Sunday, December 10, 2023

A Health Scare & A Very Different Type of Epidemic

Credit Wikipedia
 

#17,809

I rarely mention anything about my personal life in this blog, but this week I've had a bit of a health scare, and the warning signs are something that everyone needs to be aware of.  

Earlier this week, I began to see intermittent bright flashes in the corner of my right eye, and I suddenly developed a very large `floater' in my field of vision. 

Since eye flashes can be a sign of retinal tears or detachment (a true medical emergency), I quickly got myself in to see an ophthalmologist. Luckily, I'm far-sighted, and mine turned out to be from a more benign (age -related) cause. 

Many others, particularly those with myopia (nearsightedness) are not so lucky, as we are seeing an epidemic of retinal issues - even among young adults and sometimes even children - around the world. 

So much so, that in January of 2020, the American Academy of Ophthalmology published a report called Facing the Myopia Epidemic.  While rates of myopia are growing nearly everywhere, in Asia it has reached epidemic proportions, with Singapore, South Korea and Hong Kong reporting some of the highest rates in the world (> 80%).  

Although there are likely many causes (including genetics and too much screen time), a lack of time outdoors has been been linked to developing myopia, which has led Taiwan to institute a 2-hours-per-day of outside time for school students, which has slowed - and even reversed - their myopia epi curve since 2010.

Increased Time Outdoors Is Followed by Reversal of the Long-Term Trend to Reduced Visual Acuity in Taiwan Primary School Students
Pei-Chang Wu MD, PhD 1, Chueh-Tan Chen MS 2, Li-Chun Chang PhD 3, Yu-Zhen Niu PhD 4, Min-Li Chen PhD 3, Li-Ling Liao PhD 5, Kathryn Rose PhD 6 7, Ian G. Morgan PhD 8 9

Conclusions

Policy intervention to promote increased time outdoors in schools was followed by a reversal of the long-term trend toward increased low VA in school children in Taiwan. Because randomized trials have demonstrated outdoor exposure slowing myopia onset, interventions to promote increased time outdoors may be useful in other areas affected by an epidemic of myopia. 

A study in 2022 also found that the incidence of myopia increased during the COVID-19 pandemic.

The Impact of the COVID-19 Pandemic on Myopia Progression in Children: A Systematic Review
Monitoring Editor: Alexander Muacevic and John R Adler
Adrienne R Cyril Kurupp,1 Anjumol Raju,1 Gaurav Luthra,2 Mahrukh Shahbaz,2 Halah Almatooq,3 Paul Foucambert,2 Faith D Esbrand,2 Sana Zafar,2 Venkatesh Panthangi,2 and Safeera Khan2


Conclusions

Our systematic review aimed to study myopia progression's two most important risk factors - time spent outdoors and screen time during the pandemic. We found that children spend less time outdoors and sometimes no time at all due to strict home quarantine rules. Screen time increased significantly during this period, as children used electronic devices for recreation and online learning. Our review found that children used near-viewing devices such as smartphones and tablets more than other electronic devices such as televisions or personal computers.

We discovered that strict home quarantine, reduced time spent outdoors, and increased screen time are associated with myopia progression in children during the pandemic. Increased use of mobile phones and tablets was also associated with myopia progression. Therefore, educating children and parents on these risk factors and ways to tackle them is crucial. Educating them on reducing screen time, taking frequent breaks while using electronic gadgets, using lubricant eye drops to reduce dry eyes, and being encouraged to spend more time outdoors will help prevent further myopia progression. 


Having High Myopia (≤ −5 diopter correction) - even when corrected - is linked to a number of serious eye conditions, including Glaucoma, Cataracts, Retinal Detachment, and Myopic macular degeneration (maculopathy) as described in:

High myopia is said to occur when a person's myopia progresses until they need −5 dioptres (D) or more of spherical correction,1,2 although the definitions used to grade myopia are variable.

The prevalence of myopia is increasing globally.3 It has been predicted that, by the year 2050, high myopia will affect 9.8% of the global population; a total of 938 million people.4 The highest prevalence of myopia is seen in younger adults, particularly in urbanised East and Southeast Asian countries.2
High myopia
The definition of high myopia as ≤ −5 D was adopted as the World Health Organization (WHO) definition in 2015. A person who needs ≤ −5 D of correction has a visual acuity that is far worse than the threshold for blindness (–3/6 in the better eye).
Even when appropriate refractive correction is provided, myopia continues to place an individual at an increased risk of sight-threatening diseases, including5,6:
  • Glaucoma (open-angle)
  • Cataract (nuclear, cortical and posterior subcapsular)
  • Retinal tears which may lead to a retinal detachment
  • Myopic maculopathy or myopic macular degeneration
The incidence of these conditions is greatest in individuals with high myopia.
(SNIP)
Speaking to patients with myopia

It is important to make patients aware of these potentially sight-threatening conditions and that their risk appears to be proportionate their degree of myopia. Any sight loss should therefore prompt patients to seek a complete ophthalmic assessment.

Retinal detachment can affect any age group. Tell patients to contact an eye specialist immediately if they see flashing lights (usually seen in dim light in the temporal peripheral field) or floaters, or if they experience visual field loss. They must undergo an urgent dilated exam to exclude retinal tears and/or detachment.

Central visual loss as a result of advanced myopic macular degeneration can affect people of working age, so examine the macula at every visit. Individuals who develop CNV may be treated with intravitreal anti-VEGF therapies.11 Refer those with central visual loss for low vision assessment and/or offer hand-held magnifiers.

Because the risk of open-angle glaucoma increases in individuals with high myopia, it is wise to assess intraocular pressure and optic disc appearance at every visit. Assess visual fields if possible.

Ophthalmic workers should acknowledge high myopia as a significant cause of visual impairment and a risk factor for a number of sight-threatening conditions.

Key messages
  • High myopia is becoming more common
  • Even if the refractive error is corrected, the eye is at risk of visual impairment, particularly if the myopia is ≤ −5 D
  • Myopia increases the risk of open-angle glaucoma, retinal detachment, and myopic macular degeneration
          (Continue . . .)


Increasing outdoor time, taking breaks from our devices, and even using lubricating eye drops can help  reduce the risks of developing (or worsening) myopia. 

And given what is at stake, it is advice well worth heeding. 

While my own medical scare turned out to be nothing serious, my doctor and I have decided the time has come for me to have cataract surgery on my 70-year old eyes, which I'll undergo after the new year.  

As a result, I may miss a day or two of blogging in January and February, but it should make reading medical journals a lot easier after its done.