OPHTHALMOLOGY
PREPARED BY MR. ABHIJIT DAS
BACTERIAL AND VIRAL CONJUCTIVITIS
Bacterial and viral conjunctivitis are two different
types of eye infections that affect the conjunctiva, which is the thin, clear
layer that covers the white part of the eye and the inside of the eyelid.
Bacterial conjunctivitis:
- Caused
by bacteria such as Staphylococcus aureus, Streptococcus pneumoniae, or
Haemophilus influenzae
Viral conjunctivitis:
- Caused
by a virus such as adenovirus, herpes simplex virus, or varicella-zoster
virus
ETIOPATHOGENESIS
Bacterial conjunctivitis is caused by bacterial
infections, most commonly Staphylococcus aureus, Streptococcus pneumoniae, or
Haemophilus influenzae. These bacteria can enter the eye through direct contact
with contaminated hands or objects, or through respiratory droplets from an
infected person. Bacterial conjunctivitis can also occur as a secondary
infection in individuals with pre-existing eye conditions, such as dry eyes or
blepharitis.
Viral conjunctivitis is caused by a viral infection,
typically adenovirus, herpes simplex virus, or varicella-zoster virus.
Adenovirus is the most common cause of viral conjunctivitis, and it can be
spread through direct or indirect contact with infected individuals, as well as
through respiratory droplets. Herpes simplex virus and varicella-zoster virus
are less common causes of viral conjunctivitis, and they are typically
associated with systemic infections.
The mechanisms by which bacteria and viruses cause
conjunctivitis are different. Bacteria can directly damage the conjunctiva by
producing toxins or by inducing an immune response, resulting in inflammation
and redness. Viruses can also induce an immune response, but they primarily
cause conjunctivitis by infecting and damaging the conjunctival cells.
CLINICAL MANIFESTATIONS
Clinical Manifestations of Bacterial Conjunctivitis:
- Eye
redness
- Eye
discharge that is thick and pus-like, which can cause the eyelids to stick
together upon waking up
- Eye
irritation or itchiness
- Swollen
eyelids
- Blurred
vision
- Tearing
Clinical Manifestations of Viral Conjunctivitis:
- Eye
redness
- Eye
discharge that is watery
- Eye
irritation or itchiness
- Swollen
eyelids
- Photophobia
(sensitivity to light)
- Tearing
- Upper
respiratory symptoms, such as sore throat, runny nose, and cough
- Enlarged
lymph nodes around the ear or neck
NON-PHARMACOLOGICAL MANAGEMENT
Non-pharmacological management of bacterial and
viral conjunctivitis can help to relieve symptoms and prevent the spread of
infection. Here are some measures that can be taken:
1.
Practice good hygiene: Wash your hands
frequently and avoid touching your eyes. Use a clean towel or tissue to wipe
your eyes and face.
2.
Avoid contact lenses: Avoid wearing
contact lenses until the infection has cleared up. If you must wear them, make
sure to clean them thoroughly and dispose of them after the infection has
cleared up.
3.
Use cool compresses: Apply a clean, cool
compress to your eyes for several minutes at a time to help relieve itching and
irritation.
4.
Avoid sharing personal items: Avoid
sharing towels, eye makeup, or other personal items that may come into contact
with your eyes.
5.
Clean and disinfect surfaces: Clean and
disinfect surfaces that may be contaminated with the bacteria or virus, such as
doorknobs, countertops, and bathroom fixtures.
6.
Rest your eyes: Rest your eyes as much
as possible, and avoid activities that may cause eye strain or irritation.
PHARMACOLOGICAL MANAGEMENT
Pharmacological management of bacterial and viral
conjunctivitis typically involves the use of topical medications that are
applied directly to the eye. The choice of medication depends on the underlying
cause of the conjunctivitis, whether it is bacterial or viral. Here are some
common medications used to treat bacterial and viral conjunctivitis:
1.
Antibiotics: Topical antibiotics are
typically used to treat bacterial conjunctivitis. Antibiotics work by killing
the bacteria that are causing the infection. Commonly used antibiotics include
sulfonamides, aminoglycosides, and fluoroquinolones.
