Did you know? Two patients today asked me what 20/20 vision means. I suspect that every day other patients wonder as well, but don’t ask.The easiest way to think about 20/20 is that it means that the eye can see at 20 feet what the average, healthy eye can see at 20 feet. It would follow that 20/200 (poor) vision means that the eye can see at 20 feet what an average, healthy eye can see at 200 feet, or that an eye that sees 20/10 (exceptionally well) sees at 20 feet what an average, healthy eye can see at 10 feet.
Having 20/20 vision does not necessarily mean that your eyes are healthy. The presence of glaucoma or many other eye conditions may not affect central visual acuity until late in the disease. Healthy eyes, though, usually do see 20/20 or better.
If an eye does not see 20/20, it is up to the ophthalmologist to determine the cause. It is also important to test each eye individually.
Did you also know? The standard eye chart used by most doctors today is known as the Snellen Eye Chart, developed by Dutch ophthalmologist Herman Snellen in 1862.
There is a much higher concentration of vitamin C in the aqueous humor (the fluid in the front of the eye which bathes the cornea, iris, and lens) than in the bloodstream. For many years, some researchers have speculated that taking vitamin C could lessen the incidence of cataracts.
A new study from Sweden refutes that claim. Over the course of ten years, women who took vitamin C supplements had a higher incidence of cataracts than those that did not. Those on birth control pills and vitamin C had an even higher rate. The increase was not huge, but was significant.
This study and others show that until properly controlled studies are done, speculating on the benefit of vitamin supplementation often is fraught with errors, (and in the case of many purveyors of supplements, wishful thinking, misrepresentation, and fraud).
Many people claim that health savings accounts, such as those used successfully at Whole Foods Market, cannot work on a large scale. John Stossel reports that Singapore uses health savings accounts as the model for their national health care. Almost 2/3 of medical expenditures are controlled by the individual. As a result, healthcare costs are less than half those of France, where the state controls almost all expenditures.
John Stossel interviews John Mackey, of Whole Foods Market, who provides a tested alternative to the health care “reform” making its way through Congress.
Unlike Congress’s “reform”, which, of course, will do nothing of the sort, John Mackey’s Health Savings Accounts have been enthusiastically endorsed by his employees, have provided them with control over their health care spending, and have lowered costs.
The following video is part one of seven, which are all available by clicking on the You Tube logo in the corner of the screen.
Do you think more government is the solution to health care costs?
Think about the cost of education, military, highways, and health care, which are all virtual government monopolies. Costs which have skyrocketed, with questionable quality.
Now think about the rest of the economy. Computers, televisions, clothing, and for-profit medicine, such as lasik eye surgery. Costs have plummeted, and quality has increased exponentially.
This is what happens when people are free to buy and sell as they please. Natural incentives encourage innovation, price-shopping, increasing quality, and lower costs.
The following video explains succinctly, and clearly, how our government has mandated perverse incentives into the tax code and insurance laws which have created the monster which is today’s health care, and three simple, common-sense solutions.
Are these solutions discussed ANYWHERE in the proposed healthcare overhaul? Fat chance.
Thanks to Dr. Maloney for contributing to this fine video.
This is a superb video from the American Academy of Ophthalmology. You should pass it along (by clicking the share button) to anyone with diabetes or anyone with a family member with diabetes
Did you know? Patients frequently ask why it’s necessary to dilate the pupils during a complete eye examination. It’s simple, really. Imagine the difference between looking into a room through a keyhole, and looking in through a large window. If you really want to get a good view inside the room, the large window gives a much more complete view.
Similarly, dilating the pupil enables the ophthalmologist to view the entire back of the eye. What are we looking for? There are hundreds of things that can go wrong inside the eye, (many of which have no symptoms). We’re checking to see if everything is normal. We look at the optic nerve, the blood vessels, and the retina, including the central retina, called the macula. If you have a specific complaint, like floaters, or a family history of glaucoma, or blurred central vision, obviously we will pay particular attention to the part of the eye which is most likely involved.
