This document discusses ocular biometry and ultrasound. It begins with definitions of biometrics and ultrasound terminology. It then describes the different modes of ultrasound - A-scan, B-scan and M-scan. Key components of ultrasound devices like transducers, amplifiers and velocities of sound through ocular tissues are explained. Factors affecting ultrasound reflection and penetration are outlined. The document concludes with an introduction to ocular biometry procedures and a brief history.
This document discusses peripheral refraction in myopia. It notes that myopia rates have increased significantly worldwide over recent decades. Near work, education level, ethnicity and genetics are identified as risk factors for myopia development. The key structural change associated with myopia is axial elongation of the vitreous chamber. Studies of peripheral refraction show that myopic eyes tend to have relative peripheral hyperopia compared to emmetropic eyes. This peripheral hyperopic defocus in myopic eyes may drive continued axial elongation and myopia progression. New myopia control contact lenses aim to reduce this peripheral hyperopic defocus to slow myopia progression compared to traditional corrective lenses.
This document summarizes various contact lens manufacturing techniques. It discusses soft lens manufacturing methods like moulding, spin casting, and lathing. It describes how these techniques work, their advantages and disadvantages. Rigid gas permeable contact lenses are lathed from cylindrical buttons using back surface and front surface lathes. Additional processes for both soft and rigid lenses include edge polishing, marking, fenestration and final inspection. The document is intended as an overview of contact lens manufacturing processes.
Investigations in a case of corneal ulcer in a clinic setting what to dodrvishuankad
This document discusses investigations for corneal ulcers in a clinic setting. It begins by outlining the importance of microbiological workup for corneal ulcers. The key investigations discussed are smear examination using stains like Gram and KOH to visualize organisms, and culture using media suited to common bacteria, fungi, Acanthamoeba, and other pathogens. Details are provided on collection and handling of corneal scrapings, as well as characteristics and diagnostic features of common organisms causing bacterial, fungal and Acanthamoeba keratitis. The importance of proper sample collection and meticulous laboratory workup is emphasized to arrive at an accurate diagnosis and guide treatment.
different techniques of retinoscopy by which we can find amplitude of accomodation,and correct amount of hyperopia. we can also determine lead and lag of accomodation.
This document summarizes key aspects of perimetry testing. It defines the normal visual field and describes how perimetry can be used to detect functional vision loss and monitor disease progression. Two main types of perimetry are discussed: kinetic and static. Details are provided on testing strategies, stimuli brightness, interpreting results like total deviation and reliability indices. The document emphasizes the importance of perimetry in glaucoma and neurological diagnosis and management.
The Geneva lens measure is an instrument that can measure the curvature, power, and thickness of ophthalmic lenses. It works by having two fixed pins and a movable central pin that indicates the sag of a curved surface when placed on a lens, directly reading the refractive power. It can measure spherical, cylindrical, and bifocal lenses. For materials other than the calibrated refractive index of 1.523, a conversion factor must be applied to calculate the true power. The lens measure is an important tool in optics that has applications beyond just measuring surface power of lenses.
Real active and passive therapy in amblyopia managamentBipin Koirala
This document discusses different therapies for treating amblyopia, including both passive and active approaches. It describes passive therapies like refractive correction, occlusion therapy, and penalization, which aim to eliminate visual deprivation and correct ocular dominance without active effort from the patient. It also discusses active therapies like pleoptics and perceptual learning, which require the patient's conscious involvement in visual tasks to improve performance. The key goals of amblyopia treatment are to restore visual acuity and make the amblyopic eye the preferred eye for fixation and vision.
This document discusses ocular biometry and ultrasound. It begins with definitions of biometrics and ultrasound terminology. It then describes the different modes of ultrasound - A-scan, B-scan and M-scan. Key components of ultrasound devices like transducers, amplifiers and velocities of sound through ocular tissues are explained. Factors affecting ultrasound reflection and penetration are outlined. The document concludes with an introduction to ocular biometry procedures and a brief history.
