Entries categorized as ‘FAQ’
We are frequently asked to explain how glaucoma causes blindness. Glaucomatous damage to the eye is caused when the pressure within the eye is greater than the optic nerve can tolerate. How does the pressure cause blindess? The simple answer is we don’t know exactly, however there are two main theories as to why the damage occurs. Neither theory fully explains how the optic nerve damage occurs in the different types of glaucoma.
The Vascular Theory of Glaucoma
The premise of the vascular theory is that high pressure inside the eye restricts blood flow to the optic nerve causing the optic nerve to slowly die from lack of oxygen and nutrients.
The Mechanical Theory of Glaucoma
Physical damage is the underlying hypothesis of the mechanical theory of glaucoma. It is thought that the high pressure damages the optic nerve fibers.
So Which One Is It?
That’s a good question the leading researchers can make a convincing case for both theories and neither theory, by itself can completely explain how glaucoma damages the eye. In reality both probably play a role in how an eye is damaged by glaucoma.
Categories: FAQ · Glaucoma · Optic Nerve
Tagged: blindness, blood pressure, Glaucoma, hypertension, Optic Nerve
Are you sensitive to light? Do your eyes often feel gritty? Does your vision fluctuate? Does blinking improve your vision? Do you use artificial tear more than 3 times a day? Find your contact lenses uncomfortable?
These are just a few of the most common symptoms we hear when patients tell us their eyes feel dry and irritated. Dry eye syndrome is very common, especially in women. Treatment of dry eye syndrome is very beneficial with very little risk of complications. Punctal occlusion with silicone plugs is one of the most common modes of treatment.
We often use punctal plugs to increase the amount of tears present in a patient’s eyes. A recent study compared the two most common types of punctal plugs, silicone punctal plugs and the SmartPLUG®. Essentially the study found that they both were relatively equally effective in reducing a patient’s symptoms (over 55% of the patients reduced the use of artificial tears). The study evaluated only 36 eyes for less than 12 weeks which really was not enough patients over too little time. However, one would likely expect that as long as the punctal plugs remained in the eyes the patients would continue to do well. The study does show that treatment of dry eye syndrome with punctal plugs is an effective solution.
Interestingly, 33% of the eyes treated had a plug fall out during the 12 weeks, which is very high. In our practice we see approximately 5% of our patients per year lose a plug, a rate much more in line with other ophthalmic practices. A 33% loss makes me want to look for a problem with punctal plug sizes.
We use both types of punctal plugs used in the study, silicone plugs (made out of a rigid type of silicone) and the SmartPLUG® (made out of a thermodynamic gel). We find both to be very effective and helpful in different situations. I like the silicone plugs for most patients, it is easy to insert and verify that it is still in place doing its job. The SmartPLUG® is helpful in patients that find the silicone plugs irritating.
If you think you are experiencing the symptoms of dry eyes see your eye doctor and get some help. There are numerous treatments available, which we will cover in another article. At a minimum, patients typically note a significant decrease in symptoms with treatment.
If you would like to read a summary of the article it’s available here “SmartPlug versus silicone punctal plug therapy for dry eye: a prospective randomized trial”.
UPDATE: Check out this video on treating Dry Eye Syndrome with punctal plugs at Total Eye Care.
Categories: Cornea · FAQ · dry eye syndrome
Tagged: Contact lens irritation, dry eye syndrome, punctal occlusion, punctal plugs, sjogren syndrome
On Friday, the Food and Drug Administration heard testimony from LASIK patients dissatisfied with the outcome of their surgeries. The ophthalmic devices panel heard testimony that approximately 1/4 of all patients that wished to have LASIK were poor candidates and 95% of LASIK patients were satisfied with the outcome of their surgery. Expert testimony before the panel concluded that the FDA should provide clearer warnings about the risks and possible complications of LASIK. Next year the FDA and the National Eye Institute will begin a landmark study to better identify which patients are more likely to encounter post surgical LASIK complications and how those complications affect quality of life. We compared the incidence of complications for patients having LASIK vs contact lens related complications in a prior blog entry.
