These lectures has prepared for postgraduate student (Ophthalmology) according to the curriculum of Bangladesh College of Physician and Surgeons (BCPS) and Bangabondhu Sheikh Mujib Medical University (BSMMU) Bangladesh
Presentation containing information about all types of absorptive lenses its manufacturing, uses, advantages and disadvantages and some information about lens coatings.
progressive addition lenses , needs of PAL, permanent and temporary marking of PAL, parts of PAL, design of PAL, Progressive corridor and their importance ,theory behind the PAL,Sand box analogy,OPTICAL DESCRIPTION OF PROGRESSIVELENSES,patterns of PAL,Advantage and Limitation of PAL,fitting of PAL and Frame selection for PAL,measurements for fitting,verification of PALs,
traubleshooting in PALs,Brands and special design of PALs
Presentation containing information about all types of absorptive lenses its manufacturing, uses, advantages and disadvantages and some information about lens coatings.
progressive addition lenses , needs of PAL, permanent and temporary marking of PAL, parts of PAL, design of PAL, Progressive corridor and their importance ,theory behind the PAL,Sand box analogy,OPTICAL DESCRIPTION OF PROGRESSIVELENSES,patterns of PAL,Advantage and Limitation of PAL,fitting of PAL and Frame selection for PAL,measurements for fitting,verification of PALs,
traubleshooting in PALs,Brands and special design of PALs
Ophthalmic Prisms: Prismatic Effects and DecentrationRabindraAdhikary
Ophthalmic Prisms: Prismatic Effects and Decentration
here we discuss about the ophthalmic prisms, the prismatic effects as caused by the decentration( moving the optical center away from the visual axis)
This lecture is based on medical students those are preparing for postgraduate degree namely FCPS/MS/MD/ any any subject coz hypertension is a systemic disease and by seeing the ocular fundus we can asses the general condition of blood vessels in major organ.
This lecture is based on post-graduate students of Ophthalmology (DO, DCO, MCPS, FCPS, MS) and optical principle of LASER, construction of laser and laser tissue interaction has cover the lecture
This lecture is based on post-graduate students of Ophthalmology (DO, DCO, MCPS, FCPS, MS) and optical principle of GAT has to know for a student to use the instrument friendly
This lecture is based on post-graduate medical students of all subject those who are students MS/MD/FCPS of different subject on Central Tendency and Dispersion.
This is the 5 th lecture on "Research Methodology through zoom. The lecture was based on postgraduate Medical students those are different courses of FCPS/MS/MD/PhD (any Specialty)
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
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Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
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2 Case Reports of Gastric Ultrasound
CDSCO and Phamacovigilance {Regulatory body in India}NEHA GUPTA
The Central Drugs Standard Control Organization (CDSCO) is India's national regulatory body for pharmaceuticals and medical devices. Operating under the Directorate General of Health Services, Ministry of Health & Family Welfare, Government of India, the CDSCO is responsible for approving new drugs, conducting clinical trials, setting standards for drugs, controlling the quality of imported drugs, and coordinating the activities of State Drug Control Organizations by providing expert advice.
Pharmacovigilance, on the other hand, is the science and activities related to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems. The primary aim of pharmacovigilance is to ensure the safety and efficacy of medicines, thereby protecting public health.
In India, pharmacovigilance activities are monitored by the Pharmacovigilance Programme of India (PvPI), which works closely with CDSCO to collect, analyze, and act upon data regarding adverse drug reactions (ADRs). Together, they play a critical role in ensuring that the benefits of drugs outweigh their risks, maintaining high standards of patient safety, and promoting the rational use of medicines.
2. • A prism is defined
as a portion of a
refracting medium
bordered by two
plane surfaces
which are inclined
at a finite angle.
3. Axis of the prism: A line bisecting the angle
Apex: The thin edge where the intersecting
surfaces meet
Base: The opposite surface.
