- Journal of Refractive Surgery
- July 2012 - Volume 28 · Issue 7: 475-481
To report the demarcation line depth after corneal collagen cross-linking (CXL) for keratoconus and postoperative LASIK ectasia with Visante (Carl Zeiss Meditec) optical coherence tomography (OCT) and investigate correlations between this depth and preoperative parameters and postoperative visual and keratometry outcomes.
Retrospective interventional case series of 40 eyes with keratoconus or postoperative LASIK ectasia treated with riboflavin ultraviolet-A CXL. Ophthalmic evaluation included uncorrected distance visual acuity, corrected distance visual acuity (CDVA), corneal topography (Pentacam, Oculus Optikgeräte GmbH), and postoperative anterior segment OCT. Correlation analyses were performed. Statistical significance was indicated by P<.05.
At 6 months postoperative, mean demarcation line depth was 281.4±53.3 μm. Thinner minimal corneal thickness (r=0.413, P=.008), older age (r=−0.490, P=.001), higher grading of ectasia (for both keratoconus and postoperative LASIK ectasia) (r=−0.332, P=.044), female sex (r=0.343, P=.030), postoperative LASIK ectasia (r=−0.420, P=.007), and longer duration of disease (r=−0.377, P=.023) were correlated with shallower demarcation line depth. Forward stepwise multiple linear regression analysis showed that among all preoperative factors, minimal corneal thickness (standardized β=0.473, P=.003) and age (standardized β=−0.317, P=.036) were significantly associated with demarcation line depth. The CXL demarcation line depth and change in CDVA (r=−0.16, P=.325) and change of the steepest keratometry at 6 months (r=0.084, P=.637) were not correlated.
The Visante OCT can be used for assessing CXL demarcation line depth. The demarcation line depth may decrease with the severity of ectasia and age.
From the Department of Ophthalmology, Hong Kong Sanatorium and Hospital (Yam, Cheng); and the Department of Ophthalmology, Tung Wah Eastern Hospital (Yam, Chan), Hong Kong, People’s Republic of China.
The authors have no financial or proprietary interest in the materials presented herein.
Correspondence: Arthur C.K. Cheng, MRCS(Ed), FRCophth(HK), Dept of Ophthalmology, Hong Kong Sanatorium and Hospital, 2 Village Road, Happy Valley, Hong Kong, People’s Republic of China. Tel: 852 2835 8880; Fax: 852 2892 7510; E-mail: email@example.com
Received: September 09, 2012
Accepted: May 22, 2012