Recovery of corneal subbasal nerve density after PRK and LASIK.

[Scout]

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum

Am J Ophthalmol. 2005 Dec;140(6):1059-1064.

Recovery of corneal subbasal nerve density after PRK and LASIK.

Erie JC, McLaren JW, Hodge DO, Bourne WM.

Department of Ophthalmology, Mayo Clinic College of Medicine, Rochester, Minnesota.

PURPOSE: To measure and compare the return of corneal innervation up to 5 years after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). DESIGN: Prospective, nonrandomized clinical trial. METHODS: Eighteen eyes of 12 patients received PRK to correct a mean refractive error of -3.73 +/- 1.30 diopters, and 16 eyes of 11 patients received LASIK to correct a mean refractive error of -6.56 +/- 2.44 diopters. Corneas were examined by confocal microscopy before and at 1, 2, 3, and 5 years after the procedures. Subbasal nerve fiber bundles were measured to determine density (visible length of nerve/frame area) and expressed as micrometers per square millimeters. Differences were compared by Friedman's test and adjusted for multiple comparisons by the Student-Newman-Keuls procedure. RESULTS: After PRK, mean subbasal nerve density was reduced by 59% at 1 year (2764 +/- 1321 microm/mm(2) [+/-SD]) when compared with preoperative (6786 +/- 1948 microm/mm(2); P < .001). By 2 years, subbasal nerve density (6242 +/- 1763 microm/mm(2)) was not significantly different from density before PRK and remained unchanged to 5 years (5903 +/- 3086 microm/mm(2)). After LASIK, subbasal nerve density was reduced by 51%, 35%, and 34% at 1, 2, and 3 years, respectively (P < .001). By 5 years, subbasal nerves had returned to densities (4441 +/- 2819 microm/mm(2)) that were not significantly different from densities before LASIK (5589 +/- 2436 microm/mm(2)). CONCLUSION: Corneal subbasal nerve density does not recover to near preoperative densities until 5 years after LASIK, as compared with 2 years after PRK.

PMID: 16376651 [PubMed - in process]

[dnew85]

How Common Is It?

I know this information has been available for a while. I was wondering if anyone has experienced this continued healing and made it back to so-called pre-Lasik baseline dryness. I know that for us that are less than 5 years out (26 months for me) that gives us hope that this can still be a transient condition and we can return to some kind of normalcy. I love to read the success stories that are shared.

[desertcry]

interesting

I briefly read this article. I suppose it does give hope. I was operated a year ago with PRK and the article suggests that there may still be healing up to two years after PRK.

However, the author didn't seem to measure the degree of dry eyes in the subjects. This is strange because one of the motives they mention is it's (nerve density) link to dry eyes.

Desert Cry

[Hangus]

Any form of report or research that has an element of long term recovery is good news for those of us who have been here a while. I am now 30 months post Epi lasek on one eye and i have certainly improved and hopefully, if I am only half way through the recovery phase, I may yet reach full remission.

Barry

[Jeff]

I am 6 years post LASIK this May and I can honestly say that things are considerably (although not where I hope to remain) better than in the early days. I either have more good days or have become more tolerant of my circumstances. While I had both eyes done at the same time one gives me more trouble than the other on any given day. For what its worth the eye that is more troublesome is my left eye, they did my right eye first.

I am still hoping for improvement in some form.

Jeff

[Scout]

I know this information has been available for a while. I was wondering if anyone has experienced this continued healing and made it back to so-called pre-Lasik baseline dryness. I know that for us that are less than 5 years out (26 months for me) that gives us hope that this can still be a transient condition and we can return to some kind of normalcy. I love to read the success stories that are shared.

Hi dnew85,

I was looking for this study that I posted in 2006 because I wanted to link to it for Kyle (in another thread) when I was surprised to see it on the first page, with new posts.

In answer to your question, I would say that definitely my dry eyes (previously fairly dry prior to LASIK in 1999--I know, I know, bad candidate, but it was 1999 . . . .) returned to pre-LASIK dryness at about the 5 year mark.

I had previously thought my improvement was due to the allergy eye drop (Zaditor) that I was using quite liberally at the time. But when I stopped using Zaditor because it contains BAK, my dry eyes did not worsen.

I was really quite hopeful when I originally read this study and I posted it immediately. In the past, I had posted studies like this one on the lasermyeye forum, but DrG felt that I was unduly scaring the newbies. I do think that newly lasered dry eye folks may feel scared and helpless when they read a study that tells them that they could possibly suffer like they are currently suffering for five more years. They need more hope and the possibility of five more years is quite scary and depressing.

But many of us here on DEZ have been dealing with post-laser surgery dry eye for a long time and after a long time suffering dry eye and pain, those feelings of helplessness begin to seep in when we start to worry that this suffering could last forever. Reading that there may be an end in sight some time in the future, can bring back hope.

Some of us older members were told for years that it was not the laser that caused all of our symptoms (were we crazy? perfectionists? hypochondriacs?). This study showed an actual medical reason for some of us with longer-term complications. All of the previous studies (that I am aware of) only tested patients for up to a year. This one was one of the first long-term complications studies.

It did give me hope . . . and validation.

Scout

[Raginator]

Confocal Microscopy?

Confocal Microscopy was used to measure the nerve density? Did I read right?

Hey, can I go get a confocal microscopy? I wonder how my nerves are doing?

At Jules Stein, I received a bunch of tests. I don't remember the doctor talking about my nerve endings.

I'm 18 months post op and my dry eyes have improved quite a bit. Now, it's just a nuisance.

Has anyone here had a confocal microscopy? Or any other high-tech scan? Anything interesting?

[Raginator]

:::breathing deeply:::
Ain't nothin' like an old thread.

I wonder why 5 years is the magic number.

Why would nerve tissue take 5 years to regenerate, if I understand the claim of this study.

Not to complain, but why 5? Why not 2? Why not 20?