Night vision problems and double vision after lasek

[cici]

I had wavefront lasek about seven months ago, to corrent approximately -8D of short sight and 2.5 astigmatism in both eyes. I still have large starbursts around lights in low light levels, which is not good for night driving. These rapidly disappear when the light levels go up, and reappear when light levels go back down, so I feel it's likely to do with the size of my pupils being bigger than the optical zone.

I'm going back to see the surgeon next week, to find out what can be done about it. The orininal surgery was done using a B&L Zyoptix laser. If my problem IS pupil size/optical zone, is enhancement to correct it possible with this kind of laser? I've been reading about the Wavelight Allegtretto, would that be a better option? (Unfortunately I would have to go to a different clinic which would mean paying out all over again...)

I don't understand how this could happen as my dilated pupil size was supposed to have been measured before surgery. Do you know what the maximum optical zone is for Zyoptix?

Another problem I have is double vision in my right eye, like a faint (but distracting) ghost image to the right of the main one, and I get this even in good lighting. What could be causing this? I've read about "irregular astigmatism" - if it's that, could a Zyoptix enhancement fix it?

I never had these problems before surgery, my "best corrected" vision was always excellent.

Many thanks for any advice you can give.

[LasikExpert]

I'm sorry to hear of your troubles. The information you provide indicates that your difficulties are probably all related to simple refractive error, which means you probably have many options available to you.

You refractive error before LASEK was very high. It would be reasonable to expect some regression of effect. It seems likely that you have some residual refractive error. Even a small amount of myopia (nearsighted, shortsighted) vision can cause halo and starbursting problems. They would be worse in lower light as your enlarged pupils will be letting in more defocused light.

Do you have a pair of glasses that fully correct your refractive error and do they improve your starburst halo problem when used?

Your description of the ghosting is classic regular astigmatism: a single ghosted image off to the side that gets worse in lower light environments. Irregular astigmatism would provide multiple images or general blur.

From you use of the term shortsighted, I assume you are not in the US. The Bausch & Lomb Technolas 217z Zyopitx has a 6.0mm optical ablation zone when in wavefront-guided mode, with a transition zone up to 10mm. If you have read our article on Lasik Pupil Size, then you know the relative importance of optical ablation zone compared to pupil size for high myopes.

Do you have your current prescription available?

[cici]

Thanks very much for your reply. You're right, I'm from England. I don't have my exact current prescription at the moment (would need to visit the optician on Saturday to get it), but I think the figures are close to zero: 0D shortsight in both eyes and -.25D astigmatism in my left eye and -.5D astigmatism in my right (the one with ghosting). I don't have any glasses at the moment, because in theory I shouldn't need them, and my distance daylight vision is good (the ghosting, though still there, is not too distracting under these conditions).

What's strange is that the surgeon meant to give me about 1.5D undercorrection due to cornea thickness, but I've ended up with full correction for shortsightednes - I was even a little bit long-sighted for a while when my eyes were settling. Maybe my eyes have healed strangely?

The starbusts in each eye are not symetrical, they are skewed to the "outer" edge of vision, but look symetrical when I use both eyes together.

I hope it is just refractive error, but what worries me is that I have quite large eyes, in in dim light my pupils look enormous (though difficult for me to measure at home). I wonder if a 6mm zone is big enough. I checked the clinic website and they now have something called "Zyoptix Aspheric" which I believe is something new - does that have a bigger zone or is it the same?

Once again, thak you very much for your help.

[LasikExpert]

I don't have any glasses at the moment, because in theory I shouldn't need them...

I often say that nothing screws up a perfectly good theory faster than reality.

Your final result of plano with a small amount of astigmatism is within the normal result for laser assisted refractive surgery. Remember that normal human fluctuation in vision is about 0.25 diopters.

When you pick up your prescription, ask your doctor to demonstrate to you the direction of your astigmatism. I suspect that you can correlate the asymmetrical starbursts precisely to the astigmatism. Depending upon the conditions, they will be either in line with the astigmatism or 90 degrees.

It appears that for whatever reason, your corneas react more to the laser energy than the average cornea. This would account for the lack of an undercorrection. It is fortunate that the target was undercorrection so you did not end up being overcorrected into hyperopia (farsighted, longsighted) vision.

Zyoptix Aspheric is an updated nomogram that controls the way the laser removes tissue. I do not know if the new nomogram would have made any difference in your case or if the new nomogram would be of specific importance if you elect to have enhancement surgery. This is something that your doctor can discuss with much greater detail and knowledge.

What you describe sounds like simple refractive error. If your doctor can resolve these problems with the phoropter (the device you look through with all those lenses while the doctor asks “which is better one or two?”) then that would affirm that the problem is refractive error. Refractive error can be resolved with glasses, contacts, or possibly enhancement surgery.