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> Anatomy > Body Part > Sclera

Sclera

Sclera: The tough, opaque, white outer layer of the eyeball that protects the inner structures and maintains the shape of the eye.
It is continuous with the cornea at the front of the eye and the connective tissue of the optic nerve at the back.
The sclera plays an important role in eye movement and provides attachment points for the extraocular muscles.
Understanding the structure and function of the sclera is crucial for diagnosing and treating eye disorders related to this critical component of the visual system.
Researcherrs can leverage PubCompare.ai's AI-driven platform to effortlessly locate and compare sclera-related research protocols from literature, preprints, and patents, streamlining their workflow and maximizing efficiency.

Most cited protocols related to «Sclera»

1
High-Precision Scleral Coil Tracking
Scleral coil voltages are filtered and amplified by ultra-low noise amplifiers (Analog Devices, AD8331) before digitization and demodulation. The AD8331 includes a single-ended pre-amplifier followed by a variable gain amplifier (VGA) and a selectable gain post-amplifier. A software command from a personal computer user interface sets VGA gain using a digital-to-analog converter (Texas Instruments, DAC7574). For the scleral coil design described above, the overall amplification is configured to provide ~100x gain of raw scleral coil signals. Bandpass filters are located at three stages throughout the amplification circuitry, with overall cutoff frequencies between 24 kHz and 1.5 MHz. After amplification, each coil’s amplified signal is digitized using a 12-bit, high-performance analog-to-digital converter (ADC, Texas Instruments, ADS5242). The FPGA then simultaneously samples up to 12 scleral coil signals at 25 Msamples/sec each and then demodulates them using a multiply accumulate (MAC) unit. This high sample rate improves noise performance via two variations on oversampling. First, the 25Msamples/S rate is about 4–8 times the Nyquist rate required for sampling the output of the 24kHz-1.5MHz bandpass preamplifiers. Oversampling by 22n = 4 times the Nyquist rate reduces ADC quantization noise and effectively adds n≈1 bit to the 12-bit ADC’s effective resolution, depending on the spectral content of the signal and the degree to which the noise is uncorrelated with the signal. [25 ],[26 ] The MAC unit multiplies each signal by three pseudo-sinusoids (with the same frequency and phase as the field) to extract each component of scleral coil angular position. To report X, Y, and Z coil signal components at a final rate of 1kSample/s, the FPGA performs a MAC operation over N=245, 498, and 763 cycles, respectively, of the scleral coil signal multiplied by the corresponding field coil driving signal. To the extent that noise at this stage in processing is uncorrelated with signals, this averaging would yield a √N≈16–28-fold reduction in noise amplitude relative to signal amplitude In addition to reduced noise, this approach also achieves much higher bandwidth relative to [14 (link)], which handled noise by passing analog-demodulated signals through a bank of 200Hz 8-pole Butterworth analog low-pass filters.. User interface software written in C and running on a PC acquires the demodulated signal at 1 kHz via a UM232H-B-NC serial-to-USB interface (Future Technology Devices International Limited).
The FPGA also provides digital pulse train driving signals for the magnetic fields. The pulsatile driving signals operate at 20% duty cycle to reduce high-current load on the MOSFET circuitry while generating strong enough fields to obtain a scleral coil signal well above the system’s noise floor. This duty cycle is software programmable. Adjusting it can increase field intensity, increasing signal strength for smaller scleral coils.
Hageman K.N., Chow M.R., Roberts D.C, & Della Santina C.C. (2020). Low-Noise Magnetic Coil System for Recording 3-Dimensional Eye Movements. IEEE transactions on instrumentation and measurement, 70, 1-9.
Publication 2020
Fingers Magnetic Fields Medical Devices Pulse Rate Sclera Sinusoidal Beds Strains
2
Choroidal Thickness Analysis using SD-OCT
