scholarly journals Morphometric evaluation and measurements of primary pterygium by anterior segment optical coherence tomography and its relation with astigmatism

2021 ◽  
Vol 13 ◽  
pp. 251584142110201
Author(s):  
Anuradha Raj ◽  
Renu Dhasmana ◽  
Harsh Bahadur
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Cross Sectional Study ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Horizontal Length ◽  
The Mean ◽  
The Relationship ◽  
Primary Pterygium

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.

scholarly journals Evaluation of the Lower Punctum Parameters and Morphology Using Spectral Domain Anterior Segment Optical Coherence Tomography

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Riham S. H. M. Allam ◽  
Rania A. Ahmed
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Normal Subjects ◽  
Cross Sectional Study ◽  
Spectral Domain ◽  
Outer Diameter ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Air Bubble ◽  
Inner Diameter

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.

scholarly journals Correlation between Central Corneal Thickness and Degree of Myopia among Malaysian Patients Undergoing Laser Keratorefractive Surgery

2020 ◽  
pp. 52-58
Author(s):  
Sagili Chandrasekhara Reddy ◽  
Mohd Mansor Shariff ◽  
Aina Malindri Dasrilsyah
Keyword(s):  
Optical Coherence Tomography ◽  
Refractive Surgery ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Military Hospital ◽  
Moderate Degree ◽  
Optical Coherence ◽  
Corneal Refractive Surgery ◽  
The Mean

Purpose: To determine the central corneal thickness in myopic adult patients scheduled for laser corneal refractive surgery and to explore its correlation with degree of refractive error. Materials and Methods: The case records of 130 myopic patients who underwent laser corneal refractive surgery in a military hospital over a period of two years were reviewed to determine the central corneal thickness. All patients had 6/6 vision with best correction, and did not have any other anterior segment or fundus diseases in both eyes. The central corneal thickness was measured with Visante Carl Zeiss anterior segment optical coherence tomography instrument.                                                                                                                        Results: Out of 130 patients, males were more (73, 56.2%); mean age of patients was 33.8 years (range 18-60 years) and majority were Malays (110, 84.6%).  The spherical power of myopia ranged from – 0.5 to – 10.00 D, and the cylindrical power ranged from – 0.25 to – 3.25 D. The mean central corneal thickness of both eyes was 528.2 µm (range 331- 615 µm); in the mild degree of myopia (- 0.50 to - 2.00 D) 527.9 µm, moderate degree (- 2.25 to -5.00 D) 529.4 µm, and high degree (-5.25 to -11.00 D) 523.9 µm. Conclusion: The anterior segment optical coherence tomography provides noncontact, rapid, pachymetry mapping of the corneal thickness. In Malaysian patients, the mean central corneal thickness of both eyes in myopia was 528.1 µm (range 331- 615 µm). There was no correlation between the mean central corneal thickness and degree of myopia, different genders, age groups, ethnic groups and two eyes.

Anterior chamber particles are associated with reduction of intraocular pressure after selective laser trabeculoplasty

2020 ◽  
pp. bjophthalmol-2019-315445
Author(s):  
Alexei N Kulikov ◽  
Dmitrii S Maltsev ◽  
Alina A Kazak ◽  
Maria A Burnasheva
Keyword(s):  
Optical Coherence Tomography ◽  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Open Angle Glaucoma ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Selective Laser Trabeculoplasty ◽  
Cross Sectional ◽  
Laser Trabeculoplasty ◽  
The Mean

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.

scholarly journals Anterior Segment Optical Coherence Tomography in the Early Management of Microbial Keratitis: A Cross-Sectional Study

2020 ◽  
Vol 33 (5) ◽  
pp. 318 ◽  
Author(s):  
Mariana Almeida Oliveira ◽  
Andreia Rosa ◽  
Mário Soares ◽  
João Gil ◽  
Esmeralda Costa ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Parasitic Infection ◽  
Anterior Segment ◽  
Cross Sectional Study ◽  
Therapeutic Trial ◽  
Optical Coherence ◽  
Infectious Keratitis ◽  
Sectional Study ◽  
Cross Sectional ◽  
Early Management

