**2. Infectious conjunctivitis**

Infective conjunctivitis can be caused by several bacterial and viral pathogens. Infective con‐ junctivitis can be further differentiated into acute infective conjunctivitis, defined as inflam‐ mation of the conjunctiva due to infection that does not last longer than 3 weeks, and chronic conjunctivitis, inflammation of the conjunctiva that lasts longer than 3 weeks.

In the developed world, acute infectious conjunctivitis is a common presentation in the pri‐ mary care setting, accounting for up to 2% of consultations with the general practitioner [ 2]. Many general practitioners find it difficult to differentiate between bacterial and viral con‐ junctivitis. The uncertainty of the pathogenic cause of acute conjunctivitis has led to the rou‐ tine practice of prescribing a broad spectrum antibiotic topically even though the pathogen has not been proved to be bacterial in nature. In the UK, approximately 3.4 million topical antibiotic prescriptions are issued every year, at a cost to the NHS of over £4.7 million [3].

A diagnosis of conjunctivitis is usually made on the basis of a clinical history and examina‐ tion by the clinician. Other investigations of conjunctivitis, such as swabs and cultures of the conjunctiva are rarely performed as it often delays treatment and has very little prognostic benefit, as conjunctivitis is often a self limiting illness and the antibiotics currently used have a good spectrum of pathogen coverage. Swabs and cultures are mainly used in research pur‐ poses.

It is vital that a correct diagnosis is made to early to identify the cause and start treatment promptly. It is also essential to rule out more serious causes and medical emergencies that would require hospital admission. Such cases would include bacterial keratitis, acute closed angle glaucoma, corneal abrasions and others.

#### **2.1. Bacterial conjunctivitis**

Bacterial conjunctivitis is a relatively common infection and affects all people, although a higher incidence is seen in infants, school children and the elderly. Bacterial conjunctivitis has a higher prevalence in children, where a recent study by Rose et al identified 67% of 326 children as having a bacterial cause [4]. Although its incidence is continuing to decrease in developing nations, periodic rises in incidence are seen during the monsoon seasons in many countries such as Bangladesh, and thus, bacterial conjunctivitis is the most common cause of infective conjunctivitis in developing nations.

#### *2.1.1. Types of bacterial conjunctivitis and pathogenic causes of bacterial conjunctivitis*

Bacterial conjunctivitis can be broadly split into three major categories; hyperacute bacterial conjunctivitis, acute conjuncitivis and chronic conjunctivitis.

**•** Hyperacute bacterial conjunctivitis is commonly seen in patients affected with *N. Gonor‐ rhoea*. The onset is often rapid with an exaggerated form of conjunctival injection, chemosis and copious purulent discharge. Prompt treatment is essential to prevent complications.


In certain bacterial conjunctivitis, it is essential to identify a pathogen. As mentioned, most causes of conjunctivitis are diagnosed and treated on a clinical exam basis, but in patients who are particularly susceptible such as neonates or immunodeficient patients, a microbio‐ logical diagnosis must be made to exclude harmful pathogens such as *N.gonorrheae*, *Listeria monocytogenes*, *Corynobacterium diptheriae* and certain members of the *Haemophilus* group. These pathogens contain proteolytic enzymes which may cause long term damage to the pa‐ renchyma of the conjunctiva.

#### *2.1.2. Signs and symptoms of bacterial conjunctivitis*

**2. Infectious conjunctivitis**

24 Common Eye Infections

angle glaucoma, corneal abrasions and others.

cause of infective conjunctivitis in developing nations.

conjunctivitis, acute conjuncitivis and chronic conjunctivitis.

**2.1. Bacterial conjunctivitis**

poses.

