Comments on: Part 7: LASIK vs PRK/LASEK? Which laser procedure is best?

By: Dave Allamby

Dave Allamby — Tue, 17 Jan 2012 16:07:55 +0000

hi Steven, There is a very small, but not zero, risk of the flap being moved late on. Needs sharp direct trauma, which is possible in the contact martial arts you mentioned – finger tips/nails. It is quite reasonable to opt for PRK in this situation. It’s very hard to quantify the risk though. Regards, Dave

By: Steven Kapur

Steven Kapur — Tue, 17 Jan 2012 13:39:34 +0000

Hi Dave again,

Thank you for all your responses. I’ve been finding this blog very informative and useful.

One further question I have is how suitable is LASIK for combat sports such as Brazilian Jiu Jitsu and Muay Thai? I am currently not at a level were I am ready to spar but don’t want to rule it out in the future.

I have read various forums stating that people have had LASIK and still spar regularly as it would take quite a heavy blow to dislodge any flap. However they have to give the flap the maximum healing time of 3 months before resuming sparring. I am now in the situation were I am ready to book my surgery but still unsure due to the sports I participate in. I am also aware that the police now use LASIK as well.

Warm Regards,

Kunal

By: Dave Allamby

Dave Allamby — Sat, 14 Jan 2012 17:05:13 +0000

hi Irene
Tear break up time (TBUT) is normally 10 seconds or longer, so yours is too quick at 6 seconds to offer laser eye surgery. Leaving the contacts out for longer before having them tested again is necessary to get a truer measure of the the health of the corneal surface. Not sure about the Ultralase comment as it seems back to front. Having a double digit TBUT is a good thing, not the reverse, so you may have misunderstood that comment? TBUT needs to be longer to provide continuous moisture on the corneal surface between blinks. Laser eye surgery will reduce the tear film further and increase the risk of dryness problems.
You can continue with 2000mg as it will build up with time. This may or may not extend the TBUT to a point where it is safe for LASIK. So you have two issues that need addressing before laser eye surgery is safe for you: the stability of your prescription, and the quality of your tear film.
Best regards, David

By: Irene

Irene — Fri, 13 Jan 2012 18:17:52 +0000

Hi David,
Hope you don’t mind me getting involved in this thread, but I have been advised I have some dryness in my eyes but I think it’s mainly from contact lens wear. When I went to UL (my Contacts were out for24 hours) they advised my tear break up was 6 seconds (I’m not sure what that means?) and that they are only concerned about dryness when it gets into double digits for tear break up. Is this right?
I have been taking flaxseed oil 2 x 1000mg aday for about 6 weeks as advised on the label but I notice you advised Ness to take 4 x 1000mg a day. I have found my eyes have improved with the flaxseed oil but occasionaly still wake up with some dryness (I still wear contact lenses the majority of the time so I do appreciate that isn’t helping but I have switched to Acuvue Moist Dailies which have been great and my eyes are fine when my contacts are in, the dryness is when I don’t have contacts in).
So as I want to have laser eye surgery with yourselves when my eyesight has stabilised, should I take 2x 1000mg per day or 4x 1000mg a day?
Many thanks- I really appreciate all the advice you have given to help me with such an important decision.
Irene

By: Ness

Ness — Wed, 11 Jan 2012 22:12:42 +0000

Dear David,

Many thanks – I’ll start taking the flaxseed oil as you suggest and plan to travel to London in March.

Ness

By: Irene

Irene — Tue, 10 Jan 2012 16:09:03 +0000

By: Dave Allamby

Dave Allamby — Tue, 10 Jan 2012 09:58:09 +0000

hi Ness. My pleasure. I suggest that you start an oral supplement of flaxseed oil, 4000mg per day, taken with food. You can buy 1000mg capsules of flaxseed oil from e.g. Holland and Barrett. It takes 4-8 weeks to work in helping build up the tear film layer in your eyes. So if you do come to us for an opinion start the oil, and we could see you in early March. Keep any contact lens use to a minimum, and don’t wear them for 2 weeks before you come along. That we we can assess the health of your cornea and tears much better.
Best regards
Dave

By: Ness

Ness — Mon, 09 Jan 2012 20:54:19 +0000

Dear David,

Many thanks for this. What you say confirms my suspicions about what was said.

