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Ways to determine if the glare is due to the edge of IOL or from the rim of anterior capsulorhexis?

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This question is for a cataract specialist. Is there any way to determine if the glare I am experiencing is from the edge of my IOL or if it is from the rim of my anterior capsulorhexis?

I had a Tecnis monofocal +11 D lens model ZCB00 put in my left eye 12/4/12. Surgery uneventful and vision 20/20 afterward. I had Yag to remove a streak due to a posterior capsular fold 5/3/13.

I noticed some faint starbursting before the YAG but not enough to really bother me (the YAG did resolve the streak due to the fold), but immediately after the YAG the starbursting became terrible.

My surgeon and a second one I consulted both say the posterior opening is large enough. I was examined for residual astigmatism and refractive error, but even RGP contact lenses didn't have any effect. Finally, I had some aberrometry testing on the iTrace which indicated my abberations were not from the cornea but lenticular. Above the 5.5mm pupil size my RMS value was 1.5 microns! The number fell to normal values at the 5mm pupil size. The doctor who did this testing also took OCT images and said his best guess was that the glare/starbursting was due to my anterior capsule as the opening is 4.5mm and I have large pupils. I went back to my surgeon and he thinks the starbursting/glare is from the rim of the capsulorhexis (there is some fibrosis he noted.) The 1% pilocarpine drops he gave me resolve the starbursting in the day time. At night the starbursting in my central vision is gone but is terrible from about 35 degrees and outward in the periphery in all directions.

Let me add that I am not one of those "fussy" patients. I don't mind wearing reading glasses and wouldn't even mind having to wear contacts if I'm not 20/20, but this glare is not acceptable. I'm willing to wait 6-8 months to see if I "neuroadapt" but in the mean time, I would like to find out if the source of the glare is the IOL's edge or the anterior capsule rim because the treatment plan will depend on the source. I know lens exchange is more complex after the posterior capsule has been opened but I think I deserve to know all my options.

Thanks very much.
Posted Tue, 6 Aug 2013 in Vision and Eye Disorders
Answered by Dr. N. K. Misra 3 hours later
My dear,
Thanks for sending your query to us.
You have had a good surgery.We want ideally .25 mm of ant,capsule to cover the ant.surface of IOL.
Post. or ant.capsular tags if they are bothering you may be tackled by yag laser.
IOL edge is not supposed to bother you as it too far away from the visual axis.
You should continue with pilocarpine for the time being,as it helps you symptomatically.
do get back to me in case of any further query in this regard.
Above answer was peer-reviewed by
Follow-up: Ways to determine if the glare is due to the edge of IOL or from the rim of anterior capsulorhexis? 11 hours later
Dear Dr. Misra,

Thanks for your response. Other than the .25 mm figure (which is good to know) you did not provide any information that I didn't already know. However, I have to call into question why you disregard the IOL edge as a potential source of glare. I know I'm in no way an expert but I have a degree in Aerospace Engineering and have had enough physics and optic classes to be reasonably positive that light rays obliquely entering a pupil dialated to 5.5 - 6.0 mm at night could hit the edge of an IOL with a 6.0 mm optic zone. Also much has been written in the literature about the trade off between decreased PCO and increased glare with square IOL edges. A simple Google search on IOL edge glare yields dozens of articles on the subject. Here is an excerpt from one:

With relatively simple XXXXXXX tracings, XXXXXXX Holladay, MD, has demonstrated that round edges distribute light rays over a significantly larger retinal area than sharp edge designs. The rounded IOL edge reduces the peak intensity of the reflected glare image by diffusing the reflected light, thus diminishing the potential for unwanted optical images. In contrast, the sharp edge creates a coherent, internally focused reflected image. How patients became acclimated to these images remains poorly understood. For the few patients that do not have resolution, unfortunately, miotic therapy appeared to have no benefit.

According to the last sentence, even constricting the pupil via miotic therapy doesn't resolve the edge glare for the patients that experience it.

Since the rim of the anterior capsulorhexis is essentially an "edge" I would assume it could also produce the same phenomena as the IOL edge. I just want to know how you ophthalmologists would determine if the glare is from the IOL edge or the capsulorhexis edge? If it is from the IOL edge the only solution would be IOL exchange which may or may not work. If it is from the capsulorhexis my doctor said he would either use the yag OR tuck the anterior capsule behind the lens. I can't find any information on the latter technique of tucking the capsule behind the lens.
Answered by Dr. N. K. Misra 4 hours later
My dear,
Thanks for getting back to us.

There are a few things which you should be clear about to begin with.
The square edge is a very recent phenomenon and we had been operating for a very long time before that with regular design. The main advantage of square edge has been prevention of cell migration to prevent PCO.

Now coming to your question specifically:
Practically lens edge does not come in the way of light rays as even in semi-dilated pupil iris border will prevent light rays reaching the lens edge.
Therefore it is the Ant. Capsulorehexis margin or the Yag capsulotomy margin which is the main culprit. The later being the reason if glare occurred after Yag capsulotomy (this is a way to differentiate).

In your case Ant. Capsulotomy edge can be tackled by Yag, if necessary.
Tucking the capsule behind the lens may tilt the lens, thereby producing more problems than solving it.
Above answer was peer-reviewed by
Follow-up: Ways to determine if the glare is due to the edge of IOL or from the rim of anterior capsulorhexis? 6 hours later
What you have said makes sense. Thank you.
Answered by Dr. N. K. Misra 39 minutes later
My Dear,
You are welcome.
Above answer was peer-reviewed by
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