- Part 3

Today is World AIDS Day. Around 34 million people worldwide have HIV. 25 million have died from AIDS, 1.7 million of them in 2011. Just try to imagine what that number means. When I was a medical student and trainee ophthalmologist sight-threatening complications of HIV infection, such as CMV retinitis, acute retinal necrosis and progressive outer retinal necrosis, were fairly common, and many of our patients with AIDS ultimately died.

In Australia now we perhaps tend to complacency because most Australians with HIV are being treated with anti-retroviral therapy (ART), which stops viral replication and allows the patient’s immune system to function better, and significantly reduces the risk of passing the virus on. Australians with HIV can look at this disease now as a chronic illness that needs to be managed, and the sight- and life-threatening complications of AIDS are vastly less common than they once were.

But for many people worldwide, especially those in low- and middle-income countries, the reality is very different. Almost 3 ½ million children worldwide have HIV/AIDS, a devastating figure since ART would make mother-to-child transmission largely avoidable. In 2011 57% of pregnant women with HIV worldwide were treated with ART. The ongoing challenge is to increase that number, and to reduce the incidence of new infections.

The World Heath Organization (WHO) recommends a series of strategies to achieve this, including male & female condom use, testing & counselling for HIV and other STIs (sexually transmitted infections), ART for the infected partner in a relationship and after exposure to HIV (eg after needle-stick injuries in healthcare workers), harm reduction for injecting drug users, and the elimination of mother-to-child transmission of HIV.

Since Channel 7’s recent story on toxoplasmosis many patients have asked me about this condition.

Toxoplasma gondii is a protozoan parasite that can infect most mammals and birds, but which only undergoes sexual reproduction in cats. People can acquire the infection by eating undercooked meat (especially pork and kangaroo, but also beef, lamb and chicken), through contact with cat faeces (for example in sandboxes), through contaminated drinking water, or from pregnant mother to unborn child through the placenta (congenital toxoplasmosis).

In adults with a healthy immune system the parasite usually causes a self-limited, flu-like illness (although the eyes may be affected). In babies the result of infection depends on when during pregnancy the infection occurs. In the first trimester the infection may result in miscarriage, but when the baby survives it may have congenital toxoplasmosis syndrome, which can include retinal damage and visual loss, liver and spleen enlargement, small head (microcephaly), raised pressure in the brain, seizures and anemia. Because infections later in pregnancy are less likely to result in miscarriage, retinal effects are more commonly seen but changes are generally less severe.

It is very important that in order to avoid toxoplasmosis pregnant women avoid eating undercooked meat and eggs. You should avoid contact with cats and kitty litter. Infection with toxo before pregnancy doesn’t cause congenital toxoplasmosis syndrome, only infections during pregnancy.

In 1993 when I was a medical student doing a term in the USA at the Mayo Clinic I attended a lecture from a visiting professor who discussed his project, the development of a functioning retinal prosthesis, or Bionic Eye. At the time it seemed to sounded like science fiction, almost like an eccentric dream.

Well, move forward almost 20 years and this dream is becoming a reality. Last month in Melbourne Dianne Ashworth, who is affected by Retinitis Pigmentosa (RP), became the first person to receive a Bionic Eye, and Dr Penny Allen at the Royal Victorian Eye and Ear Hospital, the first surgeon to implant one.

This retinal prosthesis prototype was developed by Bionic Vision Australia, a consortium of researchers from the Bionics Institute, the Centre for Eye Research Australia (CERA), NICTA, the University of Melbourne and UNSW.

The research team is still at a very early stage in the development of this technology, but this historic pioneering Australian development gives hope to other people affected by conditions such as RP.

Last week I went to Hanoi, Vietnam, as part of a Sight For All (SFA) training program at the Vietnamese National Institute of Ophthalmology (VNIO). SFA is a charity that aims to reduce the impact of avoidable blindness, through programs in Australia and overseas. It was founded by Dr James Muecke AM, an Adelaide Ophthalmologist. James is one of those guys who seems to have more hours in his day than the rest of us.

