6 month post membrane peel. Time for cat surgery IOL choice

[GrandKK]

I had macular pucker surgery 6 months ago. Results are mixed. Acuity hadn't changed much at 3 months, still 20/50 then cataract began so I really don't know current potential acuity. It is now 20/70 with cataract.  Distortion somewhat improved in that faces don't look so much like aliens on TV, but words still look like roller coaster when reading. Also have larger image size in that eye. Most troubling is the double vision I get because image in that eye is pulled downward and to the right. It is most noticeable at distances such as headlights and stop lights. I am trying to determine best choice for IOL. I am myopic at -6.00, have worn contacts most of my life but not in recent years. My biggest concern is reducing the double vision so I am wondering if they target surgical eye for -1.50 if that would blur the distance out enough that my good eye could override duplicate image. I've read that in order for that to happen distance vision in problem eye must be reduced to at least 20/60. Would that target give me that?  Right now I find that the diplopia is not severe due to blurring from the cataract. Hopefully I could then wear a contact in good eye and reading glasses when necessary and when cat surgery is due for that eye, prob in a few years, I could have it corrected for distance and be less dependent on glasses. My other choice seems to be correcting surgical eye at less, maybe -4.50 and then continuing to wear glasses. That may give me more options for refining that eye? Current glasses prescription:
OD -6.00 Cyl -50 Axis 140  +2.25
O.S. -6.00 Cyl. -.75 Axis 30  +2.25
I'm still hoping for some improvement in that eye at least for distortion. I know my cataract surgeon will help with decision, but I wanted to run this by the group for input. I learned much from Dr.Hagans's cataract options article. Thanks

[JohnHaganMD]

Auto-correct change  'under drop anesthesia"  they put drops in your eye to numb surface, no shots or injections.   "in the eye exam lane"  done where your eyes are tested not in operating room.

[GrandKK]

Thank you

[JohnHaganMD]

Sure. Not painful and not expensive.

[JohnHaganMD]

First of all with macular pathology like you have its recommended not to do any special IOL like multifocal, accommodating,  Synfony.   You don't have enough astigmatism to warrant a toric IOL. So you best choice is high quality, aspheric monofocal IOL.  What is disturbing is double vision. Cataract should not cause double vision and macular pathology should not cause double vision. I would suggest you ask your cataract surgeon to refer you to an eye muscle Eye MD (strabismologist or also called pediatric ophthalmologist) to find out why you have double vision. Possible that one of your eye muscles may have been injured with your membrane peel.  You can also ask the eye muscle specialist how much difference your two eyes might tolerate.  If your eyes were straight and your unoperated eye has good vision you should not see double and your brain should suppress the blurred image from the membrane peel eye.

[GrandKK]

Thank you Dr Hogan. I've had the double vision for about a year before the membrane peel. Evidently the membrane caused my fovea to be displaced..."dragged fovea"? This pulls the image in that eye downward and to the right which causes binocular diplopia. The larger image size probably contributes also. I'm just wondering how an IOL at -1.50 would translate to distance vision. I'm hoping to not have better than 20/60 so the dominant eye could override the blurred image. Does that make sense. Apparantly prisms don't always work with dragged fovea.

[JohnHaganMD]

I would still suggest seeing a pediatric ophthalmologist. Prisms should work reasonably well because the amount of deviation would remain constant no matter what direction you are looking. Retina surgeons and cataract surgeons rarely have the patience or skills to carefully try prisms.

[GrandKK]

Okay..worth looking into. If prisms would work that would be great. Can you tell me about distance vision with a -1.50 IOL?  Comparable to 20/60?

[JohnHaganMD]

With a normal eye and a refractive error of -1.50 the distance (20 ft/6 meter) is not going to be good probably around 20/100.  It is not an exact science since the size of the pupil can make the vision better or worse. Small pupil will make better, large pupil worse.