Here is a diagram which shows the advantage of a dilated pupil. The diagram is incorrect, though. With a dilated pupil, and the proper equipment and technique, the entire back of the eye can be examined (including the periphery), not just the part shown in the diagram.
(courtesy of the National Eye Institute)
Did you also know? In 1823, a Dr. Purkinje was the first to ever look inside a living human eye, when he devised the optics to do so. It was not until 1850 that another ophthalmologist, Hermann von Helmholtz, invented the ophthalmoscope independently and publicized his device that other doctors finally were able to look inside the eye and more accurately diagnose its conditions. Read more about the history of the ophthalmoscope here.
Did you know? The average person has almost no idea how the eye works! When educating patients about their eye conditions, I routinely start from square one, and give them a quick overview of how the eye works. The simplest and most accurate explanation is that the eye is like a camera.Light enters the camera through its lens, is inverted, and lands on the film (or digital sensor), where it can be processed into a picture.
Similarly, light enter the eye through the cornea (the clear window) and passes through the lens, where it is inverted. The light then lands on the retina, which is like the film in the camera. The signals from the retina travel through the optic nerve to the brain, where they are processed into a picture.
(image courtesy of the American Academy of Ophthalmology, with permission)
Did you also know? The pupil of the eye is like the aperture of the lens. In dim light, a photographer opens the aperture wider, letting more light in. Similarly, the pupil enlarges in dim light, letting more light in. In dim light, the photographer will choose a more sensitive film (or increase the sensitivity of the sensor). Similarly, the retina gradually adapts to dim light by becoming more sensitive to light (think of walking into a dim movie theater.)
Did you know?Patients are routinely prescribed eyedrops for a variety of conditions, including dry eye, infections, glaucoma, and for post-operative care. Few patients, however, are given instructions on how to instill their eyedrops. When asked to demonstrate how they instill their drops, few patients are able to perform drop administration reliably, which means that they may be receiving inadequate medicine, or may be spending too much on drops because the drops don’t enter the eye on first attempt.
The sketch below shows proper technique. One stands in front of the mirror, pulls the lower lid down, and places one drop into the pocket formed. The drop does not need to be placed on the eyeball, and one drop is all that is necessary.
That’s all there is to it!
(image courtesy of American Academy of Ophthalmology)
Did you also know? Closing the eyes gently for a minute or two after drop instillation may help increase its absorption into the eyes and keeping the medication out of the bloodstream.
Did you know? Imagine a restaurant where you don’t pay for your food. Everyone else in the restaurant pays your bill. Imagine that none of the other diners pay for their food. You, and everyone else pay for their meal. Do a thought experiment as to what would happen to expenses at this restaurant. With everyone else paying for your food, you would likely indulge in the finest, most expensive food on the menu. As would everyone else at the restaurant. The restaurant would keep raising prices, as demand would keep rising. If all restaurants were forced to operate in this way, costs would explode, and dining would assume a greater and greater share of the nation’s economy.
Do the same thought experiment with haircuts. Housing. Automobiles. Computers. Televisions. It is obvious that costs would rise in each situation.
Medical Care.
Oops, that situation today exists for most medical care.
Two historical events provided the incentives for this situation. In World War II, wage and price controls (never a good idea) were imposed. Employers wanted to reward their employees in other ways, so the government mandated that health insurance could be provided tax-free. Thus began the link between employment and insurance, and the incentive for insurance to become bloated, providing for more than just catastrophic illnesses and accidents, like insurance was designed to do.
Second, Medicare and Medicaid were started in the 1960s to provide “free” health care for seniors and the poor, thus creating the situation like the restaurant above.
John Stossel, as usual, hits the nail on the head in this excellent video:
Did you know? Latisse® is the new prescription medicine for growing longer, thicker eyelashes. Patients are already coming to my office and asking for it. The aesthetician in my office has been using it for a number of weeks and already reports a noticeable difference in her eyelashes.
