New Research: Exercise May Reduce the Risk of Glaucoma

People who are doing moderate to vigorous physical activity may significantly lower their risk of glaucoma, according to research presented at the 121st Annual Meeting of the American Academy of Ophthalmology (AAO). Tseng et al from the University of California, Los Angeles (UCLA) reported a 73% lower incidence of glaucoma among the most physically active study participants, compared with the least active. 

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The researchers reviewed survey and pedometer readings from the National Health and Nutrition Examination Survey (NHANES), which has tracked the health and nutritional status of over 70 million adults in the United States since the 1960s. For each 10-minute increase in moderate-to-vigorous activity per week, glaucoma risk decreased 25 per cent.(1) This suggests that exercise plays a protective role, where people who exercise at a higher intensity (speed and steps) may decrease their glaucoma risk more, compared to people exercising at a lower intensity. 

These results correlate with a study showing reduced self-reported glaucoma incidence with each kilometer (km) per day run and with each incremental increase in speed in a 10-km footrace among 29,854 male runners followed for 7.7 years. (2)

However there are studies which contradict these results. A South Korean study of 11,247 people,  showed increased glaucoma prevalence for participants doing high intensity activity versus moderate activity.(3) South Korea does have a high proportion of normal tension glaucoma, where there may be a lower threshold for glaucomatous damage due to exercise-induced changes in eye pressure.

Care should be taken when interpreting these new findings until they are published in a peer reviewed journal. However the emergence of exercise as a potential modifiable risk factor in glaucoma is exciting, because most other risk factors are outside an indiviual's control. Moderate intensity exercise appears to be safe and likely beneficial for most people,(10) including glaucoma patients.

People with glaucoma, especially normal tension glaucoma, or advanced disease, should discuss exercise with their Eye Specialist. 

References:

1. Tseng, V., F. Yu, and A.L. Coleman, Exercise Intensity and Risk of Glaucoma in the National Health and Nutrition Examination Survey, in American Academy of Ophthalmology. 2017: New Orleans, USA.

2. Williams, P.T., Relationship of incident glaucoma versus physical activity and fitness in male runners. Med Sci Sports Exerc, 2009. 41(8): p. 1566-72.

3. Lin, S.C., et al., The relation between exercise and glaucoma in a South Korean population-based sample. PLoS One, 2017. 12(2): p. e0171441.

4. Society, A.P.G., Asia Pacific Glaucoma Guidelines. 2016, Kugler Publications: Amsterdam, The Netherlands.

5. Qureshi, I.A., The effects of mild, moderate, and severe exercise on intraocular pressure in glaucoma patients. Jpn J Physiol, 1995. 45(4): p. 561-9.

6. Wylegala, A., The Effects of Physical Exercises on Ocular Physiology: A Review. J Glaucoma, 2016. 25(10): p. e843-e849.

7. Natsis, K., et al., Aerobic exercise and intraocular pressure in normotensive and glaucoma patients. BMC Ophthalmol, 2009. 9: p. 6.

8. McMonnies, C.W., Intraocular pressure and glaucoma: Is physical exercise beneficial or a risk? J Optom, 2016. 9(3): p. 139-47.

9. Susanna, R., Jr., et al., Applications of the water drinking test in glaucoma management. Clin Exp Ophthalmol, 2017. 45(6): p. 625-631.

10. Garber, C.E., et al., American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Med Sci Sports Exerc, 2011. 43(7): p. 1334-59.

Dry Eye Assessment

Dry Eye occurs when there is inadequate tear film to protect the ocular surface. Symptoms include scratchy, gritty irritated eyes. Life expectancy, longer working careers, increased screen time, low humidity, metropolitan environment and diet are increasing the incidence of dry eye. Diabetes, smoking, contact lenses, eye surgery and medications can exacerbate symptoms. Mild dry eye can be annoyingly uncomfortable, and severe symptoms can limit activities such as work, socialising or travel, significantly reducing quality of life.

 Medmont Video Tear Film Analysis

Medmont Video Tear Film Analysis

Dry eye science is a growing area. New methods to diagnose the different types of dry eye, (Aqueous Deficient Dry Eye or Evaporative Dry Eye) are being developed, along with new treatments. We now have specialised tests and offer in-practice treatments. If you have dry eye symptoms we may be able to help you.

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Here is what a Dry Eye Assessment involves. We start with a questionnaire on your symptoms. This gives insights into your dry eye, and helps us measure improvements. Diagnostic tests include video Tear Film Surface Quality analysis. We use staining techniques for a microscope evaluation which includes assessment of the oil glands and eye lids. Blephasteam Heat goggle treatment is followed by lower lid margin cleaning and oil gland clearing.

At your appointment we will create a treatment plan for ongoing relief. This will often include drops and ointments, Omega-3 supplements and eyelid hygiene treatment.

If you have dry eye, or dry eye symptoms, please book an appointment to see us.

Visual Hallucinations are real

Charles Bonnet Syndrome (CBS) is the rather strange phenomenon of complex visual hallucinations in people with vision loss with no neurological or psychiatric problem. These experiences can be alarming for patients and their families - ‘Mum is seeing monkeys in trees’ will get our attention.

