Contact lenses and low vision aids can help improve vision. Contact lenses come in hard and soft materials and can correct refractive errors. Low vision aids like convex lenses and Galilean systems magnify objects to increase the retinal image size and improve vision. Common problems with contact lenses include improper fit and complications like infections. Low vision aids are limited by small fields of view and reduced depth of field at high magnifications.
Presbyopia/ Methods of Presbyopic Addition Determination (healthkura.com)Bikash Sapkota
DIRECT DOWNLOAD LINK ❤❤https://healthkura.com/presbyopia-near-addition/❤❤
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Presbyopia and techniques of measurement
A fantastic presentation in the topic "Presbyopia and techniques of measurement"
A detailed information about presbyopia, techniques of presbyopic add determination and different correction methods.
Informative slide presentation on presbyopia for ophthalmology residents, ophthalmologists, optometrists, ophthalmic assistants, ophthalmic technicians, ophthalmic nurses, medical students, medical professors, teaching guides.
Presentation Contents:
--Introduction to presbyopia
-Types of presbyopia
-Risk factors
-Symptoms and signs
-Refractive error and presbyopia
-Methods of determining near add.
-Management of presbyopia
In a nutshell..
- The evaluation and management of presbyopia are important because significant functional deficits can occur when the condition is left untreated
- Undercorrected or uncorrected presbyopia can cause significant visual disability and have a negative impact on the pt.'s quality of life
- Finally, every tentative addition should be adjusted according to the particular needs of the patient
For Further Reading:
-Clinical Procedures in Optometry by J.D. Bartlett, J.B. Eskridge, J.F. Amos
-Primary Care Optometry by Theodere Grosvenor
-Borish’s Clinical Refraction by W.J. Benjamin
-Clinical Procedures for Ocular examination by Carlson et al
-American Academy of Ophthalmology
-Optometric Clinical Practice Guideline by American Optometric Association
-Internet
Follow me to get in touch with optometric and ophthalmic updates.
Presbyopia/ Methods of Presbyopic Addition Determination (healthkura.com)Bikash Sapkota
DIRECT DOWNLOAD LINK ❤❤https://healthkura.com/presbyopia-near-addition/❤❤
Dear viewers Check Out my other piece of works at ❤❤❤ https://healthkura.com ❤❤❤
Presbyopia and techniques of measurement
A fantastic presentation in the topic "Presbyopia and techniques of measurement"
A detailed information about presbyopia, techniques of presbyopic add determination and different correction methods.
Informative slide presentation on presbyopia for ophthalmology residents, ophthalmologists, optometrists, ophthalmic assistants, ophthalmic technicians, ophthalmic nurses, medical students, medical professors, teaching guides.
Presentation Contents:
--Introduction to presbyopia
-Types of presbyopia
-Risk factors
-Symptoms and signs
-Refractive error and presbyopia
-Methods of determining near add.
-Management of presbyopia
In a nutshell..
- The evaluation and management of presbyopia are important because significant functional deficits can occur when the condition is left untreated
- Undercorrected or uncorrected presbyopia can cause significant visual disability and have a negative impact on the pt.'s quality of life
- Finally, every tentative addition should be adjusted according to the particular needs of the patient
For Further Reading:
-Clinical Procedures in Optometry by J.D. Bartlett, J.B. Eskridge, J.F. Amos
-Primary Care Optometry by Theodere Grosvenor
-Borish’s Clinical Refraction by W.J. Benjamin
-Clinical Procedures for Ocular examination by Carlson et al
-American Academy of Ophthalmology
-Optometric Clinical Practice Guideline by American Optometric Association
-Internet
Follow me to get in touch with optometric and ophthalmic updates.
A lecture on the current techniques (mainly surgical) for the correction of Presbyopia. This includes information on static and dynamic surgical and non surgical approaches.
Various laser lenses have been introduced following Goldmann 3- mirror and Goldmann fundus contact lens for retinal photocoagulation.
Below described some of the time-tested lenses in widespread use. Precise knowledge of these lenses is necessary for safe retinal photocoagulation.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Here is the updated list of Top Best Ayurvedic medicine for Gas and Indigestion and those are Gas-O-Go Syp for Dyspepsia | Lavizyme Syrup for Acidity | Yumzyme Hepatoprotective Capsules etc
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Basavarajeeyam is an important text for ayurvedic physician belonging to andhra pradehs. It is a popular compendium in various parts of our country as well as in andhra pradesh. The content of the text was presented in sanskrit and telugu language (Bilingual). One of the most famous book in ayurvedic pharmaceutics and therapeutics. This book contains 25 chapters called as prakaranas. Many rasaoushadis were explained, pioneer of dhatu druti, nadi pareeksha, mutra pareeksha etc. Belongs to the period of 15-16 century. New diseases like upadamsha, phiranga rogas are explained.