The choroid was imaged using the EDI mode of SD-OCT (Spectralis, Heidelberg Engineering, Heidelberg, Germany). The macular region was scanned using a 7 horizontal line scan (30° × 5°) centred on the fovea, with 100 frames averaged in each B-scan. Each scan was 8.9 mm in length and spaced 240 μm apart from each other. In our study, Bruch’s membrane and the choroid-scleral interface were delineated with the automatic segmentation algorithm developed by Tian et al.35 (link) which demonstrated excellent repeatability in our previously reported population-based study36 (link). The choroidal thickness was automatically measured as the distance between the Bruch’s membrane (lower boundary of retinal pigmented epithelium [RPE]) and the choroid-scleral interface. Although measurements of both eyes of each study participant were obtained, due to inter eye correlation only the right eye was used for further analysis.
Agrawal R., Gupta P., Tan K.A., Cheung C.M., Wong T.Y, & Cheng C.Y. (2016). Choroidal vascularity index as a measure of vascular status of the choroid: Measurements in healthy eyes from a population-based study. Scientific Reports, 6, 21090.
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Publication 2016
Bruch Membrane Choroid Macula Lutea Radionuclide Imaging Reading Frames Retinal Pigment Epithelium Sclera
3
Choroid Explant Assay in Matrigel
Five minutes after injecting with Avertin, animals were checked for responses and euthanized by cervical dislocation. Eyes were immediately enucleated and kept in ice-cold medium before dissection. The choice of the medium was identical to the one used for incubation later. After removing the cornea and the lens from the anterior of the eye, the central or peripheral choroid-scleral complex was separated from the retina and cut into approximately ∼2 mm×1 mm pieces (rats) or 1 mm×1 mm (mice). Choroid/sclera (here on referred to as “choroid”) fragments were isolated with and without RPE removal by peeling RPE away with forceps and placed in growth factor-reduced Matrigel™ (BD Biosciences, Cat. 354230) seeded in 24 well plates (Supporting Video S1). 30 µL of matrigel was used to coat the bottom of 24 well plates without touching the edge of the well. The thickness of the matrigel was approximately 0.4 mm. After seeding the choroid, plates were incubated in a 37°C cell culture incubator without medium for 10 minutes in order for the Matrigel™ to solidify. 500 µL of medium was then added to each well and incubated at 37°C with 5% CO2 for 48 hr before any treatment. Medium was changed every 48 hr. Phase contrast photos of individual explants were taken daily using a ZEISS Axio Oberver.Z1 microscope. The areas of sprouting were quantified with computer software ImageJ 1.46r (National Institute of Health). The macro for SWIFT-Choroid quantification is available from the authors.
Shao Z., Friedlander M., Hurst C.G., Cui Z., Pei D.T., Evans L.P., Juan A.M., Tahir H., Duhamel F., Chen J., Sapieha P., Chemtob S., Joyal J.S, & Smith L.E. (2013). Choroid Sprouting Assay: An Ex Vivo Model of Microvascular Angiogenesis. PLoS ONE, 8(7), e69552.
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Publication 2013
Animals Cell Culture Techniques Choroid Cold Temperature Cornea Dissection Eye Forceps Growth Factor Joint Dislocations Lens, Crystalline matrigel Microscopy Microscopy, Phase-Contrast Mus Neck Rattus Retinal Detachment Sclera tribromoethanol
4
Magnetic Scleral Coil System for 3D Vestibulo-Ocular Reflex
The system comprises two major parts: magnetic field driver circuitry and signal demodulation circuitry, as shown in Fig. 1A–D. It records data from up to twelve scleral search coils. The system’s field coils refer to the coil frame itself, where each field coil pair, +X/−X (front/back), +Y/−Y (left/right), and +Z/−Z (up/down), are wired in pairs to make up the three orthogonal magnetic fields, X, Y and Z (following the right-hand rule). Each magnetic field oscillates at a unique frequency. Each field induces a voltage on each scleral coil. The three signals demodulated from each coil are proportional to the cosine of the angle between the scleral coil’s axis and the axes of each of the three field coils. With a set of two coils orthogonally attached to the sclera, the 3D VOR can be recorded and analyzed with 3D rotational kinematics equations described by Haslwanter and Migliaccio [23 (link)], [24 ].
Hageman K.N., Chow M.R., Roberts D.C, & Della Santina C.C. (2020). Low-Noise Magnetic Coil System for Recording 3-Dimensional Eye Movements. IEEE transactions on instrumentation and measurement, 70, 1-9.
Publication 2020
Epistropheus Magnetic Fields Reading Frames Sclera
5
Choroidal Vascular Measurement on SD-OCT

