How long to get used to new IOL?

I was fully corrected to distance with contact lens. But i was having big difference in eyes after first rye surgery 10 days ago, and that eye now went from -11.5 to -1.75. Because of the nauseated feeling after surgery, I asked my optometrost to gove me a -0.5 lower power contact lens. i don't think it has helped!

I have never heard of doing a refraction test after dilation. I believe it is done after the refraction test is done.

Hi Ron,

Yes i will meet with my optometrist in mid February and hace him checked my refraction and lens placement.

For the surgeon, i will ask him tomorrow if i can get an appointment with him before my second surgery. I am not sure if he will or will not change the calculation or target. I think as long as i dont end up hyperopic and i can balance two eyes, i will be happy to wear glasses. He is already thinking I am a high maintenaince patient!

I did have both measurements before my surgery abd i compared them. One was done in November 4th 2023 and the current surgeon's measurements was done on Jan 2nd 2024. AL for both eyes are close.

R eye L eye

AL 27.25 27.31

AL(Nov) 27.23 27.27

LT 4.08 3.82

LY (Nov) 4.07 4.10

I also checked the card. It is the correct Envista 9.0D.

Hi Ron,

My previous response is still under review... so in short:

I planned to talk to optometrist about my refraction and see if i can manage -1.25 between eyes.

for my surgeon, I am not sure he will or will not recalculate the IOL. But i plan to discuss with him about a target he thinks can balance my eyes.

I did compare my two measurements and they are pretty close. One was done in Nov 2023 and the other in Jan 2024. AL for R eye are 27.23, 27.25. L eye are 27.27, 27.31.

also check my card and it is right 9.0D Envista

Good that the IOL power was what was planned.

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The strange thing with your AL measurements is that there is not that much difference between your eyes. Assuming your first number was from the IOL Master and the second for each eye was the Lenstar, I see only a 0.04 mm difference with the IOL Master and 0.06 mm with the Lenstar. I found one reference that suggests sensitivity to AL is 4 D per 1 mm. That would suggest a difference between the eyes of 0.16 D for the IOL Master and 0.25 D for the Lenstar. This is not a lot given that you seem to have a full 1 D difference between the eyes. This may suggest that the K1 and K2 values are having more of an effect than the AL.

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Do you have the complete set of data from the IOL Master measurements? If so, I would be willing to redo the IOL calculations with them instead of the Lenstar values to see if that reveals anything.

I posted a link to a video on exercises to adapt to monovision, but for reasons I don't understand it was deleted by the moderator. In any case try googling this to find it:

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YouTube How to get the best from Monovision wellingtoneyeclinic

Suggest you also check the difference between the K1 and K2 values from each of the instruments. They may be having more of an effect than the AL measurements.

Ron,

Not sure what are all the parameters you need but here are some from the IOL Master:

OD OS

AL 27.23 27.27

LT 4.07 4.10

WTW 11.9 12.0

K1 44.75@0 45.10@53

K2 44.91@90 45.39@143

Ron,

Today at my second post op, my refraction is -1.25. Surgeon said my eye wont be stabilized for another 2-3 weeks so we will meet in mid March to discuss second eye target.

Since we targeted -0.5 to -1.0 and picked 9.0D with predicted outcome of -0.6, he said we almost nailed it.

Well -1.25 D is better than -1.75 D, from a degree of miss point of view. Is that a spherical equivalent or just sphere? But, even at -1.25 SE that is still not almost nailing it compared to a target of -0.6 D, but perhaps it will get better from a miss point of view as the eye fully heals. The down side is that getting better from a miss point of view may be moving more to the no man's land area for mini-monovision which is not myopic enough for good near vision, and too myopic for good distance vision.

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I see two posts waiting to be moderated. What was in them that caused them to get dumped into moderation?

Sam the two values missing are ACD and CCT. Do you have those from the IOLMaster?