Introduction: Infectious keratitis is an important cause of visual loss. The purpose of this study was to investigate anterior segment optical coherence tomography patterns in infectious keratitis and evaluate the role of this tool in the early management of this disorder.Material and Methods: In this cross-sectional study, we included patients with proven infectious keratitis, either by culture or therapeutic trial. Subjects underwent baseline anterior segment optical coherence tomography (Spectralis® anterior segment module, Heidelberg Engineering, Germany) performed by the same operator. We used anterior segment optical coherence tomography vertical and horizontal raster default scans with 6.0 mm scan lines.Results: Twenty-five patients (14 men and 11 women) were included. The most common risk factors identified were ocular trauma (11 cases) and contact lens wear (7 cases). Fifteen patients presented bacterial infection; three, fungal infection; two parasitic infection; and five cases presented a negative microbiological culture. Anterior segment optical coherence tomography depicted nine distinct morphological patterns.Discussion: Anterior segment optical coherence tomography allows the depth of corneal involvement to be assessed. When the only patterns identified were hyperreflective stromal lesion and stromal edema, the visual outcome was better. Cystic spaces were present in severe bacterial keratitis.Conclusion: Anterior segment optical coherence tomography can complement biomicroscopy, allowing for a better characterization of corneal involvement at presentation that can help in staging and providing useful prognostic information.

Accuracy of the indices of MS-39 anterior segment optical coherence tomography in the diagnosis of keratoconic corneas

2021 ◽  
pp. 112067212110637
Author(s):  
Rania S Elkitkat ◽  
Yasser Rifay ◽  
Hesham M Gharieb ◽  
Hossam Eldin A Ziada
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Front Surface ◽  
Receiver Operating Curve ◽  
P Value ◽  
Optical Coherence ◽  
Corneal Surface ◽  
Cross Sectional ◽  
The Mean ◽  
Group 2

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.

Quantification of Trabecular-Iris Contact and its Prevalence by Optical Coherence Tomography in a Healthy Caucasian Population

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 ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Refractive Error ◽  
Axial Length ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Fourier Domain ◽  
Optical Coherence ◽  
Cross Sectional

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.

scholarly journals Corneal Analysis with Swept Source Optical Coherence Tomography in Patients with Coexisting Cataract and Fuchs Endothelial Corneal Dystrophy

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 223
Author(s):  
Anna Nowińska ◽  
Edyta Chlasta-Twardzik ◽  
Michał Dembski ◽  
Klaudia Ulfik-Dembska ◽  
Edward Wylęgała
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Preoperative Assessment ◽  
Corneal Dystrophy ◽  
Cross Sectional Study ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Significant Area ◽  
Characteristic Features

This study focused on defining the characteristic features of keratometry and pachymetry elevation maps based on swept source optical coherence tomography (SS OCT) in Fuchs endothelial corneal dystrophy (FECD) eyes with a coexisting cataract. 70 eyes of 35 patients diagnosed with FECD and a coexisting cataract and 70 control eyes were included in this prospective, controlled, observational, cross-sectional study. Features characteristic of intermediately affected eyes included an increased corneal thinnest thickness (CTT) (p = 0.01), 3 and 6 mm asymmetry (p < 0.0001), higher order Fourier indices (p < 0.05 and p ≤ 0.0001, respectively), chord µ, and a posterior Ectasia Screening Index (pESI) (p < 0.01). The lack of agreement between the anterior and posterior elevation map and a significant area of negative values in the posterior map were detected. In advanced FECD eyes, our study additionally revealed decreased posterior keratometry steep (Ks), keratometry flat (Kf), keratometry average (AvgK), eccentricity (Ecc), an increased corneal apex thickness (CAT), and decreased 3 and 6 mm posterior spherical indices (p < 0.0001 for all of the above). Characteristic features of subclinical FECD, independent of the corneal thickness, can be detected by SS OCT and should be considered during the preoperative assessment of patients with a coexisting cataract.

