| FUNDUS FLUORESCEIN ANGIOGRAM |
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| This is a very important
diagnostic test for retinal diseases. The patient is
seated in the front of the camera. Fluorescein dye is
injected into the vein. Photographs or Video Angiographs
are taken |
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| Side effects: |
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| Temporary discoloration of
urine & skin |
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| Mild vomiting |
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| Very rarely allergic reactions |
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| How we perform Fundus Fluorescein
Angiogram ? |
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| We have the facility of real
time angiography where we videograph the whole sequence
of the angiogram. |
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| Patients and the accompanying
attendants can view the video angiograph directly for
a better understanding of the problem. |
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| Indocyanine green angiography: |
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Indocanine green dye is used
To study the choroidal diseases
Other procedures similar to Fundus Fluorescein Angiogram |
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| Indirect
ophthalmoscopy & Retinal examination |
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| How we examine the retina
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| To study the central &
peripheral retina in detail. |
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Pupils are well dilated.
Patient examined in lying posture. |
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| Examination of retina using
special lenses. |
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| Retina |
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| The retina is the delicate
lining at the back of the eye that functions much like
the film in a camera. It receives light through the
lens in your eye, forms that light into images, and
sends those images to the brain, enabling you to see. |
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| Vitreous |
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| The vitreous is the clear,
gel-like mass that fills the space between the lens
and the retina. |
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| Vitrectomy |
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| Vitrectomy means to remove
the vitreous humor. Vitreous pulls on the retina creating
retinal tears or breaks. The vitreous never regenerates
if it is removed, and the eye will have perfect vision
and a normal shape without the vitreous. Vitreous removal
reduces pulling (traction) on the retina, improves the
surgeon's view, and provides space for a gas or silicone
oil bubble. |
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| Scleral
buckle |
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| Scleral buckles are permanent
components usually made of silicone rubber or silicone
sponge material which are sutured to the outside surface
of the back half of the eye in order to create a permanent
indentation of the retinal pigment epithelium, choroid,
and sclera, which are the three layers of tissue under
the retina, which are pushed inward against the retina.
The buckling effect is placed adjacent to the retinal
breaks, holes, and tears to help seal or support them.
A secondary purpose of scleral buckles is to reduce
pulling on the retina due to contraction of the collagen
fibers in the vitreous humor. This works by pushing
the retina inward. |
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| Flashes |
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Light flashes are sometimes
caused by mechanical stimulation of the retina, often
referred to as "pulling forces", or "traction".
A variety of conditions can cause it, including: |
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| Posterior vitreous separation, |
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| Retinal tears (breaks), and
scarring on the surface of the retina. |
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| Floaters |
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| loaters are relatively transparent,
vague, usually curved objects that are seen best when
looking at a white piece of paper, blue sky, light colored
ceiling, or wall. They sometimes look like cobwebs,
worms, rings, dots, or specks. Eye movement makes floaters
more visible as they swirl about like seaweed in the
ocean surf. |
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| Diabetic retinopathy |
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Diabetic retinopathy results
from the effects of diabetes on blood vessels in the
retina. Diabetes causes retinal blood vessels to leak
and grow abnormally.
There are two main stages of diabetic retinopathy: |
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| Non-proliferative |
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| Proliferative |
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| Hypertensive
retinopathy |
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| Is a disorder affecting the
retinal arteries and nerves due to long standing uncontrolled
hypertension. |
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| Central
Serous Retinopathy (CSR) |
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| A self-limiting disease of
young or middle-aged adult males. |
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| RETINAL
VEIN OCCLUSION |
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| Obstruction of the retinal
veins due to |
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| Increasing age |
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| Hypertension |
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| Diabetes |
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| Blood dyscrasias |
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| Glaucoma |
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| Periphlebitis |
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| Retinal
Detachment |
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| A retinal detachment is a
separation of the retina from the back wall of the eye.
When there is a tear of the retina, liquid from the
vitreous may pass through the tear, and detach the retina. |
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| ARMD
[ Age Related Macular Degeneration] |
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| ARMD is the leading cause
of irreversible severe visual loss in old age. The prevalence
of severe visual loss increase with age. In INDIA at
least 30% of individuals between the ages of 65 and
75 have lost some central vision as a result of ARMD. |
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| Macular
Hole |
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| Macular hole is a common
cause of visual morbidity, usually affects older females |
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| Retinoblastoma |
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| Although the disease is very
rare, retinoblastoma (RB) is the most common eye tumor
in children, and the third most common cancer overall
affecting children. Retinoblastoma is a disease that
causes the growth of malignant tumors in the retinal
cell layer of the eye. The frequency of retinoblastoma
has increased over the past 60 years. It now occurs
in 1 out of every 15,000 live birth.
