EYE DISEASE GUIDE: GLAUCOMA AND CATARACTS

GLAUCOMA
&
CATARACT
Mathew Varghese V
MSN(RAK),FHNP (CMC Vellore),CPEPC
Nursing officer
AIIMS Delhi
1mathewvmaths@yahoo.co.in

Glaucoma
Epidemiology
 Leading causes of irreversible blindness in the
world
 More prevalent among people older than 40 years
of age
 Incidence increases with age.
 More prevalent among men than women
 More common in African American and Asian
populations.
 There is no cure for glaucoma, but research
continues
2
mathewvmaths@yahoo.co.in

What is Glaucoma
 Glaucoma is a complex disease in which
damage to the optic nerve due to increased
IOP leads to progressive, irreversible vision
loss.
3

Normal physiology of Aqueous
Humor
 Aqueous humor flows between the iris and the
lens, nourishing the cornea and lens.
 Most (90%) of the fluid then flows out of the
anterior chamber, draining through the spongy
trabecular meshwork into the canal of
Schlemm and the episcleral veins.
 About 10% of the aqueous fluid exits through
the ciliary body into the suprachoroidal space
and then drains into the venous circulation of
the ciliary body, choroid, and sclera.
4

Normal physiology of Aqueous
Humor
 The outflow of aqueous fluid depends on an
intact drainage system and an open angle
(about 45 degrees) between the iris and the
cornea.
 A narrower angle places the iris closer to the
trabecular meshwork, diminishing the angle.
 The amount of aqueous humor produced
tends to decrease with age, in systemic
diseases such as diabetes, and in ocular
inflammatory conditions.
5

IOP
 IOP is determined by the rate of aqueous
production, the resistance encountered by the
aqueous humor as it flows out of the passages,
and the venous pressure of the episcleral veins
that drain into the anterior ciliary vein.
 When aqueous fluid production and drainage are
in balance, the IOP is between 10 and 21 mm Hg.
 When aqueous fluid is inhibited from flowing out,
pressure builds up within the eye.
 Fluctuations in IOP occur with time of day,
exertion, diet, and medications.
6

Risk Factors
 Family history of glaucoma
 African American race
 Older age
 Diabetes
 Cardiovascular disease
 Migraine syndromes
 Nearsightedness (myopia)
 Eye trauma
 Prolonged use of topical or systemic
corticosteroids
7

Pathophysiology
 There are two accepted theories regarding
how increased IOP damages the optic nerve in
glaucoma.
 The direct mechanical theory
 The indirect ischemic theory
8

Stages
 1. Initiating events
 2. Structural alterations in the aqueous
outflow system
 3. Functional alterations:
 4. Optic nerve damage:
 5. Visual loss:
9

Types of Glaucoma
 Open-angle glaucoma (OAG)
 Narrow angle glaucoma.
10

Variations of OAG include
 Primary open angle glaucoma (POAG)
 Normal-tension glaucoma (NTG),
 Pigmentary glaucoma
 Pseudo exfoliation glaucoma
 Secondary glaucoma
 Congenital glaucoma.
11

Variations of narrow angle
glaucoma
 Acute angle closure glaucoma
 Chronic angle closure glaucoma
 Neovascular glaucoma.
12

Primary open-angle
glaucoma.(POAG)
 This common type of glaucoma gradually
reduces your peripheral vision without other
symptoms.
 By the time you notice it, permanent damage
already has occurred.
If your IOP remains high, the destruction
caused by POAG can progress until tunnel
vision develops, and you will be able to see
only objects that are straight ahead.
 Ultimately, all vision can be lost, causing
blindness
13

Acute angle-closure
glaucoma
 Also called narrow-angle glaucoma, acute angle-
closure glaucoma produces sudden symptoms
such as eye pain, headaches, halos around
lights, dilated pupils, vision loss, red eyes, nausea
and vomiting.
 These signs constitute a medical emergency.
 The attack may last for a few hours, and then
return again for another round, or it may be
continuous without relief.
 Each attack can cause progressively more vision
loss.
14

