(I-MED Pharma)
Did you know that Dry Eye Disease (DED) is not as simple as just a lack of moisture? In fact, the condition is characterized based on how its causes impact the surface of your eye, including the protective layer of tears that covers it[1].
DED is classified as one of two types, or a combination of both[2]. These types include Aqueous Deficient Dry Eye (ADDE) and Evaporative Dry Eye (EDE), with the combination of the two referred to as Mixed Dry Eye (MDE). This article will explore the difference between these forms of dry eye and why knowing the difference matters when it comes to effective diagnosis and management.
Aqueous Deficient Dry Eye
Aqueous Deficient Dry Eye (ADDE) occurs when your eyes don’t produce enough tears. ADDE has a number of risk factors, with the two major ones being aging and Sjögren’s disease.
As we age, the function of our tear-producing glands (lacrimal glands) decreases, meaning that we naturally produce fewer tears. However, with modern lifestyles that entail a high amount of screen time both at work and at play, younger people are also increasingly at risk for DED.
Sjögren’s disease is an autoimmune condition that, among other things, also impacts the ability of the lacrimal glands to do their job. Sjögren’s becomes more common with age and is overrepresented in women[3] While up to an estimated 90% of patients with Sjögren’s suffer from ADDE, DED is also common in those who suffer from other autoimmune disorders, like rheumatoid arthritis and lupus, as well as certain other conditions like thyroid disease and inflammatory bowel disease[4].
This condition can cause a range of discomforting symptoms, including burning, stinging, red or watery eyes, and a gritty feeling or foreign body sensation, as well as not being able to produce tears when crying[5].
Distinguishing between the two forms of DED may not always be so cut-and-dried[6], but distinguishing ADDE from its counterpart, EDE, helps ensure that you receive the right care for your situation. So then, what exactly is EDE?
Evaporative Dry Eye
Evaporative Dry Eye (EDE) occurs when your eyes produce low-quality tears. Your eyes are covered by a thin layer called the tear film that’s made up of three parts:
The main culprit in EDE is meibomian gland dysfunction (MGD), which affects the lipid layer. When the lipid-producing glands in the eyelids, the meibomian glands, don’t function at capacity, the lipid layer can’t properly prevent tears from evaporating, so they evaporate too quickly[8]. Evaporation contributes to the tear film thinning between blinks[9], and this ongoing loss of moisture then disrupts the tear film, leading to discomforting symptoms like those of ADDE.
EDE is more common than ADDE, and many people experience both types to different extents. MGD is not synonymous with EDE, which can also be caused by such things as excessive screen use and environmental factors like seasonal weather conditions. However, roughly 85% of dry eye patients experience MGD[10], [11].
Meibomian Gland Dysfunction (MGD)
MGD can be caused by a variety of factors, including skin conditions such as rosacea, contact lens use, and the simple fact that the glands lose function as we age[12], [13] It can also be caused by, and can cause, inflammation of the lid margin, known as blepharitis[14]. Accutane (isotretinoin) has also been implicated as a cause of MGD[15].
There is strong overlap between the symptoms of MGD and DED, with key symptoms including burning, irritation, and foreign body sensation[16], as well as red and swollen eyes. Fortunately, there are many possibilities for managing symptoms, although it remains difficult to relieve them completely, and the body of research on the reversibility of meibomian gland atrophy is still inconclusive[17], [18]. That said, certain treatment options exist for MGD, including IRPL® treatment with the E>Eye device. This is an in-clinic treatment that uses Intense Regulated Pulsed Light to stimulate the meibomian glands to improve their function.
Getting a Diagnosis
Dry Eye Disease is a condition that warrants care, not just because it is often accompanied by varying degrees of discomfort, but also because, in the long term, it can potentially damage the eyes and impact vision.
To diagnose DED, your eye care professional will conduct a series of tests to measure factors like the salt concentration of your tears (tear osmolarity). They may also set you up with a management plan to ensure your eyes stay clean, hydrated, and healthy.
Management and Prevention Strategies
For both ADDE and EDE, the first line of defence is often eye drops for dry eyes. Preservative-free artificial tears, like our I-DROP® line, help hydrate and lubricate the cornea while reducing tear film evaporation. I-DROP® MGD is specifically formulated for those with chronic, evaporative DED. Containing superior osmoprotectants and bioprotectants, it helps to stabilize and enhance the lipid layer while reducing evaporation of the tear film.
Eyelid hygiene is also an important part of dry eye management. Daily use of an ocular hygiene cleanser like the I-LID ’N LASH® product line helps remove debris, reduce bioburden, and increase the effectiveness of artificial tears.
To relieve dry eye symptoms like red, swollen eyelids, blurred vision, and gritty, itchy, or burning sensations, moist heat therapy may be useful, particularly for those who suffer from MGD. An eye mask for dry eyes can be a great help. For example, the I-RELIEF™ Hot & Cold Therapy Eye Mask with ThermaBeads™ provides moist heat therapy, as well as cold therapy, which constricts the blood vessels to help with headaches, tension, and swelling.
For severe cases of ADDE, a doctor may recommend punctum plugs. Punctum plugs are small, biocompatible devices that are inserted into the tear duct that stop your tears from draining too quickly.
