Application of high resolution OCT to evaluate irregularity of Bowman's layer in asymmetric keratoconus

Natasha Pahuja, Rushad Shroff, Pratik Pahanpate, Mathew Francis, Leio Veeboy, Rohit Shetty, Rudy M. M. A. Nuijts, Abhijit Sinha Roy*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

11 Citations (Web of Science)

Abstract

Irregularity of the Bowman's layer (BL) in keratoconus (KC, sample size (n) = 28) and forme fruste keratoconus (FFKC, n = 18) eyes was evaluated. Subjects underwent high resolution OCT imaging (Bioptigen Inc., USA) and corneal tomography (Pentacam v1.20r41, OCULUS Optikgerate GmbH, Germany). Anterior edge of the BL was segmented. A Bowman's roughness index (BRI) was defined as the sum of the enclosed areas between segmented edge and a smooth 3(rd) order polynomial fit to the edge. BRI was compared with corneal aberrations, Keratoconus percentage index (KISA), Cone location magnitude index (CLMI) and Belin-Ambrosio enhanced ectasia display overall deviation index (BAD-D). Area under the curve (AUC) was determined with logistic regression (LR). Mean BRI (x10(-3)) was 2.12 mm(2), 1.81 mm(2) and 1.7 mm(2) in normal (n = 26), FFKC and KC eyes, respectively (p <0.001). BAD-D (0.79) and BRI (0.74) had the best AUC for FFKC. By combining BAD-D and BRI, the AUC improved to 0.85 (p = 0.01). For KC eyes, KISA (0.94), CLMI (0.88), BAD-D (0.96) and aberrations had comparable AUC (p > 0.05). However, LR with BRI and other indices didn't improve the AUC in KC eyes (p > 0.05). BRI was significantly reduced in FFKC and KC eyes. It improved the detection of FFKC but not KC eyes.

Original languageEnglish
Pages (from-to)701-707
Number of pages7
JournalJournal of Biophotonics
Volume10
Issue number5
DOIs
Publication statusPublished - May 2017

Keywords

  • cornea
  • optical coherence tomography
  • Bowman's layer
  • keratoconus
  • Pentacam
  • FORME-FRUSTE KERATOCONUS
  • KISA-PERCENT INDEX
  • SUBCLINICAL KERATOCONUS
  • CORNEAL TOPOGRAPHY
  • THICKNESS
  • EYES
  • VIDEOKERATOGRAPHY
  • CLASSIFICATION
  • ABERRATIONS
  • PROGRESSION

Cite this