Correlation of Corneal Topographic Parameters with Visual Acuity in Patients with Keratoconus: A Cross-Sectional Observational Study

Jawaji Soumya; P Prashanthi; Anisha Kumari Garipelli

doi:10.51168/p66zfy05

Autori

Jawaji Soumya Assistant Professor, Department of Ophthalmology, Rajiv Gandhi Institute of Medical Sciences, Adilabad, Telangana, India.
P Prashanthi Assistant Professor, Department of Ophthalmology, Rajiv Gandhi Institute of Medical Sciences, Adilabad, Telangana, India.
Anisha Kumari Garipelli Assistant Professor, Department of Ophthalmology, Rajiv Gandhi Institute of Medical Sciences, Adilabad, Telangana, India.

DOI:

https://doi.org/10.51168/p66zfy05

Cuvinte cheie:

Keratoconus, Corneal topography, Visual acuity, Kmax, Pachymetry, Corneal astigmatism, Cross-sectional study

Rezumat

Background

Keratoconus is a progressive corneal ectatic disorder characterized by thinning, steepening, irregular astigmatism, and reduced visual acuity. Corneal topography provides quantitative indices for assessing structural severity and functional impact.

Objectives

To assess the correlation of corneal topographic parameters with best-corrected visual acuity (BCVA) in patients with keratoconus

Methods

This hospital-based cross-sectional observational study included 100 consecutively enrolled patients with keratoconus at Rajiv Gandhi Institute of Medical Sciences, Adilabad, from August 2025 to January 2026. One eye per patient was analysed. BCVA was recorded in logMAR units. Keratometric, pachymetric, astigmatic, and elevation parameters were assessed by corneal topography. Pearson correlation analysis evaluated associations with BCVA.

Results

Mean age was 23.6 ± 6.8 years; 58.0% were male. Mild, moderate, and severe keratoconus accounted for 26.0%, 44.0%, and 30.0%, respectively. Mean BCVA was 0.42 ± 0.28 logMAR, Kmax 56.9 ± 8.4 D, and thinnest pachymetry 439.5 ± 46.2 µm. BCVA worsened from 0.18 ± 0.10 logMAR in mild disease to 0.68 ± 0.27 logMAR in severe disease (p < 0.001). Kmax had the strongest positive correlation with BCVA (r = 0.71, p < 0.001), whereas thinnest pachymetry had the strongest negative correlation (r = −0.66, p < 0.001). K2 (r = 0.64), posterior elevation (r = 0.62), anterior elevation (r = 0.57), central corneal thickness (r = −0.54), K1 (r = 0.52), and corneal astigmatism (r = 0.48) were also significant (all p < 0.001).

Conclusion

Greater corneal steepening and thinning were significantly associated with poorer BCVA. Kmax and thinnest pachymetry showed the strongest correlations and may serve as useful structural indicators during assessment and follow-up.

Recommendations

Routine topographic monitoring, particularly Kmax and pachymetry, should support severity grading, follow-up, visual rehabilitation, and timely referral for cross-linking when clinically indicated.

Biografii autori

Jawaji Soumya, Assistant Professor, Department of Ophthalmology, Rajiv Gandhi Institute of Medical Sciences, Adilabad, Telangana, India.

Dr. Soumya Jawaji is an Assistant Professor in the Department of Ophthalmology at Rajiv Gandhi Institute of Medical Sciences, Adilabad, Telangana, India. She completed her MBBS from Osmania Medical College during 2010–2016 and obtained her M.S. Ophthalmology from Kakatiya Medical College during 2018–2021. She completed her senior residency at RIMS, Adilabad, during 2021–2022. Her academic interests include clinical ophthalmology, corneal disorders, retinal diseases, and imaging-based evaluation of anterior and posterior segment conditions. ORCID iD: https://orcid.org/0009-0007-7693-0078
P Prashanthi, Assistant Professor, Department of Ophthalmology, Rajiv Gandhi Institute of Medical Sciences, Adilabad, Telangana, India.

Dr. Prashanthi P. is an Assistant Professor in the Department of Ophthalmology at Rajiv Gandhi Institute of Medical Sciences, Adilabad, Telangana, India. She completed her MBBS from Pratima Institute of Medical Sciences during 2009–2014 and completed DNB Ophthalmology from GMERS Medical College during 2016–2019. She also completed a Fellowship in Cornea and Microsurgery at Aravind Eye Hospital, Chennai, during 2021–2023. She served as Senior Resident at ESIC Medical College, Hyderabad, during 2023–2024. Her academic interests include cornea, microsurgery, corneal imaging, and clinical ophthalmic research. ORCID iD: https://orcid.org/0009-0003-5462-0512
Anisha Kumari Garipelli, Assistant Professor, Department of Ophthalmology, Rajiv Gandhi Institute of Medical Sciences, Adilabad, Telangana, India.