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| Laser
Photocoagulation |
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| LASER is an acronym of Light
Amplification by Stimulated Emission of Radiation. The
principle of Retinal laser photocoagulation is the absorption
of light energy by ocular pigments and conversion into
heat.The purpose of laser therapy is to produce a therapeutic
burn to a pre-selected area of the retina while causing
minimal damage to surrounding tissues.
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| Indications for laser photoagulation
are to treat |
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| Retinal vascular diseases |
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| Macular choroidal neovascular
membranes |
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| Retinal breaks |
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| Predisposing peripheral degeneration |
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| Certain intraocular tumours. |
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| Main lasers used for retinal
photocoagulation |
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| Argon Laser , coherent blue-green
light of about of 488-515nm. Preferred when treatment
is required close to the fovea. |
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| Krypton yellow, emits light
at about 577nm. Ability to directly coagulate red lesions. |
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| Diode laser, emits infrared
light of 780 to 950nm |
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| Delivery systems |
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| Slitlamp delivery |
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| Indirect ophthalmoscope delivery |
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| Intraocular (endolaser) |
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| Complications |
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| Very rare |
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Macular damage due to foveal
burn, macular oedema, macular pucker
Choroidal haemorrhage, Contraction of fibrous tissue |
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| Micro
aneurysms |
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| Microaneurysms are located
in the inner nuclear layer of the retina and are the
first clinically detectable lesions of Diabetic retinopathy.
They appear as small round dots, usually temporal to
the macula. When coated with blood they may be indistinguishable
from dot haemorrhage. |
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| Intraretinal
haemorrhages |
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| Intraretinal haemorrages
originating from the venous end of the capillaries are
located in the compact middle layers of the retina,
and have a ‘dot-blot’ configuration, Flame-shaped
haemorrhages, which originate from the more superficial
precapillary arterioles, follow the course of the retinal
nerve fibre layer. |
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| Hard
exudates |
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| Hard exudates are located
between the inner plexiform and inner nuclear layers
of the retina. They have a yellow waxy appearance with
relatively distinct margins. They are arranged in clumps
and/or rings, most frequently at the posterior pole.
The centers of rings of hard exudates usually contain
microaneurysms. With time the number and size of hard
exudates tends to increase. |
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| Retinal
oedema |
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| Retinal oedema is initially
located between the outer plexiform and inner nuclear
layers. Later it may involve the inner plexiform and
nerve fibre layers, until eventually the entire thickness
of the retina may become oedematous. With further accumulation
of fluid of the fovea assumes a cystoid appearance.
Clinically, retinal oedema is characterized by retinal
thickening which obscures the underlying retinal pigment
epithelium and choroids. It is best detected by slitlamp
biomicrooscopy with a +78D lens. |
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| Soft
Drusen |
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| Soft Drusen are larger than
hard drusen and have indistinct edges. With time they
may slowly enlarge and coalesce. Confluent drusen are
associated with diffuse dysfunction of the RPE and an
increased risk of a subsequent CNV. |
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| Hard
Drusen |
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| Hard Drusen are small, discrete,
yellow-white spots which are associated with focal dysfunction
of the RPE. In the majority of patients they are innocuous. |
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| PHOTODYNAMIC
THERAPY ( PDT ) |
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| Photodynamic therapy uses
a photoreactive drug to achieve oxidative destruction
of CNV. |
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| Preservation of photoreceptor
outer segments, choriocapillaries and retinal pigment
epithelium were detected histologically in areas where
experimental CNV had been occluded. |
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| The two-step Photo-Point
procedure involves the intravenous infusion of the photosensitizer,
followed within 15 minutes later by a precise application
of non-thermal 664nm light. |
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| More effective and less damaging
treatment. |
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| Avoids thermal destruction
of the retina. |
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| Visudyne is a light-activated
drug that accumulates selectively in neovasculature,
including CNV. |
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| Activated by a non-thermal
laser, can temporarily stop leakage from CNV without
damaging the overlying retinal tissue. |
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| Re-treatments may be necessary. |
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| Reduces the risk of vision
loss and limit the the destruction of the retina overlying
CNV. |
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| Breakthrough in the treatment
of classic sub-foveal CNV |
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| TRANSPUPILLARY
THERMOTHERAPY (TTT) |
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| No visible color change is
seen at the end of treatment. |
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| Hyperthermia treatment minimizes
tissue coagulation to surrounding tissues and deep penetration
to the choroid and retinal pigment epithelium can be
optimized. |
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| Acute loss of vision after
treatment not reported. |
