Patient Education
Please feel free to learn about various vision conditions. If you think that you may be affected by a vision problem do not hesitate to contact our office to arrange for an eye care appointment. 978.744.1177
Glaucoma Definition
Glaucoma is a disease of the optic nerve which can over time lead to vision loss and blindness. The optic nerve is a bundle of over 1 million nerve fibers, analogous to a cable that transmits signals from the back of the eye to the brain. Glaucoma is associated with the death of these healthy nerve fibers over time. Initially, this leads to loss of peripheral vision which most often is undetectable to the patient. As the disease progresses it affects the central vision at which point substantial damage to the optic nerve has already been done.
Cause
Many forms of glaucoma exist. These include open-angle glaucoma, angle-closure glaucoma, congenital glaucoma and many secondary forms of glaucoma. In open-angle glaucoma, fluid is produced by the ciliary body, a structure in the back of the eye behind the iris, and flows towards the anterior chamber, the front portion of the eye. When fluid reaches the front part of the eye, it drains through the spongy tissue called the trabecular meshwork. In a sense, the eye can be thought of as having a faucet and a drain that controls the amount of fluid it holds. When too much fluid builds up, it can permanently damage the optic nerve which is a pressure sensitive tissue. Loss of optic nerve tissue leads to loss of vision since the eye does not have a healthy cable to relay these signals to the brain. This type of glaucoma can develop in eyes that have high or even seemingly normal eye pressure. This differs from angle closure glaucoma, where fluid produced by the eye cannot reach its drainage system because it is blocked by iris tissue, the colored part of the eye. In congenital glaucoma, children are born with trabecular meshwork that is defective and does not drain properly. Secondary glaucomas can develop as a result of pre-existing eye conditions such as a cataract, tumor, or inflammation to name a few. Open-angle glaucoma tends to be the most prevalent form of glaucoma. A few risk factors for the development of this type of glaucoma include African American race, increased age, and a family history of the disease.
Symptoms
Glaucoma often goes undiagnosed because in most cases it is not associated with any eye pain. It can also go undetected for a while because it initially causes loss of peripheral vision before affecting the central, most noticeable, part of our vision. Your ophthalmologist can perform a comprehensive eye exam and order specific glaucoma tests designed to diagnose and monitor your condition.
Treatment
There is no cure for glaucoma. All treatment is geared towards slowing down the disease process. There are three main treatment options. The first is medications in the form of eye drops or pills. The medications act to either decrease the rate of fluid production or increase the rate of drainage. Laser surgery can also be used to help stimulate the outflow of fluid. This is a procedure that can be performed at your doctor’s office and may require repeated attempts in order to be effective. The last option is conventional surgery. This is performed in a hospital setting. The purpose is to physically create another drainage site for the eye allowing for the pressure to be more effectively managed.
Definition
Uveitis is inflammation of the uvea. The uvea is the vascular layer of the eye in between the retina and the white part of the eye known as the sclera. The uvea extends toward the front of the eye and consists of the iris, choroid layer, and ciliary body. The most common type of uveitis is an inflammation of the iris called iritis. This eye condition can be very serious resulting in permanent vision loss.
Cause
Uveitis is caused by an immune reaction mounted by the body. Often times this immune reaction can be triggered by infections such as herpes, syphilis or toxoplasmosis among many others. It can also be found in association with autoimmune disorders such as lupus and rheumatoid arthritis or systemic diseases such as sarcoidosis.
Symptoms
The patient often presents with a painful, red eye accompanied by light sensitivity and tearing. Vision tends to be blurred and occasionally the patient may notice some floaters.
Treatment
The goals of treatment are to reduce pain and inflammation. Patients are placed on steroid drops to bring the inflammation under control. If the inflammation cannot be controlled with steroid drops, steroid injections or oral steroids can also be used. If steroids do not help, your ophthalmologist may recommend that you be treated with other systemic immunosuppressive medications. Sometimes the patient is also placed on a dilating drop to help reduce the pain associated with inflammation. If the uveitis recurs, your ophthalmologist may want to investigate for an underlying cause such as an infection or autoimmune disease.
Definition
Blepharitis is an inflammation of the eyelid margin, which often occurs together with meibomitis, a blockage of the oil glands of the eyelids, which are located at the lid margin. Interference of the normal function of these oil glands can reduce the quality and smoothness of the tear film.
Cause
Blepharitis and meibomitis may be caused by chronic infection, most often from Staphylococcus or Demodex. Blepharitis may also occur as a form of eczema, or as a manifestation of rosacea.
Symptoms
Patients with blepharitis may experience itchy, gritty or burning eyes. The eyes may appear red, and the irritation is often worse in the morning than it is late in the day. The eyelid margin may appear slightly thickened or red, and flakes or crusting along the eyelashes may occur.
Treatment
Warm compresses are applied to the eyelids to soften the blockage of the oil glands. Lid scrubs are used to clear bacteria and crust buildup from the eyelids. Artificial tears are used to supplement the tear film. In some cases, an antibiotic drop or ointment is indicated. In chronic blepharitis associated with ocular rosacea, an oral medication may be prescribed.
Definition
Keratoconus is a progressive thinning of the cornea, the clear”window” at the front of the eye. This thinning of the cornea makes it more susceptible to the normal pressure inside the eye, causing the cornea to bulge outward, in a cone-like shape. Irregular astigmatism is caused by the bulging cornea, resulting in blurry or distorted vision.
