scholarly journals Evaluation of anterior chamber volume using Pentacam and anterior segment optical coherence tomography among normal subjects

2018 ◽  
Vol 16 (2) ◽  
pp. 86-94
Author(s):  
Vijaya Anandan ◽  
Rekha Srinivasan ◽  
Rashima Asokan ◽  
Ronnie George

Aim: To compare the anterior chamber volume measurements obtained with Pentacam and derived from anterior segment optical coherence tomography. Design: Cross-sectional study. Methods: We included normal subjects who underwent a comprehensive eye examination including refraction, keratometry, Goldmann applanation tonometry, gonioscopy, anterior segment optical coherence tomography (AS-OCT) (Carl Zeiss Meditec Inc.; Dublin, CA, USA) and Pentacam (Oculus Inc.; Lynnwood, WA, USA). Fifty scans were selected for Pentacam and 12 images were selected for calculation of anterior chamber volume. Only the right eye was considered for analysis. Results: One-hundred and nineteen eyes of 119 subjects were included for analysis. The mean age of the subjects was 42.58 ± 13.15 years, of which 74 were female and 45 were male. The mean anterior chamber volume measured using AS-OCT was 119.17 ± 26.56 mm3 and with Pentacam was 131.29 ± 34.26 mm3. The comparison of means between the two modalities was statistically significant (t = -8.857, Mean Difference (MD) = 12.11, 95% CI: (4.29, 19.95), p = 0.003). Bland-Altman plot showed poor agreement between the chamber volume measurements obtained by Pentacam and AS-OCT with MD of 12.1 mm3 (95 % CI: 41.4 to -17.1) and intra-class correlation between the two instruments was 0.94 (95% CI: 0.91, 0.96) (p < 0.0001). Conclusion: The anterior chamber volume can be measured using Pentacam as well as AS-OCT since these measurements were reliable. However, these measurements were not interchangeable due to poor levels of agreement.

2020 ◽  
pp. bjophthalmol-2019-315445
Author(s):  
Alexei N Kulikov ◽  
Dmitrii S Maltsev ◽  
Alina A Kazak ◽  
Maria A Burnasheva

PurposeTo study the correlation between intraocular pressure (IOP) reduction and the number of hyper-reflective particles appearing in the anterior chamber following selective laser trabeculoplasty (SLT).Material and methodsIn this prospective interventional study, we included primary open-angle glaucoma patients. All participants received a standardised SLT session, which consisted of 100 pulses of 0.9 mJ over 360°. Anterior segment optical coherence tomography (4×4 mm volume scan, 101 horizontal cross-sectional scans) and applanation tonometry were performed before SLT and 15 min, 1 day, 1 week, 1 month and 3 months after. Particles were counted on cross-sectional scans using a standardised algorithm.ResultsIn this study, we included 25 patients (25 eyes), 14 males and 11 females, with a mean age of 68.9±10.5 and baseline IOP of 21.4±4.5 mm Hg. IOP at month 1 and month 3 after SLT was 18.0±4.0 and 17.4±3.3 mm Hg, respectively. The mean number of anterior chamber particles before and 15 min after SLT was 0.62±0.2 and 7.1±2.0 particles/mm2, respectively (p=0.036). There was a statistically significant correlation between the mean number of anterior chamber particles 15 min after SLT and IOP reduction at 1 month (r=0.62, p=0.03) and 3 months (r=0.71, p=0.01).ConclusionThe number of the anterior chamber particles graded using anterior segment optical coherence tomography after the procedure correlates with the IOP-lowering effect of SLT.


Author(s):  
Alireza Khodabande ◽  
Massood Mohammadi ◽  
Hamid Riazi-Esfahani ◽  
Shahab Karami ◽  
Massood Mirghorbani ◽  
...  

