Dry Eye
What is dry eye?
Normally, the eye constantly bathes itself in tears. When tears are produced at a slow and steady rate, the eye stays moist and comfortable. In some cases, people do not produce enough tears or the appropriate amount required to keep eyes healthy and comfortable. This is known as dry eye.
What are the symptoms of dry eye?
Symptoms usually include:
- stinging or burning eyes;
- scratchiness;
- excessive eye irritation from smoke or wind;
- excess tearing;
- discomfort when wearing contact lenses
What is the tear film?
When you blink, tear film spreads over the eye making the surface smooth and clear. This film of tears is essential for maintaining good vision.
The tear film consists of three layers:
- an oily layer
- a watery layer
- a layer of mucus
Each layer of the tear film has its own purpose. The oily layer, produced by the meibomian gland, forms the outermost surface of the tear film. This layer is responsible for smoothing the tear surface and reducing the evaporation of tears. The middle watery layer makes up most of what we ordinarily think of as tears. This layer, which is produced by the lacrimal gland, cleanses the eye and washes away foreign particles. The inner layer consists of mucus and is produced by the conjuctiva. Mucus allows the watery layer to spread evenly over the eye surface and helps retain moisture. Without mucus, tears would not stick to the eye.
What causes dry eye?
Tear production normally decreases as we age. Although dry eye can occur in both men and women at any age, women are most often affected.
Dry eye can also be associated with other problems. A wide variety of medications-both prescription and over-the-counter-can cause dry eye. Be sure to tell your ophthalmologist the names of all the medications you are taking.
How is dry eye treated?
Adding tears
Eyedrops containing artificial tears are similar to your own natural tears. They help to lubricate the eyes and maintain moisture. They may be used once or twice a day or as often as necessary.
Conserving your tears
Tears drain out of the eye through a small channel into the nose (which is why your nose runs when you cry). Your ophthalmologist may close these channels either temporarily or permanently. This conserves your own tears and makes artificial tears last longer.
Other Methods
Tears evaporate like any other liquid. You can take steps to prevent this. In winter, a humidifier adds moisture to dry air. Wrap-around glasses help reduce the drying effects of the wind.
More information is located at The American Academy of Ophthalmology. www.aao.org
We recommend RESTASIS™
RESTASIS™ Ophthalmic Emulsion is both an artificial tear to treat your symptoms in the short term combined with medicine to treat your dry eye disease in the long term. RESTASIS™ Ophthalmic Emulsion actually helps you restore your own natural tears- something that an artificial tear cannot do by itself!
RESTASIS™ Ophthalmic Emulsion costs more than artificial tears because of its unique formulation. If you have a prescription drug card, RESTASIS™ may be covered by your insurance plan for a modest co-pay.
Many patients experience relief from their symptoms of itching, grittiness, blurred vision, and light sensitivity within their first month of therapy. For patients who have struggled with dry eye disease for many years, RESTASIS™ may take two to three months- with a maximum of six months- to achieve full relief.
Remember, dry eye is a chronic disease that requires your long-term commitment- and that means taking your RESTASIS™ everyday.
For more information, please visit www.restasis.com.
Dry eye testing
Testing for dry eye syndrome includes evaluation of the tear film layer and "tear lake" (an accumulation of tears along the lower eyelid margin), Schirmer testing, evaluation of the tear break-up time, and rose bengal staining.
Schirmer Testing involves placing a thin tear strip (paper) inside the lower eyelid for a given interval of time (usually 5 mnutes), with or without topical anesthesia. The tear strip is then removed and the length of the strip that is wet from tears is measured and compared to a standard. Individuals with dry eye syndrome will have less wetting of the tear strip than normal controls.
Tear Break-Up Time (TBUT) is another method of evaluation for dry eye syndrome. The ophthalmologist applies fluorescein dye to the tear film, asks the patient not to blink momentarily, and then times the interval until dry spots begin to occur on the corneal surface. This interval of time is known as the TBUT, and the interval is decreased in patients with dry eye syndrome.
Rose Bengal Staining is yet another method of evaluating patients for dry eye syndrome. Rose bengal is a dye that, when applied to the ocular surface, is taken up by devitalized (sick) epithelial cells. Positive staining of the conjunctiva with rose bengal is consistent with a diagnosis of dry eye syndrome.
Ptosis (eyelid) In ophthalmology, ptosis is an abnormally low position (drooping) of the upper eyelid which may grow more or less severe during the day.
Causes
Ptosis occurs when the muscle that usually raises the eyelid (levator palpebrae superioris) is not strong enough to do so. It can affect one eye or both eyes and is more common in the elderly, as muscles in the eyelids may begin to deteriorate. One can, however, be born with ptosis, as it is hereditary. Ptosis may be caused by damage/trauma to the muscle which raises the eyelid, or damage to the nerve which controls this muscle. Such damage could be a sign or symptom of an underlying disease such as diabetes mellitus, a brain tumor, and diseases which may cause weakness in muscles or nerve damage, such as myasthenia gravis.
