Many questions regarding my upcoming 6 month exam later this

Post your questions and start your research in this forum if more than three months ago you had any type of surgery to reduce the need for glasses and contacts.

Many questions regarding my upcoming 6 month exam later this

Postby ConfusedInNY » Fri May 09, 2008 9:45 pm

Yes I know it will take time to read but please do so .So I don't overwhelm the director who's email I have on file. If you can help me narrow this to questions that are most important before I send it , It would be greatly appreciated.

I noted footnotes to what I read and quoted sources which I read off this site. I will address new stuff I found on this site afterward.

Please help!

Halos and Glare

Recently, the media has placed significant attention on night vision disturbances like halo and glare (halos and glares) following refractive surgery. In some cases, this problem has been blown out of proportion. Most patients, including those that have not undergone refractive surgery, experience greater vision difficulty at night than during daylight hours. This has to do with the pupil getting larger in the dark. As the pupil gets larger, the optical quality of every eye worsens. A large pupil makes any uncorrected refractive error more apparent while also introducing the vision-degrading effects called spherical aberration and coma. This leads to the perception of “glare and halos” even in patients that have not had refractive surgery. Patients wearing contact lenses and glasses may also note additional “glare and halos” from the extra reflecting surfaces introduced by these corrective lenses.

The vast majority of LASIK patients experience at least some temporary glare and halos during the immediate recovery. This can last for weeks and is due to corneal swelling and reorganization of the corneal architecture. Patients in the healing phase need to understand this is normal and different from the persistent variety of night vision problems.

Persisting glare and haloes after LASIK have several possible causes. The most common is “residual refractive error”, which refers to remaining myopia, hyperopia, or astigmatism from under- or over-response to the treatment. In these cases, a pair of prescription glasses or a surgical enhancement can solve the problem. Glare and halos may also occur if the pupil enlarges beyond the area of laser treatment or when there is a decentered ablation. When either of these exist, light can bend irregularly at the junction between the treated and untreated cornea. If the pupil is large enough, the irregularly bent light passes into the eye, causing glare and haloes. Since the pupil gets larger in the dark, glare and haloes are usually most noticeable at nighttime.

There are several treatments for pupil-related night vision problems although none are perfect. Driving at night with the dome light on can help constrict the pupils although this practice is not legal in certain states. Alternatively, your doctor can prescribe an eye drop called pilocarpine to shrink the pupil. In certain patients, this drop may cause focusing spasm and increase the risk of retinal detachment. Another eye drop for shrinking the pupil is called dapiprazole. This drop makes the eyes appear red and stings on instillation. Other drops are under investigation. Eye color-changing soft contact lenses (with an annular ring of color) may reduce glare and halos by making the functional pupil smaller. "Over-minused" or over-powered corrective lenses may also cause the pupil to reduce in size. Some surgeons have suggested performing an enhancement procedure using a laser to enlarge the original treatment zone.


High degrees of myopia and/or astigmatism can create a sharper junction zone between treated and untreated cornea to potentially scatter light. Hence, when the pupil size and prescription are considered together – not separately – your doctor should be able to tell you whether your are at low, medium, or high risk for developing this type of glare and halos. High risk patients may benefit from lasers using a larger treatment size and from upcoming technology.

- Excessive Corneal Haze: Corneal haze occurs as part of the normal healing process after PRK. In all but a few cases, it has no effect on the final vision and can only be seen by an eye doctor with a microscope. However, there are some cases of excessive haze that interferes with vision. As with undercorrections, this can often be dealt with by means of an additional laser treatment. The risk of significant haze is much less with LASIK than with PRK.



Source http://www.afterlasik.com
reported Johnny L. Gayton, MD



My notes : It is extremely uncomfortable , but I deal with the starbursts , bright lights day or night
when I left your office last time . I began to question the starbursts when we left and went into hotel lobby elevator
elevator next door to go downstairs and pick up the car to go back to US.

