Starbursts and night vision

[richbron]

I suffer from terrible starbursts and generally poor night vision post my lasik (most probably due to the HOA).

I have heard of drops you can put in your eyes that constrict the eyes and help with the starbursts.

What is the name of this - is it an over the counter?

When driving I find if I turn the map light (interior) light on, the starbursts immediately disappear - quite amazing.

I had lasik in NOv 2005, is there any hope the starbursts will disappear on naturally?

[JPD]

I have heard of drops you can put in your eyes that constrict the eyes and help with the starbursts.

What is the name of this

Alphagan P

is it an over the counter?

Not sure, but I don't think so.

I had lasik in NOv 2005, is there any hope the starbursts will disappear on naturally?

Very unlikely

[LasikExpert]

The probability of your nighttime starbursting from light sources resolving on its own after 18 months is not very high, but is possible. You would probably require additional treatment or management. To understand why this occurs, visit our article on Lasik starburst causes.

Keep in mind that higher order aberration (HOA) is a measuring system, not a cause. HOAs don't cause vision problems, they are simply reporting the results of the cause.

The eye drop medications that temporarily reduce the size of your pupils are Alphagan P or pilocarpine. Alphagan P is actually a glaucoma medicine and tends to be less traumatic on the eyes. Both are by prescription.

Starbursting can be caused by residual refractive error or the center of the cornea having a different refractive error than the outer edge of the cornea. Contact lenses often resolve this problem. Enhancement surgery may be considered appropriate. Explore these possibilities.

[richbron]

The probability of your nighttime starbursting from light sources resolving on its own after 18 months is not very high, but is possible. You would probably require additional treatment or management.

Thanks Glenn - what does management of involve. I am not sure if I can undergo another procedure (I have had LAsik AND Astigmatic Keratotomy and I am still wearing glasses).

Are RPG the best lesnes post Lasik and do they assist in addressing or minimising night time starbursts - would they assist in improving night vision.

I have tried regualr soft torics, and the fit is okayish from a comfort perspective, however the vision I get from the lenses is poor in day or night, particularly close up work. What would the reason for this be?

Thanks
Richard

[LasikExpert]

Are RPG the best lesnes post Lasik and do they assist in addressing or minimising night time starbursts - would they assist in improving night vision.

Rigid Gas Permeable (RGP) contact lenses help resolve vision problems with a combination of superior corrective optics and the ability to smooth an irregular cornea and in some cases reduce the effects of dry eyes. An irregular surface can cause starbursting. Dry eyes can cause starbursting. RGPs are something to consider.

I have tried regualr soft torics, and the fit is okayish from a comfort perspective, however the vision I get from the lenses is poor in day or night, particularly close up work. What would the reason for this be?

It may be that with glasses or no lenses at all you are slightly myopic (nearsighted, shortsighted) and this improves your near vision at the cost of distance vision. With contact lenses you are fully corrected and lose the relative advantage of myopia. It may be that the contacts are overcorrecting you into hyperopia (farsighted, longsighted) vision and this is causing near vision difficulties. In either case, an adjustment of the contact lenses would seem in order.

[richbron]

Rigid Gas Permeable (RGP) contact lenses help resolve vision problems with a combination of superior corrective optics and the ability to smooth an irregular cornea and in some cases reduce the effects of dry eyes. An irregular surface can cause starbursting. Dry eyes can cause starbursting. RGPs are something to consider.

The fact that the starbursts disappear when I switch on the interior car light, does this not indicate potentially that my dilated pupil is larger than the operated zone, rather than having an irregular corneal surface?

Would RGP lenses assist in this situation?

has anyone out there worn RGPs - how long did the comfort factor take and how many hours a day is the tolerable level?

I have undergone Lasik and Astigmatic Keratotomy - I do not remember the poor night vision post lasik, so I am guessing that this was post the AK (which was done 4 months after Lasik in Mar 2006).

My residual prescription is
L: +.25 -1.00 (x43)
R: -0.25 -0.75 (x12)

The Vision in my right (lower astigmatism) is particularly bad and I am TOTALLY dependent (on this small prescription) on glasses. The vision in both eyes is so poor that I am not able to read without glasses. Distance vision is impossible without glasses - eg road signs are only visible once I am passing them (without glasses).