Latisse® was developed because of a side-effect of a commonly used eyedrop for glaucoma. I can always tell if these patients are using their drops because their lashes are thicker and longer! Allergan decided to reformulate this medicine into a liquid which can be applied to the base of the upper eyelashes. In their clinical trial of 278 patients, 79% of patients noted thicker, longer and darker lashes at week 20 compared to 20% using a placebo. The majority noted improvement after two months.
The eyelashes gradually return to their baseline appearance after discontinuing the medicine.
There is a theoretical side-effect of permanent darkening of the iris (the eye color), though this did not happen in the clinical trial, and is unlikely to occur if the medicine does not enter the eye. There is also the theoretical side-effect of reversible skin darkening, but this did not occur in the trial either. Did you also know? Allergan, the makers of Latisse®, also make BOTOX® and Juvederm®. I enjoy using all of these products in my practice, and my patients enjoy looking younger, with a natural appearance.
Did you know? For many years it has been controversial whether having cataract surgery could accelerate the development of advanced macular degeneration. Some patients have cataract surgery, and not long after, develop worsening of their macular degeneration. Patients, of course, will often blame the cataract surgery. (I have at least one patient who falls into that category). What confounds this logic, though, is that cataracts occur with aging, as does macular degeneration. Patients may experience macular degeneration worsening with or without having had cataract surgery.
At last a well-designed study has addressed this question. The Age-Related Eye Disease Study (AREDS) was conducted between 1992 and 2005 and followed over 8,000 eyes of over 4,000 patients. The study was designed to assess the effect of antioxidants and mineral supplements on macular degeneration. The study assessed the development of advanced macular degeneration and history of cataract surgery at six month intervals during the study.
The results showed that appromately 20% of the eyes underwent cataract surgery during the study. Of the eyes undergoing surgery, 6% developed severe macular degeneration. Of the eyes not undergoing surgery, 7% developed severe macular degeneration. The results of the two groups did not significantly differ statistically.
It can be safely said that modern cataract surgery in unlikely to be related to worsening of macular degeneration. Did you also know? The AREDS study originally found that their combination of zinc and antioxidants (now found in Ocuvite and others) modestly reduced the risk of progression for eyes with early signs of macular degeneration. The AREDS II study, ongoing now, is investigating the possible roles of omega-3 fatty acids, lutein, and zeaxanthin. It is also investigating if the dosage of zinc can be reduced and whether beta-carotene can be eliminated (for safety reasons in some patients).
Did you know? For many years it has been controversial whether having cataract surgery could accelerate the development of advanced macular degeneration. Some patients have cataract surgery, and not long after, develop worsening of their macular degeneration. Patients, of course, will often blame the cataract surgery. (I have at least one patient who falls into that category). What confounds this logic, though, is that cataracts occur with aging, as does macular degeneration. Patients may experience macular degeneration worsening with or without having had cataract surgery.
At last a well-designed study has addressed this question. The Age-Related Eye Disease Study (AREDS) was conducted between 1992 and 2005 and followed over 8,000 eyes of over 4,000 patients. The study was designed to assess the effect of antioxidants and mineral supplements on macular degeneration. The study assessed the development of advanced macular degeneration and history of cataract surgery at six month intervals during the study.
The results showed that appromately 20% of the eyes underwent cataract surgery during the study. Of the eyes undergoing surgery, 6% developed severe macular degeneration. Of the eyes not undergoing surgery, 7% developed severe macular degeneration. The results of the two groups did not significantly differ statistically.
It can be safely said that modern cataract surgery in unlikely to be related to worsening of macular degeneration. Did you also know? The AREDS study originally found that their combination of zinc and antioxidants (now found in Ocuvite and others) modestly reduced the risk of progression for eyes with early signs of macular degeneration. The AREDS II study, ongoing now, is investigating the possible roles of omega-3 fatty acids, lutein, and zeaxanthin. It is also investigating if the dosage of zinc can be reduced and whether beta-carotene can be eliminated (for safety reasons in some patients).