The SFA program I was working with is focussed on providing further subspecialty training to three ophthalmologists at VNIO. A number of ophthalmologists from around Australia including me were asked to help and have been heading over for a week at a time to work with the three doctors in their clinics and operating theatres. In the past we’ve all had the opportunity to go abroad for further fellowship training in the UK, or Canada or the US, but in some ways it can be more effective to provide that assistance in the doctor’s own institution.

What I encountered was a group of dedicated, highly motivated doctors, and an optimism that for Vietnam the best years are ahead. It was a humbling experience seeing the enormity of the workload these guys face. And it was incredibly rewarding being part of a program that is achieving so much.

I saw equipment funded by Australian donations to SFA and the Fred Hollows Foundation being put to constant use, and the Vietnamese ophthalmologists have clearly found the involvement of the Australians very beneficial.

I encourage everyone to be involved in supporting one or both of these organisations in whatever capacity you can.

Sight For All

The Fred Hollows Foundation

Olympic fever has well and truly arrived at our house. The opening ceremony on Friday took my breath away, and not just because James Bond, New Order and the Specials were on the same bill. Danny Boyle and his team made a very moving tribute to the NHS and Great Ormond Street Hospital (GOSH) in particular. Seeing the tear-drop symbol of the GOSH Children’s Charity formed on the ground of the Olympic Stadium was an especially moving surprise.

Great Ormond Street Hospital wasn’t the first paediatric hospital in the world (that honour goes to the Hôpital Necker – Enfants Malades in Paris) but it was the first in the English-speaking world, established in London in 1852. It now receives 192,000 patient visits each year. I worked there as a Fellow in Ophthalmology almost 10 years ago, and that time still ranks as one of the most professionally and personally rewarding periods of my life. My second son was born in the nearby University College Hospital and Christened in the stunning, heritage-listed GOSH chapel, the apse of which is covered in the toys of sick children that have been prayed for.

Queen Victoria. It has had notable literary connections. Charles West’s friend Charles Dickens was an early fundraiser and board member, and James Barrie donated the royalties from Peter Pan to the hospital. When the Peter Pan copyright expired the UK Parliament extended it in perpetuity.

The hospital is a true tertiary referral centre, and in combination with the neighbouring Institute of Child Health forms the largest paediatric research centre in Europe. It’s motto, “the child first and always”, makes explicit the focus of the many expert and dedicated doctors, nurses and allied health professionals there who manage the very complex conditions that affect their young patients.

The tribute to GOSH and the NHS reflects the British people’s underlying appreciation for, and support of, the UK’s revolutionary experiment in universal health coverage, now more than 60 years old. The British have a great deal to be proud of, but it is hard to think of anything more important than this.

Now for Usain Bolt’s 100m and David Rudisha’s 800m …

…oh, and come on Aussie!

Once again this year the RANZCO Eye Foundation is running its julEYE eye health awareness campaign throughout July.

The Eye Foundation is the fund-raising arm of the Royal Australian and New Zealand College of Ophthalmologists (RANZCO) and the Ophthalmic Research Institute of Australia (ORIA). It is committed to funding research into vision loss, supporting and assisting eye care programs in disadvantaged communities at home and overseas, and raising public awareness about eye health.

In week 2 of JulEYE the Eye Foundation has focussed on the impact of diabetes and eye health. I have blogged about diabetes before. Almost half of all Australians with diabetes will develop retinal damage. In early stages when intervention can save vision there are usually no symptoms, so regular eye checks are essential to detect changes that would otherwise go untreated. With regular checks and timely intervention 90% of the vision loss caused by this disease is preventable.

In JulEYE the Eye Foundation is encouraging all Australians with diabetes to ensure that regular eye checks are on their agenda. Next week, week 3, the Eye Foundation will focus on Eye Safety.

Last month the first major review so far of outcomes from cataract surgery with the new femtosecond laser was published. It is an important paper, representing the experience of expert cataract and refractive surgeons adopting this new technology in an advanced Australian surgical facility. The first 200 surgical cases performed by 6 surgeons were reported.

