Rosacea: everything you need to know about the ocular form.

Affecting nearly 415 million people worldwide, the rosacea is a chronic disease characterised particularly by the appearance of continuous and widespread redness on the face. Its symptoms are generally exacerbated by exposure to heat, sunlight, stress or by the consumption of spicy foods.

It is estimated that approximately 30 to 50% of cases of cutaneous rosacea are accompanied by an impact on the eyes. It can also happen that ocular rosacea appears first, causing symptoms in the eyes before affecting the facial skin. Finally, it is also possible to suffer from ocular rosacea alone, without skin symptoms.

Ocular rosacea is an inflammatory condition that presents itself through redness, tearing, itching, and burning sensations. This eye disorder is among the common conditions affecting the surface of the eyes. The eyelids appear swollen, and the eyes are red and dry. They are also particularly sensitive to light. Ocular rosacea also causes the dilation of small blood vessels in the white area of the eye (sclera), making them visible.

Ocular rosacea can develop at any age, however, it is often diagnosed after the age of 30. Statistics also show that women are twice as likely to be affected by rosacea as men, although this phenomenon is not clearly explained.

To date, scientists are still uncertain about the exact causes of rosacea. However, they have observed that the majority of people suffering from ocular rosacea have blocked or malfunctioning sebaceous glands, the Meibomian glands. Located at the base of the eyelids, these glands normally contribute to the lubrication of the eyes by secreting an oily substance. The loss of their function is the cause of the dry eye observed in patients. Moreover, when these glands are blocked, the surrounding area can swell and become irritated. This leads to redness, itching, or feelings of discomfort in the eyes.

There are other hypotheses regarding the origin of ocular rosacea. It is notably suggested that this condition may be caused by the proliferation of mites living in the hair follicles of the face and eyelashes, known as Demodex. Colonisation by these parasites could potentially block the Meibomian glands, leading to their dysfunction. Furthermore, the Demodex secrete proteases, enzymes involved in protein degradation, which stimulate the activity of PAR-2 (Protease-Activated Receptor) receptors present in the epidermis and playing a central role in inflammatory and nociceptive processes. This activation subsequently triggers the release of TNF-α and interleukin-1 (IL-1), inflammatory agents. These agents are responsible for the redness and inflammation of the eyelids observed in individuals suffering from ocular rosacea.

Finally, it could have a genetic origin. Indeed, up to 30% of people suffering from rosacea have a family history of this condition, leading researchers to believe that unidentified genes could be responsible and that, in some cases, it could be a rosacea that is inherited. One hypothesis being considered is the prevalence in people with rosacea of certain receptors involved in inflammatory and nociceptive mechanisms. Moreover, it seems that people with a light phototype are more at risk of being affected by this disorder.

Given that this is a chronic condition, there is no definitive curative treatment. Therefore, it is important to repeat the care procedures described below to alleviate symptoms. The first step is daily eyelid massage to clear the substance accumulated in the Meibomian glands, which is responsible for their blockage. This is sometimes enough to restore their function, leading to the disappearance of inflammation and reducing dry eye. However, in most cases, massages need to be combined with medical treatment. The most common ones are:

• The administration of antibiotics.

  The standard treatment is based on tetracyclines. These antibiotics work by inhibiting the synthesis of proteins by bacteria that are necessary for their growth. This effectively prevents bacterial proliferation. They are effective on most symptoms of ocular rosacea (inflammation around the eyes, conjunctivitis, dry eye), and they also have anti-inflammatory properties and regulate the secretions of the Meibomian glands. In cases where tetracyclines are contraindicated, macrolides, which are antibiotics that inhibit the multiplication of bacteria, are generally used.

• The use of antibiotic eye drops or ointment.

  The application of an antibiotic ointment helps to limit the growth of bacteria on the eyelids. To maximise its effect, it is preferable to combine its application with an eyelid massage. The use of eye drops, on the other hand, reduces ocular inflammation and conjunctivitis.

• Artificial tears.

  The administration of artificial tears helps to alleviate ocular dryness present in almost 100% of patients suffering from rosacea.

As soon as the initial symptoms of ocular rosacea appear, it is crucial to consult an ophthalmologist.

• Thèse de Kelly ZAROUKIAN. Étude des aspects cliniques cellulaires et moléculaires de la rosacée, des traitements dermo-cosmétiques associés ainsi que de l’impact sur la qualité de vie des patients (2017).

• STEINHOFF M. & al. Recent advances in understanding and managing rosacea. F1000 Research (2018).

• SEITZMAN G. & al. Ocular rosacea. Current Opinion in Ophthalmology (2020).

• TAN J. & al. Rosacea: New concepts in classification and treatment. American Journal of Clinical Dermatology (2021).