Bionic Eyes?
We continue to see amazing strides being made in eye care.
When I started practising optometry around thirty years ago, AMD was still known by the un-PC SMD (Senile Macula Degeneration). There were no vision enhancing treatments. Cataracts were still being removed with ICCE techniques. I thus cut my teeth fitting these newly aphakic patients ? often over ninety years old - into lenticular soft and RGP lenses. Believe me it was not easy. Dementia was often an issue: If they didn?t have dementia pre-op, they sometimes came out of the much longer surgery and general anaesthesia with dementia. Twenty-four hour post-op oxygen was one countermeasure that helped. Arthritis and lens handling issues were also a problem. Thus even though we didn?t have great Dk back then, extended wear was often a necessity. We nevertheless obtained amazing results with remarkable safety considering the low Dk/L associated with thick, high plus lenses.
Early IOLs were an amazing breakthrough but today?s phaco ECCE techniques with foldable lenses are by comparison even more miraculous. Accurate biometrics and algorithms allow for consistent, near-plano outcomes in around twenty minutes of sutureless surgery, under needle-free local anaesthesia.
Interestingly the viscoelastics that today help make these (and other) procedures so routine and successful, were developed in my hometown by Pretoria ophthalmologist Robert Stegmann of MEDUNSA, with whom I had some dealings back then.
We also nowadays have treatment options for some cases of AMD utilising anti-VEGF intraocular injections. It?s not uncommon for me to receive a few emails from retinal surgeons ?in between? injections. There are some amazing outcomes although of course these treatments are really only delaying the inevitable.
Technology continues to advance at an amazing rate and we may soon have true accommodating IOLs when Adventus Technology?s DV-Gel gets approved. This remarkable concept ? where the hardened contents of the cataractous lens are removed and replaced with a flexible polymer gel in the ?bag? - restores flexibility and thus functional accommodation. Great results have already been achieved in monkeys.
Another fantastic step to improve function in cataract sufferers and potentially presbyopes too.
Hurry guys my arms are getting shorter by the day!
Seeing is Believing: See With Your Tongue?
Another ingenious take on restoring vision is described in detail in this off the wall technology describing a process of ?seeing with your tongue?, sent to me by a colleague in South Africa. It basically captures a digital image and transfers this data to the tongue. The tongue (as you may recall from your first year anatomy and physiology) has a remarkable neural network that involves cranial nerves V, VII, IX, X & XII and is mapped very much like our retina is mapped in the occipital cortex. With training, mostly blind subjects or those with light perception only, are able to determine shapes and so on. Check out Brain Port Vision Technology?s remarkable device.
The bionic eye also continues to receive much publicity. Cochlear implants, referred to as bionic ears, have already provided amazing results and restored hearing to many deaf patients. The hope is that the bionic eye will do much the same. As I have said for years this is of course a much more lofty goal. Getting a microchip implanted into the retina that has the same resolution as the eye is one thing. Linking it to the millions of nerve fibres with correct mapping is a different kettle of fish. Early results are promising but at best they provide gross light and dark shape recognition of large objects in patients who had neither of these abilities. Something is better than nothing? It will of course take years, if not decades to achieve functional vision, if ever.
The Aussies believe they will have functional versions by 2020, but I doubt they will provide 20/20 vision.
No Gain?
For those with an interest in the ongoing corneal staining issues related to MPS disinfection the article Lipophilic versus hydrodynamic modes of uptake and release by contact lenses of active entities used in multipurpose solutions by Powell, Lally, Hoong & Huth, Contact Lens & Anterior Eye 33 (2010) 9?18 makes for interesting reading. Essentially what they found is that PHMB uptake was highest in ionic and non-Si-Hy lenses, while Aldox uptake was greater with Si-Hy lenses. They speculate that the slower desorption of PHMB (t1/2 = 120 min) versus Aldox (t1/2 = 20 min) may help explain observed higher staining around two to four hours with PHMB with some lenses. Similarly they suggest that clinical effects from Aldox would likely manifest soon after insertion due to the faster desorption of Aldox from the lens.