Normal-tension glaucoma.
 Like POAG, normal-tension glaucoma (also called normal-
pressure glaucoma, low-tension glaucoma or low-pressure
glaucoma) is a type of open-angle glaucoma that can cause
visual field loss due to optic nerve damage. But in normal-
tension glaucoma, the eye's IOP remains in the normal
range.
 Also, pain is unlikely and permanent damage to the eye's
optic nerve may not be noticed until symptoms such as tunnel
vision occur.
 The cause of normal-tension glaucoma is not known.
 But many doctors believe it is related to poor blood flow to the
optic nerve.
 Normal-tension glaucoma is more common in those who are
Japanese, are female and/or have a history of vascular
disease.
15

Secondary glaucoma.
 Symptoms of chronic glaucoma following
an eye injury could indicate secondary
glaucoma
 Which also may develop with presence of eye
infection, inflammation, a tumor or
enlargement of the lens due to a cataract.
16

Congenital glaucoma
 This inherited form of glaucoma is present at birth,
with 80 percent of cases diagnosed by age one.
 These children are born with narrow angles or
some other defect in the drainage system of the
eye.
 It's difficult to spot signs of congenital glaucoma,
because children are too young to understand
what is happening to them.
 If you notice a cloudy, white, hazy, enlarged or
protruding eye in your child, consult your eye
doctor.
 Congenital glaucoma typically occurs more in
boys than in girls.
17

Diagnosis, Screening and Tests
for Glaucoma
 Ocular History
 ocular examination
 Tonometer
 imaging technology
 Scanning laser polarimetry (SLP)
 Optical coherence tomography (OCT)
18

Diagnosis, Screening and Tests
for Glaucoma
 Confocal scanning laser ophthalmoscopy —
to create baseline images and measurements
of the eye's optic nerve and internal structures.
 Visual field testing
 Gonioscopy to evaluate the drainage angle.
 Ultrasound biomicroscopy is another
technique that may be used to evaluate the
drainage angle.
19

Medical Management
 The aim of all glaucoma treatment is prevention of
optic nerve damage through medical therapy, laser or
nonlaser surgery, or a combination of these
approaches.
 Lifelong therapy is almost always necessary because
glaucoma cannot be cured.
 Although treatment cannot reverse optic nerve
damage, further damage can be controlled.
 The treatment goal is to maintain an IOP within a
range unlikely to cause further damage.
 Treatment focuses on achieving the greatest benefit
at the least risk, cost, and inconvenience to the
patient.
20

Pharmacologic treatment
21

SURGICAL MANAGEMENT
 Laser trabeculoplasty
 In laser trabeculoplasty for glaucoma, laser burns are
applied to the inner surface of the trabecular meshwork
to open the intratrabecular spaces and widen the canal
of Schlemm, thereby pro-moting outflow of aqueous
humor and decreasing IOP.
 The procedure is indicated when IOP is inadequately
controlled by medications; it is contraindicated when the
trabecular meshwork cannot be fully visualized because
of narrow angles.
 A serious complication of this procedure is a transient
rise in IOP (usually 2 hours after surgery) that may
become persistent.
 IOP assessment in the immediate postoperative period
is essential.
22

Laser iridotomy
 In laser iridotomy for pupillary block glaucoma,
an opening is made in the iris to eliminate the
pupillary block.
 Laser iridotomy is contraindicated in patients with
corneal edema, which interferes with laser
targeting and strength.
 Potential complications are burns to the cornea,
lens, or retina; transient elevated IOP; closure of
the iridotomy; uveitis; and blurring.
 Pilocarpine is usually prescribed to prevent
closure of the iridotomy.
23

Filtering procedures
 Filtering procedures for chronic glaucoma
are used to create an opening or fistula in the
trabecular meshwork to drain aqueous humor
from the anterior chamber to the
subconjunctival space, thereby bypassing the
usual drainage structures.
 This allows the aqueous humor to flow and
exit by different routes (ie, absorption by the
conjunctival vessels or mixing with tears).
24

