Decreased Central and Limbal Epithelium Thickness After Corneal Crosslinking Evaluated by Anterior Segment Optic Coherence Tomography

Mapping Intimacies ◽

10.21203/rs.3.rs-329553/v1 ◽

2021 ◽

Author(s):

HANDE GÜÇLÜ ◽

İRFAN AKARAY ◽

ÖZLEM KAYA

Keyword(s):

Anterior Segment ◽

Treated Group ◽

Untreated Group ◽

Cross Linking ◽

Optic Coherence Tomography ◽

Optical Coherence ◽

Epithelial Thickness ◽

Limbal Epithelium ◽

Significant Difference ◽

Epithelium Thickness

Abstract Aim: To Investigate the central cornea, limbal epithelium thickness and stroma thickness after corneal cross-linking by Anterior Segment Optical Coherence Tomography (AS-OCT) and Scheimpflug topography.Methods: Fifteen keratoconus patients treated with cross-linking(CXL) and fifteen untreated keratoconus patients was included to the study. Corneal central, limbal epithelial, stromal and total thickness with was analyzed by using Anterior Segment Optical Coherence Topography (AS-OCT) and keratometric values were analyzed by Scheimpflug topography.Results: There was a statisticallly significant difference between treated and untreated keratoconus patients according to limbal epithelial thickness (LET). Limbal epithelial thickness was 30.7 ± 5.5µm in the treated keratoconus patients and 45.6 ± 11.5µm in the untreated patients (p = 0.04). Central corneal epithelial thickness (CCET) was 38.27±3.5 in the treated group and 60.8 ± 10.9µm in the untreated group. There was a statistically signifficant difference the between two groups (p=0.01). The posterior astigmatism value was 0.7 ± 0.3D in the treated group and 0.9 ± 0.5D in untreated group by Scheimpflug topography (p=0.03).Conclusion: Our study have shown that the central corneal epithelium and limbal epithelium were significantly thinned as a result of corneal cross-linking. Corneal posterior astigmatism value decreased among the keratometric values. Epithelial thickness and limbal thickness alterations detected with Ant-OCT could be useful for monitorizing the keratoconus patients treated with crosslinking and could show the effectivity of the treatment.

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

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v9ispl1.1285 ◽

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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Comparison of Anterior Ocular Biometric Measurements Using Swept-Source and Time-Domain Optical Coherence Tomography

Journal of Ophthalmology ◽

10.1155/2020/9739878 ◽

2020 ◽

Vol 2020 ◽

pp. 1-6

Author(s):

Sisi Chen ◽

Rongrong Gao ◽

Colm McAlinden ◽

Junming Ye ◽

Yiran Wang ◽

...

Keyword(s):

Time Domain ◽

Corneal Thickness ◽

Intraclass Correlation ◽

Anterior Segment ◽

Anterior Chamber Depth ◽

Correlation Coefficients ◽

Random Order ◽

Optical Coherence ◽

Swept Source ◽

Significant Difference

Purpose. To compare central corneal thickness (CCT), aqueous depth (AQD), and anterior chamber depth (ACD) measurements using the swept-source (CASIA SS-1000, Tomey, Japan) and time-domain (Visante, Carl Zeiss Meditec, USA) anterior segment optical coherence tomographers (OCT) in normal eyes. Methods. Sixty-eight eyes of 68 subjects were included. Three consecutive scans of each subject were obtained using both devices in a random order by one experienced operator. Standard deviation (Sw), coefficient of repeatability (CoR), coefficients of variation (CoV), and intraclass correlation coefficients (ICC) were used to evaluate the intraoperator repeatability. Agreement was assessed using the Bland–Altman plots and 95% limits of agreement (LoA). Results. All measurements of the swept-source OCT (SS-OCT) and time-domain OCT (TD-OCT) showed high repeatability with low CoR (CCT: 2.34 μm and 6.16 μm; AQD: 0.05 mm and 0.09 mm; ACD: 0.06 mm and 0.09 mm), low CoV (CCT: 0.16% and 0.42%; AQD: 0.61% and 0.97%; ACD: 0.53% and 0.83%), and high ICC (>0.98). The mean CCT with SS-OCT was slightly thicker than the results with TD-OCT (difference = 4.55 ± 2.62 μm, P<0.001). There was no statistically significant difference in AQD or ACD measurements between the two devices (0.01 ± 0.05 mm, P=0.111; 0.02 ± 0.05 mm, P=0.022, respectively). The 95% LoA between the SS-OCT and TD-OCT were −0.59 to 9.69 μm for CCT, −0.10 to 0.12 mm for AQD, and −0.09 to 0.12 mm for ACD. Conclusions. High levels of repeatability and agreement were found between the two devices for all three parameters, suggesting interchangeability. SS-OCT demonstrated superior repeatability compared with TD-OCT.

