scholarly journals Comparison of Tomography Suspect Keratoconus Defined by Sirius and Pentacam in a Chinese Cohort

2021 ◽  
Author(s):  
Kang Feng ◽  
Yu Zhang ◽  
Yue-guo Chen
Keyword(s):  
Cohort Study ◽  
False Positive ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Single Center ◽  
Horizontal Diameter ◽  
Peking University ◽  
Chinese Cohort ◽  
Surgical Corrections ◽  
Corneal Diameter

Abstract Purpose: The study is to compare the proportion of tomography suspect keratoconus (TSK) defined by Sirius and Pentacam, and to explore the possible causes of the differences between them in a Chinese cohort.Methods: Single center prospective cohort study. All subjects were selected from the Peking University Third Hospital Ectasia Cornea Disease Cohort Project database, which included myopic patients seeking corneal refractive surgical corrections since the year of 2013. In this study, all cases which were examined by Sirius and Pentacam respectively and have been followed up at least 2 years without abnormalities after laser corneal refractive surgeries (LASEK, FS-LASIK or SMILE). The composition ratio of TSK from Sirius and Pentacam, corneal diameter and thickness, and variables of corneal tomographers between the ‘normal eyes’ and the ‘TSK eyes’ defined by Sirius and Pentacam were compared. Results: To the date of December 31, 2018, total 171 cases (278 eyes) were selected in this study. Total 167 (167/278, 60.1%) eyes were diagnosed of TSK by Sirius, and 203 (203/278, 73.0%) eyes were diagnosed of TSK by Pentacam (P<0.001). The corneal horizontal diameter is 11.40 and 11.60 mm in normal eyes and Sirius-TSK eyes (P<0.001). The corneal horizontal diameter is 11.74 and 11.43 mm in normal eyes and Pentacam-TSK eyes (P<0.001). The central corneal thickness measured by Sirius is 530.1 μm and 518.1 μm (P=0.001) in normal eyes and Sirius-TSK eyes. The central corneal thickness measured by Pentacam is 521.5 μm and 526.6 μm (P=0.102) in normal eyes and Pentacam-TSK eyes. Conclusions: The proportion of TSK eyes diagnosed by Sirius is less than those diagnosed by Pentacam in Chinese. Smaller corneal diameter is liable to be judged as false positive of keratoconus by Pentacam in Chinese compared with Sirius. Thinner corneal thickness is liable to be judged as false positive of keratoconus by Sirius in Chinese compared with Pentacam.

scholarly journals The possible causes for tomography suspect Keratoconus in a Chinese cohort

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kang Feng ◽  
Yu Zhang ◽  
Yue-guo Chen
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Auxiliary Equipment ◽  
Chi Square ◽  
Horizontal Diameter ◽  
Peking University ◽  
Chinese Cohort ◽  
Eye Examination ◽  
Nested Case Control ◽  
Surgical Corrections

Abstract Background To explore the possible causes of tomography suspect keratoconus (TSK) marked by Tomography in screening keratoconus in a Chinese cohort, and the reasonable range of corneal horizontal diameter and thickness for decreasing the proportion of TSK. Methods Nested case-control study from a single center prospective cohort. All subjects were selected from the Peking University Third Hospital Ectasia Cornea Disease Cohort Project database, which included myopic patients seeking corneal refractive surgical corrections since 2013. Demographic information, basic eye examination, and auxiliary equipment examination including refraction, IOL-master, Pentacam, Sirius, and Topolyzer were recorded. In this study, all cases were classified into two groups: TSK group and normal control (NC) group, and all of them were followed up at least 2 years. The former is consisted of those whose screening examinations of tomography are abnormal, the latter is those whose screening examinations are normal. All of them have already been followed up at least 2 years without abnormalities after excimer laser corneal refractive surgeries. Unpaired t tests and Chi-square tests were used to compare the differences of indices from the tomography between the two groups. Results Of 183 TSK eyes (109 patients) and 160 NC eyes (83 patients), the mean age is 28.0 and 26.3 years old respectively. The corneal horizontal diameter is 11.5–11.8 mm in TSK group and 11.8–12.0 mm in NC group. The central corneal thickness is nearly 520 μm in the former and 550 μm in the latter. For Sirius, the TSK ratio of indices of SIf and SIb is 41.5 and 39.9% respectively in TSK group. For Pentacam, the TSK ratio of index IHD is 59.0% and “final D” is 72.7%. Conclusions Corneal horizontal diameter and central corneal thickness have great influences on the results of corneal tomography in detecting the suspect keratoconus.

scholarly journals Central corneal thickness changes and horizontal corneal diameter in premature infants

Medicine ◽  
2018 ◽  
Vol 97 (48) ◽  
pp. e13357
Author(s):  
May May Choo ◽  
Choo Mee Yeong ◽  
John R. Grigg ◽  
Nurliza Khaliddin ◽  
Azida Juana Kadir ◽  
...  
Keyword(s):  
Premature Infants ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Corneal Diameter

scholarly journals Central corneal thickness and corneal diameter in premature infants

2005 ◽  
Vol 83 (6) ◽  
pp. 751-753 ◽  
Author(s):  
Caitriona Kirwan ◽  
Michael O'Keefe ◽  
Susan Fitzsimon
Keyword(s):  
Premature Infants ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Corneal Diameter

scholarly journals The Study of Ocular Parameters in Low to Moderate Myopic Chinese Children Age Between Eight to Eighteen-Year-Old

2021 ◽  
Author(s):  
Zhengxuan Li ◽  
Lu Sun ◽  
Hongxin Song
Keyword(s):  
Retrospective Study ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Corneal Endothelial Cell ◽  
Spherical Equivalent ◽  
Corneal Endothelial Cell Density ◽  
The Mean ◽  
Beijing China ◽  
Corneal Diameter