This document discusses peripheral refraction in myopia. It notes that myopia rates have increased significantly worldwide over recent decades. Near work, education level, ethnicity and genetics are identified as risk factors for myopia development. The key structural change associated with myopia is axial elongation of the vitreous chamber. Studies of peripheral refraction show that myopic eyes tend to have relative peripheral hyperopia compared to emmetropic eyes. This peripheral hyperopic defocus in myopic eyes may drive continued axial elongation and myopia progression. New myopia control contact lenses aim to reduce this peripheral hyperopic defocus to slow myopia progression compared to traditional corrective lenses.
This document summarizes various contact lens manufacturing techniques. It discusses soft lens manufacturing methods like moulding, spin casting, and lathing. It describes how these techniques work, their advantages and disadvantages. Rigid gas permeable contact lenses are lathed from cylindrical buttons using back surface and front surface lathes. Additional processes for both soft and rigid lenses include edge polishing, marking, fenestration and final inspection. The document is intended as an overview of contact lens manufacturing processes.
Investigations in a case of corneal ulcer in a clinic setting what to dodrvishuankad
This document discusses investigations for corneal ulcers in a clinic setting. It begins by outlining the importance of microbiological workup for corneal ulcers. The key investigations discussed are smear examination using stains like Gram and KOH to visualize organisms, and culture using media suited to common bacteria, fungi, Acanthamoeba, and other pathogens. Details are provided on collection and handling of corneal scrapings, as well as characteristics and diagnostic features of common organisms causing bacterial, fungal and Acanthamoeba keratitis. The importance of proper sample collection and meticulous laboratory workup is emphasized to arrive at an accurate diagnosis and guide treatment.
different techniques of retinoscopy by which we can find amplitude of accomodation,and correct amount of hyperopia. we can also determine lead and lag of accomodation.
This document summarizes key aspects of perimetry testing. It defines the normal visual field and describes how perimetry can be used to detect functional vision loss and monitor disease progression. Two main types of perimetry are discussed: kinetic and static. Details are provided on testing strategies, stimuli brightness, interpreting results like total deviation and reliability indices. The document emphasizes the importance of perimetry in glaucoma and neurological diagnosis and management.
The Geneva lens measure is an instrument that can measure the curvature, power, and thickness of ophthalmic lenses. It works by having two fixed pins and a movable central pin that indicates the sag of a curved surface when placed on a lens, directly reading the refractive power. It can measure spherical, cylindrical, and bifocal lenses. For materials other than the calibrated refractive index of 1.523, a conversion factor must be applied to calculate the true power. The lens measure is an important tool in optics that has applications beyond just measuring surface power of lenses.
Real active and passive therapy in amblyopia managamentBipin Koirala
This document discusses different therapies for treating amblyopia, including both passive and active approaches. It describes passive therapies like refractive correction, occlusion therapy, and penalization, which aim to eliminate visual deprivation and correct ocular dominance without active effort from the patient. It also discusses active therapies like pleoptics and perceptual learning, which require the patient's conscious involvement in visual tasks to improve performance. The key goals of amblyopia treatment are to restore visual acuity and make the amblyopic eye the preferred eye for fixation and vision.
This document provides guidance on examining a patient with strabismus. It outlines the goals of assessment as well as techniques for taking a thorough history, measuring eye alignment and movements, assessing binocular vision status, and performing supplementary tests. Key parts of the exam include visual acuity testing, inspection of eye position and movements, motor testing using cover-uncover and prism bar tests, sensory evaluation for diplopia and suppression, and testing for stereopsis. The order of examination and interpretation of test results are also discussed to establish a diagnosis and guide management.
Scleral lens is a large rigid contact lens with a diameter range of 15mm to 25mm. Its resting point is beyond the
corneal borders, and are believed to be among the best vision correction options for irregular corneas. Wearing scleral lens also can postpone or even prevent surgical intervention as well as decrease the risk of corneal scarring.
Keratometry is a technique to measure the curvature of the cornea using a keratometer. A keratometer projects illuminated circles called mires onto the cornea which form reflected images. By measuring the size of the reflected images, the radius of curvature of the cornea can be calculated in two principal meridians. Keratometry is used to measure corneal astigmatism and monitor the shape of the cornea for conditions like keratoconus. Automated keratometers have replaced manual keratometers and can measure corneal curvature more quickly and accurately.
1. The document describes various types of corrective lenses and how their power is measured using trial lenses, a lensometer, or focimeter.
2. A lensometer or focimeter uses targets, power dials, and axis dials to separately measure the sphere, cylinder, and axis of a lens.
