Talk:Photorefractive keratectomy/Archive 1

Possible complications
Does anyone have any numbers on the probability of these? --Marco 17:24, 25 December 2005 (UTC)

Military acceptance
This article is out of date in that the Military DOES allow refractive surgery in aviation personnel. I just retired from the Navy and I was approved to treat all aviation personnel including pilots with PRK or other laser surface ablation. All refractive surgery is considered disqualifying for flight status, but waivers for PRK are routinely granted (I had over 100 approved and none disapproved) LASIK, as a less safe procedure than PRK, and RK, which can be unstable at altitude, normally are disqualifying and waivers aren't usually granted for LASIK or RK. Under some circumstances potential Aviation Officer Candidates may even have PRK at Navy expense to improve their vision to attempt to meet aviation vision standards to qualify to enter the program.

- recently retired Navy Ophthalmologist and flight surgeon

Concur:

Naval Academy Midshipmen provided the bodies for the PRK study for suitability ('98-'04, last I heard). 98.9% of us (sorry, can't verify the numbers) are now seeing 20/20 or better. I'm personally seeing 20/15.

Good stuff,

Thank you retired Navy Opthalmologist for your contribution to my improved eyesight.

--- OK, I'm an aviator in the Air Force and I'm leaving next week for PRK or LASIK surgery (I'll find out which surgery I'm a better candidate for when I get there). PRK has been approved for a while for all pilots and aircrew but LASIK was recently approved for all aircrew not associated with high altitude/high g's. Even more recently, LASIK has been approved for ALL pilots and aircrew, including fighter pilots in the Air Force. Wilford Hall Medical Center explains a little bit of the PRK/LASIK process on its website. [] But, let me stress that PRK AND LASIK are approved for all aviators in the Air Force.
 * Also Concur: I am currently in the Air Force, and know that PRK is definitely allowed and waiverable.  Currently LASIK is not, although I have heard (read: don't know for certain) that the FAA has approved LASIK for its pilots, so hopefully the Air Force will follow up on that soon.  (Note: I have horrible vision.  My contact lens prescription is for -6.50 diopters, meaning that even with surgery, I am only potentially qualified to be a navigator, not a pilot.  That, and the long healing time for PRK, are what kept me from doing it.  Plenty of my friends have gotten PRK, so I have seen plenty of what they have to deal with post-op.)--Nate Dawg 17:09, 20 June 2006 (UTC)

--SSgt Andrew Brown, USAF ---

It is waiverable for army flyers - I fixed the "citation needed" with a link to a document from the USAAMA (US Army Aerospace Medical Activity) 132.42.128.28 09:56, 13 September 2006 (UTC)

ASL
I've recently done a procedure called ASL (Advanced Surface Laser) which the doctor mentioned is an advancedment of PRK. I'm not exactly sure where this advancedment is. Can someone perhaps add the ASL section or add a new section together to compare the difference between PRK/LASEK/ASL/LASIK?

ASL works pretty much the same with PRK where the ephitelium is removed and let it grown back over the next few days. Hopefully an expert can add something to this issue. vhadiant 23:52, 15 February 2006 (UTC)

Images
Can we find some drawings of what is being done in the different forms of corrective eye surgery? RJFJR 16:18, 9 October 2005 (UTC)

no really international...
This last part of this article (Issues with patients requiring high visual acuity) is, in my opinion, too much euacentric.. is this the EUA wikipedia or the english wikipedia?

painful
i just got prk and wanted to add that before i got it i read this page and wasnt expecting as much pain as i am having i know no original research is allowed but post op it hurts pretty friggin bad [unknown anom editor]
 * I think that's an exception. I talked to dozens of people that had this procedure before I had it, and their experience was mostly like mine.  It hurt a little three days after it, but mostly it's just been itchy and dry.  The day of the procedure, I didn't have any pain or discomfort. mcornelius 20:52, 19 December 2006 (UTC)

Hmmm... apparently PRK rids one of the capability or the desire to use proper captialization and punctuation... [unknown anom editor]


 * I had PRK about four weeks ago. Pain came and went for the first couple of weeks; the days following the "permenant" clear contact removal worse than the days following the surgery. (I don't know how much of the difference was due to having a narcotic pain killer during the first such period and not the second and howe much was the sunnier weather during that second peroid compared to the first) The main thing is don't get in too bright an enviorment (office work enviorment) nor look at anything too bright (computer monitor) compared to surroundings during either of those periods. (Don't drive two hours towards the sun a couple hours after having the contacts removed.) And if an eye doesn't like being open even in the pitch blackness of a bathroom, it's probably very much overdue for having an optive eye drop. Jon 18:48, 23 August 2007 (UTC)

mitomycin-c and antimetabolite mitomycin to reduce haze citation
Found at http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=520812

