I've been to 2 consultations in the last week to see if I'm a candidate, and so far I'm a candidate for PRK because my corneas are 470 and 475. I'm o.k. with that part. I can also accept the possibility of maybe not getting 20/20 or better like you hear about so much. What I am concerned about is my pupil size. The first place I went to didn't even measure my pupils,and whwn asked why, they said my optometrist would do that before surgery, when he does the pre-op exam, before he dialates my eyes. The second place I went to the technician did a pupil measurement with one of those pupil gauges where they match up the dot with your eye. There was a lamp on. Anyway, she said I had 7mm pupils. When I met the doctor about 10 minutes later he said I was closer to 7 1/2 mm. First of all, I've read this is not an accurate way to measure the pupil. Anyway, he recommended custom PRK with the visx laser, saying with wavefront it can treat up to 8.2mm. I read that the prescription portion is 5.0mm x 6.5mm with a blend zone up to 8.2. Now, common sense tells me that would put me at high risk for halos and glare etc., if my pupils are 7 1/2 mm. Please correct me if i'm wrong. Won't this "blend zone" let some light in? Now, the ladarvision laser "prescription" portion is 8mm x 8mm. So, i'm obviously a lot safer with the ladarvision right? The doctor with the visx said I would do fantastic with his laser. I don't trust that. My left eye....Sph -3.25 Cyl -2.25 Ax 020. My right eye...Sph -3.50 Cyl -0.75 Ax 150. These numbers are off my contact lens prescription, but should give you an idea where my eyes are that. Also, what kind of "cushion" should a person have as far as optical ablation zone/pupil size relation? When are the measurements too close? My eye doctor feels if there isn't a good 1mm difference, maybe I shouldn't do it. Would any of you call me an "ideal" candidate, based on info i gave here, or less than ideal? Any doctors that read this, your opinion greatly appreciated. Thank you.

Jim,

Your research, suspicions, logic, and conclusions are right on target. With a 6.0mm optical ablation zone you would have a gradually undercorrected blend zone, and a significant one at that. Although the method for measuring is not as accurate as with an infrared pupilometer, the dot method would indicate that your pupils are at least 7.5mm. In case you have not already read it, we have a detailed article about pupil size at http://www.usaeyes.org/faq/subjects/pupil_size.htm

The fact that your astigmatism is more than half of your myopia (nearsightedness) indicates that full correction of that astigmatism will be a bit more difficult. Residual astigmatism may cause doubled ghosting vision, especially with larger pupils. It is possible for the full correction to be made, but the pupil size gets in the way again.

You are not an ideal candidate, however your relatively low myopia is an advantage and your understanding of your circumstances will probably direct you to a proper conclusion about refractive surgery.

Glenn Hagele
Council for Refractive Surgery Quality Assurance
http://www.USAeyes.org
http://www.ComplicatedEyes.org

I am not a doctor.

>Jim,

>Your research, suspicions, logic, and conclusions are
>right on target. With a
>6.0mm optical ablation zone you would
>have a gradually undercorrected blend zone,
>and a significant one at that.
> Although the method for measuring
>is not as accurate as with
>an infrared pupilometer, the dot method
>would indicate that your pupils are
>at least 7.5mm. In case
>you have not already read it,
>we have a detailed article about
>pupil size at http://www.usaeyes.org/faq/subjects/pupil_size.htm

>The fact that your astigmatism is more
>than half of your myopia (nearsightedness)
>indicates that full correction of that
>astigmatism will be a bit more
>difficult. Residual astigmatism may cause
>doubled ghosting vision, especially with larger
>pupils. It is possible for
>the full correction to be made,
>but the pupil size gets in
>the way again.

>You are not an ideal candidate, however
>your relatively low myopia is an
>advantage and your understanding of your
>circumstances will probably direct you to
>a proper conclusion about refractive surgery.
>

>Glenn HageleCouncil for Refractive Surgery Quality Assurancehttp://www.USAeyes.orghttp://www.ComplicatedEyes.org
>

>I am not a doctor.
O.k. how about with the ladarvision laser, which has a optical ablation zone of 8mm x 8mm? Am I still at risk of "ghosting" or other problems? I thank you for your original response, by the way. I feel like the second doctor I went to(laservue) was not truthful about my outcome. And, I would think that they would suggest getting an accurate pupil measurement after their stupid pupil ruler indicated a fairly large pupil. I'm not taking any chances with my eyesight. I've worn contacts for over 20 years and I don't hate them, i would just love to not wear them, but I'm not willing to take more than a very small amount of risk.

