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

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).

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Ortho – what?  Orthokeratology is a non surgical procedure used to correct the refractive error of the eyes.  Basically you sleep every night with a specially designed Orthokeratology lens to reshape your eyes’ cornea (front surface of the eye).  In the mornings when you wake up, the lens is removed and you have normal, clear sight for the the rest of the day.  At night, just before bedtime the lens is inserted into the eye again to maintain the shape for the next day.

For most people this sounds a bit far fetched, but believe me it works.  I have corrected my wife's vision, she was a –4.00D myope, for the past 11 years using Orthokeratology lenses.  Unfortunately only about 5% of the world’s Optometrists offer Orthokeratology as a procedure in their practices and so most people are blissfully unaware of this correction method.  If you Google the words Orthokeratology, Ortho-K, OK, CRT, Corneal Refractive Therapy, you will find a surprisingly high amount of web sites providing information about Ortho-K, yet somehow it still manages to fly under the radar of most spectacle wearing people.

Orthokeratology received its FDA safety approval in 2002 for the correction of Myopia up to –4.00D.  Since then many manufacturers of Gas Permeable contact lenses have pushed the boundaries of what is possible to correct with Ortho-K lenses.  With current technology, Orthokeratology can correct Myopia up to –10.00, Hyperopia up to +5.00D and low amounts of Astigmatism.  One Ortho-K lens supplier, Global Ortho-K Vision (GOV), also has multifocal designs that provide similar vision to what soft multifocal contact lenses provide. For people who had LASIK refractive surgery done but still can not see too well, GOV also patented a Post LASIK Orthokeratology lens.  With this lens it is possible to rehabilitate most post LASIK corneas by smoothing out the uneven LASIK treatment zone and then correcting the remaining refractive error to help improve the overall visual acuity of the patient.

Video of Orthokeratology lens on the eye ...

As the poor economic state of the the world forces people to tighten their belts we see more and more people starting to push the boundaries of rules and regulations to try and save a bit of much needed money.  Optometry patients are no exception to this.  

In no place do we see this phenomenon more than in the non-compliance of frequency replacement contact lenses. Most notably the Acuvue brand wearers.  All Acuvue soft contact lens products are registered two-weekly replacement contact lenses but frighteningly most contact lens wearers will wear their Acuvue soft contact lenses for between 4 to 6 weeks!

Sadly, some of the fault lies with the Optometrist who do not explain the frequency replacement schedule and the risks of not following the schedule adequately to their patients.  This however should now be rectified by the Consumer Protection Act that was introduced in South Africa on 31 March 2011.  The CPA laws are designed to prevent businesses that engage in fraud or specified unfair practices from gaining an advantage over competitors and may provide additional protection for the weak and those unable to take care of themselves.  The CPA under Section 41 deals with false, misleading or deceptive representations when marketing or promoting goods or services. This section prohibits the making of false misrepresentations about the standards, quality or characteristics of goods or services. It also forces suppliers to disclose all relevant facts that relate to the above mentioned features.  Under this section a failure to disclose the correct replacement frequency to a patients can be interpreted as a breach of this law and can potentially land the Optometrist in very hot water!

To further highlight the risks of non compliance with wearing soft contact lenses I would like to quote a recent article from Contact Lenses Today in which Dr Loretta B. Szczotka-Flynn wrote the following in a research review of contact lens induced complications:

"Dr. Kathy Dumbleton and colleagues at the Centre for Contact Lens Research in Canada recently reported a significant association between non-compliance with contact lens replacement and contact lens related complications. They assessed surveys from 501 silicone hydrogel lens wearers from seven eyecare practitioner's offices regarding lens wear and any lens related problems in the preceding 12 months. About half of their respondents wore 2-week replacement and about half wore 1-month replacement silicone hydrogel contact lenses.

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It’s Sunday night and we arrived in New York City.  We are on the first leg of our journey in the USA on our way to the Vision by Design congress.  Chris Eksteen and I have been invited to present a paper on advance Orthokeratology at the Vision by Design congress which is the annual academy meeting of the Orthokeratology Association of America.

Arriving at the Kennedy Airport after a 22hour flight via Dubai from Cape Town, we took the Sky train to the Best Western Inn in Jamaica, New York.

Settled in we decided it’s time to go and experienced the famed night live of New York City! After some friendly instruction from the receptionist at the Inn we took the Sky train to the New York Underground connection and then another 45 min trip on the Underground E train saw us arriving at 42^nd West Street.

