Eye Care

Over the last 5 years Optometry has seen an explosion of new contact lens materials and designs.  It is now possible to fit almost anybody into a set of contact lenses if they so desire.  Lenses that were used mainstream ten years ago are now obsolete and have been replaced with superior materials which allow better oxygen transmissibility, bind better to your tear layer and have more advance optical designs. Somebody who failed to successfully wear contact lenses a decade ago will most like succeed now.

One of the areas in contact lenses which has seen the biggest increase in options is the Multi-focal contact lens group.  It is now possible to fit a big portion of the over forties group who suffer from Presbyopia with a pair of multi-focal contact lenses.  The freedom that these lenses offer to an active person is priceless.  Imagine being able to scuba dive and see your dive watch, or play a round of golf and be able to read the menu at the 19th without having to wear glasses.  As for the ladies the biggest advantage is applying make up and actually seeing what your doing!

So if your next eye test exam sounds like the one below, put your foot down and ask to be fitted with a pair of contact lenses.  Who knows, it might change your life! 

Frustration with fitting Multifocal Contact Lenses
by: baskotze

Personally I would choose Government.  Pay is better, hours are less, they have a good medical plan and they never go to jail.

Fitting Keratoconus

Keratoconus is a bilateral non-inflammatory corneal ectasia with an incidence of approximately 1 per 2,000 in the general population (1). The treatment of Keratoconus can be implemented by the use of spectacle lenses, contact lenses of various kinds and surgery.

In more advance Keratoconus cases where severe irregular astigmatism with resultant higher order aberrations are present, the use of Rigid Gas Permeable (RGP) lenses are indicated to restore the patients vision.  Unfortunately in some Keratoconus cases, contact lens intolerance develops and many patients consider Penetrating Keratoplasty (cornel graft). Lim, et al found that 83% of patients opting for Penetrating Keratoplasty was due to intolerance to contact lens wear (2).

However, Smiddy, et al found that 87% of the Keratoconus cases referred for Penetrating Keratoplasty to the Wilmer Institute at the Johns Hopkins Medical Institution could be successfully refitted with contact lenses.  Of the successfully fitted cases ultimately 31% needed keratoplasty after an average of 38.4 months of lens wear and 69% did not require Keratoplasty over an average follow-up interval of 63 months of wearing contact lenses.

Of the postoperative penetrating Keratoplasty eyes 60% had to wear contact lenses for best vision. Their conclusion was that Penetrating Keratoplasty can be delayed or avoided in many Keratoconus patients by using proper fitting contact lenses and further that Keratoconus eyes often need contact lenses after Keratoplasty (3).

Piggyback system

One option to improving the comfort of RGP lenses on Keratoconic and irregular corneas is to use a piggyback system. A piggyback system comprises of a soft contact lens first placed on the cornea and then followed by a RGP lens fitted on top of the soft lens.  With the birth of Silicone Hydrogel soft lenses and hyper DK RGP materials, piggyback systems have become a safe and viable option for vision correction of the compromised cornea. Tsubota, et al found that the oxygen pressure under piggybacked oxygen-permeable hard contact lenses was 95 +/- 14 mmHg after 5 minutes wear which was almost three times higher than the 34 +/- 14 mmHg when PMMA and low water-content lenses were used (4). Clare O'Donnell first reported on the fitting of a hyper-Dk piggyback contact lens system in Keratoconus and other irregular corneas in 2004 (5).

From everyone at Charl Laäs Optometrist we want to wish all our patients, clients, suppliers, friends and family a very blessed Christmas season.  May it be a period of rest, peace, love and family closeness.

We want to thank everyone who made 2011 a wonderful year for us all and hope that 2012 may bring you good health, fulfilment and joy.

Warmest regards

Charl, Basil, Johann, Nick, Ina-Marie, Jean, Ilse and Adre

“Don’t rub your eyes!” your mother used to say. “It’s not good for you”. But then who ever listened to their mother? It seems that in recent years, science have caught up with our mothers’ wisdom and a number of research papers are now clearly proving that rubbing your eyes can in fact damage your eye’s corneal health.

In our own practice we have seen many cases of keratoconus and healthy corneas distorted due to vigorous rubbing of the eye. The picture below shows the topography of an otherwise normal cornea that is chronically rubbed at the 6 o’clock position. The patient had best corrected vision of about 6/75 (20/25) at the time. Once her allergies were managed and she stopped rubbing the cornea her vision returned back to a normal 6/6 (20/20) after about 2 months.

Back in 1976, Karseras and Ruben wrote in their paper on the aetiology of Keratoconus that most keratoconus patients rub their eyes excessively. Eye-rubbing is considered the dominant aetiological factor in two-thirds of patients with keratoconus who progress to contact lens wear. Charles McMonnies in 2007 seemed to agree that abnormal rubbing may increase the likelihood of the development of some forms of keratoconus. He postulated that when vigorous knuckle-rubbing forces are located on the normal peripheral cornea, the thinner or weakened cone apex may be exposed to high intraocular pressure distending forces that may tend to promote ectasia.