In another clinically relevant study, veteran researcher and toric lens expert Graeme Young & colleagues looked at posture and gaze direction effects on common astigmatic lens designs. In theory advanced stabilisation designs would likely be affected differently to prism ballast and peri-ballast designs. The study confirms this and such results should guide us in selecting the lens design most suited to our patients? vocational and recreation needs. It can make quite a difference in visual stability. Check out the abstract Toric lens orientation and visual acuity in non-standard conditions @ CLAE Volume 33, Issue 1, Pages 23-26.
Myopia Control: Myth or Legend?
As predicted and as you may have seen in the NZ Optics scoop (See NZ Optics, March 2010, page 3), CooperVision?s breakthrough MiSight myopia controlling daily disposable has quietly been launched in the Hong Kong market. During my time on CCLS council I well recall Nicola Anstice being the recipient of a CCLS grant and later an award for some of the clinical research for this concept. Auckland?s Optometry School academic John Phillips has patented this technology which has been his baby for the past decade.
It?s great to see some local research and the resulting product reach the market place, particularly with such world leading technology. I hope there?s more to come from the Department of Optometry and Vision Science at Auckland Uni.
Congratulations are in order.
I suspect that there will be a few people with their noses out of joint from not being first to market with myopia controlling soft lenses. We may even see some new patent wars but I hope not. I don?t believe such litigation is good for contact lenses in general and in fact may slow down technological advancement. That said I fully support taking to task anyone who steals intellectual property but the petty patenting of terms and concepts like ?extended wear? or ?myopia control? is taking it too far. By all means patent designs and technologies but general terms should not be allowed to be patented, or it all becomes a bit ridiculous.
From what I hear such myopia controlling lenses are best fitted at the onset of myopia ? potentially in the six to twelve year old group ? as it is at this stage of the development of axial elongation that this is most likely to be effective. Later onset myopia will apparently not benefit as much but I guess as with all things, time will tell. It will be interesting to see the real world clinical outcomes and level of myopia control achieved but in practice it will be difficult to quantify. Research shows that one could expect to see progression limited to around one third of ?normal? progression rates. I expect that in some cases we may see what appears to be greater myopia control and in others seemingly very little. We don?t have all the answers yet. This type of technology is set to evolve significantly over the next decade.
Bring it on!
There?s plenty of controversy surrounding myopia control and always has been. One would think it is something new the way it is being bandied about. Skeffington was onto it way back, as were many others.
To get some perspective I suggest you read this excellent article by Jerry Legerton & Brian Chou in Review of Optometry titled Myopia Regulation: Myth or Megatrend?
BIO
Speaking of bringing it on I am pleased to report that my Pretoria Bulls are currently top of the Super 14 log (with a game in hand) and by the time you read this we will have seen what Mercedes and the returning Schumacher can achieve in F1. I think it will be an interesting year. At least there?ll be something to make up for the inevitable damp and dreary Auckland winter after the driest summer I can recall in my time in NZ.
Disappointing
The April 2010 round of APC renewals will unfortunately herald the discriminatory forced retirement of a number of optometrists. Although a number would appear to be overseas registrations who do not practise in NZ, there will unfortunately be a number of top-class, experienced and dedicated NZ practitioners who will be caught in the crossfire. The majority are in their fifties and sixties who for various reasons declined to comply with the requirements of proving competence by completing a DPA or TPA course. This was one part of our battle against the board?s overzealous attempts to comply with the HPCA Act where we didn?t achieve all we set out to. That said, there are in fact certain competence-proving steps that affected practitioners can take to ensure compliance ? as a last resort ? to retain the ability to practise in the future.
Affected individuals should contact me and I?ll fill them in on the details, which at the end of the day seems to be an acceptable and less onerous solution to the problem.
Never-the-less I still find it an insult to these respected professionals. The lack of a grandfather clause is contrary to many other developed nations. Instead of enhancing patient safety and outcomes this forced retirement of skilled, experienced professionals may in fact lead to reductions in quality, service and safety.
One can review a number of my columns to see some of the history relating to the HPCA Act and Board registration saga. I don?t wish to waste space with a major rehash of the issues that are now largely historical in nature. October 2004 and November 2004 are examples and use the archives or site specific searches and keywords to find more.
More?s the pity it had to be like this?
