- Deborah S Jacobs, MD
Deborah S Jacobs, MD
- Associate Professor of Ophthalmology, Part-Time
- Harvard Medical School
A pterygium is a triangular wedge of fibrovascular conjunctival tissue that typically starts medially on the nasal conjunctiva and extends laterally onto the cornea (picture 1). "Pterygium" refers to the shape of the tissue, which looks like an insect wing. The plural form of pterygium is pterygia.
A pterygium is sometimes thought of as a trivial problem because it is unlikely to threaten visual acuity unless it approaches the visual axis. Nevertheless, it can be a cause of concern to patients because of the abnormal appearance it confers upon the eye and the irritation that is often associated with it. Although benign in the sense that pterygium is not cancerous, it can have important adverse effects on vision if proliferation approaches or reaches the visual axis.
This topic will focus on the clinical presentation, diagnosis, and treatment of pterygium. Some conditions that may occasionally be confused with pterygium are discussed in detail elsewhere. (See "Conjunctivitis" and "Blepharitis" and "Episcleritis" and "Photokeratitis".)
Worldwide prevalence of pterygium varies from 1 to 25 percent, depending on the population studied [1-6]. Pterygium occurs more commonly in tropical regions, although the exact mechanisms for this are not well known [7-9]. The prevalence of pterygium is associated with chronic sun exposure  and specifically to ultraviolet (UV) light [11-13], which may partly explain the geographic variation in prevalence.
Several population-based studies have found higher rates of pterygium to be associated with older age, male sex, fewer years of education, and outdoor job location [2,6,14-16]. In the Barbados Eye Study, approximately one-fourth of the black participants had pterygium, a frequency that was 2.5 to 3 times higher than among whites in this study . Among black participants, lower rates of pterygium were associated with darker skin complexion. Lower rates were also associated with always using sunglasses outdoors and using prescription glasses [1,16]. One study in Australia found a higher rate of pterygium in rural areas compared with urban areas (6.7 and 1.7 percent, respectively), partly as a result of ocular sun exposure .To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:
- Luthra R, Nemesure BB, Wu SY, et al. Frequency and risk factors for pterygium in the Barbados Eye Study. Arch Ophthalmol 2001; 119:1827.
- Cajucom-Uy H, Tong L, Wong TY, et al. The prevalence of and risk factors for pterygium in an urban Malay population: the Singapore Malay Eye Study (SiMES). Br J Ophthalmol 2010; 94:977.
- West S, Muñoz B. Prevalence of pterygium in Latinos: Proyecto VER. Br J Ophthalmol 2009; 93:1287.
- Viso E, Gude F, Rodríguez-Ares MT. Prevalence of pinguecula and pterygium in a general population in Spain. Eye (Lond) 2011; 25:350.
- Fotouhi A, Hashemi H, Khabazkhoob M, Mohammad K. Prevalence and risk factors of pterygium and pinguecula: the Tehran Eye Study. Eye (Lond) 2009; 23:1125.
- Ma K, Xu L, Jie Y, Jonas JB. Prevalence of and factors associated with pterygium in adult Chinese: the Beijing Eye Study. Cornea 2007; 26:1184.
- Anderson JR. A pterygium map. Acta Ophthalmol 1954; 3:1631.
- Singh G. Pterygium in the tropics. Ophthalmology 1990; 97:542.
- Wiwanitkit V. Tropical pterygium. Bull Soc Belge Ophtalmol 2009; :7.
- Threlfall TJ, English DR. Sun exposure and pterygium of the eye: a dose-response curve. Am J Ophthalmol 1999; 128:280.
- Mackenzie FD, Hirst LW, Battistutta D, Green A. Risk analysis in the development of pterygia. Ophthalmology 1992; 99:1056.
- Bradley JC, Yang W, Bradley RH, et al. The science of pterygia. Br J Ophthalmol 2010; 94:815.
- Liang QF, Xu L, Jin XY, et al. Epidemiology of pterygium in aged rural population of Beijing, China. Chin Med J (Engl) 2010; 123:1699.
- Wong TY, Foster PJ, Johnson GJ, et al. The prevalence and risk factors for pterygium in an adult Chinese population in Singapore: the Tanjong Pagar survey. Am J Ophthalmol 2001; 131:176.
- McCarty CA, Fu CL, Taylor HR. Epidemiology of pterygium in Victoria, Australia. Br J Ophthalmol 2000; 84:289.
- Nemesure B, Wu SY, Hennis A, et al. Nine-year incidence and risk factors for pterygium in the barbados eye studies. Ophthalmology 2008; 115:2153.
- Tan DT, Lim AS, Goh HS, Smith DR. Abnormal expression of the p53 tumor suppressor gene in the conjunctiva of patients with pterygium. Am J Ophthalmol 1997; 123:404.
- Aspiotis M, Tsanou E, Gorezis S, et al. Angiogenesis in pterygium: study of microvessel density, vascular endothelial growth factor, and thrombospondin-1. Eye (Lond) 2007; 21:1095.
- Piras F, Moore PS, Ugalde J, et al. Detection of human papillomavirus DNA in pterygia from different geographical regions. Br J Ophthalmol 2003; 87:864.
- Tsironi S, Ioachim E, Machera M, et al. Immunohistochemical HLA-DR antigen expression with lymphocyte subsets and proliferative activity in pterygium. In Vivo 2002; 16:299.
- Solomon AS. Pterygium. Br J Ophthalmol 2006; 90:665.
