Re: radial keratotomy and Excimer Lasers

   Two minor corrections to your message concerning RK.

      1)  The Excimer Laser *Corneal Sculpting* does not rely on scarring
caused by radially aligned cuts to achieve the desired effect.  Rather, it
ablates corneal stroma to directly alter the curvature of the anterior
cornea using circumfrencial (sp?) "cuts".  Early studies have shown that
like RK, there tends to be a reversion in the direction of the origional
refractive error.  Additionally, Corneal Sculpting is being viewed by
opthalmologists with some healthy reservations after the disappointments
they had with RK.

     2)  Radial Keratotomy is *not* without risk.  While the frequency of
serious adverse reactions is low, a couple of eyes have had to be enucleated
while several more have had to undergo full thickness (penetrating) kerato-
plasty (corneal transplant).  Furthermore, RK is now viewed by most as too
unpredictable for cosmetic use.  From what I hear, most RK’s done today are
done on very myopic eyes in order to permit the patient to wear thinner
glasses (as opposed to the proverbial "coke bottle bottoms").   At it’s peak
of popularity, about 20% of the nations ophthalmologists were doing RK, but
that has dropped to 7% today (according to an ophthalmologist friend of mine).
Many of those ophthalmologists who still do RK will argue that the poor
results reported in the PERK study are due to the relative lack of skills of
the operators whereas RK is very safe, effective, and predictable when
performed by a surgeon who is truely qualified to do the procedure.  Indeed,
the overall success of any surgical procedure will be influenced by the skill
of the operator.  Therefore, in the right hands (so to speak) RK can be said
to be relatively safe — but in the wrong hands, who knows? (not me!)
Personally, I wouldn’t let anybody cut my eyes just to avoid wearing glasses
or contact lenses.

Steve

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5 Responses to “Re: radial keratotomy and Excimer Lasers”

  1. admin says:

    In a message of <18 Apr 90 00:43:56>, Stephen Risik Of 100/514 (1:100/514)
    writes:

     SR>Many of those ophthalmologists who still do RK will argue that the poor
     SR>results reported in the PERK study are due to the relative lack of
     SR>skills of
     SR>the operators whereas RK is very safe, effective, and predictable when
     SR>performed by a surgeon who is truely qualified to do the procedure.  
     SR>Indeed,
     SR>the overall success of any surgical procedure will be influenced by the
     SR>skill
     SR>of the operator.  Therefore, in the right hands (so to speak) RK can be
     SR>said
     SR>to be relatively safe — but in the wrong hands, who knows? (not me!)
     SR>Personally, I wouldn’t let anybody cut my eyes just to avoid wearing
     SR>glasses
     SR>or contact lenses.

    Steve – the most serious problem with the PERK study was their insistence on
    using only 3 optical zones and not tailoring the surgery for the patient. They
    completely ignored Slava and my previous work and reccomendations and did
    NOTHING to predict the outcome using known factors.

    Leo Bores, M.D.

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  2. admin says:

    In article <17084.26324…@stjhmc.fidonet.org> Stephen.Risik.Of.100/…@f514.n100.z1.fidonet.org (Stephen Risik Of 100/514) writes:

    }of the operator.  Therefore, in the right hands (so to speak) RK can be said
    }to be relatively safe — but in the wrong hands, who knows? (not me!)
    }Personally, I wouldn’t let anybody cut my eyes just to avoid wearing glasses
    }or contact lenses.

    I would gladly let someone cut my eyes to avoid wearing glasses or
    contacts, but I’d like to make sure they are skilled.  Is number of
    RK operations performed a useable (if quite crude) metric?  Any
    other ways to determine whether or not your selected surgeon has what
    it takes to do a quality RK?

    Curtis Jackson @ Adobe Systems in Mountain View, CA  (415-962-4905)
    Internet: jack…@adobe.com uucp: …!{apple|decwrl|sun}!adobe!jackson

  3. admin says:

    This question is about the use of lasers in RK, or other eye surgery.
    There are some drugs, such as the psorleans, beta-carotine, phenobarb, and many
    many more that increase cause photosensitivity. Also there are heme
    derrivitives, and such (as in hemataphin) that arused BECAUSE they
    cause photosensitivity. Are these ever a concern, or are they used?
    (in eye surgery) Also, are YAG lasers used, tunable dye, or is CO2 the
    preference? Also as far as beta-carotine being a photic sensitiser,
    and I mean no racial slurrs here, but do different races require a specific
    adjustment for a ler proceedure? How about MS? Also, how about
    Retinitis Pigmentosa? Does Leber’s Hereditarty optic Neuropathy casue a
    probleN)?

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  4. admin says:

    In an article of <26 Apr 90 02:01:25 GMT>, jack…@adobe.COM (Curtis Jackson)
    writes:

     CJ>I would gladly let someone cut my eyes to avoid wearing glasses or
     CJ>contacts, but I’d like to make sure they are skilled.  Is number of
     CJ>RK operations performed a useable (if quite crude) metric?  Any
     CJ>other ways to determine whether or not your selected surgeon has what
     CJ>it takes to do a quality RK?

    I would go more on the length of time he/she has been performing the surgery
    and secondarily the numbers (some guys put people through their clinics like
    pork through a goose with VERY little follow-up – they’re more likely to
    screw-up than someone doing fewer but doing a careful follow-up). Ask to speak
    to patients who have had the surgery at their hands – if they are uncooperative
    – go elsewhere (make sure that ONE of the patients spoken too has less than a
    perfect result.

    Leo Bores, M.D.

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  5. admin says:

    In a message of <25 Apr 90  16:17:07>, Robin Salmansohn (1:273/701) writes:

     RS>This question is about the use of lasers in RK, or other eye surgery.
     RS>There are some drugs, such as the psorleans, beta-carotine, phenobarb,
     RS>and many many more that increase cause photosensitivity. Also there are
     RS>heme
     RS>derrivitives, and such (as in hemataphin) that arused BECAUSE they
     RS>cause photosensitivity. Are these ever a concern, or are they used?
     RS>(in eye surgery) Also, are YAG lasers used, tunable dye, or is CO2 the
     RS>preference? Also as far as beta-carotine being a photic sensitiser,
     RS>and I mean no racial slurrs here, but do different races require a
     RS>specific adjustment for a ler proceedure? How about MS? Also, how about
     RS>Retinitis Pigmentosa? Does Leber’s Hereditarty optic Neuropathy casue a
     RS>probleN)?

    The use of photo-sensitizing chemicals associated with corneal photoablation is
    the subject of a patent acquired recently by an east coast ophthalmologist. As
    to the chemicals described above – I don’t believe that enough work has been
    done under those circumstances to be sure.

    Tunable dye lasers are being investigated as are frequency doubled YAGs. In my
    opinion, the doubled YAG shows the most promise. The energy is delivered much
    more rapidly avoiding the problem of movement for one thing.

    I would suspect that there will be some racial considerations – there is in
    corneal transplantation but exactly how race will play a part is not known yet.

    I would not be concerned about the use of laser in cases of MS, RP, or Lebers
    all of these are affecting parts of the neuroepithelium which does not include
    corneal nerves.

    Leo Bores, M.D.

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