post-LASIK nerve damage + scleral failure

[multiplier]

Ten years after LASIK, I've still been having issues with dry eye and photosensitivity, so I flew from VA up to MA and met with the folks at Boston Foundation for Sight this afternoon.

Unfortunately, sclerals don't seem to be the silver bullet for me. They felt uncomfortable in my eyes and didn't improve the dryness noticeably. After several hours of testing, the docs concluded that dryness, per se, was not actually the source of discomfort all these years.

Instead, the problem is a very sensitive pair of eyes which have been made worse by having the nerve cut during LASIK. I am mainly aggravated by wind, dry air, sunlight and glare. My eyes feel like a "raw wound". The images taken from their testing revealed nerves that looked fragmented, but I don't really understand all the ramifications.

For me, the sensation is almost a mental one - I feel disoriented and distracted, and my eyes feel 'tight'. I had always associated all this with dry eye, but my Schirmer's test revealed only moderate dryness.

Back in the days of wearing contact lenses, the lenses always felt uncomfortable, dry and irritating, and LASIK clearly trigged a worse problem. The issue for almost a decade has been describing all this to eye doctors because the problem seems vague and abstract. 95% of the time their answer is: "Have you tried wetting drops?"

At this point, I'm pretty discouraged, having spent all the money to come up here, only to have them tell me they can't help. I guess sclerals aren't the answer for ultrasensitive eyes? If not - what is?

[Rebecca Petris]

Multiplier, I'm sorry to hear this.

Unfortunately there are some LASIK cases where there is residual nerve pain originating sub-surface... I've known a few where the source could actually be visualized with confocal microscopy. Also, I kind of wonder if in addition to surface dryness you might have tight eyelids?

For the discomfort from wind, dry air etc. have you tried moisture chambers?

[multiplier]

Unfortunately there are some LASIK cases where there is residual nerve pain originating sub-surface...

Yeah, I've been reading a bit. The deal with me is no that there's true 'pain' - it's just a constant 'raw' feeling of my eyes, the same as when you blow air on an open wound. It's not pain, it's another more abstract feeling of discomfort. I constantly have to narrow my eyes to make them feel 'shielded' from the light and environment.

Have people shown great improvement with glare/photosensitivity with sclerals? I've heard mixed things. Unfortunately, my eyes might be too ultra-sensitive at this point to wear lenses anyway.

I've known a few where the source could actually be visualized with confocal microscopy.

That was the last test they did in Boston. Dr. Rosenthal noted the abnormal look of the nerves, but did not suggest any procedure or treatment.

Also, I kind of wonder if in addition to surface dryness you might have tight eyelids?

Is that a result of LASIK?

For the discomfort from wind, dry air etc. have you tried moisture chambers?

No, but I'll look into it. I don't relish the thought of wearing glasses after undergoing a surgery that was supposed to make them unnecessary

[Raginator]

Nerves?

...there are some LASIK cases where there is residual nerve pain originating sub-surface... I've known a few where the source could actually be visualized with confocal microscopy.

How difficult would it be to "repair" these nerves?

It sounds like science fiction, but I have to ask.

Have any neurologists made observations or commentary about ablated corneal nerve endings? Confocal microscopy reveals nerve endings, but does it reveal how well or how poorly the nerve endings are functioning? What about a control group? Has anyone done confocal microscopy on post-Lasik patients who do not feel any dryness or discomfort? What would their tests reveal? Has anyone tried "repairing" corneal nerve endings... in humans or in laboratory animals?

Science fiction, but I have to ask.

My eyes don't feel "dry" during the day. They sometimes feel "irritated".

Thanks for listening.

[multiplier]

FWIW, this is the note I got from Dr. Rosenthal:

"The condition I believe that you suffer from is neuropathic corneal dysesthesia. Corneal laser scanning confocal microscopy showed the presence of abnormal nerve regeneration which is to be expected following LASIK. The scleral lens alone will not alleviate your symptoms. If your symptoms are significant I suggested that you consider our protocol involving sodium channel blockade."

I'd like to inquire further about methods of repairing the nerves, if such a thing is possible.

[alywankin]

post lasik abnormal nerve regeneration

just wondering......
would this "abnormal nerve regeneration" actually cause dry eye (either by aqueous deficiency or MGD) or is it more of phantom pain? (ya know - real pain but not actually caused by dry eyes)

[Raginator]

These corneal nerve endings: are we talking about damage to the dendrites or the axons? Or to the whole cells? I'm thinking back to my high school biology days (20 years ago). How many nerve "endings" are there? 10? 50? 100,000?

Are there any tissue engineers trying to create corneas in petri dishes? I figured they'd have some ideas.

::Sigh:: I'm in science fiction la-la land, huh?

[Raginator]

Sodium channel blockade????

I've never heard of this before.

What is it?

[sazy123]

multiplier

I had a similar experience with sclerals. They and any contact that you can get currently arent for inflamed sensitive eyes/eyelids.

In my case i have inflamed inner eyelids (conjunctivitis/ ocular rosacea) they are very sore if i touch the inner eyelids with a q-tip.

So i found sclerals to be a discomfort to my eyelids.

Have you tried autogulous (sp) Blood serum eyedrops? they are supposed to be beneficial for surface nerve repair etc, so ive read.

[ron s]

I found your post very interesting ...

