This document discusses fundus autofluorescence, which maps the metabolic function of the retinal pigment epithelium (RPE). It explains that lipofuscin, a byproduct of phagocytosis in the RPE, is a major source of autofluorescence. Increased lipofuscin accumulation is implicated in aging and retinal diseases. Fundus autofluorescence imaging allows evaluation of spatial and temporal changes in lipofuscin distribution, providing insight into disease progression and prognosis. Specific autofluorescence patterns are described for various retinal conditions, and its utility for monitoring treatment effects is discussed.
1) Fundus autofluorescence imaging provides a noninvasive method to map naturally occurring fluorophores in the eye. The major source of fundus autofluorescence is lipofuscin in the retinal pigment epithelium and melanin.
2) Lipofuscin accumulation over time can be toxic to retinal pigment epithelium cells and interfere with normal cell function. Areas of geographic atrophy in age-related macular degeneration appear as dark regions due to the lack of retinal pigment epithelium and lipofuscin.
3) Abnormal patterns of fundus autofluorescence such as banded or diffuse patterns are associated with more rapid progression of geographic atrophy compared to areas without abnormalities or those with only
Glaucoma is a chronic optic neuropathy and a leading cause of blindness worldwide. Structural changes to the optic disc can be detected earlier than functional vision loss, so assessing the disc is crucial. The Disc Damage Likelihood Scale (DDLS) was developed to incorporate disc size and focal rim width into grading glaucomatous damage. The DDLS provides a quantitative method for diagnosing, staging, and monitoring glaucoma progression. While it has limitations for some disc types, the DDLS correlates well with visual field loss when used properly.
Update knowledge about Muntifocal IOL made by Asaduzzaman
Working as Associate Optometrist in Ispahani Islamia Eye Institute &Hospita, Dhaka 1215
Email:asad.optom92@yaho. com
This document discusses various techniques and considerations for phacoemulsification cataract surgery. It covers traditional and modern power modes to maximize efficiency while minimizing energy dispersed in the eye. It also discusses fluidic concepts like inflow, outflow and maintaining anterior chamber stability to avoid surge and minimize damage. Different pump types like peristaltic and venturi are compared in terms of vacuum safety and fragment capture ability. Nucleus removal techniques like divide and conquer, stop and chop, and quick chop are outlined. Maintaining a safe central zone and matching instrument size to incision size are also recommended.
This document discusses contact lenses, including their classification based on anatomical position, material, and mode of wear. It covers topics such as contact lens design, related terms, ideal materials, indications for use, contraindications, and optics. Rigid and soft contact lenses are described. Factors that affect contact lens fit and comfort are also summarized.
Este documento trata sobre la degeneración macular asociada a la edad (DMAE), su diagnóstico y tratamiento a lo largo de los años. Describe las diferentes técnicas utilizadas como la angiografía con fluoresceína y verde de indocianina, fotocoagulación láser, terapia fotodinámica y más recientemente anti-VEGF y OCT. Explica la clasificación y componentes de las membranas neovasculares asociadas a la DMAE.
This document provides information about optical biometry and the IOL Master device. It discusses the principles and history of optical interferometry, intended uses of the IOL Master including axial length measurement, corneal curvature measurement, and IOL power calculation. Screen layouts and measurements taken by the IOL Master are described. Advantages include highly accurate and non-contact measurements, while limitations include inability to measure in cases of severe media opacities or poor patient cooperation.
This document discusses fundus autofluorescence, which maps the metabolic function of the retinal pigment epithelium (RPE). It explains that lipofuscin, a byproduct of phagocytosis in the RPE, is a major source of autofluorescence. Increased lipofuscin accumulation is implicated in aging and retinal diseases. Fundus autofluorescence imaging allows evaluation of spatial and temporal changes in lipofuscin distribution, providing insight into disease progression and prognosis. Specific autofluorescence patterns are described for various retinal conditions, and its utility for monitoring treatment effects is discussed.
1) Fundus autofluorescence imaging provides a noninvasive method to map naturally occurring fluorophores in the eye. The major source of fundus autofluorescence is lipofuscin in the retinal pigment epithelium and melanin.
2) Lipofuscin accumulation over time can be toxic to retinal pigment epithelium cells and interfere with normal cell function. Areas of geographic atrophy in age-related macular degeneration appear as dark regions due to the lack of retinal pigment epithelium and lipofuscin.
