scholarly journals The mechanism of intraocular pressure rise after keratoplasty

2021 ◽  
Vol 8 (2) ◽  
pp. 114-123
Author(s):  
Diana Wyroślak-Bednarek ◽  
Zofia Pniakowska ◽  
Piotr Jurowski
Keyword(s):  
Optical Coherence Tomography ◽  
Intraocular Pressure ◽  
Clinical Observation ◽  
Anterior Segment ◽  
Pressure Rise ◽  
Lamellar Keratoplasty ◽  
Optical Coherence ◽  
Pupillary Block ◽  
Iridocorneal Angle ◽  
Corneal Grafting

Purpose: To determine the pathomechanism of increased intraocular pressure after penetrating and lamellar keratoplasty based on clinical observation and literature data. Materials and methods: Morphometric analysis of the anterior segment of the eye using spectroscopic optical coherence tomography, gonioscopy and biomicroscopy. Results: Pre- and postoperative spectroscopic optical coherence tomography scans in patients after keratoplasty reveal deformation of the peripheral cornea, narrowing of the iridocorneal angle, presence of anterior synechiae and various types of pupillary block. Conclusions: The mechanism of elevated intraocular pressure after corneal grafting is complex and depends on pre-, intra- and postoperative factors, such as anatomy changes of the iridocorneal angle, presence of anterior synechiae, as well as anterior and posterior pupillary block. Spectroscopic optical coherence tomography plays an important role in diagnosis and further treatment management.

scholarly journals The Use of Anterior-Segment Optical-Coherence Tomography for the Assessment of the Iridocorneal Angle and Its Alterations: Update and Current Evidence

2021 ◽  
Vol 10 (2) ◽  
pp. 231
Author(s):  
Giacinto Triolo ◽  
Piero Barboni ◽  
Giacomo Savini ◽  
Francesco De Gaetano ◽  
Gaspare Monaco ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Intraocular Pressure ◽  
Clinical Relevance ◽  
Anterior Segment ◽  
Angle Closure ◽  
Current Evidence ◽  
Optical Coherence ◽  
Iridocorneal Angle ◽  
Wide Range

The introduction of anterior-segment optical-coherence tomography (AS-OCT) has led to improved assessments of the anatomy of the iridocorneal-angle and diagnoses of several mechanisms of angle closure which often result in raised intraocular pressure (IOP). Continuous advancements in AS-OCT technology and software, along with an extensive research in the field, have resulted in a wide range of possible parameters that may be used to diagnose and follow up on patients with this spectrum of diseases. However, the clinical relevance of such variables needs to be explored thoroughly. The aim of the present review is to summarize the current evidence supporting the use of AS-OCT for the diagnosis and follow-up of several iridocorneal-angle and anterior-chamber alterations, focusing on the advantages and downsides of this technology.

scholarly journals Age-Related Changes in the Rhesus Macaque Eye

2021 ◽  
Author(s):  
Kira Lin ◽  
Tu Tran ◽  
Soohyun Kim ◽  
Sangwan Park ◽  
Jiajia Chen ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Intraocular Pressure ◽  
Rhesus Macaque ◽  
Axial Length ◽  
Rhesus Macaques ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Lens Thickness ◽  
Age Related ◽  
Age Related Changes

Purpose: To assess age-related changes in the rhesus macaque eye and evaluate them to corresponding human age-related eye disease. Methods: Data from eye exams and imaging tests including intraocular pressure (IOP), lens thickness, axial length, and retinal optical coherence tomography (OCT) images were evaluated from 142 individuals and statistically analyzed for age-related changes. Quantitative autofluorescence (qAF) was measured as was the presence of macular lesions as related to age. Results: Ages of the 142 rhesus macaques ranged from 0.7 to 29 years (mean=16.4 years, stdev=7.5 years). Anterior segment measurements such as IOP, lens thickness, and axial length were acquired. Advanced retinal imaging in the form of optical coherence tomography and qAF were obtained. Quantitative assessments were made and variations by age groups were analyzed to compare with established age-related changes in human eyes. Quantitative analysis of data revealed age-related increase in intraocular pressure, ocular biometry (lens thickness and axial length), and presence of macular lesions. Age-related changes in thicknesses of retinal layers on OCT were observed and quantified. Age was correlated with increased qAF. Conclusions: The rhesus macaque has age-related ocular changes similar to humans. IOP increases with age while retinal ganglion cell layer thickness decreases. Macular lesions develop in some aged animals. Our findings support the concept that rhesus macaques may be useful for the study of important age-related diseases such as glaucoma, macular diseases, and cone disorders, and for development of therapies for these diseases.

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 Swept Source Optical Coherence Tomography Analysis of the Selected Eye’s Anterior Segment Parameters

2021 ◽  
Vol 10 (5) ◽  
pp. 1094
Author(s):  
Michał Dembski ◽  
Anna Nowińska ◽  
Klaudia Ulfik-Dembska ◽  
Edward Wylęgała
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Swept Source ◽  
Iridocorneal Angle ◽  
Glaucoma Diagnosis ◽  
Good Repeatability ◽  
Anterior Segment Parameters ◽  
Important Marker

