Utilization of anterior segment optical coherence tomography enhanced high resolution corneal in measuring pterygium thickness

Mohd Radzi Hilmi, Khairidzan Mohd Kamal, Mohd Zulfaezal Che Azemin, Azrin Esmady Ariffin


Introduction: A significant degree of corneal astigmatism can be induced by the encroachment of a pterygium onto a cornea.  As various pterygium morphologies have been advocated as contributing factor on corneal astigmatism, little support in the literature available in establishing techniques in measuring pterygium thickness as clinical indicator. To further substantiate claims of establishing measurement of pterygium thickness, the aim of this study was to describe a quantitative method in determining pterygium thickness using anterior segment optical coherence tomography. Methods: Anterior segment imaging was performed using enhanced high resolution cornea of Visante™ optical coherence tomography in 120 primary pterygium eyes. Prior to imaging, corneal topography assessment was performed on each pterygium eye in order to identify its topographic location. Based on topography mapping, three meridians (in degrees) were selected as close as possible to the pterygium border, which signify the demarcation of pterygium from the cornea. Reliability testing between intra and inter-observer of optical coherence tomography imaging modality was examined using intraclass correlation and scatter plot. Results: The overall (n = 120) mean and standard deviation of pterygium thickness via enhanced high resolution cornea of optical coherence tomography modality were 0.48 ± 0.10 mm (confidence interval: 0.45 – 0.50). Optical coherence tomography imaging also showed excellent intra and intergrader reliability in measuring pterygium thickness with intraclass correlation of 0.997 (confidence interval: 0.994 – 0.998). Conclusions: Enhanced high resolution cornea of anterior segment optical coherence tomography imaging is a better choice in assessing pterygium compared to traditional slit-lamp biomicroscopy. This tool is applicable for future work related to better understanding on the role thickness in pterygium morphology, its progression and prediction of induced corneal astigmatism and visual impairment due to pterygium.


pterygium; anterior segment OCT; AS-OCT; morphology; thickness; reliability


Ashrafzadeh, A. & Steinert, R.F., 2009, Visante AS-OCT in evaluation of patients for refractive surgery. In: Agarwal, A., Agarwal, A and Jacob, S. eds. Refractive surgery. New Delhi, India: Jaypee Brothers Publishers, pp.52-65.

Altan-Yaycioglu, R., et al. 2013. Astigmatic changes following pterygium removal: comparison of 5 different methods, Ind J Ophthalmol, 61, pp.104–108.

Baikoff, G., et al. 2004. Static and dynamic analysis of the anterior segment with optical coherence tomography, J Cataract Refract Surg, 30, pp.1843-1850.

Buchwald, H.J., et al. 2003. Optical coherence tomography versus ultrasound biomicroscopy of conjunctival and eyelid lesion, Klin Monbl Augenheilkd, 220, pp.822–829.

Bianciotto, C, et al. 2011. Assessment of anterior segment tumors with ultrasound biomicroscopy versus anterior segment optical coherence tomography in 200 cases, Ophthalmology, 118, pp.1297–1302.

Džunic, B., et al. 2010. Analysis of pathohistological characteristics of pterygium, Bosn J Basic Med Sci, 10, pp.307–313.

Doors, M., et al. 2010. Value of optical coherence tomography for anterior segment surgery, J Cataract Refract Surg, 36, pp.1213-1229.

George, D. & Mallery, M., 2010, SPSS for Windows Step by Step, A Simple Guide and References, Boston: Pearson, 2010. 95-105p.

Goldsmith, J.A., et al. 2005. Anterior chamber width measurement by high-speed optical coherence tomography, Ophthalmology, 112, pp.238-244.

Gumus, K, et al. 2011. Effect of Pterygia on refractive Indices. Corneal Topography, and Ocular Aberrations, Cornea, 30, pp.24–29.

Kampitak, K.J. 2003. The effect of pterygium on corneal astigmatism, J Med Assoc Thai, 86, pp.16–23.