3. Key steps involve focusing the instrument, centering the lens, and adjusting dials until target lines are clear, taking note of the power and axis readings.
Esotropia , classification , diagnosis and managementDrAzmat Ali
This document provides information on various types of esotropia (convergent strabismus), including:
- Accommodative esotropia caused by uncorrected hyperopia or a high AC/A ratio
- Partially accommodative esotropia with both accommodative and non-accommodative components
- Non-accommodative esotropia including convergence excess, cyclical esotropia, and acquired forms
- Esotropia associated with high myopia or nystagmus is also discussed
Treatment options including refractive correction, orthoptic exercises, prisms, botulinum toxin, and surgery are mentioned for different types of esotropia.
Ultrasound biomicroscopy (UBM) provides high-resolution imaging of ocular structures in the anterior segment of the eye using 50 MHz ultrasound. UBM allows visualization of tissues like the ciliary body and zonules that are not visible by slit lamp examination. UBM can be used to qualitatively and quantitatively evaluate the anterior segment structures and has applications in diagnosing and monitoring conditions like glaucoma, corneal diseases, tumors, and intraocular lenses. While UBM provides excellent detail, it has limitations including only being able to image about 5mm into the eye and requiring contact with the eye, unlike anterior segment OCT which is non-contact.
Prism is a portion of a refractive medium with two plane surfaces inclined at an angle. It causes light to deviate due to refraction. Prisms are used in ophthalmology to diagnose and manage eye alignment issues like strabismus. Key diagnostic uses include measuring the angle of deviation using prism alternate cover test and investigating binocular single vision through tests like the prism reflex test and prism vergence testing. Prisms are also used therapeutically to correct angles of deviation in conditions like esotropia and exotropia.
The document describes the optical properties of the human eye. It compares the eye to a camera and describes the key optical elements like the cornea, lens, iris, and retina. It discusses the compound optical system of the eye and provides data on refractive indices and radii of curvature from Gullstrand's schematic eye model. It also describes reduced eye models proposed by Listing and Donders that simplify the eye's optics using single refractive surfaces and focal points.
discussion about Aspheric lens, fitting, indication,advantage and Disadvantages with traditional aspheric lens,need of Asphericity,Aspheric Lens Design, identification, troubleshooting
A-scan biometry is an ultrasound test used to measure the length of the eye, which is important for determining treatments for sight disorders. It works by emitting a sound beam into the eye and measuring the echoes that bounce back from different structures. The measurements of axial length, corneal curvature, and estimated lens position are used to calculate the ideal intraocular lens power needed after cataract surgery. Accuracy is important as even small errors in measurement can significantly impact the calculated lens power. Different formulas exist to relate the biometry measurements to the appropriate lens power, with newer regression formulas found to be most accurate.
This document summarizes guidelines for dispensing progressive lenses. It identifies the best candidates as previous progressive lens wearers, emerging presbyopes with low add powers, and highly motivated individuals. It notes that previous bifocal wearers and those with occulomotor imbalances may require consideration. The document outlines the procedure for fitting progressive lenses, which includes selecting a frame, pre-adjusting it, measuring the fitting height and PD, verifying the cut-out, and taking free form measurements. It provides tips for selecting an appropriate frame, including ones that maintain adjustment and avoid large styles that expose the wearer to distortions.
This document discusses hypermetropia (farsightedness), where parallel rays from infinity are focused behind the retina when the eye is at rest. There are several types of hypermetropia based on etiology, including axial (most common, due to short axial length), curvatural (flattened cornea or lens), and index (increased refractive index). Symptoms range from asymptomatic to asthenopia (eye strain) and defective vision. Treatment includes optical correction with glasses or contacts, as well as surgical options like refractive surgery or phakic IOL implantation. Proper visual hygiene from an early age can help prevent complications like amblyopia.
Amblyopia, commonly known as lazy eye, is a condition where vision is reduced in one or both eyes and cannot be corrected by glasses or contact lenses. It is caused by abnormal visual development during childhood. There are several types of amblyopia including stimulus deprivation, strabismic, anisometric, and isometric amblyopia. Treatment involves patching or blurring the stronger eye to encourage use of the weaker eye, along with refractive correction if needed. Therapy is most effective when started early in childhood.
