Retinol is an ingredient in many anti-acne and anti-aging products. Is there is a link between retinol and dry eye?
What is retinol?
Retinol is a type of retinoid, which is a family of vitamin A derivatives. Retinol and other retinoids are often found in anti-acne and anti-aging products. We hear the most about retinol (retinol is the lead singer of the retinoid band), but our conversation today will encompass all retinoids.
There are over-the-counter forms of retinoids as well as prescriptions forms. You can scan the ingredients list on your products and look for some common retinoids (1):
- (i) first generation, which includes alitretinoin (9-cis-retinoic acid), retinaldehyde, retinol, isotretinoin (13-cis-retinoic acid aka Accutane), tretinoin (trans-retinoic acid)
- (ii) second generation, whose representatives are acitretin and etretinate
- (iii) third generation, which includes adapalene (aka Differin), arotinoid, arotinoid ethyl, methyl sulfone arotynoid, bexarotene, tazarotene
How do retinoids affect the skin?
Retinoids are believed to reduce hyperpigmentation and roughness by enhancing skin cell turnover, thus improving skin’s tone and texture. Retinoids also reduce fine lines and wrinkles by stimulating glycosaminoglycan and collagen production and inhibiting enzymes that degrade collagen (2, 3, 4). In beauty-speak, retinoids can help even skin tone, improve skin texture, and reduce fine lines and wrinkles. Sign me up, right? Not so fast…
How do retinoids affect the eyes?
Vitamin A can be beneficial to some tissues of the eye, but it can be detrimental to others. The meibomian glands, for instance, do NOT like vitamin A.
Meibomian glands, located in the upper and lower eyelid, secrete lipids or oils that become part of the tear film. This helps prevent dryness, as the oils keep tears from evaporating too quickly. These oils play a vital role in stabilizing the tear film, and a stable tear film in turn provides a clear optical surface for good vision. Meibomian gland secretions also interfere with bacterial colonization and retard tear overflow.
Accutane, or isoretinoin, is an oral retinoid that is used for acne treatment because it decreases the growth, development, and lipid production of sebaceous gland epithelial cells. Meibomian glands are large sebaceous glands, so it makes sense that they would be damaged as well. Indeed, that is the case. The theory is that isoretinoin inhibits cell growth, increases cell death, alters gene expression, promotes inflammatory mediator and protease expression in meibomian gland epithelial cells (5). I have seen several patients with significant meibomian gland loss that was likely at least in part due to Accutane use in the past.
In a study using human meibomian gland cell culture (HMGC), isoretinoin was found to significantly increase the expression of a variety of genes encoding inflammatory mediators as well as genes associated with cell death, while also decreasing the expression of genes related to proliferation (5). Isoretinoin can lead to ductal keratinization and obstruction, gland atrophy, gland drop out, and poor quality of meibomian gland secretions (5).
Translation? Isoretinoin alters the structure and function of the meibomian glands, promoting meibomian gland dysfunction and evaporative dry eye (6). This was found to be the case in even low concentrations of isoretinoin (7).
So what’s the take-away?
What may be beneficial to the skin of the face may be detrimental to the oil glands of the eyelids, causing gland loss and dryness. I would recommend using products that do not have vitamin A derivatives around the eye. If you are using a product with any type of retinoid, avoid applying the product to the eyelids to reduce the risk of damaging the meibomian glands.
| CLIFFSNOTES: Retinoic acid derivatives promote meibomian gland dysfunction, a leading cause of dry eye disease. If you use products that contain retinoids, be sure to avoid applying them to the eyelid area. |