It looks like I will be making the five hour rail journey to Focus!

Ness

By: Dave Allamby

Dave Allamby — Mon, 09 Jan 2012 17:43:45 +0000

Ness, Yes you are right to be concerned when there is significant dryness pre-op. It is the one area where post-op problems can arise still. The best way to avoid such issues is not to operate where pre-existing dryness may lead to problems after. I suggest that you get another consultation where you can get a second opinion on the degree of dryness before going ahead with any form of surgery.

It is not unusual at my clinic to spend weeks/months in preparing the eyes so that the tear layer is optimised and there is the maximum available moisture before surgery. It is worth taking this time for a one-off elective procedure.

Best regards

David

By: Dave Allamby

Dave Allamby — Mon, 09 Jan 2012 13:21:09 +0000

Thanks Tom. Glad to help. Please call Barbara on 0207 307 8250 and she will be very happy to arrange. Best regards, Dave

By: Tom

Tom — Mon, 09 Jan 2012 13:02:24 +0000

Hi David,

Many thanks for your detailed responses. I will be in touch with you via Focus.

Regards

tom

By: Dave Allamby

Dave Allamby — Sun, 08 Jan 2012 12:12:16 +0000

hi Tom. We use a residual bed limit of 300 microns, which many clinics now use – thicker that the previous residual bed thickness of 250 microns – and with presumed increased corneal strength and safety post-op. You would need to ask which limit another clinic uses. I have entered your details into the WaveLight Allegretto Eye-Q laser, and fortunately your full prescription can be treated (leaving 301 and 304 microns respectively).
The tissue conservation from the WaveLight treatment profiles is very useful in cases such as yours. We can treat the full amount and still stay over 300 microns in the stromal bed, with a 6mm true optical zone. You would have to confirm with the other clinics as to the residual thickness and the treatment optical zone used. (Treating a smaller diameter reduces the ablation thickness but increase the risk of night vision problems).
Best regards, David

By: Dave Allamby

Dave Allamby — Sun, 08 Jan 2012 12:04:54 +0000

hi Irene, Your prescription falls in the moderate group (-3 to -6). For Z-LASIK, over 99% of eyes see 20/20 (or better) in this range, and all patients had binocular vision of 20/20 or better. Once you have a stable prescription we of course will be happy to see you. Better to be cautious and get the right result.
Best regards, David

By: Dave Allamby

Dave Allamby — Sun, 08 Jan 2012 12:00:18 +0000

Hi John, Each generation of laser improves on the one before. The iFS runs at 150KHz, so a faster repetition rate than the older 60KHz model. For performance, so the following review:
www.osnsupersite.com/view.aspx?rid=66406
Also Dr Perry Binder (from AMO) describes the improvement as:
“In terms of enhancements to the FS-150, Perry Binder, MD, medical director for Abbott Medical Optics…. “By running at 150 kHz, it allows the user to place the laser ablations closer together individually and row by row. This makes for easier flap lifts, smoother surfaces and overall faster procedures. So, for example, if you chose to use a spot/line separation of 8 µm and want a 9-mm diameter flap, you can complete that flap in 10 seconds, as opposed to about 21 seconds or so with the [previous] 60-kHz laser. Increased speed also decreases the risk of such things as suction loss and decent ration.”
This is a one-off procedure which is non-urgent and elective. You can always wait for the right technology if you feel there is a more advanced solution.
Regards, Dave

By: John S.

John S. — Sun, 08 Jan 2012 01:46:50 +0000

Dave,

Thank you for the input on resuming exercise in the gym.

I just wanted to get back to my question on the lasers again. I have decided on the surgeon who uses the Allegreto WaveLight Eye Q excimer laser. I feel very comfortable with his expertise and his clinic. However as mentioned in my first comment, he uses the 60hz Intralase femtosecond laser, not the new iFS or even the Zeimer that you recommend. Am I doing myself a disservice by using older technology on such an important part of the procedure? Do you feel using the 60hz Intralase would expose me to higher risks of flap complications, both during surgery and/or post surgery?

Much thanks for any additional input you could offer!