er... depends on what you refer to. cataract is an affliction of the lens. with increasing age the lens tends to get more opaque, though electromagnetic irradiation, steroids or diabetes (to mention a few) may speed up the process. standard procedure is to liquefy the opaque lens with an ultrasound probe, suck it up and replace it with an artifical lens, made of acrylic glass (or silicone). now glaucoma surgery is something entirely different; there are several procedures, some involving lasers. the problem with glaucoma is elevated intraocular pressure, or rather intraocular pressure that has reached the point where it is too high for the individual optic nerve to be supplied with enough blood (it's a matter of balance). thus, fibers of the optic nerve get "malnourished" and eventually die off. this results in loss of the visual field, and in the end in blindness. since no strategies to get the optic nerve to regenerate have so far been overly successful, there is basically just one thing to do: lower intraocular pressure to a point where it will be low enough to allow sufficient blood to reach the optic nerve. this can be done with medication, or surgically.
in surgery there are two options; enhance outflow of the aqueous humour to lower pressure, or decrease aqueous production. the former is done e.g. by widening schlemm's canal or by creating a fistula, an artificial outflow, usually through the sclera under the conjunctiva. the latter is done by destroying (cryo- or lasercoagulation) part of the ciliary body, the part of the eye where the aqueous is produced. this is of course just a quick overview... the cornea is only replaced when it has been damaged beyond repair- or when it is opaque while the eye remains functional.
there is more to myopia than just anomalous refraction. refractive surgery just does away with glasses/contacts. the myopic globe is elongated (just as the hyperopic globe is sort of "squashed"), so to speak, while the refractive properties of cornea, lens and vitreous remain essentially the same. this results in the focus point of the picture being formed in front of the retina, instead of on it. glasses or contact lenses just move the focus point back on the retina. in refractive surgery the properties of the cornea are changed to the same effect. but... refractive anomalies are just the most obvious signs of a myopic or hyperopic globe. as the myopic globe is longr than usual, the retina tends to be "stretched more thinly", as there is more strain on the retina in myopic eyes, there tend to be more degenerative areas which might form holes or even lead to retinal detachments. refractive surgery of the cornea doesn't fix that. also, hyperopic eyes are rather "shorter" than normal eyes, meaning that especially the anterior chamber and the chamber angle are more flat. this may constitute a predesposition for angle closure glaucoma. this also isn't fixed by refractive surgery, though it is usually improved through cataract surgery (but that's an entirely different subject). also the thinning out of the cornea which takes place during photorefractive surgery leads to erroneously low measurements of intraocular pressure, usualy by 3-4 Torr. this is due to the fact that all measurement of intraocular pressure is usually just registering how the cornea is deformed by a certain external pressure. if the cornea is thinner, the same pressure will allow further deformation and thus result in a lower registered IOP (though to be fair most ophthalmologists will measure corneal thickness and compensate accordingly).
quite so. refractive surgery is basically cosmetic surgery. the eye itself stays myopic or hyperopic (ok, it's different with astigmatism) with all the associated risks (e.g. angle closure glaucoma, retinal detachment). the only difference is that the refraction of the cornea has been adjusted (usually by thinning it) to fit the "length" of the globe... still, I'm not quite sure if there is that much of a benefit in refractive surgery for biathlets: especially 3-6 months after LASIK the ocular surface tends to be dryer than usual, which may cause irritation, a foreign body sensation, abnormal sensitivity to light and an increased need to blink. so the athlete in question may experience difficulties aiming. then of course this might even encourage him to aim faster and improve his time at the range...
"You English and your sense of humour. During your brief stay I look forward to learning more of your wit, your punning and your amusing jokes about ze breaking of ze wind. How lucky you English are to find ze toilet so amusing. For us, it is a mundane and functional item. For you, ze basis of an entire culture."
