Skip to main content

Corneal tomography and biomechanics in primary pterygium

International Ophthalmology volume 38, pages 663–671 (2018)Cite this article

Abstract

Purpose

To study the Scheimpflug’s imaging and corneal biomechanics in primary pterygium.

Methods

A prospective observational study of 55 patients with unilateral primary nasal pterygium was done. The normal fellow eyes of patients with pterygium were taken as controls. Clinical parameters noted included visual acuity, values of corneal curvature by doing Scheimpflug imaging, wavefront aberrations in terms of higher and lower-order aberrations and corneal hysteresis (CH) as well as corneal resistance factor (CRF) values by using ocular response analyzer.

Results

Of the total 55 patients, mean age was 43.0 + 11.4 years (range: 20–72 years). Mean LogMar uncorrected visual acuity in pterygium eyes and control eyes was 0.21 + 0.20 and 0.12 + 0.15, respectively (p = 0.016). On Scheimpflug imaging the mean anterior corneal curvature values (Ka1/Ka2 D) were 41.09 + 3.38/44.33 + 2.29 in pterygium eyes, 43.13 + 1.79/43.98 + 2.17 in control eyes (p < 0.0005) and mean posterior corneal curvature (Kp1/Kp2 D) values were 6.14 + 0.39/6.53 + 0.43 in pterygium eyes and 6.13 + 0.28/6.46 + 0.47 in control eyes (p > 0.05). Analysis of corneal aberrations showed significantly higher corneal wavefront aberrations in pterygium eyes. Highest correlation of corneal astigmatism was noted with corneal area encroached by pterygium (ρ = 0.540 for LOA and 0.553 for HOA) and distance from pupillary center (ρ = 0.531 for LOA and 0.564 for HOA). Corneal biomechanical parameters including CH and CRF were found to be lower in the pterygium eyes, though not statistically significant (p value 0.60 and 0.59, respectively).

Conclusion

Pterygium leads to deterioration of visual performance not only by causing refractive and topographic changes but also by causing a significant increase in corneal wavefront aberrations.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

43,34 €

Price includes VAT (Finland)
Tax calculation will be finalised during checkout.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

References

  1. Johnson GJ, Minassian DC, Weale RA, West SK (2003) Pterygium. In: Epidemiology of eye disease, 2nd edn. Arnold Publishers, London

  2. Sihota R, Tandon R (2014) Diseases of the conjunctiva. In: Parson’s diseases of the eye, 22nd edn. Elsevier, New Delhi, pp 184–185

  3. Moran DJ, Hollows FC (1984) Pterygium and ultraviolet radiation: a positive correlation. Br J Ophthalmol 68:343–346

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  4. Gazzard G, Saw SM, Farook M, Koh D, Widjaja D, Chia SE, Hong CY, Tan DT (2002) Pterygium in Indonesia: prevalence, severity and risk factors. Br J Ophthalmol 86:1341–1346

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  5. Threlfall TJ, English DR (1999) Sun exposure and pterygium of the eye: a dose-response curve. Am J Ophthalmol 128:280–287

    CAS  Article  PubMed  Google Scholar 

  6. Beden U, Irkeç M, Orhan D, Orhan M (2003) The roles of T-lymphocyte subpopulations (CD4 and CD8), intercellular adhesion molecule-1 (ICAM-1), HLA-DR receptor and mast cells in etiopathogenesis of pterygium. Ocul Immunol Inflamm 11:115–122

    CAS  Article  PubMed  Google Scholar 

  7. Chui J, Di Girolamo N, Coroneo MT, Wakefield D (2007) The role of substance P in the pathogenesis of pterygia. Invest Ophthalmol Vis Sci 48:4482–4489

    Article  PubMed  Google Scholar 

  8. Dushku N, Reid TW (1994) Immunohistochemical evidence that human pterygia originate from an invasion of vimentin-expressing altered limbal epithelial basal cells. Curr Eye Res 13:473–481

    CAS  Article  PubMed  Google Scholar 

  9. Duke-Elder SS (ed) (1993) Degenerative and pigmentary changes. In: System of ophthalmology. London: Henry Kimpton

  10. Waller SG, Adamis AP (1994) Pterygium. In: Tasman W, Jaeger EA (eds) Duane’s clinical of ophthalmology. JB Lippincott, Philadelphia

    Google Scholar 

  11. Hochbaum DR, Moskowitz SE, Wirtschafter JD (1977) A quantitative analysis of astigmatism induced by pterygium. J Biomech 10:735–746