3) Abnormal patterns of fundus autofluorescence such as banded or diffuse patterns are associated with more rapid progression of geographic atrophy compared to areas without abnormalities or those with only
Glaucoma is a chronic optic neuropathy and a leading cause of blindness worldwide. Structural changes to the optic disc can be detected earlier than functional vision loss, so assessing the disc is crucial. The Disc Damage Likelihood Scale (DDLS) was developed to incorporate disc size and focal rim width into grading glaucomatous damage. The DDLS provides a quantitative method for diagnosing, staging, and monitoring glaucoma progression. While it has limitations for some disc types, the DDLS correlates well with visual field loss when used properly.
Update knowledge about Muntifocal IOL made by Asaduzzaman
Working as Associate Optometrist in Ispahani Islamia Eye Institute &Hospita, Dhaka 1215
Email:asad.optom92@yaho. com
This document discusses various techniques and considerations for phacoemulsification cataract surgery. It covers traditional and modern power modes to maximize efficiency while minimizing energy dispersed in the eye. It also discusses fluidic concepts like inflow, outflow and maintaining anterior chamber stability to avoid surge and minimize damage. Different pump types like peristaltic and venturi are compared in terms of vacuum safety and fragment capture ability. Nucleus removal techniques like divide and conquer, stop and chop, and quick chop are outlined. Maintaining a safe central zone and matching instrument size to incision size are also recommended.
This document discusses contact lenses, including their classification based on anatomical position, material, and mode of wear. It covers topics such as contact lens design, related terms, ideal materials, indications for use, contraindications, and optics. Rigid and soft contact lenses are described. Factors that affect contact lens fit and comfort are also summarized.
Este documento trata sobre la degeneración macular asociada a la edad (DMAE), su diagnóstico y tratamiento a lo largo de los años. Describe las diferentes técnicas utilizadas como la angiografía con fluoresceína y verde de indocianina, fotocoagulación láser, terapia fotodinámica y más recientemente anti-VEGF y OCT. Explica la clasificación y componentes de las membranas neovasculares asociadas a la DMAE.
This document provides information about optical biometry and the IOL Master device. It discusses the principles and history of optical interferometry, intended uses of the IOL Master including axial length measurement, corneal curvature measurement, and IOL power calculation. Screen layouts and measurements taken by the IOL Master are described. Advantages include highly accurate and non-contact measurements, while limitations include inability to measure in cases of severe media opacities or poor patient cooperation.
Phacodynamics refers to the fundamental principles of inflow, outflow, vacuum, and phaco power modulation during cataract surgery. Understanding these principles helps optimize machine settings for different surgical techniques. The foot pedal controls irrigation, aspiration, and ultrasound energy. Position 1 provides irrigation only, position 2 adds aspiration, and position 3 engages ultrasound. Peristaltic and venturi pumps differ in how they create vacuum. Peristaltic pumps require tip occlusion while venturi pumps create vacuum instantly. Factors like compliance, surge, and vent type impact fluidics and safety. Mastering phacodynamics leads to independent surgical skill.
This document discusses using optical coherence tomography (OCT) to analyze the macula, retinal nerve fiber layer (RNFL), and optic nerve head in patients with glaucoma or suspected glaucoma. It describes how OCT can measure macular thickness, RNFL thickness, and optic disc parameters. Five case studies are presented showing how structural changes seen on OCT correlate with functional defects on visual field tests or clinical findings. The document concludes by mentioning Doppler OCT may help understand the role of blood flow in glaucoma and other optic neuropathies.
The document discusses various types of optical aberrations that can occur in the eye. It describes monochromatic aberrations, which are caused by the geometry of the lens, and chromatic aberrations, which are caused by dispersion and the variation of the lens refractive index with wavelength. It also discusses how wavefront aberrometry can be used to measure aberrations by analyzing the distortion of reflected light to generate a map of the optical system of the eye. Common higher-order aberrations measured include coma, spherical aberration, and trefoil.
This document discusses various imaging techniques used to evaluate glaucoma, including OCT, HRT, and GDx. OCT uses interferometry to measure retinal nerve fiber layer thickness. HRT uses confocal laser scanning to create 3D images of the optic nerve and measure disc parameters. GDx uses scanning laser polarimetry to measure retinal nerve fiber layer thickness and detect glaucomatous damage through thickness maps, deviation maps, and TSNIT plots compared to normative data. Together these quantitative imaging techniques provide objective assessment to aid in glaucoma diagnosis and detection of progression.
