Dysfunction of the meibomian glands (MGD or Meibomian Gland Dysfunction) is caused by the chronic alteration of the sebaceous glands located on the inside of the eyelids. These glands produce oily lipid substances that are released at the edges of the eyelids and reach the tear film thanks to the blinking of the eyelids. The oily lipid substances float on the surface of the tear film and help reduce evaporation. MGD determines an alteration in the lipid component of the tear film and this can result in the appearance of evaporative dry eye with its characteristic symptoms. In more acute cases, MGD can also cause an inflammation of the edges of the eyelid known as posterior blepharitis.
The most important causes of MGD are old age, use of certain medications (e.g. derivatives of retinoic acid used for treating acne; hormone replacement therapy used by women during menopause; antihistamines; antidepressants; anti-androgen medication used for prostatic hypertrophy); endocrine disorders (e.g. menopause; pregnancy), the prolonged use of contact lenses, immune system disorders (e.g. Sjögren syndrome; rheumatoid arthritis; psoriasis; atopic and acne rosacea).
There are different clinical forms of MGD that can be identified based on the appearance of the edges of the eyelids and the characteristics of the sebaceous secretions of the meibomian glands. The most common forms of MGD are latent ones that provoke dry eye symptoms but do not cause any apparent clinical alteration to the edges of the eyelids. Often patients with MGD will complain of irritation and excessive weeping that occur more frequently at night or in the morning, when using the computer or perhaps spending time in excessively overheated and dehumidified environments. Recognising and treating all forms of MGD, and in particular latent ones, allows the dry eye symptoms to be treated more effectively reducing the likelihood that the alterations in the meibomian glands will become irreversible over time.
Treatment of MGD and Dry Eye
Anyone affected by MGD and dry eye can improve their symptoms by changing certain habits and performing eyelid hygiene daily.
It is very useful is to keep domestic and work environments suitably humidified and to avoid excessive use of contact lenses. It is a good idea for anyone using a computer for many hours a day to take regular breaks and deliberately blink their eyelids every now and then to reduce evaporation of the tear film. It has been shown that an increase in the nutritional supply of essential fatty acids ω3 can significantly reduced dry eye symptoms since these substances stimulate the production of the liquid component of the tear film and reduce the formation of inflammation mediators. Following the diet of the western world does not allow for a daily introduction of correct quantities of ω3 fatty acids. Patients affected by MGD should eat foods that are rich in these substances, such as fish, nuts and flaxseeds or to take specific supplements.
Eyelid hygiene is essential in the treatment of MGD because it reduces dry eye symptoms and it can prevent chronically obstructed and inflamed glands from becoming atrophied over time. The three cardinal rules of eyelid hygiene include an increase in the eyelid temperature, expressing glandular secretion and cleaning the edges of the eyelid.
Heat will fluidify sebaceous secretions, which, in patients affected by MGD, thicken and have a higher melting temperature than those of normal subjects. For this purpose, cotton compresses or other materials soaked in hot water (approx. 45°C) are placed on closed eyelids for a few minutes.
Expressing meibomian gland secretion can be performed in different ways, depending on the degree of glandular obstruction. In mild cases, the discharge of the lipid secretions can be encouraged even simply by forcefully and repeatedly blinking the eyelids throughout the day. In other cases, closed eyelids need to be massaged by delicately pressing them with the fingers. These procedures appear to be more effective if carried out after having fluidified the glandular secretion with heat. In extreme cases, when secretion is particularly thick, a doctor will need to express the glands, in order to unclog them.
The cleaning of the glandular orifices and the edge of the eyelids can be performed using medicated wipes or cotton buds. This practice is useful in order to remove any cellular detritus and thickened sebum that may cause the obstruction of the glands and in order to avoid the build up of excessive bacteria and their toxic metabolites. The edges of the eyelids should never be cleaned using surfactants such as soaps or shampoos because these can be responsible for the alteration of the tear film.
Evaporative dry eye caused by MGD is treated with artificial lipid tears, liposomal sprays and gels. Symptoms will recede or disappear only when specific products capable of restoring and stabilising the lipid layer of the tear film are used. In fact, most artificial tears available on the market are not suitable for patients affected by MGD. In general, lipid tears and liposomal sprays are used several times a day depending on the severity of the symptoms, whilst gel formulations are used preferably last thing at night, before going to sleep, because they provoke temporary blurring of the vision. In severe cases, eye drops, sprays and gels can be used together on the same patient and the application frequency can be reduced when the symptoms improve. Correcting bad habits and constant eyelid hygiene reduces the need to frequently use replacement tears. Nevertheless, because evaporative dry eye is almost always a chronic condition, the complete suspension of treatments often leads to a reappearance of the symptoms.
In some patients with MGD, where the inflammation of the eye’s surface and the edges of the eyelids is widespread (blepharitis), it is possible to use cortisone-based ointments or eye drops and antibiotics for limited periods. Even the oral intake of low-dose antibiotics belonging to the tetracycline family reduces inflammation at the edges of the eyelids and improves dry eye symptoms. These antibiotics have a bacteriostatic action on the bacteria present at the edges of the eyelids, but above all they have the capacity to prevent the formation of irritant metabolites that contribute to a worsening of symptoms.
Biodue SpA was founded in 1986 as a corporate structure for the marketing of the PHARCOS dermatological brand. Today, it is an advanced industry in terms of technology for the production of cosmetics, dietary supplements and medical devices.
The BiodueOftalmica ophthalmological line, now called “bOfta”, started in 2007 with a range of specific dietary supplements for each ocular area: Ipolac MGD for the anterior segment, Vitreoial for the intermediate sector, Tauretin-A for the rear sector and Citinerv for the optic nerve.
2009 saw the launch of the first Italian-manufactured periocular spray application for alterations of the tear film: Ipolac Spray.
In May 2010, OFTALDERM, the first line of ophthalmic cosmetics dedicated to “cure” of the periocular area, was created, including wipes and detergent for hygiene and gel for treatment.
In 2013, the line was completed with the ALTIAL tear substitute containing 0.16% hyaluronic acid.
Our goal is to become a reference company for ophthalmology.
More information at: www.biodueoftalmica.it