Dear "Multiplier" -- i found your post very interesting -- I too have issues of dry eye with photosensitivity. I had lasik much more recently than you (Dec. 2007). When you talked about the sensations you have ("... the sensation is almost a mental one - I feel disoriented and distracted, and my eyes feel 'tight'. I had always associated all this with dry eye, but my Schirmer's test revealed only moderate dryness.") I felt as if the words had come out of my mouth. --- Like you, my doctor has said my eyes do not appear to be dry (esp. from the "dye" test), and your description of your eye feeling like an "raw wound" is how I have described my condition to people. I too had contact lens intolerance (but just in one eye) but if was only after 10 or so years of straight use, and only after I tried contacts again after a break from them.

I can completely relate about describing the problem to doctors and the how difficult it is b/c of the vagueness and abstractness. While I certainly cannot say that my problem is the exactly the same as yours i certainly have found your description the closest yet to the state of my eyes.

That being said, I hope I can learn from what you have tried thus far (even though you have not yet found success). Is there any general advice, tips you could give? Is there something in particular I should look for in a doctor?

[odydnas]

I havent had lasik, but I have been wondering lately whether or not dry eyes is my main problem...my eyes do feel like a raw wound, they are so sensitive.

As for what sodium channel blockade....I am going to venture a guess based solely on the name. Action potentials occur with the movement of sodium and potassium ions through their respective channels. Action potentials are necessary in order for neurons to transmit and receive signals from one another. Some anesthesia work by interfering with the excitation and conduction of actiona potentials by blocking their voltage gated sodium or potassium channels, so the nerves can't feel anything. So I am going to guess that a sodium channel blockade will is something like longterm anesthesia for the eyes, and therefore desensitizing them. I wonder if anyone here has done this and has success? I am very interested...

[carabiner]

For several reasons I find this post interesting. First of all I’m going to try a scleral for my right post-lasEk eye (done some 5 years ago) in May this year.
My pain experience is somewhat the same. Also I don’t really have dry eyes (and the blepharitis is reasonably under control).

The idea of a drug suppressing the pain via sodium channel blockade sounds promising, but isn’t very innovating probably – see the article below.
I’m on nortrilen right now, a drug related to amitryptiline, that also works via the mechanism of sodium channels (among other action-ways). A drug that certainly works to reduce my ‘mentol sensations’. The side-effects are not marginal nonetheless.

So the question remains: when will there be a sodium channel blocker that can be administered locally?? – When this is at all possible, and the working mechanism is not central -.





article:
Kalso E.
University of Helsinki, Institute of Clinical Medicine, Pain Clinic, Department of Anaesthesia and Intensive Care Medicine, Helsinki University Central Hospital, P.O. Box 340, FIN-00029 HUS, Finland. eija.kalso@helsinki.fi

Subtypes of tetrodotoxin resistant voltage-gated sodium channels are involved in the development of certain types of neuropathic pains. After nerve injury hyperexcitability and spontaneous firing develop at the site of injury and also in the dorsal root ganglion cell bodies. This hyperexcitability results at least partly from accumulation of sodium channels at the site of injury. The facts that these sodium channels seem to exist in peripheral nerves only and that they can be blocked at the resting state (use-dependent block) offer the possibility to develop drugs, which selectively block these damaged, overexcited nerves. At the moment no such drugs are available. However, some of the most potent drugs that are currently used to manage neuropathic pain e.g. amitriptyline and other tricyclic antidepressants, also block these channels in addition to having several other mechanisms of action. Also most anticonvulsants that are used to alleviate neuropathic pain are sodium channel blockers. Lidocaine, the prototype drug, has been shown to be effective in peripheral neuropathic pain. Its use is limited by the fact that it cannot be administered orally. An oral local anesthetic type sodium channel blocker, mexiletine is an antiarrhythmic agent that is effective in neuropathic pain. However, effective doses may be difficult to achieve because of adverse effects.

PMID: 16178759 [PubMed - indexed for MEDLINE

[buntbean]

corneal neuralgia

I have suffered for 5 years with severe dry eye and eye pain. The pain came on suddenly one day while shopping. I was fine one second and then in severe pain the next. Like ice pellets being shot into my eyes. My lower lashline felt like welding sparks or bacon grease was being splattered into them. I almost killed myself during those first 3 months. I was hospitalized and a neurologist suggested gabapentin 1200mg 3X/day. I also take tramadol 3X/day and cymbalta 60mg at bedtime. I use restasis, and thera tears (every 5-15 min), and celluvisc at bedtime AND during my afternoon "rest". My life isn't great. I miss out on a lot, my eyes are always dry and irritated but the pain I initially suffered is cut down enough now that I can function again. I did go to the Boston Foundation for Sight and I could not tolerate the lenses. The edges felt like they were trying to dig into my eyes (although the moisture was wonderful). They did a scan and told me my eyes were "hyper-sensitive" and that I have corneal neuralgia. They suggested a new therapy called the scrambler. I guess they place electrodes around your eyes and it's suppose to "scramble" the pain signals the nerves send. It's only for the neuralgia NOT for the dry eye. They said if it works I could cut down or stop the meds and possibly be able to use the sclera lenses. I have to admit it sounds good but when I was there (2/10) only 1 other woman had had the treatment so I want to wait awhile and see where this goes.

[mylittlem]

Do they suggest where this scrambler procedure might be done? Is it only being tried at the Boston Foundation at this point?

[ringo]

i wonder if you scramble any further the nerve signals that the corneal nerves send,i.e. if you desensitize the cornea in this way, whether you might end up with a completely disrupted nerve signalling process and that would lead to severe dry eye, as the tear glands need these signals from the corneal nerves in order to secrete tears.

It sounds like anaesthesizing the eye-- and that would definitely lead to a drier eye, which in turn would further compromise the nerves through inflammation and corneal surface damage.

I would think a neuroophthalmologist would have to be consulted.