Classification
Depending upon the cause it can be classified into:
- Neurogenic ptosis which includes IIIrd cranial nerve palsy, Horner's Syndrome, Marcus Gunn jaw winking syndrome, IIIrd cranial nerve misdirection.
- Myogenic ptosis which includes myasthenia gravis, myotonic dystrophy, ocular myopathy, simple congenital ptosis, blepharophimosis syndrome
- Aponeurotic ptosis which may be involutional or post-operative.
- Mechanical ptosis which occurs due to edema or tumors of the upper lid
- Neurotoxic ptosis which is a classic symptom of envenomation by elapids such as cobras or kraits etc. Neurotoxic ptosis is a precursor to respiratory failure and eventual suffocation caused by complete paralysis of the thoracic diaphragm. Urgent medical intervention is therefore required.
Treatment
Treatment depends on the type of ptosis.
Aponeurotic and congenital ptosis may require surgical correction if severe or if cosmesis is a concern. Surgical procedures include:
- Levator resection
- Frontalis sling operation
Non-surgical modalities like the use of "crutch" glasses to support the eyelid may also be used.
Ptosis that is caused by a disease will improve if the disease is treated successfully.
References
Entropion Repair
An entropion is an inwardly turned (inverted) eyelid. The condition occurs primarily as a result of advancing age with consequent weakening of certain eyelid muscles. The imbalance between eyelid muscle groups results in the inward turning of the eyelid. This condition most often affects the lower eyelids, but may also affect the upper eyelids. Entropion repair may be completed with a variety of procedures. Most cases are completed with an incision in the outer corner of the eye to tighten the lower eyelid.
Most patients experience immediate resolution of the problem once surgery is completed with little if any post-operative discomfort. Most cases will require removal of sutures located along the lower eyelashes or the outer corner of the eyelid. Minor bruising or swelling may be expected and will likely resolve in seven to ten days following surgery.
A non-incisional entropion repair, known as a Quickert procedure, may be completed as an in-office procedure. This form of entropion repair requires two or three strategically placed sutures which will evert the eyelid. The procedure can be completed under local anesthesia with little if any discomfort.
The most important drawback of the Quickert procedure is that there is a significantly higher chance of recurrence of the entropion. However, it is an excellent procedure for patients who are not good candidates for procedures under anesthesia.
Ectropion Repair
An ectropion is an outwardly turned (everted) eyelid. The condition most often is associated with aging, though it may also occur congenitally, as a result of scarring or other surgeries, or secondary to facial nerve paralysis (Bell's palsy). If not repaired, the condition may lead to thickening of the surface on the inside of the eyelid, inflammation, and cause danger to the health of the eye itself.
The best method of repair for an ectropion often depends on the underlying cause. Involutional ectropion is associated with aging. To repair this most surgeons elect to shorten and tighten the lower lid, thereby resolving the outwardly turned lid. This typically is completed with an incision of the skin at the outer corner of the eyelid. The surgeon then excises a small segment of the lower eyelid, and subsequently reconnects the eyelid to underlying tissues and the upper eyelid.
Usually only a few stitches are placed in the skin at the outer corner of the eyelid, and these are often removed 7 to 14 days later. There is typically almost immediate resolution of the condition. Most patients have little if any discomfort with the procedure. There may be mild bruising and swelling following the procedure. This should resolve within about 7 to 14 days.
Cicatricial ectropion occurs as a result of scarring and is most likely to follow another surgical procedure of the face or eyelids, especially excision of skin lesions such as skin cancers. This type of ectropion repair often requires skin grafting. The donor site for the skin graft is most often taken from the patient's upper eyelid or from behind the ear. The skin from these sites will most closely match that of the patient's lower eyelid skin. Both the donor site for the graft and the surgical site will usually heal nicely within two weeks following the surgery.
References: eyemdlink.com
Lacrimal Duct Obstruction
Congenital Nasolacrimal Duct Obstruction
Congenital nasolacrimal duct obstruction (CLDO) is literally a tear duct that has failed to open at the time of birth. Around 6% of infants have CLDO, usually experiencing a persistent watery eye even when not crying. If a secondary infection occurs, purulent (yellow / green) discharge may be present.
Most cases resolve spontaneously, with antibiotics reserved only if conjunctivitis occurs. Lacrimal sac massage has been proposed as helping to open the duct, though this is not always successful. The aim of massage is to generate enough hydrostatic pressure (downward, toward the nose) to "pop" open any obstruction. Additional massage may then be performed up toward the lacrimal punctum, in order to express any infectious material out of the nasolacrimal sac. When discharge or crusting is present, the lids should be gently cleaned using cooled pre-boiled water or saline.
Referral to Dr. Vick is indicated if symptoms are still present at 12 months, or sooner if significant symptoms or recurrent infections occur. Nasolacrimal duct probing may be performed in the office setting (usually from 4 to 8 months of age) or under general anesthesia in an operating room for older patients. The success rate of probing is higher for younger children. A silastic tube or stent may be employed along with probing to maintain tear duct patency.
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