Infective conjunctivitis can be caused by several bacterial and viral pathogens. Infective con‐ junctivitis can be further differentiated into acute infective conjunctivitis, defined as inflam‐ mation of the conjunctiva due to infection that does not last longer than 3 weeks, and

In the developed world, acute infectious conjunctivitis is a common presentation in the pri‐ mary care setting, accounting for up to 2% of consultations with the general practitioner [ 2]. Many general practitioners find it difficult to differentiate between bacterial and viral con‐ junctivitis. The uncertainty of the pathogenic cause of acute conjunctivitis has led to the rou‐ tine practice of prescribing a broad spectrum antibiotic topically even though the pathogen has not been proved to be bacterial in nature. In the UK, approximately 3.4 million topical antibiotic prescriptions are issued every year, at a cost to the NHS of over £4.7 million [3].

A diagnosis of conjunctivitis is usually made on the basis of a clinical history and examina‐ tion by the clinician. Other investigations of conjunctivitis, such as swabs and cultures of the conjunctiva are rarely performed as it often delays treatment and has very little prognostic benefit, as conjunctivitis is often a self limiting illness and the antibiotics currently used have a good spectrum of pathogen coverage. Swabs and cultures are mainly used in research pur‐

It is vital that a correct diagnosis is made to early to identify the cause and start treatment promptly. It is also essential to rule out more serious causes and medical emergencies that would require hospital admission. Such cases would include bacterial keratitis, acute closed

Bacterial conjunctivitis is a relatively common infection and affects all people, although a higher incidence is seen in infants, school children and the elderly. Bacterial conjunctivitis has a higher prevalence in children, where a recent study by Rose et al identified 67% of 326 children as having a bacterial cause [4]. Although its incidence is continuing to decrease in developing nations, periodic rises in incidence are seen during the monsoon seasons in many countries such as Bangladesh, and thus, bacterial conjunctivitis is the most common

Bacterial conjunctivitis can be broadly split into three major categories; hyperacute bacterial

**•** Hyperacute bacterial conjunctivitis is commonly seen in patients affected with *N. Gonor‐ rhoea*. The onset is often rapid with an exaggerated form of conjunctival injection, chemosis and copious purulent discharge. Prompt treatment is essential to prevent complications.

*2.1.1. Types of bacterial conjunctivitis and pathogenic causes of bacterial conjunctivitis*

chronic conjunctivitis, inflammation of the conjunctiva that lasts longer than 3 weeks.

Although the symptoms of bacterial conjunctivitis are varied and quite vast, there are a number of key symptoms which differentiate it from other eye infections. Thick purulent discharge is seen as the major symptom that affects sufferers of bacterial conjunctivitis, com‐ pared to the watery discharge seen in viral conjunctivitis. This leads to 'glue eye' which is often the term used to describe difficulty opening the eye due to thick sticky secretions. A study done in 2004 in the Netherlands confirmed that 'early morning glue eye' was a posi‐ tive predictor of bacterial conjunctivitis amongst 184 patients presenting with 'glue eye', itch or a past history of conjunctivitis [8].

**Figure 5.** Mucopurulent discharge seen in bacterial conjunctivitis

**Figure 6.** Injection of the conjunctiva and chemosis are two common symptoms and are demonstrated here

Other symptoms which are commonly seen in bacterial conjunctivitis is a 'foreign body' sen‐ sation, injection of the conjunctiva, chemosis (conjunctival oedema), itching, erythema of the eyelid skin and some patients also experience a slight burning or stinging sensation. In stud‐ ies done by Carr et al and Wall et al almost all patients presented with injection of the con‐ junctiva, up to 90% of patients with bacterial conjunctivitis presented with itching and a foreign body sensation and up to 50% of patients presented with a burning or stinging sen‐ sation [9, 10]. Erythema of the eyelid was seen in 85% of patients.

#### *2.1.3. Complications of bacterial conjunctivitis*

Bacterial keratitis is a well known but rare complication of bacterial conjunctivitis [11]. Peo‐ ple at particularly high risk of developing keratitis often have corneal epithelial defects or disease and patients who have particularly dry eyes are seen to be at an increased risk.

