Optical coherence tomography–derived corneal thickness asymmetry indices: Clinical reference study of normal eyes

Kanellopoulos, Anastasios John; Chiridou, Marianthi; Asimellis, George

doi:10.1016/j.jcrs.2014.01.041

Cited by 11 publications

(8 citation statements)

References 23 publications

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“…These differences might be explained by the instruments used for measurement; the thickness measured by FD-OCT was usually smaller than that measured by Pentacam or ultrasound pachymetry [ 14 , 19 ]. Our results were comparable to the mean CCT reported in normal adults measured using FD-OCT (532 μm in 66 eyes of subjects at a mean age of 35.39±10.6 years, and 537 μm in 561 eyes of subjects at a mean age of 45.70±21.20 years) [ 13 , 20 ].…”

Section: Discussionsupporting

confidence: 87%

Corneal Thickness Profile and Associations in Chinese Children Aged 7 to 15 Years Old

Zhu

et al. 2016

PLoS ONE

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Corneal thickness (CT) maps of the central (2-mm diameter), para-central (2 to 5-mm diameter), peripheral (5 to 6-mm diameter), and minimum (5-mm diameter) cornea were measured in normal Chinese school children aged 7 to 15 years old using Fourier-domain optical coherence tomography. Multiple regression analyses were performed to explore the effect of associated factors [age, gender, refraction, axial length and corneal curvature radius (CCR)] on CT and the relationship between central corneal thickness (CCT) and intraocular pressure (IOP). A total of 1228 eyes from 614 children were analyzed. The average CCT was 532.96 ± 28.33 μm for right eyes and 532.70 ±28.45 μm for left eyes. With a 10 μm increase in CCT, the IOP was elevated by 0.37 mm Hg, as measured by noncontact tonometry. The CT increased gradually from the center to the periphery. The superior and superior nasal regions had the thickest CTs, while the thinnest points were primarily located in the inferior temporal cornea. The CCT was associated with CCR (p = 0.008) but not with gender (p = 0.075), age (p = 0.286), axial length (p = 0.405), or refraction (p = 0.985). In the para-central region and the peripheral cornea, increased CT was associated with younger age, male gender, and a flatter cornea.

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Section: Discussionsupporting

confidence: 87%

Corneal Thickness Profile and Associations in Chinese Children Aged 7 to 15 Years Old

Zhu

et al. 2016

PLoS ONE

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“…It could be the irregular corneal shape and thickness (although normalization of the epithelium following corneal cross-linking treatment minimizes the influence of this theory), as has been introduced by our team 7. It could be related to eye rubbing, although regular stability of the epithelial maps through long-term investigation also minimized the potential influence of this theory.…”

Section: Discussionmentioning

confidence: 99%

“…Specifically, overall corneal epithelial thickness,4,5 as well as epithelial thickness topographic variability, may serve as diagnostic elements, in synergy with other topographic and Scheimpflug tomographic screening indicators, such as irregular corneal thickness6,7 and anterior-surface topographic variability 8,9…”

Section: Introductionmentioning

confidence: 99%

OCT corneal epithelial topographic asymmetry as a sensitive diagnostic tool for early and advancing keratoconus

Kanellopoulos¹,

Asimellis²

2014

OPTH

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PurposeTo investigate epithelial thickness-distribution characteristics in a large group of keratoconic patients and their correlation to normal eyes employing anterior-segment optical coherence tomography (AS-OCT).Materials and methodsThe study group (n=160 eyes) consisted of clinically diagnosed keratoconus eyes; the control group (n=160) consisted of nonkeratoconic eyes. Three separate, three-dimensional epithelial thickness maps were obtained employing AS-OCT, enabling investigation of the pupil center, average, mid-peripheral, superior, inferior, maximum, minimum, and topographic epithelial thickness variability. Intraindividual repeatability of measurements was assessed. We introduced correlation of the epithelial data via newly defined indices. The epithelial thickness indices were then correlated with two Scheimpflug imaging-derived AS-irregularity indices: the index of height decentration, and the index of surface variance highly sensitive to early and advancing keratoconus diagnosis as validation.ResultsIntraindividual repeatability of epithelial thickness measurement in the keratoconic group was on average 1.67 μm. For the control group, repeatability was on average 1.13 μm. In the keratoconic group, pupil-center epithelial thickness was 51.75±7.02 μm, while maximum and minimum epithelial thickness were 63.54±8.85 μm and 40.73±8.51 μm. In the control group, epithelial thickness at the center was 52.54±3.23 μm, with maximum 55.33±3.27 μm and minimum 48.50±3.98 μm epithelial thickness. Topographic variability was 6.07±3.55 μm in the keratoconic group, while for the control group it was 1.59±0.79 μm. In keratoconus, topographic epithelial thickness change from normal, correlated tightly with the topometric asymmetry indices of IHD and ISV derived from Scheimpflug imaging.ConclusionSimple, OCT-derived epithelial mapping, appears to have critical potential in early and advancing keratoconus diagnosis, confirmed with its correlation with established Scheimpflug-derived asymmetry topometric indices.