Most recently Dr Alan Carlson wrote a comprehensive article on the dangers of rubbing the eye in patients with Keratoconus and post-LASIK:

In recent months LASIK refractive surgery providers in the United States came under fire from the US Food and Drug Administration. The concern is not related to the safety aspect of LASIK but rather to the incorrect perception LASIK advertising is creating in the US and internationally. If one takes into account the new Consumer Protection Act, South Africa adopted this year it is also very relevant to the South Africanmedical refractive surgery fraternity.

Recently, Denise Mann wrote the following article for Health Day highlighting the matter:

Agency giving practitioners 90 days to curtail inflated promises, missing safety info in ads

The U.S. Food and Drug Administration is once again cracking down on eye care professionals who make false safety claims and promises about the popular LASIK eye surgery.

The agency's Letter to Eye Care Professionals, issued this week, follows an earlier warning from May of 2009. In its latest salvo against deceptive, potentially harmful advertising, the FDA is now giving eye doctors 90 days to get in line and update any advertising or promotional materials that make false claims. After this time, the agency will take regulatory action, said FDA spokeswoman Erica Jefferson.

"It's about the false claims and not adequately providing consumers with information about the risks associated with the procedure," she said.

Image via Wikipedia

On November 8, a long-living botnet of more than 4,000,000 bots was taken down by the FBI and Estonian police in cooperation with Trend Micro, a leading Internet content security and threat management solutions company and a number of other industry partners.

In this operation, dubbed “Operation Ghost Click” by the FBI, two data centres in New York City and Chicago were raided and a command & control (C&C) infrastructure consisting of more than 100 servers was taken offline. At the same time the Estonian police arrested several members in Tartu, Estonia.

According to an FBI press release, Rove Digital founder Vladimir Tsastsin along with five other Estonian nationals have been arrested and charged with running a sophisticated Internet fraud ring that infected millions of computers worldwide with a virus and enabled the thieves to manipulate the multi-billion-dollar Internet advertising industry. Users of infected machines were unaware that their computers had been compromised—or that the malicious software rendered their machines vulnerable to a host of other viruses.

The botnet consisted of infected computers whose Domain Name Server (DNS) settings were changed to point to foreign IP addresses. DNS servers resolve human readable domain names like  www.charllaas.com or www.wikipedia.org to IP addresses that are assigned to computer servers on the Internet. Most Internet users automatically use the DNS servers of their Internet Service Provider.

A new sensation of lightness on the mountains

TERREX^TM FAST outdoor eyewear from adidas eyewear

Maximum function and minimum weight. The sports eyewear specialist adidas eyewear is extending its successful TERREX^TM range with a lightweight and narrowly shaped outdoor model, bringing optimal vision within the reach of extreme mountaineers and speed hikers, as well as those with a more leisurely approach to mountaineering. The TERREX^TM FAST is distinguished by its light weight, modern design, simple handling and first-class function - for ultimate peak experiences.

Light and fast.

These are key requirements for today's outdoor equipment. With the TERREX^TM FAST, adidas eyewear is now launching mountain sports eyewear that more than meets these requirements. Alix von Melle, a German extreme mountaineer, has tested the TERREX^TM FAST before its market launch: "When you're scaling high peaks, every gram counts. The TERREX^TM FAST is particularly light, and that makes it ideal for me. It's good to know that my eyes will be perfectly protected on my Broad Peak expedition this summer".

On Monday, 10 October 2011, 140 000 Census workers will start counting every single person in South Africa.

They will gather information about every person living at each address, including name, age, gender, race and other relevant data. Con artists will also be using this time as an opportunity to ‘steal’ identities and information for fraud purposes.

Important things to remember during Census 2011

• A Census worker will have a badge, a handheld device, a Census Bureau canvas bag and a confidentiality notice.
• Always ask to see their identification and badge before answering any questions.
• You do not need to invite the Census worker into your home and currently they are only knocking on doors to verify address information.
• Do not give your identity number, credit card, banking or financial situation information to anyone even if they claim to need it for the Census.
• Census workers will not be asking for donations.
• The company Acorn is not working with the Census Bureau and you should not share any information with anyone from Acorn.
• Census workers may contact you by telephone, post or in person at home. They will not contact you by email – do not click on links or attachments supposedly from the Census Bureau.

The only information that you are obliged to disclose is the number of people who live at your address.

It is important to share this information as it will be useful to you and your clients and will go a far way in preventing them from becoming victims of fraud or identity theft.

The outcome of many court cases rely on eyewitness identification, which in criminal law, is evidence received from a witness “who has actually seen an event and can so testify in court”.  In recent years many US Courts have noted on the inherently suspect qualities of eyewitness identification evidence, and described the evidence as “notoriously unreliable”.  In the United Kingdom, the Criminal Law Review Committee stated that cases of mistaken identification "constitute by far the greatest cause of actual or possible wrong convictions".

In many of these cases the persons providing the eyewitness accounts were convinced of what they saw.  So how is it possible that mistaken identities can occur from people who actually saw what happen? 

The Visual Pathway

The answer lies in the fact that vision is a complicated process that requires numerous components of the human eye and brain to work together.  The visual system is the most complex neural circuitry of all the sensory systems in the human body with the optic nerve alone containing over a million nerve fibres.

What humans perceive as vision starts with light rays being focused clearly and accurately on to the back of the eye on an area called the retina. Interestingly the image focused on the retina is inverted relative to the actual object.  This means that what we perceive as upright is actually focused upside down on the retina.