scholarly journals Measurement and Analysis of Central Corneal Thickness at Different Postnatal Stages in Chinese Premature Infants

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Chenyi Liu ◽  
Hanfei Wu ◽  
Jimeng Lao ◽  
Sulan Wu ◽  
Xiaoqiong Xu ◽  
...  

Purpose. The objective of this study was to evaluate central corneal thickness (CCT) in Chinese premature infants at different postnatal stages to study the peak point and analyze influential factors on CCT development. Methods. This was a cross-sectional study of premature infants. Initial CCT measurement was taken at 34 weeks of gestational age (GA) and at intervals until 88 weeks of postmenstrual age (PMA) was reached. The comparison and correlation analysis were carried out to access the association of CCT with gender, birth weight (BW), GA, and retinopathy of prematurity (ROP) for each PMA. The premature infants were divided into the thick CCT group and the thin CCT group according to the average CCT at 40 w. And the difference in CCT between the two groups at subsequent 52 w and 64 w was compared. Results. A total of 1726 premature infants (3463 measurements) with an average of 2.21 ± 1.57 measurements were included in this study. The CCT decreased from 34 w GA to 52 w PMA (R = 92.36, P<0.0001) and then reached a plateau (R = 2.541, P=0.3567). Male P<0.05, low BW P<0.05, and low GA P<0.05 were associated with thicker CCT at the early stage of PMA. The premature infants who had thick CCT at 40 w would have thick CCT at 52 w and 64 w accordingly. Conclusions. The CCT values of premature infants decreased over time and plateaued at 52 w PMA. Gender, BW, and GA were considered as the influential factors of CCT at the early stage of PMA. Moreover, CCT at 40 w could forecast its development trend at 52 w or 64 w after birth.

2019 ◽  
Vol 16 (3) ◽  
pp. 144-152
Author(s):  
Tanie Natung ◽  
Prasanta Kumar Goswami ◽  
Avonuo Keditsu ◽  
Wakaru Shullai

Purpose: To compare the intraocular pressure (IOP) and central corneal thickness (CCT) of non-glaucomatous North-East (NE) Indian tribals and general Indians.  Materials and methods: In a prospective, cross-sectional study, the IOP and CCT of non-glaucomatous NE Indian tribals (n = 50) and non-glaucomatous general Indians (n = 50) were compared. Glaucoma was ruled out by history, detailed ocular examinations, and investigations. Results: There was very good correlation between the CCT and IOP values of right and left eyes (p = 0.940 and 0.847, respectively). The difference in the IOP values in the two groups was not statistically significant (p = 0.312 for Oculus Dexter [OD], p = 0.400 for Oculus Sinister [OS]). Similarly, the difference in the CCT values in the two groups was not statistically significant (p = 0.736 for OD and 0.613 for OS). The mean CCT and IOP OD for the whole population was 530.50 ± 35.42 μm and 13.80 ± 2.760 mmHg, respectively. By linear regression analysis, the IOP OD of the whole population had good correlation with CCT OD of the whole population (adjusted r2 = 0.084, p = 0.002), but not with age (adjusted r2=0.000, p=0.314) and sex (adjusted r2 = 0.010, p = 0.163). Similarly, CCT OD for the whole population did not have good correlation with age (adjusted r2 = -0.009, p = 0.762) and sex (adjusted r2 = -0.007, p = 0.603). Conclusions: In this study of individuals with normal corneas and without glaucoma, no racial variation was found in the CCT and IOP values of the two groups. The IOP OD of whole population had good correlation with CCT, but not with age and sex. There was good correlation between OD and OS values of IOP and CCT.


2016 ◽  
Vol 15 (2) ◽  
Author(s):  
Satheesh Solomon T Selvin ◽  
Chris Elsa Samson Jacob ◽  
Thomas Kuriakose