Optical and Non-optical Methods of Measuring Axial Length of EyeRabindraAdhikary
This document discusses various optical and non-optical methods of measuring axial length of the eye. It begins by defining axial length and noting its importance in intraocular lens power calculations. It then describes ultrasonic (A-scan) biometry, the historical standard, and optical biometry techniques like partial coherence interferometry used in devices like the IOLMaster 500. Key advantages of optical techniques are discussed as well as limitations of ultrasound. Details are provided on performing both immersion and non-immersion ultrasound techniques and interpreting the results.
This document discusses automated perimetry, which is used to evaluate the visual field. It begins by explaining the importance of perimetry in diagnosing and monitoring glaucoma and other conditions. It then defines key concepts like the visual field and hill of vision. The document discusses the components and procedures of automated perimetry testing, including factors that influence the results like stimulus characteristics, fixation monitoring, and testing strategies. It describes different perimetry tests and their applications in evaluating various eye diseases. In summary, the document provides an overview of automated perimetry, its role in eye care, and the technical aspects of performing this important visual field assessment test.
Biosimilars IN RETINAL DISORDERS -DR AJAY DUDANIAjayDudani1
This document discusses the treatment of retinal conditions with a focus on anti-VEGF therapies. It provides a history of the development of anti-VEGF treatments from the discovery of VEGF in the 1980s and 1990s to the approval of ranibizumab and aflibercept in the 2000s. It then discusses the evolution of ranibizumab and the evidence from clinical trials supporting its use. Finally, it addresses biosimilars that are attempting to enter the anti-VEGF market and highlights some of the differences between biosimilars and innovator biologics.
Curso impartido en SECOIR 2017 por el Dr Alvaro Rodríguez Ratón actualizando las tecnologías de biometría, topografía y tomografía. Incluye IOLmaster, Lenstar, Aladdin, Pentacam, Sirius, Galilei, Argos ...
femtosecond laser in ophthalmology by Dr. Hind Safwat (Al Azhr university) Hind Safwat
Here are the key points about FSL in penetrating keratoplasty:
- FSL allows for precise, consistent cuts that minimize damage to surrounding tissue.
- It can create wound configurations that provide more surface area for healing, improve tissue alignment, require less suture tension, and have superior biomechanical strength.
- Advantages include rapid visual recovery, less astigmatism, and benefits specific to the type of cut (lamellar vs penetrating).
- Contraindications include conditions preventing proper docking of the laser such as severe ocular surface irregularities or recent perforations.
Dry age-related macular degeneration (AMD) is the leading cause of irreversible vision loss among people over 65. It is characterized by the breakdown and loss of cells in the macula due to aging and can be categorized as either dry or wet AMD. Dry AMD accounts for 90% of cases and results in gradual vision loss over time due to buildup of drusen and development of geographic atrophy in the macula. Diagnosis is based on the presence of soft or large drusen, pigmentary abnormalities, and atrophy seen on examination and imaging like OCT. There is no cure for dry AMD and vision loss progresses slowly, resulting in central blind spots.
This document summarizes key information about hard contact lenses, including their advantages, disadvantages, indications for use, and fitting procedures. Hard contact lenses are made of PMMA or similar materials. They are durable, have a long lifespan, provide clear vision, and only require one fitting visit. However, they can be uncomfortable, fall out, break, or warp. Common uses are for astigmatism, aphakia, keratoconus, and during certain medications. The fitting process involves keratometry, trial lenses, adjusting for diameter, base curve, and power. Proper centration, lens movement, and hygiene are important to avoid problems.
Multifocal IOLs provide both near and distance vision without glasses by utilizing concentric zones of different optical powers (refractive MFIOLs) or diffractive properties to split light between two focal points. While eliminating need for glasses, they can cause visual side effects like glare and reduced contrast sensitivity. Careful patient selection and counseling, accurate biometry and surgical technique are important for successful multifocal IOL implantation outcomes.
Optical coherence tomography (OCT) is useful for imaging both the anterior and posterior segments in glaucoma. Posterior segment OCT allows quantification of retinal nerve fiber layer thickness, optic nerve head parameters, and ganglion cell layer thickness. Changes in these measurements over time can help detect glaucomatous progression. Anterior segment OCT visualizes angle anatomy and structures after glaucoma surgery. OCT provides objective data but results must be interpreted carefully while considering limitations such as variability between devices and lack of representation in normative databases.
