Scanning laser polarimetry slp, a technology for glaucoma diagnosis, uses imaging polarimetry to detect the birefringence of the retinal nerve fiber layer. Confocal scanning laser ophthalmoscopy is a technique designed to evaluate the threedimensional structure of the optic disc, which has been described in chapter. Analytical methods for scanning laser polarimetry osa. Aims to evaluate the reproducibility of the retardation values change in polarisation obtained with the scanning laser polarimeter in a series of normal subjects and glaucoma patients. Corneal birefringence affects polarizationsensitive optical measurements of the eye. Scanning laser polarimetry slp is based on the birefringence properties of ganglion cell axon neurotubules that alter the laser scanning beam polarization acco rding to the rnfl thickness. Zeiss gdx pro 8000 is the only commercially available, currentgeneration scanning laser polarimeter. Pdf to determine the correlations and strength of association between different imaging systems in analyzing the retinal nerve fiber layer rnfl of. Hence, the measurement of rnfl thickness has come up.
Scanning laser polarimetry slp utilizes a scanning laser ophthalmoscope to determine the peripapillary rnfl thickness, pixel by pixel, by measuring the total retardation of polarized light reflected from the retina. Measurement of the retinal nerve fibre layer with scanning. Pdf to compare the abilities of scanning laser polarimetry with the variable corneal compensator gdx vcc with those of optical coherence. Scanning laser polarimetry is performed by a confocal scanning laser ophthalmo scope with an integrated polarimeter gdxvcc. Gdxpro uses a nearinfrared laser 780nm in a raster pattern to image the macula and peripapillary region. Scanning laser polarimetry images were obtained using a commercial gdx vcc system version 5. Optical coherence tomography, scanning laser polarimetry. Technology today the nerve fiber layer and scanning. It utilizes the birefringent properties of the rnfl, which produces a change in polarization called retardation of the light reflected by the rnfl.
Scanning laser polarimetry in eyes with exfoliation syndrome article pdf available in european journal of ophthalmology 235 march 20 with 34 reads how we measure reads. Methods scanning laser polarimetry was performed on 10 normal subjects and 10 glaucoma. This study measured corneal retardation in eyes with a wide range of central corneal retardance by means of. Optical coherence tomography oct shows retinal nerve. Scanning laser polarimetry was developed at the university of california, san diego, and introduced as a commercial instrument by laser diagnostic technologies san diego, ca. Diagnostic capabilities of frequencydoubling technology, scanning laser polarimetry, and nerve fiber layer photographs to distinguish glaucomatous damage. Several studies with optical coherence tomography oct have demonstrated thinning of the retinal nerve fiber layer rnfl in patients with optic neuritis and multiple sclerosis. The effects of poor anterior segment compensation on scanning laser polarimetry measurements of.
Scanning laser polarimetry an overview sciencedirect. Optical coherence tomography and scanning laser polarimetry slp are the techniques that utilize the. For example, the rtvue xr oct avanti optovue is an oct system. Objective to determine if scanning laser polarimetry slp measures form birefringence of the retinal nerve fiber layer rnfl. Scanning laser polarimetry of the retinal nerve fiber layer. Department of ophthalmology, santa maria della misericordia hospital, udine, italy. It uses both a polarimeter an optical device to measure linear polarization change and a scanning laser ophthalmoscope, to measure the thickness of the nerve fiber layer of the retina. Scanning laser polarimetry and spectral domain optical coherence. Ophthalmologic techniques that evaluate the posterior. Scanning laser polarimetry slp has been proposed as a rapid, objective and reproducible technology for retinal nerve fiber layer rnfl assessment and clinical studies have demonstrated that slp can help to distinguish between normal andglaucomatous eyes, identify glaucoma suspects and correlates well with visual field defects. To characterize which clinical features are associated with the occurrence of atypical birefringence patterns abp occasionally seen with scanning laser polarimetry slp. Description carl zeiss scanning laser polarimetry gdxpro 8000.
Retinal ganglion cells and their axons represent the. Scanning laser polarimetry versus matrix perimetry, optical coherence tomography, and retinal nerve fiber layer photography using heidelberg retina angiograph 1. Gdxpro scaning laser polarimetry glaucoma carl zeiss. As it goes through tubules, it returns at a different orientation axis.
