Contrary to what appears to be in much of the general public's opinion, contact lenses and in particular soft disposable lenses, as well as contact lens solutions, are not all the same and they are certainly not interchangeable.  The contact lenses have very different fitting characteristics as well as differing chemical properties.  The solutions used in caring for these contact lens products absolutely differ in their chemical reactions.  These chemical interactions are important when considering the solutions to be used to care for these products.

 

Soft contact lenses are categorized into four groupings for purposes of evaluating effects of accessory products upon the lens material. Lenses with less than 50 percent water content are considered to be "low water" and the others are "high water." Less reactive surfaces are termed "nonionic" and more reactive materials are labeled "ionic."   The groups are as follows;

 

Group 1  Low water, non-ionic

Group 2  High water, non-ionic

Group 3  Low water, ionic

Group 4  High water, ionic

 

Understanding the performance characteristics of each of these groups coupled with a deep understanding of fitting issues, physiological concerns, oxygen transmission necessities, and optical requirements, are all considered to ensure a proper contact lens for an individual.  Solution products also need to be carefully selected.  They must be compatible with the lenses that are being worn as well as compatible with the individual's own body chemistry.

 

All to often, as a doctor, I see this scenario.  "My friend is wearing "brand X" contacts and he says that is the best, so I want that one."  Or "I saw this new fantastic contact lens advertised on TV and I think that one is the one for me."  Or the scenarios that truly disturbs me, "Since I am on a very restricted budget, which contact lens is the cheapest?"  Also, "I was at the supermarket and solution "X" was on sale so I switched to that one."  Although I am sensitive to cost concerns, my first duty is to those two priceless, irreplaceable eyes, and not the budget allotted for contact lenses and the associated solution products.  I would much prefer to see an individual not wear contact lenses because they can't afford it, than to wear the wrong lens just because they can afford it.  Sight is a very precious and priceless gift, and to risk this over any of the above reasons, in my opinion, is just wrong.  The proper fitting of lenses and associated solution products should be a decision left to the professional who is trained and experienced in such matters.  When done this way, the chances for the best possible outcome have been maximized. 

 

One of the items in this particular newsletter is a study that looks at the interaction of contact lens solutions with specific contact lenses and the resulting problems.  I applaud the efforts of these researchers and hope to see more of these types of studies done in the future.  This type of information is very beneficial to the public.

In a recent lawsuit, Mark Schiffer was awarded $7.25 million dollars for developing a corneal ectasia as a result of his LASIK surgery.  This, to date, is the highest dollar amount awarded for any type of LASIK malpractice case.  In this particular case, there were supposedly some pre-operative warning signs of symptomless keratoconus, that were not diagnosed.  This resulted in this ectasia developing and ultimately requiring a corneal transplant.  I have personally provided care for LASIK-induced ectasias, and I can tell you that the visual quality as a result of these ectasias can be rather debilitating.  Mr. Schiffer is thirty-two years old, so this likely means a rather lengthy number of years that he will have to endure poor vision.
 

A recent study looked at four commonly used multipurpose solutions and their effect on symptomless, adapted daily-wear soft contact lens wearers.  The solutions examined were; Optifree Express (preserved with Polyquad), ReNu MultiPlus Multipurpose (preserved with polyhexamethylene biguanide [PHMB]), Solo-Care Plus (PHMB), and Complete MoisturePLUS (PHMB).  The contact lens groups that were tested were Group 2 (high water non-ionic) and Group 4 (high water ionic) soft hydrophilic or silicone hydrogel lenses.  Findings of corneal irritation increased significantly in Group 2 contact lens wearers using the PHMB based systems.  This effect was the worst in the group using the silicone hydrogel lenses and the Complete MoisturePLUS system.  The least problems noted were in the Group 2 lenses using the Optifree Express.  Unfortunately, the patient's symptoms did not necessarily correlate with the objective findings.  This means that a patient can be symptomless, yet still have this type of corneal irritation.

As of July 29th, 2005, after the Senate unanimously approved bill S. 172.  Cosmetic contact lenses for just decorative purposes will join the ranks of prescription contact lenses, and will now be Federally regulated as medical devices by the FDA.  Since 2003, the FDA has issued warnings to the public about the risks of these devices based on the reports of corneal ulcers, but now the law will hopefully curtail the blatant disregard of risks that beauty shops, gas stations and convenience stores are exposing the public to, by selling these medical devices to anyone wishing to purchase them.

A recent study looked at the mechanics for diagnosing Dry Eye Syndrome.  Two common tests used for diagnosing Dry Eye Syndrome are the Phenol Red Thread test and the Schirmer's Test.  In this study a Dry Eye questionnaire was administered in an interview process.  The two objective tests were then given to the study group.  The results of the study showed very poor correlation between the questionnaire and each of the objective tests.  The objective tests also did not correlate very well with each other.  This further underscores the difficulty in proper diagnosis of Dry Eye.  Proper treatment is very difficult to prescribe, if the proper diagnosis is not made.

In a recent survey, parents are almost three times more likely to have their child use sunscreen than to have the child wear sunglasses when playing outside on a sunny day.  This leaves the children at high risk for vision damage.  Among the problems for eyes with prolonged sun exposure, are macular degeneration and the early development of cataracts.  Only four percent of the parents surveyed said that they always made sure to hand their child sunglasses at the beach or before going outside.  One of the recommendations of the survey was to have parents lead by example.