1) A 76-year-old male presented with decreased vision in the right eye due to neovascular AMD. He underwent 6 injections of ranibizumab in the right eye, which showed a good response.
2) On subsequent follow-up, the left eye developed subretinal fluid and increased PED size, and was treated with ranibizumab injection. A retinal pigment epithelium (RPE) tear developed in the left eye within days of the injection.
3) RPE tears are a known complication of anti-VEGF treatment for neovascular AMD, occurring in 5-19.7% of cases. Taller PED height and greater linear diameter are risk factors
OCT is used to non-invasively image the retina in cross-section with micrometer-level resolution. It works by measuring the interference of light reflected from retinal structures. OCT was developed in 1991 and uses near-infrared light wavelengths of 840nm and 1310nm. OCT provides high-resolution 2D images of the retina and can integrate data points over depth to form 3D representations. It is useful for diagnosing and monitoring many retinal diseases.
National Ocular Biometry Course (NOBC) 2015 An echoslide presentation Anis Suzanna Mohamad
This powerpoint presentation is basically about ocular biometry. Echo presentation is one of the method to deliver infomation that obtain from the course we attend to other staff in our Ophthalmology Department.
This document discusses different types of multifocal intraocular lenses (IOLs) used in cataract surgery. There are three main types: refractive, diffractive, and a combination. Refractive IOLs use concentric rings of different optical powers while diffractive IOLs use diffraction optics to create two focal points. Combination IOLs can provide the advantages of both refractive and diffractive technologies. The document also covers specific multifocal IOL models and considerations for patient selection.
This document provides an overview of the basics of phacoemulsification including machine technology, irrigation and aspiration handpieces, peristaltic pumps, venturi pumps, foot pedal functions, and power variables. Key points include:
- Phacoemulsification uses ultrasonic energy from a piezoelectric crystal to emulsify cataracts.
- Machine technology includes ultrasonic handpieces, irrigation/aspiration tips, and peristaltic or venturi pumps to provide vacuum.
- The foot pedal controls irrigation only, irrigation with aspiration, or full function with ultrasound emission.
- Power is determined by factors like nucleus density, tip engagement, and linear tip velocity to safely sculpt
Phacodynamics refers to the fundamental principles of inflow, outflow, vacuum, and phaco power modulation during cataract surgery. Understanding these principles helps optimize machine settings for different surgical techniques. The foot pedal controls irrigation, aspiration, and ultrasound energy. Position 1 provides irrigation only, position 2 adds aspiration, and position 3 engages ultrasound. Peristaltic and venturi pumps differ in how they create vacuum. Peristaltic pumps require tip occlusion while venturi pumps create vacuum instantly. Factors like compliance, surge, and vent type impact fluidics and safety. Mastering phacodynamics leads to independent surgical skill.
This document discusses using optical coherence tomography (OCT) to analyze the macula, retinal nerve fiber layer (RNFL), and optic nerve head in patients with glaucoma or suspected glaucoma. It describes how OCT can measure macular thickness, RNFL thickness, and optic disc parameters. Five case studies are presented showing how structural changes seen on OCT correlate with functional defects on visual field tests or clinical findings. The document concludes by mentioning Doppler OCT may help understand the role of blood flow in glaucoma and other optic neuropathies.
The document discusses various types of optical aberrations that can occur in the eye. It describes monochromatic aberrations, which are caused by the geometry of the lens, and chromatic aberrations, which are caused by dispersion and the variation of the lens refractive index with wavelength. It also discusses how wavefront aberrometry can be used to measure aberrations by analyzing the distortion of reflected light to generate a map of the optical system of the eye. Common higher-order aberrations measured include coma, spherical aberration, and trefoil.
This document discusses various imaging techniques used to evaluate glaucoma, including OCT, HRT, and GDx. OCT uses interferometry to measure retinal nerve fiber layer thickness. HRT uses confocal laser scanning to create 3D images of the optic nerve and measure disc parameters. GDx uses scanning laser polarimetry to measure retinal nerve fiber layer thickness and detect glaucomatous damage through thickness maps, deviation maps, and TSNIT plots compared to normative data. Together these quantitative imaging techniques provide objective assessment to aid in glaucoma diagnosis and detection of progression.