Dr. Anisha Kumari Garipelli is an Assistant Professor in the Department of Ophthalmology at Rajiv Gandhi Institute of Medical Sciences, Adilabad, Telangana, India. She completed her MBBS from Alluri Sita Rama Raju Academy of Medical Sciences during 2008–2013 and completed DNB Ophthalmology from Pushpagiri Eye Institute, Secunderabad, during 2015–2018. She served as Senior Resident at Ulhas Patil Medical College, Jalgaon, in 2019 and later at RIMS, Adilabad, from 2019–2021. Her academic interests include comprehensive ophthalmology, retinal evaluation, corneal evaluation, and clinical teaching. ORCID iD: https://orcid.org/0009-0009-7062-9932

Referințe

1. Rabinowitz YS. Keratoconus. Surv Ophthalmol. 1998 Jan-Feb;42(4):297-319. doi:10.1016/S0039-6257(97)00119-7. PMID: 9493273.

2. Romero-Jiménez M, Santodomingo-Rubido J, Wolffsohn JS. Keratoconus: a review. Cont Lens Anterior Eye. 2010 Aug;33(4):157-166; quiz 205. doi:10.1016/j.clae.2010.04.006. PMID: 20537579.

3. Gomes JAP, Tan D, Rapuano CJ, Belin MW, Ambrósio R Jr, Guell JL, et al. Global consensus on keratoconus and ectatic diseases. Cornea. 2015 Apr;34(4):359-369. doi:10.1097/ICO.0000000000000408. PMID: 25738235.

4. Mas Tur V, MacGregor C, Jayaswal R, O'Brart D, Maycock N. A review of keratoconus: diagnosis, pathophysiology, and genetics. Surv Ophthalmol. 2017 Nov-Dec;62(6):770-783. doi:10.1016/j.survophthal.2017.06.009. PMID: 28688894.

5. Hashemi H, Heydarian S, Hooshmand E, Saatchi M, Yekta A, Aghamirsalim M, et al. The prevalence and risk factors for keratoconus: a systematic review and meta-analysis. Cornea. 2020 Feb;39(2):263-270. doi:10.1097/ICO.0000000000002150. PMID: 31498247.

6. Godefrooij DA, de Wit GA, Uiterwaal CS, Imhof SM, Wisse RPL. Age-specific incidence and prevalence of keratoconus: a nationwide registration study. Am J Ophthalmol. 2017 Mar;175:169-172. doi:10.1016/j.ajo.2016.12.015. PMID: 28039037.

7. Belin MW, Duncan JK. Keratoconus: The ABCD Grading System. Klin Monbl Augenheilkd. 2016 Jun;233(6):701-707. doi:10.1055/s-0042-100626. PMID: 26789119.

8. Zadnik K, Barr JT, Edrington TB, Everett DF, Jameson M, McMahon TT, et al. Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci. 1998 Dec;39(13):2537-2546. PMID: 9856763.

9. Wagner H, Barr JT, Zadnik K; Collaborative Longitudinal Evaluation of Keratoconus Study Group. Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study: methods and findings to date. Cont Lens Anterior Eye. 2007 Sep;30(4):223-232. doi:10.1016/j.clae.2007.03.001. PMID: 17481941.

10. Davis LJ, Schechtman KB, Wilson BS, Rosenstiel CE, Riley CH, Libassi DP, et al. Longitudinal changes in visual acuity in keratoconus. Invest Ophthalmol Vis Sci. 2006 Feb;47(2):489-500. doi:10.1167/iovs.05-0817. PMID: 16431941.

11. McMahon TT, Edrington TB, Szczotka-Flynn L, Olafsson HE, Davis LJ, Schechtman KB. Longitudinal changes in corneal curvature in keratoconus. Cornea. 2006 Apr;25(3):296-305. PMID: 16633030.

12. Bayraktar Bilen N, Hepsen IF, Arce CG. Correlation between visual function and refractive, topographic, pachymetric and aberrometric data in eyes with keratoconus. Int J Ophthalmol. 2016 Aug 18;9(8):1127-1133. doi:10.18240/ijo.2016.08.07. PMID: 27588266.

13. Piñero DP, Alió JL, Alesón A, Vergara ME, Miranda M. Corneal volume, pachymetry, and correlation of anterior and posterior corneal shape in subclinical and different stages of clinical keratoconus. J Cataract Refract Surg. 2010 May;36(5):814-825. doi:10.1016/j.jcrs.2009.11.012. PMID: 20457375.

14. Alió JL, Shabayek MH. Corneal higher order aberrations: a method to grade keratoconus. J Refract Surg. 2006 Jun;22(6):539-545. doi:10.3928/1081-597X-20060601-05. PMID: 16805116.