Refracting/ Apical angle
of the prism: The angle
between the two surfaces
4.
5. Prism Terminology
Apex: Tip of the prism where the two refracting
surfaces meet. Thinnest portion of the prism
Base
The bottom of the prism or the side opposite the
apex or apical angle
Thickest portion of the prism
Orientation of an ophthalmic prism is described
relative to the base
6. Prism Terminology
Refracting angle:
Angle included by the two faces of the prism
(β)(α)
Greater the angle, the more prism will deviate
light
Angle of Deviation:
Amount light deviates from its original path, in
degrees (ε)
7. Prism Action
a) Prism deviates light toward the base of the
prism
b) Objects appear to move toward apex of the
prism
c) Eye must make a movement toward apex to
maintain fixation on an object
d) Eye moves by an amount equal to the angle
of deviation
8. The deviation angle in a prism
depends upon:
Refractive index of the prism: Larger the refractive
index, the larger the deviation angle.
Angle of the prism: The larger the prism angle, the
larger the deviation angle.
Angle of incidence: The deviation angle depends on
the angle that the beam enters the object, called angle
of incidence. The deviation angle first decreases with
increasing incidence angle, and then it increases.
9.
10. Characteristic of prism
A prism does not change the vergence of
the rays.
A prism does not magnify or minify the
image.
A prism also disperses incident pencil
rays into its component colours.
11. Image formation
The object being viewed through the prism
appears displaced toward the apex of the
prism.
Although the light rays themselves bent
toward the base
The image formed by a prism is erect virtual
& displaced towards the apex of the prism.
12. There are two primary positions in which
the power of a prism may be specified
a) The position of minimum deviation
b) The prentice position.
13. The deviation angle & Angle of
minimum deviation
A beam passing through an object like a prism or
water drop is deflected twice: once entering, and
again when exiting. The sum of these two
deflections is called the deviation angle.
14. A ray of light is
deflected twice in a
prism. The sum of
these deflections is
the deviation angle.
When the entrance
and exit angles are
equal, the deviation
angle of a ray
passing through a
prism will be a
minimum.
15. Angle of deviation is least when the angle
of incidence equals the angle of
emergence
The angle of deviation equals half the
refracting angle of the prism
17. The Prentice position
The Prentice position is an orientation of a
prism, used in optics and ophthalmology. In
this position, light enters it at an angle of
90° to the first surface, so that the beam
does not refract at that surface. All the
deviation caused by the prism takes place at
the exit surface.
18. The Prentice position
The deviation of light in the prentice position
is greater than that in the position of
minimum deviation, because in the prentice
position the angle of incidence does not equal
the angle of emergence. Therefore the
Prentice position power of any prism is
greater than its power in the position of
minimum deviation.
19. • In ophthalmology, glass prisms, e, g, trial
lens prism, were classically calibrated for
use in the Prentice position,
• while plastic prisms, i, e, prism bars were
calibrated for use in the frontal position.
20. For example, a 40 dioptre plastic prism held
in the frontal plane will have an effective
power of 41 diopters,
but if it is held in the prentice position its
effective power becomes 72 diopters.
21. Notation of prism
The power of any prism can be express in
various units.
The Prism Dioptre (∆)
A prism of one dioptre power (1∆) produces
a liner apparent displacement of 1 cm, of an
object O, situated at 1 m.
22. Notation of prism
Angle of apparent deviation:
Under condition of ophthalmic usage a
prism of 1 prism dioptre power produces an
angle of apparent deviation of ½ 0. Thus 1
prism dioptre= ½ 0
(Prism diopters in the US and degrees in Europe)
23. Notation of prism
Centrad (𝛻):
This unit differs from the prism dioptre
only in that the image displacement is
measured along an arc 1 m from the prism.
The centrad produces a very slightly greater
angle of deviation than the prism dioptre,
but the difference, in practice, is negligible.
24.