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A study into the prevalence of CBS was published in the Canadian Journal of Ophthalmology (1).  2,565 new  clients aged 40 years and older at a national low vision service in Canada were carefully questioned; 18.8 % of clients reported that they experienced hallucinations, forming visual images that they knew were not there. Perhaps surprisingly, about 15% of clients with only mild vision loss (BCVA between 6/6 and 6/17 in the better eye) also experienced hallucinations.

Similar rates of CBS were reported by people with AMD, glaucoma, diabetic retinopathy and other eye diseases, suggesting that it is vision loss rather than a specific disease.  

There was also no difference in the likelihood of reporting hallucinations in people aged older than 80 compared with those aged 40 - 80 years. More CBS was reported in females. The author suggested that this may have been due to a greater reluctance of males to report the condition.

Given the high proportion of CBS in people with even mild vision loss, it is a reminder for us to be aware that many low vision patients may be experiencing CBS. These people will benefit from reassurance that their experiences are not atypical and that they are not suffering from a mental health disorder.

(1) Gordon K. Can J Ophthalmol 2016; 51: 3

Macular Degeneration Trigger Enzyme Discovered

The discovery of a crucial trigger for dry macular degeneration (AMD) – an enzyme called cGAS – could lead to the development of a drug to prevent disease progression. 

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This discovery, at the University of Virginia School of Medicine, was a surprise. Drs. Jayakrishna Ambati and Nagaraj Kerur had determined that cGAS plays an important role in the body's immune response to infections detecting foreign DNA, but its role in dry AMD was unexpected. 

“It's really surprising that in macular degeneration, which, as far as we know, has nothing to do with viruses or bacteria, cGAS is activated, and this alarm system is turned on,” said Dr. Ambati. “This is what leads to the killing of the cells in the retina, and ultimately, vision loss.” 

cGAS may also be an alarm for other problems that warrant responses from the immune system, and may play important roles in conditions like diabetes, lupus and obesity. “Because the target we're talking about is an enzyme, we could develop small molecules that could block it,” said Dr. Kerur. “There are many drugs already on the market that target specific enzymes, such as the statins.” 

A drug to inhibit cGAS will take several years to develop. Researchers also hope to find a way to detect enzyme levels in patients' eyes, and determine when best to administer a treatment that blocks cGAS. “This is really precision medicine at the single-molecule level,” said Dr. Ambati.

The findings were published in Nature Medicine.

Advanced Glaucoma Training

Currently Claire is one of four optometrists completing Advanced Glaucoma Training with the University of Auckland. The course is designed to give experience in glaucoma management and collaborative care with ophthalmologists (eye specialists).

 Medmont Visual Field Results

Medmont Visual Field Results


Claire is authorized to prescribe glaucoma medications. This expanded scope for optometrists has been in place since 2013. Claire says “in our community with a high proportion of people over 65 years of age this is valuable. Prevalence of glaucoma increases with age.”
Planning is underway for Auckland District Health Board to involve optometrists in glaucoma management and care. This will be particularly helpful for us here in Warkworth; it will reduce the burden of travel to either Greenlane Eye Clinic, or Waitakere Eye Clinic.
The initiative is designed to reduce the waiting time for appointments and glaucoma is a condition which needs ongoing check ups.

Slowing Myopia - OrthoK Case Notes

Fitting children with hard contact lenses which they will wear while sleeping at night may seem like a big undertaking, but the outcomes
continue to impress us. From the first morning these children see massive improvements in their vision - one of the most rewarding
aspects to this work.
When we met Jack* he was 6 years old, an outdoors boy who loved to read, struggling to see the whiteboard at school. Jack’s Mum is
highly short-sighted (-9.00D myopic), and his dad is moderately short-sighted (-2.50D myopic). Jack’s first prescription in December
2015 was -1.00D.
Jack also had poor visual efficiency, a risk factor for becoming more myopic. The first step was a behavioural optometry assessment
and vision therapy to improve his binocular vision. This was successful, but his distance vision remained blurred.

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At the end of 2016 Jack got his first pair of glasses. To start he only wore his glasses a couple of times a week at school. Over a 6
month period, Jack’s vision got worse, by -0.50D. If he continued at this rate, by 18 years old his prescription could track towards -
11.00D increasing the risk of serious future eye problems (retinal detachment, glaucoma and maculopathy).
This year we have fitted Jack with custom made Ortho K contact lenses to wear while sleeping. This gives him clear vision the next day
once he takes out his contacts. Importantly, wearing these contact lenses can significantly slow down his myopia progression.
When we checked Jack after his first night wearing his contacts, he commented “I can see great” and his vision was 6/6 (equivalent to
20/20). He managed to take out his lenses solo on the second morning. There are more firsts; he was able to see his parents in the
back row of assembly when he won an award at school. His family report “we are so impressed with these lenses, Jack is really excited
to be able to see clearly and positive about the process.”
Jack will have follow-up checks every 6 months to monitor his vision. So far, after 2 months of treatment his vision has not changed at
all.
*name changed for privacy