LAL - First adjustment
Posted , 6 users are following.
I got my first adjustment for the RxSight Light Adjustable Lens three weeks after implantation.
- Refraction was +0.50 sphere, -1.00 cylinder before the light treatment. 20/25 or thereabouts, correctible to 20/20.
- I'd have been unhappy with a +0.50 D outcome if I had a non-adjustable lens. I hope my surgeon would have been more conservative and chosen a lower-power lens if he were using a non-adjustable lens, but I still feel like I may have dodged a bullet here.
- The LAL eye is to be my near-vision eye in a monovision arrangement. Target result for this first adjustment was -1.50 sphere, 0.00 cylinder. That is a total of 3.00 D adjustment, or 2.50 D if you only count half of the cylinder diopters. I remember reading that there's a limit of 2.00 D per treatment, and I also heard somewhere that each treatment can adjust either sphere or cylinder, but not both at the same time. According to the optometrist doing my light treatment, neither of those limitations exists.
- Dilation and blurred vision persisted all day but cleared overnight, and less than 24 hours after treatment, my near vision was greatly improved. I now read J1 easily in normal indoor light, and with good indoor lighting I read 3-point fonts, which is tiny print. Reading a book with relatively small print is comfortable, much like it was with my natural lens and pre-cataract LASIK monovision, but admittedly not quite so good as with my natural lens. About the only thing I need to get used to is holding the book ~16" away, rather than 5" from my face to get the clearest view.
- Intermediate vision with the LAL eye is good. My computer monitor is ~31" from my eyes, and I now see it well with both eyes.
- Distance vision is clearly poorer than it was before the adjustment. But I estimate the LAL eye is still 20/40, using my homemade eye chart. I think 20/40 is pretty darned good with J1+ near vision. Maybe this is attributable the LAL's reputed wide depth of field, or maybe my measurements are not quite right, but I feel like things are going well at this point.
- Next appointment is a week after adjustment #1. I've been planning to shoot for -2.00 D, but I'm quite happy with my near vision already, based on the initial target of -1.50 D and whatever actual result I got for myopia. My guess is that the first treatment did a good job on my astigmatism, and that contributes to the good results I'm seeing so far. If a second treatment can improve results further I will do it, but I may be ready to start the lock-in procedure this week.
1 like, 17 replies
RonAKA phil09
Edited
That all sounds very promising. You are doing well to have 20/40 distance with -1.50 D sphere. If you have sufficient reading vision, it may be best to use the next adjustment to fine tune to -1.50 D sphere, and 0.00 D cylinder, if you are not there already. I would check reading vision in dimmer light. That is where I have a bit of a challenge. My recollection from the video was that they do both cylinder and sphere at the same time.
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Thanks for the update. I'm sure it will be helpful for those considering LAL as an option, and also for those deciding on what to target for mini-monovision.
phil09 RonAKA
Posted
Thanks RonAKA. I am feeling like my present level of myopia is my ideal balance of good near vision and semi-adequate distance vision. If they tell me that the actual refraction is -1.25 D or -2.00 D, I don't think I would have any reason to want to tune in to -1.50 D. On the other hand, I should have a diopter or two of adjustment capacity remaining, so maybe it would be useful to try a slight adjustment and see if the result seems even better. Honestly, given a choice I don't know whether I would pick a quarter diopter more myopia or less myopia - it really feels like the right balance for me so far. I do have a few days to try it out and think it over, so perhaps something will change.
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I did not know how to check reading vision in dimmer light, so I tried a couple of things. Walked slowly into an unlit, windowless room, and gradually lost lines on the Jaeger chart. Exactly as I would expect. Then, at a pretty dim light level, I compared my naked LAL eye vs. my good eye with +1.50 reading glasses, and found the LAL eye sees a little better. Not very precise or scientific testing, but so far no indication of any problem with low light.
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As always, thanks for the input!
RonAKA phil09
Edited
To quantify your reading ability in dimmer light I would just use the Jaeger chart with different room light levels. Where I run into issues is dining out and reading the menus. Not very scientific but I find the more expensive the restaurant the dimmer the light. So, perhaps go out and celebrate with a good meal and see if you can read the menu. As a backup, take your phone with the flashlight!
trilemma RonAKA
Posted
There are also credit-card size thin fresnel lens. Inexpensive.
trilemma phil09
Edited
I suggest not being too overjoyed and thrilled. If you have measurable residual astigmatism, I would get another adjustment. Might as well.
There is some thought that astigmatism is not all bad, and adds some EDOF effect. I am a bit skeptical, but it may have merit. I would aim for no astigmatism. RonAKA??
