scholarly journals Repeatability and comparative study of corneal thickness using the Visante™ OCT, OCT II and Orbscan II™

2012 ◽  
Vol 2 (1) ◽  
pp. 4
Author(s):  
Jyotsna Maram ◽  
Luigina Sorbara ◽  
Trefford Simpson
Keyword(s):  
Corneal Thickness ◽  
Anterior Segment ◽  
Correlation Coefficients ◽  
Normal Sample ◽  
Horizontal Meridian ◽  
Epithelial Thickness ◽  
Good Repeatability ◽  
Anterior Segment Imaging ◽  
Orbscan Ii ◽  
Healthy Participants

The first purpose of this study was to measure the repeatability the VisanteTM Optical coherence tomographer (OCT) in a normal sample. The second was to compare corneal thickness measured with the VisanteTM OCT to the Zeiss-Humphrey OCT II (model II, Carl Zeiss Meditec) adapted for anterior segment imaging and to the Orbscan IITM (Bausch and Lomb). Fifteen healthy participants were recruited. At the Day 1 visit, the epithelial and total corneal thickness across the central 10 mm of the horizontal meridian was measured using the OCT II and the VisanteTM OCT. Only total corneal thickness across the central 10 mm of the horizontal meridian was measured using the Orbscan II. These measurements were repeated on Day 2. Mean central corneal and epithelial thickness using the Visante™ OCT at the apex of the cornea was 536±27 mm and 55±2.3 mm. Mean corneal and epithelial thickness using OCT II at the apex was 520±25 mm and 56±4.9 mm. Mean total corneal thickness measured with the Orbscan II was 609±29 mm. The coefficient of repeatability (COR) ranged from ±7.71 to ±8.98 mm for total corneal thickness and from ±8.72 to ±9.92 mm for epithelial thickness. Correlation coefficients of concordance (CCC’s) were high for total corneal thickness for test-retest differences ranging from 0.97 to 0.99, CCCs for epithelial thickness showed moderate concordance for both the instruments. There is good repeatability of corneal and epithelial thickness using each OCT for test-retest differences compared to the between instrument repeatability. Measurements of epithelial thickness were less robust.

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

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.

scholarly journals Swept Source Optical Coherence Tomography Analysis of the Selected Eye’s Anterior Segment Parameters

2021 ◽  
Vol 10 (5) ◽  
pp. 1094
Author(s):  
Michał Dembski ◽  
Anna Nowińska ◽  
Klaudia Ulfik-Dembska ◽  
Edward Wylęgała
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Swept Source ◽  
Iridocorneal Angle ◽  
Glaucoma Diagnosis ◽  
Good Repeatability ◽  
Anterior Segment Parameters ◽  
Important Marker

Background: The present study determined the mean reference values of the anterior segment parameters of the selected eye using swept source optical coherence tomography (SS-OCT) in healthy Caucasian participants. Methods: A total of 166 volunteers (age 54–79 years), women (n = 92) and men (n = 74), were analyzed. One eye of each subject was randomly selected for anterior segment imaging. The anterior segment of the eye was scanned with CASIA2. The analyzed anterior segment parameters were divided into three groups, namely parameters of the cornea, lens, and angle. Results: The OCT (e.g., Ks, Kf, pKf, pKs, and central corneal thickness) and Fourier parameters of the cornea were significantly different between females and males. The iridocorneal angle was the smallest in the upper quadrant for all distance from the apex of the angle (250, 500, and 750 µm). Conclusions: Therefore, SS-OCT enables the analysis of parameters of the cornea, anterior chamber, lens, and iridocorneal angle, highlighting its clinical utility. Sex-specific differences in the analyzed parameters should be taken into account during the diagnosis of corneal diseases. The configuration of the filtration angle is an important marker during glaucoma diagnosis and drainage implant surgery. Measurements with CASIA 2is characterized by very good repeatability.

scholarly journals Repeatability of corneal and epithelial thickness measurements with anterior segment optical coherence tomography in keratoconus

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0248350
Author(s):  
Ye Li ◽  
Akilesh Gokul ◽  
Charles McGhee ◽  
Mohammed Ziaei
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Intraclass Correlation ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Epithelial Thickness ◽  
History Of ◽  
Group A ◽  
Temporal Aspect ◽  
Group B