Did you know? Botox® has been a mainstay in non-surgical facial enhancement for over a decade, and has proven safe and effective. Every year we find more ways to use it (for example, to raise the corners of a downturned mouth, or soften the lines around the mouth). In the next one to seven years, expect to see up to three Botox®-like compounds approved for use in the United States.
The first compound likely to appear is Reloxin®, available now in Europe under the name Dysport, made by the Medicis Corporation. Also in the pipeline are Purtox®, by the Mentor company, and Xeomin®, by the Merz Corporation. It is expected that differences between the compounds will be relatively small. It will be interesting to note whether or not competition will result in a decrease in price. Did you also know? Ophthalmologists were the first to use Botox both therapeutically and cosmetically. It was first used to weaken the muscles in certain cross-eyed conditions as well as to weaken the muscles in a condition called blepharospasm, where affected patients involuntarily squeeze their eyes shut.
I first used Botox® 15 years ago for patients with blepharospasm. My staff members would ask me to treat their wrinkles with the leftover medicine. Quickly they told my patients, and now it is a large and rewarding part of my practice!
Joshua Silver, a British physicist, aims to make eyeglasses more readily available for poor people around the world. He has developed eyeglasses which can be adjusted by inflating or deflating a fluid filled lens. When the lens is properly adjusted, the adjusting syringe is removed and the glasses are ready to wear.
His glasses have been recently publicized in the Washington Post and on NPR. He states that the glasses cost $19 each now, but he hopes that when production is scaled up the cost will decrease to $1 each.
The glasses are limited in that they do not correct for astigmatism and at this point correct from -6 to +6 diopters. Also, they would not come as bifocals, I imagine.
I wish Mr. Silver all the success. As someone who regularly works in third-world eye clinics, I know that this is something which could be a great benefit to the truly underserved.
I am sure Mr. Silver has investigated and been approached by all types of distribution possibilities. I hope that various for-profit models are seriously looked into, since businesses using very small margins and very high volumes have been used to gain widespread distribution of everything from shampoo to cell-phones in third-world countries.
Also, the country of India has developed a model of private and charity eye care combined with low-cost lens manufacturing to bring cataract surgery to the poor.
Did you know? There is an online resource which enables you to test your color vision. The X-Rite company, which manufactures devices which insure color standardization between computer monitors, provides a color test on their website. The test is called the 100-hue test, and involves arranging tiles in order of their hue. It’s rather challenging, are you up to it? (the test requires registration). Find the test here. Did you also know? Except when suspecting optic nerve disease, ophthalmologists rarely test color vision, and rarely so extensively as with the 100 hue test.
Did you know? Famed Spanish composer Joaquin Rodrigo was born on this day in 1901. He is best known for his guitar concertos, which helped introduce the guitar into the classical repertory.
Rodrigo was blinded at age 3 from diphtheria, according to his biography. Diphtheria, while exceeding rare today, was common before the diphtheria vaccine was invented. Diphtheria causes a thick membrane to form over the mucous membranes, typically in the airways, which can cause death. It also can cause scarring of the conjunctiva (the membrane over the white part of the eye) and ulceration of the cornea.
Did you also know? Beginning in 1939 (until ?) Rodrigo was the head of the artistic section of ONCE, the Spanish foundation for the blind. ONCE remains today a powerful global force helping the blind integrate into society.
Did you know? For a number of years, San Diego–based Ophthonix has produced customized eyeglasses as well as an aberrometer/autorefractor to measure the eye’s wavefront characteristics and refraction. It is only recently, however, that a large-scale, well-designed, rigorous, double-masked study has been presented to show the effectiveness of these eyeglasses as well as the process by which they are made.
This paper is available on their website, here. It’s not light reading, but would be of interest to an ophthalmologist, optometrist, or optician. It’s small print, too, so I recommend downloading the pdf file and using your pdf viewer to enlarge the text.
