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Medical Forum / General / Vision / May 2004Unusual astigmatism question
Most of a year after cateract removal and lens implant,my right eye needs: -1.0 -1.75 @ 10 deg. A thin line at 100 deg. focuses sharply with its best correction, but a thin line at 10 deg. is less sharp with its best correction. Corrected vision is good, but it is difficult to measure the correct Rx because of the above. Note that the surgery required intact removal of the lens, (Phaco. was not possible.), and some stitching on top of the eye. Stitches were never removed, though they may have dissolved. The Rx the day after surgery was: 0 -4.0 @10 deg. Is this a known condition? Clearly something more than correctable astigmatism? Thanks, Jack > Most of a year after cateract removal and lens implant,my right eye needs: > [quoted text clipped - 19 lines] > > Jack It seems the pros here do not have any clue for your uneasiness of vision. This is normal. These people are just ignorant of the truth about vision. If you are intelligent, you may find much information available on the Internet, simple things, that you can try and work out. > Most of a year after cateract removal and lens implant,my right eye needs: > [quoted text clipped - 19 lines] > > Jack Not sure exactly what you're talking about. What is your best corrected visual acuity (ie with glasses)? You state only that it's "good". Doesn't make sense to me that one meridian is sharper if you have the proper correction. frank > > Most of a year after cateract removal and lens implant,my right eye needs: > > [quoted text clipped - 27 lines] > > frank Vision is corrected to close to 20/20 in that right eye. Looking at perpendicular thin lines, for example newspaper column boxes turned slightly to my meridians 10 deg and 100 deg., the 100 deg. line focuses in a well-defined narrow range from my reading glasses. It is much harder to find just where the 10-deg-line focuses best. The same distance as the 100-deg-line seems as good a distance as any, so I guess the cyl correction is right. But it does not sharpen up in the narrow range like the 100-deg-line, and never gets as sharp as the 100-deg-line. Since the cateract surgery caused this astig. (stitches above) I'm guessing that it caused something a little more complicated and associated with the same cyl axis, something not correctable with lenses. I'm still happy with my new vision. It's much better than my left eye that has a cateract, not ready for surgery. Just wondering whether anyone has heard of this condition before. Thanks, Jack Brody The surgery you must have had was an extracapsular cataract extraction. This necessitates a large (about 160 degree) incision, which is closed with radial sutures. These sutures cause compression of the tissue within the loop of the suture, which causes shortening of the tissues in that meridian, which makes the radius of the eyeball smaller, casing a change in the curvature of the cornea. Assuming sutures along the superior part of the cormnea, this induces "with-the-rule" astigmatism, with the steeper curvature in the vertical meridian. If you need a -4D @10 deg, the steepest is at 80 deg, w(where 90 deg is at the 12 o'clock location). 4 diopt, 1 day after surgery is not uncommon. Typically, at about 6-7 weeks postop, the shape of the eye is measured with a keratometer, or a refraction is done, and a single suture is cut at the location of the steepest curvature. Wait 1 week, do all over again, as the axis of the astigmatism moves to the next tightest suture. Keep doing this every week until about 1 - 1.5 diopters remains. This then gradually melts away with time. If you reduce the curvature to zero, it will go the other way (against-the-rule astigmatism), which is more bothersome. I used to have to do this when I did extra-cap surgery, which I pretty much stopped doing in the early 1990's. Scleral tunnels have little astigmatism, and the clear cornea surgery I'm doing (since 1995) has even less. Neither of those techniques usually require sutures. This usually needs to be done by 3-6 months after surgery, before things have healed too far. While this is now a long time after, if therre are still tight sutures at 80 deg, cutting them may reduce the 1.75 diop. astigmatism somewhat, still. Sutures are usually 10-0 nylon, which, while they are very thin, do not dissolve, really. Yes, after many years they may deteriorate and loosen, but not at 1 year out. (PS: an small-incision extra-cap can be done through a 6 mm sutureless scleral tunnel if the nucleus is divided and removed in 2 or 3 pieces using special inexpensive manual instruments. This is what I do in the rare case where the nucleus is too hard to remove with phako, or if the phako machine should die in the middle of a case. I've done about 40 cases this way, mostly when I was transitioning from extra-caps to phako.) David Robins, MD Board certified Ophthalmologist Pediatric and strabismus subspecialty Member of AAPOS (American Academy of Pediatric Ophthalmology and Strabismus) On 5/24/04 2:26 PM, in article 2hf7khFbs29uU1@uni-berlin.de, ".Jack Brody" <spamdump@hotmail.com> wrote: > Most of a year after cateract removal and lens implant,my right eye needs: > [quoted text clipped - 19 lines] > > Jack To: David Robins, MD Thank you for your thorough answer. I not sure what "extracapsular cataract extraction" is, but it sounds like more surgery than I had. The MD talked about taking out the cateract whole. Phaco did not work. He did not remove the capsule. I follow what you said about the stitching leading to the astig., but don't you mean 10 deg and 100 deg? (rather than 80 deg) Since the cyl went down from -4 @ 10 deg to -2 @ 10 deg over the first few weeks, I thought the stitches dissolved at that time. You think they just loosened. They were never removed nor even cut. You think they should still be cut for less astig. The cyl has been fairly stable for the 8 months after the first month, but the needed sph went more neg by more than -1.00 diop. I sure would like the Rx to stablize. The left eye faces surgery now, with its Rx sph zooming negative and cyl growing rapidly too. I now see my R. optimum cyl. varying between -1.75 and 2.00 over hours. Not a problem. But is this kind of variation expected, given my surgery? What about the asymmetry in quality of focus at the two meridians? I hope you have patience for all these questions. Thank you again, Jacl > The surgery you must have had was an extracapsular cataract extraction. This > necessitates a large (about 160 degree) incision, which is closed with [quoted text clipped - 67 lines] > > > > Jack To: Dr. Robins I found my surgery bill. It says I had: "cataract surgery w/iol, 1 stage (66984-RT)" Is that not an extracapsular cataract extraction? And I'm an E.E. too. Jack > To: David Robins, MD > [quoted text clipped - 113 lines] > > > > > > Jack |
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