Purpose To investigate the repeatability in corneal thickness (CT) and epithelial thickness (ET) measurements using spectral domain anterior segment optical coherence tomography (AS-OCT, REVO NX, Optopol) in keratoconus, and examine the effect of corneal crosslinking (CXL) on repeatability. Methods A cross-sectional study of 259 eyes of 212 patients with keratoconus attending the corneal disease clinic at a university hospital tertiary referral center were enrolled. Two groups were analysed: eyes with no prior history of CXL (Group A) and eyes with prior CXL (Group B). Repeatability of measurements was assessed using the intraclass correlation coefficient (ICC) and coefficient of variation (CV). Results In Group A, central corneal thickness (CCT) was 472.18 ± 45.41μm, and the ET was found to be the thinnest in the inferior-temporal aspect at 51.79 ± 5.97μm and thickest at the superior-nasal aspect at 56.07 ± 5.70μm. In Group B, CCT was 465.11± 42.28μm, and the ET was the thinnest at the inferior-temporal aspect at 50.63 ± 5.52μm and thickest at the superior aspect at 56.80 ± 6.39μm. When evaluating CT measurements, ICC was above 0.86 and 0.83 for Group A and Group B respectively. When evaluating ET measurements, ICC was above 0.82 for both groups. CXL had no statistically significant impact on the repeatability of measurements. Conclusions AS-OCT provides repeatable CT and ET measurements in the central and peripheral cornea in patients with keratoconus. Repeatability is not affected by a history of CXL.

Agreement among 3 Methods to Measure Corneal Thickness: Ultrasound Pachymetry, Orbscan II, and Visante Anterior Segment Optical Coherence Tomography

Ophthalmology ◽  
2007 ◽  
Vol 114 (10) ◽  
pp. 1842-1847.e2 ◽  
Author(s):  
Emmy Y.M. Li ◽  
Shaheeda Mohamed ◽  
Christopher K.S. Leung ◽  
Srinivas K. Rao ◽  
Arthur C.K. Cheng ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Ultrasound Pachymetry ◽  
Orbscan Ii

Effects of topical antiglaucomatous medications on central corneal epithelial thickness by anterior segment optical coherence tomography

2020 ◽  
Vol 30 (6) ◽  
pp. 1519-1524
Author(s):  
Emine Doğan ◽  
Burçin Köklü Çakır ◽  
Nilgün Özkan Aksoy ◽  
Erkan Celik ◽  
Ünal Erkorkmaz
Keyword(s):  
Optical Coherence Tomography ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Tear Film ◽  
Optical Coherence ◽  
Corneal Epithelial ◽  
Duration Of Therapy ◽  
Epithelial Thickness ◽  
Corneal Epithelial Thickness

Purpose: To evaluate the effect of topical antiglaucomatous medications on central corneal epithelial thickness measured by anterior segment optical coherence tomography. Materials and methods: A total of 153 eyes of 153 patients using topical antiglaucomatous medications and 110 eyes of 110 control subjects were enrolled. Glaucoma type, duration of therapy, the number of drugs, and drops/day were noted in the patient group. Patients and control subjects underwent ocular examinations including Schirmer test, slit lamp examination for tear film break-up time, and anterior segment optical coherence tomography for central corneal thickness and central corneal epithelial thickness. Central corneal epithelial thickness and other data were evaluated separately with regard to glaucoma type, duration of therapy, the number of drops, and drugs in the patient group. Results: The mean ages of the patients and controls were 60.1 ± 10.8 and 58.7 ± 11.2 years, respectively. The groups were similar with regard to mean age and gender (p = 0.058, p = 0.734, respectively). The median (interquartile range) central corneal thickness was 536 (54) µm in patients and 552 (53) µm in controls (p = 0.011). The median (interquartile range) central corneal epithelial thickness of patients and controls were 56 (4) µm and 60 (8) µm, respectively (p < 0.001). The median (interquartile range) tear film break-up time and Schirmer were 12 (6) s and 10 (8) mm in patients and 16 (2) s and 18 (4) mm in controls, respectively (p < 0.001, p < 0.001). In patient group, there was no significant difference in the median central corneal thickness, central corneal epithelial thickness, and tear film break-up time in terms of glaucoma type, duration of therapy, the number of drugs, and the number of daily drops. Only the median Schirmer test was found to be statistically lower in terms of number of daily eye drops (p = 0.039). Conclusion: Using topical antiglaucomatous medications seems to affect the central corneal epithelial thickness in glaucoma patients. Central corneal epithelial thickness was thinner in glaucoma patients than controls. Anterior segment optical coherence tomography might be helpful to evaluate the effect of antiglaucomatous medications on central corneal epithelial thickness during treatment.

scholarly journals Comparison of central corneal thickness measurements with three different optical devices