[GrandKK]

Had my preop measurements done. Potential acuity post ERM peel appears to be about 20/60. Surgeon is suggesting targeting for near at 2.00 and wearing contact in right eye for distance. Acuity may be okay for reading, but unfortunately words are wavy from ERM, so will probably still need reading glasses. My concern is the distance binocular vision. If potential is only 20/60, with a target of -2.00 could the difference between both eyes be too great to be able to work well together? Would aiming for -1.50 be better? Also, I will be seeing strabismus dr if double vision still a problem after cat surgery.

[JohnHaganMD]

So after surgery you will be -6.00 in unoperated eye and -2.00 in the operated.  With that big of difference and  best expected of 20/50 to 20/60 with distortion  it doesn't make any difference betweeen -1.50 and -2.00   still going to have problems with the eyes working together. Most likely your brain will not pay any attention to the distorted central vision in the operated eye and just use the peripheral vision.  

[GrandKK]

Yes, big difference without contact in good eye, but how big when wearing a contact for distance(plano) in good eye? Technically I would think -2.00, which I could adapt to, but I'm not sure how much the fact that my acuity could be at best 20/50 will factor in. Would rather not have to wear glasses other than for reading.

[GrandKK]

I'm just confused as to whether I should target IOL for distance in order to get best binocular vision or target near because that's where my best vision is.

[JohnHaganMD]

No easy solution for you situation. Suggest you discuss at length with your surgical team.   If your operative eye post op is -2.00 or -1.50 but 20/50 or 20/60 with distortion it's not likely you will be able to rely on that eye for reading . On the other hand we hate to leave an eye post cataract surgery with a -6.00 refractive error.  

[GrandKK]

Thank you for your input. I am meeting with my optometrist tomorrow who is in the same office as surgeon. Perhaps he can add some insight.

[JohnHaganMD]

Good luck

[GrandKK]

Just returned from optometrist. Feel good now about targeting IOL for -2.00 to -1.75. He did a potential acuity test that showed I may get 20/20 vision after cat surgery...that would be amazing. One question came up in that he shows my astigmatism to be slight..-.75 or less, yet my surgeon is planning a toric lens due to his testing showing -1.50. He said he would discuss with him. Do you have any explanation?

[JohnHaganMD]

The measurement of cornea astigmatism can vary from instrument to instrument, or from technician to technician or on different dates. However  that is a 200% deviation and way too big (0.75 vs 1.50)    If you go with a toric IOL I would insist they remeasure, best technician and best instrument till they get consistent readings.   Also I'm not your doctor but in our practice we do not use toric IOLs in patients with significant macular pathology but that's your call and your money.

[GrandKK]

That's interesting. I knew I could not have multifocal, but had not heard about toric not being advised. Hmmmm.

[JohnHaganMD]

I'm not saying every practice feels that way, nor that you should not have it. If your potential Visual acuity is 20/20 and you understand there is about a 1-2% incidence of secondary surgery to rotate IOL it may be okay for you.

[GrandKK]

Update. Cataract surgery went well. Toric lens targeted at 1.75 in left eye  and wearing contact in RE for distance (-6.00) . Pleased to find out membrane peel resulted in LE being correctable to 20/20. Still have some distortion and larger image size. Hoping for more improvement. Biggest obstacle now is dealing with dry eye while trying to wear contact all day and not able to wear glasses as a back up. Cat surgeon is suggesting punctal plugs. I dont know much about them and would appreciate some input.

[JohnHaganMD]

Dry eye is not the term Eye MD use. We call it ocular surface disorder. There are two types:  1. aqueous deficiency. Eye is very dry and doesn't water.  2. Lipid deficiency or evaporative  the eye waters constantly due to poor quality tear. Tear duct plugs helps only the first. Tiny plugs put in the lower tear duct opening (puncta) until drop anesthesia in the eye exam lane.  Biggest problem is 90% fall out over 1-6 months.  By plugging tear duct your tears stay in eye longer and artificial tears the same.  Probably worth a try.

[GrandKK]

Thank you. Dr. Hagan. I'm confused as to "until drop anesthesia in the eye exam lane"?