scholarly journals Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jie Hou ◽  
Yan Wang ◽  
Yulin Lei ◽  
Xiuyun Zheng ◽  
Ying Zhang
Keyword(s):  
Refractive Surgery ◽  
Positive Relationship ◽  
Photorefractive Keratectomy ◽  
Corneal Epithelial ◽  
Thickness Profile ◽  
Epithelial Thickness ◽  
Corneal Asphericity ◽  
Epithelial Remodeling ◽  
Corneal Epithelial Thickness ◽  
Value Changes

Purpose.To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK) for myopia and to investigate the effect of epithelial remodeling on corneal asphericity.Methods.Forty-four patients (44 right eyes) who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2–5 mm; and mid-peripheral, 5-6 mm) preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET) and postoperativeQ-value changes (ΔQ) was analyzed 6 months postoperatively.Results.Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69±4.2,5.19±3.8, and6.23±3.9 μm at the center, paracenter, and mid-periphery, resp.,P<0.01). A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r=0.438, 0.580, and 0.504, resp.,P<0.01).Conclusions.Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia.

scholarly journals Corneal Epithelial Thickness Profile in Healthy Portuguese Children by High-Definition Optical Coherence Tomography

2021 ◽  
Vol Volume 15 ◽  
pp. 735-743
Author(s):  
Tomás de Oliveira Loureiro ◽  
Sandra Rodrigues-Barros ◽  
Diogo Lopes ◽  
Ana Rita Carreira ◽  
Filipe Gouveia-Moraes ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence ◽  
High Definition ◽  
Corneal Epithelial ◽  
Thickness Profile ◽  
Epithelial Thickness ◽  
Corneal Epithelial Thickness

scholarly journals Corneal epithelial thickness profile in dry-eye disease

Eye ◽  
2019 ◽  
Vol 34 (5) ◽  
pp. 915-922 ◽  
Author(s):  
Mohamed Abou Shousha ◽  
Jianhua Wang ◽  
George Kontadakis ◽  
William Feuer ◽  
Ana P. Canto ◽  
...  
Keyword(s):  
Dry Eye ◽  
Dry Eye Disease ◽  
Eye Disease ◽  
Corneal Epithelial ◽  
Thickness Profile ◽  
Epithelial Thickness ◽  
Corneal Epithelial Thickness

Corneal Epithelial Thickness Mapping After Photorefractive Keratectomy for Myopia

2019 ◽  
Vol 35 (10) ◽  
pp. 632-641
Author(s):  
Mohammad-Reza Sedaghat ◽  
Hamed Momeni-Moghaddam ◽  
Mehrdad Gazanchian ◽  
Dan Z. Reinstein ◽  
Timothy J. Archer ◽  
...  
Keyword(s):  
Photorefractive Keratectomy ◽  
Corneal Epithelial ◽  
Epithelial Thickness ◽  
Corneal Epithelial Thickness

scholarly journals Assessment of Corneal Epithelial Thickness in Chronic Contact Lens Users Using Anterior Segment Optical Coherence Tomography

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
A A M E A Rezk ◽  
A Assaf ◽  
M Gamil ◽  
T Badran
Keyword(s):  
Contact Lens ◽  
Corneal Epithelium ◽  
Refractive Surgery ◽  
Anterior Segment ◽  
Control Group ◽  
Soft Contact ◽  
Corneal Epithelial ◽  
Epithelial Thickness ◽  
Soft Contact Lens ◽  
Corneal Epithelial Thickness

Abstract Introduction The corneal epithelium is stratified epithelium that is continuously renewed and provides the frontline of defence against invading ocular pathogens and a smooth refractive surface essential for vision. In the absence of a contact lens, pre-existing ocular trauma or disease, the epithelium maintains an inaccessible defence against attacks from pathogenic microorganisms, affording a high level of resistance against microbial invasion. Aim The aim of this study is to determine the effect of chronic use of contact lens on corneal epithelium thickness using anterior segment optical coherence topography as a non- invasive diagnostic accurate measure. Patients and Methods 30 eyes of control subjects who don’t wear contact lens along their life aged between 15-45 years ,where compared with similar age group of 30 eyes of chronic contact lens users; who wear contact lens every day not less than 8 hours per day for along time interval between 6 months up to 5 years. Results The average corneal epithelial thickness in the central, paracentral and midperipheral zones was 47.767 ± 5.550 µm, 46.267 ± 5.644 µm, 44.300 ± 4.858 µm, respectively, in chronic soft contact lens users; and 49.800 ± 3.316 µm, 49.200 ± 3.367 µm, 45.733 ± 2.333 µm ,in control group who had never worn contact lens. There were insignificant thinning of corneal epithelium of soft contact group compared to control group regarding the average corneal epithelial thickness in those 3 zones. In all the 8 sectors of corneal epithelium of paracentral zone and midperipheral zones there is insignificant thinning between the two groups except for the inferior temporal sector in the paracentral zone and mid peripheral zone, which shows significant thinning in soft contact lens group compared to control group. The corneal epithelial thickness in the inferior temporal sector of paracentral and mid peripheral zones was 46.333 ± 5.677 µm, 44.933 ± 4.813 µm, respectively, in chronic soft contact lens users compared to 48.767 ± 3.266 µm, 46.900 ± 2.510 µm in control group (p = 0.046, p = 0.052, respectively). Conclusion AS-OCT helps us to evaluate the corneal epithelium of contact lens users, which could be very useful in corneal refractive surgeries in patients depending on contact lens in their lives as a comfortable refractive aid, It is necessary to do AS-OCT hand on hand with pentacam in patients underwhelming refractive surgery to give a proper assessment to their corneal epithelium before determining which type of refractive surgery suits them.