The key is for the optical ablation zone (full correction) to be equal to or larger than the size of your naturally dilated pupil. That is the safest route, no matter what the laser.

It is important to note that recent studies have shown that there is no direct correlation between pupil size and night vision problems. Some people with pupils larger than the optical ablation zone have problems, some do not. Although pupil size alone is a poor predictor of night vision problems, the safest route continues to be an optical ablation zone equal to or larger than the naturally dilated pupil.

Glenn Hagele
Council for Refractive Surgery Quality Assurance
http://www.USAeyes.org
http://www.ComplicatedEyes.org

I am not a doctor.

Thank you for taking the time to respond Glenn. It means a lot to me. This site is great. I took this whole laser surgery thing serious, but not as serious as I do now, having done quite a bit of research. I want to do this, but the risk of complication has to be extremely low. I am going to get an accurate pupil measurment next week. If my measurement turns out less than the ladarvision's 8 x 8mm ablation zone, do you see any other potential problems, based on the info I posted in my original post? You said something about my astigmatism being half of my myopia, and that might be hard to correct. I might add that they(pacific laser eye center)said they can use wavefront on my right eye, but the fda hasn't let them expand the astigmatism parameters beyond 1.50 with the ladarvision, so they could only use traditional on that eye, leaving more of a chance for possibly needing an enhancement. He said they expect the FDA to let them expand the parameters in the next few months, which would allow them to do wavefront on an eye such as my left. Also said they won't know if wavefront is more beneficial on my left eye until they do the mapping that is done a few days before surgery. If I have a lot of higher order aberrations, then it might be beneficial to wait for the wavefront. If not, then traditional might be just fine. Is all this sounding right to you? Again, I appreciate your opinion. You said before I'm not an ideal candidate. How risky do you think it is for me? Thanks

You have just about exhausted the informed responses I can provide until you are re-evaluated. After the doctor gives you all the details, visit us here again.

>You have just about exhausted the informed
>responses I can provide until you
>are re-evaluated. After the doctor
>gives you all the details, visit
>us here again.

O.k. Thanks. Sorry If I'm being a pest, I just want to be careful, I only have one set of eyes. I'll come back after I get a real pupil measurement.

You are not a pest at all. I have a lot of respect for people who look before they leap.

Glenn Hagele
Council for Refractive Surgery Quality Assurance
http://www.USAeyes.org
http://www.ComplicatedEyes.org

I am not a doctor.

Thanks! A few weeks ago when I knew basically nothing about this laser surgery other than a few people I know have had good results, I took it a lot more lightly than I do now. After going to surgicaleyes.com and lasikdisasters.com (almost said "forget it" after that) I am taking this very serious. There is a pretty good chance I may not go through with it, but it will depend on my accurate pupil measurement. The thing about astigmatism in relation to my myopia has me concerned too. I'm probably scheduling the surgery tomorrow,but it will be a month away, so I have time to look into all the issues at hand. Thank you again for your help. Any doctors that read all my posts, your input would be greatly appreciated as well.

>Thanks! A few weeks ago when I
>knew basically nothing about this laser
>surgery other than a few people
>I know have had good results,
>I took it a lot more
>lightly than I do now. After
>going to surgicaleyes.com and lasikdisasters.com (almost
>said "forget it" after that) I
>am taking this very serious. There
>is a pretty good chance I
>may not go through with it,
>but it will depend on my
>accurate pupil measurement. The thing about
>astigmatism in relation to my myopia
>has me concerned too. I'm probably
>scheduling the surgery tomorrow,but it will
>be a month away, so I
>have time to look into all
>the issues at hand. Thank you
>again for your help. Any doctors
>that read all my posts, your
>input would be greatly appreciated as
>well.