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One of the most common visual side effects of Post LASIK patients is halo's and ghosting which is more pronounced during low light levels. These visual disturbances are called higher order aberrations (HOA).   In the opinion of contact lens fitters, many patients find relief of the higher order aberrations and improvement of their visual acuity when they wear Rigid Gas Permeable (RGP) lens fitted over the Laser treated corneal area. 

I recently read this research paper titled 'Changes in wave-front aberrations after rigid gas permeable contact lens fitting in post-laser in situ keratomileusis patients with visual complaints' published in Can J Ophthalmol. 2010 Jun;45(3):264-8.

The authors were Tan G, Yang J, Chen X, He H, Zhong X

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I have been invited to lecture on the subject of Orthokeratology at the October meeting of the Orthokeratology Academy of America called Vision by Design 2010 which will be held in Chicago, USA.

As part of the research and development team of GOV, lead by Dr. Tung Hsiao-Ching, I have been fortunate to be involved in a lot of the ground breaking developments in Orthokeratology.   Some of the interesting work included the rahabilitation of Post Lasik corneas with the use of Orthokeratology lenses and recently the correction of a Hyperopic Keratoconus patient with the use of overnight GOV orthokeratology lenses.

Doing the research for the lecture I found a wonderful article written by Dr Cary Herzberg, president of the OAA, called An Update on Orthokeratology, New technology and lens designs are expanding the applications for orthokeratology treatment which was published in the March edition of the Contact Lens Spectrum:

"This first decade of the new millennium could well be described as a decade of medical technological breakthroughs. Like the medical field in general, orthokeratology (or corneal reshaping) has seen its share of advances. Ten years ago many of us could not have anticipated all that would emerge as the modern practice of ortho-k progressed. Indeed, the process and tools that make up corneal reshaping today hardly resemble what I used in my ortho-k practice just a quarter of a century ago.

The purpose of this article is to present what constitutes a contemporary corneal reshaping practice as well as what may be in its future sights. Some of you may be surprised to learn how thoroughly ortho-k can meet the needs of a large percentage of your patient base.

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2010 is proving to be an exceptional year and to add to the excitement, I was lucky enough to attend the 34th British Contact Lens Association Clinical Conference (BLCA) in Birmingham, (May, 2010) . Besides gaining new clinical insights from the presentations, the BCLA proved to be a fantastic opportunity to network with international contact lens practitioners. More than 1000 delegates attended the conference from all over the world.  With two different lecture halls presenting different topics and a very impressive exhibition, there was not a single dull moment in the 4 days I spent at the conference.  More than 45 of the industry’s leading manufacturers supported the event at the exhibition, showcasing a multitude of contact lenses, instruments and related products.

Besides the presentations, I attended 2 clinical workshops:  Silicone Hydrogel Multifocals ... the when & how of fitting  and Orthokeratology lens fitting and troubleshooting. The clinical workshops were definably a highlight of my trip and are highly recommended for those who want to improve their practical skills in their specific area of interest. The Silicone Hyrogel Multifocal workshop exposed the new developments in this area and I am particularly excited about the new CooperVision Biofinity® Multifocal that is due to be launched in the near future. This lens utilizes the principles behind their Balanced Progressive™ Technology, which has been very successful with the Proclear Multifocal lens and will become available in the in the very popular Biofinity material.

To add to an already awesome itinerary, I was also fortunate enough to visit Cooper Vision in Hamble and was taken on a tour of the manufacturing plant as well as the distribution warehouse. This proved to be an absolutely amazing experience and really gives one a fantastic insight into differences in contact lens designs and curing processes. The automation and quality control technology is far more advanced than I ever imagined.  It is no secret that the UV curing process of Biofinity has been extremely successful and the demand for this product has grown exponentially since the launch of the Biofinity Toric.

I was also fortunate enough to witness the manufacture of the recently launched product Avaira.  Avaira is the latest addition to the CooperVision silicone hydrogel family in South Africa and offers excellent value.  Visiting the distribution warehouse enlightened me on the logistics that are involved in offering such a wide range of products and grew my appreciation for the availability of products such as the Proclear Multifocal Toric XR so much more.

The BCLA conference is the largest annual international event dedicated to contact lenses.  I can highly recommend it to any contact lens practitioner that would like new insights into world class research, education and information on all aspects of contact lenses, and the anterior eye. My trip to the BCLA is defiantly a highlight in my Optometry career!

