Difference between Bacterial and Viral Conjunctivitis

Difference between Bacterial and Viral Conjunctivitis

Conjunctiva is a thin translucent membrane and covers the under surface of the eyelids and is reflected over eyeball.  It has three parts, each of them have separate locations and functions. It also has glands which are celled lacrimal glands and mucous glands. It derives its blood supply from anterior and posterior conjunctival arteries. It has two basic functions. One is to make a connection between eyeball and eyelids and other is maintenance of lubrication of eye through production of fluids from glands. As it is the exposed part of eye, so it is subject to various insults which may be bacterial, viral or mechanical trauma.

Bacterial Conjunctivitis

Bacteria are the most general cause of conjunctivitis. It is further divided into three types i.e. muco purulent conjunctivitis, purulent conjunctivitis and membranous conjunctivitis. Muco purulent variety is acute inflammation of conjunctiva so it is also called ‘pink eye’.  Bacteria causing the problem are staphylococcus, nesseria, gonorrhoeae and klebsiella. It is common but self -limiting disease. Purulent type is characterized by presence of discharge which has pus along with redness of eyes. Source of infection is from genitourinary tract infection. Third variety is caused by corynebacterium diphtheria and is very rare nowadays. All of these forms can result in complications if left untreated.

Viral Conjunctivitis

It is also acute inflammation of the conjunctiva which causes discharge from eyes but this discharge is watery and patient also has redness of eyes. The common viruses causing this condition include adenovirus, picovirus, herpes virus and chicken pox virus. Each of these types has distinguishing features which can be picked up clinically. Viral conjunctivitis mainly affects both the eyes. This is usually self -limiting disease and requires anti-viral therapy only if complicated.

Bacterial VS Viral Conjunctivitis

Cause:

Bacterial conjunctivitis is caused by different bacteria.

Viral conjunctivitis is caused by viral species.

Species:

Bacterial species include staphylococcus, streptococcus, nesseria, hemophilus, Proteus and klebsiella.

Viral species include adenovirus, picovirus, measles and chicken pox virus.

Types:

Bacterial conjunctivitis has three types i.e. mucopurulent, purulent and membranous.

Viral conjunctivitis has no such types.

Clinical features:

Bacterial conjunctivitis is associated with discharge which has pus and redness of eyes.

Purulent discharge is associated with watery discharge and redness of eyes.

Signs:

Eyelashes are matted, eyelid margins have discharge and eye is fully or partially red.

Eyelids have vesicles; conjunctiva is red and a pseudo membrane may be present.

Diagnosis:

Bacterial variety is diagnosed through clinical assessment and investigations are not required.

Viral type is diagnosed through clinical features along with antibody titre and detection of antigen in cells.

Treatment:

Bacterial type is treated through antibiotic ointments and drops.

Viral type is treated through anti-viral drugs.

Use of steroids:

Steroids can be used in bacterial type.

Steroids are contraindicated in viral variety.

Conclusion

Conjunctiva, being the exposed part of eye, can be damaged by bacterial and viral species. Each of them has separate characteristics, diagnosis and treatment. They can result in multiple complications so need special attention.