I saw last month on ABC News about the problem which I currently experience. They were talking about peoples
problems after lasik surgery. They demonstrated exactly the case that I have. Now I'm 100% sure, no more questioning
about what I viewed online or the questions I was asked by you and the center. You see they showed car lights and street
lights. The street I live on when looking out the window I see exactly what they showed on tv. I am unclear about halos.
As I knew when I'd fall asleep once in about 10 yrs with my contacts on I got a halo effect caused from the accumulation
of I think dirt,and the dryness of the eye.I believe thats why they say never to fall asleep with them in. I know that
I had no starbursts, nor knew of what one was before lasik.
I don't believe that the condition is worse at night .The reason is I try taking my protective eyewear off in Walmart and find the
starbursts to be severe, and the light is way too bright for me to adjust to. For this reason I do wear the glasses
whenever I expect to be in bright lighting conditions. Give an example my bldg here shows movies downstairs
from Jan to May on Sat nights. I go as often as I can. At first I have to wear them during the movies. Midway between
when I last saw you and now I was able to take them off for a part of the movie. I notice in dark light I am fine staring
at the big screen. However in bright lights while watching I do have to put them on for a few seconds til the scene
goes inside and therefore darkens. While I sit here I will tell you which lights in my apt affect it, and which don't seem to
the cable box with green is it florescent light? does somewhat. The ceiling reg bulb doesn't. The kitchen light with a dim
type bulb doesn't. The light above my medicine cabinet does severely it causes that black dot I told you about.
While typing on my pc I can read, that's not the problem but the starburst I know is there, I believe this is creating what I
think is a black dot. giving the eye the feeling there is a patch over one of them. In fact I just used the window
looking out over my busy street (as an eye chart by covering each eye individually and testing if it was worse or the same in both eyes) as the cars go by and the street lights . It appears to be equal, no better or worse from left to right eye.
At this time I am 60/40. 60% happy that I can take a nap, or do things I wouldn't do without my contacts in. I am also
happy to be able to see in shower, I see things crisper than even with contacts like the tv, pc,etc. Now the 40%
I still am less than happy that the effects have not gone away nor gotten any better since my 3 month visit. The only
change in which your right about is that I feel more confident reading some smaller print from both eyes. I guess they have become stronger.

I read something about the pupil gets larger in the dark after lasik, and that can affect vision in starbursts. what about in light
is same true, or is it different? . Do you know if I am getting corneal swelling or not?

The same condition as I tried to describe while sitting in your office is still the same as it was back then. I did not know
exactly what it was called, only the symptoms I described to you.

Is 6 months an avg, or does it sometimes take a few more months up to a yr til one knows if the eye has permanently
healed from the surgery? How can your doctors tell me with certainty when/whether I achieve this result?.
I do feel it is important not to rush the human body to heal. So I will give the benefit of my doubt that maybe
some more time is necessary before figuring out what the correct method to correct this problem once in for all is.
I do hope that once I give the time necessary where you can verify that is has gotten to the best it should then
I think based on what I read that I might benefit from some form of enhancement, whatever it will take to make me
fully operational ,and confident in what I see all the time, not some of it. I don't want to depend on friends to help
me I want to do it all for myself in any lighting condition.

What size are my pupils do you know?
What is Epithelial ingrowth? , do you know whether or not it could apply to me?
Are there or could there be any problems with the flap?. Can you find out for me my results.
What do they mean enlarge the treatment zone? . How does one benefit from that?
Are all my blood vessels in my eye normal?

Higher-order aberrations are visual problems not captured in a traditional eye exam which tests only for acuteness of vision. Severe aberrations can effectively cause significant vision impairment. These aberrations include starbursts, ghosting, halos, double vision, and a number of other post-operative complications listed below.
This correlation is the result of the irregularity between the untouched part of the cornea and the reshaped part.

My comments : Is this what I'm experiencing?

Over time, most of the attention has been focused on spherical aberration. LASIK and PRK tend to induce spherical aberration, because of the tendency of the laser to undercorrect as it moves outward from the center of the treatment zone. This is really a significant issue for only large corrections. There is some thought if the lasers were simply programmed to adjust for this tendency, no significant spherical aberration would be induced. Hence, in eyes with little existing higher order aberrations, "wavefront optimized" LASIK rather than wavefront guided LASIK may well be the future

Whats the difference? which wavefront did I have?



In any case, higher order aberrations are measured in µm (micrometers) on the wavescan taken during the pre-op examination, while the smallest beam size of FDA approved lasers is about 1000 times larger, at 0.65 mm. Thus imperfections are inherent in the procedure and a reason why patients experience halo, glare, and starburst even with small naturally dilated pupils in dim lighting.

I'm still trying to understand what spherical aberration is? They keep on talking about it with Wavefront-guided LASIK.


Wavefront-guided LASIK[4] is a variation of LASIK surgery where, rather than applying a simple correction of focusing power to the cornea (as in traditional LASIK), an ophthalmologist applies a spatially varying correction, guiding the computer-controlled excimer laser with measurements from a wavefront sensor. The goal is to achieve a more optically perfect eye, though the final result still depends on the physician's success at predicting changes which occur during healing

Hmmm sounds like predicting the weather. Which even with numerous computer models they seem to be right only about
half of the time.

Complications
A subconjunctival hemorrhage is a common and minor post-LASIK complication.