BMC Ophthalmol. 2004; 4: 12. Published online 2004 September 14. doi: 10.1186/1471-2415-4-12. Copyright © 2004 Hashemi et al; licensee BioMed Central Ltd. Evaluation of the prophylactic use of mitomycin-C to inhibit haze formation after photorefractive keratectomy in high myopia: a prospective clinical study Hassan Hashemi,corresponding author1,2 Seied Mohammad Reza Taheri,2 Akbar Fotouhi,3 and Azita Kheiltash2 1Farabi Eye Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran 2Noor Vision Correction Center, Tehran, Iran 3Epidemiology and Biostatistics Department, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran corresponding authorCorresponding author. Hassan Hashemi: hhashemi@tums.ac.ir; Seied Mohammad Reza Taheri: mtaheri@noorvision.com; Akbar Fotouhi: afotouhi@tums.ac.ir; Azita Kheiltash: khiltash@razi.tums.ac.ir Received May 9, 2004; Accepted September 14, 2004.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. --Somewilliepete 18:51, 20 May 2007 (UTC)

LASEK
I was redirected here, searching for LASEK. Apparently there is no information about LASEK as of yet. From what I can gather, having read on the subject elsewere, LASEK is the newest of the three methods. It is supposed to be the one of the three, with the smallest risk of complications. Thorsten dk 23:38, 18 July 2007 (UTC)


 * Thats right. This article gives the idea that methods are the same. Lasek takes a microflap of cornea off to prevent hazing. —Preceding unsigned comment added by 69.148.163.194 (talk) 00:00, 5 May 2008 (UTC)

Some points.
PRK, photorefractive keratectomy was invented by Theo Seiler, M.D., Ph.D in Germany during the mid 80s. He performed the first trials in 1985 and treated the first functional eye with an excimer laser in 1987. (The article mostly covers the facts about the invention of LASEK by Camelin. )

PRK, LASEK, and Epi-LASIK and these procedures combined with the use of MMC (Mitomycin C) are called collectively Advanced Surface Ablation (ASA) techniques or Advanced Surface Laser....

The main difference between these techniques and LASIK is that only the epithelium is removed prior to laser irradiation of the underlying corneal stroma. The anterior (upper) part of the corneal stroma, exposed when the epithelium is removed (in an intact eye) is called "Bowman's layer".

These techniques require the removal of the corneal epithelium and the application of laser ablation on the exposed anterior surface of the corneal stroma. Corneal epithelium covers the whole cornea. Typically only the central portion of the epithelium is removed to create a circular opening of about 7-9 mm in diameter centered over the center of the pupil.

In PRK, after the ablation, new epithelium covers the treated surface in a time interval ranging from 3 and 5 days.

In LASEK, the epithelium is removed by chemical means, namely by exposing the portion of the epithelium to be removed to a mild (15-35%) solution of alcohol for several seconds (10-40 seconds). After this exposure, the epithelium can be peeled off as a continuous sheet. The surgeon, can carefully re-position this epithelial sheet over the treated zone of the cornea immediately after laser ablation. This (semi-vital epithelium) presumably reduces pain and protects the treated (and otherwise exposed portion of the cornea. There is a controversy wether this epithelial sheet actually has any positive effect on the healing process. The re-positioned epithelial sheet is replaced by new epithelium growing from the periphery (as in PRK) in 3-5 days after surgery.  Epi-Lasik is the same as LASEK but the epithelial sheet (often called "flap") is separated by mechanical means - a device called "epi-Keratome" similar to a LASIK microkeratome but designed not to cut a predetermined depth but to de-laminate the epithelium. All epi-keratomes function based on the fact that stroma is much harder to penetrate than epithelium.

MMC can be applied in all of the above cases as an attempt to reduce keratocyte activity after the treatment. Keratocytes are cells in the corneal stroma that are relatively inactive (although mobile) under normal conditions. Various bio-chemical signals after laser ablation may lead them to a state of rapid production of new collagen. This is an adverse reaction leading to regression of the corrected error (e.g. myopia) reduction of the geometrical uniformity of the cornea (uneven shape) and loss of transparency (increase of light scattering, often reported clinically as "haze".)

LASIK involves the creation of a flap prior to laser ablation. This flap has a thickness ranging from 80 to 200 microns (typically 100-120) and consists of the epithelium (typical thickness: 50 microns) and part of the anterior cornea. This flap, repositioned on the surface of the cornea after laser ablation promotes faster rehabilitation and moreover by avoiding prolonged exposure of the treated cornea (e.g. 3-5 days in PRK) it reduces the keratocyte - related adverse reaction mentioned above. LASIK is much less painfull. This factor (fast rehabilitation - less pain) was crucial for the wide acceptance of the LASIK technique, although several studies have reported that image quality is inferior to the quality that can be achieved with PRK (or the advanced surface ablations). —Preceding unsigned comment added by Harilatron (talk • contribs) 13:59, 22 September 2007 (UTC)

Insurance coverage

As these operations are considered optional, mainly are not covered by insurance co.s neither for the cost or for taking some weeks off your work, pls make sure to contact your insurance co. for detailed coverage. —Preceding unsigned comment added by 70.68.130.40 (talk) 19:11, 19 July 2008 (UTC)