#### *2.1.4. Treatment of bacterial conjunctivitis*

Bacterial conjunctivitis is commonly treated empirically with broad-spectrum antibiotics. Broad-spectrum antibiotics that have good efficacy against both gram-negative and grampositive are necessary as a diverse range of pathogens can be the cause of infections. A Co‐ chrane systematic review found that acute bacterial conjunctivitis is often a self-limiting condition, 65% (95% confidence interval of 59% to 70%) patients treated with placebo showed significant improvement occurring by the second to fifth day of infection [12]. Pa‐ tients treated with topical antibiotics were shown to have improved clinical outcome, espe‐ cially when treated early (days 2 to 5) with relative risk = 1.24, 95% confidence interval = 1.05 to 1.45. Patients treated late (days 7 to 10) had reduced clinical benefit with relative risk = 1.11, 95% confidence interval = 1.02 to 1.21. Microbiological remission was also improved with treatment, early (days 2 to 5) showing relative risk = 1.77, 95% confidence interval = 1.23 to 2.54 and late (days 7 to 10) relative risk = 1.56, 95% confidence interval= 1.17 to 2.09.

An open, randomized and controlled study by Everitt et al investigated 307 adults and chil‐ dren with suspected infective conjunctivitis using three different treatment methods: no treatment, delayed topical treatment and immediate topical chloramphenicol treatment [13]. The varying treatments did not affect the severity of symptoms experienced within the first three days of infection. However, patients with moderate symptoms who were treated im‐ mediately with topical chloramphenicol had a reduced duration of symptoms with an aver‐ age of 3.3 days whilst patients that received no treatment had 4.9 days duration.

Rietveld et al carried out a double-blind randomized and placebo controlled study in a pri‐ mary care setting. The efficacy of fusidic acid gel was compared to a placebo gel in 163 adult patients presenting with a red eye and mucopurulent discharge [14]. After 7 days the treat‐ ments were evaluated with clinical cure being found in 62% of patients on fusidic acid gel and 59% of patients on placebo gel. The study found that the severity of symptoms and the duration of symptoms were not significantly different in either group. In conclusion, with the limited evidence the authors produced, they did not support the current practice of pre‐ scribing empirical antibiotics.

**Figure 6.** Injection of the conjunctiva and chemosis are two common symptoms and are demonstrated here

sation [9, 10]. Erythema of the eyelid was seen in 85% of patients.

*2.1.3. Complications of bacterial conjunctivitis*

26 Common Eye Infections

*2.1.4. Treatment of bacterial conjunctivitis*

Other symptoms which are commonly seen in bacterial conjunctivitis is a 'foreign body' sen‐ sation, injection of the conjunctiva, chemosis (conjunctival oedema), itching, erythema of the eyelid skin and some patients also experience a slight burning or stinging sensation. In stud‐ ies done by Carr et al and Wall et al almost all patients presented with injection of the con‐ junctiva, up to 90% of patients with bacterial conjunctivitis presented with itching and a foreign body sensation and up to 50% of patients presented with a burning or stinging sen‐

Bacterial keratitis is a well known but rare complication of bacterial conjunctivitis [11]. Peo‐ ple at particularly high risk of developing keratitis often have corneal epithelial defects or disease and patients who have particularly dry eyes are seen to be at an increased risk.

Bacterial conjunctivitis is commonly treated empirically with broad-spectrum antibiotics. Broad-spectrum antibiotics that have good efficacy against both gram-negative and grampositive are necessary as a diverse range of pathogens can be the cause of infections. A Co‐ chrane systematic review found that acute bacterial conjunctivitis is often a self-limiting condition, 65% (95% confidence interval of 59% to 70%) patients treated with placebo showed significant improvement occurring by the second to fifth day of infection [12]. Pa‐ tients treated with topical antibiotics were shown to have improved clinical outcome, espe‐ cially when treated early (days 2 to 5) with relative risk = 1.24, 95% confidence interval = 1.05 to 1.45. Patients treated late (days 7 to 10) had reduced clinical benefit with relative risk = 1.11, 95% confidence interval = 1.02 to 1.21. Microbiological remission was also improved with treatment, early (days 2 to 5) showing relative risk = 1.77, 95% confidence interval = 1.23 to 2.54 and late (days 7 to 10) relative risk = 1.56, 95% confidence interval= 1.17 to 2.09.