Some lifestyle modifications can help make a difference to your condition as well, including getting enough sleep, drinking enough water, choosing cosmetics without harsh ingredients, and getting enough omega-3 fatty acids. Certain nutritional supplements can provide a high daily dose of high-quality omega-3, which helps provide relief and improve DED symptoms.
In Conclusion
If you suspect you might have Dry Eye Disease or experience any discomforting symptoms, it’s always worth paying a visit to your eye care professional. Identifying the type of DED and assessing your symptoms will allow you to find the right management or treatment solutions for your situation.
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[1] Wolffsohn, James S., et al. “TFOS DEWS III Diagnostic Methodology.” American Journal of Ophthalmology, May 2025, https://doi.org/10.1016/j.ajo.2025.05.033.
[2] McMonnies, Charles W. “Aqueous deficiency is a contributor to evaporation-related dry eye disease.” Eye and Vision, vol. 7, no. 1, 1 Feb. 2020, https://doi.org/10.1186/s40662-019-0172-z.
[3] McMonnies, Charles W. “Aqueous deficiency is a contributor to evaporation-related dry eye disease.” Eye and Vision, vol. 7, no. 1, 1 Feb. 2020, https://doi.org/10.1186/s40662-019-0172-z.
[4] Stapleton, Fiona, et al. “TFOS Dews III Digest Report.” American Journal of Ophthalmology, June 2025, https://doi.org/10.1016/j.ajo.2025.05.040.
[5] Fields, Lisa. “Symptoms, Causes, and Treatment for Aqueous Tear-Deficient Dry Eye.” WebMD, www.webmd.com/eye-health/aqueous-tear-deficient-dry-eye. Accessed 25 June 2025.
[6] McMonnies, Charles W. “Aqueous deficiency is a contributor to evaporation-related dry eye disease.” Eye and Vision, vol. 7, no. 1, 1 Feb. 2020, https://doi.org/10.1186/s40662-019-0172-z.
[7] Hodges, Robin R., and Darlene A. Dartt. “Tear Film Mucins: Front Line Defenders of the Ocular Surface; Comparison with Airway and Gastrointestinal Tract Mucins.” Experimental Eye Research, vol. 117, Dec. 2013, pp. 62–78, https://doi.org/10.1016/j.exer.2013.07.027.
[8] Findlay, Quan, and Kate Reid. “Dry eye disease: when to treat and when to refer.” Australian Prescriber, vol. 41, no. 5, 2 Oct. 2018, pp. 160–163, https://doi.org/10.18773/austprescr.2018.048.
[9] Kimball, Samuel H., et al. “Evidence for the Major Contribution of Evaporation to Tear Film Thinning Between Blinks.” Investigative Ophthalmology & Visual Science, vol. 51, no. 12, 1 Dec. 2010, p. 6294, https://doi.org/10.1167/iovs.09-4772.
[10] McMonnies, Charles W. “Aqueous deficiency is a contributor to evaporation-related dry eye disease.” Eye and Vision, vol. 7, no. 1, 1 Feb. 2020, https://doi.org/10.1186/s40662-019-0172-z.
[11] Findlay, Quan, and Kate Reid. “Dry eye disease: when to treat and when to refer.” Australian Prescriber, vol. 41, no. 5, 2 Oct. 2018, pp. 160–163, https://doi.org/10.18773/austprescr.2018.048.
[12] Geerling, Gerd, et al. “Emerging Strategies for the Diagnosis and Treatment of Meibomian Gland Dysfunction: Proceedings of the OCEAN Group Meeting.” The Ocular Surface, vol. 15, no. 2, Apr. 2017, pp. 179–192, https://doi.org/10.1016/j.jtos.2017.01.006.
[13] Kaur, Kirandeep, and Thomas J Stokkermans. “Meibomian Gland Disease.” StatPearls, U.S. National Library of Medicine, 3 Mar. 2024, www.ncbi.nlm.nih.gov/books/NBK580474/.
[14] Findlay, Quan, and Kate Reid. “Dry eye disease: when to treat and when to refer.” Australian Prescriber, vol. 41, no. 5, 2 Oct. 2018, pp. 160–163, https://doi.org/10.18773/austprescr.2018.048.
[15] Zakrzewska, Aleksandra, et al. “The Effect of Oral Isotretinoin Therapy on Meibomian Gland Characteristics in Patients with Acne Vulgaris.” Ophthalmology and Therapy, vol. 12, no. 4, 10 June 2023, pp. 2187–2197, https://doi.org/10.1007/s40123-023-00737-6.
[16] Geerling, Gerd, et al. “Emerging Strategies for the Diagnosis and Treatment of Meibomian Gland Dysfunction: Proceedings of the OCEAN Group Meeting.” The Ocular Surface, vol. 15, no. 2, Apr. 2017, pp. 179–192, https://doi.org/10.1016/j.jtos.2017.01.006.
[17] Qiao, Jing, and Xiaoming Yan. “Emerging treatment options for meibomian gland dysfunction.” Clinical Ophthalmology, Sept. 2013, p. 1797, https://doi.org/10.2147/opth.s33182.
[18] Epitropoulos, Alice, and Arjan Hura. “Exploring the Reversibility of Meibomian Gland Atrophy.” Ophthalmology Times, 15 Nov. 2020, www.ophthalmologytimes.com/view/exploring-reversibility-meibomian-gland-atrophy.