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Optical Coherence Tomography Reveals New Insights into the Accommodation Mechanism

Journal of Ophthalmology ◽

10.1155/2015/510459 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5 ◽

Cited By ~ 5

Author(s):

Mahmoud Mohamed Farouk ◽

Takeshi Naito ◽

Kayo Shinomiya ◽

Hiroshi Eguchi ◽

Khulood Mohammed Sayed ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Outcome Measures ◽

Anterior Segment ◽

Case Series ◽

Optical Coherence ◽

Anterior Pole ◽

Forward Movement ◽

Anterior Segment Oct ◽

Lens Thickness ◽

Significant Difference

Purpose. To evaluate the movement of the anterior and posterior lens poles during naturally stimulated accommodation in children using anterior segment optical coherence tomography (OCT).Methods. This is a prospective, observational, noncomparative case series including 18 eyes of nine children. Analysis of the anterior segment in the accommodated and unaccommodated state (with cycloplegia) was done using anterior segment OCT. The main outcome measures were the position of the anterior and posterior lens poles (in relation to the cornea) and lens thickness (LT).Results. A Statistically significant forward movement of the anterior lens pole and backward movement of the posterior lens pole with an increase in LT were found during accommodation (P<0.001). There was no significant difference between the degree of movement of the anterior lens pole and the posterior lens pole during accommodation (P=0.944).Conclusions. Anterior segment OCT provides a rapid noncontact method for studying accommodation in children. The backward movement of the posterior lens pole during accommodation nearly equals the forward movement of its anterior pole. These data minimize the theoretical hydraulic effect of the vitreous during accommodation, adding more support to the capsular theory of Helmholtz.

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Optical Coherence Tomography Angiography Imaging to monitor Anti-VEGF treatment of Corneal Vascularization in a Rabbit Model

Scientific Reports ◽

10.1038/s41598-019-54171-5 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Kavya Devarajan ◽

Hon Shing Ong ◽

Nyein C. Lwin ◽

Jacqueline Chua ◽

Leopold Schmetterer ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Imaging Technique ◽

Anterior Segment ◽

Rabbit Model ◽

Saline Group ◽

Optical Coherence ◽

Conjunctival Injection ◽

Anti Vegf ◽

Significant Difference

AbstractOptical coherence tomography angiography (OCTA) is a well-established non-invasive retinal vascular imaging technique. It has been recently adapted to image the anterior segment and has shown good potential to image corneal vascularisation. The purpose of the study is to evaluate the usefulness of OCTA to monitor regression of corneal vessels following anti-VEGF (vascular endothelial growth factor) treatment using a previously established corneal vascularisation rabbit model. The regression of vessels following the treatment with aflibercept and ranibizumab anti-VEGFs using both topical instillation and sub-conjunctival injection was quantified using OCTA and compared with ICGA (indocyanine green angiography). Overall vessel density measurements using OCTA showed good correlation (r = 0.988, p < 0.001) with ICGA, with no significant difference between the two treatment groups (p = 0.795). It was also shown that OCTA provided good repeatability outcomes of the quantitative measurements. Using Bland-Altman plots, vessel growth density values between anti-VEGF treatments were compared to control saline group. It was observed that aflibercept provided longer lasting effect than ranibizumab. We also observed that in both drugs, the topical route of administration topical provided longer regression outcomes compared to one-time sub-conjunctival injection. Thereby, with this pilot study, it was demonstrated that OCTA is a reliable imaging technique to follow-up and monitor corneal vascularisation and its treatment quantitatively.