Background: The present study determined the mean reference values of the anterior segment parameters of the selected eye using swept source optical coherence tomography (SS-OCT) in healthy Caucasian participants. Methods: A total of 166 volunteers (age 54–79 years), women (n = 92) and men (n = 74), were analyzed. One eye of each subject was randomly selected for anterior segment imaging. The anterior segment of the eye was scanned with CASIA2. The analyzed anterior segment parameters were divided into three groups, namely parameters of the cornea, lens, and angle. Results: The OCT (e.g., Ks, Kf, pKf, pKs, and central corneal thickness) and Fourier parameters of the cornea were significantly different between females and males. The iridocorneal angle was the smallest in the upper quadrant for all distance from the apex of the angle (250, 500, and 750 µm). Conclusions: Therefore, SS-OCT enables the analysis of parameters of the cornea, anterior chamber, lens, and iridocorneal angle, highlighting its clinical utility. Sex-specific differences in the analyzed parameters should be taken into account during the diagnosis of corneal diseases. The configuration of the filtration angle is an important marker during glaucoma diagnosis and drainage implant surgery. Measurements with CASIA 2is characterized by very good repeatability.

scholarly journals Anterior segment optical coherence tomography documentation of Reverse Pupillary Block -A case of Pigment Dispersion Syndrome in a 10 year Old Child

2016 ◽  
Vol 15 (1) ◽  
pp. 34-39
Author(s):  
Devendra Maheshwari ◽  
Renagappa Ramakrishnan ◽  
Neelam Pawar
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Pigment Dispersion ◽  
Optical Coherence ◽  
Laser Peripheral Iridotomy ◽  
Pupillary Block ◽  
Laser Iridotomy ◽  
Pigment Dispersion Syndrome ◽  
History Of ◽  
Peripheral Iridotomy

We report a 10-year-old boy with unusually dense, bilateral central posterior capsule pigmentation associated with the characteristic clinical features of pigment dispersion syndrome, including Krukenberg’s spindle and dense trabecular pigmentation in both eyes. There was no history of trauma , laser or intraocular surgeries . The presence of posterior or backward bowing of iris suggested a reverse pupillary block mechanism of pigment dispersion syndrome. Nd Yag laser peripheral iridotomy was performed in both eyes to relieve reverse pupillary block. Anterior segment optical coherence tomography (AS-OCT) showed reversal of iris concavity after laser iridotomy.

scholarly journals Precise geometry of the anterior chamber of the eye by means of OCT imaging.

2018 ◽  
Vol 10 (3) ◽  
pp. 67
Author(s):  
Marta Katarzyna Skrok ◽  
Damian Siedlecki ◽  
David Alonso-Caneiro
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Distortion Correction ◽  
Diagnostic Methods ◽  
Optical Distortion ◽  
Optical Coherence ◽  
Refractive Index Measurement ◽  
Iridocorneal Angle

Nowadays medicine highly relies on non-invasive optical diagnostic methods. The likewise situation is in the case of ophthalmology, especially in diagnosis of anterior segment eye diseases, where optical coherence tomography (OCT) plays inestimable role. OCT devices can do fast, painless measurements of the anterior segment of the eye. Nonetheless it should be remembered that the OCT images are burdened with an optical distortion and they doesn’t reflect the true geometry of the eye. This study presents an algorithm for correcting the distortion in OCT images and reflecting true parameters of the anterior segment of the eye. Full Text: PDF ReferencesA. Podoleanu, I. Charalambous, L. Plesea, A. Dogariu, R. Rosen, "Correction of distortions in optical coherence tomography imaging of the eye", Phys. Med. Biol. 49(7), 1277 (2004). CrossRef S. Ortiz, D. Siedlecki, I. Grulkowski, L. Remon, D. Pascual, M. Wojtkowski, S. Marcos, "Optical distortion correction in Optical Coherence Tomography for quantitative ocular anterior segment by three-dimensional imaging", Opt. Express 18, 2782 (2010). CrossRef F. LaRocca, S.J. Chiu, R.P. McNabb, A.N. Kuo, J.A. Izatt, S. Farsiu, "Robust automatic segmentation of corneal layer boundaries in SDOCT images using graph theory and dynamic programming", Biom. Opt. Express 2(6), 1524 (2011). CrossRef S.A. Read et al., "Anterior eye tissue morphology: Scleral and conjunctival thickness in children and young adults", Sci. Rep. 6, 33796 (2016). CrossRef S.R. Uhlhorn, D. Borja, F. Manns, J.-M. Parel, "Refractive index measurement of the isolated crystalline lens using optical coherence tomography", Vision Res., 48(27), 2732 (2008). CrossRef R. Koprowski, Z. Wróbel, S. Wilczyński, A. Nowińska, E. Wylęgała, "Methods of measuring the iridocorneal angle in tomographic images of the anterior segment of the eye", Biomed. Eng. Online, 12, 40 (2013). CrossRef D.P. Pinero, A.B. Plaza Puche, J.L. Alio, "Corneal diameter measurements by corneal topography and angle-to-angle measurements by optical coherence tomography: Evaluation of equivalence", J. Cataract Refract. Surg. 34, 126 (2008). CrossRef B. Urban, M. Krętowska, M. Szumiński, A. Bakunowicz-Łazarczyk, " Evaluation of anterior chamber depth measurements in emmetropic, hypermetropic and myopic eyes in children and adolescents using OCT Visante", Klinika Oczna 114(1), 18 (2012). DirectLink L. Chen, D. Chernyak, "Pupil Changes under Scotopic and Photopic illumination", Invest. Ophthalmol. Vis. Sci. 54, 1524 (2013). DirectLink D. Monsalvez-Romin, A.J. del Aguila-Carrasco, T. Ferrer-Blasco, J.J. Esteve-Taboada, R Montes-Mico, Evaluation of the iridocorneal angle with accommodation using optical coherence tomography", Int. J. Ophthalmol. 10(10), 1614 (2017). CrossRef

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