RonAKA trilemma
Posted
Yes, I think no astigmatism is ideal, but some is certainly tolerable. In a perfect world I would take a bit more negative sphere over some cylinder to get the ideal reading vision.
phil09 trilemma
Posted
Thanks, trilemma. I will keep this in mind. I have read that LAL can correct astigmatism of 0.50 D or greater, but nothing smaller. Not sure that's true, but I will press my optometrist for any improvement available, either in primary, secondary or oblique astigmatism.
RonAKA phil09
Edited
I recall they claim adjustment of cylinder down to 0.25 D tolerance. I would ask if you are measuring more than 0.0 D cylinder.
trilemma phil09
Posted
They used to say 3/4D, which I thought was weird. I now think that may be the smallest astigmatism they can push to correct, but they can set 0.25D in on the light adjustment device.
AFAIK, they only adjust cyl and axis, and that is done based on the readings from the phoropter. I don't know what primary, secondary or oblique astigmatism are.
julie66167 phil09
Edited
You have no idea how much your post means to me. I am so glad that you can read well @ -1.50D as well as distance 20/40. I have been told repeatedly that -1.25D through -1.50D is where most people find their best near vision with the LAL. The 10 million dollar question: do you think you have any EDof? I hope you don't have any astigmatism left. I hope they nailed it.
Thank you phil09 for updating.
phil09 julie66167
Posted
Thanks julie66167 for the good wishes and I am glad if the post is helpful. I will trust the findings of the professionals at my next exam more than I trust my own impressions as a patient. But based on what I have read and what I am seeing, I do believe my recent LAL adjustment for myopia did extend depth of field to some extent. I may know more next week.
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My adjustment was done by a nice young optometrist; my very experienced, eminent opthalmologist did my surgery but does not perform the adjustments and was not present. The optometrist was surprisingly lacking in knowledge regarding any EDOF in the LAL, and even regarding the concept of depth of field. I found that unsettling, but she seems to have done a good job with the adjustment, however I did not gain any useful information on the EDOF thing. For what it's worth, she did tell me that there is only one type of adjustment for myopia - i.e., there is no option to adjust with or without EDOF.
julie66167 phil09
Edited
phil09, There must be so many algorithms for adjustments - each ophthalmologist must have created their own algorithms to obtain results the patient needs and desires.
Of course, I am guessing and I may not be using proper terminology. Do you think it is a "secret sauce" sort of thing? So I am thinking, your ophthalmologist carefully planned the LDD machine settings and the optometrist followed his instructions.
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The most important thing - that your astigmatism is corrected to the best possible refraction.
RonAKA julie66167
Edited
From what I understand the light adjustment is computerized and automatic, not manual. I suspect they program in the sphere, cylinder, and axis from the phoropter test, and the machine/computer does the rest, just like an eyeglass lens is made. Especially on the virgin IOL before adjustment they know the exact shape of the lens and just program in the correction.
phil09 RonAKA
Posted
I would think that's basically how it works - the manufacturer provides the light adjustment software and few, if any, ophthalmologists would have either the ability or the desire to program their own adjustments. At most, they might have some limited ability to configure options used in their practices. I don't think there's any secret sauce.
RonAKA phil09
Posted
I would think the biggest trick would be in getting consistent repeatable phoropter readings so you don't end up chasing your tail with adjustments. Consistently using eyedrops should help.
julie66167 RonAKA
Posted
RonAKA, I know you don't like YouTube videos. But maybe these are worth watching, Dr. Omar Krad tricks the LDD machine to extend depth of focus on the 1st light treatment. The LAL implants are for his father-in-law in the 1st one.
Google:
LDD treatments for the Light Adjustable Lens | My approach to Light Treatments for the LAL
and
LAL Depth of Focus after CATARACT Surgery | Reading as good as VIVITY lens?? Real Patient Feedback (beginning is tiresome - so watch from about 4:20)
RonAKA julie66167
Posted
I tried watching, but I am afraid I don't have the patience for his rambling anecdotal "evidence". To be convinced of this LAL depth of focus effect, I would need to see some FDA clinical studies done. It all seems hokey pokey to me...
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I want to see defocus curves for a statistically significant number of eyes to be convinced. And I guess the other annoying part is that I don't believe you really need any extension of depth of focus to make mini-monovision work. It works fine with standard monofocal lenses when you hit the right targets. I still believe that the advantage of the LAL is in the accuracy of hitting the refractive targets, not in the extension of depth of focus.