What did they find? Well, contrary to initial presumptions made and claims propagated on behalf of the technology, the complication rate for surgery actually went up slightly. This shouldn’t really be a surprise. The adoption of any new surgical technology or technique is accompanied by a “learning curve” as surgeons adjust to a new way of doing things, sometimes with unexpected differences in the course and outcome of an operation. These surgeons rapidly adjusted, but cataract surgery with femtosecond laser was still not as “safe” (considered purely as a function of the complication rate) as standard phaco-emulsification surgery in their hands. It’s possible that in the hands of less experienced cataract surgeons the complication rate of femtosecond surgery may have compared more favourably.

However, we should remember that phaco-emulsification cataract surgery was accompanied by an even steeper learning curve in it’s early days. There may be changes to instruments, software and technique that alter the safety profile in the future, and there may be improvements in visual outcome that make a small increase in the overall rate of complications justifiable. But at the moment the evidence for this is lacking.

The authors of this study should be commended for submitting this paper. I look forward to further developments.

Paper:

SJ Bali et al. Early experience with the femtosecond laser for cataract surgery. Ophthalmology. 2012 May;119(5):891-9.

A number of medications in use have side-effects in the eye. Perhaps the best known of these is Hydroxychloroquine (sold as Plaquenil [Sanofi]), used to treat rheumatoid arthritis and systemic lupus erythematosus (lupus), which can cause macular toxicity when a large enough cumulative dose is received.

This month a Canadian cohort study presented perhaps the best evidence yet that bisphosphonates can increase the risk of inflammation in the eye. Bisphonates (eg Alendronate, sold as Fosamax [Merck]) are used for the treatment of osteoporosis and other pathological causes of bone fracture (such as multiple myeloma, Paget’s disease, hyperparathyroidism, bone metastasis).

Bone undergoes constant turnover and there is a dynamic balance between creation and destruction of bone. Osteoblasts are cells that lay down and mineralize bone, and osteoclasts are cells that break it down, or resorb it. Bisphosponate therapy has been shown to interfere with osteoclast metabolism and thus inhibit bone resorption.

In the Canadian study bisposphonate use was associated with an increase in the risk of scleritis and uveitis, two inflammatory eye conditions that can be associated with loss of vision. Etminan and colleagues looked at data for all 934,147 patients in British Columbia that visited an ophthalmologist from 2000 to 2007. 10,827 were first time uses of bisphosphonates. The risk of scleritis was 63 per 10,000 person-years in bisposphonate users compared to 36 in non-users, and the risk of uveitis was 29 per 10,000 person-years in bisposphonate users compared to 20 in non-users.

Although the increase in risk is significant, the total risk remains quite low and this is certainly not a reason to avoid bisphosphonates. Bisphosphonate therapy can save lives by preventing fractures that ultimately limit mobility, and based on this study there would be one case of uveitis for every 1100 patients taking bisphosphonates and one case of scleritis for every 370 patients. But it does mean that doctors prescribing Fosamax and other bisphosphonates, and patients taking them, should be aware of the association and seek urgent advice and assessment from their ophthalmologist if there is a suspicion of eye inflammation. There were 1.5 million scripts written for Alendrolate alone in Australia last financial year.

The good news is that early specialist intervention for both uveitis and scleritis can lead to good outcomes and can avoid any impact on vision.

Article:

Etminan M, Forooghian F, Maberley D. Inflammatory ocular adverse events with the use of oral bisphosphonates: a retrospective cohort study. CMAJ. 2012 Apr 2.

Last week was World Glaucoma Week. Glaucoma is usually a disease with no symptoms, and with no change in outward appearance of the eyes, and for this reason alone attempts to raise awareness are critical so that people at risk can be examined, diagnosed and treated.