Abstract Background To evaluate changes in anterior segment morphology on anterior segment optical coherence tomography (AS-OCT) following pars plana vitrectomy (PPV) without tamponade. Methods Patients who underwent PPV without tamponade for epiretinal membrane were evaluated. Eligible patients underwent intraocular pressure (IOP) measurement and AS-OCT preoperatively as well as 1 month and 6 months post-operatively. Anterior chamber width (ACW), anterior chamber depth (ACD), trabecular iris angle (TIA), angle opening distance at 500 and 750 µm (AOD), and trabecular iris space area at 500 and 750 µm (TISA) at four quadrants were recorded and analyzed. Additionally, the mean values of TIA (MTIA), AOD (MAOD), and TISA (MTISA) for each eye (mean of four quadrants) were analyzed. Results 23 patients completed the study. The mean age of participants was 56.4 ± 3.6 years of age and 13/23 (56%) were female. Mean IOP of patients was 18.1 ± 1.1, 18.3 ± 1.1, and 18.1 ± 1.2 preoperatively,1 month post-operatively, and 6 months post-operatively, respectively. (p = 0.83). No difference was detected post-operatively in measurements of ACW, ACD, MTIA, MAOD500, MAOD750, MTISA500, and MTISA750. Conclusion Pars plana vitrectomy without tamponade was not associated with changes in anterior chamber morphology.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Riham S. H. M. Allam ◽  
Rania A. Ahmed

Purpose. To study features of the lower punctum in normal subjects using spectral domain anterior segment optical coherence tomography (SD AS-OCT).Methods. Observational cross-sectional study that included 147 punctae (76 subjects). Punctae were evaluated clinically for appearance, position, and size. AS-OCT was used to evaluate the punctal shape, contents, and junction with the vertical canaliculus. Inner and outer diameters as well as depth were measured.Results. 24 males and 52 females (mean age44±14.35 y) were included. Lower punctum was perceived by OCT to be an area with an outer diameter (mean412.16±163 μm), inner diameter (mean233.67±138.73 μm), and depth (mean251.7±126.58 μm). The OCT measured outer punctum diameter was significantly less than that measured clinically (P: 0.000). Seven major shapes were identified. The junction with the vertical canaliculus was detectable in 44%. Fluid was detected in 34%, one of which had an air bubble; however, 63% of punctae showed no contents and 4% had debris.Conclusions. AS-OCT can be a useful tool in understanding the anatomy of the punctum and distal lacrimal system as well as tear drainage physiology. Measuring the punctum size may play a role in plugs fitting.


2021 ◽  
pp. 112067212110637
Author(s):  
Rania S Elkitkat ◽  
Yasser Rifay ◽  
Hesham M Gharieb ◽  
Hossam Eldin A Ziada

Purpose To determine the normative and the cut-off values of various indices available in the MS 39 Anterior Segment Optical Coherence Tomography (MS-39 AS-OCT) for keratoconus (KC) diagnosis, and to detect the accuracy of the variable available parameters. Methods This cross sectional observational study was conducted at Dr Rifay Ophthalmology Center, Rabat, Morocco, on 172 eyes with KC (group 1) and 248 eyes of healthy controls (group 2). Participants were screened using MS-39 AS-OCT (CSO, Firenze, Italy). The investigated indices included: keratometric indices, pachymetric indices, elevation indices, Keratoconus Summary Indices (KSI), aberration indices, and epithelial mapping evaluation. Results Most of the studied indices were significantly different between both groups (P value <0.001). Twenty two indices had Area Under the Receiver Operating Curve (AUROC) values >0.950, eight of which were from the KSI. The indices with the highest AUROC values were: Root Mean Square (RMS) for the front corneal surface at 6 mm circle (AUROC = 0.996, and best cut-off >1.69 with sensitivity of 97.67% and specificity of 97.98%) and RMS per unit of area for the front surface at 6 mm circle (AUROC = 0.996, and best cut-off >0.06 with sensitivity of 97.67% and specificity of 97.98%). Epithelial thickness-derived metrics were not among the parameters with the highest accuracy. Conclusions This study presented the mean and the cut-off values for a plethora of parameters available in the MS-39 AS-OCT. The results of this study show that MS-39 AS-OCT is a valuable equipment for diagnosing keratoconic corneas, with a high accuracy detected for many parameters.


