International Journal of Keratoconus and Ectatic Corneal Diseases

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VOLUME 1 , ISSUE 3 ( September-December, 2012 ) > List of Articles

RESEARCH ARTICLE

Correlation of Topometric and Tomographic Indices with Visual Acuity in Patients with Keratoconus

Isaac C Ramos, Bernardo T Lopes, Fernando Faria-Correia, Bruno de Freitas Valbon, Michael Wellington Belin, Renato Ambrósio

Citation Information : Ramos IC, Lopes BT, Faria-Correia F, Valbon BD, Belin MW, Ambrósio R. Correlation of Topometric and Tomographic Indices with Visual Acuity in Patients with Keratoconus. Int J Kerat Ect Cor Dis 2012; 1 (3):167-172.

DOI: 10.5005/jp-journals-10025-1032

Published Online: 01-08-2015

Copyright Statement:  Copyright © 2012; The Author(s).


Abstract

Purpose

To evaluate the correlations of Pentacam keratometric, topometric (derived from front surface curvature) and tomographic (derived from 3D corneal shape analysis) indices with best corrected visual acuity in patients with keratoconus.

Materials and methods

One eye randomly selected of 123 patients with bilateral keratoconus was retrospectively enrolled. All patients underwent a comprehensive ophthalmic examination including subjective refraction, distance best-spectacle corrected visual acuity (DCVA) measurement, and rotating Scheimpflug corneal tomography (Pentacam HR; Oculus, Wetzlar, Germany) at the same office visit. The correlations between the logarithm of the minimum angle of resolution (LogMAR) of DCVA and keratometric indices, topometric indices and tomographic indices were tested with nonparametric Spearman correlation coefficients (?).

Results

The mean LogMAR DCVA was 0.32 (~20/42) ±0.27 [range: −0.10 (20/15) to 1.30 (20/400)]. There were strong correlations between DCVA and many keratometric, topometric and tomographic indices. A strong positive correlation was found between DCVA and BAD-Df (ρ = 0.648, p < 0.001), BAD-Db (ρ = 0.633, p < 0.001), K2 (ρ = 0.643, p < 0.001), Kmax (ρ = 0.608, p < 0.001), TKC (ρ = 0.558, p < 0.001), BAD-D (ρ = 0.577, p < 0.001), ISV (ρ = 0.573, p < 0.001), CKI (ρ = 0.530, p < 0.001), KI (ρ = 0.531, p < 0.001). A strong negative correlation was seen between DCVA and Asph Q front 30° (ρ = −0.521, p < 0.001).

Conclusion

There are significant correlations between visual acuity and Pentacam parameters. Such parameters may be considered for improving staging of the disease, as well as for monitoring progression or treatment as outcome measures. There is a potential for combining parameters to enhance the correlations.

How to cite this article

Lopes BT, Ramos IC, Faria-Correia F, Luz A, de Freitas Valbon B, Belin MW, Ambrósio R Jr. Correlation of Topometric and Tomographic Indices with Visual Acuity in Patients with Keratoconus. Int J Kerat Ect Cor Dis 2012;1(3):167-172.

