Abstract
Aim
To evaluate the role of fixation in causing pterygium and determining its laterality and location.
Methods
This is a prospective, observational, case–control study. Cases were defined as patients with primary pterygium who had unilateral amblyopia with eccentric fixation. Controls were age-matched patients with primary pterygium, but without amblyopia and eccentric fixation. All patients underwent complete ocular, orthoptic, and systemic examination and a detailed risk-factor assessment (latitude of residence, exposure to sunlight, sand, and a high-reflectance environment). The role of fixation in the causation, laterality and location of pterygium was evaluated. Fisher's exact test, the unpaired t-test, and odds ratio (OR) were carried out to determine the significance of the observations.
Results
The mean age of subjects was 47.1±5.25 years in cases (n=107) and 48.2±4.75 years in controls (n=310; P=0.78). As far as known risk factors were concerned, both groups were evenly matched. Among the cases, 88 (82.2%) patients demonstrated suppression of the amblyopic eye and 19 (17.8%) patients had abnormal retinal correspondence (ARC). Patients with suppression had a unilateral pterygium in the better (fixating) eye, whereas those with ARC had bilateral pterygia. Among the controls, 192 (61.9%) eyes had bilateral pterygia and 118 (38.1%) eyes had unilateral pterygium. In controls, the dominant eye had a higher prevalence of pterygium. All patients in both groups had a nasal pterygium. Pterygium and fixation were strongly associated (P=0.007; Fisher's exact test; OR −15.98; P=0.008).
Conclusion
Fixation appears to have an important role in causing pterygium and determining its location and laterality.
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References
Foster CS, Azar DT, Dohlman CH . The Cornea: Scientific Foundations and Clinical Practice, 4th ed. Lippincott Williams and Walters: Philadelphia, PA, 2005.
Yanoff M, Duker JS . Ophthalmology, 2nd ed. Elsevier Publications: Philadelphia, PA, USA, 2008.
Buratto L, Phillipe RL, Carito G . Pterygium Surgery Chapter on. SLACK Incorporated, Thorofare Publications: New Jersey, NJ, 2000.
Saw SM, Tan D . Pterygium: prevalence, demography and risk factors. Ophthalmic Epidemiol 1999; 6: 219–228.
Reid TW, Dushku N . Does human papillomavirus cause pterygium? Br J Ophthalmol 2003; 87: 806–808.
Threlfall TJ, English DR . Sun exposure and pterygium of the eye: a dose-response curve. Am J Ophthalmol 1999; 128: 280–287.
Sekelj S, Dekaris I, Kondza-Krstonijević E, Gabrić N, Predović J, Mitrović S . Ultraviolet light and Pterygium. Coll Antropol 2007; 31 (1): 45–47.
Soliman Mahdy MA, Bhatia J . Treatment of primary pterygium: role of limbal stem cells and conjunctival autograft transplantation. Eur J Ophthalmol 2009; 19 (5): 729–732.
Coroneo MT . Pterygium as an early indicator of ultraviolet insolation. Br J Ophthalmol 1993; 77: 734–739.
Mackenzie FD, Hirst LW, Battistutta D, Green A . Risk analysis in the development of pterygia. Ophthalmol 1992; 99: 1056–1061.
Jensen OL . Pterygium, the dominant eye and the habit of closing one eye in sunlight. Acta Ophthalmol (Copenh) 1982; 60: 568–574.
Saad R . Pterygium, pinguecula and visual acuity. Aust J Ophthalmol 1977; 5 (1): 52–65.
Maloof AJ, Ho A, Coroneo MT . Influence of corneal shape on limbal light focusing. Invest Ophthalmol Vis Sci 1994; 35: 2592–2598.
Cullen AP . Anterior eye focusing of peripheral ultraviolet and visible albedo. Clin Exp Optom 1997; 80 (3): 80–86.
Noorden GK, von Campos E . Binocular Vision and Ocular Motility, 6th ed., Chapter 14. Mosby Publishers: Maryland Heights, MO, USA, 1999, pp 246–293.
Kricker A, Armstrong BK, Parkin DM . Measurement of skin cancer incidence. Health Rep 1993; 5: 63–66.
Rosenthal FS, Bakalian AE, Taylor HR . The effect of prescription eyewear on ocular exposure to ultraviolet radiation. Am J Public Health 1986; 76: 1216–1220.
Taylor HR, West SK, Rosenthal FS, Munoz B, Newland HS, Emmett EA . Corneal changes associated with chronic UV irradiation. Arch Ophthalmol 1989; 107: 1481–1484.
Landsberg HE . World Survey of Climatology. Elsevier: Amsterdam, 1984.
Ministry of New and Renewable Energy-Official Website (Government of India data). mnre.gov.in/spv-intro.htm.
Indian Institute of Sciences. CEDT. Solar irradiance. http://ecourses.vtu.ac.in/nptel/courses/Webcourse-contents/IISc-BANG/Non-Conventional%20Energy%20Systems/pdf/chap03.pdf.
Argyrous G . Statistics or Research: With a Guide to SPSS, 2nd ed. SAGE: London, 2005.
Eustace P, Wesson ME, Drury DJ . The effect of illumination on intermittent divergent squint of the divergence excess type. Trans Ophthalmol Soc UK 1973; 93: 559–570.
Wirtschafter JD, Burassa CM . Effect of increasing illumination on exodeviations. Invest Ophthalmol 1964; 3: 549.
Stidwill D . Orthoptic Assessment and Management, 2nd ed., Chapter 8.Blackwell Science: Oxford, UK, 1998, pp 140–149.
Wang Y, Liang YB, Sun LP, Duan XR, Yuan RZ, Wong TY et al Prevalence and causes of amblyopia in a rural adult population of Chinese- the Handan Eye Study. Ophthalmology 2011; 118: 279–283.
Attebo K, Mitchell P, Cumming R, Smith W, Jolly N, Sparkes R . Prevalence and causes of amblyopia in an adult population. Ophthalmol 1998; 105: 154–159.
Coroneo MT, Müller-Stolzenburg NW, Ho A . Peripheral light focusing by the anterior eye and the ophthalmohelioses. Ophthalmic Surg 1991; 22: 705–711.
Coroneo MT . Albedo concentration in the anterior eye: a phenomenon that locates some solar diseases. Ophthalmic Surg 1990; 21: 60–66.
Detorakis ET, Spandidos DA . Pathogenetic mechanisms and treatment options for ophthalmic pterygium: trends and perspectives (Review). Int J Mol Med 2009; 23: 439–447.
Chui J, Di Girolamo N, Wakefield D, Coroneo MT . The pathogenesis of pterygium; current concepts and their therapeutic implications. Ocul Surf 2008; 6: 24–43.
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Presented as a free paper at ASCRS 2011, San Diego, CA, USA.
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Sudhalkar, A. Fixation and its role in the causation, laterality and location of pterygium: a study in amblyopes and non-amblyopes. Eye 26, 438–443 (2012). https://doi.org/10.1038/eye.2011.322
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DOI: https://doi.org/10.1038/eye.2011.322
