Genetic Covariance Between Central Corneal Thickness and Anterior Chamber Volume: A Hungarian Twin Study

2014 ◽  
Vol 17 (5) ◽  
pp. 397-404 ◽  
Author(s):  
Georgina Zsofia Toth ◽  
Adel Racz ◽  
Adam Domonkos Tarnoki ◽  
David Laszlo Tarnoki ◽  
Zita Szekelyhidi ◽  
...  

Background: Few, and inconsistent, studies have showed high heritability of some parameters of the anterior segment of the eye; however, no heritability of anterior chamber volume (ACV) has been reported, and no study has been performed to investigate the correlation between the ACV and central corneal thickness (CCT). Methods: Anterior segment measurements (Pentacam, Oculus) were obtained from 220 eyes of 110 adult Hungarian twins (41 monozygotic and 14 same-sex dizygotic pairs; 80% women; age 48.6 ± 15.5 years) obtained from the Hungarian Twin Registry. Results: Age- and sex-adjusted heritability of ACV was 85% (bootstrapped 95% confidence interval; CI: 69% to 93%), and 88% for CCT (CI: 79% to 95%). Common environmental effects had no influence, and unshared environmental factors were responsible for 12% and 15% of the variance, respectively. The correlation between ACV and CCT was negative and significant (rph = −0.35, p < .05), and genetic factors accounted for the covariance significantly (0.934; CI: 0.418, 1.061) based on the bivariate Cholesky decomposition model. Conclusion: These findings support the high heritability of ACV and central corneal thickness, and a strong genetic covariance between them, which underscores the importance of identification of the specific genetic factors and the family risk-based screening of disorders related to these variables, such as open-angle and also angle closure glaucoma and corneal endothelial alterations.

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Carmen Lopez de la Fuente ◽  
Ana Sanchez-Cano ◽  
Francisco Segura ◽  
Lorena Fuentes-Broto ◽  
Isabel Pinilla

Purpose. To assess the repeatability of the Galilei dual Scheimpflug analyzer (GDSA) in anterior segment examination.Methods. Fifty-two eyes from 52 healthy volunteers were prospectively and consecutively recruited. Anatomic, axial, refractive, and instantaneous parameters were measured with GDSA to provide a complete characterization of the anterior segment. Repeatability was assessed calculating intraclass correlation coefficient (ICC), and coefficient of variation (COV).Results. Correlation among repeated measurements showed almost perfect reliability (ICC > 0.81) for all parameters except thinnest central corneal thickness (CCT) (0.78), corneal thickness average out (0.79), and posterior axial curvature average out (0.60). Repeatability was excellent (COV<10%) for all parameters except anterior chamber volume and, superior iridocorneal angle and eccentricities. In these last three parameters, repeatability limits were excessively high compared to the mean.Conclusions. GDSA in healthy young persons had an almost perfect correlation in measuring anatomic, axial, instantaneous, and refractive parameters with greater variability for peripheral terms. Repeatability of anatomical parameters like pachymetry, anterior chamber, or iridocorneal angle and eccentricity were limited. In healthy young persons, the other evaluated parameters had very good repeatability and their limits of agreement showed excellent clinical results for this device.


2016 ◽  
Vol 236 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Hussam El Chehab ◽  
Emilie Agard ◽  
Aurélie Russo ◽  
Ygal Boujnah ◽  
Corinne Dot

The objective of this study was to assess the intraocular pressure (IOP) as well as the anatomical modifications of the anterior segment following an aflibercept injection. Patients underwent an aflibercept intravitreal injection (IVI) (0.05 ml) with a 30.5-gauge needle and an antireflux system. IOP was assessed before injection (T0), immediately after (T1), and 5 min (T5), 15 min (T15), and 45 min (T45) after the IVI. Before the IVI and immediately after the T1 measurement, a PENTACAM® acquisition was used to evaluate the anterior chamber parameters (anterior chamber volume, depth and measure of the iridocorneal angle). At T0, IOP was 12.9 ± 1.3 mm Hg. IOP significantly increased after IVI (42.7 ± 3 mm Hg, p < 0.001). IOP returned to baseline at T45 (13.0 ± 1.2 mm Hg, p = 0.877). Anterior chamber volume decreased after IVI (160.6 vs. 168.3 mm3, p = 0.002). No significant changes were found for iridocorneal angle and anterior chamber depth. Aflibercept IVI causes an acute increase in IOP over a short period without iridocorneal angle closure.