- Baron von Richthofen to Capt. E. Blackadder (Blackadder goes Forth, "Private Plane")
definitely. sure, the substance may be well-known but application as a therapeutic will require new processes of manufacture, new standards of purity, &c. also depending on the mode of administration (peroral, intravenous or maybe even intrathecal) different varieties of the parent substance might have to be developed... and that is just before the "me-too drugs" will appear.
That does of course make quite a difference. Thanks for clearing this up.There are after all some scientists out there who like to bypass peer reviews and publish their "breakthroughs" by leaking them to conventional media, which are generally less critical of scientists' claims. No offense was intended to your fathers or his colleagues' work. that said, I am excited to see what will become of this. as I understand the idea has been around for more than 12 years and it will be interesting to see what large scale clinical trials will reveal.
...before publishing their data in a peer-reviewed scientific journal? At least on pubmed.gov no article on this clinical trial or even a proposal for a clinical trial could be found. I wouldn't quite call it "fishy", but a little overly eager to go public. So maybe somebody was in a hurry to stake out his claim. A drug that could halt the progress of or prevent, or even delay the onset of Alzheimer's would be worth quite a large sum. there is a number of papers on the principle of action of this drug in a number of prestigious journals, e.g. "Selective inhibition of Alzheimer disease-like tau aggregation by phenothiazines.", by Wischick CM et al. (PNAS 1996). Apparently the drug is based on dyes like methylene blue which are quite common around most medical or biological labs... so one wonders how they will or have changed the basic substance to make it patentable (and a potential cash cow).
...with just two tiny drawbacks:
A) we don't have any jet-powered rocket pants, and
B) there's no such thing as jet-powered rocket pants outside the fictional serial "Robbie Rocketpants".
pubmed search on "Herberman RB" shows steady publication activity until dec 2006, mainly on immunological aspects of malignant tumors, not a single article on electromagnetic radiation, or anything even closely related. after that there is just a single article in a peer-reviewed journal. for the director of a semi-prominent institute on cancer research this lack of publication activity seems somewhat unusual.
Slashdot Mirror
er... depends on what you refer to. cataract is an affliction of the lens. with increasing age the lens tends to get more opaque, though electromagnetic irradiation, steroids or diabetes (to mention a few) may speed up the process. standard procedure is to liquefy the opaque lens with an ultrasound probe, suck it up and replace it with an artifical lens, made of acrylic glass (or silicone). now glaucoma surgery is something entirely different; there are several procedures, some involving lasers. the problem with glaucoma is elevated intraocular pressure, or rather intraocular pressure that has reached the point where it is too high for the individual optic nerve to be supplied with enough blood (it's a matter of balance). thus, fibers of the optic nerve get "malnourished" and eventually die off. this results in loss of the visual field, and in the end in blindness. since no strategies to get the optic nerve to regenerate have so far been overly successful, there is basically just one thing to do: lower intraocular pressure to a point where it will be low enough to allow sufficient blood to reach the optic nerve. this can be done with medication, or surgically. in surgery there are two options; enhance outflow of the aqueous humour to lower pressure, or decrease aqueous production. the former is done e.g. by widening schlemm's canal or by creating a fistula, an artificial outflow, usually through the sclera under the conjunctiva. the latter is done by destroying (cryo- or lasercoagulation) part of the ciliary body, the part of the eye where the aqueous is produced. this is of course just a quick overview... the cornea is only replaced when it has been damaged beyond repair- or when it is opaque while the eye remains functional.