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Accelerated Corneal Collagen Cross-Linking Using Topography-Guided UV-A Energy Emission: Preliminary Clinical and Morphological Outcomes

Journal of Ophthalmology ◽

10.1155/2016/2031031 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 14

Author(s):

Cosimo Mazzotta ◽

Antonio Moramarco ◽

Claudio Traversi ◽

Stefano Baiocchi ◽

Alfonso Iovieno ◽

...

Keyword(s):

Anterior Segment ◽

Case Series ◽

Cross Linking ◽

Optic Coherence Tomography ◽

Retrospective Case ◽

One Year ◽

Coma Aberration ◽

Topographic Astigmatism ◽

Corneal Collagen

Purpose. To assess the clinical and morphological outcomes of topography-guided accelerated corneal cross-linking. Design. Retrospective case series. Methods. 21 eyes of 20 patients with progressive keratoconus were enrolled. All patients underwent accelerated cross-linking using an ultraviolet-A (UVA) exposure with an energy release varying from 7.2 J/cm2 up to 15 J/cm2, according to the topographic corneal curvature. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, topography, in vivo confocal microscopy (IVCM), and anterior segment optic coherence tomography (AS-OCT) were evaluated preoperatively and at the 1, 3, 6, and 12 months postoperatively. Results. 12 months after surgery UDVA and CDVA did not significantly vary from preoperative values. The average topographic astigmatism decreased from -4.61±0.74 diopters (D) to -3.20±0.81 D and coma aberration improved from 0.95 ± 0.03 μm to 0.88 ± 0.04 μm after surgery. AS-OCT and IVCM documented differential effects on the treated areas using different energies doses. The depths of demarcation line and keratocyte apoptosis were assessed. Conclusions. Preliminary results show correspondence between the energy dose applied and the microstructural stromal changes induced by the cross-linking at various depths in different areas of treated cornea. One year after surgery a significant reduction in the topographic astigmatism and comatic aberration was detected. None of the patients developed significant complications.

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Visibility and Depth of the Stromal Demarcation Line After Corneal Collagen Cross-Linking Using Anterior Segment Optical Coherence Tomography

Cornea ◽

10.1097/ico.0000000000001493 ◽

2018 ◽

Vol 37 (5) ◽

pp. 567-573 ◽

Cited By ~ 3

Author(s):

Louis Lhuillier ◽

Cedric Ghetemme ◽

Mathilde Boiché ◽

Rekia Yahia ◽

Naila Houmad ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Anterior Segment ◽

Cross Linking ◽

Optical Coherence ◽

Demarcation Line ◽

Collagen Cross Linking ◽

Corneal Collagen

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A pilot study of scleral thickness in central serous chorioretinopathy using anterior segment optical coherence tomography

Scientific Reports ◽

10.1038/s41598-021-85229-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yun Ji Lee ◽

Yeon Jeong Lee ◽

Jae Yeon Lee ◽

Suhwan Lee

Keyword(s):

Optical Coherence Tomography ◽

Central Serous Chorioretinopathy ◽

Anterior Segment ◽

Venous Drainage ◽

Enhanced Depth Imaging ◽

Control Group ◽

Study Group ◽

Optical Coherence ◽

Swept Source ◽

Significant Difference

AbstractThe aim of this study is to compare the scleral thickness of central serous chorioretinopathy (CSC) eyes with controls using anterior segment optical coherence tomography (AS OCT). This prospective case control study included 15 patients (15 eyes) with CSC and 15 age and gender matched healthy subjects. All subjects underwent spectral domain OCT with enhanced depth imaging and swept source AS OCT of temporal sclera. We investigated difference in scleral thickness between the two groups and relationship between choroidal and scleral thickness. Among the 15 eyes in the study group, 1 eye had acute CSC, 4 had recurrent CSC, 7 had inactive CSC, and 3 had chronic CSC. There was no significant difference in terms of age, gender, axial length and spherical equivalent between the two groups. The choroidal and scleral thickness of the study group were significantly greater than those of the control group (P < 0.001, P = 0.034). Choroidal thickness was positively correlated with scleral thickness (P = 0.031). A thick sclera along with a thick choroid were demonstrated in CSC eyes using AS OCT. Scleral characteristics might be involved in the pathogenesis of CSC by affecting outflow resistance of venous drainage in choroidal circulation.

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