scholarly journals Redistribution of the Corneal Epithelium After Overnight Wear of Orthokeratology Contact Lenses for Myopia Reduction

2018 ◽  
Author(s):  
Ju Zhang ◽  
Jing Li ◽  
Xiaofeng Li ◽  
Fengjie Li ◽  
Ting Wang
Keyword(s):  
Visual Acuity ◽  
Corneal Epithelium ◽  
Contact Lenses ◽  
Early Stage ◽  
Corneal Thickness ◽  
Topographic Map ◽  
Epithelial Thickness ◽  
Uncorrected Visual Acuity ◽  
Before And After ◽  
Epithelium Thickness

Abstract Background: To investigate changes in the corneal epithelium topographic map in juvenile myopia after overnight wear of orthokeratology lenses (OK). Methods: A total of 53 juveniles (53 right eyes) successfully wore OK and were reviewed in a timely manner from January 2016 to July 2017. Epithelial and corneal data were obtained by optical coherence tomography (OCT). Changes in uncorrected visual acuity, diopter, corneal refractive power, and epithelial and corneal thickness were analyzed before and after 1 day, 1 week, and 1 mo of overnight wear of OK. Results: The corneal epithelium was reshaped after 1 day of OK; the myopia degree was reduced, and uncorrected visual acuity reached 0 logMAR at 1 week. The central (2-mm) average epithelial thickness was 52.04±2.35 μm, 49.25±2.67 μm, 45.91±2.80 μm, and 47.53±3.44 μm before and after 1 day, 1 week, and 1 mo of OK, respectively (t=10.122, 10.782, and 10.673, respectively, P≤0.001). The central epithelium appeared to have a thinning trend, which was obvious at 1 week, when the average thinning of 6.13±1.67 μm accounted for approximately 11.78%±3.21% of the total epithelium thickness. The epithelial thickness of the reverse curve zone was 51.83±2.49 μm, 57.62±3.01 μm, 59.43±3.19 μm, and 60.22±2.75 μm before and after 1 day, 1 week, and 1 mo of OK, respectively, showing a significant increase over time (t=5.325, 6.177, and 6.312, respectively, P≤0.001). Conclusion: In the early stage of OK, the corneal epithelium was redistributed very quickly. The central epithelium became thin, while the epithelium of the reverse curve zone correspondingly thickened and achieved a plateau at 1 mo. Epithelial redistribution guaranteed uncorrected visual acuity after removal of OK.

scholarly journals Redistribution of the Corneal Epithelium After Overnight Wear of Orthokeratology Contact Lenses for Myopia Reduction

2019 ◽  
Author(s):  
Ju Zhang ◽  
Jing Li ◽  
Xiaofeng Li ◽  
Fengjie Li ◽  
Ting Wang
Keyword(s):  
Visual Acuity ◽  
Corneal Epithelium ◽  
Contact Lenses ◽  
Early Stage ◽  
Corneal Thickness ◽  
Topographic Map ◽  
Epithelial Thickness ◽  
Uncorrected Visual Acuity ◽  
Before And After ◽  
Epithelium Thickness

Abstract Background: To investigate changes in the corneal epithelium topographic map in juvenile myopia after overnight wear of orthokeratology lenses (OK). Methods: A total of 53 juveniles (53 right eyes) successfully wore OK and were reviewed in a timely manner from January 2016 to July 2017. Epithelial and corneal data were obtained by optical coherence tomography (OCT). Changes in uncorrected visual acuity, diopter, corneal refractive power, and epithelial and corneal thickness were analyzed before and after 1 day, 1 week, and 1 mo of overnight wear of OK. Results: The corneal epithelium was reshaped after 1 day of OK; the myopia degree was reduced, and uncorrected visual acuity reached 0 logMAR at 1 week. The central (2-mm) average epithelial thickness was 52.04±2.35 μm, 49.25±2.67 μm, 45.91±2.80 μm, and 47.53±3.44 μm before and after 1 day, 1 week, and 1 mo of OK, respectively (t=10.122, 10.782, and 10.673, respectively, P≤0.001). The central epithelium appeared to have a thinning trend, which was obvious at 1 week, when the average thinning of 6.13±1.67 μm accounted for approximately 11.78%±3.21% of the total epithelium thickness. The epithelial thickness of the reverse curve zone was 51.83±2.49 μm, 57.62±3.01 μm, 59.43±3.19 μm, and 60.22±2.75 μm before and after 1 day, 1 week, and 1 mo of OK, respectively, showing a significant increase over time (t=5.325, 6.177, and 6.312, respectively, P≤0.001). Conclusion: In the early stage of OK, the corneal epithelium was redistributed very quickly. The central epithelium became thin, while the epithelium of the reverse curve zone correspondingly thickened and achieved a plateau at 1 mo. Epithelial redistribution guaranteed uncorrected visual acuity after removal of OK.