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“…38 Cataract surgery can damage corneal epithelium and epithelial thickness is associated with local irregularities of corneal topography that contribute to the optical power of the cornea. 39 Furthermore, signi cant changes in epithelial thickness have been correlated with corneal instability. 40 It was found that epithelial thickness increased 1 day postoperatively and decreased after 1 week.…”

Section: Discussionmentioning

confidence: 99%

Changes In Corneal Surface Aberrations And Nerve Density After Cataract Surgery Of Patients With Dry Eye Disease

Jing

Jiang

Chou

et al. 2022

Preprint

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Purpose: To evaluate the change patterns in corneal aberrations and nerve density after cataract surgery in dry eye disease (DED).Methods: One hundred and six eyes of 69 patients with dry eye were included in this study. The preoperative, 1-month and 3-month postoperative dry eye-related indices were obtained by the Oculus keratograph and the ocular surface disease index (OSDI) questionnaire. The corneal aberrations and corneal surface regularity indices were measured using a Pentacam HR system. In vivo confocal microscopy (ICVM) was performed to observe sub-basal corneal nerves of vortex and superior periphery, and corneal endothelial number. An artificial intelligence (AI) technique run by the deep learning model generated the sub-basal nerve fibre parameters.Results: One hundred and six eyes of 69 patients with DED (mean age, 69.32±8.91 years) were recruited. Corneal aberrations on the anterior and total corneal surfaces increased significantly at 1 month after surgery compared with the baseline values but gradually returned to the baseline by 3 months after surgery. Significant changes in posterior corneal HOAs occurred at 1-month and 3-month. Corneal endothelial cells decreased continuously until 3 months after operation. There were significantly lessen in corneal vortical nerve maximum length and average density after operation, these damages were present after 3 months. But for corneal peripheral nerve, these damages lasted only 1 month after operation. The corneal vortical nerve maximum length and average density were negatively correlated with anterior corneal surface aberrations before and one month after surgery. Conclusions: After cataract surgery, changes in corneal aberrations occurred mainly both on the anterior and posterior surface. However, the change of posterior lasts longer. The corneal vortical nerve maximum length and average density are reduced after cataract surgery in patients with DED. Although the anterior corneal aberration will recover one month after cataract surgery, the dry eye state continues to worsen. IVCM is a useful tool to evaluate corneal sub-basal nerve changes in dry eye patients before and after cataract operation.

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Optical coherence tomography–derived corneal thickness asymmetry indices: Clinical reference study of normal eyes

Abstract: Dr. Kanellopoulos is a consultant to Alcon Laboratories, Inc., Allergan, Inc., Avedro, Inc., Keramed, Inc., and i-Optics. No other author has a financial or proprietary interest in any material or method mentioned.

Cited by 11 publications

References 23 publications

Corneal Thickness Profile and Associations in Chinese Children Aged 7 to 15 Years Old

Corneal Thickness Profile and Associations in Chinese Children Aged 7 to 15 Years Old

OCT corneal epithelial topographic asymmetry as a sensitive diagnostic tool for early and advancing keratoconus

Changes In Corneal Surface Aberrations And Nerve Density After Cataract Surgery Of Patients With Dry Eye Disease

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Optical coherence tomography–derived corneal thickness asymmetry indices: Clinical reference study of normal eyes

Abstract: Dr. Kanellopoulos is a consultant to Alcon Laboratories, Inc., Allergan, Inc., Avedro, Inc., Keramed, Inc., and i-Optics. No other author has a financial or proprietary interest in any material or method mentioned.

Cited by 11 publications

References 23 publications

Corneal Thickness Profile and Associations in Chinese Children Aged 7 to 15 Years Old

Corneal Thickness Profile and Associations in Chinese Children Aged 7 to 15 Years Old

OCT corneal epithelial topographic asymmetry as&nbsp;a sensitive diagnostic tool for early and advancing keratoconus

Changes In Corneal Surface Aberrations And Nerve Density After Cataract Surgery Of Patients With Dry Eye Disease

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OCT corneal epithelial topographic asymmetry as a sensitive diagnostic tool for early and advancing keratoconus