of 16.2 ± 0.9 months. The pseudopterygium (Figure) had a concave superior border, indicating the extent of peripheral corneal stromal excision. A progressive pterygium usually has a convex superior border. Basti and Mathur also reported nonprogression of the pseudopterygium in their study. Since limbal tissue is relocated in the same eye in pterygium surgery, this type of transplantation does not weaken total limbal function.
While studies with larger numbers and longer follow up are required, we feel that this report provides encouraging results regarding the safety and efficacy of inferior LCAT in the management of recurrent pterygium. In this study, 10 (90.9%) patients had a follow up greater than one year (the other patient had a follow up of 10 months). Since 97% of recurrences after pterygium surgery are reported to occur within one year, we feel that the recurrence rate in this study is unlikely to increase with longer follow up.
In conclusion, our results of inferior LCAT after pterygium excision indicate that it is a safe and effective option in the management of recurrent pterygium. It may be the procedure of choice in patients with suspected or proven glaucoma, particularly if the use of mitomycin-C is also to be avoided. Inferior LCAT can also be considered in patients with recurrence after conjunctival grafting from the superior limbus.
|1||Dushku N, Reid TW. Immunohistochemical evidence that human pterygia originate from an invasion of vimentin-expressing altered limbal epithelial basal cells. Curr Eye Res 1994;13:473-81.|
|2||Kwok LS, Coronea MT. A model for pterygium formation. Cornea 1994;13;219-24.|
|3||Sebban A, Hirst LW, Kynaston B, Bain C. Pterygium recurrence rate at the Princess Alexandra Hospital. Aust NZ J Ophthabnol 1991;19:203-6.|
|4||Mackenzie FD, Hirst LW, Kynaston B, Bain C. Recurrence rate and complications after beta-irradiation for pterygia. Ophthalmology 1991;98:1776-81.|
|5||Joelson GA, Muller P. Incidence of pterygium recurrence in patients treated with thiotepa. Am J Ophthalmol 1976;81:891-92.|
|6||Singh G, Wilson MR, Foster CS. Long term follow up study of mitomycin eye drops as adjunctive treatment of pterygia and its comparison with conjunctival autograft transplantation. Cornea 1990;9:331-34.|
|7||Frucht-Pery J, Ilsar M, Hemo I. Single dose of mitomycin C for prevention of recurrent pterygium: Preliminary report. Cornea 1994;13:411-13.|
|8||Kenyon KR, Wagoner MD, Hettinger ME. Conjunctival autograft transplantation for advanced and recurrent pterygium. Ophthalmology 1985;92:1461-70.|
|9||Prabhasawat P, Barton K, Burkett J, Tseng SCG. Comparison of conjunctival autografts, amniotic membrane grafts and primary closure for pterygium excision. Ophthalmology 1997;104:974-85.|
|10||Rubinfeld RS, Pfister RR, Stein RM, Foster CS, Martin NF, Stoleru S, et al. Serious complications of topical mitomycin C after pterygium surgery. Ophthalmology 1992;99:1647-54.|
|11||Gupta S, Basti S, Corneoscleral, ciliary body, and vitreoretinal toxicity after excessive instillation of mitomycin C (letter). Am J Ophthalmol 1992;114;503-4.|
|12||Hayasaka S, Noda S, Yamamoto Y, Setogawa T. Postoperative instillation of low-dose mitomycin C in the treatment of primary pterygium. Am J Ophthalmol 1988;106:715-18.|
|13||Lam DS, Wong AK, Fan DS, Chew S, Kwok PS, Tso MO. Intraoperative mitomycin C to prevent recurrence of pterygium after excision: a 30-month follow-up study Ophthalmology 1998;105:901-4.|
|14||Rao SK, Lekha T, Mukesh BN, Sitalakshmi G, Padmanabhan P. Conjunctival-limbal autografts for primary and recurrent pterygia: Technique and results. Indian J Ophthalmol 1998;46:203-9.|
|15||Chen PP, Ariyasu RG, Kaza V, Labree LD, Me Donnell PJ. A randomized trial comparing mitomycin C and conjunctival autograft after excision of primary pterygium. Am J Ophthalmol 1995;120:151-60.|
|16||Koch JM, Mellin JB, Wauble TN. The pterygium-Autologous conjunctiva-limbus transplantation as treatment. Ophthalmlogy 1992;89:143-46.|
|17||Guler M, Sobaci G, Ilker S, Ozturk F, Muthi FM, Yildirim E. Conjunctival autograft transplantation in cases with recurrent pteryguim. Acta Ophthalmol (Copenh) 1994;72:721-26.|
|18||Shimazaki J, Yang HY, Tsubota K. Limbal autograft transplantation for recurrent and advanced pterygia. Ophthalmic Surg Lasers 1996;27:917-23.|
|19||Pulte P, Heiligenhaus A, Koch J. Long-term results of autologous conjunctiva-limbus transplantation in pterygium. Klin Monatsbl Augenheilkd 1998;213:9-14.|
|20||Mutlu FM, Sobaci G, Tatar T, Yildirim E. A comparative study of recurrent pterygium surgery:limbal conjunctival autograft transplantation versus mitomycin C with conjunctival flap. Ophthalmology 1999;106:817-21.|
|21||Wiley L, SundarRaj N, Sun TT, Thoft RA. Regional heterogeneity in human corneal and limbal epithelia: An immunohistochemical evaluation. Invest Ophthalmol Vis Sci 1991;32:594-602.|
|22||Tseng SCG, Chen JJY, Huang AJW, Kruse FE, Maskin SL, Tsai RJF. Classification of conjunctival surgeries for corneal diseases based on stem cell concept. Ophthalmol Clin North Am 1990;3:595-610.|
|23||Shimazaki J, Shinozaki N, Tsubota K. Transplantation of amniotic membrane and limbal autograft for patients with recurrent pterygium associated with symblepharon. Br J Ophthalmol 1998;82:235-40.|
|24||Yamanouchi U, Takaku I, Tsuda N, Kajiwara Y, Ueno Y. Scleromalacia presumably due to mitomycin C instillation after pterygium excision. Jpn J Clin Ophthalmol 1979;33:139-44.|
|25||Starc S, Knorr M, Steuhl KP, Rohrback JM, Thiel HJ. Autologous conjunctival-limbus transplantation in treatment of primary and recurrent pterygia. Ophthalmology 1996;93:219-33.|
|26||Broadway DC, Grierson I, Hitchings RA. Local effects of previous conjunctival incisional surgery and the subsequent outcome of filtration surgery. Am J Ophthalmol 1998;125:805-18.|
|27||Demirok A, Simsek S, Cinal A, Yasar T. Intraoperative application of mitomycin C in the surgical treatment of pterygium. Eur J Ophthalmol 1998;8:153-56.|
|28||Basti S, Mathur U. Unusual intermediate-term outcome in three cases of limbal autograft transplantation. Ophthalmology 1999;106:958-63.|
|29||Hirst CW, Sebban A, Chart D. Pterygium recurrence time. Ophthalmology 1994;101:755-58.|