The document discusses different types of lensesometers used to measure the refractive power of lenses. It describes manual lensesometers, which provide accurate power measurements but require skill to use, especially for toric lenses. Automated lensesometers are easier to use and can print prescriptions, but are less accurate than manual models. The document outlines the steps to measure spherical and cylindrical lenses using a manual lensesometer, including focusing the eyepiece, centering the target, and rotating drums to sharpen meridians. Lens power is recorded based on the orientation of central dots or lines in the target.
This document discusses automated perimetry and the interpretation of visual field tests. It covers perimeter logic and identifying field defects, criteria for glaucomatous defects, and detecting glaucomatous progression. Key points include interpreting visual fields systematically using total and pattern deviation plots in 8 zones, criteria for identifying glaucomatous defects including abnormalities in the pattern deviation plot, global indices, and techniques for detecting progression such as the overview program and Glaucoma Progression Analysis. Interpretation requires correlating results with clinical findings and considering factors like learning effects and fluctuation.
The document discusses wavefront aberrometry, which is a technique used to measure aberration in the eye by analyzing wave fronts. It is used for refractive surgery, contact lens fitting, early diagnosis of keratoconus, and to measure lower order and higher order of aberration. Wavefront aberrometry provides information about aberrations in the eye beyond what a standard eye exam can detect.
Retinoscopy is a technique used to objectively measure the refractive error of the eye. Light is directed into the patient's eye to illuminate the retina, and the observer views the resulting reflex to determine the refractive state. There are different types of retinoscopes and techniques used. By observing properties of the fundal reflex such as direction and speed of motion, the observer can determine if the eye is emmetropic, hyperopic, or myopic, and approximately how much refractive error is present. Further testing is done to refine the prescription and determine any astigmatism. Retinoscopy provides an efficient initial objective refraction.
Optics of Retinoscope by Dr. Muhammad Zeeshan Hameed.pptxZeeshan Hameed
Includes
1. What is a Retinoscope?
2. Short History of Retinoscope
3. Parts of a Retinoscope
4. Detailed Optics of a Retinoscope
5. Practical Points of Retinoscopy
This document provides guidance on examining a patient with strabismus. It outlines the goals of assessment as well as techniques for taking a thorough history, measuring eye alignment and movements, assessing binocular vision status, and performing supplementary tests. Key parts of the exam include visual acuity testing, inspection of eye position and movements, motor testing using cover-uncover and prism bar tests, sensory evaluation for diplopia and suppression, and testing for stereopsis. The order of examination and interpretation of test results are also discussed to establish a diagnosis and guide management.
Scleral lens is a large rigid contact lens with a diameter range of 15mm to 25mm. Its resting point is beyond the
corneal borders, and are believed to be among the best vision correction options for irregular corneas. Wearing scleral lens also can postpone or even prevent surgical intervention as well as decrease the risk of corneal scarring.
Keratometry is a technique to measure the curvature of the cornea using a keratometer. A keratometer projects illuminated circles called mires onto the cornea which form reflected images. By measuring the size of the reflected images, the radius of curvature of the cornea can be calculated in two principal meridians. Keratometry is used to measure corneal astigmatism and monitor the shape of the cornea for conditions like keratoconus. Automated keratometers have replaced manual keratometers and can measure corneal curvature more quickly and accurately.
1. The document describes various types of corrective lenses and how their power is measured using trial lenses, a lensometer, or focimeter.
2. A lensometer or focimeter uses targets, power dials, and axis dials to separately measure the sphere, cylinder, and axis of a lens.
3. Key steps involve focusing the instrument, centering the lens, and adjusting dials until target lines are clear, taking note of the power and axis readings.
Esotropia , classification , diagnosis and managementDrAzmat Ali
This document provides information on various types of esotropia (convergent strabismus), including:
- Accommodative esotropia caused by uncorrected hyperopia or a high AC/A ratio
- Partially accommodative esotropia with both accommodative and non-accommodative components
- Non-accommodative esotropia including convergence excess, cyclical esotropia, and acquired forms
- Esotropia associated with high myopia or nystagmus is also discussed
Treatment options including refractive correction, orthoptic exercises, prisms, botulinum toxin, and surgery are mentioned for different types of esotropia.