scholarly journals Corneal Epithelial Remodeling after LASIK Measured by Fourier-Domain Optical Coherence Tomography

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Maolong Tang ◽  
Yan Li ◽  
David Huang
Keyword(s):  
Mathematical Model ◽  
Fourier Domain ◽  
Spherical Equivalent ◽  
Thickness Change ◽  
Corneal Epithelial ◽  
Epithelial Thickness ◽  
Before And After ◽  
Epithelial Remodeling ◽  
Corneal Epithelial Thickness ◽  
Fourier Domain Oct

Purpose. To quantify corneal epithelial thickness changes after myopic LASIK by OCT.Methods.Epithelial thickness before and after myopic LASIK were measured by a Fourier-domain OCT system. Average central (within 1 mm diameter) and paracentral epithelial thickness (5~6 mm diameter) before and after LASIK were compared. Correlation between central epithelial thickness change and laser spherical equivalent setting was evaluated. An epithelial smoothing constant was estimated based on a mathematical model published previously.Results.Nineteen eyes from 11 subjects were included in the study. Eyes had myopic LASIK ranging from −1.69 D to −6.75 D spherical equivalent. The average central epithelial thickness was 52.6 ± 4.1 μm before LASIK and 56.2 ± 4.3 μm 3 months after LASIK (p=0.002). The average paracentral epithelial thickness was 51.6 ± 6.6 μm before LASIK and 54.8 ± 4.3 μm 3 months after LASIK (p=0.007). The change in average central epithelial thickness was correlated with laser spherical equivalent (R2= 0.40,p=0.028). The epithelial smoothing constant was estimated to be 0.46 mm.Conclusions. Corneal epithelial thickens centrally and paracentrally after myopic LASIK. The extent of epithelial remodeling correlated with the amount of LASIK correction and could be predicted by a mathematical model.

Comparison of corneal epithelial thickness profile in dry eye patients, keratoconus suspect, and healthy eyes

2020 ◽  
Vol 30 (6) ◽  
pp. 1506-1511
Author(s):  
Suzan Amana Rattan ◽  
Didar Sddeq Anwar
Keyword(s):  
Dry Eye ◽  
Corneal Topography ◽  
P Value ◽  
Dry Eyes ◽  
Corneal Epithelial ◽  
Thickness Profile ◽  
Epithelial Thickness ◽  
Significant Difference ◽  
Corneal Epithelial Thickness ◽  
Healthy Eyes

Purpose: To compare the corneal epithelial thickness profile in patients with dry eyes and keratoconus suspect with normal healthy eyes. Methods: The study involved 120 eyes with an age range from 19 to 30 years. Forty eyes had normal corneal topography and no dry eyes. Forty eyes had dry eyes but had normal corneal topography. The last 40 eyes were keratoconus suspect and had no symptoms or signs of dry eyes. Results: Central epithelial thickness was not different statistically for all eyes. ( p-value: 0.1). The superior epithelial thickness was 53.5 µm ±3.1 in the control group, 53.4 µm ±3.5 in the dry eye group, and 53.6 µm ±2.8 in the keratoconus suspect group. No statistically significant difference was found ( p-value = 0.7). The inferior epithelial thickness was 55.7 µm ±3.5 in the control, 57.2 µm ±3.19 in the dry eyes, and 52.2 µm ±3.12 in the KC suspects. There was inferior thickening in the dry eyes and thinning in the KC suspects and this was statistically significant ( p-value < 0.01). Minimum epithelial thickness was 52.8 µm ±2.91 in the control and 53.2 µm ±3.51 in the dry eyes and it was located superiorly for both groups. In the KC suspects, the minimum thickness was 52.3 µm ±3.19 and was located inferiorly. Conclusion: In our study the epithelium appears to be thicker inferiorly in dry eyes and thinner in KC suspects. Displacement of thinnest location on epithelial map may be a helpful early sign of keratoconus. However, follow-up study is necessary to confirm the thinnest location displacement helped in this diagnosis.