My night vision (with glasses obvioulsy) is very poor and I struggle to read number plates of car directly in front of me. I experience huge starbursts (crosses on the light as big as the street pole it sits on).

Would these problems be resolved with RGP - I have tried regular soft torics and the vision is simply not good enough and I suffer from headaches due to the eye strain.

My pre op prescription was astigmatism of -5.75. With hindsight I was much better off at that prescription as I was fully corrected night and day. I was very happy with contact lenses, however these were ordered from Ausatralia (I live in South Africa) and took up to 9 months to order - I used to wear a pair for 5 years at a time.

I am considering being fitted with RGP and would be interested in feedback regarding level of comfort from patients who have/do wear them and whether they would address my night vision concerns.

Thanks
Richard

[LasikExpert]

The fact that the starbursts disappear when I switch on the interior car light, does this not indicate potentially that my dilated pupil is larger than the operated zone, rather than having an irregular corneal surface?

Yes, this strongly indicates that there is an imbalance between the size of the fully corrected portion of your cornea and the size of your naturally dilated pupils.

Would RGP lenses assist in this situation?

Quite possibly. If appropriately fitted they can help correct the refractive error at the outer edge of the cornea.

has anyone out there worn RGPs - how long did the comfort factor take and how many hours a day is the tolerable level?

I assume this is an open question to anyone who has worn RGPs after Lasik. I can tell you from others' experiences that they range from some discomfort to not know they are in. Much depends upon the skill of the lens fitter.

My residual prescription is
L: +.25 -1.00 (x43)
R: -0.25 -0.75 (x12)

A prescription is inadequate to represent your vision difficulties. Your script shows simple refractive error that would be able to be corrected with glasses. I suspect that what you have is irregular astigmatism (uneven corneal surface). This is where RGPs seen to be very helpful by smoothing the corneal surface.

[richbron]

My residual prescription is
L: +.25 -1.00 (x43)
R: -0.25 -0.75 (x12)

A prescription is inadequate to represent your vision difficulties. Your script shows simple refractive error that would be able to be corrected with glasses. I suspect that what you have is irregular astigmatism (uneven corneal surface). This is where RGPs seen to be very helpful by smoothing the corneal surface.

I assume that a wavefront topography would highlight any sort of irregular astigmatism, however, the Doctor suggested he found nothing untoward from a vision point of view on the Topgraphy reading.

He suggests that my the poor quality of my vision (long and short vision) is either due to spherical equivalent (SE in Right eye is -0.625) - Right eye is the poorer quality of vision; or could be the fact that I was -5.75 astigmatism and my eyes has not adapted yet.

I am not convinced either way - he did comment that my HOA were very high (particularly the Right eye) - this should be the clue.

On my mild prescription (after 2 prcosedures) I still totally dependent on glasses all day and night (although night vision is seriously hampered).

I plan to go see him again as I simply cannot continue with the poor quality of vision I have with glasses (day and night but particularly bad at night). What other tests should he be conducting.

Its strange, my right eye if I look in different directions (eg up through the top of my eye) my vision improves - does this indicate central islands?

The Doctor I went to is renowned for his skill and has a fantastic name in the business.

Having had Lasik and an AK (my cornea is think enough) would there be any benefit in having wavefront Lasik to address the remaining refraction and to address the Starbursts - or is there a danger that this could aggrevate it further and result in the quality of my vision reducing ??

I think the advice on this site is outstanding - thank you

Richard

[LasikExpert]

I assume that a wavefront topography would highlight any sort of irregular astigmatism, however, the Doctor suggested he found nothing untoward from a vision point of view on the Topgraphy reading.

Topography and wavefront analysis are quite different. Topography (often with an Orbscan) measures the elevation changes on the front and back surfaces of the corena. It is a topographical map.

A wavefront analysis sends light into the eye that bounces off the back of the eye and comes out. The changes through the entire optic of the eye are measured by the changes caused to the light. Think of a square grid of light going in and a wavy grid of light coming out. Measuring the difference between the square and the wave measures the aberrations of the optics of the eye.