Ultrasound biomicroscopy (UBM) provides high-resolution imaging of ocular structures in the anterior segment of the eye using 50 MHz ultrasound. UBM allows visualization of tissues like the ciliary body and zonules that are not visible by slit lamp examination. UBM can be used to qualitatively and quantitatively evaluate the anterior segment structures and has applications in diagnosing and monitoring conditions like glaucoma, corneal diseases, tumors, and intraocular lenses. While UBM provides excellent detail, it has limitations including only being able to image about 5mm into the eye and requiring contact with the eye, unlike anterior segment OCT which is non-contact.
Prism is a portion of a refractive medium with two plane surfaces inclined at an angle. It causes light to deviate due to refraction. Prisms are used in ophthalmology to diagnose and manage eye alignment issues like strabismus. Key diagnostic uses include measuring the angle of deviation using prism alternate cover test and investigating binocular single vision through tests like the prism reflex test and prism vergence testing. Prisms are also used therapeutically to correct angles of deviation in conditions like esotropia and exotropia.
The document describes the optical properties of the human eye. It compares the eye to a camera and describes the key optical elements like the cornea, lens, iris, and retina. It discusses the compound optical system of the eye and provides data on refractive indices and radii of curvature from Gullstrand's schematic eye model. It also describes reduced eye models proposed by Listing and Donders that simplify the eye's optics using single refractive surfaces and focal points.
discussion about Aspheric lens, fitting, indication,advantage and Disadvantages with traditional aspheric lens,need of Asphericity,Aspheric Lens Design, identification, troubleshooting
A-scan biometry is an ultrasound test used to measure the length of the eye, which is important for determining treatments for sight disorders. It works by emitting a sound beam into the eye and measuring the echoes that bounce back from different structures. The measurements of axial length, corneal curvature, and estimated lens position are used to calculate the ideal intraocular lens power needed after cataract surgery. Accuracy is important as even small errors in measurement can significantly impact the calculated lens power. Different formulas exist to relate the biometry measurements to the appropriate lens power, with newer regression formulas found to be most accurate.
This document summarizes guidelines for dispensing progressive lenses. It identifies the best candidates as previous progressive lens wearers, emerging presbyopes with low add powers, and highly motivated individuals. It notes that previous bifocal wearers and those with occulomotor imbalances may require consideration. The document outlines the procedure for fitting progressive lenses, which includes selecting a frame, pre-adjusting it, measuring the fitting height and PD, verifying the cut-out, and taking free form measurements. It provides tips for selecting an appropriate frame, including ones that maintain adjustment and avoid large styles that expose the wearer to distortions.
This document discusses hypermetropia (farsightedness), where parallel rays from infinity are focused behind the retina when the eye is at rest. There are several types of hypermetropia based on etiology, including axial (most common, due to short axial length), curvatural (flattened cornea or lens), and index (increased refractive index). Symptoms range from asymptomatic to asthenopia (eye strain) and defective vision. Treatment includes optical correction with glasses or contacts, as well as surgical options like refractive surgery or phakic IOL implantation. Proper visual hygiene from an early age can help prevent complications like amblyopia.
Amblyopia, commonly known as lazy eye, is a condition where vision is reduced in one or both eyes and cannot be corrected by glasses or contact lenses. It is caused by abnormal visual development during childhood. There are several types of amblyopia including stimulus deprivation, strabismic, anisometric, and isometric amblyopia. Treatment involves patching or blurring the stronger eye to encourage use of the weaker eye, along with refractive correction if needed. Therapy is most effective when started early in childhood.
The document discusses different types of lensesometers used to measure the refractive power of lenses. It describes manual lensesometers, which provide accurate power measurements but require skill to use, especially for toric lenses. Automated lensesometers are easier to use and can print prescriptions, but are less accurate than manual models. The document outlines the steps to measure spherical and cylindrical lenses using a manual lensesometer, including focusing the eyepiece, centering the target, and rotating drums to sharpen meridians. Lens power is recorded based on the orientation of central dots or lines in the target.