Dear Jim: Congratulations on your caution and willingness to take the time to understand. May I suggest you read the articles by The Lone Dog on pupil size at http://www.lasermyeye.org/columns/archives.html where particularly in the third article there is a wealth of practical information about the proper and safe way to measure pupils so as to ensure that the true nighttime size is elicited. Personally I have observed this to be a relatively (and unnecessarily) frequent pitfall in the pre-operative process.

Kind regards

Rebecca Petris
www.lasermyeye.org

Thanks for the additional info on pupil size, it confirms the countless other things I've read. The place I'm considering going to didn't even measure my pupils on the first visit, because they say my optometrist does it at my pre-op exam before he dialates my eyes. They also gave me some info from the American Academy of Opthamology about recent studies that show that night vision problems are not caused by pupil size, but even in that article someone said "don't put the pupilometers away yet". I did do a consultation at Laservue in Santa Rosa where they use the Visx laser with the "blend" zone out to 8.2mm, and they assured me I'd be fine, right after tellingme I have at least 7mm pupil, closer to 7.5 (according to the doctor). This was determined by one of those gauges where they match up the dots on the card to your eye with the light turned down low. That is not accurate to me. If I get the PRK done at the place I'm considering, they use the Ladarvision laser, which has an ablation zone of 8mm. Anyway thank you, I don't know what to do. I sure wish some doctors would give me some input since this is called ask lasik doctors.com.

Rebecca and Glenn are doing a great job.
There is no question that pupil size is important in refractive surgery. There are major flaws in the studies that have come out recently.

1. The Schallhorn study had an insufficient number of large pupil patients to make any conclusions on the issue of pupil size and night time vision problems.

2. The Pop and Schallhorn studies have a major flaw in their study. They looked to see whether patients with pupils that are larger than the manufacturer's optical zone had night time vision problems. The problem is that they did not control for the level of myopia. This is critical, because according to Dr. Jack Holladay's article in JCRS 2002 "Topographic changes in corneal asphericity
and effective optical zone after laser
in situ keratomileusis" - the final functional optical zone for a patient shrinks with increased levels of myopia. So for every diopter of myopia of treatment, the final optical zone will be smaller than the Manufacturer's optical zone.
I am sure this is confusing - but the key is that the articles have not shown that pupil size is unimportant - and therefore pupil measurements are important.

I hope this helps

Best regards

Bill Trattler, MD
Miami, FL

Thanks for your input Bill. Much appreciated.The attachment the technician sent me was the Pop and Payette study, must be the same one or very similar. You being a doctor, you can find the flaws, where as I have to decide whether or not to believe it. So, put what you said in more layman's terms for me with my numbers, if you would please. My contact lens prescription is..Left Sph-3.25 Cyl-2.25 Ax 020. Right Sph-3.50 Cyl-0.75 Ax 150. The place I went to for my second consultation measured my pupils with that "dot" gauge in what I would say was light that isn't as dark as the inside of my car at night.PLus she turned the light down, measured immediately, said I was a 7mm, and then the doctor said I was at least that, probably closer to 7 1/2mm. Anyway, I wouldn't go there because they have the visx, and I don't believe I would have a good chance of not having night vision problems with that laser's ablation zone.Anyway, the place I may go to on Feb. 12 uses the ladarvision, and the technician is having me go to the doctor that will do the surgery for a pupil measurement using a pupilometer(don't know what kind, think he said the infra red kind), and he was saying that any measurement under 8mm will mean that I will be fine. Would you agree? Some people say that should have a 1mm difference between the ablation zone and pupil size(including my optometrist). I'm just real skeptical at this point since it's obvious my pupils are a good 7mm. I appreciate your input on this very much. Thanks in advance.