I find that the FDA is not the only one that could improve their modus operandi here but that some of the marketing/advertising for refractive surgery is irresponsible. This over promise of results does not apply to just refractive surgery but also the bifocal lens implants promising to give your back your ability to see near and far without bifocals.
At Total Eye Care our role as optometrists is to provide the patient with an objective assessment, finding the best method of vision correction available for each patients situation. Today there are many refractive options available such as contact lenses, glasses, orthokeratology, PRK, LASIK and refractive lensectomies just to name a few. If a refractive option is selected it is our job to work with the patient to find the best surgeon and procedure for each patient to get the best, safest result. The Associated Press had good coverage regarding the ophthalmic devices hearing, if you would like to read it it’s available here.
Categories: Cornea · FAQ · LASIK · Refractive issues
Tagged: FDA, LASIK, LASIK Complications
A: This is a great question that gets asked a lot. The pressure inside your eye is completely unrelated to your blood pressure. The intra-ocular pressure system and the blood pressure are completely separate systems and fluid is not exchanged between them. Therefore, if you have high blood pressure you won’t necessarily have glaucoma.
Categories: FAQ · Glaucoma
Tagged: blindness, blood pressure, Glaucoma, hypertension, Optic Nerve
It’s all over the radio these days a LASIK surgeon touts “some experts believe LASIK is safer than contact lenses”. In reality this is a difficult statement to backup properly, given that we are really comparing apples to oranges. Why is this comparison difficult? Comparing LASIK to another refractive surgery procedure, such as PRK, is rather straight forward because the complications are similar for both procedures and the opportunity for complications is essentially nil after the patient is stable, typically 6 months to a year after surgery. A contact lens wearer, on the other hand, has a lower complication rate. When compared to LASIK or PRK contact lens complications are less severe and less frequent, however, a contact lens wearer’s potential for complications will last as long as the patient is wearing their lenses, often for decades.
Both LASIK and contact lenses are safe and in our office we utilize both techniques, choosing which is best for the patient. It is our practice to discuss all of the refractive options with our patients. We weigh the risks and benefits of each option before proceeding.
As a practical matter the incidence of vision threatening problems in compliant contact lens wearers is very small. When a patient does have a problem, it typically manifests itself as a red eye usually resulting from poor care or not replacing their contacts as often as recommended. It is exceedingly rare for a contact lens related red eye to cause a patient to require surgery to resolve the problem.
This prompts me to ask “what does the research say”. In my mind that’s what matters. Let the studies show us which is safer. The most important contact lens and LASIK complications are those that have resulted in a loss of vision and therefore that is the best criteria to compare LASIK versus extended wear contact lenses. A 2005 study including almost 5,000 patients followed over a 1 year period showed that 30 day Ciba Night & Day contact lens wearers, experienced an overall rate of presumed infiltrative keratitis (a type of corneal ulcer) of 0.18%. Of those experiencing keratitis 0.036% resulted in a loss of vision and 0.144% experienced keratitis without vision loss.
Numerous studies published in 2005 and 2006 indicated a complication rate for LASIK, resulting in a loss of best corrected vision, ranging from 0.6% to 7.0%.
Given the facts outlined above, I feel it is doing patients a disservice to state or imply that refractive surgery is as safe or safer than silicone hydrogel contact lenses. Both LASIK/PRK and silicone hydrogel contact lenses have come a long way in reducing both the rate and severity of complications and in looking at the numbers both are safe.
I still believe LASIK and PRK are good options for patients. I, in fact, have had LASIK and at our office it is still one of the refractive options we present to our patients. However, the research does not support the statement that refractive surgery is as safe as contact lens wear nor should it be promoted as such.