Abstract Purpose: The primary aim of this study was to analyze the distribution of ocular parameters of children aged from eight to eighteen-year-old with low to moderate myopia as well as offer useful information for the design and clinical fitting of ortho-k lens in China.Methods: In this retrospective study, we collected data of 300 subjects (600 eyes) age between eight to eighteen-year-old from the myopic control outpatient clinic at Beijing Tongren Hospital, Beijing, China. The spherical equivalent (SE), axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), corneal endothelial cell density (CECD)，corneal diameter (CD), simulated K (Sim K) were collected from all the subjects and analyzed. Results: The mean of SE for all subjects was -3.12 ± 1.21D, the median was -3.16D. The mean of AL for all subjects was 24.72 ± 0.83 mm, the median was 24.72 mm. The mean of CCT for all subjects was 537.8 ± 29.82 μm, the median was 538.17 μm. The mean of CECD for all subjects was 3340.3 ± 352.6 cells/mm2, the median was 3357.77 cells/mm2. The mean of ACD for all subjects was 3.71 ± 0.21 mm, the median was 3.69 mm. The mean of CD for all subjects was 12.15 ± 1.67 mm, the median was 12.05 mm. The mean of flat K was 42.80 ± 1.29, the median was 42.81. The mean of steep K was 43.76 ± 1.37, the median was 43.76.Conclusions: This study provided the distribution of ocular parameters to offer useful information for diagnosis of many eye conditions. Meanwhile, the distribution of ocular parameters of children aged from eight to eighteen-year-old with low to moderate myopia is beneficial to make the application of overnight orthokeratology lens more appropriate and effective.

scholarly journals Comparison of Repeatability and Agreement between Swept-Source Optical Biometry and Dual-Scheimpflug Topography

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Soyeon Jung ◽  
Hee Seung Chin ◽  
Na Rae Kim ◽  
Kang Won Lee ◽  
Ji Won Jung
Keyword(s):  
Prediction Error ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Swept Source ◽  
Good Repeatability ◽  
Optical Biometer ◽  
Corneal Diameter ◽  
High Repeatability ◽  
Iolmaster 700

Purpose. To assess the repeatability and agreement of parameters obtained with two biometers and to compare the predictability. Methods. Biometry was performed on 101 eyes with cataract using the IOLMaster 700 and the Galilei G6. Three measurements were obtained per eye with each device, and repeatability was evaluated. The axial length (AL), anterior chamber depth (ACD), keratometry (K), white-to-white (WTW) corneal diameter, central corneal thickness (CCT), and lens thickness (LT) were measured and postoperative predictability was compared. Results. Measurements could not be obtained with the IOLMaster 700 in one eye and in seven eyes with the Galilei G6 due to dense cataract. Both the IOLMaster 700 and Galilei G6 showed good repeatability, although the IOLMaster 700 showed better repeatability than the Galilei G6. There were no statistically significant differences in AL, ACD, steepest K, WTW, and LT (P>0.050), although flattest K, mean K, and CCT differed (P<0.050). The proportion of eyes with an absolute prediction error within 0.5 D was 85.0% for the IOLMaster 700 and was 80.0% for the Galilei G6 based on the SRK/T formula. Conclusions. Two biometers showed high repeatability and relatively good agreements. The swept-source optical biometer demonstrated better repeatability, penetration, and an overall lower prediction error.

scholarly journals Central corneal thickness and corneal diameter in preterm and term newborns and preterm neonates at term

2019 ◽  
Vol 67 (10) ◽  
pp. 1575
Author(s):  
Anurag Shandil ◽  
Prateek Sehrawat ◽  
Sarita Beri ◽  
Rajiv Garg ◽  
Vikram Datta
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Preterm Neonates ◽  
Term Newborns ◽  
Corneal Diameter

scholarly journals Refractive Stability and Ocular Biometric Changes After Customized LASEK for Correction of Myopia; 8 Years Follow up

2020 ◽  
Author(s):  
Seyed Javad Hashemian ◽  
Acieh Es'haghi ◽  
Hossein Aghaei ◽  
Leila Ghiasian ◽  
Mohammad Ebrahim Jafari ◽  
...  
Keyword(s):  
Cohort Study ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Spherical Equivalent ◽  
Biometric Data ◽  
Biometric Parameters ◽  
Refractive Outcomes

Abstract BACKGROUND: To assess long-term Visual and refractive stability and ocular biometric changes in low to moderate myopic subjects treated by customized LASEK. METHODS: Seventy eyes of 35 patients were treated by customized LASEK for correction of less than 6 diopter myopia in this cohort study. Uncorrected visual acuities (UCVA) and distance corrected visual acuities (DCVA), keratometry values and ocular biometric data by Lenstar LS900 including anterior chamber depth (ACD), aqueous depth, central corneal thickness(CCT),lens thickness(LT) and axial length(AL) were evaluated pre and 8 years postoperatively. RESULTS: Mean pre-operative spherical equivalent was -3.99 ±1.38 diopter (D) that improved to 0.01 ±0.27 D and -0.10 ±0.31 D, 6 months and 8 years postoperative respectively. Mean pachymetry, flat, steep and mean keratometry values increased significantly from 6 months to 8 years postoperative. Although, these changes had no significant effect on visual outcomes and subjective refraction. ACD decreased and LT increased significantly over 8 years follow-up in comparison with preoperative values. The change in AL was not significant at 8 years follow up.CONCLUSIONS: The long-term visual and refractive outcomes of customized LASEK in correction of low to moderate myopia were stable and predictable, although changes in ocular biometric parameters have occurred.

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