Optical and Non-optical Methods of Measuring Axial Length of EyeRabindraAdhikary
This document discusses various optical and non-optical methods of measuring axial length of the eye. It begins by defining axial length and noting its importance in intraocular lens power calculations. It then describes ultrasonic (A-scan) biometry, the historical standard, and optical biometry techniques like partial coherence interferometry used in devices like the IOLMaster 500. Key advantages of optical techniques are discussed as well as limitations of ultrasound. Details are provided on performing both immersion and non-immersion ultrasound techniques and interpreting the results.
This document discusses automated perimetry, which is used to evaluate the visual field. It begins by explaining the importance of perimetry in diagnosing and monitoring glaucoma and other conditions. It then defines key concepts like the visual field and hill of vision. The document discusses the components and procedures of automated perimetry testing, including factors that influence the results like stimulus characteristics, fixation monitoring, and testing strategies. It describes different perimetry tests and their applications in evaluating various eye diseases. In summary, the document provides an overview of automated perimetry, its role in eye care, and the technical aspects of performing this important visual field assessment test.
Biosimilars IN RETINAL DISORDERS -DR AJAY DUDANIAjayDudani1
This document discusses the treatment of retinal conditions with a focus on anti-VEGF therapies. It provides a history of the development of anti-VEGF treatments from the discovery of VEGF in the 1980s and 1990s to the approval of ranibizumab and aflibercept in the 2000s. It then discusses the evolution of ranibizumab and the evidence from clinical trials supporting its use. Finally, it addresses biosimilars that are attempting to enter the anti-VEGF market and highlights some of the differences between biosimilars and innovator biologics.
Curso impartido en SECOIR 2017 por el Dr Alvaro Rodríguez Ratón actualizando las tecnologías de biometría, topografía y tomografía. Incluye IOLmaster, Lenstar, Aladdin, Pentacam, Sirius, Galilei, Argos ...
femtosecond laser in ophthalmology by Dr. Hind Safwat (Al Azhr university) Hind Safwat
Here are the key points about FSL in penetrating keratoplasty:
- FSL allows for precise, consistent cuts that minimize damage to surrounding tissue.
- It can create wound configurations that provide more surface area for healing, improve tissue alignment, require less suture tension, and have superior biomechanical strength.
- Advantages include rapid visual recovery, less astigmatism, and benefits specific to the type of cut (lamellar vs penetrating).
- Contraindications include conditions preventing proper docking of the laser such as severe ocular surface irregularities or recent perforations.
Dry age-related macular degeneration (AMD) is the leading cause of irreversible vision loss among people over 65. It is characterized by the breakdown and loss of cells in the macula due to aging and can be categorized as either dry or wet AMD. Dry AMD accounts for 90% of cases and results in gradual vision loss over time due to buildup of drusen and development of geographic atrophy in the macula. Diagnosis is based on the presence of soft or large drusen, pigmentary abnormalities, and atrophy seen on examination and imaging like OCT. There is no cure for dry AMD and vision loss progresses slowly, resulting in central blind spots.
This document summarizes key information about hard contact lenses, including their advantages, disadvantages, indications for use, and fitting procedures. Hard contact lenses are made of PMMA or similar materials. They are durable, have a long lifespan, provide clear vision, and only require one fitting visit. However, they can be uncomfortable, fall out, break, or warp. Common uses are for astigmatism, aphakia, keratoconus, and during certain medications. The fitting process involves keratometry, trial lenses, adjusting for diameter, base curve, and power. Proper centration, lens movement, and hygiene are important to avoid problems.
Multifocal IOLs provide both near and distance vision without glasses by utilizing concentric zones of different optical powers (refractive MFIOLs) or diffractive properties to split light between two focal points. While eliminating need for glasses, they can cause visual side effects like glare and reduced contrast sensitivity. Careful patient selection and counseling, accurate biometry and surgical technique are important for successful multifocal IOL implantation outcomes.
Optical coherence tomography (OCT) is useful for imaging both the anterior and posterior segments in glaucoma. Posterior segment OCT allows quantification of retinal nerve fiber layer thickness, optic nerve head parameters, and ganglion cell layer thickness. Changes in these measurements over time can help detect glaucomatous progression. Anterior segment OCT visualizes angle anatomy and structures after glaucoma surgery. OCT provides objective data but results must be interpreted carefully while considering limitations such as variability between devices and lack of representation in normative databases.
1) A 76-year-old male presented with decreased vision in the right eye due to neovascular AMD. He underwent 6 injections of ranibizumab in the right eye, which showed a good response.