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  1. Keratoconus and related noninflammatory corneal thinning disorders. Surv Ophthalmol 1984;28(4):293-322.
  2. Keratoconus. Surv Ophthalmol 1998;42(4):297-319.
  3. Prognostic factors for the progression of keratoconus. Ophthalmology 1994;101(3):439-47.
  4. Wavefront aberrations measured with Hartmann-Shack sensor in patients with keratoconus. Ophthalmology 2002;109(11):1996-2003.
  5. The true inventors of the keratoscope and photo- keratoscope. Br J Hist Sci 1965;2(8):324-42.
  6. Use of a support vector machine for keratoconus and subclinical keratoconus detection by topographic and tomographic data. Ophthalmology 2012;119(11):2231-38.
  7. Computer-assisted corneal topography. High- resolution graphic presentation and analysis of keratoscopy. Invest Ophthalmol Vis Sci 1984;25(12):1426-35.
  8. Standardized color-coded maps for corneal topography. Ophthalmology 1993;100(11): 1723-27.
  9. Computer-assisted corneal topography in keratoconus. Refract Corneal Surg 1989;5(6): 400-08.
  10. Corneal topography of keratoconus. Cornea 1991;10(1):2-8.
  11. Quantitative descriptors of corneal topography. A clinical study. Archiv Ophthalmol 1991;109(3): 349-53.
  12. A reliable corneal tomography system is still needed. Ophthalmology 2003;110(3):455-56.
  13. Imaging of the cornea: Topography vs tomography. J Refract Surg 2010;26(11):847-49.
  14. New technology in corneal imaging. Int Ophthalmol Clin 2010;50(3):177-89.
  15. Advances in anterior segment imaging and analysis. Curr Opin Ophthalmol 2009;20(4):324-32.
  16. Central and peripheral corneal thinning in keratoconus. Cornea 2012 May 3. [Epub ahead of print].
  17. Repeatability and reproducibility of pachymetric mapping with Visante anterior segment—optical coherence tomography. Invest Ophthalmol Vis Sci 2007;48(12):5499-504.
  18. A comprehensive evaluation of the precision (repeatability and reproducibility) of the Oculus Pentacam HR. Invest Ophthalmol Vis Sci 2011;52(10):7731-37.
  19. Quality of life in keratoconus. Am J Ophthalmol 2004;138(4):527-35.
  20. Changes in the quality-of-life of people with keratoconus. Am J Ophthalmol 2008;145(4):611-17.
  21. Visual functions and quality of life in patients with keratoconus. Cesk Slov Oftalmol 2011;67(2):51-54.
  22. Mechanism of aberration balance and the effect on retinal image quality in keratoconus: Optical and visual characteristics of keratoconus. J Cataract Refract Surg 2011;37(5):914-22.
  23. Baseline findings in the collaborative longitudinal evaluation of keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci 1998;39(13):2537-46.
  24. Videokeratographic indices to aid in screening for keratoconus. J Refract Surg 1995;11(5):371-79.
  25. Keratoconus: Classification scheme based on videokeratography and clinical signs. J Cataract Refract Surg 2009;35(9):1597-603.
  26. Live-epikeratophakia for keratoconus. J Cataract Refract Surg 1998;24(4):456-63.
  27. , Caiado AL, Guerra FP, Louzada R, Roy AS, Luz A, et al. Novel pachymetric parameters based on corneal tomography for diagnosing keratoconus. J Refract Surg 2011;27(10):753-58.
  28. Circular keratotomy to reduce astigmatism and improve vision in stage I and II keratoconus. J Refract Surg 2009;25(4):357-65.
  29. Topometric and tomographic indices for the diagnosis of keratoconus. Int J Kerat Ect Cor Dis 2012;1(2):92-99.
  30. Ferrara intrastromal corneal rings for the correction of keratoconus. J Cataract Refract Surg 2002;28(11):1947-51.
  31. Correcting keratoconus with intracorneal rings. J Cataract Refract Surg 2000;26(8): 1117-22.
  32. Long-term follow-up of intrastromal corneal ring segments in keratoconus. J Cataract Refract Surg 2009;35(10):1768-73.
  33. Riboflavin/ultraviolet-a- induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol 2003;135(5):620-27.
  34. Flattening of the cornea after collagen crosslinking for keratoconus. J Cataract Refract Surg 2011;37(8):1488-92.
  35. Comparison of sequential vs same-day simultaneous collagen cross-linking and topography-guided PRK for treatment of keratoconus. J Refract Surg 2009;25(9):S812-18.
  36. Prediction of letter contrast sensitivity using video- keratographic indices. Am J Ophthalmol 2000;129(6):759-63.
  37. A new method for grading the severity of keratoconus: The keratoconus severity score (KSS). Cornea 2006;25(7):794-800.
  38. Keratoconus-integrated characterization considering anterior corneal aberrations, internal astigmatism, and corneal biomechanics. J Cataract Refract Surg 2011;37(3):552-68.
  39. Correlation of corneal elevation with severity of keratoconus by means of anterior and posterior topographic analysis. Cornea 2012 Mar;31(3):253-58.
  40. Correlation of anterior segment parameters in keratoconus patients. Int J Kerat Ect Cor Dis 2012;1(2):87-91.
  41. The challenges of the detection of subclinical keratoconus at its earliest stage. Int J Keratoco Ectatic Corneal Dis 2012;1(1):36-43.
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