2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Mi Tian ◽  
Weijun Jian ◽  
Xiaoyu Zhang ◽  
Ling Sun ◽  
Yang Shen ◽  
...  

Abstract Background This study aimed to evaluate the clinical outcomes and assess preoperative characteristics that may predict outcomes in keratoconus 1 year after accelerated transepithelial corneal cross-linking (ATE-CXL). Methods This prospective study included 93 eyes of 84 consecutive keratoconus patients with 1-year follow-up after ATE-CXL. Preoperative characteristics included corneal astigmatism, anterior chamber depth, anterior chamber volume, radius of curvature, posterior elevation, central corneal thickness (CCT), thinnest corneal thickness, steepest meridian keratometry, flattest meridian keratometry, and the maximum keratometry (Kmax). Data were obtained preoperatively and at 1, 3, 6, and 12 months postoperatively. The patient eyes were grouped into 3 subgroups according to CCT and Kmax values to observe the changes of keratoconus progression. Results All patients were successfully operated without complications at any follow-up time point. Mean changes of Kmax from baseline at 6 and 12 months were − 0.60 ± 2.21 D (P = 0.011) and − 0.36 ± 1.58 D (P = 0.030), respectively. Eyes with a thinner CCT and higher Kmax values exhibited a tendency for topographic flattening of ≥1.0 D (P = 0.003; P = 0.003). In the subgroup comparison, the Kmax values decreased significantly at 6 and 12 months after ATE-CXL in the group with CCT ≤ 450 μm (P = 0.018 and P = 0.045); the Kmax values of the group with Kmax > 65.0 D decreased significantly at 6 months postoperatively (P = 0.025). Conclusion ATE-CXL is a safe and effective treatment for keratoconus patients. Patients with thinner CCT and higher Kmax values are more likely to benefit from ATE-CXL.


2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Ercan Ozsoy ◽  
Abuzer Gunduz ◽  
Ersin Ersan Demirel ◽  
Tongabay Cumurcu

Purpose. To evaluate anterior segment’s structures by Pentacam in patients with tilted disc syndrome (TDS).Methods. Group 1 included forty-six eyes of forty-six patients who have the TDS. Group 2 including forty-six eyes of forty-six cases was the control group which was equal to the study group in age, gender, and refraction. A complete ophthalmic examination was performed in both groups. All cases were evaluated by Pentacam. The axial length (AL) of eyes was measured by ultrasound. Quantitative data obtained from these measurements were compared between two groups.Results. There was no statistically significant difference for age, gender, axial length, and spherical equivalent measurements between two groups (p=0.625,p=0.830,p=0.234, andp=0.850). There was a statistically significant difference for central corneal thickness (CCT), corneal volume (CV), anterior chamber angle (ACA), and pupil size measurements between two groups (p=0.001,p=0.0001,p=0.003, andp=0.001). Also, there was no statistically significant difference for anterior chamber depth (ACD), anterior chamber volume (ACV), and lens thickness (LT) measurements between two groups (p=0.130,p=0.910, andp=0.057).Conclusion. We determined that CCT was thinner, CV was less, and ACA was narrower in patients with TDS. There are some changes in the anterior segment of the eyes with tilted disc.


2021 ◽  
Author(s):  
Fatih Akıncı ◽  
Abdullah Arslan ◽  
Muammer Özcimen

Abstract Purpose: In this study the acute effects of 1 session of hyperbaric oxygen therapy on eye anterior segment morphology and on intraocular pressure was evaluated.Materials and methods: 30 patients taking hyperbaric oxygen therapy for different indications were included in this prospective study. Only the right eye per patient was included in the study. The refractive errors were measured with autorefractometry, intraocular pressures were measured with pneumatic tonometry; anterior segment parameters pachymetry, keratometry, anterior chamber depth and iridocorneal angle values were measured with corneal topography prior to and 24 hours after 1 session of hyperbaric oxygen therapy.Results: In this study 30 eyes from a total of 30 patients were evaluated; 19 men (% 64) and 11 women (% 36). Median age was 44.33 ±16.12 (Age range 18-80 years). Mean intraocular pressure was 13.7 ±4,16 mmHg (milimetermercuries), mean central corneal thickness was 531.9 ±28.24 μm, mean anterior chamber depth was 3.30 ±0.375 mm, mean iridocorneal angle value was 35.3± 6.61 degrees before hyperbaric oxygen therapy. The mean intraocular pressure was 12.66±4,54 mmHg, mean central corneal thickness was 529.43± 26.68 μm, mean anterior chamber depth was 3.28±0.372 mm, mean iridocorneal angle value was 34.5±6.42 degrees after HBOT. A statistically significant decrease in these values were recorded. No statistically significant changes were found in spheric equivalent and keratometry values of the patients before and after HBOT.Conclusions: After one session of HBOT a decrease in intraocular pressure, central corneal thickness, anterior chamber depth and iridocorneal angles of patients were observed; keratometry and spheric equivalent values remained unchanged. More studies are needed in order to use the effects of HBOT on anterior segment morphology and on intraocular pressure for situations like glaucoma, corneal edema etc.