Purpose: Goldmann applanation tonometry (GAT) is considered the gold standard for Intraocular Pressure (IOP) measurement. It has the disadvantages of being a contact device, need for a slit-lamp, non-portability and need of a skilled examiner. Many hospitals are using a Non Contact Tonometry (NCT) as a screening device to save clinician time, however the usefulness is not proved in terms of reliability. This study was aimed to determine the usefulness of the Air-puff tonometer (TONOREF NIDEK II, NIDEK CO., LTD., JAPAN) over a GAT in a tertiary care center. Design: Cross-sectional Study Methods: This was a cross-sectional, non interventional observational study conducted on 224 eyes (right eye) from 224 patients. All patients underwent the IOP measurement with both methods and a central corneal thickness (CCT) measured. The data was analyzed using SPSS 20.0 software. Results: The mean age of the patients was 40.3±11.29 years. There was a statistically significant difference (p<0.001) between the mean NCT and GAT readings which persisted even after correction for central corneal thickness. The correlation between NCT and GAT using Pearson’s correlation coefficient was strong irrespective of the corrections for their corneal thickness (r = 0.751 and 0.718 for uncorrected and corrected values respectively). The correlation of the individual clinicians for the readings varied from moderate to strong. The ROC curve showed the best sensitivity and specificity to occur at around 13 to 14 mmHg. Conclusion: NCT seems to overestimate the IOP at low ranges as compared to the GAT and underestimate at higher ranges. The crossover of the values is seen between 12 to 13 mmHg.  The clinician should do an individualized analysis of his/her GAT measurements to the readings of the NCT machine at the clinic to obtain clinician specific nomogram. 


2020 ◽  
Author(s):  
GRACIA CASTRO-LUNA ◽  
ANTONIO PÉREZ-RUEDA

Abstract Background: The diagnosis of keratoconus in the early stages of the disease is necessary to initiate an early treatment of keratoconus. Furthermore, to avoid possible refractive surgery that could produce ectasias. This study aims to describe the topographic, pachymetric and aberrometry characteristics in patients with keratoconus, subclinical keratoconus and normal corneas. Additionally to propose a diagnostic model of subclinical keratoconus based in binary logistic regression models Methods: The design was a cross-sectional study. It included 205 eyes from 205 patients distributed in 82 normal corneas, 40 early-stage keratoconus and 83 established keratoconus. The rotary Scheimpflug camera (Pentacam® type) analyzed the topographic, pachymetric and aberrometry variables. It performed a descriptive and bivariate analysis of the recorded data. A diagnostic and predictive model of early-stage keratoconus was calculated with the statistically significant variables Results: Statistically significant differences were observed when comparing normal corneas with early-stage keratoconus/ in variables of the vertical asymmetry to 90º and the central corneal thickness. The binary logistic regression model included the minimal corneal thickness, the anterior coma to 90º and posterior coma to 90º. The model properly diagnosed 92% of cases with a sensitivity of 97.59%, specificity 98.78%, accuracy 98.18% and precision 98.78%Conclusions: The differential diagnosis between normal cases and subclinical keratoconus depends on the mínimum corneal thickness, the anterior coma to 90º and the posterior coma to 90º.


2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Muhammad Arslan Ashraf ◽  
Muhammad Suhail Sarwar ◽  
Muhammad Awais Afzal ◽  
Imran Khalid ◽  
Sehrish Shahid

Purpose:  To compare between non-contact and contact biometry for measurements of central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and axial length (AL). Study Design: Descriptive Cross Sectional Study. Place and Duration of Study:  Mayo Hospital, Lahore from June 2018 to December 2018. Material and Methods:  Eighty-four subjects, (168 non-pathological eyes) visiting the eye outpatients department were recruited by non-probability convenience sampling. Patients with high refractive errors and suffering from any ocular pathology were excluded from the study. CCT, ACD, LT and AL were measured with non-contact Biometer (HAAG Streit) followed by Contact Biometer (Ultrasound) after taking consent from the patient. Data was entered and analyzed by using SPSS-21 and Medcalc software. Normality of quantitative data was checked with Shapiro Wilk test. Independent sample t test was used for parametric variable and Mann Whitney-U test was used for non-parametric data. For the agreement between two techniques Cohen’s Kappa test used and Bland-Altman plot was drawn for graphical presentation. P-value equal or less than 0.05 was taken as significant. Results:  Mean age of 84 subject (female: 45.24% and male: 54.76%) was 53.05 ± 13.56 years. The AL was significantly longer for the non-contact measurement with the difference of 0.53 ± 0.32 mm (p < 0.001). Contact pachymetry was significantly higher with the difference of 8.67 ± 20.83 µm (p = 0.046). ACD was significantly deeper for non-contact measurements with the difference of 0.51 ± 0.32 mm (p < 0.001). Contact ultrasound A-scan measured LT significantly thicker with the difference of 0.59 ± 0.56 mm (p < 0.001). Conclusion:  There is significant difference of axial ocular measurements (CCT, ACD, LT and AL) between contact (ultrasound A-scan) and non-contact (HAAG Streit) biometry (p < 0.05).