25. Use of prism
1) Diagnostic
2) Therapeutic
3) Instruments
4) Miscellaneous
26. Diagnostic use of PRISM
Assessment of squint & heterophoria
a) Measurement of angle objectively by prism cover test
b) Measurement of angle subjectively by maddox rod
c) To assess likelihood of diplopia after proposed squint
surgery in adults.
d) Measurement of fusional reserve
e) 4 ∆D base out test
28. prism cover test: Procedure
The prism cover test measures the angle of deviation
on near or distance fixation and in any gaze position.
It combines the alternate cover test with prisms and
is performed as follows:
The alternate cover test is first performed to
establish the direction and approximate extent of
deviation.
29. Prisms of increasing strength are placed in front of one
eye with the base opposite the direction of the
deviation
For example, in a convergent strabismus the prism is
held base-out, and in a right hypertropia, base down
before the right eye.
30. The alternate cover test is performed continuously as
stronger prisms are introduced, typically using a prism
bar consisting of a column of prisms of progressive
strength. The amplitude of the re-fixation movement
should gradually decrease as the strength of prism
approaches the extent of deviation.
31. The end-point is approached when no movement is
seen. To ensure the maximum angle is found, the prism
strength can be increased further until a movement is
observed in the opposite direction (the point of
reversal) and then reduced again to find the neutral
value; the angle of deviation is then taken from the
strength of the prism.
32. Measurement of angle subjectively by
Maddox rod
• The Maddox rod consists of a series of fused
cylindrical red glass rods that convert the appearance
of a white spot of light into a red streak. The optical
properties of the rods cause the streak of light to be
at an angle of 90° with the long axis of the rods;
when the glass rods are held horizontally, the streak
will be vertical and vice versa.
33. The rod is placed in front of the right eye (Fig: A). This
dissociates the two eyes: the red streak seen by the right eye
cannot be fused with the unaltered white spot of light seen by
the left eye (Fig: B).
The amount of dissociation (Fig: C) is measured by the
superimposition of the two images using prisms. The base of
the prism is placed in the position opposite to the direction of
the deviation.
Both vertical and horizontal deviations can be measured in
this way but the test cannot differentiate a phoria from a
tropia.
37. • Maddox wing
• The Maddox wing dissociates the eyes for
near fixation (1/3 m)
• and measures heterophoria.
38. Maddox wing
The Maddox wing
dissociates the
eyes for near
fixation (1/3 m) and
measures heterophoria.
39. To assess likelihood of diplopia after
proposed squint surgery in adults.
Squint surgery in adult sometimes may cause
intractable diplopia, but before surgery if we
assess the squint with prism we can be aware of it
to the patient.
40. Measurement of fusional reserve
Increasingly powerful prisms are placed before one
eye until fusion breaks down. This is very useful in
assessing the presence of binocular vision in
children below two years of age.
41. 4 ∆D base out test
This is a delicate test for small degrees of esotropia
(microtropia). A four-diopter prism placed base-out
before the deviating eye causes no movement as
the image remains within the suppression scotoma.
When placed before the normal (fixing) eye,
movement occurs.
42. Forms of diagnostic prisms
i. Single un mounted prisms
ii. Trial lens set prisms
iii. Prism bars: These are bars composed of
adjacent prisms of increasing power.
44. Therapeutic prism: Convergence
insufficiency
The commonest therapeutic use of prisms in
the orthoptic department is in building up
the fusional reserve of patients with
convergence insufficiency.
45. Convergence insufficiency: Base out
prism exercises
Base out prisms can also be used to
stimulate the converge reflex. The base out
prism induces crossed diplopia and the
patient must converge to overcome the
prism strength and obtain BSV.
46. Convergence insufficiency: Base out
prism exercises
• Some practitioners give a patient a single
prism and have them do gradual exercises
or near tasks, while other practitioners
have the patient use a prism bar and to
overcome increasing prism strengths
while focusing on a near target.