Although these techniques are different, their objective is the same. Scanning laser polarimetry reveals status of rnfl integrity in eyes with optic nerve head swelling by oct mark j. To image a plane, rather than a point, an array of points in that plane must be scanned point by point yielding an optical plane or section. Methodssix eyes of six normal volunteers and an artificial nerve fibre layer were examined using the nerve fibre analyser. Though the technology has been available for several years, recent advances have resulted in improved imaging capabilities that may enhance clinicians ability to identify and follow the progression of glaucoma.
Scanning laser polarimetry measures change in the linear polarization of light retardation. Scanning laser polarimetry slp for optic nerve head. A basic understanding of how birefringence and retardation is vital to understand how this tech pictures the optic nerve. Similar studies have not been performed with scanning laser polarimetry slp, which relies on d. To develop a quantitative understanding of scanning laser polarimetry slp for retinal nerve fiber layer rnfl assessment in glaucoma diagnosis. Pdf optical coherence tomography, scanning laser polarimetry. Detection of glaucoma using scanning laser polarimetry with. Ophthalmic surgery, lasers and imaging retina abstract.
This study was carried out to assess the prevalence, extent, and pattern of rnfl loss after demyelinating optic neuritis using slp. The rnfl in the macula is very thin and should contribute no signal to scanning laser polarimetry. Scanning laser polarimetry quantification of retinal nerve. To improve the analysis of the raw data by devising and evaluating a blood vessel removal algorithm. Aims to devise a method to describe and quantify the shape of polar profiles obtained with the scanning laser polarimeter and to compare this measurement with other polar profile measurements in a series of normal subjects and glaucoma patients. Analytical model of scanning laser polarimetry for retinal nerve.
Technology today the nerve fiber layer and scanning laser. Effects of artefacts on scanning laser polarimetry of. Although these techniques differ, the objective is the. Pdf evaluation of retinal nerve fiber layer using scanning laser. 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. Comparison between gdx vcc scanning laser polarimetry and. Scanning laser polarimetry with variable and enhanced. Near infrared wavelength laser double passes the retinal nerve fiber layer nfl and is split into 2 parallel rays by the birefringent fibers. We describe the application of a scanning laser polarimeter for quantitative measurements of the retinal nerve fiber layer thickness in vivo. It uses the technique of confocal laser scanning microscopy for diagnostic imaging of retina or cornea of the human eye as a method used to image the retina with a high degree of spatial sensitivity, it is helpful in the diagnosis of glaucoma, macular degeneration, and other retinal disorders. Optic nerve and retinal nerve fiber imaging eyewiki. One creative approach to this problem was based on the known anatomy of the normal retina. Scanning laser polarimetry is a diagnostic method that has been developed to measure quantitatively the thickness of the peripapillary retinal nerve fiber layer rnfl. Scanning computerized ophthalmic diagnostic imaging devices.
Scanning laser polarimetry, retinal birefringence, light retardation, retinal nerve fiber layer, glaucoma, anterior segment birefringence. Comparison between gdx vcc scanning laser polarimetry and stratus oct optical coherence tomography in the diagnosis of chronic glaucoma. Detection of glaucoma with scanning laser polarimetry glaucoma. Scanning laser polarimetry definition of scanning laser. The main birefringent intraocular tissues are the cornea, lens and the retina. Scanning laser polarimetry slp is a confocal scanning laser ophthalmoscope with an integrated polarimeter that measures the amount of retardation phase shift of a polarized nearinfrared laser beam as it passes through the rnfl. Local coverage determination for scanning computerized. Corneal birefringence mapped by scanning laser polarimetry.
Optical coherence tomography, scanning laser polarimetry and confocal scanning laser ophthalmoscopy in retinal nerve fiber layer measurements of glaucoma patients farsad fanihagh, 1 stephan kremmer, 1, 2 gerasimos anastassiou, 1, 2 and maurice schallenberg 2, 3. Scanning laser polarimetry slp is an imaging technology designed to provide objective assessment of the thickness of the retinal nerve fiber layer rnfl, with. Scanning laser polarimetry slp was developed to provide objective assessment of the retinal nerve fiber layer rnfl, a birefringent tissue, by measuring the total retardation in the reflected light. Scanning laser polarimetry laser light enters eye at specific orientation. Pdf scanning laser polarimetry in eyes with exfoliation. A number of confocal scanning laser ophthalmoscopy, scanning laser polarimetry, and optical coherence tomography oct devices have been cleared by the u. The oct scans of the onh and the rnfl were obtained with the fast.
