What is confocal scanning laser ophthalmoscopy?
Confocal scanning laser ophthalmoscopy is a non–invasive investigation that has been used initially to receive three–dimensional images of the retinal surface in vivo. The commercial name of the device is Heidelberg Retina Tomograph (HRT). Two variants are used in current practice: HRT Ⅱ and HRT Ⅲ.
What is SLP for glaucoma?
Optical coherence tomography and scanning laser polarimetry (SLP) are the techniques that utilize the evaluation of RNFL for the evaluation of glaucoma. SLP provides RNFL thickness measurements based upon the birefringence of the retinal ganglion cell axons.
What is laser tomography?
Confocal Scanning Laser Tomography is a robust, sophisticated diagnostic technique which produces 3-dimensional laser scan images of the optic nerve head and gives three dimensional cross-sectional images of the retina.
What is a GDx scan?
The GDx is a scanning laser polarimetry device made by Laser Diagnostic Technologies (LDT) of San Diego. It gives you a direct measurement of the retinal nerve fiber layer (RNFL). The technique utilizes the birefringent properties of the nerve fibers that arise from their parallel anatomical organization.
What is Slo in ophthalmology?
confocal laser scanning microscopy (SLO) technology utilizes confocal laser scanning microscopy to create a high quality image of the retina. It is described as confocal because it employs a filter to block any out-of-focus light and produce a high-resolution image.
How many types of Ophthalmoscopy are there?
It is of two major types: Direct ophthalmoscopy one that produces an upright, or unreversed, image of approximately 15 times magnification. Indirect ophthalmoscopy one that produces an inverted, or reversed, image of 2 to 5 times magnification.
What is an OCT used for?
Optical coherence tomography (OCT) is a noninvasive imaging method that uses reflected light to create pictures of the back of your eye. It can be used to diagnose and manage diseases like diabetes-related retinopathy and glaucoma.
How does an OCT scanner work?
How Does OCT Work? OCT works similarly to an ultrasound. It provides real-time images of your eye’s internal structures like an ultrasound, but OCT uses light waves instead of sound waves. These light waves illuminate and scan your retina, giving your optometrist a detailed view.
What is GDx and where it is use in glaucoma?
The GDx maps the nerve fibers and compares them to a database of healthy, glaucoma-free patients. A thinning of the fibers indicates glaucoma. This information is then made available to your healthcare provider in the form of pictures, graphs and statistical data that indicate the probability of glaucoma.
What is HRT in Optometry?
Heidelberg Retinal Tomography is a diagnostic procedure used for precise observation and documentation of the optic nerve head, essential for the diagnosis and management of glaucoma. The HRT uses a special laser to take 3-dimensional photographs of the optic nerve and surrounding retina.
What is spectral domain OCT?
Optical coherence tomography (OCT) is a rapidly evolving, robust technology that has profoundly changed the practice of ophthalmology. Spectral domain OCT (SD-OCT) increases axial resolution 2- to 3-fold and scan speed 60- to 110-fold vs time domain OCT (TD-OCT).
What are the two types of ophthalmoscope?
There are two main types of ophthalmoscopes: direct and indirect. Direct ophthalmoscopes are simple hand-held ophthalmic instruments consisting of a concave mirror, a light source, an eye piece for the ophthalmic professional conducting the examination, and a simple handle.
When is ophthalmoscopy used?
Ophthalmoscopy is done as part of a routine physical or complete eye examination. It is used to detect and evaluate symptoms of retinal detachment or eye diseases such as glaucoma.
What can an OCT scan diagnose?
OCT is useful in diagnosing many eye conditions, including:
- macular hole.
- macular pucker.
- macular edema.
- age-related macular degeneration.
- central serous retinopathy.
- diabetic retinopathy.
- vitreous traction.
Is MRI a OCT?
In contrast to MRI, the possible uses of OCT are more limited as it allows, from a strict scientific point of view, only a scan of the retina and measurement of its total thickness/volume or of individual retinal layers.
What is nerve fiber in the eye?
In the mature eye, the optic nerve fiber layer of the retina consists of the axonal processes of ganglion cells that are directed toward the optic papilla and emerge from the eye as the optic nerve.
What is the nerve fiber analysis?
A nerve fiber analysis test will detect any damage to the nerve fiber layer around the optic nerve due to glaucoma. This process is painless and takes approximately five minutes. The test consists of a scanning laser used to measure the thickness of the nerve fiber layer around the optic nerve.
What is retinal scanning laser polarimetry?
In Retinal scanning laser polarimetry (SLP), the cornea, lens, and retina are all treated as linear retarders (optical elements that introduce retardation to an illuminating beam).
What is confocal scanning laser polarimetry?
The principle of confocal scanning laser polarimetry is to illuminate the optic nerve and retina through a single pinhole and to allow light that returns from the point of interest to pass through the pinhole and be detected.
What is laser polarimetry used for?
Scanning laser polarimetry. A scanning unit in this instrument is used to move the beam horizontally and vertically on the retina. The focused beam is 35μm in diameter. This instrument also has a polarization detector. It is used to detect polarized light that is reflected back from the cornea.
What is linear retarder in laser polarimetry?
In Retinal scanning laser polarimetry (SLP), the cornea, lens, and retina are all treated as linear retarders (optical elements that introduce retardation to an illuminating beam). A linear retarder has a slow axis and a fast axis, and the two axes are orthogonal to each other.