Conjunctival hyperemia: what is it?

By Cristiano Antonino On May 22, 2023

Conjunctival hyperemia – a medical term for the state of ‘redness of the eye’ – consists precisely of frequent reddening, affecting one or both eyes, due to vasodilation and a consequent increase in the amount of blood circulating

This reddening is usually a symptom of inflammation and – as will be seen below – the triggering causes of conjunctival hyperemia can be many.

The redness may appear alone or may be accompanied by a variety of symptoms affecting the conjunctiva

The latter is the thin membrane that lines the anterior surface of the eyeball – except for the cornea – and the inner surface of the eyelids with the main function of protecting the entire eye from the intrusion of foreign bodies that could alter its balance.

It also facilitates the maintenance of the moist state inside the eye – the lachrymal film – so that the eyelid can slide easily without rubbing damage.

What are the causes of conjunctival hyperemia?

As mentioned, conjunctival hyperemia consists of a visible reddening of the eye, a symptom of vasodilation of the superficial ocular vessels.

This vasodilation and the resulting redness can be caused by:

Dry eye, lack of proper lubrication, rubbing of the eyelid, which, insufficiently lubricated, causes irritation at the level of the conjunctiva.
Eye infections due to bacteria, fungi, viruses or parasites.
Allergies, which may be seasonal (pollen and flowers) or perennial (mites, moulds, pet hair).
Irritation caused by contact with foreign bodies (dust, sand).
Irritation caused by chemical-physical agents (air pollutants, soap, radiation, make-up, cometics).
Abrasions of the cornea itself.
Incorrect or excessively prolonged use of contact lenses.
Excessive consumption of alcohol, which contributes to excessive dilation of superficial blood vessels.
Eye fatigue caused by excessive use of electronic devices (mobile phone, computer, television).
Lack of eye protection in dangerous work environments.
Side effect of certain drugs (anticoagulants).
Alteration of the effectiveness of the tear film due to advancing age.
Acne rosacea.
Rheumatological pathologies (e.g. Sjogren’s syndrome…).

If the state of conjunctival hyperemia is linked to pain, it is necessary to assess the presence of

Uveitis, an inflammation affecting the uveal tract, located between the sclera and the retina.
Iritis, the inflammation of the iris.
Blepharitis, the inflammation of the eyelids.
Keratitis, the inflammation of the cornea.
Scleritis, the inflammation of the sclera.
Acute glaucoma or angle-closure glaucoma.
Trauma that has caused haemorrhage in superficial blood vessels.
Exposure to intense sunlight without the protection of appropriate filters (sunglasses).

Remember, the main cause of conjunctival hyperemia is – trivially – crying, whether irritative or emotional in nature: the conjunctival blood vessels dilate, blood flow increases and the eye becomes red.

Conjunctival hyperemia: symptoms and possible complications

From a medical point of view, ocular hyperemia can occur – due to all the factors listed above – as an autonomous symptom, or in combination with other symptoms, which vary depending on the medical condition presented by the patient.

Symptoms associated with conjunctival hyperemia include blurred vision, photophobia, excessive tearing, a foreign body sensation inside the eye, and mild to intense pain.

If this associated symptomatology lasts only one or two days and then resolves on its own without significant consequences, it is transient conjunctival hyperemia.

If, on the other hand, the disorder does not resolve of its own accord but, on the contrary, worsens to the point of presenting mucous or watery discharge, reduced visual acuity, blurred vision and intense pain in the eyes, then conjunctival hyperemia could be a marker of a more serious disease.

Conjunctivitis

Conjunctivitis consists of inflammation of the conjunctiva, which leads to the appearance of conjunctival hyperemia, i.e. widespread redness of the entire eye, excluding the iris part.

Hyperemia in this case may be accompanied by symptoms such as itching, burning, blurred vision and hypersensitivity to light; as well as secretions and crusts along the eyelash rima due to which the eye tends to ‘stick’.

Foreign body inside the eye

The presence of a foreign body inside the eye causes – predictably – symptoms only in the affected eye, which presents with diffuse conjunctival hyperemia, pain, difficulty in keeping the eye open, lacrimation, hypersensitivity to light.

The foreign body must be promptly removed in order to prevent it from damaging the corneal surface.

Allergy

Allergies include conjunctival hyperemia among their most common symptoms.

This can be caused by environmental agents such as pollen, dust mites, mould, pet hair; or it could be a local contact allergy caused by soaps, cosmetics, make-up that come into direct contact with the conjunctiva.

Glaucoma

If conjunctival hyperemia is accompanied by severe itching, this could be a symptom of a sudden increase in intraocular pressure leading to the development of glaucoma.

If this were the case, it would be a very serious condition that should be immediately referred to a specialist ophthalmologist.

How to diagnose conjunctival hyperemia

If, as anticipated, conjunctival hyperemia regresses spontaneously, there is no need to contact a specialist quickly.

On the contrary, if conjunctival hyperaemia does not regress but even seems to worsen, it is certainly advisable to contact the ophthalmologist for an urgent examination.

The ophthalmologist, after taking an accurate anamnesis, will examine the patient to identify the cause of conjunctival hyperaemia, make a correct diagnosis and then prescribe the most appropriate therapy.

Conjunctival hyperemia: the most correct therapy and how to prevent its recurrence

Since conjunctival hyperemia is a symptom common to many, even profoundly different pathologies, the therapy is not unique, but is aimed at the pathology in progress, thus also resolving the hyperemia.

In general, the ophthalmologist can use drug therapy based on antibiotics or anti-inflammatories and antihistamines in the form of eye drops or ointment, artificial tears and disinfectant solutions for the ocular surface and adnexa.

To prevent conjunctival hyperemia from recurring, the ophthalmologist will advise the patient to avoid frequenting places characterised by environmental pollution, to always use a humidifier if the environment is excessively dry, and to always wash their hands thoroughly, which, as is well known, are the first vehicle for germs and bacteria that could find a breeding ground in the eye.

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