Scanning laser polarimetry is a technique for assessing the thickness of the retinal nerve fiber layer in vivo. The scanning laser ophthalmoscope differs from scanning laser polarimetry in that the slo measures the topography, or estimates the height of the retina, while scanning laser polarimetry directly measures the thickness of the retinal nerve fiber layer by use of polarization. Scanning laser polarimetry assesses peripapillary rnfl thickness. Scanning laser polarimetry in pulmonary tuberculosis. Recent literature supports the idea that corneal birefringence is biaxial, although with some disagreement among reports and without considering corneas with very low values of central retardance. Scanning laser polarimetry slp is a confocal scanning laser ophthalmoscope with an integrated polarimeter that measures the amount of retardation phase shift of a polarized, nearinfrared laser beam as it passes through the retinal nerve fiber layer rnfl 6, 12, 1822. Automatic mapping to an automatically generated ip address.
Assessment of nerve fiber layer in diabetic patients with. Factors affecting image acquisition during scanning laser. Longterm followup of scanning laser polarimetry and confocal scanning laser ophthalmoscopy in normal tension glaucoma kremmer s 1,2, darwesh s 2, anastassiou g 1,2, steuhl kp and selbach jm1,2 1eye hospital, evangelisches krankenhaus gelsenkirchen, munckelstr. Scanning laser polarimetry and spectral domain optical coherence tomography for the detection of retinal changes in parkinsons disease. Dicom gateway for compatibility with zeiss networking solutions. Objective to evaluate the effects of diabetes mellitus, diabetic retinopathy and degree of blood glucose bg regulation on retinal nerve fiber layer rnfl thickness by using a scanning laser. Objectiveto determine which retinal nerve fiber layer rnfl measures obtained with scanning laser polarimetry are most useful in detecting early to moderate. Kupersmith,1 randy kardon,2 mary durbin,3 melissa horne,3 and julia shulman4 purpose. Osa analytical methods for scanning laser polarimetry. Scanning laser polarimetry is an imaging technology that is utilized to measure peripapillary rnfl thickness.
The birefringence of the anterior segment of the eye, mainly the. In all subjects, both eyes were scanned with the gdx vcc, starting with the right eye. Aimsto investigate the effects of artefacts on scanning laser polarimetry of the retinal nerve fibre layer. However a dutch study found that while there is a correlation between standard automa ted perim etry and gdx vcc measurements in patients with glaucoma, suggesting that gdx. Pdf comparison between gdx vcc scanning laser polarimetry. These results are often considered along with other findings to make diagnostic and therapeutic decisions. The commercially available scanning laser ophthalmoscope is made by heidelberg engineering, and is called the heidelberg retinal tomography hrt. Scanning laser polarimetry an overview sciencedirect topics. Gdxpro, the worlds only scanning laser polarimeter, provides a unique measurement derived from both rnfl thickness and rnfl structural organization. A simple model of slp suggests an algorithm for calculating birefringence that, unlike previous methods, uses all of the data available in the images to achieve better signaltonoise ratio and lower sensitivity to depolarization. It therefore differs in terms of its physical basis from the interferometry method of oct. Gdxpro scaning laser polarimetry glaucoma carl zeiss meditec international.
An observation of unusual retinal patterns under certain optical condi. In hong kong, there are about 7000 new cases of pulmonary. Scanning laser polarimetry slp is a new image analysis technique which uses the polarising properties of the retinal nerve fibre layer rnfl to produce a quantitative measure of its thickness. Clinical characteristics of eyes demonstrating atypical. Scanning laser polarimetry may have good sensitivity and specificity for separating normal from abnormal eyes, but it is not as good for classifying unknown subjects when glaucoma suspects are. Methods consecutive patients with either acute unilateral disc edema or chronic diffuse unilateral disc atrophy underwent slp using the gdx nerve fiber. Scanning laser polarimetry slp, a technology for glaucoma diagnosis, uses. Detection of glaucoma with scanning laser polarimetry. Many forms of scanning computerized ophthalmic diagnostic imaging tests currently exist e. Scanning laser polarim etry is the use of polar ised light to measure the thickness of the retinal nerve fiber layer as part of a glaucoma workup. This technology grew out of efforts to improve scanning laser ophthalmoscopy. Food and drug administration fda through the 510k process for imaging the posterior eye segment. Effects of inadequate anterior segment compensation on.
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