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Publication 2013
Arteries Blood Vessel Bruch Membrane Capillaries Choriocapillaris Choroid Eye Haller Layer Healthy Volunteers LINE-1 Elements Nose Postmortem Changes POU2F1 protein, human Radionuclide Imaging Sattler's Layer Sclera Tissues Veins

Most recents protocols related to «Sclera»

1
Senolytic Agent for Ophthalmic Conditions
Not available on PMC !

Example 11

This example provides an outline for a pre-clinical or clinical trial to evaluate the safety and efficacy of a senolytic agent for the treatment of ophthalmic conditions.

The senolytic is administered to subjects in the trial by standard intravitreal (ITV) administration technique, with the eye washed and draped in usual sterile fashion following pre-injection IOP measurement. Topical anesthesia is applied and a lid speculum placed for adequate exposure. The injection quadrant is chosen by the treating physician, and a location for the injection measured at 3 to 4 mm posterior to the corneo-scleral limbus. A 28-32-gauge needle is used to administer a 0.05 mL to 0.1 mL injection of the compound. The lid speculum is removed at the conclusion of the injection procedure. Depending on the nature of the condition, potentially suitable intra- or peri-ocular delivery methods include intravitreal, intracameral, posterior juxtascleral, subconjunctival or suprachoroidal injection.

Following the treatment, subjects are evaluated to determine whether symptoms or signs of the ophthalmic condition are improved, relative to subjects in a control group, using commonly available tests of ocular structure and function (supra).

US11865123B2. Methods of inhibiting pathological angiogenesis (2024-01-09). Unity Biotechnology, Inc. [US]. Inventors: Pam Tsuruda [US], Jill Hopkins [US], Harry Sweigard [US], Yan Poon [US], Jamie Dananberg [US], Daniel Marquess [US], Nathaniel David [US].
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Patent 2024
Eye Eye Disorders fluoromethyl 2,2-difluoro-1-(trifluoromethyl)vinyl ether Needles Obstetric Delivery Physicians Safety Sclera Speculum Sterility, Reproductive Topical Anesthetics
2
Diurnal Variation in Ocular Morphology
All measurements were performed on each subject without prior pupil dilation at three consecutive sessions (9 AM, 3 PM and 9 PM) within one day. An interval of six hours had to be between each measurement. One eye of each subject was chosen randomly before the first acquisition. To avoid fluctuations in blood pressure and heart rate, the measurements were taken each time after a waiting period of ten minutes in a sitting position and the participants were prohibited to consume caffeine prior to each visit. Each session included a high-resolution three-layer en face OCT-A scan of macula region (including SVP, ICP and DCP) and a high-speed OCT scan with enhanced depth imaging mode (EDI) to determine subfoveal CT, both by Heidelberg Spectralis II OCT (Heidelberg Engineering, Heidelberg, Germany). In addition, AL was measured with IOL master 500 (Carl Zeiss Meditec AG, Jena, Germany). All OCT-A scans were recorded on a 2.9 x 2.9 mm2 window with a 15° x 15° angle and a lateral resolution of 5.7 μm/pixel. Subfoveal CT was measured manually with a vertical distance between the hyperreflective line of Bruch’s membrane and the choroid-scleral interface.
Müller M., Schottenhamml J., Hosari S., Hohberger B, & Mardin C.Y. (2023). APSified OCT-angiography analysis: Macula vessel density in healthy eyes during office hours. PLOS ONE, 18(3), e0282827.
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Publication 2023
Blood Pressure Bruch Membrane Caffeine Choroid Face Macula Lutea Mydriasis Radionuclide Imaging Rate, Heart Sclera
3
3D-Printed Parametric Eyeball Model
The 3D-printed eyeball model was generated by CAD software and a simulation environment represented by ANSYS Workbench 19.1. In the current study, the eyeball consisted of the cornea, sclera, and vitreous humor to highlight the change in corneal thickness. The optical model was based on Gullstrand’s simplified schematic eye [3 ]. Fig 1a shows the structure and main components of the eye model, which is available as parameterizable CAD geometry. When we manufactured the eyeball, the “Material Jetting” style was used as an additive manufacturing. This process is as follows:
The material shore hardness is changed by the material jetting pattern. The output of the UV lamp and the rotational speed of the roller (600 rpm) were held constant during printing. This means that the material shore hardness is not changed by the output of the UV lamp and the speed of the roller.
To easily measure the IOP using a Tono-Pen AVIA tonometer (Reichert Inc., Depew, New York, USA), we created a cuboid eye holder. The aqueous and vitreous humor were simulated by the injection of hydrogels into the vitreous cavity. To induce different corneal stiffnesses, seven different CCTs were prepared for every 100-μm increase, and the curvatures of the cornea and sclera were simultaneously varied (Fig 1b). To simply control the change in the IOP, we changed only the CCT in the current study. Some parameters were fixed as the default values. To assess the deviation between the printed specimen and the CAD design, we aimed to measure the actual value of the CCT using an ultrasound pachymeter (SP-100; Tomey, Nagoya, Japan). Three consecutive measurements were performed in each eye model.
In addition to the design of the eye geometry, an adequate description of the material properties is required for the 3D-printing simulation. Table 1 shows the material parameters of the eye model.
Kobashi H, & Kobayashi M. (2023). 3D-printed eye model: Simulation of intraocular pressure. PLOS ONE, 18(3), e0282911.
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Publication 2023
ARID1A protein, human Cornea Cuboid Bone Dental Caries Hydrogels Sclera Ultrasonography Vision Vitreous Body
4
Retinal and RPE Flat Mount Staining

