Irregular astisgmatism and cataract

[taurus1203]

Dr Oyakawa,
Just continue the discussion on the irregular astisgmatism and cataract  you mentioned
The cataract surgeon I met last week just told me that I need more testing to ensure my problem is from the cataract before making the decision for a surgery.

I have astigmatism prescription in my glasses. Recently, I was tested by 2 optometrists/eye doctors with 2 eye exams each last for more than 1/2 hr. With the best correction of the lens including myopia and astigmatism, I can only see 20/50. But I can see a pin hole with 20/25. The eye doctor in the clinic then draw the conclusion that my current limit is 20/50 and if removing the cataract, my vision can become 20/25 or better. His explanation is that a pin-hole test is like a PAM test where the image will not be disturbed by the cataract.

Do you mean I should I ask for another evaluation using corneal topography to ensure there is no uncorrected astigmatism ?  
How likely is that the cataract limit my vision to 20/50 and there is no way to correct by lens ?

When I look distant object (more than 30 ft)  like the signs in the shopping mall, my surgery eye see the letters a little bit double vision. It will be when I walk closer.
I always thought this is the result of the cataract. Is it possible the astigmatism ?
Is the corneal topography available in optometrists ? Or only available in big eye institute or hospital ?

Thanks

[taurus1203]

I plan to remove the cataract asap. Just waiting for the appointment for my retinal surgeon to get his green light to go. Would you please tell me the benefit to do it now compare to 1 year later ? I know he will try to convince me to do it later and I would like to have reasons to support me to do it now.

Why do you think I have more risk ? Isn't it that I have less risk of detachment as my previous vitrectomy clean up the liquid and that reduce to traction to the retinal ?

Thanks

[Ray T Oyakawa, MD]

Yes, it is worthwhile to take out the cataract now.  It will be hard to remove in the future and you already have an increase risk in complications due to your previous vitrectomy.  The vision could be better than the pinhole if there is no irregular astigmatism in the cornea.

A toric can not correct irregular astigmatism.  Irregular astigmatism is hard to correct.  However, it is most common after RK  or LASIK and is rare corneal diseases.

Dr. O.

[taurus1203]

Dr Oyakawa,
Thanks for your info first.
I am going to see an eye doctor soon to sort out these issues.
If this is proved there is a irregular corneal astigmatism and my vision will be improved a bit (like to 20/32), is it still worthwhile to consider the cataract surgery as my pin-hole is only 20/25.  Or you think my after cataract surgery vision may be better than pin-hole.

Can toric IOL correct irregular corneal astigmatism ?

Thanks again

[Ray T Oyakawa, MD]

A pinhole can improve vision in a cataract but usually not from 20/50 to 20/25.  I would use a hard contact lens to rule out irregular astigmatism of the cornea.   There is a near pinhole test (RAM) that works similar to a PAM.  However,  it will not rule out irregular astigmatism.  Double vision is usually due to astigmatism.  It can be in the cataract or the cornea.

Corneal topography is a routine piece of equipment.  However, if he does not have one a hard contact lens over refraction will determine if irregular corneal astigmatism is contributing to the decrease in vision.

Dr. O.


Dr. O.