scholarly journals The effectiveness of hyperopia correction by wearing contact lenses in school-age children in the long-term follow-up

2021 ◽  
Vol 9 (3) ◽  
pp. 6-13
Author(s):  
N.M. Aleeva
Keyword(s):  
Visual Acuity ◽  
Contact Lenses ◽  
Corneal Thickness ◽  
Oculomotor System ◽  
School Age Children ◽  
School Age ◽  
Silicone Hydrogel ◽  
Uncorrected Visual Acuity ◽  
Long Term Follow Up ◽  
High Degree

Background. Glasses and correction by wearing contact lenses are well tolerated by children with mild to moderate ametropia. In ametropia of high degree, an improvement of mo­nocular visual acuity with a contact lens compared to correction by glasses is 3.8 times higher. Materials and methods. The study included 56 children (112 eyes) aged 6 to 16 years with hypero­pic refraction and astigmatism, who used soft silicone hydrogel contact lenses to correct ametropia. In these patients, visual acui­ty, objective and subjective clinical refraction, axial length of the eye, corneal thickness and diameter, keratometry indicators were investigated, as well as phorometric data (accommodation, vergence, disparity areas of the oculomotor system and their inte­raction) in the early and late observation periods. Results. When using contact lenses for correction in school-age children with hyperopia and hyperopic astigmatism, after 3 years of observation there was a statistically significant increase in uncorrected visual acuity by 85 % (t = 7.9; p < 0.01), corrected visual acuity by 7 % (t = 7.4; p < 0.01), keratometry indicator in the weakest meridian by 1 % (t = 6.1; p < 0.01), in the strongest meridian by 1 % (t = 8.9; p < 0.01), central corneal thickness by 4 % (t = 4.6; p < 0.01), as well as a decrease in the spherical equivalent by 38 % (t = 3.1; p < 0.01), the amplitude of accommodation by 20 % (t = 5.8; p < 0.01), the negative relative accommodation by 20 % (t = 3.0; p < 0.01), the positive relative accommodation by 18 % (t = 3.5; p < 0.01), excessive accommodative response by 64 % (t = 7.2; p < 0.01), near phoria by 33 % (t = 4.4; p < 0.01), distance phoria by 22 % (t = 2.8; p < 0.01), the accommodation convergence to accommodation ratio by 18 % (t = 3.1; p < 0.01).

scholarly journals Whether Keratectasia Area Shown in Corneal Topography Is Appropriate for Evaluating the Effect of Corneal Cross-Linking for Keratoconus: A 12-Month Follow-Up Study

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Jia Wang ◽  
Zhiwei Li ◽  
Huankai Zhang ◽  
Ning Gao ◽  
Guoying Mu
Keyword(s):  
Endothelial Cell ◽  
Linear Regression ◽  
Early Stage ◽  
Morphological Changes ◽  
Corneal Thickness ◽  
Corneal Topography ◽  
Cross Linking ◽  
Follow Up Study ◽  
Before And After