2021 ◽  
Vol 37 (3) ◽  
Author(s):  
Muhammad Suhail Sarwar ◽  
Sehrish Shahid ◽  
Muhammad Arslan Ashraf ◽  
Shaista Kanwal

Purpose:  To check inter observer reproducibility of axial ocular measurements i.e. central corneal thickness (CCT), anterior chamber depth (ACD), aqueous depth (AD), lens thickness (LT), anterior segment lens (ASL), vitreous length (VL) and axial length (AL) with non-contact HAAG-STRAIT biometer. Study Design:  Comparative Reproducibility Analysis. Place and Duration of Study:  College of ophthalmology and allied vision sciences (COAVS), Mayo Hospital, Lahore. Methods:  This study included 66 healthy students (132 eyes). Data was collected through self-designed proforma by 2 operators independently. SPSS 21 was used for data analysis. Interclass correlation was applied for agreement between the two readings. Interclass coefficient (ICC) value greater than 0.7 was considered as excellent correlation. Results:  The mean CCT, AD, ACD, LT, ASL, VL, and AL were 526.47 ± 35.72 µm and 526.47 ± 36.06 µm (ICC = 0.92); 2.93 ± 0.29 mm and 2.93 ± 0.29 mm (ICC = 0.81); 3.45 ± 0.30 mm and 3.46 ± 0.30 mm (ICC = 0.79); 3.58 ± 0.28 mm and 3.56 ± 0.22 mm (ICC = 0.76); 7.03 ± 0.30 mm and 7.02 ± 0.27 mm (ICC = 0.80); 16.56 ± 0.85 mm and 16.62 ± 0.81 mm (ICC = 0.72); and 23.59 ± 0.85 mm and 23.64 ± 0.87 mm (ICC: 0.76) of observer 1 and 2, respectively. Conclusion:  Non-contact Biometer (HAAG-STRAIT) has high inter-observer reproducibility with strong interclass coefficient of greater than 0.72. Key Words:  Biometry, Axial Length, Central Corneal Thickness, Anterior Chamber Depth.


2016 ◽  
Vol 8 (12) ◽  
pp. 133 ◽  
Author(s):  
Neda Nakhjavanpour ◽  
Abolfazl Payandeh ◽  
Majid Rajabi ◽  
Vahid Shoja

<p>Anterior segment eye parameters are essential factors in diagnosis, screening and management of abnormal ocular conditions. Based on the previous studies, they might differ from one race or population to another. Sistan-and-Baluchestan province, the southeast of Iran, has special weather conditions and race, plus lack of research on these diagnostic factors. Hence, the objective of the present study was to assess anterior segment parameters using pentacam in this area. 800 eyes of subjects which had been referred to the Al-Zahra eye hospital of Zahedan, the capital city of the province, for corneal refractive surgery from October 2014 to March 2015 participated in this research. 95% confidence limits for mean of central corneal thickness, anterior chamber depth and volume were (536.02, 541.20), (3.13, 3.18) and (187.63, 192.58) respectively. Multiple linear regression models showed a lower mean central corneal thickness, and maximum/minimum of keratometry, for males than females, adjusting for age and spherical equivalent. Inversely, anterior chamber depth, and volume were more in males. In order to diagnosis and treating ocular diseases which have effect on retinal thickness, precisely specification of predictive factors is highly needed.</p>


2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Jinhai Huang ◽  
Weicong Lu ◽  
Giacomo Savini ◽  
Hao Chen ◽  
Chengfang Wang ◽  
...  

