The HD is more sensitive to residual astigmatism and refractive error. The AT50 is more forgiving and micromonovision works better. You can target the non-dominant eye slightly myopic and improve near vision with a slight decrease in distance vision. A patient using both eyes will see both distance and near well. Micromonovison does not work with the HD and you have to target both eyes to plano (zero) or +.25. The AT50 targets are -0.25 for the dominant eye and -.50 to -.75 for the nondominant eye.
HD near vision improve with time and does not degrade.
You can see fairly well with upto 1.00 of residual astigmatism with the AT50, but with the HD astigmatism has to be .50 or less.
I use atropine for all my Crystalens patients and have them use readers for two weeks. If the pupil reacts on day 5, I put in one more drop of atropine. If you were a ble to read before cataract surgery without reader, you were nearsighted. To see well at distance the Crystalens has to correct the near sightedness. Therefore is you are to see well at distance without glasses, you will nead reader to see near.
The yagging of the anterior capsule for residual hyperopia is not well understood by most Crystalens surgeons. Also, most surgeon do not know how to predicatably control astigmatism. Most surgeons use a fixed depth LRI blade. We learned from the RK days that you need to make a cut in the cornea to 90% depth to get a good effect. Also, it is difficult to measure the thickness of the peripheral cornea with standard pachymeters and most surgeons do not have a micrometer adjusted LRI blade-very expensive to do depth adjusted LRI. Google Nichamin NAPA nomogram.
Thank you very much for your reply.
After carefully reading it, it appears that Crystalens HD's predictability and post operative remedy (if necessary) may be best managed by a surgeon who has ample experience in using Crystalens and who is well-versed in capsule yagging and variable-depth LRI. Careful and frequent follow-ups are also important.
As I live in Hong Kong where Crystalens is new, I have 2 options:
1) Go to Singapore where Crystalens experience is higher but can still be improved.
2) Go to the US where Crystalens Center of Excellence Award doctors can be found.
Still I cannot afford to stay long in either place for frequent follow-ups.
Is there anything that can be done to shorten my stay? To warrant good if not best results, what is the minimum time to stay?
Many Thanks in advance.
You mentioned "...you will need reader to see near." Do you mean just for the adjusting period of 2 weeks after surgery. My understanding is, over time, Crystalens HD normally achieves workable uncorrected near vision beyond 40 cm.
I would say if you really want a Crystalens then a Crystalens Center of Excelence is a good start, However...This title is granted by the makers of the Crystalens and I don't know what their exact requirements are for granting this title. I believe they need only to implant 100 Crystalens sucsessfully to obtain this title but I'm not 100% sure. I don't know how they measure a sucessful implantation but I do know my doctor chalked mine up as a sucsess being 20/20 even though I cannot read a license plate at six feet. That with many side effects included at no additional charge. Yes, he held the "Center of Exelence" title. If you do decide to go through with the Crystalens, I would sugest that you go with an Opthamologist who takes his time with your pre op evaluation and measurements. This is a very good indicator of how much time he/she will dedicate to you post op should a problem arise and may avoid a problem in the first place. Good Luck!
Thank you for your comment and suggestion. I wonder what had happened to you and what has been done to correct or improve your situation.
From Dr.O's initial response am I correct to assume that the Crystalens HD is not the best choice for one, such as myself, with a fair amount of astigmatism ? Also, I should seek a surgeon skilled and with equipment to perform variable depth LRI?
Dr. Dell is in Austin, about 4 hours south of Dallas--how would I find a qualified surgeon with this micrometer adjustable blade locally?
Thank you once again for your skilled guidance; perhaps I should travel to Los Angeles!
Probably not worth the trip to L.A. I have been to many Ophthalmologists in the L.A. area and I wouldn't presume they are any better than those is Austin. I find these "Beverly Hills" based practices don't spend the necessary amount of time on pre or post op with their patients.