Purpose. To analyze the keratectasia area (KEA) shown in corneal topography before and after corneal cross-linking (CXL) in patients with progressive keratoconus (KC) and figure out whether KEA is appropriate for evaluating the effect of CXL. Methods. A retrospective analysis was conducted in 34 eyes from 24 progressive KC patients who have underwent CXL from 2015 to 2017. Area with K-value more than 47D shown in the corneal topography was marked and identified as KEA. Keratometry (K1, K2, and Kmax), KEA, thinnest corneal thickness (TCT), and endothelial cell density (ECD) were evaluated preoperatively or at months 3, 6, and 12 postoperatively. The changes of KEA before and after operation were evaluated. The relation of KEA and other parameters, including Kmax and TCT, was analyzed. Results. Linear regression model revealed the KEA, Kmax, K1, and K2 decreased after CXL in model y = 0.9622 -0.02408 x (P<0.05), y = 0.9982 -0.003469 x(P<0.05), y = 0.9977 + -0.001347 x(P<0.05), y = 0.9992 + -0.001779 x(P<0.05) (y represents KEA, Kmax, K1, or K2; x represents time (month)). The KEA is significantly decreased in early stage (before month 3) (P<0.05); however, the Kmax, K1, and K2 have no significant decrease in early stage (P= 0.09, 0.19, 0.32). Conclusions. The KEA is more sensitive than K-value in describing the morphological changes of cornea after CXL, especially in early stage after treatment.

scholarly journals Clinical Performance of Toris K Contact Lens in Patients with Moderate to Advanced Keratoconus: A Real Life Retrospective Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Ihsan Yilmaz ◽  
Ferah Ozcelik ◽  
Berna Basarir ◽  
Gokhan Demir ◽  
Gonul Durusoy ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contact Lens ◽  
Contact Lenses ◽  
Clinical Performance ◽  
Real Life ◽  
Soft Contact Lenses ◽  
Corrected Visual Acuity ◽  
Uncorrected Visual Acuity ◽  
Central Cone ◽  
The Mean

Objectives.To evaluate the visual performance of Toris K soft contact lenses in patients with moderate-to-advanced keratoconus and also to compare the results according to cone types, cone location, and severity of keratoconus.Materials and Methods.Sixty eyes of 40 participants were included in this retrospective study. Uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BCVA), best-contact lens corrected visual acuity (BCLCVA), and comfort rating via visual analogue scales (VAS) were measured.Results.The mean age was 27.3 ± 8.6 years (range: 18 to 54). The mean logMAR UCVA, BCVA, and BCLCVA were 0.85 ± 0.38 (range: 0.30–1.30), 0.47 ± 0.27 (range: 0.10–1.30), and 0.16 ± 0.20 (range: 0–1.00). There were significant increases in visual acuities with contact lenses (p<.05). BCLCVA was significantly better in oval type than globus type (p=.022). UCVA and BCLCVA were significantly better in moderate keratoconus group (p=.015,p=.018). The mean line gain in Snellen was 3.6 ± 1.8 lines (range: 0–7 lines). The mean line gain was higher in central cone group than paracentral cone group and oval group than globus group (p=.014,p=.045). The mean VAS score was 8.14 ± 1.88 (range: 6–10).Conclusions.Toris K can improve visual acuity of patients with keratoconus. Toris K is successful even in the moderate and advanced form of the disease.

scholarly journals Clinical Outcomes of Small Incision Lenticule Extraction with Accelerated Cross-Linking (ReLEx SMILE Xtra) in Patients with Thin Corneas and Borderline Topography

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Sri Ganesh ◽  
Sheetal Brar
Keyword(s):  
Visual Acuity ◽  
Clinical Outcomes ◽  
Corneal Thickness ◽  
Cross Linking ◽  
Small Incision Lenticule Extraction ◽  
Uncorrected Visual Acuity ◽  
Distant Visual Acuity ◽  
Lenticule Extraction ◽  
The Mean