- Tsai YY, Cheng YW, Lee H, et al. Oxidative DNA damage in pterygium. Mol Vis 2005; 11:71.
- Kwok LS, Coroneo MT. A model for pterygium formation. Cornea 1994; 13:219.
- Fong KS, Balakrishnan V, Chee SP, Tan DT. Refractive change following pterygium surgery. CLAO J 1998; 24:115.
- Lin A, Stern G. Correlation between pterygium size and induced corneal astigmatism. Cornea 1998; 17:28.
- Todani A, Melki SA. Pterygium: current concepts in pathogenesis and treatment. Int Ophthalmol Clin 2009; 49:21.
- Hoffman RS, Power WJ. Current options in pterygium management. Int Ophthalmol Clin 1999; 39:15.
- Frucht-Pery J, Siganos CS, Solomon A, et al. Topical indomethacin solution versus dexamethasone solution for treatment of inflamed pterygium and pinguecula: a prospective randomized clinical study. Am J Ophthalmol 1999; 127:148.
- Frucht-Pery J, Solomon A, Siganos CS, et al. Treatment of inflamed pterygium and pinguecula with topical indomethacin 0.1% solution. Cornea 1997; 16:42.
- Hosseini H, Nejabat M, Khalili MR. Bevacizumab (Avastin) as a potential novel adjunct in the management of pterygia. Med Hypotheses 2007; 69:925.
- Fallah Tafti MR, Khosravifard K, Mohammadpour M, et al. Efficacy of intralesional bevacizumab injection in decreasing pterygium size. Cornea 2011; 30:127.
- Saxena S, Vishwkarma K, Khattri M, Kishore P. Multiple subconjunctival bevacizumab for advanced primary pterygium. Ann Ophthalmol (Skokie) 2010; 42 Spec No:28.
- Mandalos A, Tsakpinis D, Karayannopoulou G, et al. The effect of subconjunctival ranibizumab on primary pterygium: a pilot study. Cornea 2010; 29:1373.
- Hirst LW. The treatment of pterygium. Surv Ophthalmol 2003; 48:145.
- Ang LP, Chua JL, Tan DT. Current concepts and techniques in pterygium treatment. Curr Opin Ophthalmol 2007; 18:308.
- Chen PP, Ariyasu RG, Kaza V, et al. A randomized trial comparing mitomycin C and conjunctival autograft after excision of primary pterygium. Am J Ophthalmol 1995; 120:151.
- Sánchez-Thorin JC, Rocha G, Yelin JB. Meta-analysis on the recurrence rates after bare sclera resection with and without mitomycin C use and conjunctival autograft placement in surgery for primary pterygium. Br J Ophthalmol 1998; 82:661.
- Küçükerdönmez C, Akova YA, Altinörs DD. Comparison of conjunctival autograft with amniotic membrane transplantation for pterygium surgery: surgical and cosmetic outcome. Cornea 2007; 26:407.
- Luanratanakorn P, Ratanapakorn T, Suwan-Apichon O, Chuck RS. Randomised controlled study of conjunctival autograft versus amniotic membrane graft in pterygium excision. Br J Ophthalmol 2006; 90:1476.
- Amano S, Motoyama Y, Oshika T, et al. Comparative study of intraoperative mitomycin C and beta irradiation in pterygium surgery. Br J Ophthalmol 2000; 84:618.
- Jürgenliemk-Schulz IM, Hartman LJ, Roesink JM, et al. Prevention of pterygium recurrence by postoperative single-dose beta-irradiation: a prospective randomized clinical double-blind trial. Int J Radiat Oncol Biol Phys 2004; 59:1138.
- Yalcin Tok O, Burcu Nurozler A, Ergun G, et al. Topical cyclosporine A in the prevention of pterygium recurrence. Ophthalmologica 2008; 222:391.
- Khakshoor H, Razavi ME, Daneshvar R, et al. Preoperative subpterygeal injection vs intraoperative mitomycin C for pterygium removal: comparison of results and complications. Am J Ophthalmol 2010; 150:193.
- Sodhi PK, Verma L, Pandey RM, Ratan S. Comparison between the role of intraoperative mitomycin C and doxorubicin in preventing the recurrence of primary pterygium. Ophthalmic Res 2005; 37:1.
- Dadeya S, Kamlesh . Intraoperative daunorubicin to prevent the recurrence of pterygium after excision. Cornea 2001; 20:172.
- Bekibele CO, Baiyeroju AM, Olusanya BA, et al. Pterygium treatment using 5-FU as adjuvant treatment compared to conjunctiva autograft. Eye (Lond) 2008; 22:31.
- Pan HW, Zhong JX, Jing CX. Comparison of fibrin glue versus suture for conjunctival autografting in pterygium surgery: a meta-analysis. Ophthalmology 2011; 118:1049.
- Solomon A, Pires RT, Tseng SC. Amniotic membrane transplantation after extensive removal of primary and recurrent pterygia. Ophthalmology 2001; 108:449.
- Hirst LW, Sebban A, Chant D. Pterygium recurrence time. Ophthalmology 1994; 101:755.
- Lu P, Chen X, Kang Y, et al. Pterygium in Tibetans: a population-based study in China. Clin Exp Ophthalmol 2007; 35:828.
- Al-Bdour M, Al-Latayfeh MM. Risk factors for pterygium in an adult Jordanian population. Acta Ophthalmol Scand 2004; 82:64.