The study was performed at the prestigious University of Illinois Eye and Ear Infirmary, and published in the Review of Optometry, October 2008 (not a peer-reviewed publication).
The study consisted of two phases. The first phase tested 83 subjects with their old glasses, new glasses prescribed by a regular refraction, and glasses made by Ophthonix (wavefront-guided iZon® lenses). Subjects wore each of the new glasses for two weeks, and neither subject nor experimenter knew which lenses were being tested.
A battery of visual function tests was administered. The iZon lenses performed the best on seven of nine parameters, and the difference was statistically significant on four of them.
A second phase consisted of testing 52 subjects. Each was given four sets of lenses: lenses made with a traditional refraction made elsewhere, a traditional refraction made at the Ophthonix lab, glasses made with a refraction from the Ophthonix autorefraction, and glasses made with the Ophthonix autorefraction with wavefront-guidance and their proprietary 3-layer lenses.
The results of the second phase can be summarized by “there is an ordered progression of visual benefits derived from the components of the lenses… the best overall visual performance was gained by coupling Z-view® refraction with a 3-layer lens iZon® lens design.”
It is notable that many of the visual tests in which the iZon® lenses excelled were ones which have real-world consequences, such as low-contrast situations (like driving at night), glare situations (like driving into headlights or playing golf on a sunny day), and tests called the Environmental Visual Acuity Test, which measured how much farther away subjects could read signs they encountered (the iZon® lenses provided a 20% improvement compared to a conventional lens), and the Low-Luminance Acuity Test (viewing dark letters against a dark background– like driving on a dark road at night–the iZon® lenses provided a 20% improvement vs. all other lenses.)
The study is also notable for it provides the first somewhat clear description of just what occurs in the production of iZon® lenses. Rather than correcting for wavefront aberrations, (which custom-Lasik surgery attempts), the iZon® lenses are said to optimize vision in this way:
iZon®Lens Structure (3-Layer)
The wavefront-guided iZon®Lens is a unique design, with a three
layer structure. The mid-layer iZonikTMmaterial is a photo-polymer that
is sandwiched between separate back and front lenses. All three lay-
ers are 1.6 index material. The correction for the iZon®Lens is derived
from all 2nd to 6th order aberrations of the eye as measured by the
Z-View®Aberrometer. The aberrations are analyzed and manipulated
by a proprietary algorithm—the second of two used in the iZon®Lens
process—to determine the best sphere-cylindrical fit for the back
surface. The iZon®Lens is wavefront-guided, as opposed to wave-
front-corrected. Wavefront-guided refers to the use of wavefront tech-
nology to incorporate all 2nd to 6th order aberrations in determining the
best sphere-cylindrical fit, as opposed to wavefront-corrected that
implies correcting individual aberrations. By utilizing a wavefront-
guided approach, the iZon®Lens is optimized and unaffected by gaze
angle shifts that could result with the programming required in a
wavefront-corrected design.
The key point of this paragraph is that “the aberrations are analyzed and manipulated by a proprietary algorithm to determine the best sphere-cylindrical fit for the back surface.”
It’s not clear to me if the front surface of the lens or the thin iZonik ™ layer sandwiched between have refractive properties, but this does indicate that the higher-order aberrations are not being precisely corrected for, but rather are being used to give a better sphere/cylinder correction.
It apparently works (for those 65% of the population who are candidates for the lenses) to provide crisper “high-definition” vision with gains in many visual measurements.
One finding lacking in this study was a subjective evaluation of the lenses by the subjects. Previous studies showed a very large preference for the iZon® lenses vs. conventional lenses.
As a final note, I have had a pair of iZon® glasses for over a year. My impression is that they provide crisp vision, but I don’t have a conventional pair made at the same time to compare them to.
I can say that the autorefraction obtained of my eyes by the Ophthonix Z-View® autorefractor/aberrometer is the most accurate autorefraction I have ever had. It wasn’t necessary to change a thing!