Purpose. To study the safety and clinical outcomes of ReLEx SMILE with accelerated cross-linking in individuals with thinner corneas, borderline topography, and higher refractive errors.Methods. Eligible patients first underwent SMILE procedure for correction of myopic refractive error. Following the removal of lenticule, 0.25% riboflavin in saline was injected into the interface and allowed to diffuse for 60 seconds. Finally, eye was exposed to UV-A radiation of 45 mW/cm2for 75 seconds through the cap. Total energy delivered was 3.4 J/cm2.Results. 40 eyes of 20 patients with mean age of 26.75 ± 5.99 years were treated. Mean follow-up was 12 months ± 28.12 days. Mean spherical equivalent (SE) was −5.02 ± 2.06 D preoperatively and −0.24 ± 0.18 D postoperatively. The mean central corneal thickness (CCT) and keratometry changed from 501 ± 25.90 µm to 415 ± 42.26 µm and 45.40 ± 1.40 D to 41.2 ± 2.75 D, respectively. Mean uncorrected visual acuity (UCVA) was 20/25 or better in all eyes. No eyes lost lines of corrected distant visual acuity (CDVA). There were no complications like haze, keratitis, ectasia, or regression.Conclusion. Based on the initial clinical outcome it appears that SMILE Xtra may be a safe and feasible modality to prevent corneal ectasia in susceptible individuals.

scholarly journals Simultaneous Topography-guided Surface Ablation with Collagen Cross-linking for Keratoconus

2016 ◽  
Vol 5 (2) ◽  
pp. 71-76
Author(s):  
Igor Kaiserman ◽  
Lily Karmona ◽  
Tzahi Sela ◽  
Oz Franco ◽  
Avi Shoshani ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contact Lenses ◽  
Cross Linking ◽  
Visual Rehabilitation ◽  
Surface Ablation ◽  
Uncorrected Visual Acuity ◽  
Promising Treatment ◽  
Functional Vision ◽  
Collagen Cross Linking

ABSTRACT Purpose In this article, we present the results of eight eyes of patients who underwent combined same-day partial topography-guided surface ablation followed by accelerated collagen cross-linking (CXL) procedure at Care-Vision Laser Centers to achieve stabilization of corneal ectasia and enhance visual rehabilitation in keratoconus. Materials and methods A retrospective nonrandomized review of 8 eyes of 6 patients who underwent the Athens Protocol for progressive keratoconus. Each patient underwent topography-guided ablation followed by CXL procedure. Follow-up Follow-up was done on day 1, day 7, and then at 1, 3, 6, and 12 months. Results There was a rapid and significant improvement in uncorrected visual acuity and best-corrected visual acuity in 100% eyes, a reduction of keratometric values, and symmetry between vertical hemimeridians. Topographic evaluation showed a marked improvement in irregularity. There were no signs of keratoconic progression noted in any of the eyes on last follow-up. No adverse events were reported in any patient. Conclusion Simultaneous surface ablation + CXL seems to be a promising treatment capable of offering patients functional vision and halting progression of the disorder. Precis Simultaneous topography-guided custom ablation treatment and photorefractive keratectomy with CXL offers keratoconic patients intolerant to contact lenses both stabilization of the cornea and improved functional vision with spectacles correction. How to cite this article Karmona L, Sela T, Franco O, Shoshani A, Munzer G, Kaiserman I. Simultaneous Topography-guided Surface Ablation with Collagen Cross-linking for Keratoconus. Int J Kerat Ect Cor Dis 2016;5(2):71-76.

scholarly journals A new approach for quantifying epithelial and stromal thickness changes after orthokeratology contact lens wear

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Ziying Ran ◽  
Joshua Moore ◽  
Fan Jiang ◽  
Hongmei Guo ◽  
Ashkan Eliasy ◽  
...  
Keyword(s):  
Corneal Epithelium ◽  
Contact Lenses ◽  
Automatic Segmentation ◽  
Central Area ◽  
Radius Of Curvature ◽  
Corneal Surface ◽  
Contact Lens Wear ◽  
Thickness Profile ◽  
Before And After ◽  
Lens Wear

