Dry Eyes

The normal cornea is very sensitive to touch, foreign body sensation, and mild superficial injury. Anyone who has ever had an eye infection, contact lens-related irritation or corneal scratch knows this to be true. A network of sensory nerves provides this exquisite sensitivity. In LASIK, creation of the flap causes some of these nerves to be cut, which actually diminishes sensitivity. I tell patients that it is as if “the phone lines are down;” such that the eye surface cannot send requests to the tear gland when additional moisture is needed. Typically, these nerves do grow back, and sensitivity returns to reasonably normal levels within several months of treatment.

Laser Eye Correction Riverside

What is Dry Eye Syndrome?

Dry eye is a condition that occurs when your tears can’t lubricate your eyes. This usually happens because your eyes cannot produce enough tears or the tears produced are low-quality.

Tears are what keep your eyes healthy. They also make sure your vision stays clear. When your eyes don’t produce enough tears, you may feel uncomfortable.

If you leave dry eye untreated, it could lead to permanent vision problems that get worse over time.

What is Dry Eye Syndrome?

You might have dry eye if:


  • Your eyes sting, burn, or feel scratchy
  • You become more sensitive to light
  • Your eyes are watery or tear up easily
  • Your eyes are red
  • You feel like there’s something in your eye
  • You have trouble wearing contact lenses
  • You find it difficult to drive at night
  • Your eyes get tired or feel fatigued
  • Your eyes produce a stringy mucus
  • Your vision becomes blurrier and things become harder to see clearly

If you have any of these symptoms and they do not get any better, see Dr. Cheng for treatment. It’s important to seek treatment sooner than later to avoid any permanent damage to your vision.

How is Dry Eye Diagnosed?

If you suspect you have dry eye, make an appointment with your eye doctor. They will ask about your symptoms and lifestyle. They’ll also examine your eye and perform tests that measure your tears.

This includes measuring both the quantity and the quality of the tears you produce. They may also put special dyes in your eyes. These allow them to look at how tears flow from your eyes and if there are any problems with this process.

What Causes Dry Eye?

If you have dry eyes, this can be due to a few different things. Your dry eye might be happening because your eyes can’t produce enough tears. Decreased tear production can be caused by factors such as:

  • Aging
  • Medical conditions including diabetes, rheumatoid arthritis, and thyroid disorders
  • Some medications like antihistamines, antidepressants, and medications for high blood pressure

You can also develop dry eye if your tears evaporate too quickly due to dry air and the environment you live in. You may also have eyelid problems, you don’t blink as much as you should, or you could have an issue with your tear film.

Tears need to cover the full surface of the eye to provide necessary nutrients and keep the eye lubricated. An issue with the tear film could cause the tears to evaporate from the eyes too quickly and not cover the complete surface of the eye.

Some people are more at risk for dry eye.

You’re more likely to have dry eye if you are:

  • Older than 50
  • Female
  • Eating a diet that’s low in vitamin A or omega-3 fatty acids
  • Wearing contact lenses

Does Dry Eye Have Any Complications?

If you have dry eye, you can also develop other complications as well. When your eyes don’t produce enough tears, you become more likely to develop eye infections. Severe dry eyes can cause other vision problems like eye inflammation. This is why it’s so important to seek treatment for your dry eyes as soon as possible!

Early diagnosis leads to earlier treatment, letting your eyes recover.

Can I Treat My Dry Eye On My Own?

The normal human tear film is about 98% water (with dissolved minerals or “salts” including sodium, potassium and calcium), about 1% lipid (an oily film that reduces evaporation, reduces “tear breakup” and helps the lids glide smoothly over the corneal surface), and about 1% mucopolysaccharide (the “mucus” component, long water-soluble molecules that further stabilize the tear film, and promote adherence to the corneal epithelium). The watery portion of human tears are created by a combination of the tear gland and special mucin-secreting cells on the ocular surface.

Maintaining good hydration is essential to keeping the eyes comfortable, and I encourage three things to accomplish this:

    • Drinking adequate water or fluids ;
    • Use of artificial tears at least for the first 8-12 weeks after LASIK; and thereafter as desired to maintain comfort;
    • Use of a small room humidifier when appropriate.