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
4. Contact Lenses
• Contact lenses are lenses/
ocular prosthetic devices
that are placed directly on
the surface of the eyes.
• They are used for a variety
of reasons – therapeutic,
cosmetic, diagnostic.
5. History of CLs
1880s- Scleral lenses
1940s – development of
PMMA (Hard lenses)
1970s – development of
HEMA (Soft lenses)
1980s – development of
RGP lenses (gas
permeable)
1990s – development of
silicone hydrogel lenses
6. Contact Lens materials
Can be classified as hard
or soft based on rigidity.
Can be classified as
hydrophilic or hydrophobic
based on interaction with
water.
Can be classified by
modality – daily wear,
extended wear and
continuous wear
8. PMMA
(Polymethylmethacrylate)
Organic plastic
compounds but hard as
glass
Refractive Index: 1.48 -
1.50
Pros: good clarity,
durability, lack of toxicity
Cons: lack of oxygen
permeability can leads to
corneal hypoxia and
limbal neovasularization.
9. Cellulose Acetate Butyrate
Used to make Rigid Gas
Permeable (RGP)
lenses.
Pros: Slightly better
oxygen permeability,
strong and durable
Con: Prone to warpage
(temporary change in
corneal curvature not
associated with corneal
edema. Regress after
CL is removed)
14. Base Curve
Base
Curve/Posterior
Central Curvature:
curvature of central
posterior surface of
the lens adjacent to
cornea. Measured in
mm (radius) or
dioptric power
(reciprocal of radius)
in air.
15. Diameter
Diameter: Width of
contact lens, typically
varies with lens
material (SCL - 13mm
to 15mm, HCL -9mm to
10mm).
Scleral CLs have a
diameter of around
25mm.
16. Power
Power: dioptric power of
the contact lens similar
to posterior vertex
power of spectacle lens
calculated by Snell’s law
D=[n2-n1]/r
n1= Refractive Index in
air, n2= Refractive Index
CL constant
r= radius of curvature of
CL
17. Optic Zone
Optic Zone – Area of
front surface of contact
lens that is main
contributor to refractive
power of the contact
lens
18. Peripheral curves
Peripheral curves:
Secodary curves just
outside the base curve
at the edge of the lens.
Typically flatter than the
base curve with edges
smoothed out/blended to
increase comfort and
reduce aberrations.
19. Tear Lens
Tear Lens – Optical
lens formed by the
tear film layer
between posterior
surface of a contact
lens and anterior
surface of cornea.
20. Tear Lens
Soft CLs are flexible and conform
to shape of cornea so tear lens in
Soft CLs have identical front and
back surfaces making it’s power
plano.
In Rigid CLs, tear lens can have
different anterior and posterior
surfaces thus inducing an inherent
power of their own which is then
added to the optical system of the
eye.
21. Tear Lens
Steeper than K – plus power
On K – no power
Flatter than K – minus power
24. Field of view
Contact lenses provide a larger field of view than spectacle
lenses.
CLs move with the eye and ensure good vision in all gaze
positions.
Much of peripheral distortion such as spherical abberations
are avoided by CLs.
25. Image size/ Anisometropia
Recall - Relative Spectacle Magnification - change
in retinal image size with optical correction.
In axial myopes, correcting lens closer to anterior
focal point produces a magnified image
Because CLs have a shorter vertex distance image
size changes are less pronounced with CLs as
compared to spectacles.
CLs produce a magnified image in axial myopes.
In refractive ametropia image size approaches
emmetropic image size as lens is moved nearer
than anterior focal point.
26. Aniseikonia
Aniseikonia- difference in retinal image size due to unequal
magnification
Can be due to retinal pathology or anisometropia (e.g in
unilateral aphakic patient)
Aniseikonia is reduced with CLs as they become itegral part of
optical system of the eye.
Hence CLs can improve binocular vision in some cases.
Uncorrected Corrected with Spectacles CLs
27. Convergence
Spectacle lenses centered for
distance induce a prismatic effect
when eyes converge for near
vision.
Hyperopic specatcle correction
increases convergence demand
while myopic spectacle correction
increases convergences demand.
This is because as eyes
converge, the spectacles don’t.
CLs remain centered at all gazes
hence they reduce this effect.
CLs decrease convergence
demand in hypermetropic eye
and increase convergence
demand in myopic eye.
A- convergence demand
increases in hyperope
spectacles
B- convergence demand
decreased in myopic
28. Accomodation
Myopic spectacles have a
base-in prismatic effect
that reduces the amount
of convergence and
accomodation.