This document discusses automated perimetry and the interpretation of visual field tests. It covers perimeter logic and identifying field defects, criteria for glaucomatous defects, and detecting glaucomatous progression. Key points include interpreting visual fields systematically using total and pattern deviation plots in 8 zones, criteria for identifying glaucomatous defects including abnormalities in the pattern deviation plot, global indices, and techniques for detecting progression such as the overview program and Glaucoma Progression Analysis. Interpretation requires correlating results with clinical findings and considering factors like learning effects and fluctuation.
The document discusses wavefront aberrometry, which is a technique used to measure aberration in the eye by analyzing wave fronts. It is used for refractive surgery, contact lens fitting, early diagnosis of keratoconus, and to measure lower order and higher order of aberration. Wavefront aberrometry provides information about aberrations in the eye beyond what a standard eye exam can detect.
Retinoscopy is a technique used to objectively measure the refractive error of the eye. Light is directed into the patient's eye to illuminate the retina, and the observer views the resulting reflex to determine the refractive state. There are different types of retinoscopes and techniques used. By observing properties of the fundal reflex such as direction and speed of motion, the observer can determine if the eye is emmetropic, hyperopic, or myopic, and approximately how much refractive error is present. Further testing is done to refine the prescription and determine any astigmatism. Retinoscopy provides an efficient initial objective refraction.
Optics of Retinoscope by Dr. Muhammad Zeeshan Hameed.pptxZeeshan Hameed
Includes
1. What is a Retinoscope?
2. Short History of Retinoscope
3. Parts of a Retinoscope
4. Detailed Optics of a Retinoscope
5. Practical Points of Retinoscopy
2. Geschichte:
• Sir William Bowman (1859 – Großbritanien) : hat durch Drehen
seines Ophthalmoskopspiegels leichte Grade von Keratokonus bei
Beobachtung von Schattenbewegungen erkannt.
• Ferdinand Cuignet (1823-1890 / Frankreich) : Er beschrieb die
Schatten, bei Drehung seines Ophthalmoskopspiegels, und
verwendet den Begriff „Keratoskopie“ dafür.
3. Ein erst bekanntes elektrisches selbstleuchtendes Skiaskop war von
De Zeng (1915).
4. Jack Copeland 1927-USA: das erste
Streifenskiaskop, was die Beobachtung von
Astigmatismus erleichterte.
Andrew Jay Cross (1855-1925/ USA): Einführung
der dynamischen Skiaskopie zur Messung der
Akkomodation, genannt als „dynamische
Skiametrie“ hat Astigmatismus und Scissor´s
Reflex vor Copeland ohne Streifenskiaskop
feststellen können.
„You can´t learn Retinoscopy by
reading a book“ Copeland.
Optomitristen
5. Grundlagen
• Brechung ist die Konvergenz eines Lichtstrahls, wenn er von einem Medium zu
einem anderen Medium mit unterschiedlicher optischer Dichte (Brechungsindex)
übergeht.
• Das Auge mit normalem optischen Zustand ist Emmetropie und das mit Anomalie
ist Ametropie (mit Brechungsfehler).
• Bei Emmetropie werden parallele Strahlen aus der Ferne auf die Netzhaut
fokussiert (bei Ruhe, ohne Akkommodation). Dies ergibt ein klares, ausreichend
großes Bild.
• Bei Fehlsichtigkeit werden parallele Strahlen aus der Ferne nicht auf die Netzhaut
fokussiert. Auf der Netzhaut dieses Auges entsteht also kein klares Bild des
Objekts.
6.
7. Nutzen
• Bestimmung der Refraktion des Auges auf der Grundlage der optischen
Prinzipien der Refraktion.
• Möglicherweise die einzige Möglichkeit zur Bestimmung der Fehlsichtigkeit
bei nicht kommunikativen oder nicht kooperativen Patienten –
Säuglingen/Kindern – Sprachbarriere – Lernschwierigkeiten – Simulanten –
kognitive Sehbehinderungen.
• Bestimmung der Refraktion bei irregulärem Astigmatismus.
• Screening für Augenerkrankungen : Keratokonus, Medientrübungen.
8. Sorten
• Statische Skiaskopie: Zur Bestimmung des Brechungszustands durch
Fixierung des Patienten in der Ferne (Ruhezustand – keine
Akkomodation).
• Dynamische Skiaskopie: - Um den Refraktionszustand zu bestimmen,
indem der Patient in der Nähe fixiert (aktive Akkomodation).
