Comparison of anterior segment parameters in normal and keratoconus eyes using combined placido-disk schiempflug imaging-based topography

Authors

DOI:

https://doi.org/10.15587/2519-4798.2022.270264

Keywords:

keratoconus, Placido-Scheimpflug imaging-based topography, anterior curvature, posterior curvature, Fleischer ring, Vogt striae, anterior stromal scar on slit-lamp examination

Abstract

The aims: The purpose of this study was to evaluate and compare the anterior and posterior corneal surface parameters, keratoconus indices, thickness profile data, and data from enhanced elevation maps of keratoconus and normal corneas using Combined Placido-Schiempflug imaging-based topography, and to determine the sensitivity and specificity of these parameters in discriminating keratoconus from normal eyes.

Materials and methods: A retrospective comparative observational study of 100 normal eyes and 100 keratoconus eyes was done from April 2014 to May 2015 at MM Joshi Eye Institute, Hubli, Karnataka. We evaluated and compared the anterior and posterior corneal surface parameters, keratoconus indices, thickness profile data, and data from enhanced elevation maps of keratoconus and normal corneas using Combined Placido-Scheimpflug Imaging based Topography to determine the sensitivity and specificity of these parameters in discriminating keratoconus from normal eyes.

Results: Keratoconus indices (Sif, Sib, BCV-f, BCV-b, KVf, KVb, CCT, MinCT) showed Excellent AUROC values followed by K- steep in posterior curvature at 3 mm, 5 mm followed by K- steep in anterior curvature and other parameters in discriminating Normal from Keratoconus-Suspect eyes. Elevation indices- BCV-f, BCV-b, CCT, Min-CT, K-steep & K-flat in anterior and posterior curvature in 3 mm, 5 mm, 7 mm, and CV were significant in discriminating normal from mild keratoconus. All parameters except ACV and ICA were significant in discriminating normal from moderate keratoconus. All parameters were significant in discriminating normal from severe keratoconus eyes. Morphological indices were significant in differentiating mild, moderate and severe keratoconus.

Conclusion: Many parameters were statistically significant between keratoconus and normal eyes compared with early keratoconus eyes.

The topography and corneal aberration results in this study are promising for detecting ectatic corneas. In our study, thickness indices-CCT, MinCT, Abberometry indices- BCVf, BCVb and keratometry in steep meridian at posterior curvature had the highest AUC scores in differentiating normal from sub-clinical keratoconus.

Elevation indices- Rbf-f, Rbf-b, thickness indices- CCT, MinCT, aberrometry indices, and keratometry-steep in anterior & posterior curvature had the highest AUC scores in differentiating moderate and severe keratoconus

Author Biographies

Madhuri Kurakula, Malla Reddy Medical College for Women

Assistant professor

Department  of Ophthalmology

Pasumarthi Pavani Yelamanchili, Maheshwara Medical College and Hospital

Assistant Professor

Department of Ophthalmology

Mannam Gitanjali, Osmania Medical College

Assistant Professor

Department of Ophthalmology

Kotagiri Srawanthy, Malla Reddy Medical College for Women

Assistant Professor

Department of Ophthalmology

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Published

2022-11-30

How to Cite

Kurakula, M., Yelamanchili, P. P., Gitanjali, M., & Srawanthy, K. (2022). Comparison of anterior segment parameters in normal and keratoconus eyes using combined placido-disk schiempflug imaging-based topography. ScienceRise: Medical Science, (6 (51), 25–40. https://doi.org/10.15587/2519-4798.2022.270264

Issue

No. 6 (51) (2022)

Section

Medical Science

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Copyright (c) 2022 Pasumarthi Pavani Yelamanchili, Madhuri Kurakula, Mannam Gitanjali, Kotagiri Srawanthy

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