Humidifiers are widely available at pharmacies, linen and bath supply stores, Costco and other retail sources. Many people already own one if they have kids, as they are commonly recommended as adjunct therapy for children with respiratory problems (croup, asthma, bronchitis, bad colds, etc.). They range in cost from about $25 to over $100, but very decent ones are typically around $50 (which is about the same as the cost of three bottles of “vanishing preservative” artificial tears). I advise putting the humidifier in the room where it will do the most good (bedroom, home office, etc.). Then, instead of dry air sucking moisture out of the eyes, moist air can actually keep the eye surface comfortable.

Good lid hygiene is important to maintenance of a good lipid tear layer. This is where all the advice about blepharitis, lid scrubs, hot compresses lid hygiene and lid massage comes in. If the lipid component breaks down, no amount of artificial tears will solve the problem. We treat blepharitis when appropriate, and endorse the use of moisturizing creams and/or lotions for the eyelid skin in those people that desire to use these products.

In some people, beneficial effects are achieved with omega-3 fatty acid dietary supplements.   Several companies offer over-the-counter supplements with such oils and fatty acids including ” Thera-Tears Nutrition ” and others.

A commercially available spray called Soothe contains lubricants and lipids, claiming to “stabilize the lipid layer of the tears” and promote overall tear stability.

Be aware of other factors that can affect the water and lipid layer of tear film. These include:

  • Use of diuretics, as these medications remove water from the system;
  • Use of antihistamines, either topical (eye drop) or systemic can have a drying effect, as they reduce secretions; the tear gland after all is a secretory gland too. 
  • Intake of alcohol.   Even when consumed in modest or small quantities, alcohol gets into the bloodstream and the tears.  It reduces surface tension of the tear film, leading to increased evaporation.
  • Cigarette smoking.  The particulate nature of cigarette smoke can be directly irritating to the eyes, and the chemicals that are inhaled can adversely affect both ocular surface blood flow, tear secretion, and tear quality.
  • Use of sedatives, sleep aids, or muscle relaxants.   These all can decrease muscle tension, and can lead to incomplete closure of the eyes during sleep.  If the eyes open even a little, evaporative tear loss can create significant dry-eye symptoms most notable upon arising in the morning.
  • Use of cologne, perfume, fragrance, or after-shave on or around the face.  Why?  All these substances are bottled in liquid containing — you guessed it — alcohol, so each spray or splash is basically giving the eyes a large, direct dose of the bad stuff we described above.
  • Use of make-up, particularly certain eye-liners which can affect the lipid layer of the tears and decrease tear break-up time. I support use of hypo-allergenic cosmetics, taking all the usual precautions, etc.;
  • Air travel .  On commercial and private aircraft, cabin air is very dry, as the air is both dehumidified and cooled.  If travelling by air within 3 months of LASIK, it is advisable to use artificial tears as often as every half hour while the plane is in flight (unless your eyes are closed as in sleep).
  • Use of any “get the red out” drops containing vasoconstrictors (Visine, Naphcon-A, Opcon-A and others) because, when the drops wear off, there can be a rebound effect leading to more congestion, more perceived need to use more drops, etc.;
  • Use of tears containing polyvinyl alcohol as the vehicle (Visine is one example, for the same reasons as “alcohol” above);
  • Use of certain medications including Acutane.  Acutane adversely affects oil production by the eyelid meibomian glands, and is actually a known contraindication to LASIK per the FDA guidelines.
  • Blink frequency and disruption of normal blinking .  People that become intensely focused on work, particularly using computers, often blink with decreased frequency.  This can lead to drying of the eye surface. The same factors hold true for people with certain hyper-thyroid conditions.
  • Exposure to hot or dry air in occupational contexts;
  • Exposure to turbulent air, particularly hot and dry turbulent air, as encountered when styling and blow-drying hair and other reasonably common situations (even driving with the window open, or the top down, or the A/C blowing), etc.;
  • Exposure to drafts, breezes, or moving air from central heating or A/C systems.   Often simply adjusting the fins on the duct openings to steer the moving air away from one’s face can afford dramatic reduction in discomfort;
  • Exposure to aerosol chemicals or sprays that can be toxic or irritating;

Overnight lubrication with ointment or gel if necessary . For some people, it is very helpful to use lubricant ointment or gel preparations just before retiring for the night. We have used Thera-Tears Liqui-Gel and GenTeal Gel   preparations with moderate success.