He suggests that my the poor quality of my vision (long and short vision) is either due to spherical equivalent (SE in Right eye is -0.625) - Right eye is the poorer quality of vision;

What the doctor probably meant was Spherical Aberration (SA), which is the common description for a type of optic aberration presented in Zernike polynomials. Described simply; SA means you have a different refractive error in the center of your eye than you do at the outer edge. Elevated SA would be consistent with your night vision problems. Normal SA is around 0.30-0.40. Your SA is clearly elevated. The larger your pupils the greater the elevation of your SA, so your pupils would need to be fully (naturally) dilated to get a true reading.

or could be the fact that I was -5.75 astigmatism and my eyes has not adapted yet.

This may be true to some amount. You may want to read about Lasik eye strain.

I am not convinced either way - he did comment that my HOA were very high (particularly the Right eye) - this should be the clue.

Remember that HOA are only a measurement of the problem, not the problem itself. Like all measurements, some conclusions may be able to be derived from the information. Elevated SA indicates a difference between the fully corrected optical ablation zone and the size of your naturally dilated pupils. A possible resolution would be enhancement surgery to enlarge the optical ablation zone, or Rigid Gas Permeable (RGP) contact lenses to help reshape the cornea and create a more uniform refractive error.

On my mild prescription (after 2 prcosedures) I still totally dependent on glasses all day and night (although night vision is seriously hampered).

Your vision problems are not so much about Lower Order Aberration (LOA) refractive error - which can be corrected with glasses. They are more about the aberrations in your optic system that reduces the quality of vision.

I plan to go see him again as I simply cannot continue with the poor quality of vision I have with glasses (day and night but particularly bad at night). What other tests should he be conducting.

Seeing your doctor again is a good idea, but it appears that your doctor may have reached the limits of his ability. I recommend a second opinion. A corneal specialist at a university affiliated teaching hospital may be most appropriate.

Its strange, my right eye if I look in different directions (eg up through the top of my eye) my vision improves - does this indicate central islands?

Not necessarily, and central islands tend to show up on the topography maps rather well.

The Doctor I went to is renowned for his skill and has a fantastic name in the business.

It is a sad fact of surgery that even the very best doctors can have poor outcomes. Since your doctor is well respected, I suggest that you ask him for a referral to a different specialist to evaluate your situation.

Having had Lasik and an AK (my cornea is think enough) would there be any benefit in having wavefront Lasik to address the remaining refraction and to address the Starbursts - or is there a danger that this could aggrevate it further and result in the quality of my vision reducing ??

Wavefront-guided enhancement to resolve vision problems as you describe may be helpful, but what is not clear is exactly what is causing your poor vision. The measurements and symptoms show something is wrong, but it seems your doctor has not yet determined exactly the cause. Without knowing the cause, the cure is difficult to determine.

A limitation of wavefront-guided ablation is the limitation of the treatment area. Most lasers are limited to about 6.0mm diameter full correction zone, and this becomes smaller for astigmatic correction. Due to your SA measurement it appears that what you need is a larger treatment area. This may require conventional ablation.

I think the advice on this site is outstanding - thank you

Thank you for your kind words.

[richbron]

Hi Glenn

A final questions from me - I have a Doctor's appointment on 23 July so will feedback after that ....

My vision quality problems only really seemed to bother me after I had an Astigmatic Keratotomy (I had this post Lasik). My question ....

1. Can AK increase HOA levels?
2. The Starbursts and night vision quality seem worse in the evening dark - as opposed to driving in the dark first thing in the morning. What is the cause of this?

Once again thank you for all the advice and will feedback post July (wife is having baby No2 between now and then...)

Regards
Richard

[LasikExpert]

First and foremost, congratulations on baby number two!

1. Can AK increase HOA levels?

Any surgical manipulation of the cornea can change the optics of the eye and thereby change the measurable levels of HOA.

2. The Starbursts and night vision quality seem worse in the evening dark - as opposed to driving in the dark first thing in the morning. What is the cause of this?

That is interesting, but I don't know of a scientific reason for this phenomena. If the light amount is the same, then one would expect the visual quality to be the same. The only thing I can think of is that you and your eyes are more rested first thing in the morning. That is assuming that you were not up all night.