Also of note is that I have a small financial interest in the Ophthonix corporation.
Did you also know? Other companies are using other technologies to customize eyeglass lenses. One company promises “changeable-focus” lenses with no moving parts. Time will tell if this becomes a reality.
Did you know? Researchers are investigating a novel method to deliver medications to the eye. A study sponsored by the QLT Corporation placed medication for glaucoma in a small plug, inserted into the lower punctum of the eye. You have probably noticed these tiny openings in your eyelids which drain tears from the eyes into the nose. By placing a plug in the punctum, the drug within slowly dissipates. Some of the drug travels back upstream through the tears and into the eye. In this case, the drug, Xalatan, lowered the eye pressure for twelve weeks, and nearly as much as when given as an eyedrop. The study was not perfect (lots of patients dropped out) but it certainly tells us that this is a promising area which could lead to use for many ocular conditions. Did you also know? Many studies have shown that up to half of patients do not take their prescribed eyedrops for glaucoma. A drug-impregnated punctal plug could be a huge benefit for these patients!
Did you know? Ophthalmologists routinely inquire about a family history of glaucoma, as it has long been known that glaucoma can run in families (the exact genetics are not known for most glaucomas, though). A recent study published in the British Journal of Ophthalmology compared the eye pressures of identical twins and non-identical twins. (Twin studies are a classic way of determining the role of genetics vs. environment). The study determined that genetics explained approximately 2/3 of the variability of eye pressure, while environmental factors explained approximately 1/3. This is a remarkable finding. Choose your parents well!
Did you also know? If you have a family history of vision loss from glaucoma, this study provides more reason to see an ophthalmologist at regular intervals, and remind your ophthalmologist of your family history.
Did you know? A study published in the August 2008 issue of the American Journal of Clinical Nutrition showed that eating oily fish (like salmon) more than once a week may lower the odds of developing severe macular degeneration by 50%, compared to those who eat oily fish less than once per week. The same study showed that those who consumed the most fish reduced their odds by 2/3. This study did not address the use of fish-oil supplements, so do yourself a favor and enjoy the real fish!
Did you also know? These results are similar to a study I mentioned last year, published in the Archives of Ophthalmology.
Did you know? Today is the anniversary of the birth of Ray Charles! (Sept. 23, 1930-June 10, 2004) This musical legend lost his vision at around age 5. Unfortunately, sources disagree on the cause of his blindness, and according to a 60-Minutes interview, Charles himself was not sure of the cause. Most sources say he had congenital glaucoma. This is a disease where the drainage system of the eye does not work properly, leading to high eye pressure, optic nerve damage and vision loss. Other sources say he may have had trachoma, which is an infection spread by flies, which can lead to severe scarring across the cornea, the clear window on the front of the eye.
Did you also know? Charles was not discouraged by his blindness. In his 60-Minutes interview, when asked, he states: “Why? About what? When you are blind, I think you probably only lose maybe 1/99th of what life is all about…” In the same interview, producer Quincy Jones recounts:
The only time where he ever appeared to have any kind of handicap was when a beautiful woman was in the room, then he started walking into walls and so forth. …‘Can I help you Mr. Charles?’ Jones says the sympathetic women would say. …He’d get real blind, you know, when the pretty girls were around.”
Jones further states that Charles sound was “darkness converted into light.” How appropriate!
Did you know? Puerto Rican-born singer Jose Feliciano was born blind from congenital glaucoma. Congenital glaucoma is a rare condition where the drainage system of the eye does not function properly, leading to high pressure in the eye and damage to the optic nerve. When this occurs around birth, the eyes sometimes enlarge leading to an unusual appearance. Even with modern treatment, usually involving surgery and medications, the prognosis for this condition is guarded.
Did you also know? In 1967, Jose Feliciano traveled to England for a concert tour. Authorities would not allow his guide dog into the country (due to rabies laws). Later, he wrote the song, No Dogs Allowed.