9. • Prinzip: Das Verhalten des Lichtreflexes in der Pupille, wenn die
Beleuchtung über den Augenhintergrund bewegt wird. Es hängt von der
Neigung der Lichtstrahlen ab, die aus der Pupille kommen. Es hängt auch
von der Position des Untersuchers ab. (Standardabstand in statischer
Skiaskopie : Armlänge vom Untersucher)
10. Der Spiegel
funktioniert wie
ein
Konkavspiegel
mit Konvergenz:
Sleeve up
Non Copeland
Mitlauf –
Gegenlauf +
Der Spiegel
funktioniert
wie ein flacher
spiegel:
Sleeve down
in Non
Copeland
Skiaskop
Mitlauf +
Gegenlauf -
Sleeve
Beobachterseite
11. Das Vorgehen (statisch):
• Das nicht untersuchte Auge mit +2.0 Dpt. vernebeln zur Entspannung der
Akkomodation (falls keine Zykloplegie gewünscht bzw. „Dry Skiaskopie“.
• Bei V.a. Amblyopie das andere Auge abdecken.
• Der Patient sitzt im etwas dunklen Zimmer, eine Armlänge vom
Untersucher entfernt, der Patient soll auf die Ferne fokusieren.
• Der Untersucher sitzt vorm Patienten auf der gleichen Ebene und versucht
nicht im Weg zu stehen beim Skiaskopieren.
• Schwankendes Leuchten der Pupille mit „Sleeve voll nach unten“ von nasal
nach temporal und umgekehrt dann von superior nach inferior.
• Erreichen des Endpunktes bei Neutralisation des Lichtreflexes.
13. Der Endpunkt der Neutralisation:
• Intensität : Bei hohen Brechungsfehlern sehen wir einen schwachen Reflex
und bei niedrigen Brechungsfehlern einen helleren Reflex.
• Geschwindigkeit: Bei starker Ametropie sehen wir eine langsame
Bewegung, bei geringer Ametropie eine schnelle Bewegung des Reflexes.
Ebenso wenn der neutrale Punkt erreicht ist, ist die Bewegung des Reflexes
schneller.
• Reflexbreite: Bei hoher Ametropie sehen wir einen schmalen Reflex. Reflex
wird breiter bis maximal groß, wenn der neutrale Punkt erreicht ist.
14. • Notizen:
• Nach Erreichen des neutralen Punktes (Endpunkt) in der Skiaskopie mit
Planspiegel, ergibt die leichte Bewegung näher zum Patienten eine „mit
Bewegung“ (weil der Fernpunkt jetzt hinter dem Beobachter liegt).
• Wenn Sie sich leicht vom Patienten entfernen, erhalten Sie eine „Gegenbewegung“
(da sich der Fernpunkt jetzt zwischen dem Beobachter und dem Patienten
befindet).
• Bei Medientrübungen und Narben den helleren Reflex neutralisieren, rund um die
Narbe herum spiegeln, aber versuchen trotzdem in die Sehachse zu leuchten.
• Bei Brillenbestimmung nicht vergessen den Effekt vom Abstand zum Skiaskop vom
Endresultat zu subtrahieren (Working Distance) -1.50 Dpt
15. Scissoring-Reflex:
Hilft bei der Diagnose eines irregulären
Astigmatismus (zB. Keratoconus).
Kann nicht vollständig neutralisiert werden (da
mehrere Lichtreflexen vorhanden sind). Die
Haupachse kann ggf. anhand der Topographie
oder Pentacam identifiziert werden.
16. Indikation der Zykloplegie: „wet“
• Kinder (<3 Jahre alt definitiv).
• Verdacht auf latente Hyperopie, Zilarspasmus (Pseudomyopie).
• Akkomodative Esotropie, Strabismus im Kindesalter.
• Nicht kooperative Patienten.
• Variabler und inkonsistenter Endpunkt der Refraktion.
• Die Sehschärfe wird nicht auf das vorhergesagte Niveau korrigiert.
• Erste Brillenanpassung.
• Verdacht auf Amblyopie.
17. • Bei Verwendung von Atropin
wird bei der Endkorrektur 1 Dpt
abgezogen.