2021 ◽  
Vol 13 ◽  
pp. 251584142199563
Author(s):  
Mehmet Barış Üçer ◽  
Erdinç Bozkurt
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Correlation Coefficients ◽  
Limits Of Agreement ◽  
The Mean ◽  
Mean Differences ◽  
High Level ◽  
Thickness Measurements

Purpose: The purpose of this study was to compare and evaluate the agreement of central corneal thickness (CCT) values obtained with three different devices working according to optical principle in healthy eyes. Methods: 60 eyes of 60 individuals (30 men and 30 women) were enrolled in this study. CCT measurements performed with Scheimpflug–Placido topographer (Sirius), spectral-domain optical coherence tomography (RTVue) with an anterior segment module, and optical biometer (AL-Scan) were compared. Bland–Altman analysis was used to demonstrate agreement between methods. Results: The mean age was 30.07 ± 7.313 years (range, 18–47 years). The mean CCT values obtained by RTVue, Sirius, and AL-Scan were 518.25 ± 36.38 µm, 526.08 ± 36.33 µm, and 513.50 ± 39.09 µm, respectively. The mean differences in CCT were 7.83 ± 14.15 µm between Sirius and RTVue, 12.58 ± 11.87 µm between Sirius and AL-Scan, and 4.75 ± 4.50 µm between RTVue and AL-Scan. The mean CCT was statistically different among the three groups ( p < 0.05). All three modalities of CCT measurements correlated closely with each other, with Pearson’s correlation coefficients ranging from 0.924 to 0.961. The 95% limits of agreement were −19.90 to 35.56 µm between Sirius and RTVue, −10.69 to 35.85 µm between Sirius and AL-Scan, and −4.07 to 13.58 µm between RTVue and AL-Scan. Conclusion: Different results could be obtained through different noncontact devices in CCT measurements. Although the measurement values obtained by these devices show a high level of correlation, it would be a more correct approach to not use them directly interchangeably in clinical practice. Evaluation and follow-up of CCT should be performed using the same device.

scholarly journals Accuracy and reliability of measurements obtained with a noncontact tono-pachymeter for clinical use in mass screening

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jinho Lee ◽  
Hyuk Jin Choi
Keyword(s):  
Open Angle Glaucoma ◽  
Pearson Correlation ◽  
Corneal Thickness ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Strongly Correlated ◽  
Altman Analysis ◽  
Applanation Tonometer ◽  
Cautious Interpretation ◽  
Healthy Participants

AbstractWe evaluated the reliability and accuracy of the noncontact CT-1P tonopachymeter (Topcon, Japan) in terms of intraocular pressure (IOP) and central corneal thickness (CCT). One hundred sixty-three healthy participants and 33 patients with open angle glaucoma were enrolled. IOPs were measured by CT-1P (T-IOP) and Goldmann applanation tonometer (G-IOP), and CCTs were measured by the CT-1P (T-CCT) and an ultrasound pachymeter (US-CCT). Both CCT instrument-adjusted (T-IOP-C) and unadjusted T-IOPs (T-IOP-NC) were included. Pearson correlation coefficients and biases assessed with Bland–Altman analysis with 95% confidence interval (CI) were calculated for reliability evaluation. Intrasession repeatability was excellent for both T-IOP (intraclass correlation coefficient [ICC] 0.91) and T-CCT (ICC 0.98). Intersession reproducibility was also excellent for T-CCT (ICC 0.94). T-IOP-NC and T-IOP-C both showed significant correlations with G-IOP (r = 0.801, P  <  0.001 and r = 0.658, P  < 0.001, respectively). T-CCT was also strongly correlated with US-CCT (r = 0.958; P  < 0.001). T-IOP-NC and T-IOP-C both showed a positive bias (1.37 mmHg, 95% CI [1.14, 1.61] and 2.77 mmHg, 95% CI [2.49, 3.05], respectively). T-CCT showed a negative bias of − 17.3 µm (95% CI [−18.8, − 15.8]). With cautious interpretation, the CT-1P may offer good feasibility for IOP and CCT measurement in screening centers.

scholarly journals Epithelial and stromal remodelling following femtosecond laser–assisted stromal lenticule addition keratoplasty (SLAK) for keratoconus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mario Nubile ◽  
Niccolò Salgari ◽  
Jodhbir S. Mehta ◽  
Roberta Calienno ◽  
Emanuele Erroi ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Observational Study ◽  
Femtosecond Laser ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Corneal Epithelial ◽  
Cadaveric Donor ◽  
Epithelial Thickness ◽  
Corneal Epithelial Thickness