2016 ◽  
Vol 27 (4) ◽  
pp. 417-422 ◽  
Author(s):  
José Ignacio Fernández-Vigo ◽  
Lucía De-Pablo-Gómez-De-Liaño ◽  
Cristina Fernández-Vigo ◽  
Inés Sánchez-Guillén ◽  
Enrique Santos-Bueso ◽  
...  

Purpose To determine the prevalence of trabecular-iris contact (TIC) and quantify this contact in healthy Caucasian individuals using Fourier-domain optical coherence tomography (FD-OCT). Methods For this cross-sectional study, 2,012 eyes of 1,006 healthy subjects were recruited among individuals undergoing a routine ophthalmologic checkup. In each participant, age, sex, intraocular pressure, and spherical refractive error were first recorded along with anterior chamber depth and volume, central corneal thickness measured with the Pentacam, and axial length with the IOLMaster. Anterior chamber angle variables and the presence of TIC in the horizontal quadrants were determined by anterior segment FD-OCT (RTVue 100®). When TIC was observed, TIC length (TICL) and its percentage in relation to the length of the trabecular meshwork (TICL percentage) were also measured. Results Trabecular-iris contact in the horizontal quadrants was observed in 34 eyes of 25 patients, representing 1.6% of the total number of eyes examined. In this subgroup of individuals, mean age was 55.8 years, 84% were women, and spherical refractive error ranged from -0.25 to 8.25 D. Eyes with TIC showed an angle width of less than 23.2 degrees and axial length shorter than 23.7 mm. Mean TICL was 239 ± 79 μm (103-495 μm) and mean TICL percentage was 46.9% ± 13.9% (17.2%-76.3%). Conclusions The prevalence of TIC was low in this population. Fourier-domain optical coherence tomography emerged as useful to assess its prevalence and quantify the extent of TIC.


2013 ◽  
Vol 38 (5) ◽  
pp. 531-536 ◽  
Author(s):  
Reina Fukuda ◽  
Tomohiko Usui ◽  
Takashi Miyai ◽  
Yosai Mori ◽  
Kazunori Miyata ◽  
...  

2021 ◽  
Vol 13 ◽  
pp. 251584142110201
Author(s):  
Anuradha Raj ◽  
Renu Dhasmana ◽  
Harsh Bahadur

Purpose: To evaluate the relationship between measurements and various morphometric parameters of primary pterygium on anterior segment optical coherence tomography(AS-OCT) and refractive and keratometric astigmatism. Methods: In this cross-sectional study, patients with primary pterygium were included. The AS-OCT parameters of pterygium consisting of epithelial thickness near apex(µm), apical or head thickness(µm), its thickness at limbus(µm), horizontal length of pterygium(mm), central corneal thickness (µm) and maximum pterygium thickness(mm) were evaluated. Results: Sixty three patients comprising of 63 eyes with a primary pterygium were studied. The mean keratometric and refractive astigmatism were 1.69 ± 3.15 Diopter(D) and0.5 ± 1.4D, respectively. There was a significant association between pterygium grade and stocker’s line with keratometric astigmatism ( p = 0.02, 0.00) respectively. Vertical and horizontal length on slit lamp and horizontal length on AS-OCT showed significant association with keratometric astigmatism ( p = 0.05, 0.00,0.00), respectively. Limbal thickness on AS-OCT showed significant positive correlation with refractive astigmatism ( r = 0.29, p = 0.02). Conclusion: The pterygium grade influences the keratometric astigmatism. Increased limbal thickness of pterygium on AS-OCT leads to more refractive astigmatism.


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