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Publication 2023
Alexa594 alexa fluor 488 anti-IgG Antibodies Biological Factors Choroid Cornea DAPI Goat Immunoglobulins Lens, Crystalline Microscopy, Confocal Novus Optic Disk Optic Nerve paraform Rabbits Retina Rod Opsins Sclera Serum Tween 20
5
Vortex Vein Characteristics in PCV and AMD
Patients orally agreed to the use of their data in the present study. Ethical approval for this retrospective study was obtained from the Institutional Review Board of the Zhongshan Ophthalmic Centre (approval no. 2022KYPJ173). In total, 180 participants(mean age, 64.12±8.87 years; range, 52-75 years) were recruited in this study, including 109 males and 71 females. All participants underwent ICGA (SPECTRALIS Diagnostic Imaging Platform; Heidelberg Engineering, Inc.) and optical coherence tomography (OCT) (SPECTRALIS® OCT; Heidelberg Engineering Inc.) between January 2018 and January 2022 at the Zhongshan Ophthalmic Centre, Guangzhou, China.
The present study included 63 patients with PCV, 50 with AMD and 67 healthy control group. Based on the results of fundus examination, OCT, fundus fluorescein angiography (FFA) and ICGA, age- and sex-matched patients were grouped based on diagnosis into PCV, AMD and healthy control group. Only one eye was included for patients diagnosed with bilateral PCV or AMD. In healthy participants, only the eye with the best-corrected visual acuity (>20/16) was included.
The following exclusion criteria were adopted: History of prior ocular surgery or trauma(excluded 15 PCV patients); severe vitreous haemorrhage that may affect imaging examination (excluded two PCV patients); any systemic disease that may affect blood flow, such as diabetes mellitus or hypertension (excluded one PCV patients and three AMD patients); central serous chorioretinopathy (CSC); primary glaucoma; optic neuritis; retinal vein occlusion; choroidal melanoma; retinal vasculitis; uveitis; an epiretinal membrane that may affect ocular circulation (excluded one PCV patients and five AMD patients) or moderate to high myopia (defined as a spherical equivalent refractive error in phakic eyes <-3.00 D) (excluded nine healthy participants).
We conducted another screening to exclude the cases who only received monocular ICGA and OCT examination and included 44 cases of unilateral PCV and 18 cases of unilateral AMD. The diseased eye was included in the PCV/AMD group, and the healthy fellow eye was included in the PCV/AMD fellow eye group.
Following intravenous injection of 5 ml 25 mg ICG (Dandong Yichuang Pharmaceutical Co., Ltd), ICGA images were recorded. Early-stage images (5 min after dye injection) were selected for analysis. The vortex veins were separated into four categories according to a previous method (8 (link)). The branches of type I vortex veins do not converge and pass directly through the sclera, whereas all branches of type IV (complete with ampulla) converge to form the ampulla, which is a complete vortex system. Type IV systems have a larger root area due to the dilated ampulla (8 (link)). The fundus was divided into four quadrants: Superior and inferior temporal and superior and inferior nasal. Patient characteristics, such as sex, age, number, location and type of vortex veins were recorded. The sketching tool of the retinal device was used to mark the root area and diameter of the thickest branch of each vortex vein (Fig. 1). The centre of a concentric circle was placed on the macula, the thickest vortex vein branch intersecting with the outermost circle was selected and its diameter was measured and stored as the central vortex vein diameter (CVVD). The ends of each vortex vein branch were connected with a smooth curve and the area enclosed by the curve was defined as the root area of the vortex vein (RAVV). The width of the thickest first-order branch of the vortex vein was defined as the diameter of the peripheral thickest branch (DPTB). The mean RAVV (MRAVV) and MDPTB were calculated. Vortex vein anastomosis was observed when vortex vein branches connected the two vortex vein systems on IGCA. The percentage of eyes with vortex vein anastomosis in each group was calculated and recorded as the percentage of vortex vein anastomosis (PVVA). Subfoveal choroidal thickness (SFCT) was measured using SPECTRALIS® OCT device. All labelling was performed separately by two experienced ophthalmologists (CXC and XMX) and the mean of the two measurements was used as the final data.
Cai C.X., Xiong X.M., Li T., Liu B.Q., Huang X.H., Yu S.S., Lin Z.Q., Wang Q., Cui J.L., Lu L, & Lin Y. (2023). Vortex vein engorgement and different shapes of venous drainage systems in polypoid choroidal vasculopathy vs. age‑related macular degeneration on indocyanine green angiography. Experimental and Therapeutic Medicine, 25(4), 162.
Publication 2023
Central Serous Chorioretinopathy Choroid Diabetes Mellitus Epiretinal Membrane Ethics Committees, Research Eye Females Fluorescein Angiography Glaucoma Healthy Volunteers High Blood Pressures Macula Lutea Males Medical Devices Melanoma Myopia Nose Ophthalmologists Optic Neuritis Patients Pharmaceutical Preparations Plant Roots Refractive Errors Retina Retinal Vasculitis Retinal Vein Occlusion Sclera Surgical Anastomoses Thalamostriate Veins Tomography, Optical Coherence Uveitis Veins Vision Visual Acuity Vitreous Hemorrhage Wounds and Injuries