there is more to myopia than just anomalous refraction. refractive surgery just does away with glasses/contacts. the myopic globe is elongated (just as the hyperopic globe is sort of "squashed"), so to speak, while the refractive properties of cornea, lens and vitreous remain essentially the same. this results in the focus point of the picture being formed in front of the retina, instead of on it. glasses or contact lenses just move the focus point back on the retina. in refractive surgery the properties of the cornea are changed to the same effect. but... refractive anomalies are just the most obvious signs of a myopic or hyperopic globe. as the myopic globe is longr than usual, the retina tends to be "stretched more thinly", as there is more strain on the retina in myopic eyes, there tend to be more degenerative areas which might form holes or even lead to retinal detachments. refractive surgery of the cornea doesn't fix that. also, hyperopic eyes are rather "shorter" than normal eyes, meaning that especially the anterior chamber and the chamber angle are more flat. this may constitute a predesposition for angle closure glaucoma. this also isn't fixed by refractive surgery, though it is usually improved through cataract surgery (but that's an entirely different subject). also the thinning out of the cornea which takes place during photorefractive surgery leads to erroneously low measurements of intraocular pressure, usualy by 3-4 Torr. this is due to the fact that all measurement of intraocular pressure is usually just registering how the cornea is deformed by a certain external pressure. if the cornea is thinner, the same pressure will allow further deformation and thus result in a lower registered IOP (though to be fair most ophthalmologists will measure corneal thickness and compensate accordingly).
quite so. refractive surgery is basically cosmetic surgery. the eye itself stays myopic or hyperopic (ok, it's different with astigmatism) with all the associated risks (e.g. angle closure glaucoma, retinal detachment). the only difference is that the refraction of the cornea has been adjusted (usually by thinning it) to fit the "length" of the globe... still, I'm not quite sure if there is that much of a benefit in refractive surgery for biathlets: especially 3-6 months after LASIK the ocular surface tends to be dryer than usual, which may cause irritation, a foreign body sensation, abnormal sensitivity to light and an increased need to blink. so the athlete in question may experience difficulties aiming. then of course this might even encourage him to aim faster and improve his time at the range...
"We did *NOT* start it!"
"You English and your sense of humour. During your brief stay I look forward to learning more of your wit, your punning and your amusing jokes about ze breaking of ze wind. How lucky you English are to find ze toilet so amusing. For us, it is a mundane and functional item. For you, ze basis of an entire culture." - Baron von Richthofen to Capt. E. Blackadder (Blackadder goes Forth, "Private Plane")
...HAL. "I'm sorry Dave, I'm afraid I can't do that." ... not until you've cleaned up under the seat.
definitely. sure, the substance may be well-known but application as a therapeutic will require new processes of manufacture, new standards of purity, &c. also depending on the mode of administration (peroral, intravenous or maybe even intrathecal) different varieties of the parent substance might have to be developed... and that is just before the "me-too drugs" will appear.
That does of course make quite a difference. Thanks for clearing this up.There are after all some scientists out there who like to bypass peer reviews and publish their "breakthroughs" by leaking them to conventional media, which are generally less critical of scientists' claims. No offense was intended to your fathers or his colleagues' work. that said, I am excited to see what will become of this. as I understand the idea has been around for more than 12 years and it will be interesting to see what large scale clinical trials will reveal.
...before publishing their data in a peer-reviewed scientific journal? At least on pubmed.gov no article on this clinical trial or even a proposal for a clinical trial could be found. I wouldn't quite call it "fishy", but a little overly eager to go public. So maybe somebody was in a hurry to stake out his claim. A drug that could halt the progress of or prevent, or even delay the onset of Alzheimer's would be worth quite a large sum. there is a number of papers on the principle of action of this drug in a number of prestigious journals, e.g. "Selective inhibition of Alzheimer disease-like tau aggregation by phenothiazines.", by Wischick CM et al. (PNAS 1996). Apparently the drug is based on dyes like methylene blue which are quite common around most medical or biological labs... so one wonders how they will or have changed the basic substance to make it patentable (and a potential cash cow).
...with just two tiny drawbacks: A) we don't have any jet-powered rocket pants, and B) there's no such thing as jet-powered rocket pants outside the fictional serial "Robbie Rocketpants".
pubmed search on "Herberman RB" shows steady publication activity until dec 2006, mainly on immunological aspects of malignant tumors, not a single article on electromagnetic radiation, or anything even closely related. after that there is just a single article in a peer-reviewed journal. for the director of a semi-prominent institute on cancer research this lack of publication activity seems somewhat unusual.