Technorati Tags: Extended Wear, Laser Vision Correction, LASIK, Refractive Surgery, Contact Lenses, Safety
Categories: Cornea · Eye Care · FAQ · LASIK · Refractive issues · Vision · contact lens · examinations · eye
Tagged: comparison, contact lenses, extended wear contact, Laser Vision Correction, LASIK, PRK, refractive surgery, safety
Your baby should have her eyes examined at any age if a
problem is suspected. Until recently eye exams were recommended for all children before they entered kindergarten. However, numerous national organizations such as the American Optometric Association, American Academy of Ophthalmology and Prevent Blindness America have begun to recommend that your child receive their first eye exam at 6 months of age and then again at 3 years of age. Many forms of blindness or amblyopia (a decrease in vision) that occur in children can be prevented if caught early. Before you take your child to your eye doctor ask them if they are set up to evaluate children that are your child’s age. Not all eye doctors see young children.
Categories: FAQ · Vision · children · examinations · eyecare · optometrist
Tagged: child, children, eye exam, eyecare, Vision
A: Generally, seeing spots or “floaters” in you vision is a harmless, but annoying condition caused by particles of natural materials floating in the jelly-like fluid in the back chamber of your eye. These spots are more common with age and treatment is rarely necessary. These spots, however, can also be a symptom of retinal problems such as retinal holes or detachments or as a result of diabetic complications or hypertension. Floaters may be more dangerous if accompanied by flashes of light. These flashes may appear as lightening bolts or merely sparkles that you see to the side of your vision. Evaluation of flashes or floaters requires urgent attention. I always recommend that we see patients with flashes and floaters to differentiate the cause of these symptoms.
Technorati Tags: floater, eye, vitreous, spots, flashes
Categories: FAQ · Retina · emergency
A: Accurate results can be obtained from children and adults whom can not communicate verbally. Rather than asking the patient “which is better”, objective tests are used which require no responses from the child. Computerized testing and a diagnostic procedure called retinoscopy can be used to determine an accurate prescription for young children. Drops can often improve the accuracy of these procedures. Your child will also be examined for “lazy eye”, abnormal ocular development, and eye diseases.
Frequently, the examination takes only 15-20 minutes, and the vast majority of children enjoy their time at the office. Best results are usually obtained if the visit is scheduled when your child is usually at his or her best, by avoiding nap times or typically fussy periods.
Technorati Tags: eye exam, child, eye care, optometrist, pediatric
Categories: FAQ · Refractive issues · children · examinations
A: An optometrist who is “therapeutic” is trained and licensed to treat eye diseases and write prescriptions as needed, in addition to ascertaining the need for visual corrections such as glasses, contact lenses and refractive surgery. A therapeutic optometrist has completed eight years of college and postgraduate instruction leading to the Doctor of Optometry (O.D.) degree and the conditions they treat and manage vary by state.
An optometric glaucoma specialist is an optometrist that has gained training in addition to that of an therapeutic optometrist allowing him or her to treat patients with glaucoma. The glaucoma specialist can also prescribe oral medications in addition to the topical ophthalmic medications prescribed by the therapeutic optometrist.
Technorati Tags: optometrist, glaucoma, eye care
Categories: Eye Care · FAQ
January 25, 2008 · 1 Comment
A: Many conditions can contribute to dry eyes, including both your health and your, environment. Are you near any ceiling fans or heaters? Does your car’s heater or air conditioner blow directly on your eyes? Some medications, such as antihistamines, decongestants and diuretics can also contribute to dryness. Hormone changes, such as those attributed to pregnancy or menopause may also be a factor. Some people have a condition called blepharitis, where their lids become dry and flaky, this too can contribute to dryness. Other people may be suffering with “Sjogren’s Syndrome”, which is an autoimmune disorder where the mucous membrane glands are attacked causing significant dryness and discomfort.
Your optometrist can evaluate the source of your dry eyes and initiate a treatment plan. Dry eye syndrome is very common and can be successfully treated. In addition to eye drops there are many new solutions for the treatment of dry eyes that don’t require the use of eye drops.
Categories: Cornea · Eye Lids · FAQ · dry eye syndrome · examinations
Tagged: blepharitis, Cornea, dry eye syndrome, eye, irritation, sjogren syndrome