    CAS  Article  PubMed  Google Scholar 

  12. Yasar T, Ozdemir M, Cinal A et al (2003) Effects of fibrovascular membrane and pooling of tears on corneal topographic changes induced by induced by pterygium. Eye 7:492–496

    Article  Google Scholar 

  13. Prisant O et al (2002) Vector summation of anterior and posterior corneal topographical astigmatism. JCRS 28:1636–1643

    Google Scholar 

  14. Tanabe T, Tomidokoro A, Samejima T et al (2004) Corneal regular and irregular astigmatism assessed by Fourier analysis of videokeratography data in normal and pathological eyes. Ophthalmology 111:752–757

    Article  PubMed  Google Scholar 

  15. Saw SM, Tan D (1999) Pterygium: prevalence, demography and risk factors. Ophthalmic Epidemiol 6:219–228

    CAS  Article  PubMed  Google Scholar 

  16. Dubbelman M, Sicam VA, der HeijdeGL Van (2006) The shape of the anterior and posterior surface of the aging human cornea. Vis Res 46:993–1001

    CAS  Article  PubMed  Google Scholar 

  17. Dunne MC, Royston JM, Barnes DA (1991) Posterior corneal surface toricity and total corneal astigmatism. Optom Vis Sci 68:708–710

    CAS  Article  PubMed  Google Scholar 

  18. Mootha VV, Pingree M, Jaramillo J (2004) Pterygia with deep corneal changes. Cornea 23:635–638

    Article  PubMed  Google Scholar 

  19. McCarty CA, Fu CL, Taylor HR (2000) Epidemiology of pterygium in Victoria, Australia. Br J Ophthalmol 84:289–292

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  20. Lindsay RG, Sullivan L (2001) Pterygium-induced corneal astigmatism. Clin Exp Optom 84:200–203

    Article  PubMed  Google Scholar 

  21. Kheirkhah A, Safi H, Molaei S, Nazari R, Behrouz MJ, Raju VK (2012) Effects of pterygium surgery on front and back corneal astigmatism. Can J Ophthalmol 47:423–428

    Article  PubMed  Google Scholar 

  22. Hansen A, Norn M (1980) Astigmatism and surface phenomena in pterygium. Acta Ophthalmol 58:174–181

    CAS  Article  Google Scholar 

  23. Ozdemir M, Cinal A (2005) Early and late effects of pterygium surgery on corneal topography. Ophthalmic Surg Lasers Imaging 36:451–456

    PubMed  Google Scholar 

  24. Tomidokoro A, Oshika T, Amano S, Eguchi K, Eguchi S (1999) Quantitative analysis of regular and irregular astigmatism induced by pterygium. Cornea 18:412–415

    CAS  Article  PubMed  Google Scholar 

  25. Zare M, Zarei-Ghanavati S, Ansari-Astaneh MR, Baradaran-Rafiee A, Einolahi B (2010) Effects of pterygium on ocular aberrations. Cornea 29:1232–1235

    PubMed  Google Scholar 

  26. Pesudovs K, Figueiredo FC (2006) Corneal first surface wavefront aberrations before and after pterygium surgery. J Refract Surg 22:921–925

    PubMed  Google Scholar 

  27. Oner V, Taş M, Ozkaya E, Bulut A (2016) Influence of pterygium on corneal biomechanical properties. Curr Eye Res 41:913–916

    Article  PubMed  Google Scholar 

Download references

Author information

Affiliations

  1. Cornea, Cataract and Refractive Services, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, 110029, India

    M. Vanathi, Sahil Goel, Anita Ganger, Tushar Agarwal, T. Dada & Sudarshan Khokhar

Authors
  1. M. Vanathi
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Sahil Goel
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Anita Ganger
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Tushar Agarwal
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. T. Dada
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Sudarshan Khokhar
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to M. Vanathi.

Ethics declarations

Conflict of interest

There are no conflict of interests and financial disclosures to be made.

Ethical approval

All procedures performed in this study were in accordance with the ethical standards of the institutional research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. This study was approved by the Institute Ethical Committee of AIIMS.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Vanathi, M., Goel, S., Ganger, A. et al. Corneal tomography and biomechanics in primary pterygium. Int Ophthalmol 38, 663–671 (2018). https://doi.org/10.1007/s10792-017-0514-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10792-017-0514-6

Keywords

  • Pterygium
  • Visual acuity
  • Corneal topography
  • Wavefront aberrations
  • Biomechanics