2) On subsequent follow-up, the left eye developed subretinal fluid and increased PED size, and was treated with ranibizumab injection. A retinal pigment epithelium (RPE) tear developed in the left eye within days of the injection.
3) RPE tears are a known complication of anti-VEGF treatment for neovascular AMD, occurring in 5-19.7% of cases. Taller PED height and greater linear diameter are risk factors
OCT is used to non-invasively image the retina in cross-section with micrometer-level resolution. It works by measuring the interference of light reflected from retinal structures. OCT was developed in 1991 and uses near-infrared light wavelengths of 840nm and 1310nm. OCT provides high-resolution 2D images of the retina and can integrate data points over depth to form 3D representations. It is useful for diagnosing and monitoring many retinal diseases.
National Ocular Biometry Course (NOBC) 2015 An echoslide presentation Anis Suzanna Mohamad
This powerpoint presentation is basically about ocular biometry. Echo presentation is one of the method to deliver infomation that obtain from the course we attend to other staff in our Ophthalmology Department.
This document discusses different types of multifocal intraocular lenses (IOLs) used in cataract surgery. There are three main types: refractive, diffractive, and a combination. Refractive IOLs use concentric rings of different optical powers while diffractive IOLs use diffraction optics to create two focal points. Combination IOLs can provide the advantages of both refractive and diffractive technologies. The document also covers specific multifocal IOL models and considerations for patient selection.
This document provides an overview of the basics of phacoemulsification including machine technology, irrigation and aspiration handpieces, peristaltic pumps, venturi pumps, foot pedal functions, and power variables. Key points include:
- Phacoemulsification uses ultrasonic energy from a piezoelectric crystal to emulsify cataracts.
- Machine technology includes ultrasonic handpieces, irrigation/aspiration tips, and peristaltic or venturi pumps to provide vacuum.
- The foot pedal controls irrigation only, irrigation with aspiration, or full function with ultrasound emission.
- Power is determined by factors like nucleus density, tip engagement, and linear tip velocity to safely sculpt
Objetos De Aprendizaje Nuevo Concepto Instruccionalivylebron
El documento habla sobre los objetos de aprendizaje (OA), definidos como cualquier recurso digital que puede ser reutilizado con fines pedagógicos. Explica sus características, tipos, usos, requisitos y estándares como LOM y SCORM. También describe los repositorios de OA, que permiten almacenar y compartir los OA etiquetados con metadatos para su búsqueda y reutilización. Finalmente, menciona algunos ejemplos de repositorios de OA.
Protection des métaux contre la corrosionCHTAOU Karim
Cette présentation présentent tout d’abord les principaux types de la corrosion et il présente une description détaillée des trois grandes méthodes, préventives et curatives, utilisées en anticorrosion.
Présentation de la plate-forme d'éco-conception CORINEBrice Kosinski
Eurocopter, leader mondial de la filière hélicoptère, a pris l’initiative du projet CORINE pour réduire l’impact environnemental sur la chaîne d’approvisionnement de ses produits civils.
Planifié sur trois ans, CORINE a pour objectif de fournir aux PME un outil d’éco-conception collaboratif entre donneurs d’ordre et fournisseurs. Il permettra d’identifier et d’intégrer de nouveaux matériaux et procédés tout au long du cycle de vie de l’hélicoptère.
CORINE est un outil collaboratif d'éco-conception unique en son genre. Les points clés innovants de l’outil d’éco-conception :
- Interface collaborative entre donneurs d’ordre et fournisseurs permettant de faire des choix en matière d’éco-conception
- Outil simple d’utilisation pour sélectionner les matériaux et procédés améliorant la performance environnementale
- Outil conçu pour la filière aéronautique et adaptable à des secteurs similaires
Rapport de stage : Étudier le principe de fonctionnement des capteurs de régu...Abdo07
Rapport de stage : Étudier le principe de fonctionnement des capteurs de régulation
Réalisé par : AABIDA ABDERRAHIM
Encadré par : BOUCHTA CHRIFI
Durée de stage : Du 1/09/15 au
30/09/15
GROUPE OFFICE CHERIFIEN DES
PHOSPHATES
DIRECTION :
MAROC CHIMIE DE SAFI
La fiche de "conduite à tenir" devant un oedème papillaire et pour d'autre urgences de neuro-ophtalmologie sont disponibles sur le site du CNOF : www.neuro-ophtalmologie-club.org
[DES1 Urgences] Occlusions Vasculaires / Pr M. Paques (17 mars 2012)
[Jeudi de la Retine] Autofluorescence et DMLA atrophique (I. Audo)
1. Autofluorescence du fond d’œil
et
DMLA atrophique(s)
I Audo, M Benchaboune, JF Girmens, S Mohand-Saïd, K Nakashima, M Paques, JA Sahel