The majority of doctors actively treat uncomplicated acute bacterial conjunctivitis with em‐ pirical topical antibiotics at diagnosis. There are several other options available including: delaying treatment for 5 days and begin treatment if no sign of improvement and to treat patients who have clinical features associated with a bacterial cause. Studies comparing the effectiveness of different antibiotics recommended for use in suspected bacterial conjunctivi‐ tis have shown similar levels of effectiveness. Therefore, it is important to consider local bac‐ terial resistance and cost-effectiveness of the antibiotics being prescribed [15]. All antibiotic courses should be taken for 7-10 days. Compliance with the length of time the antibioticsare prescribed for is particularly important to help prevent resistance developing.

The first line treatment in mild to moderate bacterial conjunctivitis is either Trimethoprim-Pol‐ ymyxin B (Polytrim) solution, Erythromycin 0.5% ointment, or Azithromycin drops. Alterna‐ tives to these antibiotics are bacitracin ointment and sulfacetamide drops. In moderate to severe infections, or antibiotic-resistant infections and in immunocompromised patients, fluo‐ roquinolones are recommended. These include: ofloxacin, ciprofloxacin, levofloxacin, moxi‐ floxacin and gatifloxacin. Chlamydial conjunctivitis requires oral antibiotics alongside a topical antibiotic to treat the systemic infection alongside the ophthalmic manifestation. The oral antibiotic options include Azithromycin, doxycycline, or erythromycin. These are given in combination with Azithromycin or erythromycin drops for 2 to 3 weeks [16]. In addition, pa‐ tients should be advised to take several precautions to help prevent spread of infection. Pa‐ tients should wash their hands regularly and thoroughly, especially after touching any infected secretions. Furthermore, patients should avoid sharing towels, pillows, or utensils.

Studies have shown that treatment with topical antibiotics shortens the duration of disease, prevents spread of infection, reduces the rate of recurrence, and decreases the risk of com‐ plications that effect vision [17].However, there has been controversy in recent years over the use of empirical antibiotics and its role in an evidently self-limiting disease with the clin‐ ical outcome being only marginally favourable to taking no antibiotics. There has been in‐ creasing antibiotic resistance especially among the older class of antibiotics that have been used extensively such as chloramphenicol, sulphonamides, polymyxins, bacitracin, amino‐ glycosides and early generation fluoroquinolones. The efficacy of these drugs has reduced to a combination of resistance and narrow spectrum of activity [18, 19].The newer genera‐ tion of fluoroquinolones, such as gatifloxacin and moxifloxacin, have a greater range of ac‐ tivity and efficacy against common pathogens of the eye [20].Specifically, they have better *in vitro* efficacy over the older generation fluoroquinolones against gram positive pathogens. However, the efficacy was not greater with *Haemophilus influenza* isolates [21]. The Ocular Tracking Resistance in the U.S. Today (TRUST) initiative annually monitors the *in vitro* sus‐ ceptibility of common ocular pathogens; Staphylococcus aureus, Streptococcus pneumonia, and Haemophilus influenzae. Between 2000 and 2005 there was a 12.1% increase in the inci‐ dence of methicillin-resistant Staphylococcus aureus (MRSA). Moreover, greater than 80% of the MRSA strains were also resistant to fluoroquinolones [22, 23].

#### *2.1.5. Prognosis of bacterial conjunctivitis*

The prognosis of bacterial conjunctivitis is normally very good with the correct and prompt treatment of the infection. In many cases, spontaneous remission, without a cure, is seen. In a study done by Sheikh and Hurwitz et al, spontaneous cure occurred in 60% of patients within 1-2 weeks [24]. However, with prompt antibiotic treatment, the treatment time is sig‐ nificantly reduced.