Trabeculectomy
 Trabeculectomy is the standard filtering
technique used to remove part of the
trabecular meshwork.
 Complications include
 hemorrhage, an extremely low (hypotony) or
elevated IOP,
 uveitis,
 cataracts,
 endophthalmitis.
25

Drainage implants or shunts
 Drainage implants or shunts are open tubes
implanted in the anterior chamber to shunt
aqueous humor to an attached plate in the
conjunctival space.
 A fibrous capsule develops around the
episcleral plate and filters the aqueous humor,
thereby regulating the outflow and controlling
IOP.
26

Nursing Management
 Disturbed Visual Sensory Perception
related to increased ocular pressure as
evident by progressive loss of visual field
 Anxiety related to Physiological factors,
change in health status; presence of pain;
possibility/reality of loss of vision
 Deficient Knowledge related to lack of
exposure/unfamiliarity with resources
27

Cataracts
 What Is a Cataract?
 A cataract is a dense, cloudy area that forms in
the lens of the eye.
 A cataract begins when proteins in the eye form
clumps that prevent the lens from sending clear
images to the retina.
 The retina works by converting the light that
comes through the lens into signals. It sends the
signals to the optic nerve, which carries them to
the brain. It develops slowly and eventually
interferes with your vision.
28

causes
 Ageing
 An overproduction of oxidants, which are oxygen
molecules that have been chemically altered due
to normal daily life
 Smoking
 Ultraviolet radiation
 The long-term use of steroids and other
medications
 Certain diseases, such as diabetes
 Trauma
 Radiation therapy
29

Risk factors
 Aging
 • Loss of lens transparency
 • Clumping or aggregation of lens protein (which
leads to light scattering)
 • Accumulation of a yellow-brown pigment due to
the breakdown of lens protein
 • Decreased oxygen uptake
 • Increase in sodium and calcium
 • Decrease in levels of vitamin C, protein, and
glutathione (an antioxidant)
30

Associated Ocular
Conditions
 Retinitis pigmentosa
 • Myopia
 • Retinal detachment and retinal surgery
 • Infection (eg, herpes zoster, uveitis)
31

Toxic Factors
 Corticosteroids, especially at high doses and
in long-term use
 Alkaline chemical eye burns, poisoning
 Cigarette smoking
 Calcium, copper, iron, gold, silver, and
mercury, which tend to deposit in the pupillary
area of the lens
32

Nutritional Factors
 Reduced levels of antioxidants
 • Poor nutrition
 • Obesity
33

Physical Factors
 Dehydration associated with chronic diarrhea,
use of purgatives in anorexia nervosa, and use
of hyperbaric oxygenation
 Blunt trauma, perforation of the lens with a
sharp object or foreign body, electric shock
 Ultraviolet radiation in sunlight and x-ray
34

Systemic Diseases and
Syndromes
 Diabetes mellitus
 Down syndrome
 Disorders related to lipid metabolism
 Renal disorders
 Musculoskeletal disorders
35

Types of Cataracts
 Nuclear cataracts form in the middle of the
lens and cause the nucleus, or the center, to
become yellow or brown.
 Cortical cataracts are wedge-shaped and
form around the edges of the nucleus.
 Posterior capsular cataracts form faster than
the other two types and affect the back of the
lens.
 Congenital cataracts, which are present at
birth or form during a baby’s first year, are less
common than age-related cataracts
36

Types of Cataracts
 Secondary cataracts are caused by disease
or medications. Diseases that are linked with
the development of cataracts include
glaucoma and diabetes. The use of the steroid
prednisone and other medications can
sometimes lead to cataracts.
 Traumatic cataracts develop after an injury to
the eye, but it can take several years for this to
happen.
 Radiation cataracts can form after a person
undergoes radiation treatment for cancer.
37

Symptoms of Cataracts
 blurry vision
 trouble seeing at night
 seeing colors as faded
 increased sensitivity to glare
 halos surrounding lights
 double vision in the affected eye
 a need for frequent changes in prescription
glasses
38