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I guesstimated these values and did a quick run of the numbers. On your left eye the Barrett formula made the best prediction of results with the +9 D power lens predicted at 0.99 D. If your eye stays at -1.25 D or perhaps even reduces a little more that is well within the normal accuracy of prediction.

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And if these guesstimates are reasonable it would appear the IOLMaster readings are giving better results. The Barrett formula with a +9 D power predicted an outcome of -0.76 D with the Lenstar numbers.

-1.25 is the spherical and -0.5 is cylinder. So SE is -1.25+0.25= -1.0?

I don't have the CCT from the sheet. ACD OD is 3.53 OS is 3.50

-1.25 sphere and -0.5 D cylinder add up to -1.50 D spherical equivalent. Check that the cylinder number is negative. Optometrists report it that way, while ophthalmologists usually report it as a positive value and then it requires conversion.

I will update the calculations with the IOLMaster ACD values and see if it makes a difference.

I updated the calculations with all the IOLMaster data you have. There was no change with the ACD number added. The Barrett Universal II formula using the IOLMaster data gave the most accurate prediction of what your outcome has been in your left eye. It predicts -1.0 D, and your outcome to date is -1.50 D. So it seems to underestimate actual myopia by 0.5 D. So one method for your left eye would be to target 0.0 D, and expect to get -0.50 D for an outcome. Another method is to adjust the A-Constant to get an accurate prediction of your outcome for the left eye, and then use that A-Constant for your right eye. I did that and the prediction using a +8.0 D lens is -0.37 D, and -1.05 D for a +9.0 D lens. Not sure what you want to do with the second eye. -1.0 D would be a better match for your left eye, but both eyes would be in no man's land where neither will give good near vision or good distance vision without glasses. Having your right eye at -0.37 D would give you pretty good vision for distance without glasses, and whatever you have now with the left eye for near. I will post the predictions for both eyes using the adjusted A-Constant, but it will get moderated, so I will put it in the next post.

Here is the Barrett Universal II predictions with the A-Constant adjusted to give you what you have now for an outcome in your left eye; -1.50 D. The predictions for the right eye are shown using this updated A-Constant. The standard A-Constant is 119.2, and I had to adjust it down to 117.3 to get your actual outcome (so far) in the left eye. When you get an actual final refraction at 5-6 weeks I can check it again for you. But for now your choices for the right eye would seem to be:

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+9.0 D to give -1.05 D SE

+8.0 D to give -0.37 D SE

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+9.0 would balance the eyes better and you will eyeglasses for sure

+8.0 D would give you good distance vision without glasses with about a 1.0 D differential between the two eyes.

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Statistically, what is the 95% Confidence Interval for the predicted 1.0 D differential between the two eyes with a +8.0 IOL in the second eye with +9.0 in the first. What is the range of outcomes in that interval? Some people may have problems when others don't even at a 1.0 or under differential.

There is no 95% confidence in hitting IOL targets, unless you use the LAL.

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There is something unique about Sam's eye and/or the surgeon. The outcome in the first eye (so far) is 0.9 D off the mark to the more myopic side. The surgeon needs to identify what went wrong with the surgery and correct that, or adjust the target to compensate for the expected off mark outcome if he is going to do everything the same. Good surgeons track their outcomes with each type of lens and adjust their predictions either with a surgeon factor, or a surgeon specific A-Constant. Not sure if this surgeon is in that category. He thinks he "nailed it" with a miss of 0.9 D... The unfortunate reality is that many surgeons are not that concerned about hitting the target, especially if they slot you into a category of needing eyeglasses. They just assume any error will be taken care of by the eyeglasses. And, that is true, if there is no value assigned to being eyeglasses free.

"The unfortunate reality is that many surgeons are not that concerned about hitting the target, especially if they slot you into a category of needing eyeglasses. They just assume any error will be taken care of by the eyeglasses. And, that is true, if there is no value assigned to being eyeglasses free."