• Bei Verwendung anderer
Zykloplegika werden 0,5 Dpt als
Endkorrektur abgezogen.
18. Befunddokumentation:
Optical cross:
Angenommen, der erste zu neutralisierende Meridian
liegt bei 90 Grad. Dies bedeutet, dass Ihr Streifen auf 180
ausgerichtet ist und Sie den Streifen entlang des 90-
Grad-Meridians bewegen. Angenommen, es wird mit
einer -4,50 Dpt neutralisiert.
• Jetzt beleuchten Sie den 180-Grad-Meridian und es
wird mit -3,00 Dpt. neutralisiert.
Deine Notizen lauten wie folgt:
• -4,50 bei 90° -3,00 bei 180°
19. Das Brillenrezept:
• Wir beginnen mit dem vertikalen Meridian und schreiben -4,50 als unsere
Sphärenstärke auf. Auf dem Zahlenstrahl bewegen wir uns von -4,50 bis -3,00, das
ist eine Strecke von +1,50, die wir als unseren Zylinderwert aufschreiben. Die
Achse ist die gleiche wie der Meridian, der unserer anfänglichen Sphärenstärke
entspricht, die in diesem Fall 90 beträgt. Das führt zu:
• -4,50 +1,50 x 90° oder bei Transposition : -3,00 -1,50 x 180°
• Sie müssen noch den Arbeitsabstand von der Sphärenstärke abziehen (1,50 Dpt.)
dann, lautet Ihr Retinoskopie-Ergebnis:
• -6,00 +150 x 90° oder -4,50 - 1,50 x 180°
21. MEM (Monocular Estimate Method)
• Der Test wird bei normaler Raumbeleuchtung durchgeführt.
• Der Patient trägt seine Korrektur und schaut mit beiden Augen gleichzeitig.
• Der Untersucher sitzt etwas unterhalb der Augenhöhe des Patienten, sodass das
Auge des Patienten beim Blick auf das Ziel leicht nach unten gerichtet ist, wie dies
beim Lesen der Fall wäre.
• Wir neutralisieren den Pupillenreflex, während sich der Patient ein nahes Ziel
anschaut (normalerweise 40 cm).
• Mitlauf = Verzögerung der Akk. PLUS addieren.
• Gegenlauf = Führung von der Akk. Minus addieren.
22. Nott Methode (Ivan Nott (1892-1969) Kanada)
• Der Patient fixiert auf ein stabiles Objekt in der Nähe.
• Ein Adäquater Abstand für die Karte ist 40 cm.
• Der Arzt bewegt sich auf den Patienten zu und von ihm weg, bis
Neutralität sichtbar ist.
• Gegenlauf dann Bewegung des Skiaskops näher zum Patienten.
• Mitlauf Bewegung des Skiaskops weg vom Patienten.
• Normbefund = 0,25 bis 0,75 Dpt bds gleich.
Neutralität bei 40 cm Akk. beträgt 2.5 Dpt
Neutralität bei 50 cm Akk. beträgt 2.0 Dpt Differenz vom Norm ist die akk.
Verzögerung, hier 0,5 Dpt
23.
24. Befundanalyse:
• Nicht-Presbyopie: Verzögerung von +0,50 Dpt bis +0,75 Dpt beim Test bei 40 cm.
• Presbyope: Akkommodationsfähigkeit nimmt ab, zunehmende erwartete
Verzögerung der Akkommodation.
• Absolute Presbyopen: Die erwartete Verzögerung beträgt +2,50 Dpt bei 40 cm.
• Akk. Verzögerung > +0,75Dpt : (Verursacht durch akkommodative Dysfunktion)
Insuffizienz, Müdigkeit, Parese, Unfähigkeit. Möglicherweise auch unkorregierte
Hyperopie, Überminus Korrektur.
• Fehlerursachen: Müdigkeit, incompliance bei Fixation, Medientrübungen, enge
Pupille.
25. Zum Weiterlernen…
Dynamische Skiaskopie (Journal of Behavioral Optometry-Englisch)
https://www.oepf.org/wp-content/uploads/2021/08/21-
320Koslowe1.pdf
Retinoscopy simulator
• https://aao-resources-
enformehosting.s3.amazonaws.com/resources/Pediatrics_Center/Ret
inoscopy-Simulator/ret.html