If your eyes burn, sting, feel gritty, or blur until you blink, you have probably already tried a bottle or two of artificial tears. For some people that is enough. For many it is not, and the reason is simple: "dry eye" is not one problem. It is the end result of at least three different problems, and each one needs a different treatment.
At the Dry Eye Center at Eye MDs of Inland, we do not start with a product. We start by asking which of the three causes is at work in your eyes. Often it is more than one.
Your tear film has a job to do
Every blink spreads a thin film of tears across the front of the eye. That film has a watery layer made by the lacrimal gland, and a thin layer of oil on top made by the meibomian glands, the small oil glands that line the edges of your eyelids. The oil keeps the watery layer from evaporating. The eyelids spread the film and hold it against the eye.
When any one of those three parts fails (the water, the oil, or the lids), the surface of the eye dries out. That gives us the three causes an eye doctor looks for.
Cause 1: Your eyes do not make enough tears
Doctors call this aqueous deficient dry eye. The lacrimal gland simply produces too little of the watery part of the tear film. Common reasons include:
- Age and menopause. Tear production tends to fall as we get older, and hormonal changes at menopause play a role.
- Sjogren's syndrome and other autoimmune diseases. Sjogren's syndrome typically causes dry eye together with dry mouth and is seen mostly in women over 40.
- Medications. Antihistamines, antidepressants, diuretics, and isotretinoin can all reduce tear production.
- A history of LASIK.
If we suspect Sjogren's syndrome, we arrange blood work (SS-A/Ro, SS-B/La, ANA, and RF) and work together with a rheumatologist. You can read more on our Sjogren's syndrome and dry eye page.
Cause 2: Your tears evaporate too quickly
This is the most common cause by far. In one clinic-based study, about 86 percent of patients with dry eye had an evaporative component (Lemp et al., Cornea, 2012).1 The usual reason is meibomian gland dysfunction (MGD): the oil glands in the eyelids become blocked, the oil thickens, and the watery layer of the tear film evaporates between blinks.
MGD is closely linked to blepharitis (inflammation of the eyelid margins), to rosacea, and to Demodex, a microscopic mite that lives in the lash follicles. Demodex accounts for about 45 percent of blepharitis, and its telltale sign is collarettes, small waxy cuffs at the base of the lashes. Recurring styes and chalazia are another clue that the oil glands are struggling.
One fact makes this cause urgent: when a meibomian gland is lost, a change doctors call gland dropout, it does not come back. Treating MGD early protects the glands you still have. Learn more about meibomian gland dysfunction and LipiFlow and about blepharitis and Demodex.
Cause 3: Your eyelids are not protecting the eye
The third cause is anatomic, and it is the one most often missed. If the eyelids do not sit against the eye or do not close fully, even healthy tears cannot stay where they belong. Examples include:
- Ectropion, an eyelid that turns outward.
- Entropion, an eyelid that turns inward.
- Lagophthalmos, eyelids that do not close completely.
- Floppy eyelid, ptosis (a drooping upper lid), and scarring.
No drop can correct an eyelid that is out of position. This cause needs a surgical repair, which is why our Dry Eye Center includes eyelid surgery for dry eye alongside medical treatment.
Why the cause matters more than the drop
Artificial tears add moisture for a short time. They do not unblock an oil gland, calm an autoimmune condition, or reposition an eyelid. If the oil layer is the problem, added water evaporates just as fast as your own tears did. If the lid is the problem, drops run off. This is why so many people feel stuck after months of trying different bottles.
Many patients have more than one cause at once. A woman in her sixties may make fewer tears, have blocked meibomian glands, and take an antihistamine every night. Each piece needs its own answer.
How we find your cause
A comprehensive dry eye evaluation is built to sort out the three causes. It includes:
- A symptom questionnaire (SPEED or OSDI) to measure how much dry eye affects your day.
- A slit-lamp exam of the eye surface, lids, and lashes, including a check for Demodex collarettes.
- Tear break-up time (TBUT), which shows how quickly your tear film evaporates.
- Fluorescein and lissamine green staining, which highlight dry or damaged areas on the eye surface.
- A Schirmer test, which measures how many tears you make.
- Meibomian gland expression and meibography, which show how well the oil glands work and whether any have been lost.
- An assessment of eyelid position and blinking.
- A review of every medication you take.
- Tear osmolarity and MMP-9 testing when indicated.
Treatment matched to the cause
Once we know the cause, treatment becomes far more direct:
- Not enough tears: prescription anti-inflammatory drops (the cyclosporine or lifitegrast class), punctal plugs made of silicone or dissolvable collagen that are placed in minutes in the office, Lacrifill canalicular gel, or autologous serum tears.
- Tears that evaporate: lid hygiene with warm compresses and hypochlorous acid or tea tree lid scrubs, omega-3, LipiFlow thermal pulsation for blocked meibomian glands, and Xdemvy (lotilaner 0.25 percent), the first FDA-approved treatment for Demodex blepharitis.
- Eyelid position: ectropion or entropion repair, ptosis repair, or lid tightening.
- Flares: Eysuvis (loteprednol etabonate 0.25 percent), which is FDA-approved for short-term treatment, up to two weeks, of the signs and symptoms of dry eye disease.
Our dry eye treatments page describes each option in detail. Do not stop a prescribed medication on your own because you think it may be drying your eyes. Talk with the doctor who prescribed it first.
The bottom line
If your eyes are still dry after you have tried artificial tears, it does not mean nothing will help. It usually means the cause has not been identified yet. The Dry Eye Center at our Upland office looks for all three causes at one visit, so treatment can be aimed at the real problem.
Works Cited
1. Lemp MA, Crews LA, Bron AJ, Foulks GN, Sullivan BD. Distribution of aqueous-deficient and evaporative dry eye in a clinic-based patient cohort: a retrospective study. Cornea. 2012;31(5):472-478.
