Indian Journal of Ophthalmology

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 68  |  Issue : 11  |  Page : 2415--2420

Evaluation of corneal topography and tomography in fellow eyes of unilateral keratoconus patients for early detection of subclinical keratoconus


Mithun Thulasidas, Prateek Teotia 
 Cornea, Cataract and Refractive Surgery Services, Centre for Sight Eye Institute, New Delhi, India

Correspondence Address:
Dr. Mithun Thulasidas
Centre for Sight Eye Institute, Plot No 9, Sector 9, Dwarka, New Delhi - 110 075
India

Purpose: To analyse topographic and tomographic changes in fellow eyes of unilateral keratoconus patients by comparing them with normal eyes. Methods: This five-year retrospective observational comparative case study included 15 advanced keratoconus eyes of unilateral keratoconus (KCN group), 15 normal fellow eyes of unilateral keratoconus (Fellow eye group) and 34 eyes of normal refractive surgery candidates (Normal group). Topographic and tomographic data, data from enhanced elevation maps, and keratoconus indices were measured in all study eyes using Pentacam. Receiver operating characteristic (ROC) curves were used to evaluate the area under the curve (AUC), sensitivity and specificity of each parameter and identify cut-off points in discriminating between the fellow and normal eyes. Results: Corneal thickness at the apex (CTA, P = 0.001) and at the thinnest point (CTT, P < 0.001), corneal volume (CV, P = 0.007), Belin/Ambrosio Enhanced Ectasia Display (BAD) - thinnest point (Dt, P = 0.002) and thinnest point displacement (Da, P = 0.002) were significantly lower in the fellow group compared to eyes of normal subjects. On ROC curve analysis, the most efficient distinguishing indices between the fellow group and normal controls were BAD - overall D value (AUC = 0.859), Dt (AUC =0.827), Da (AUC = 0.789) followed by pachymetric progression index maximum (AUC = 0.741). Conclusion: BAD-D value and pachymetric progression index could be useful in detecting the earliest form of subclinical keratoconus. However, every single parameter alone is not enough to detect early changes; a combination of different data is required to distinguish subclinical keratoconus.


How to cite this article:
Thulasidas M, Teotia P. Evaluation of corneal topography and tomography in fellow eyes of unilateral keratoconus patients for early detection of subclinical keratoconus.Indian J Ophthalmol 2020;68:2415-2420


How to cite this URL:
Thulasidas M, Teotia P. Evaluation of corneal topography and tomography in fellow eyes of unilateral keratoconus patients for early detection of subclinical keratoconus. Indian J Ophthalmol [serial online] 2020 [cited 2024 Mar 28 ];68:2415-2420
Available from: https://journals.lww.com/ijo/pages/default.aspx/article.asp?issn=0301-4738;year=2020;volume=68;issue=11;spage=2415;epage=2420;aulast=Thulasidas;type=0