Yes, that is indeed the unfortunate reality.

the sherical and cylinder numbers were from the balloon machibe and both are negative values.

Best to wait for a full phoropter refraction results 5-6 weeks post surgery before making any decisions. When you get them I can update the predictions if the numbers change.

Most surgeons only concerned with successful removal of cataract. If target hit, then that's a bonus! My surgeon is definitely thinking i can use glasses to correct distance vision. I will meet with him two weeks before my second surgery to discuss the second eye. Hope he will be more concerned with a more accurate outcome.

So you got an approximate refraction and the Rx is equivalent to about -1.5D.

Visual quality is not just about hitting a certain refractive target. How do you like your vision in the operated eye? Do you have good intermediate to near vision? The way you described it before it sounded like you had near vision but not intermediate. Do you require reading glasses to read? Can you use the computer without glasses?

What about visual quality? Do you have good vision in the evenings? Good contrast? Are you experiencing any dysphotopsias?

How is it going with the vision imbalance? Ate you adjusting or are you still very nauseous?

Your experience would be super helpful to me as I am planning my first surgery in mid-March. I plan to get he HumanOptics Aspira-axA XL in spherical power +4D for a refractive target of -1D residual myopia and 0.3D corneal astigmatism. I plan to wait six weeks between surgeries, am hoping I can tolerate the vision imbalance!

Vision imbalance due to image size differences is managed best with contacts. I recall you are comfortable using contacts. Should work.

yes, thank you! I think I may opt to wear a patch over the unoperated eye though because my vision is so terrible with the cataracts that I don't think a contact lens will do much.

How long do you recommend waiting between surgeries? The new surgeon I found advised waiting six weeks.

5-6 weeks if the minimum for eye recovery and being confident where the eye has landed. Anytime after that and after you have finalized your decision for the second eye should be fine.

hi Ka,

for me, every morning is resetting my vision as i put my contact in. it took a few minutes to adjust my overall vision daily after inserting contact lens. i am getting more used to the differences but they are still frustrating. it seemed like my second cataract is exaggerated from the first surgery.

i didnt have any dysphotosia until last week. i started seeing light streaks coming off of my ceiling lights and also cars with intensed headlights. The light streaks were shorted last week but since yesterday, they become longer and sharper. Anyone knows why? Do i have to live with them? Help!

i dont need reader if i hold out phone to sbout 16-17". i can see computer well without glasses. on a sunny day, my distance vision is not perfect but seem like i can drive without glasses. But under flouresceht light, the eye seems more blur. is that nornal? i might need glasses to drive at night.

Hi Ron,

i feel reflections off the sides of my eye abd bottom of eye. Is this normal? will they go away? i am a month in.

i also just reply to Ka about the light streaks. a bit freaking out about these!

I have a very minor amount of glare (starburst effect) but only when I am outside at night. I see it from LED headlights and tail lights, and some traffic lights. I don't see them on indoor lights.

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I do see flashes of light in an arc shape in my peripheral vision but only under very special circumstances. It has to be very dark, and the light source has to be off to the side. I see them in both eyes. I see them so infrequently it is not an issue for me.

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Hard to say if the effects will decrease over time. 5-6 weeks are needed for full recovery of the eye. The edge effect thing, I think is more a matter of bad luck combined with a larger pupil and where the lens actually ends up settling in the eye.

did you notice the starburst effect after a month or a few days after surgery? very weird why i didnt have any until a month after surgery?

the reflections can be frustrating. i dont see the arc shape but kind of like reflection off if glasses but on the side of my eye. it happens when there is a window of light or light source at my side and certain angle. I guess this is something I have to live with?

My recollection is that I noticed the starburst effect right away. I do not think it has gotten better or worse. One possible cause of it getting worse over time is the development of posterior capsule opacification (PCO). Normally this happens over several months or years, not in a few weeks after surgery, but there are cases where it does develop quite quickly after surgery. You should ask if they can see any evidence of PCO at your next eye exam. This is something that can be corrected with the YAG laser process, but should not be done unless necessary.