It's me Jim(again).I'm getting an accurate pupil measurement Feb. 2, and that will pretty much determine whether or not to go through with the PRK. Now i'm a little confused about the treatment zone with the ladarvision laser. I've read that the optical ablation zone is 8mm x 8mm,which would be ideal for me as it looks like my pupils are at least 7mm. But the tech told me yesterday that only applies to wave, which they cannot do on my left eye yet, because my astigmatism in my left eye is outside the parameters the fda has approved for wavefront with that laser. But they can do wavefront on my right eye. But, in another breath, he says they can pretty much make the ablation zone any size they want with that laser. I'm confused. Anyone have any input on this. Depending on my pupil measurement, I may wait to do the procedure until the fda expands the astigmatism parameters for wavefront on this laser, because the tech says they always feel that wave is better. I've read that sometimes the results aren't better with wave, depending on the individual, so any input on this issue also appreciated. And Bill, if you read this, could you give me your input on my previous post(right before this one) Thanks in advance to anyone who reponds.

To be safe - it is nice to have an ablation zone that is larger than the patient's pupil size - and that will happen for you if you go with the Autonomous.

The doctor can adjust the zone size - so the techician is correct that the doctor can make it bigger or smaller (we are talking non wavefront). I do not know the details with wavefront.

Is wavefront better than regular? Early studies by Dr. McDonald found that PRK wavefront was better than regular PRK and better than wavefront LASIK. So perhaps this still holds true. I can tell you that most patients are very happy with their vision with PRK, since there is less chance of aberrations being created from the flap.

What should you do? You are doing the appropriate thing by gathering lots of information. You have to make an informed decision as to what would work best for you.

I hope this helps

Bill Trattler, MD
Miami, FL

Glenn or Bill(or anybody else), if you read this, your opinions greatly appreciated.....
I've only posted a few times here regarding my upcoming PRK, which I don't think I will go through with, at least right now. I went to the surgeon's office today for a pupil measurement with a pupilometer, and he said my right eye was 7.4mm and my left eye was 9.2mm. This sounds weird to me.It sure didn't look like it was second nature for him to be using the pupilometer, but what do I know. All the lights were on in the room, and then he dimmed them, and immediately checked my eyes. That might explain why the pupil he checked second was bigger. Anyway, it confirms I have big pupils. He said he doesn't use a pupilometer unless the patient makes him(like me). His reason is he doesn't believe big pupils are the cause of night vision problems. He believes that spherical aberrations are more to blame. I might as well list my other stats. Refraction from wavefront left eye...Sph-3.53 Cyl-2.38 Ax 15 Spherical aberration 0.02 Coma 0.80 Refraction from wavefront right eye...Sph-4.04 Cyl-0.69 Ax 161 Spherical aberration 0.08 Coma 0.71
He recommended wavefront ladarvision which he says doesn't induce spherical aberrations, and that would be my best chance of keeping my risk of night vision problems low.This would have a 6.5 ablation with a blend to 9mm. I said what about my pupils being bigger than the ablation zone and the blend zone being less than 100% corrected and causing problems. He says that doesn't cause problems.The traditional ladarvision can have a treatment zone of 8mm with a blend out to 10mm, but they would have to take more tissue, or something like that. Also, he says that traditional ladarvision can increase the spherical aberrations, and since mine are already high, I'd be asking for trouble.He did say I have a little more risk of having night vision problems, but I'd have to ask myself if that risk is worth taking to have good daytime vision,that sometimes it's a trade off. To sum it up, my research tells me I'd have more than a small chance of night vision problems under these circumstances. What do any of you people think? Any and all opinions from anybody greatly appreciated. I'm canceling my Feb. 12 surgery tomorrow because, even If I do go through with this, it will be at least a few months, as wavefront ladarvision isn't yet approved for the astigmatism in my left eye. Thanks in advance for any opinions. I think there are too many red flags for me, who agrees? Or doesn't?

Jim,

It's been a few months now and I wonder if you have decided to go with the surgery and with what technology.

In short, I was overjoy to see your postings because I am going through the EXACT same experience as you did - I only spoke with a few friends who had good results a month ago, got the info of the laser facilities, went to my first consultation without knowing anything about laser vision correction. I am an auditor so natually I began suspicious when there was too much sales pitch going on. I raised my red flag and stepped back and started to do more research and here I am. I have been to 4 doctors since my first consultation. I received different, sometimes opposite, opinions on which LASIK I should go with.

I also have large pupil = 7mm