#### **2.2. Viral conjunctivitis**

Viral conjunctivitis is a common infection amongst the Western population, and is often as‐ sociated with other infections around the body. Due to the contiguity with the respiratory tract anatomy, viral upper respiratory tract infections are a common cause of secondary vi‐ ral conjunctivitis.

Most cases of viral conjunctivitis are mild. Days 3-5 of infection are often the worst, but the infection will usually clear up in 7–14 days without treatment and without any long-term consequences. In some cases, viral conjunctivitis can take 2-3 weeks or more to clear up, es‐ pecially if complications arise.

#### *2.2.1. Pathogens causing viral conjunctivitis*

Much unlike bacterial conjunctivitis, there are many pathogens associated with viral con‐ junctivitis, although the majority of cases of viral conjunctivitis are encompassed by a few common pathogens. The specific viruses are much dependant on the geographical area in the world. In a study done in the Far East countries of Japan, Korea and Taiwan the most common pathogens isolated from 1105 cases were *adenovirus 8* and *enterovirus 70*. Other vi‐ ruses also identified were *adenoviruses 19* and *37* [25]. Similarly, the causes of viral conjuncti‐ vitis in the Western countries are mainly *adenoviruses*, though *adenovirus 13* seems to be the dominant strain in these countries.

Other rarer causes of viral conjunctivitis include *herpes simplex* virus, *herpes zoster* virus and the *measles* virus. Although less commonly seen, it is essential to identify *herpes* and *measles* viruses early to ensure prompt treatment, to prevent any long term complications associated with these viruses.

A recent study also showed outbreaks of the *avian influenza* viruses in patients, although this may possibly be linked to the recent outbreaks of the virus in humans.

#### *2.2.2. Signs and symptoms of viral conjunctivitis*

used extensively such as chloramphenicol, sulphonamides, polymyxins, bacitracin, amino‐ glycosides and early generation fluoroquinolones. The efficacy of these drugs has reduced to a combination of resistance and narrow spectrum of activity [18, 19].The newer genera‐ tion of fluoroquinolones, such as gatifloxacin and moxifloxacin, have a greater range of ac‐ tivity and efficacy against common pathogens of the eye [20].Specifically, they have better *in vitro* efficacy over the older generation fluoroquinolones against gram positive pathogens. However, the efficacy was not greater with *Haemophilus influenza* isolates [21]. The Ocular Tracking Resistance in the U.S. Today (TRUST) initiative annually monitors the *in vitro* sus‐ ceptibility of common ocular pathogens; Staphylococcus aureus, Streptococcus pneumonia, and Haemophilus influenzae. Between 2000 and 2005 there was a 12.1% increase in the inci‐ dence of methicillin-resistant Staphylococcus aureus (MRSA). Moreover, greater than 80% of

The prognosis of bacterial conjunctivitis is normally very good with the correct and prompt treatment of the infection. In many cases, spontaneous remission, without a cure, is seen. In a study done by Sheikh and Hurwitz et al, spontaneous cure occurred in 60% of patients within 1-2 weeks [24]. However, with prompt antibiotic treatment, the treatment time is sig‐

Viral conjunctivitis is a common infection amongst the Western population, and is often as‐ sociated with other infections around the body. Due to the contiguity with the respiratory tract anatomy, viral upper respiratory tract infections are a common cause of secondary vi‐

Most cases of viral conjunctivitis are mild. Days 3-5 of infection are often the worst, but the infection will usually clear up in 7–14 days without treatment and without any long-term consequences. In some cases, viral conjunctivitis can take 2-3 weeks or more to clear up, es‐

Much unlike bacterial conjunctivitis, there are many pathogens associated with viral con‐ junctivitis, although the majority of cases of viral conjunctivitis are encompassed by a few common pathogens. The specific viruses are much dependant on the geographical area in the world. In a study done in the Far East countries of Japan, Korea and Taiwan the most common pathogens isolated from 1105 cases were *adenovirus 8* and *enterovirus 70*. Other vi‐ ruses also identified were *adenoviruses 19* and *37* [25]. Similarly, the causes of viral conjuncti‐ vitis in the Western countries are mainly *adenoviruses*, though *adenovirus 13* seems to be the

Other rarer causes of viral conjunctivitis include *herpes simplex* virus, *herpes zoster* virus and the *measles* virus. Although less commonly seen, it is essential to identify *herpes* and *measles*

the MRSA strains were also resistant to fluoroquinolones [22, 23].

