My pentacam & Orbscan

Hi, I did femto lasik 1 month ago , but i still have to wear spec. my presription now is left -0.75 and astig 0.50, right -1.5 astig 0.5.

but after i wear spec, my best correct visual acuity is only 20/40...i don't know why.

i am seeing starburst and ghosting on right eye. is there any problem? is there a decentered ablation... please help..
Original Post
The reason I asked about your pre-LASIK prescription was because your ablation zones look small. The higher your pre-LASIK prescription, the smaller the ablation diameter must be to avoid an excessive removal of corneal tissue. This adds to the ghosting and spherical aberrations. Although your pupil sizes seem small, the anterior chamber measurements are deeper than average (Pentacam OD 4.15 mm / OS 4.32) which effectively makes the "effective" ablation smaller than what is measured on the topography scans. And yes, the right eye is de-centered enough to exacerbate the starbursts and ghosting you are noticing in the right eye. The topography is also showing a significant amount of irregular cylinder, particularly in the right eye.

What was the date of your LASIK?
Your ablation zones were small and that is a significant part of your post-LASIK issues. Wavefront is not the solution to small ablation zones. The solution to small ablation zones is larger ablation zones. At best, in your particular case, additional ablation may be used to extend the transition (blend) zone surrounding the actual optical ablation zone and this might relieve some of your visual aberrations. Again, IMO, wavefront alone is not the answer. Many LASIK machines are marketed as a "solution" of problems following LASIK but if you think about it, LASIK machines are also 100% of the CAUSE of problems following LASIK.
That would depend on the calculations. If your surgeon is simply attempting to enlarge the blend zone then I would think some thinning of the flap might help achieve that benefit. It might adjust a little of the de-centration aberrations and may overall reduce some spherical aberrations. Did you get a copy of your aberrometry studies?
Yes,here is the aberrometer and corneal wavefront.

I afraid that my flap not enough for fixing the decentered, my initial treatment is -10.50, so it should take alot tissue to recentered the ablation.

according to OCT scan my thinnest area have 410um tissue.

100um flap - 55 epithelium = 45um?
did we need to reserve certain amount of thickness? or we can ablate more than the flap thickness direct to the stroma?
The thinnest area according to the OCT is 410 microns. Is this counting the flap? Probably. So, your thinnest stromal reading is more like 310 microns. How stable will the flap be if you thin it to 45 microns? Will it be optically viable? These are questions not easily answered and there are no guarantees. My expertise lies in understanding visual issues associated with refractive surgery but I have no expertise to advise you regarding how thin they can make your existing flap.

Add Reply

Likes (0)