Using CLs therefore
demands greater
convergence and
accomodation.
29. Accomodation
Compared with spectacle lenses:
1. CLs increase the accomodative requirements of
myopic eye and decrease
2. CLs decrease accomodative requirements of
hypermetropic eye.
This is because CLs eliminate accomodative advantage
of myopia correcting spectacles and accomodative
disadvantage of hypermetropia correcting spectacles.
30. Prisms
It is possible to incorporate upto 3 dioptres of prism
power to a corneal CL and upto 6 dioptres of prism
power in a scleral lens.
Prism is always base down because it’s weight can
rotate CL.
Horizontal prismatic correction is not possible with
corneal CLs.
31. Optical Aberrations
Prismatic aberrations reduced by CLs as described earlier.
Oblique aberrations occuring when looking through non-
axial portion of lens is also minimized by CLs.
32. Keratoconus
Certain cases of
Keratoconus may also
benefit from contact lens
use.
Usually only rigid contact
lenses allow good vision
in such cases.
If cornea is too steep or
scarred CLs may not be
appropriate.
33. Multifocal CL
Presbyopic, aphakic and pseudophakic patients need to
achieve optical correction for more than 1 distance as
their accomodation is reduced or absent.
Different CLs can be prescribed to these patients as an
alternative.
One of these options is monovision which means fitting
one eye with a lens for distance correction and fellow eye
with a lens for near correction. In such cases, patients
must learn to adapt to concentrating on clearer image
from one eye.
34. Multifocal CL
Multifocal and Bifocal
CLs have different
designs e.g annular
where central zone
corrects for distance and
surrouding annular
zones correct for near.
35. Multifocal CL
For concentric/Annular CLs, patient must adapt to
concentrate on viewing through certain part of the CL to
form a clear image on the retina.
For aspheric CLs the central part of the CL corrects for
distance and there is a gradual transition in power at the
periphery which corrects for near.
For segmental bifocal CLs, the near addition is incorporated
in the lower portion of the lens. The eye looks through the
distance portion when in primary position.
Diffractive bifocal lenses have concentric diffraction rings on
their posterior surface which focus equally on distance and
near objects.
36. Problems with CL useage
Ill fitting CL – if
posterior surfce of CL
is flat it will move
excessively on cornea
and cross visual axis
CL power is affected
by evaporation of
water, temperature,
dryness of
atmosphere.
Corneal Warpage
Mechanical, hypoxic,
immmune response
and suppurative
keratitis
38. Low Vision Aids - Intro
An optical or non-optical device that
immproves or enhances residual vision by
magnifying image of object at retinal level.
Magnifying devices of several kinds are used
to assist poorly sighted patients in daily life.
Most of LVAs are designed to help with
reading.
However some LVAs help with distance vision
as well e.g watching TV, bus numbers etc
39.
40. Low Vision Aids - Intro
Most LVAs present the patient with
a magnified view of object by
increasing angle subtended by the
object at eye.
Recall – angular magnification is
governed by the angle subtended at
the eye. If the angle stays constant
the apparent size of image of
objects at A, B, C or D remains
42. Convex Lenses
A convex lens (32D)
may be used as a
magnifying loupe.
Object is brought within
the focal length of the
convex lens and an
erect, virtual and
magnified image is
formed.
High powered convex
lenses mounted in
spectacles work
similarly.
Power of such lens is
43. Convex Lenses
Convex lens may also
be used as hand held
magnifiers or mounted
on legs as stand
magifiers.
Paperweight magnifiers
rest on page and use a
thick plano convex lens.
Bar shaped cylindrical
convex lenses may also
be used for reading.
44. Convex Lenses
Object is located between
first principal focus and the
lens.
As the object moves closer
to the lens the virtual
image enlarges.
Hence the hand held
magnifier can be
positioned at an
appropriate distance by the
patient.
Field of vision – increases
with size of lens,
decreased with eye-lens
distance.
45. Galilean System
Galiliean telescope
is an optical system
that produces an
erect magnified
image.
Composed of a
convex objective
and concave
eyepiece lens
separated by
46. Galilean System
Works by increasing the
angle subtended by the
object at the eye.
Fe- Power of eye piece lens in dioptres
Fo – Power of objective lens in dioptres
47. Galilean System
Pros:
1. Good enhancement of
distant vision
Cons:
1. Restricted Field of view
2. Depth Perception distorted
3. Expensive
51. Limitations of LVAs
High magnification results in decreased field of view –
makes rapid scanning difficult
Object has to be held close to eye
Depth of field reduced