Kieval, J.Z., et al. 2012. Ultra-high resolution optical coherence tomography for differentiation of ocular surface squamous neoplasia and pterygia, Ophthalmology, 119, pp.:481-486.

Keane, P.A., et al. 2012. Evaluation of age-related macular degeneration with optical coherence tomography, Surv Ophthalmol, 57, pp.389-414.

Keane, P.A., et al. 2008. Relationship between optical coherence tomography retinal parameters and visual acuity in neovascular age-related macular degeneration, Ophthalmology, 115, pp.2206–2214.

Kheirkhah, A., et al. 2011. Evaluation of Conjunctival Graft Thickness after Pterygium Surgery by Anterior Segment Optical Coherence Tomography, Curr Eye Res, 36, pp.782-786.

Kheirkhah, A., et al. 2012. Effects of pterygium surgery on front and back corneal surfaces and anterior segment parameters, Int Ophthalmol, 32, pp.251–257.

Koo, H.C., et al. 2014. Hyperreflective foveal lesion observed with optical coherence tomography in cases of epiretinal membranes with a firm foveal attachment, Retina, 34, pp.1824-1832.

Liakopoulos, S., et al. 2008. Quantitative optical coherence tomography findings in various subtypes of neovascular age-related macular degeneration, Invest Ophthalmol Vis Sci, 49, pp.5048–5054.

Liu, T., et al. 2013. Progress in the pathogenesis of pterygium, Curr Eye Res, 38, pp.1191–1197.

Maheshwari, S. 2007. Pterygum-induced corneal refractive changes, Ind J Ophthalmol, 55, pp.383-386.

Mohammad-Salih, P.A.K. & Sharif, A.F.M.D. 2008. Analysis of Pterygium Size and Induced Corneal Astigmatism, Cornea, 27, pp.434–438.

Nanji, A.A., et al. 2015. High-resolution optical coherence tomography as an adjunctive tool in diagnosis of corneal and conjunctival pathology, Ocul Surf, 13, pp.226–235.

Oh, J.Y. & Wee, W.R. 2010. The effect of pterygium surgery on contrast sensitivity and corneal topographic changes, Clin Ophthalmol, 26, pp.315–319.

Öner, V., et al. 2016. Influence of Pterygium on Corneal Biomechanical Properties, Curr Eye Res, 41, pp.913-916.

Park, Y.M., Kim, C.D. & Lee, J.S. 2015. Effect of Bevacizumab on Human Tenon’s Fibroblasts Cultured from Primary and Recurrent Pterygium, Korean J of Physiol Pharmacol, 19, pp.357–363.

Rojas, V.D., et al. 2012. Anterior segment optical coherence tomography in corneal and conjuncticval pathology, J Emmetropia, 3, pp.177–192.

Soliman, W. & Mohamed, T.A. 2012. Spectral domain anterior segment optical coherence tomography assessment of pterygium and pinguecula, Acta Ophthalmol, 90, pp.461–465.

Tan, D.T., et al. 1997. Effect of pterygium morphology on pterygium recurrence in a controlled trial comparing conjunctival autografting with bare sclera excision, Arch Ophthalmol, 115, pp.1235–1240.

Sarac, O., Demirel, S. & Oltulu, R. 2014. Efficacy on intralesional bevacizumab administration in primary pterygium: a quantitative analysis, Eye Contact Lens, 40, pp.46–50.

Vives, P.P., et al. 2013. Topographic corneal changes in astigmatism due to pterygium’s limbal-conjunctival autograft surgery, J Emmetropia, 4, pp.13–18.

Welch, M., et al. 2011. Pterygia Measurements are more accurate with anterior segment optical coherence tomography images – a pilot study, Nepal J Ophthalmol, 3, pp.9–12.

DOI: http://dx.doi.org/10.26532/sainsmed.v9i2.2982

Article Metrics

Metrics Loading ...

Metrics powered by PLOS ALM


  • There are currently no refbacks.

Copyright (c) 2019 Sains Medika

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at http://jurnal.unissula.ac.id/index.php/sainsmedika.

stats View My Stats.