Diagnosing Cataracts
 ocular history
 ocular examination
 snellen’s Chart Examination
 Tonometry to measure eye pressure.
 Slit-lamp exam
 Retinal exam
 Refraction and visual acuity test
39

Medical Management
 No nonsurgical treatment cures cataracts.
 Ongoing studies are investigating ways to slow
cataract progression, such as intake of
antioxidants (eg, vitamin C, beta-carotene,
vitamin E)
 Reducing glare with proper light and
appropriate lighting can facilitate reading.
 Mydriatics can be used as short-term
treatment to dilate the pupil and allow more
light to reach the retina, although this
increases glare.
40

Surgical Management
 Phacoemulsification (Using an ultrasound probe
to break up the lens for removal)
 During a procedure called phacoemulsification
,surgeon makes a tiny incision in the front of eye
(cornea) and inserts a needle-thin probe into the lens
substance where the cataract has formed.
 Surgeon then uses the probe, which transmits
ultrasound waves, to break up (emulsify) the cataract
and suction out the fragments. The very back of lens
(the lens capsule) is left intact to serve as a place for
the artificial lens to rest. Stitches may or may not be
used to close the tiny incision in cornea at the
completion of the procedure.
41

Surgical Management
 Laser-assisted cataract surgery (Using an
advanced laser technique to remove the
cloudy lens.)
 In laser-assisted cataract surgery, the surgeon
uses a laser to make all incisions and soften
the cataract for removal.
42

Surgical Management
 Extra capsular cataract extraction (Making an incision in
the eye and removing the lens in one piece)
 A less frequently used procedure called extracapsular
cataract extraction requires a larger incision than that used
for phacoemulsification. Through this larger incision surgeon
uses surgical tools to remove the front capsule of the lens
and the cloudy portion of the lens comprising the cataract.
The very back capsule of the lens is left in place to serve as a
place for the artificial lens to rest.
 This procedure may be performed if patient has certain eye
complications. With the larger incision, stitches are required.
 Once the cataract has been removed by either
phacoemulsification or extracapsular extraction, the artificial
lens is implanted into the empty lens capsule.
43

Potential Complications of
Cataract Surgery
 Inflammation
 Infection
 Bleeding
 Swelling
 Drooping eyelid
 Dislocation of artificial lens
 Retinal detachment
 Glaucoma
 Secondary cataract
 Loss of vision
44

Nursing Management
 Disturbed Sensory Perception: Visual:
related to cataracts
 Risk for Injury related to Decreased vision
45

Conclusion
 Prevention of cataract includes risk factors reduction
such as UVB exposure and smoking can be
addressed.
 Although no means of preventing cataracts has been
scientifically proven, wearing sunglasses that
counteract ultraviolet light may slow their
development.
 While adequate intake of antioxidants (such as
vitamins A, C, and E) has been thought to protect
against the risk of cataracts, clinical trials have shown
no benefit from supplements; though evidence is
mixed, but weakly positive, for a potential protective
effect of the nutrients lutein and zeaxanthin. Statin use
is somewhat associated with a lower risk of nuclear
46

Bibliography
 Field D, Tillotson J, Whittingham E (2015) Eye
Emergencies - The Practitioners Guide. Second
edition. M&K Publishing, Keswick.
Grasso J, Long J, McCulloch J, Moore C (2008) Eye
Examination. tinyurl.com/qgaw49o (Last accessed:
October 30 2015.)
 Marsden J (2002) Ophthalmic trauma in the
emergency department. Accident and Emergency
Nursing. 10, 3, 136-142.
 Marsden J (2006) Ophthalmic Care. Wiley-Blackwell,
Chichester. Patient (2013) Examination of the Eye.
www.patient. co.uk/doctor/examination-of-the-eye
(Last accessed: October 30 2015.)
48

Thank You
49

EYE DISEASE GUIDE: GLAUCOMA AND CATARACTS

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EYE DISEASE GUIDE: GLAUCOMA AND CATARACTS