The aim of the study was to develop an automatic segmentation approach to optical coherence tomography (OCT) images and to investigate the changes in epithelial and stromal thickness profile and radius of curvature after the use of orthokeratology (Ortho-K) contact lenses. A total of 45 right eyes from 52 participants were monitored before, and after one month of, uninterrupted overnight Ortho-K lens wear. The tomography of their right eyes was obtained using optical OCT and rotating Scheimpflug imaging (OCULUS Pentacam). A custom-built MATLAB code for automatic segmentation of corneal OCT images was created and used to assess changes in epithelial thickness, stromal thickness, corneal and stromal profiles and radii of curvature before, and after one month of, uninterrupted overnight wear of Ortho-K lenses. In the central area (0–2 mm diameter), the epithelium thinned by 12.8 ± 6.0 µm (23.8% on average, p < 0.01) after one month of Ortho-K lens wear. In the paracentral area (2–5 mm diameter), the epithelium thinned nasally and temporally (by 2.4 ± 5.9 µm, 4.5% on average, p = 0.031). The stroma thickness increased in the central area (by 4.8 ± 16.1 µm, p = 0.005). The radius of curvature of the central corneal anterior surface increased by 0.24 ± 0.26 mm (3.1%, p < 0.01) along the horizontal meridian and by 0.34 ± 0.18 mm (4.2%, p < 0.01) along the vertical meridian. There were no significant changes in the anterior and posterior stromal radius of curvature. This study introduced a new method to automatically detect the anterior corneal surface, the epithelial posterior surface and the posterior corneal surface in OCT scans. Overnight wear of Ortho-K lenses caused thinning of the central corneal epithelium. The anterior corneal surface became flattered while the anterior and posterior surfaces of the stroma did not undergo significant changes. The results are consistent with the changes reported in previous studies. The reduction in myopic refractive error caused by Ortho-K lens wear was mainly due to changes in corneal epithelium thickness profile.

scholarly journals Thickness profiles of the corneal epithelium along the steep and flat meridians of astigmatic corneas after orthokeratology

2020 ◽  
Author(s):  
Jiaqi Zhou ◽  
Feng Xue ◽  
Xingtao Zhou ◽  
Rajeev Krishnan Naidu ◽  
Yishan Qian
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Acuity ◽  
Prospective Study ◽  
Corneal Epithelium ◽  
Fourier Domain ◽  
Corneal Epithelial ◽  
Epithelial Thickness ◽  
Corneal Epithelial Thickness ◽  
A Prospective Study ◽  
Lens Wear

Abstract Background: To investigate the changes in corneal epithelial thickness along the principle meridians of astigmatic corneas after six months of overnight spherical myopic orthokeratology (OK) lens wear. Methods: A prospective study. Fifty-seven subjects with up to 1.50 diopters (D) of corneal toricity wore spherical OK lenses for 6 months. Evaluations of OK lens fit, visual acuity, refractions and corneal toricity (CT) were performed. Fourier-domain optical coherence tomography (FD-OCT) was conducted to measure the corneal epithelial thickness (ET) along the principle meridians of corneal toricity over a diameter of 6mm. The means of △ET of the same diameter at individual meridians (△ETSm and △ETFm) were calculated and compared. Results: Visual acuity and refraction improved significantly after OK lens wear. △ETFm (-4.2±3.4μm) thinned more than △ETSm (-3.4±4.0μm, P=0.027) at 1.5mm in radius. △ETSm thickened more than △ETFm at 2.5mm (△ETSm: 4.1±5.1μm, △ETFm: 2.8±4.2μm, P=0.019) and 3.0mm (△ETSm: 5.0±5.0μm, △ETFm: 3.7±4.9μm, P=0.036).∣△ETSm - △ETFm∣ were significantly correlated with the baseline central CT at 2.0mm, 2.5mm and 3.0mm (2.0mm: r=0.285, P=0.032; 2.5mm: r=0.422, P=0.001; 3.0mm: r=0.239, P=0.027). ∣△ETSm - △ETFm∣was significantly correlated with the baseline peripheral CT at 2.5mm (r=0.299, P=0.028). Conclusions: Overnight wear of spherical OK lenses resulted in differential changes in the thickness profiles of the corneal epithelium between the steep and flat meridians in eyes with corneal toricity.