AbstractThe purpose of this study was to evaluate corneal epithelium and stromal remodelling with anterior segment optical coherence tomography in patients who have undergone stromal lenticule addition keratoplasty (SLAK) for advanced keratoconus. This was a prospective non-comparative observational study. Fifteen eyes of 15 patients with advanced keratoconus underwent implantation with a cadaveric, donor negative meniscus-shaped intrastromal lenticule, produced with a femtosecond laser, into a stromal pocket dissected in the recipient cornea at a depth of 120 μm. Simulated keratometry, central corneal thickness (CTT), corneal thinnest point (CTP), central epithelial thickness (CET), central and peripheral lenticule thickness, anterior and posterior stromal thickness were measured. Regional central corneal epithelial thickness (CET) and variations in the inner annular area (IAT) and outer annular area (OAT) were also analysed. All parameters were measured preoperatively and 1, 3, and 6 months postoperatively. The average anterior Sim-k decreased from 59.63 ± 7.58 preoperatively to 57.19 ± 6.33 D 6 months postoperatively. CCT, CTP, CET, and OAT increased and IAT decreased significantly after 1 month. All parameters appeared unchanged at 6-months except that of OAT that further increased. Lenticule thickness was stable. In conclusion we observed that SLAK reshapes the cornea by central flattening with stromal thickening and epithelial thickness restoration.

Decreased epithelial to corneal thickness ratio in healthy fellow eyes of patients with unilateral bullous keratopathy

2019 ◽  
Vol 104 (2) ◽  
pp. 230-234
Author(s):  
Alexei N Kulikov ◽  
Dmitrii S Maltsev ◽  
Elena V Kudryashova ◽  
Maria A Burnasheva
Keyword(s):  
Corneal Thickness ◽  
Anterior Segment ◽  
Central Area ◽  
Bullous Keratopathy ◽  
Specular Microscopy ◽  
Healthy Individuals ◽  
Epithelial Thickness ◽  
The Relationship ◽  
Subclinical Dysfunction ◽  
Fellow Eyes

PurposeTo study the relationship between epithelial thickness (ET) and corneal thickness (CT) in healthy fellow eyes of patients with unilateral bullous keratopathy (BKP) and healthy subjects.MethodsSeventeen BKP patients (nine males, eight females, 73.2±10.4 years) and 40 healthy individuals (20 males, 20 females, 69.5±9.8 years) were included. All participants received anterior segment optical coherence tomography and specular microscopy with calculation of endothelial cell density. ET, CT, stromal thickness and ET-to-CT ratio were defined automatically (within 2 mm central area). Central epithelial thickness (CET) and central corneal thickness (CCT) were measured manually at the corneal centre and stromal thickness and CET-to-CCT ratio were calculated.ResultsIn healthy fellow eyes of BKP patients compared with eyes of healthy individuals ET was statistically significantly lower (p<0.001) while CT was statistically significantly higher (by 28.9 and 30.9 µm in 2 mm zone and corneal centre, respectively). Both 2 mm ET-to-CT ratio (0.091±0.01 and 0.10±0.004, respectively [p<0.001]) and CET-to-CCT ratio (0.083±0.006 and 0.97±0.005, respectively [p<0.0001]) were statistically significantly lower in healthy fellow eyes of BKP patients compared with eyes of healthy individuals. To identify healthy fellow eyes of BKP patients, area under curve for CET-to-CCT ratio and CET was 0.94 and 0.80, respectively (p=0.01), and for 2 mm ET-to-CT ratio and 2 mm ET was 0.91 and 0.80, respectively (p=0.03).ConclusionDecreased СET-to-СCT ratio resulting from simultaneous epithelial thinning and stromal thickening without significant corneal thickening indicates subclinical dysfunction of corneal endothelium in healthy fellow eyes in unilateral BKP patients.

scholarly journals The role of epithelial thickness mapping in corneal refractive surgery

2021 ◽  
Vol 8 (3) ◽  
pp. 196-201
Author(s):  
Aleksandra Wlaź ◽  
Barbara Czarnota-Nowakowska ◽  
Joanna Wierzbowska
Keyword(s):  
Refractive Surgery ◽  
New Technologies ◽  
Anterior Segment ◽  
Efficacy And Safety ◽  
Significant Progress ◽  
Corneal Epithelial ◽  
Epithelial Thickness ◽  
Corneal Refractive Surgery ◽  
Anterior Segment Imaging

Refractive surgery has stimulated significant progress in anterior segment imaging. Knowledge of epithelial thickness profile considerably increases the efficacy and safety of refractive procedures. This review aims to present new technologies evaluating corneal epithelial thickness and the most important clinical applications in the field of corneal refractive surgery.

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