2. Qu’est-ce que l’autofluorescence (AF) du fond d’œil?
= visualisation de la LIPOFUSCINE (LF), marqueur fonctionnel du
renouvellement des segments externes des photorécepteurs (=PR/EPR)
Segments externe des photorécepteurs
• AF: reflète l’accumulation de
LF, principalement A2E, dans
les cellules de l’EPR
1 1 1
• Associée au renouvellement
Epithélium
cyclique des segments externes 2 Lipo-
pigmentaire
des photorécepteurs fuscine
rétinien
• = « déchets » de la phagocytose
incomplète, soumis à l ’ auto-
1 Phagocytose
oxydation
2 Autophagie
• Accumulation dans les cellules
post-mitotiques
• Augmente avec l’âge
• Modifiée dans les pathologies
rétiniennes (DMLA, SGDT, Best…)
Delori FC, et al. 2001
http://webeye.ophth.uiowa.edu/DEPT/images/Mullins/index.htm
3. Technique(s) d’imagerie
Non invasive+++
• SLO confocal, type HRA2
Filtre 488 nm
> 521 nm
Autofluorescence (AF)
Laser/488 nm in vivo
Détecteur
Après sommation
Rückmann et al. 1995
• Rétinographe, type Topcon, avec filtres spéciaux
4. Limites de la technique
• Opacité des milieux (cristallin+)
• Absence de quantification absolue => approche plutôt
qualitative
• +/- absence de fixation stable
6. Atrophie géographique
= perte bien délimitée d’autofluorescence + anomalies de
l’autofluorescence dans la zone de jonction
7. Différents aspects d’AF jonctionnelle = différentes DMLA atrophiques
Bindenwald et al., 2005
(FAM study- reading center Bonn)
normal focal patchy banded
DIFFUSE
reticular branching Fine Fine granular with
granular peripheral punctate
spots
8. Différents aspects d’AF jonctionnelle = différentes DMLA
Bindenwald et al., 2005 atrophiques
89,13% même aspect entre les 2 yeux: bonne corrélation intra-individuelle
Facteurs génétiques ?
9. Progression de l’atrophie
vers les zones d’anomalies
d’AF jonctionnelle
FAM study
Holtz et al 2001, 2007
Schmitz-Valckenberg et al 2009
Rythme de progression fonction de la zone jonctionnelle
Moindre progression si pas ou peu de modification d’AF jonctionnelle
≠ modifications diffuses
10. Corrélation
structure/fonction
Fine Matrix Mapping:
baisse de la sensibilité
photopique<scotopique dans la zone de
jonction
Scholl et al., 2004
Micropérimétrie:
Perte de sensibilité dans les cas d’hyper
autofluorescence dans la zone de jonction
Schmitz-Valckenberg et al 2004
11. Corrélation AF/SD-OCT
Hyper AF en bande
OCT: hyper-réflexivité, irrégularité,
épaississement et perte de la LEE
Pas d’hyper AF
OCT: bords abruptes
Conjonction des 2
aspects
Brar et al., 2009
12. Corrélation AF
Kellner et al., 2009
bleue Argon vs proche IR
(Ex 488nm/Em >500nm) (Ex 787nm/Em >800nm) (évite la lumière bleue)
(SE PR/EPR)
Mélanine des mélanosomes, principalement pôle apical EPR
Diminution: blocage ou déplacement des mélanosomes ou
perte cellulaire de l‘EPR
Augmentation: déplacement ou augmentation de la
mélanine, mélanolysosomes, mélanolipofushine
13. = corrélation intéressante
pour le suivi d’essai
thérapeutique
mais
nécessité d’études
longitudinales et meilleures
connaissances de la
pathophysiologie
Kellner et al., 2009
14. Perspectives
• Développement de logiciels pour quantifier la surface d’atrophie et les
anomalies de la zone de jonction
• Approche de quantification des anomalies de l’autofluorescence…
• Poursuite des corrélations avec des techniques d’imagerie haute résolution
pour une meilleure compréhension des anomalies de la zone de jonction et
déterminer les meilleurs indicateurs pronostiques et thérapeutiques