*2.1.5. Prognosis of bacterial conjunctivitis*

nificantly reduced.

28 Common Eye Infections

ral conjunctivitis.

**2.2. Viral conjunctivitis**

pecially if complications arise.

*2.2.1. Pathogens causing viral conjunctivitis*

dominant strain in these countries.

As with bacterial conjunctivitis, a diagnosis of viral conjunctivitis is often made by the gen‐ eral practitioner on the basis of a history and examination. However, due to the overlap in symptoms between viral and bacterial conjunctivitis, it is often difficult to ascertain viral from bacterial conjunctivitis.

**Figure 7.** Classical 'pink' eye associated with conjunctival injection seen in viral conjunctivitis

**Figure 8.** Classical follicles seen in the conjunctiva in a patient suffering from herpetic conjunctivitis

The key symptom of viral conjunctivitis is 'pink eye'. This shows a fine, diffuse pinkness of the conjunctiva, which is often easily mistaken for the ciliary injection of iritis. Other symp‐ toms associated with viral conjunctivitis include discharge which is often clear and watery. This is often the most discernible difference between bacterial and viral conjunctivitis.

A history of itchy eyes is also suggestive of viral conjunctivitis, although it is a symptom al‐ so associated with irritant and allergic conjunctivitis. Rarer symptoms associated with sim‐ ple *adenovirus* viral conjunctivitis include foreign body sensation, ocular discomfort, excessive tearing and sticky eyelids which are worse in the morning.

*Herpes simplex* conjunctivitis is usually unilateral. Symptoms include a red eye, photophobia, eye pain and mucoid discharge. There may be periorbital vesicles, and a conjunctival branching (dendritic) pattern of fluorescein staining makes the diagnosis.

Below is a table summarising the key differences between adenoviral and herpetic viral con‐ junctivitis.


**Table 1.** A summary of the differences of adenoviral and herpetic viral conjunctivitis

Herpes zoster Ophthalmicus is shingles of the opthalmic branch of the trigeminal nerve, which innervates the cornea and the tip of the nose. It begins with unilateral neuralgia, fol‐ lowed by a vesicular rash in the distribution of nerve. Once spread to the eye, it may lead to an extremely painful conjunctivitis and may take several days to settle.

#### *2.2.3. Complications of viral conjunctivitis*

There are many recognised complications of viral conjunctivitis. In many cases, it may be associated with inflammation of the cornea, known as keratoconjunctivitis. There is also an increase in likelihood of a superimposed bacterial infection. Other rare complications associ‐ ated with viral conjunctivitis include blepharitis, entropion and in very rare cases, scarring of the eyelid.

**Figure 9.** Herpes simplex keratitis, demonstrated here via fluorescein staining

The most serious complication of viral conjunctivitis is *herpes simplex* keratitis, a corneal ul‐ cer, which can ultimately lead to blindness. This is an extremely rare side effect of viral con‐ junctivitis and requires immediate transfer to hospital and review by the ophthalmologists.

#### *2.2.4. Treatment of viral conjunctivitis*

The key symptom of viral conjunctivitis is 'pink eye'. This shows a fine, diffuse pinkness of the conjunctiva, which is often easily mistaken for the ciliary injection of iritis. Other symp‐ toms associated with viral conjunctivitis include discharge which is often clear and watery.

