Optical Zone for 8.5mm Pupil

Question

I had lasik done in July 2010 and now I'm wearing mini scleral lenses to help correct the halos, starbursts and glare issues I'm having. My question is that my optical zone was done at 6.5mm my pupils measured out to be 8.5mm, transition zone 1.25mm, and ablation zone out to 9mm. What would be the possible cause of the issues I'm having? My thought is its the mismatched optical zone to my true pupil size. He told me an enhancement could make my vision better but I'm just really scared.

Christopher Coad, MD · Answer

Unfortunately there is no easy answer. Halos are much less frequent with newer, custom treatments, but can still occur. Some patients who have never had laser vision correction suffer from halos. Pupil size may be a factor. Consider an enhancement in only 1 eye to see if improvement occurs.

Sandy Feldman, MD · Answer

A common cause of night glare and haloes is a lower order aberration or prescription still left in the eye. An enhancement may help these symptoms if you have a residual prescription. One can try a PreVue lens with the VISX laser to determine whether than enhancement might help these issues. This may enable you to feel more comfortable going ahead with an enhancement. You also might want to consider treating one eye. Speak with your eyeMD about this possibility. Also, sometimes, individuals have higher order aberrations that are responsible for night issues. These can often be observed on wavefront testing of your eye.

Emil William Chynn, MD, FACS, MBA · Answer

There are many reasons why you might have night symptoms post-LASIK:

	
		they maybe should have increased your zones to cover your scotopic (night-time-sized) pupil
	
		all flap procedures like LASIK produce some night glare, as there is back-scatter across the interface between your flap and the bed of your cornea, as it's in a 2-piece sandwich configuration forever
	
		even if they retreat you with a wider zone, the blend zone may go past your LASIK flap, which would prevent this from doing anything useful, as your flap edge would be a sharp (non-blended) transition


	This is why I stopped doing LASIK years ago, even though I was the 1st LASIK surgeon in NYC to have it done myself (way back in 1999), because with LASEK, you can go way wider in your zones, and not be limited to the size of the flap, and not create inherrent night glare from the flap interface

	Before enhancing, you should do a diagnostic trial of Alphagan, which prevents your pupils from dilating. If this helps, going wider may help.  If it doesn't, it won't help. Better to know now, then just "wing it!"

	You should consider a LASEK CustomVue enhancement over your prior LASIK if the flap is too small a diameter to accomodate the wider zone. This is how I do all my enhancements now, and is safer than trying to dig up the old LASIK flap, or recutting an additional flap. You should also do a PreVue lens before your enhancement, if your surgeon in on the VISX platform, as then you again would avoid guessing that it might help before undergoing additional surgery. I did an article when the ASCRS journal interviewed 3 national experts on tools they suggested surgeons employ more when enhancing--my suggestion was that they employ the PreVue lens system more, as it does provide very useful and valuable information.

	Hope this helps!

	Emil William Chynn, MD, FACS, MBA

Optical Zone for 8.5mm Pupil

Answers (3)