Bausch + Lomb (B+L) announced the launch of Biotrue multi-purpose solution across the U.S. Biotrue multi-purpose solution is bio-inspired to work like the eyes to help lenses stay clean and moist throughout the day, according to the company.

B+L reports that Biotrue was developed following intensive study on how the eye naturally works to clean, hydrate and keep itself healthy. It has exceptional disinfection properties, and is formulated to work like the eyes with three bio-inspired innovations. Firstly, it is pH-balanced to match healthy tears, helping to maintain the eye's natural condition and enabling optimal activation of Biotrue's dual disinfectants. In clinical trials 81% of patients who tried the solution said it felt like their natural tears.

The second innovation noted by the company is the use of hyaluronan, a natural lubricant found in the body and in the eye. This helps attract water to envelop lenses in a moisture-rich cushion and to stabilize the tear film and reduce friction. Even after 20 hours, a high level of hyaluronan has been shown to remain on both hydrogel and silicone-hydrogel lenses, helping to provide all day comfort. The third innovation is how Biotrue keeps certain beneficial tear proteins active longer. It surrounds and protects lysozyme, a protein found in tears, helping to maintain its natural antimicrobial activity and prevent denaturization. Additionally, Biotrue lifts and dissolves denatured proteins.

"By studying the eye, we're able not only to observe natural processes that have been proven evolutionarily, but we're also able to develop health care solutions that work with the body, rather than interfering with it," said Mo Merchea, Medical Affairs Manager, North America, Vision Care at Bausch + Lomb. "Biotrue uses the science of the eye itself, and therefore the lens care solution is optimally designed to work within the eye."

Biotrue exceeds FDA/ISO stand-alone procedure for disinfecting products and, according to information supplied by the company, it also has been tested against a broad range of bacteria and fungi, collected from clinically worn lenses, lens cases and infected eyes. It achieves consistently high log reductions against staphylococcus aureus, MRSA and fusarium solani and is also effective against acanthamoeba cysts and tryphozoites.

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Last month the family headed off to Mozambique for a two week vacation at the sea.  Our favoured destination is Ponta do Oura, which is the most Southern town on the Mozambique coast and a well know tourist attraction for Scuba divers all over the world.

Besides enjoying the tropical sun filled days, sea temperatures above 25 degrees Celsius , delicious Mozambique cuisine like pãozinho (pronounced pow-zing-yo or pow for short, which is a Portuguese-style bread roll), clam soup, Portuguese peri-peri chicken and LM prawns the main attraction for scuba divers are the pristine coral reefs.

Well known reefs like Doodles, Crèche, Checkers, Aquarium, Steps and Bass City play host to a wide variety of tropical fish like Lion or Devil fire fish, Stone fish, Potato bass, Two striped clown fish, Pipe fish, Paper fish, hundreds of different types of Butterfly, Angel, Wrasse, Moray eels, Goldies, Snappers, etc, etc. 

 

On fortunate days you can also be treated to Dolphins, Whale sharks and Leatherback Turtles.

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Intrastromal rings or Intacs broke into the ophthalmic market with a big bang and was hailed as a savior surgical procedure for Keratoconus patients.  The idea is to implant two semi circular rings into the tissue of the cornea on opposite sides of the keratoconus ectasia (protrusion of corneal tissue).  The mechanical effect of the Intact rings is to stretch the corneal tissue and in the process flatten the ectasia point of the Keratoconus.

Unfortunately the surgery outcome of the Intrastromal rings hasn't been as good as expected and very few patients achieve normal functional sight after the procedure.  Another complication is post op infections of the procedure as highlighted on this case study.

A 20-year-old woman presented with photophobia, decreased vision, and pain 11 days after uncomplicated implantation of intrastromal corneal ring segments (ICRSs) for keratoconus in both eyes. Bilateral corneal stromal infiltrates were noted at the site of ICRSs implantation. The patient was started on frequent topical fortified antibiotics in both eyes. Despite aggressive medical management, stromal infiltrates progressed, necessitating removal of ICRSs from both corneas to control infectious keratitis and melting of cornea.

Cultures obtained at the time of initial presentation yielded Streptococcus viridans. Patient responded well to the treatment and was left with stromal scars in both corneas.

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One of the key active ingredients used in the production of the product has been discontinued and we have been unable to source an alternative option.

• Bausch & Lomb Conditioning Solution and Concentrated Cleaner was discontinued
• Customers are being transitioned to  Boston Advance Cleaning Solution and Boston Advance Conditioning Solution