The incidence of refractive surgery patients having unresolved complications six months after surgery has been estimated from 6%[5] to 12%.[6] The risk for a patient of suffering from disturbing visual side effects like halos, double vision (ghosting), loss of contrast sensitivity (foggy vision) and glare after LASIK depends on the degree of ametropia before the laser eye surgery and other risk factors.[7] For this reason, it is important to take into account the individual risk potential of a patient and not just the average probability for all patients.[8] The following are some of the more frequently reported complications of LASIK[9][5]:

* Surgery induced dry eyes
* Overcorrection[10] or undercorrection
* Visual acuity fluctuation
* Halos[11] or starbursts[12] around light sources at night
* Light sensitivity
* Ghost images[13] or double vision
* Wrinkles in flap (striae)[14]
* Decentered ablation
* Debris or growth under flap
* Thin or buttonhole flap [15]
* Induced astigmatism
* Corneal Ectasia
* Floaters
* Epithelium erosion
* Posterior vitreous detachment[16]
* Macular hole[17]

Can you tell me do any but starbursts exist with me?.
I feel I need a degree to understand all this stuff. Yet I am trying hard to, so we all are happy with my results.

Flap interface particles are another finding whose clinical significance is undetermined.[23] A Finnish study found that particles of various sizes and reflectivity were clinically visible in 38.7% of eyes examined via slit lamp biomicroscopy, but apparent in 100% of eyes using confocal microscopy.[23]

Huh what is this?

What is normal for tears as far as eyes go? . Mine seem to be somewhat dry at times even after adding drops.

When the optics are too powerful for the length of the eyeball (this can arise from a cornea with too much curvature or an eyeball that is too long), one has myopia.

Myopia is near sightness? what powers the optics of the eye?


Quality of Vision Complications

Glare/Halos/Starbursts

Another cause is incomplete correction of the nearsightedness, farsightedness or astigmatism ,what is inc corr?


Depending upon the cause, patients who experience significant, persistent glare, halos or starbursts have several treatment options. Enhancement procedures would be an option, but not everyone is eligible for an additional procedure. Eligibility for enhancements depends on a number of factors that a doctor must evaluate

If an over or undercorrection has occurred, the ophthalmologist will discuss your treatment options. Generally, surgeons prefer to wait approximately 6 months to perform an enhancement to ensure that the final vision has been achieved. As that point, either a hyperopia or myopia LASIK procedure will be performed to correct the residual error, if the patient and doctor believe it is appropriate. , how does one determine if it was over or under corrected?

Typically, an enhancement procedure can be performed to correct the residual error, just as is done to treat an undercorrection or overcorrection.
residual error , meaning?



Source : http://www.eyesurgeryeducation.com/Post ... tions.html

Things seem much brighter than they were with contacts. Is this normal? Maybe that's the glare? Maybe I'm mistaking that with crispness.
That is only thing I am not clear with as to facts about what I see.

Many doctors believe that there may be a correlation between wide pupils and decreased night vision, particularly in cases where treatment of high myopia
What does it it mean wide pupils? and ablation zones ,what do they mean?

Patients should ask their doctors about the test they conduct for pupil diameter. Doctors measure the pupil in several ways. Most doctors will measure the pupil in both bright and dim light to simulate day-to-day lighting situations. Some doctors will utilize their experience and measure the pupil without using instrumentation, while others will put a pupil gauge up to the eye to determine the size.

Did we do this in both light and dark? Don't recall


Some patients may experience a decrease in corneal sensation following LASIK for the first six months following the procedure as the nerves of the cornea regenerate. Corneal sensation is characterized by a feedback loop. When the eye is dry, a message is sent to the brain. The brain then stimulates the eye's lacrimal glands to produce tears. However, creating the flap cuts the nerves of the cornea. For some eyes, this process temporarily affects the cornea's ability to sense dryness. When corneal sensation decreases, the feedback loop is disrupted, and the eye will experience dry eye symptoms.

Does this affect starbursts and what I'm going through? How can you tell if it has been regenerated? if this is a concern.


Just did the test on the tv. I thought it seemed okay. However when they use big bold lettering for important points.
I do each eye separately I notice some drag from left eye, but almost like the letter is super imposed and dragged down
on the right eye that is what I mean like double, like I was saying to doctor. I paused my remote tried it again with medium size lettering
It seems dragged down on the right, and slightly down on left ,but also a bit further up. Where right seems only down.
This makes me conclude that it is equal ,just in different areas in both eyes. This is most evident with a plain color
background. It also explains what I tried to express when viewing the eye chart with your doctor. I was at least able
to express the right eye problem. Now I am able to explain the left is equal and why sometimes it seems less evident.

Okay that basically it until my appointment. Just wanted to ask what you think about these things and help me
understand best about what to express at my exam. I figured I'd email this to you. So you can help me focus
on how I can help find a solution ,without having to get a medical degree for this stuff... hehe

Sincerely,
D
ConfusedInNY
 
Posts: 1
Joined: Fri May 09, 2008 7:01 am
Location: NY State

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