scholarly journals Corneal epithelial thickness analysis of forme fruste keratoconus with optical coherence tomography

2021 ◽  
Vol 14 (1) ◽  
pp. 89-96
Author(s):  
Xiao-Long Yang ◽  
◽  
Bao-Gen Luo ◽  
Yue Xu ◽  
Xiao-Feng Zhang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Epithelium ◽  
Optical Coherence ◽  
Topographic Map ◽  
Corneal Epithelial ◽  
Epithelial Thickness ◽  
Central Island ◽  
Epithelial Remodeling ◽  
Corneal Epithelial Thickness ◽  
Forme Fruste Keratoconus

AIM: To explore the significance of corneal epithelial thickness analysis in diagnosing early keratoconus. METHODS: There were 26 clinical keratoconus, 21 forme fruste keratoconus, 40 high corneal astigmatism (ΔK) and 40 low ΔK eyes involved in the study. Fourier-domain optical coherence tomography was used to measure the corneal epithelial thickness of four groups. The morphological features of topographic map and the thickness of corneal epithelial thinnest point were analyzed. The distribution curve of corneal epithelial thickness at 45°, 90°, and 135° axial directions that are through the pupil center was also analyzed. One-way ANOVA was performed to compare the data. RESULTS: The topographic map of forme fruste keratoconus corneal epithelial thickness was uniformity shape; crater shape existed only in clinical keratoconus group; and central island shape mainly existed in high ΔK group. The thinnest point of corneal epithelial thickness of forme fruste keratoconus group was significantly lower than that of low ΔK group (P=0.022). The thickness of corneal epithelium in the forme fruste keratoconus at 90° was thinner than that in the low astigmatism group at -1, and -2 mm points (P-1 mm=0.015, P-2 mm=0.036). CONCLUSION: The analysis of the thinnest point in forme fruste keratoconus corneal epithelium appears earlier than corneal epithelial remodeling. The topographic map of corneal epithelium in high ΔK eyes appears in central island shape, and can be used for the differential diagnosis of early keratoconus.

The effect of PRK on corneal epithelium thickness and pachmetry in treatment of myopia.

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Furkaan Majied Hamied ◽  
Deyaa Neama Kadhim ◽  
Sohaib A Mahmood
Keyword(s):  
Refractive Error ◽  
Anterior Segment ◽  
Thickness Change ◽  
Corneal Epithelial ◽  
Epithelial Thickness ◽  
Refractive Outcomes ◽  
Epithelium Thickness ◽  
Profile Changes ◽  
Corneal Epithelial Thickness ◽  
Myopic Astigmatism

In order to facilitate the corneal stromal ablation in photorefractive keratectomy the epithelium is removed so corneal repair associated with changes in epithelium and stroma. To study the corneal epithelial thickness and pachymetry profile changes after photorefractive keratec­tomy (PRK) for myopia. Retrospective analysis of the postoperative corneal epithelial thickness and pachymetry profile changes in 22 eyes of 12 patients treated with PRK for myopia or myopic astigmatism. Corneal and epithelial thickness maps within the central 6 mm were obtained by anterior segment spectral-domain optical coherence tomography (SD-OCT) preop­eratively and at 3 months postoperatively. Correlations between pachymetry,epithelial thickness changes and the amount of correction,were analyzed.Compared to preoperative values,the central 2 mm and the paracentral 2 to 5 mm zone epithelium was 1 ± 2.85 and 1 ± 3.11 μm thicker,respec­tively,at 3 months postoperatively (P <.05). The spheri­cal equivalent (SE) changed from-2.80 ± 2.028 diop­ters (D) preoperatively to -0.40 ± 0.42 D at 3 months postoperatively. Females show greater postoperative epithelial thickening, 2.6 ± 3.77 μm,than males,0.34 ± 1.98 μm. There was a trend toward greater epithelial thickening with a larger amount of programmed SE correction, and thinner preoperative epithelium. No correlation between epithelial thickness change and postoperative change in refraction was detected.Negative correlation between between age, refractive error,with the pre and post-operative pachymetry. In general female pachymetry reading is higher than it in male.The corneal epithelial thickness in­creased after PRK up to 3 months postoperatively. It was affected by the amount of myopia treated, gender, and preoperative epithelial thickness. The refractive outcomes did not affected by the postoperative epithelial thickening. Negative correlation between between age, refractive error, with the pre and post-operative pachymetry. In general female pachymetry reading is higher than it in male.

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