A history of itchy eyes is also suggestive of viral conjunctivitis, although it is a symptom al‐ so associated with irritant and allergic conjunctivitis. Rarer symptoms associated with sim‐ ple *adenovirus* viral conjunctivitis include foreign body sensation, ocular discomfort,

*Herpes simplex* conjunctivitis is usually unilateral. Symptoms include a red eye, photophobia, eye pain and mucoid discharge. There may be periorbital vesicles, and a conjunctival

Below is a table summarising the key differences between adenoviral and herpetic viral con‐

This is often the most discernible difference between bacterial and viral conjunctivitis.

excessive tearing and sticky eyelids which are worse in the morning.

**Adenoviral Herpetic**

Punctate keratitis Follicles

*2.2.3. Complications of viral conjunctivitis*

of the eyelid.

Hyperaemia Diffuse hyperaemia

junctivitis.

30 Common Eye Infections

branching (dendritic) pattern of fluorescein staining makes the diagnosis.

Watery discharge bilaterally Usually unilateral watery discharge

Preauricular and/or submandibular lymphadenopathy Occasional preauricularlypmphadenopathy

Associated with pharyngitis Major complication of dendritic epethilial keratitis

Herpes zoster Ophthalmicus is shingles of the opthalmic branch of the trigeminal nerve, which innervates the cornea and the tip of the nose. It begins with unilateral neuralgia, fol‐ lowed by a vesicular rash in the distribution of nerve. Once spread to the eye, it may lead to

There are many recognised complications of viral conjunctivitis. In many cases, it may be associated with inflammation of the cornea, known as keratoconjunctivitis. There is also an increase in likelihood of a superimposed bacterial infection. Other rare complications associ‐ ated with viral conjunctivitis include blepharitis, entropion and in very rare cases, scarring

Petechial hemorrhages Vesicular eruptions on eyelid

Serous, mucoid, or mucopurulent discharge Serous mucoid discharge

**Table 1.** A summary of the differences of adenoviral and herpetic viral conjunctivitis

an extremely painful conjunctivitis and may take several days to settle.

Viral conjunctivitis is a self-limiting disease that usually resolves within two weeks of onset of symptoms and does not require treatment with antiviral medication. There is no evidence sup‐ porting the use of anti-viral medication and their efficacy has not been proven. However, as a highly contagious disease, there is a need to make infected patients aware of good hygiene practices to prevent further spread. Viral conjunctivitis is transmitted through direct contact, therefore, hands should be thoroughly washed regularly, and infected patients should not share pillows, towels and other utensils [26].The highly contagious nature of viral conjunctivi‐ tis, especially adenovirus, makes it necessary for infected patients to avoid going to work or school for 5 days to 2 weeks. Contagiousness of adenovirus conjunctivitis has been shown to be reduced in an *in vitro* study using the topical anti-viral agent povidone-iodine. Povidone-io‐ dine at a concentration of 1:10 (0.8%) is particularly effective against free adenovirus, eradicat‐ ing all of them within 10 minutes with little cytotoxicity [27]. In addition, patients with contact lenses should avoid using them until the conjunctivitis resolves and last dose of any treatment having been taken over 24 hours ago [28]. Treatment for viral conjunctivitis is supportive, in‐ volving cold compresses, ocular decongestants, and artificial tears for symptomatic relief. In patients with high susceptibility of contracting bacterial infections an antibiotic may be given to prevent a bacterial superinfection occurring.If a pseudomembrane or corneal subepithelial infiltrates develop then a topical corticosteroid may be given alongside the other non-pharma‐ cological treatments outlined earlier. Immediate referral to an ophthalmologist should be con‐ sidered in patients with a psuedomembrane or corneal subepithelial infiltrate. Immediate referral is necessary in patients with hyperacute conjunctivitis or those who have corneal in‐ volvement including ulceration and herpetic keratitis.

#### *2.2.5. Prognosis of viral conjunctivitis*

Viral conjunctivitis is extremely contagious and remains so for 14 days, which also is often how long the symptoms remain.

The prognosis is very good for viral conjunctivitis. It resolves completely within 2 weeks of the 'pink eye' onset and there are rarely any long term complications or problems associated with viral conjunctivitis [29].