47. To relieve diplopia
To relieve diplopia in certain cases of
squint, these include decompanseted
heterophorias, small vertical squints and
some paralytic squints with diplopia in the
primary position. Prisms are reserved for
those patients for whom surgery is not
indicated
48. Forms of therapeutic prism
Temporary wear prisms: Used in treatment include clip-
on spectacle prisms for trial wear. Eg:-Fresnel prism
(pronounced fre-nell') prisms,)
• To understand how a Fresnel prism works, imagine
cutting off the tops of a large number of equally
powered prisms and gluing them, one above the other,
onto a thin piece of plastic. A Fresnel prism is only 1
mm thick. It consists of plastic sheet of parallel tiny
prisms of identical refracting angle. The overall
prismatic effect is the same as that of a single large
prism. The sheets are lighter than a glass prism and can
be stuck on to the patient’s glasses.
49. • Advantages of a Fresnel Prism: It is very thin and
extremely lightweight. It is flexible and can be
applied to an existing spectacle lens. It can be cut
to any shape with scissors or a razor blade.
Reduce magnification differences considerably.
• Disadvantages: They are harder to clean than
conventional lenses. Fresnel prisms also cause a
slight loss of visual acuity caused by reflections
for prisms greater than 10Δ.
50.
51. Prisms in optical instruments:
1) Slit lamp bio microscope.
2) Applanation tonometer
3) keratometer
52. Different types of prism used in
ophthalmology
Porro-prism: , is a type of reflection prism used in
optical instruments to alter the orientation of an image.
• Porro prisms are most often used in pairs, forming
a double Porro prism. A second prism, rotated 90°
with respect to the first, is placed such that light will
traverse both prisms. The net effect of the prism
system is a beam parallel to but displaced from its
original direction, with the image rotated 180°. As
before, the handedness of the image is unchanged.
53. • Double Porro prism systems are used in small optical
telescopes to re-orient an inverted image (an
arrangement is known as an image erection system),
and especially in many binoculars where they both
erect the image and provide a longer, folded distance
between the objective lenses and the eyepieces.
• Commonly, the two components of the double
Porro system are cemented together, and the prisms
may be truncated to save weight and size.
55. • Dove prism:
• A Dove prism is a type of reflective prism which is
used to invert an image. Dove prisms are shaped
from a truncated right-angle prism. A beam of
light entering one of the sloped faces of the prism
undergoes total internal reflection from the
inside of the longest (bottom) face and emerges
from the opposite sloped face. Images passing
through the prism are flipped, and because only
one reflection takes place, the image is inverted
but not laterally transposed.
56. Dove prism:
A Dove prism is a type of reflective prism which is
used to invert an image. Dove prisms are shaped
from a truncated right-angle prism. A beam of light
entering one of the sloped faces of the prism
undergoes total internal reflection from the inside of
the longest (bottom) face and emerges from the
opposite sloped face. Images passing through the
prism are flipped, and because only one reflection
takes place, the image is inverted but not laterally
transposed.
57. The Wollaston prism
• A Wollaston prism is an optical device,
invented by William Hyde Wollaston, that
manipulates polarized light. It separates light
into two separate linearly polarized outgoing
beams with orthogonal polarization. The two
beams will be polarized according to the
optical axis of the two right angle prisms.
58. The Wollaston prism
• The Wollaston prism consists of two
orthogonal prisms of birefringent material—
typically a uniaxial material such as calcite.
These prisms are cemented together on their
base (traditionally with Canada balsam) to form
two right triangle prisms with perpendicular
optic axes.
59. The Wollaston prism
• Outgoing light beams diverge from the prism as
ordinary and extraordinary rays due to the
differences in the indexes of refraction, with the
angle of divergence determined by the prisms'
wedge angle and the wavelength of the light.
Commercial prisms are available with divergence
angles from less than 1° to about 45°.
• Use in: Keratometer