2020 ◽  
Author(s):  
Amr A. Gab-Alla

Abstract Background: To generate reference values of the central corneal thickness (CCT) with different refractive errors for the adult Egyptian population. Methods: A retrospective, observational, and cross-sectional study of 2200 eyes in 1166 subjects scheduled for LASIK, who came to private refractive eye center, Ismailia, Egypt. The study period was from January 2018 to January 2020. The subjects were divided into a broad range of myopia with spherical equivalent (SE) <-0.5D and hyperopia SE> +0.5D. Then, the myopic eyes divided into low (SE>-3.0D), moderate (SE-3.0D to >-6.0D), and high (SE<-6.0D). Similarly, the hyperopic eyes were divided into low (SE<+3.0 D) and moderate (SE+3.0D to <+6.0D) and high >+6.0D. The refractive error was measured by an auto-refractometer (Topcon, Tokyo Optical Co., Ltd., Japan), and CCT was measured using Sirius (CSO, Florence, Italy). Results: The data of 1100 myopic eyes in 556 subjects (30.5% males and 69.5% females) and 1100 hyperopic eyes in 610 subjects (33.6% males and 66.4% females). The mean+SD of CCT for the total myopic subjects was 531.98+32.92μm, range (406 to 636μm). The mean+SD of SE was -4.1±2.5D, range (-0.5 to -12.0D). The mean+SD of CCT for the total hyperopic subjects was 529±38.8μm, range (448 to 619 μm). The mean+SD of SE was +3.65+1.97D, range (+0.5 to +8.5D).Conclusion: In this study, the mean of CCT of the Egyptian population was 531.9 μm for myopic and 529μm for hyperopic subjects respectively. The myopic and hyperopic subjects show a reduction in CCT with age. Females have a thinner cornea than males, 23.6% of the myopic eyes, and 16.5% of the hyperopic eyes have CCT less than 500μm.


1970 ◽  
Vol 1 (1) ◽  
pp. 7-10 ◽  
Author(s):  
ST Godar ◽  
KR Kaini ◽  
JB Khattri

Background: Intra Ocular Pressure (IOP) is an important parameter for the detection and monitoring of glaucoma. Central corneal thickness (CCT) can influence the IOP estimated with Goldmann tonometry. A thick cornea overestimates the IOP and thin underestimates it. So, decreased CCT may lead to underdiagnosis and undertreatment of glaucoma and increased CCT may lead to overdiagnosis and overtreatment of glaucoma. The aim of the study is to identify the factors affecting the CCT in Nepalese population. Methods: A hospital based cross-sectional study which enrolled 152 subjects from period of January 2009 to May 2010. All subjects underwent ophthalmological examinations. CCT was measured with ultrasonic pachymeter and intraocular pressure was measured with Goldmann applanation tonometer. Results: The mean±SD CCT of right and left eye was 538±32 and 540±30μm respectively. CCT decreased with increasing age. Age and intra ocular pressure was significantly correlated with CCT. There was no significant correlation of gender and ethnicity with CCT. Conclusion: CCT decreased with increasing age. CCT was significantly correlated with age and intra ocular pressure but not with gender and ethnicity. Keywords: Nepalese; central corneal thickness; ultrasound pachymeter DOI: http://dx.doi.org/10.3126/njms.v1i1.5788   Nepal Journal of Medical Sciences. 2012; 1(1): 7-10.


2006 ◽  
Vol 77 (3) ◽  
pp. 134-140 ◽  
Author(s):  
Michael Sullivan-Mee ◽  
Kathy D. Halverson ◽  
Mollie C. Saxon ◽  
Glenn B. Saxon ◽  
Clifford Qualls

2020 ◽  
Author(s):  
GRACIA CASTRO-LUNA ◽  
ANTONIO PÉREZ-RUEDA

Abstract Background To describe the topographic, pachymetric and aberrometry characteristics in patients with keratoconus, subclinical keratoconus/forme fruste and normal corneas. Calculate a diagnostic model of subclinical keratoconus/forme fruste. Methods The design was a cross-sectional study. It included 205 eyes from 188 patients distributed in 82 normal corneas, 40 subclinical keratoconus/forme fruste and 83 established keratoconus The topographic, pachymetric and aberrometry variables obtained by rotary Scheimpflug camera (Pentacam® type) were analyzed. A descriptive and bivariate analysis of the recorded data was performed. A diagnostic model of subclinical keratoconus/forme fruste was calculated. Results Statistically significant differences were obtained when comparing normal corneas with subclinical keratoconus/forme fruste in variables of vertical asymmetry and corneal thickness.The regression model was calculated with the minimum corneal thickness and the anterior coma to 90º and posterior coma to 90º. Conclusions The diagnosis of subclinical keratoconus/forme fruste depends on the central corneal thickness, and two aberrometric topographic parameters the anterior coma to 90º and posterior coma to 90º.


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