Confused about sun exposure

[ilianandreev]

Hello guys,

I'm quite confused about sun exposure and influence on keratoconus .... one one side Dr. Brian Boxler states that:

"People with keratoconus should always wear sunglasses, in my opinion, because they protect the corneas from the harmful ultraviolet light of the sun, which has been shown to increase free radicals (cellular byproducts) that can accelerate keratoconus progression. — Dr. Brian Boxer Wachler"

On the other side I came across an article by Dr. Mercola which states that sunglasses should be avoided almost always because the human eye needs exposure to the full spectrum of light to control hormones, body function etc.

Here's link to the article:

http://articles.mercola.com/sites/artic ... myths.aspx

Now having in mind the sleep problems I have I'm wondering which is better, protecting my keratoconus or not ruining my cyrcadian rhytm from lack of light exposure.

Please share your opinion.

[Anne Klepacz]

Well the difference is that the first article is about people with KC and the second is about people in general. A lot of us with KC are more sensitive to light than other people, and our corneas are more vulnerable. So wearing sunglasses or something like a baseball cap makes life more bearable.

[ilianandreev]

Thanks you for the advice. Me personally can see better in bright sunlight conditions and have no light sensitivity despite my keratoconus. When I put sunglasses on most of the time my vision drops a bit so it's not very comfortable. I also use a higher brightness on my monitor as I'm a software developer and spend a lot of time in front of the PC, it makes me see the letters better as opposed to low brightness setup. So I'm not sure if I need to follow any advice or adjust brightness/sunlight levels when I feel I need to...

[Shelf]

Hi all - just for info, I only wear polarised sunglasses as it helps reduce glare and protects me from the sun. I have some very expensive sunglasses, but also use some from Halfords that cost £30 and are just as good as the big expensive brands - probably better as I don't care as much when I inevitably drop them.

However: I am very interested in this part of the question - "harmful ultraviolet light of the sun, which has been shown to increase free radicals (cellular byproducts) that can accelerate keratoconus progression"

Has it been proven that sun exposure is detrimental to those with KC as it can accelerate progression, does anyone know?

Corneal Cross-Linking (CXL) uses UV as a treatment to prevent keratoconus getting worse, so i am a bit confused.

the article mentioned is: http://www.allaboutvision.com/askdoc/keratoconus.htm

[ilianandreev]

Hi Shelf,

I've found the same statements on another study:

UV radiation may be related to kerato- conus. A large prevalence of the disease has been observed in countries with a lot of sun exposure and dry conditions for most of the year as prevails in Saudi Arabia,46 India47 and Israel.30 Prevalence is much lower in areas with less sun exposure and lower average annual temperatures, such as Finland,53 Denmark,64 the Urals,65 Minnesota,66 Japan32 and Macedonia.67 This may point to the envi- ronmental effect of excessive sun exposure of patients with keratoconus in this study. Although to our knowledge there is no inves- tigation of the effect of sun exposure on keratoconus in humans, it is a compelling possibility. Ultraviolet light is a source of oxidative stress and keratoconic corneas have a reduced ability to process reactive oxygen species, thereby resulting in oxida- tive damage27,68 due to reduced levels of anti- oxidants.69 This process triggers a cascade of events, such as an alteration of various corneal proteins, increased enzyme activities and apoptotic cell death, which leads to keratoconus.

So there may be some sort of link to UV exposure.... the more I read about this disease the more depressed and freaked out I get, it really affects my life very badly in terms of fear and anxiety.

On the bright side of things I also use sunglasses occasionally when its too bright (otherwise not). I live in a country where we get a lot of sun in the summer (Bulgaria) and throughout the years I've done nothing to avoid it because I see better in bright light conditions. I've got transplant on my eye and crosslinking on the other in 2008. Since then I haven't taken any special protective measures of the sun (except whearing sunglasses from time to time when its too bright). Now it's 2016 and I haven't seen any progression in my crosslinked eye. What does this mean? I don't know ... maybe the crosslinked cornea has become stronger and not vulnerable to UV anymore. But at the same time I'm afraid of what I've read ... I don't really want to wear my sunglasses all the time during the day, it's impairing my vision and depressing.

Also regarding crosslinking they use UV only for 15 minutes so it doesn't really matter I guess.

What do you think?

[Shelf]

I really don't know either - I had cross linking in both eyes last year.

But I do love the sun.

The reason I am asking is that I lived in Perth Australia from 2003-2008 and this is when my KC really progressed. It is also when i was in my early 30's, so I am not sure if the sun had anything to do with it or not.

What i can share with you is that Professor O'Brart did my cross linking and in his opinion UV light shouldn't impact the results post cross linking.... copied from an email i got from their office when i was due for my 1 year check up post Xlinking.

Professor O’Brart can see you in The Westminster Bridge Consulting Rooms, Ground Floor, Gassiot House, Westminster Bridge Road, London, SE1 7EH. He has also asked me to pass on that UV light will not affect the results.

[ilianandreev]

That's really great news Shelf! Something that I was suspecting too.

Btw do you wear any contact lenses?

[ilianandreev]

Hi Shelf,

Can you ask your doctor about this below (my doctor is not very experienced so I can't trust him unfortunately):

"Some studies indicate an abnormal processing of the superoxide radicals in the keratoconus cornea and an involvement of oxidative stress in the pathogenesis of this disease. Keratoconus corneas lack the ability to self-repair routine damage easily repaired by normal corneas. Like any tissues in the body, the cornea creates harmful byproducts of cell metabolism called free radicals. Normal corneas, like any other body tissue, have a defense system in place to neutralize these free radicals so they don’t damage the collagen, the structural part of the cornea, weakening it and causing the cornea to thin and bulge. The keratoconus corneas do not possess the ability to eliminate the free radicals so they stay in the tissue and can cause structural damage."

Does this mean oxidative stress from sun exposure can undo the effects of crosslinking ... just wondering...