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There is no easy fix for the reflection issue, if that is what it is. The hope would be that it decreases over time. As we age our pupil gets smaller, and that should also help, but of course that will take a long time.

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As a reference you may want to google this article. What I see as a starburst is best illustrated by the very right hand image in Figure 6. However, the intensity of the starburst is not nearly that bad as what is shown in the illustration. I also notice if I look really carefully that the colour of the spikes of the starburst change, and even move up and down the length of the spike. This is when looking at LED headlights at night. I really don't see it with standard headlights.

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"Ophthalmology Times Troubleshooting post-presbyopia IOL complaints July 25, 2018 Daniel H. Chang, MD"

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Hope that helps some,

As your eye heals the capsule surrounding the IOL contracts-- the natural lens that was removed was larger than the IOL that replaced it. I think it is possible to get some wrinkles or folds in the posterior capsule as it heals, which may in turn cause starburst effects like what you describe. The fix for that would be YAG, but it can't be done until the eye fully heals, and as Ron said it should not be done unless it is definitely necessary.

The effective lens position refers to where the IOL ends up in the eye after healing. The IOL can become decentered, tilted or rotated from the initial position it was in just after implantation. High myopes are more likely to experience IOL rotation and/or decentration than people with normal eyes. Since you did not receive a toric IOL, rotation would not matter. And tilt, if it were to happen, would affect you less than those people with normal eyes because your IOL has a relatively low power of +9D. But decentration could cause you to experience the positive dysphotopsias that you describe as "reflections" as light hits the edge of the IOL. It would be more likely to happen in low light when you pupil is larger. As you age your pupil gets smaller so it should become less of a problem over time.

i feel the reflection happens in brighter lighting as well.

the light streaks are different than the reflection...

What are the grading of both your cataracts? are they eqully bad or one is worst than the other?

From my perspective, the left eye cataract is much worse than the other but the surgeons grade them the same. The OCT machine that they use to look at the retina cannot get a clear view through my left cataract but it can still get a clear scan of my right retina so the machine backs up what I am seeing. My cataracts have progressed much more rapidly than normal cataracts do. I asked what type of cataracts I had but was only told that it was more than one type or a combination.

Ron,

Do you see the starburst in one eye or two eyes? since you have a year in between eyes, do both eyes develop or heal similary after surgeries?

The starburst effect is the same in both eyes. I have about 18 months between eye surgeries, and I would say, as much as I can remember that both eyes healed at the same rate. Vision was pretty much settled at 3 weeks and fully settled at 6 weeks.

i still have reflection at the lower corner of eye and if tyere is a loght source on my left side, i feel the light reflection on my peripheral too. doctor says this will decrease overtime. i wonder when you mean settled at 6 weeks, do you mean your refraction or no longer have those weird reflections?

For reasons I don't quite understand I did not get the peripheral flashes until I got the PVD about a year after surgery. My doctor and optometrist keeps blaming the PVD process for causing the flashes. I am not so sure.

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When I say settled at 6 weeks I am just referring to overall vision not changing.

PVD can cause flashes that are seen when moving the eye quickly in low light environments. This is because the vitreous is tugging on the retina when you move your eye quickly causing you to perceive a flash of light that is usually only noticeable if there is not much ambient lighting.

What you describe sounds more like a light source from the side shining into your eye from a specific angle and causing you to see positive dysphotopsia from your IOL. It's easy to test though-- when you move your eye quickly you'll see the light flash caused by PVD in a dark room even when there are no light sources. This type of flashing light should resolve on its own once the PVD are complete in both eyes

I have the PVD light flashes on my undone eye. PVD started around august of 2023 and i got a bog floater with it. Since Dec, the light flashes started again and until now, they ate there everytine i look on the sifes of eye. is there a problem going through cataract surgery with the light flashes still active?