Repeatability and comparability of peripapillary vessel density measurements of high-density and non-high-density optical coherence tomography angiography scans in normal and glaucoma eyes

2018 ◽  
Vol 103 (7) ◽  
pp. 949-954 ◽  
Author(s):  
Jayasree P Venugopal ◽  
Harsha Laxmana Rao ◽  
Robert N Weinreb ◽  
Srilakshmi Dasari ◽  
Mohammed Riyazuddin ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Cross Sectional Study ◽  
High Density ◽  
Vessel Density ◽  
Optical Coherence ◽  
Sectional Study ◽  
Limits Of Agreement ◽  
Cross Sectional ◽  
The Mean

AimsTo compare the peripapillary vessel density (VD) measurements of high-density (HD) and non-HD optical coherence tomography angiography (OCTA) scans in normal and glaucoma eyes, and to evaluate the intrasession repeatability of VD measurements of HD scans.MethodsIn a cross-sectional study, 46 normal (33 subjects) and 89 glaucoma (64 patients) eyes underwent 3 HD and 1 non-HD optic nerve head OCTA scans in the same session. Agreement in VD measurements between HD and non-HD scans was assessed using Bland and Altman analysis. Repeatability of the VD measurements of HD scans was assessed using within-subject coefficient of repeatability (CRw) and variation (CVw).ResultsThe mean difference in the VDs ranged between 0.7% (temporal sector VD) and 2.0% (inferonasal sector VD), with HD scans showing significantly greater VD values than non-HD scans. The 95% limits of agreement (LoA) in glaucoma eyes ranged between −2.0% and 5.0% for whole enface VD and between −4.8% and 9.6% for superotemporal VD. CRw (%) and CVw (%) of VD measurements of HD scans ranged from 3.0 to 4.9 and from 2.0 to 3.1 in normal eyes. The same ranged from 3.2 to 6.7 and from 2.6 to 4.8, respectively, in glaucoma eyes.ConclusionsVD of HD scans was higher than that of non-HD scans. The wide 95% LoA indicates that the VD measurements of HD and non-HD scans cannot be used interchangeably. Test–retest repeatability of VDs on HD scans was as high as 6%. These results should be considered while using OCTA for longitudinal evaluation of glaucoma.

scholarly journals Role of anterior segment optical coherence tomography in the evaluation of microbial keratitis

2021 ◽  
Vol 7 (3) ◽  
pp. 548-553
Author(s):  
Isha Chaturvedi ◽  
Kamaljeet Singh ◽  
Jagriti Rana ◽  
Kshama Dwivedi ◽  
Reena Sachan
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Morphological Characteristics ◽  
Objective Evaluation ◽  
Response To Treatment ◽  
Optical Coherence ◽  
Microbial Keratitis ◽  
The Mean

Anterior segment optical coherence tomography (AS-OCT) is a newer technology that provides two-dimensional images of corneal infiltration. This study was undertaken to assess whether AS-OCT can aid objective evaluation and response to treatment in resolving microbial keratitis. This prospective study was performed on 17 patients of who underwent slit lamp and AS-OCT examination at presentation and follow up on days 3, 7, 14, 28 and 6 weeks. A standardized scanning protocol was used to measure the corneal thickness (CT) and infiltrate thickness (IT) using the caliper tool of a commercially available AS-OCT device. The mean CT in the infiltrated area and mean IT, both were thickest at presentation (710.88 um and 288.76 um respectively). The mean CT decreased to 665.12 µm, 650.24 µm, 584.35 µm, 549 µm, 507.47 µm on days 3, 7, 14, 28 and 6 weeks respectively. Similarly, the mean IT decreased to 287.24 µm, 244.41 µm, 197 µm, 174.59 µm and 154.82 µm. Paired t- test was used to calculate the statistical change in CT and IT, which was significant (p&#60;0.0001) at 6 weeks, at the rate of 0.67% and 1.01% per day. AS-OCT can show morphological characteristics of microbial keratitis and give quantitative assessment at every follow up.

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