Purpose.To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan) and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA) for measuring central corneal thickness (CCT), anterior chamber depth (ACD), and aqueous depth (AD).Methods.Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using pairedt-tests, Bland-Altman plots, and 95% limits of agreement (LoA).Results.The mean CCT, ACD, and AD measured by AL-Scan were538.59±27.37 μm,3.70±0.30 mm, and3.16±0.30 mm, respectively. The mean values obtained by the Visante OCT were536.14±26.61 μm for CCT,3.71±0.29 mm for ACD, and3.17±0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference =2.45±6.07 μm,P<0.05). The differences in ACD and AD measurements were not statistically significant. The 95% LoA of CCT, ACD, and AD were between −9.44 and 14.35 μm, −0.15 and 0.12 mm, and −0.15 and 0.12 mm, respectively.Conclusions.Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic.


2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Wakako Ikegawa ◽  
Takashi Suzuki ◽  
Koji Namiguchi ◽  
Shiro Mizoue ◽  
Atsushi Shiraishi ◽  
...  

Purpose. To quantify changes in anterior segment (AS) parameters after laser peripheral iridotomy (LPI) using AS-optical coherence tomography (OCT) of iris bombe. Method. AS images of eight eyes were captured before and after iris bombe and more than 2 weeks after LPI (post-LPI) using AS-OCT. We compared the following AS parameters: anterior chamber depth (ACD), anterior chamber volume (ACV), iris curvature (IC), iris thickness at 500 μm from the scleral spur (IT-1) in the middle between the iris root and pupillary margin (IT-2) and 500 μm from the pupillary margin (IT-3) to the anterior chamber angle (ACA) (angle opening distance [AOD750]), and trabecular iris space area. Results. Mean IT-1 and IT-3, but not IT-2, were lower after iris bombe (IT-1, P=0.001; IT-2, P=0.081; and IT-3, P=0.001). There were no significant differences between ACD at pre-LPI and before iris bombe (P=0.096). The mean ACV and AOD750 of iris bombe increased at post-LPI (ACV, P<0.01, and AOD750, P<0.05). The mean IT-1, IT-2, and IT-3 increased at post-LPI (all, P≤0.01). IC decreased at post-LPI (P<0.001), and ACD at post-LPI did not change. Conclusions. The iris extends and becomes thinner during iris bombe. LPI during bombe decreases the IC and increases the ACV and ACA.


2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Mustafa Doğan ◽  
Mehmet Cem Sabaner ◽  
Mehmet Akif Erol

Purpose. To determine the effect of proparacaine 0.375%-sodium fluorescein 0.25% eye drop mixture and fluorescein strip on anterior segment parameters commonly used in routine ophthalmology practice. Methods. 115 healthy volunteers without any systemic or ocular disease were divided into two groups. 57 volunteers were in the proparacaine 0.375%-sodium fluorescein 0.25% eye drop mixture group, and 58 volunteers were in the fluorescein strip group. Measurements (CCT (central corneal thickness), topographic pupil diameter, AD (aqueous depth), ACV (anterior chamber volume), ICA (iridocorneal angle), LLD (limbus-limbus distance), and CV (corneal volume)) were taken before and at 1, 5, 15, and 30 minutes after application. Results. 59 (51.3%) participants were female, and 56 (48.7%) were male. The mean age of the drop application group was 26.88 ± 8.03, and the mean age of the strip application group was 26.33 ± 7.28. The mean CCT was 556 ± 32 μm before drop application and 569 ± 30 μm in the 1st minute, 560 ± 32 μm in the 5th minute, and 559 ± 31 μm in the 15th minute. The change was statistically significant (p<0.001, p=0.005, and p=0.013, resp.). Before the strip application, mean CCT was 552 ± 36 μm, while it increased to 556 ± 36 μm at the 1st minute, and this change was statistically significant (p=0.002). The mean CV before dropping was 59.29 ± 3.53 mm3 and 60.62 ± 3.53 mm3 at the 1st minute and 59.66 ± 3.70 mm3 at the 5th minute, which was statistically significant (p<0.001 and p=0.034). Mean topographic pupil diameters at the 1st, 5th, 15th, and 30th minute after application of drops and strips were not significantly changed compared to the preapplication values in the AD, ACV, ICA, and LLD measurements. Conclusions. Proparacaine 0.375%-sodium fluorescein 0.25% eye drop mixture and fluorescein strip application lead to a temporary change in CCT and CV of the anterior segment parameters. Anterior segment measurements with the Scheimpflug camera have to be done before topical fluorescein application.


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