Yes, I understand how the PVD can cause flashes. I have given up trying to diagnose whether they are positive dysphotopsia or PVD initiated. Sometimes I don't even know which eye is the issue. When your eyes are closed it is hard to tell which eye is acting up. The most consistent time when it acts up is in a dark room with a light on in another room. That is when I notice it, without doing anything to initiate it. I don't see it when I walk around in a dark house with no other lights on. I somehow think I am getting both effect. But, the bottom line is that for me it is more of a curiosity than anything else. I certainly do not see any flashes in daylight conditions or when all lights are on in the house.

I asked this question of my retinal specialist and was told that doing cataract surgery on an eye with a complete PVD is lower risk for retinal detachment than doing the same surgery on an eye that has either a partial PVD or has not yet started the PVD process. The changes that happen after cataract surgery can cause PVD, usually within one year of the surgery. I believe I read this is due to forward traction on the vitreous as the capsular bag shrinks after surgery. (The IOL is smaller than the crystalline lens that was removed.) When this happens the eye is at risk of retinal detachment. My retinal specialist thought the natural process of PVD was also risky for retinal detachment, especially in a high myope. But the least risky was to have the PVD happen first naturally and then have the cataract surgery after the PVD is complete.

However, because there are also risks associated with having poor vision from cataracts (risk of falling, risk of not being able to safely drive a car, etc), an incomplete PVD is not considered risky enough to delay surgery for visually significant cataracts.

Thanks Ron. I've learned so much from reading about your and others' experiences on this forum. I feel so lucky that someone with your level of experience and understanding devotes your time to answering questions and sharing your wealth of knowledge. Thank you!

Thanks for the complement. I try to help when I can, but I sure do not have all the answers!

the light flashes in my operated eye happens during day time so i am pretty sure they are not the PVD flashes. in a dark room, i dont have the light flashes in operated eye but in my non operated eye, i have those from PVD

i did check with retinal specilist before my surgery. he said i have PVD in both eyes. bit he said it is difficult to tell whether a PVD is complete or not. He said they usually can tell whether it has happened or not. he did say the risk of retina detachment is lower past 6 months of PVD. so far, my undone eye has past 6 months but i am still seeing the light flashes in dark room. so i worried!

Ka,

if i remember the IOL you will be using, it has a 7mm optics? i just read that 7mm optics seem to have the best reduced positive dysphotosia! unfortunately i dont think the lens you chose is abailable in the US. are you doing your surgery in Europe? is that a European IOL?

I would agree that light flashes during daylight is highly unlikely to be PVD flashes. Most likely positive dysphotopsia.

I read one study that found 67% of patients reported signs of positive dysphotopsia following cataract surgery. However, by one year after surgery only 2.2% report PD symptoms. So, there is hope that the issue will resolve by itself. I have also seen one study that reported some people got relief from the implantation of a piggyback lens outside of the capsule. That could also make a further correction to your refraction if desired. But, it is not a sure thing, and probably would be quite expensive. Rayner makes a Sulcoflex lens for this purpose, and you would have to find a surgeon experienced in using this type of lens.

My PVD took a very long time to be complete. The process started when I was just 28 years old and finished this past year when I was 48 years old. I think it must have started young and then taken so many years because of my extreme myopia -- I have axial length of 31-32mm. I do not have normal eyes.

I still have flashing lights but nowhere near as much as I used to-- I have to move my eyes very quickly and then I see just a little flash. I use to see flashes without trying and they felt more like lightning.

yes I have decided to travel to Europe for the German-made 7mm IOL, the HumanOptics Aspira-aXA. If you are interested, there is an eye hospital at Heidelberg University in Germany that gets a lot of international patients, especially from Asia.

i sure hope my PD will resolve over time. Streaks are longer and really becoming an issue driving at night. walking is worst when the car headlights are oncoming.

how do you know your PVD is complete? so the flashing light is still there after PVD is complete?

for me now, i see flashing light if i look to the right quickly. a few times, i notice flashing light without looking to the side. The retina specialist said he can only tell i have PVD but cant say if its complete.

do you know which surgeon will be doing your surgery? how did you finally decide on this doctor and lens? How do you arrange your accommodation?