Punctal Plugs . Normally, tears from the eye drain through a tiny channel to the nasal passages. The openings from the eyelid edge into the tear duct (there are normally two in each eye, near the nasal corner of each upper and lower lid) are called the puncta. Placing either a temporary (collagen) or permanent (silicone) plug in the punctum can reduce the rate of drainage of tears from the eye surface. At LA Sight we place the temporary (collagen) plugs with some frequency but use the more permanent (silicone) plugs only very rarely, and only in the lower lid puncta.  I have almost never found it necessary to place plugs in both the lower and upper lid puncta.

Prescription medications when necessary . In 2005 the FDA approved Restasis for use in treatment of severe dry eye and ocular surface disease. I have used this on rare occasion with limited success. On extremely rare occasion, other medications may be appropriate including estrogen or androgen cream (these would need to be made up by a compounding pharmacy), Salagen drops (used typically in the context of patients with Sjogren’s syndrome), or Diquafosol (not yet FDA-approved).  Dr. Cheng also is aware of research studies involving other drugs and treatment regimens; and may if other methods fail advise participation in one of these investigational studies.

Preparation of special Autologous serum-containing tears .  Some experts feel that the addition of serum proteins to preservative-free tears affords a natural and supportive environment to the tear film, which can restore comfort. Serum is a component of human blood (the fluid remaining after clotting factors and blood cells are removed) so requires blood drawing and preparation by a medical professional.  We have found this to be of value after PRK surgery in rare cases but have not employed this to treat dry eye save for very exceptional cases.

How Can I Treat Dry Eye If Home Remedies Didn’t Help?

When at home remedies and treatments aren’t enough to treat dry eye symptoms, Dr. Cheng offers several procedures as part of our dry eye treatments. They include the following:

Meibomian Gland Expression

Your eye doctor can drain the meibomian glands in your eye to help your eye produce tears more easily. Meibomian glands are oil glands along your eyelid.

They produce oil that is part of your eyes’ tears. Meibomian gland expression is not painful and uses a special instrument to unblock the glands.

This expresses any stagnant secretions from the glands that blocked the gland opening, which often leads to irritation, dry eyes, and tears evaporating from the eye too quickly. Draining the glands with manual expression helps unblock them and increases the chance that new secretions are produced.

Oasis Temporary and Permanent Plugs

his procedure blocks the tear ducts to help your eyes produce more tears. Depending on the severity of your dry eye symptoms, the Oasis punctal plugs come in both temporary and permanent forms.

Oasis punctal plugs begin hydrating the eyes over a period of ten minutes. They are biocompatible, meaning patients don’t run the risk of experiencing a foreign body sensation.

They are also sterile and comfortable for patients. Both forms are easily reversed if needed through irrigation of the tear duct.

Astigmatism Hemet


Over 50% of patients with dry eye syndrome also suffer from blepharitis symptoms. Blepharitis is an inflammation of the eyelids.

The eyelids may become itchy, red, or irritated with scales forming on the eyelashes. This is most often caused by bacteria or a skin condition like rosacea or scalp dandruff.

Dr. Cheng is happy to offer BlephEx, an in-office procedure that removes excess bacteria, biofilm and toxins. These are some of the main causes of dry eye syndrome and blepharitis.

When patients have regular BlephEx treatments, they can finally find relief from the irritating symptoms of dry eye and blepharitis. Most patients tolerate BlephEx quite well, with few side effects and even save hundreds of dollars every year on prescription drops and other medications.

Astigmatism Loma Linda


MiBoFlo dry eye treatment Dr. Cheng offers is a new therapeutic device for treating dry eye. MiBoFlo uses a proprietary thermoelectric heat pump.

This turns dried-up tears into liquid, improving how meibomian glands function. MiBoFlo also helps improve the rate that tears evaporate from the eyes at.

This is a problem for people with dry eyes. The MiBoFlo treatment is short and painless to undergo.


LipiFlow devices remove blockages from your tear glands so the glands can function. This treatment can help your tear glands work correctly.

The LipiFlow Activator treats the meibomian glands. This uses Vectored Thermal Pulse Technology. Feedback loops send pulsed sequences. This removes blockages in the glands.


LipiScan technology uses Dynamic Meibomian Imaging. This takes an image of your meibomian glands, allowing your eye doctor to see how healthy the glands are.