scholarly journals Orthokeratology in Moderate Myopia: A Study of Predictability and Safety

2020 ◽  
Author(s):  
Kirti Singh ◽  
Mainak Bhattacharyya ◽  
Abhishek Goel ◽  
Ritu Arora ◽  
Nikhil Gotmare ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Contact Lenses ◽  
Corneal Thickness ◽  
Case Series ◽  
Tear Film ◽  
Control Group ◽  
Study Group ◽  
Soft Contact Lenses

Purpose: Literature is relatively silent on safety profile and predictability of orthokeratology lenses in terms of myopia correction and prevention of further progression, especially in semi-tropical countries; this study was designed to fill this gap. Methods: This prospective, intervention case series enrolled 30 eyes of 30 patients with myopia up to –5.5 diopters (D). Patients were randomized into two groups of 15 each; the study group was prescribed overnight orthokeratology (OK) lenses, while the control group used daily wear conventional soft contact lenses. Follow-up examinations were performed after 1 h and 6 h, and then at 1, 7, 15, 30 days, and 4 months post lens wear. Uncorrected visual acuity (UCVA), contrast sensitivity, keratometry, central corneal thickness (CCT), and tear film break up time (TBUT) were evaluated at each follow-up examination. Results: All patients attained a visual acuity of 0.00 Logarithm of the Minimum Angle of Resolution (logMAR) after one week of lens use, which was maintained throughout the study period. While patients allotted to the study group had a gain of 8.1 Snellen lines (UCVA), those in the control group gained 8.9 lines (BCVA) at the end of follow-up period. In the OK group, cornea showed a flattening of 0.8 D (mean keratometry) after single overnight usage of OK lens and overall flattening of 1.2 D compared to baseline, at the end of four months. The change in contrast sensitivity, corneal endothelial specular count, axial length and tear film status was not significant in either group. Conclusion: Orthokeratology is an effective and safe modality to correct moderate myopia in motivated young adults. No side effects were encountered after a short-term follow-up in participants who resided in semi-tropical environments.

scholarly journals Bowman layer transplantation in eyes with progressive advanced keratoconus

2019 ◽  
Vol 12 (4) ◽  
pp. 43-50
Author(s):  
O. G. Oganesyan ◽  
V. R. Getadaryan ◽  
P. V. Makarov ◽  
A. A. Grdikanyan
Keyword(s):  
Visual Acuity ◽  
Contact Lenses ◽  
Corneal Transplantation ◽  
Corneal Stroma ◽  
Functional Safety ◽  
Indication For Surgery ◽  
Corrected Visual Acuity ◽  
Before And After ◽  
Observation Period

Purpose: to study the efficiency of Bowman layer transplantation (BLT) in corneal stroma for the treatment of progressive keratoconus (KC).Material and methods. 30 patients (30 eyes) with progressive KC stages III to IV (according to Amsler — Krumeich classification), underwent BLT into a mid-stromal pocket. At the time of surgery, the patients were 14 to 37 (averagely 26.6 ± 6.2 years). Before and after the surgery, the maximum keratometry index (Kmax) and the corneal thinnest point (CTP) values were determined. Also, we evaluated visual acuity before and after surgery in scleral contact lenses, endothelial cells density (ECD) and the depth of graft location. The indication for surgery was the refusal of corneal transplantation, progression of KC, contraindications for ultraviolet crosslinking or implantation of intracorneal ring segments based on the CTP and Kmax values. The follow-up continued 6 to 36 months (averagely, 26.6 ± 6.0 months).Results. Throughout the observation period, no intra or postoperative complications associated with BLT or deterioration of CTP, Kmax or best corrected visual acuity (BCVA) in scleral lenses were noted.Conclusions. Kmax, CTP and ECD values remaining stable during the follow-up is the evidence of a stabilizing BLT effect on the KC progression. The absence of BCVA decrease in scleral lenses indicates a functional safety of BLT.

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