I think I will feel more comfortable with a local experienced doctor. My surgeon has done lens exchange so i feel he is experienced or skillful since not many surgeons are willing to do lens exchange.

**how do you know your PVD is complete? so the flashing light is still there after PVD is complete?

I know because my opthalmologist told me when she was examining my eyes. I also looked back through my medical records to see what they wrote regarding PVD.

Yes I still have some flashing, but nothing compared to the lightning like flashes that I had while the PVD was ongoing. I can definitely see a difference and I'm no longer anxious about it. I think for most people the flashing lights resolve completely when PVD is complete but my eyes are not normal.

Ron,

optometrist did a refraction for me at 5 weeks, spherical is -1.0 and cylinder -0.25. He said my eye might still be improving as he oikes to wait 6-8 weeks before doing glasses.

one thing he mentioned is that the axis of my -0.25 astigmatism is in the same 2'o-clock to 8o'clock direction of how i see light streaks. He said its difficult to tell if my -1.0 myopia contribute to the light streaks.

I havent discussed my second eye target with surgeon yet. but will do that pn 3/11.

A cylinder as low as -0.25 D is so small it is almost negligible. I really doubt it has anything to do with your light streak. I have -0.75 D in both eyes and I don't see any streaks like you describe. The -1.0 D of sphere should not contribute to it either. That is going to make your distance vision less sharp, but should not cause streaks of light.

Your current spherical equivalent is now -1.125 D. I recall your target for this eye was -0.6 D, so that is an miss of about 0.5 D, which is right on the limit of the normal expected +/- 0.5 D range of error.

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I ran the Barrett Universal II calculations again and adjusted the A constant until it predicted your left eye outcome of -1.125. The normal A constant for this enVista lens is 119.3. With your previously reported outcome of -1.50 D I had to adjust the constant down to 117.3 which is quite a substantial adjustment. Now to have it predict -1.125 I had to adjust it to 118.8, which is quit a bit less.

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With this adjusted A constant of 118.8 the Barrett formula now indicates this for the right eye:

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+8.0 D gives 0.0 D SE

+8.5 D gives -0.32 D SE

+9.0 D gives -0.64 D SE

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The +8.5 D would be the right choice for distance vision, but unfortunately I understand 0.5 D steps are not available in the enVista series below a power of +10.. That would leave a choice between the +8.0 and +9.0 D. +8.0 D would be a risk of going hyperopic. So, the +9.0 would seem to be the reasonable choice.

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Hope that helps some. If you get another refraction update I can run the calculation again. However, I would expect at 5 weeks the eye would be pretty much settled down...

Hi Ron,

opometrist said they usually wait 6-8 weeks to refract so i will go in on 3/12 to get a temporary glasses made.

That is a prudent thing to do. You want a stable refraction as the basis for your decision on the second eye. And, no sense wasting money on an eyeglass prescription that does not last. I got my most recent glasses after the first eye surgery, and then just replaced the one lens after the second surgery was done. It is a significant savings in the cost to just replace one lens compared to a whole pair of glasses and frames.

Here is a Barrett Universal II calculation sheet that shows the predictions for refraction outcomes with an adjusted A-Constant. I adjusted the A-Constant until your left eye outcome matched what you actually got - about -1.1 D. Then the same A-Constant was used to make the predictions for the right eye. The suggested A-Constant is 119.3, and I needed to adjust it to 118.8.

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The one downside of considering a different lens than the enVista in the second eye, is that you would have no actual outcome for that lens to predict what the second eye would be like. Same with switching surgeons. A different surgeon may use a different technique in the surgery, and get different results. That is why surgeons often keep their own records and adjust the A-Constant for themselves.