2.
Antivirals: Topical antiviral
medications are used to treat viral conjunctivitis caused by herpes simplex
virus or varicella-zoster virus. Antivirals work by preventing the virus from
replicating and spreading. Commonly used antivirals include acyclovir,
ganciclovir, and trifluridine.
3.
Lubricating eye drops: Lubricating eye
drops can be used to relieve symptoms of both bacterial and viral
conjunctivitis, such as dryness and irritation. These drops help to moisturize
the eyes and alleviate discomfort.
GLAUCOMA
DEFINITION
Glaucoma is a group of eye disorders that cause
damage to the optic nerve, resulting in progressive vision loss. It is
characterized by increased intraocular pressure (IOP), which can cause damage
to the optic nerve over time. Glaucoma is a leading cause of blindness
worldwide and can affect people of all ages, although it is more common in
people over 60 years of age.
ETIOPATHOGENESIS
The most common form of glaucoma, open-angle
glaucoma, is believed to be caused by a combination of factors that lead to an
increase in IOP. This increase in pressure may be due to a blockage in the
trabecular meshwork, which is responsible for draining the aqueous humor from
the eye. This blockage may be caused by a buildup of debris or a dysfunction in
the cells of the trabecular meshwork.
Angle-closure glaucoma, on the other hand, is caused
by a sudden blockage of the drainage angle, which can cause a rapid increase in
IOP. This can occur when the iris bulges forward and blocks the drainage angle,
or when the lens of the eye becomes displaced and pushes against the iris.
CLINICAL MANIFESTATIONS
1.
Gradual loss of peripheral vision: This
is often the first symptom of glaucoma and may not be noticeable until
significant vision loss has occurred.
2.
Blurred or hazy vision: This may be more
noticeable when looking at distant objects.
3.
Halos or rainbows around lights: This
may be due to increased pressure on the optic nerve.
4.
Difficulty adjusting to dark rooms: This
may be due to damage to the light-sensitive cells in the eye.
5.
Eye pain or discomfort: This may occur
during an acute episode of angle-closure glaucoma.
6.
Redness in the eye: This may occur
during an acute episode of angle-closure glaucoma.
NON-PHARMACOLOGICAL MANAGEMENT
1.
Exercise regularly: Regular physical
activity can help reduce IOP and improve blood flow to the optic nerve.
2.
Maintain a healthy diet: A healthy diet
can help reduce IOP and improve overall eye health. Eating a diet rich in
fruits, vegetables, whole grains, lean protein, and healthy fats can help
reduce the risk of glaucoma.
3.
Manage stress: High levels of stress can
cause an increase in IOP. Managing stress through relaxation techniques such as
meditation, yoga, or deep breathing exercises can help reduce IOP.
4.
Avoid smoking and alcohol: Smoking and
excessive alcohol consumption can increase the risk of glaucoma and worsen the
condition.
5.
Protect your eyes: Protecting your eyes
from UV rays and other environmental factors can help reduce the risk of
glaucoma.
6.
Get regular eye exams: Regular eye exams
are important for the early detection and treatment of glaucoma. During an eye
exam, the doctor can measure IOP and check for signs of optic nerve damage.
PHARMACOLOGICAL MANAGEMENT
Pharmacological management of glaucoma involves the
use of medication to reduce intraocular pressure (IOP) and prevent further
damage to the optic nerve. There are several classes of medications used to
treat glaucoma, including:
1.
Prostaglandin analogs: These medications
work by increasing the outflow of aqueous humor from the eye, reducing IOP.
Examples include latanoprost, bimatoprost, and travoprost.
2.
Beta-blockers: These medications reduce
IOP by decreasing the production of aqueous humor. Examples include timolol,
betaxolol, and levobunolol.
3.
Alpha-adrenergic agonists: These
medications work by decreasing the production of aqueous humor and increasing
its outflow. Examples include brimonidine and apraclonidine.
4.
Carbonic anhydrase inhibitors: These
medications reduce IOP by decreasing the production of aqueous humor. Examples
include dorzolamide and brinzolamide.