Top products related to «Sclera»

1
Spectralis by Heidelberg Engineering
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The Spectralis is an optical coherence tomography (OCT) imaging device developed by Heidelberg Engineering. It captures high-resolution, cross-sectional images of the retina and optic nerve using near-infrared light. The Spectralis provides detailed structural information about the eye, which can aid in the diagnosis and management of various eye conditions.
2
Rneasy mini kit by Qiagen
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The RNeasy Mini Kit is a laboratory equipment designed for the purification of total RNA from a variety of sample types, including animal cells, tissues, and other biological materials. The kit utilizes a silica-based membrane technology to selectively bind and isolate RNA molecules, allowing for efficient extraction and recovery of high-quality RNA.
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TRIzol reagent is a monophasic solution of phenol, guanidine isothiocyanate, and other proprietary components designed for the isolation of total RNA, DNA, and proteins from a variety of biological samples. The reagent maintains the integrity of the RNA while disrupting cells and dissolving cell components.
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Penicillin/streptomycin is a commonly used antibiotic solution for cell culture applications. It contains a combination of penicillin and streptomycin, which are broad-spectrum antibiotics that inhibit the growth of both Gram-positive and Gram-negative bacteria.
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The LSM 710 is a laser scanning microscope developed by Zeiss. It is designed for high-resolution imaging and analysis of biological and materials samples. The LSM 710 utilizes a laser excitation source and a scanning system to capture detailed images of specimens at the microscopic level. The specific capabilities and technical details of the LSM 710 are not provided in this response to maintain an unbiased and factual approach.
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Nanofil syringe by World Precision Instruments
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Vectashield by Vector Laboratories
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Vectashield is a non-hardening, aqueous-based mounting medium designed for use with fluorescent-labeled specimens. It is formulated to retard photobleaching of fluorescent dyes and provides excellent preservation of fluorescent signals.
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Fv1000 by Olympus
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The FV1000 is a confocal laser scanning microscope designed for high-resolution imaging of biological samples. It features a modular design and advanced optics to provide clear, detailed images of cellular structures and processes.
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Spectralis hra oct by Heidelberg Engineering
Sourced in Germany, United States, Japan, United Kingdom
The Spectralis HRA+OCT is a multimodal imaging device that combines high-resolution fundus imaging with optical coherence tomography (OCT) technology. It allows for the simultaneous acquisition of detailed images of the retina, choroid, and optic nerve.

More about "Sclera"

The sclera is a critical component of the visual system, serving as the tough, opaque, white outer layer of the eyeball.
It protects the inner structures of the eye and maintains its shape, providing attachment points for the extraocular muscles that facilitate eye movement.
Researchers studying the sclera can utilize advanced tools and technologies to optimize their research protocols.
One such tool is the Spectralis HRA+OCT, a high-resolution imaging system that can be used to analyze the structure and function of the sclera.
The RNeasy Mini Kit and TRIzol reagent are commonly used for RNA extraction, while the Penicillin/streptomycin solution helps prevent bacterial contamination in cell cultures.
The LSM 710 confocal microscope and FV1000 imaging system are powerful tools for visualizing and analyzing scleral tissues.
To streamline the research process, scientists can leverage the AI-driven platform offered by PubCompare.ai.
This platform allows researchers to effortlessly locate and compare sclera-related research protocols from literature, preprints, and patents, saving time and maximizing efficiency.
The Nanofil syringe and Vectashield mounting medium can also be employed to facilitate tissue sampling and preservation, respectively.
By understanding the structure and function of the sclera and utilizing the right tools and technologies, researchers can gain valuable insights into eye disorders and develop more effective treatments.
The sclera's critical role in eye movement and its importance in maintaining the shape of the eye make it a crucial area of study for ophthalmologists and vision researchers alike.