Glaucoma in young children and babies is different. The initial signs and symptoms are normally apparent for parents, relatives, health care nurses and doctors to see, but because the disease is so uncommon these symptoms are often not recognized. How uncommon is it? The best Australian figures (MacKinnon et al, 2004) suggest 1 case for every 30,000 babies born, but there are variations between ethnic communities. In the UK amongst those less than 16 years old, 0.28/100,000 white British kids had glaucoma, whilst 2.46/100,000 kids of Pakistani origin had glaucoma. 1 in 2500 Saudi children has glaucoma, and in Slovakia a study showed that 1 in 1250 gypsy children had it whilst only 1 in 22,000 non-gypsy children had it. Some of the variation in groups is traditionally explained by increased consanguinity (close relations between families, such as marriage between cousins) and there are certainly differences in the frequency of important genes.

The most important signs of infantile glaucoma are the “classic triad” of tearing, photophobia (light sensitivity) and blepharospasm (screwing the eyelids closed). Tearing is very common in babies and is frequently caused by a blocked tear duct, but this is rarely if ever accompanied by photophobia and blepharospasm.

Infantile glaucoma can also cause the eyeball to be enlarged, most usually seen as an increase in the corneal diameter, and in most cases of infant glaucoma that I’ve seen this was the presenting sign. A normal newborn has a corneal diameter of around 10 – 10.5mm, and an increase in this, especially over 12mm, is highly suspicious. One of my patients had well-meaning admirers comment on her “beautiful big eyes”.

In almost all cases the treatment for childhood glaucoma is surgery. 70 years ago a San Francisco ophthalmologist, Otto Barkan, developed the first successful operation for infantile glaucoma, the goniotomy, by adapting a technique developed by an Italian surgeon De Vincentiis 50 years earlier. This is still one of the two most common treatments for this rare disease, substantially unchanged from his original description (the other procedure, trabeculotomy, is similar in many ways but doesn’t require a clear cornea). Although some children with recalcitrant glaucoma go on to require more invasive surgery, the majority of children with this disease can be managed very well with one of these techniques.

But only if they’re diagnosed.

Links:

Glaucoma Australia

Article:

MacKinnon JR, Giubilato A, Elder JE, Craig JE, Mackey DA. Primary infantile glaucoma in an Australian population. Clin Experiment Ophthalmol. 2004 Feb;32(1):14–18.

Last year a study published in the journal Optometry reported that Australian smokers are far more likely to know that smoking causes blindness than smokers in the US, UK or Canada. The investigators, who measured the health knowledge of smokers through telephone surveys, found that less than 10% of smokers in the US and the UK were aware of the link between smoking and blindness, but that in Australia, the only country of the 4 with a national awareness campaign about smoking and eye health, almost half of smokers were aware of the effects of smoking on vision.

The Australian campaign has obviously been very effective. The graphic photo of an eye with lids held apart with a speculum brings the message home, although the damage smoking does lies deeper, unseen in the photo, and half of Australia’s smokers still haven’t got the message.

Smoking is associated with a wide variety of eye diseases, both directly and through increasing the effects of a patient’s genetic susceptibility. The most important of these is macular degeneration (AMD). Smokers have 4 times the risk of non-smokers of developing the disease, and a smoker’s “second-hand” smoke increases the risk of family members developing AMD. There are a number of reasons for the increase in risk. Nicotine itself has been shown to cause over-expression of VEGF, a protein that stimulates new blood vessel proliferation, and has been shown to block PEDF, a protein that suppresses abnormal blood vessel proliferation. The proliferation of abnormal “new” blood vessels is what leads to the aggressive “wet” form of AMD. Tobacco smoke also reduces anti-oxidants, reducing the capacity of the macula to respond to toxic and other damage.

Cigarette smoke increases the risk of cataract development, dry eye syndrome, visual loss from thyroid eye disease, and recent studies have shown that it increases the risk and severity of ocular inflammation.

We need to encourage our smoking patients to quit for the sake of their eyesight, and support them when they try. The Federal government is currently fighting “big tobacco” in the high court, trying to get plain packaging through. Tobacco companies are worried about the loss of their brand identity. But to your eye, all cigarettes are branded the same.

Link: Quit Now

Article: RD Kennedy et al. Knowledge about the relationship between smoking and blindness in Canada, the United States, the United Kingdom, and Australia: results from the International Tobacco Control Four-Country Project. Optometry. 2011 May;82(5):310-7.

Dr Michael Forrest

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