Cause
The underlying cause of keratoconus is not fully understood. Studies have suggested a genetic link, however, most patients with keratoconus do not have another family member with the condition. Genetic studies suggest a deficiency in the collagen structure of the cornea in patients with keratoconus, resulting in weaker support of the shape of the cornea. There is a higher incidence of keratoconus in patients with atopic disease, such as eczema, asthma or a chronic allergy. Because the cornea of patients with keratoconus is thinner and structurally weaker than a normal cornea, it is more susceptible to minor trauma. Patients with keratoconus should never rub their eyes, as there is a link between frequent eye rubbing and progression of the disorder.
Symptoms
Patients with keratoconus may experience blurry or distorted vision that is not improved with spectacles. An untrained observer will not usually notice anything abnormal about the appearance of an eye with keratoconus, however, your eye doctor can detect changes in the shape of the eye with a keratometer or corneal topographer, and can often observe changes in the appearance of the cornea with a slit lamp microscope.
Treatment
Patients with mild cases of keratoconus may be able to achieve the adequate vision through spectacles or specialty soft contact lenses. Many patients with keratoconus are fit with rigid gas permeable contact lenses. The rigidity of the lens allows the tears to pool under the contact lens, creating a more optically smooth surface by masking irregular astigmatism. Some patients will need to wear glasses over the contact lenses in order to achieve optimal vision correction. In advanced cases of keratoconus, patients may be unable to be successfully fit with rigid contact lenses. These patients may be fitted with a scleral lens, a large diameter specialty lens, or a corneal transplant may be indicated. Currently, procedures designed to slow the progression of the disorder through collagen crosslinking are being evaluated in clinical trials.
Definition
A pterygium is a triangular shaped fibrous growth of tissue that begins on the conjunctiva and overlaps a portion of the cornea. A pterygium most often begins as a pinguecula, an elevated, yellowish-white deposit of collagen tissue underlying the surface of the conjunctiva. Fine blood vessels are visible within the pterygium, resulting in a pink appearance to the growth.
Cause
The most common cause of pterygium is chronic sun and wind exposure and is most prevalent in those who have lived close to the equator or who work outdoors.
Symptoms
While often asymptomatic, some patients with pterygium may notice redness of the eyes, or be concerned by the physical appearance of the pterygium. Patients with an elevated pterygium may notice a gritty sensation if the surface does not remain coated by the tear film. In severe cases, the pterygium may grow into the center of the cornea and interfere with vision. A pterygium may inhibit contact lens wear.
Treatment
In most cases, the only treatment necessary is lubrication with artificial tears to prevent drying out of the elevated surface of the pterygium. Occasionally, the pterygium may become inflamed, and a topical vasoconstrictor or steroid may be indicated. In severe cases, where vision is affected, the pterygium may be surgically removed; however recurrence of pterygium may occur.
When someone has a corneal dystrophy one or multiple parts of the cornea will lose regular clearness or clarity due to a build-up of cloud-like materials. Corneal dystrophies are numerous and may affect all aspects of the cornea. Some of the symptoms include:
- Both eyes are affected
- Can occur in healthy people
- In most cases, they are inherited
- They are not typically caused by outside or environmental factors
Corneal dystrophies can cause widespread visual impairment. If you are concerned about this eye problem or would like to seek a second opinion our eye doctors are here to help.
Definition
A corneal ulcer represents a breakdown in the surface cells of the cornea accompanied by an infiltrate. An infiltrate appears to be a whitish opacity in the eye, but in reality, it represents a collection of white blood cells. Ulcers can be infectious or sterile (non-infectious) in nature. Your ophthalmologist can distinguish between the two forms and treat you accordingly.
Cause
Most infectious ulcers are caused by bacterial organisms and therefore most ulcers are treated as such until proven otherwise. If an ulcer is small, it is typically treated without obtaining any cultures. If an ulcer is large, your ophthalmologist may choose to obtain cultures for further evaluation. Culturing the cornea is a way of identifying which organisms are responsible for the infection. While bacteria are the most common culprits, an infection can be caused by a virus such as herpes or a fungus or even a protozoan. As a rule of thumb, infectious ulcers tend to be extremely painful and rapidly progressive. Risk factors for infectious ulcers include sleeping in or wearing contact lenses for extended periods of time, improper cleaning or handling of contact lenses, having a history of dry eyes, or incurring any trauma to the cornea among many others.
Noninfectious ulcers tend to have a milder presentation. In many cases, they represent a vigorous immune reaction to an inciting factor. In many patients, the coexistence of lid margin disease, also known as blepharitis, is the inciting factor. Contact lens wearers can also develop a noninfectious ulcer, but this tends to be a diagnosis of exclusion.
Symptoms
Patients tend to complain of the following symptoms:
- pain
- redness
- blurry vision
- light sensitivity
- discharge
- contact lens intolerance
They may also notice a white opacity on their cornea.
Treatment
The treatment of corneal ulcers is tailored to the cause. For infectious ulcers, patients are started on medicated eye drops aimed at targeting the specific organism. If the patient wears contact lenses, they are asked to dispose of the current contacts and refrain from further use until the treatment course is completed. If the infection is extensive, the patient may need to be hospitalized for aggressive treatment which can involve taking eye drops every 30 minutes. For sterile or noninfectious ulcers, patients may be placed on a steroid drop along with an antibiotic drop.
