> 27 years ago... in Spain...

> Which of the top LASIK surgeons you have yet to name -yet you claim to
> have learned from - agrees in the slightest degree with this?
> Does it ever bother you that you are misleading people and scaring
> them needlessly? Is that your intention?
> It fringhtens me to think that even one person would decide not to
> have LASIK based upon your garbage. There are people that LASIK is
> not the best solution for. You just seem to think that is everybody.
> Please tell us who you think LASIK is suitable for.
> On 2 Mar 2004 21:35:41 -0800, sandy[at]savvysneaks.com (Sandy) wrote:
> > Neural basis of sensation in intact and injured corneas
> > This paper is dedicated to the memory of David Maurice. As in so many
> > other aspects of corneal research, David realized in the early 1970s
> > the need of new methods and approaches to fully understand the
> > mechanisms of corneal sensitivity, and led one of the first attempts
> > to record electrical activity from corneal nerve fibres `in vitro'
> > ([Mark and Maurice, 1977]) as well as to study human corneal sensation
> > using different modalities of stimuli ( [Beuerman et al., 1977]).
> > Twenty-five years later, similar techniques are being used routinely
> > to extend our knowledge of the functional properties and roles of
> > corneal sensory receptors in normal and injured corneas with the aim
> > of understanding corneal pain, one of the many scientific problems
> > that excited David's insatiable curiosity.
> > > Carlos Belmonte, , M. Carmen Acosta and Juana Gallar
> > > Instituto de Neurociencias de Alicante, Universidad Miguel
> > Hernández?CSIC, Apdo correos 18, 03550, San Juan de Alicante, Spain
> > > Received 18 September 2003; accepted 25 September 2003. ; Available
> > online 19 December 2003.
> > > > > > Abstract
> > A renewed interest in the characteristics and neural basis of corneal
> > and conjunctival sensations is developing in recent years due to the
> > high incidence of discomfort and altered sensitivity of the cornea
> > following refractive surgery, use of contact lenses and dry eyes.
> > Corneal nerves are functionally heterogeneous: about 20% respond
> > exclusively to noxious mechanical forces (mechano-nociceptors); 70%
> > are additionally excited by extreme temperatures, exogenous irritant
> > chemicals and endogenous inflammatory mediators (polymodal
> > nociceptors), and 10% are cold-sensitive and increase their discharge
> > with moderate cooling of the cornea (cold receptors). Each of these
> > types of sensory fibres contributes distinctly to corneal sensations.
> > Mechano-nociceptors mediate, sharp acute pain produced by touching of
> > the cornea. Polymodal nociceptors elicit the sustained irritation and
> > pain that accompany corneal wounding; cold receptors evoke cooling
> > sensations. Depending on the relative activation by the stimulus of
> > each subpopulation of corneal sensory fibres, different subqualities
> > of irritation and pain sensations are evoked. Corneal sensations can
> > be explored experimentally in humans with a gas esthesiometer that
> > applies controlled mechanical, chemical and thermal stimuli to the
> > corneal surface. When the cornea is wounded, corneal nerves are
> > excited and eventually severed in a variable degree and local
> > inflammation is produced. Activated corneal nerves release
> > neuropeptides (SP, CGRP) that contribute to the inflammatory reaction
> > (neurogenic inflammation). They also become sensitized by local
> > inflammatory mediators, such as prostaglandins or bradykinin and thus
> > exhibit spontaneous activity, lowered threshold and enhanced responses
> > to new stimuli. This leads to spontaneous pain and hyperalgesia.
> > Nerves destroyed by injury soon start to regenerate and form
> > microneuromas that exhibit abnormal responsiveness and spontaneous
> > discharges, due to an altered expression of ion channel proteins in
> > the soma and in regenerating nerve terminals. Presumably, this altered
> > excitability is the origin of the lowered sensitivity and the
> > spontaneous pain, dry eye sensations and other disaesthesias reported
> > in patients following refractive surgery.
> > > Author Keywords: pain; corneal nerves; ocular surface; sensitivity;
> > conjunctiva; dry eye; corneal inflammation; photorefractive
> > keratectomy; laser-assisted in situ keratomileusis; nerve injury

> Neural basis of sensation in intact and injured corneas
> This paper is dedicated to the memory of David Maurice. As in so many
> other aspects of corneal research, David realized in the early 1970s
> the need of new methods and approaches to fully understand the
> mechanisms of corneal sensitivity, and led one of the first attempts
> to record electrical activity from corneal nerve fibres `in vitro'
> ([Mark and Maurice, 1977]) as well as to study human corneal sensation
> using different modalities of stimuli ( [Beuerman et al., 1977]).
> Twenty-five years later, similar techniques are being used routinely
> to extend our knowledge of the functional properties and roles of
> corneal sensory receptors in normal and injured corneas with the aim
> of understanding corneal pain, one of the many scientific problems
> that excited David's insatiable curiosity.
> Carlos Belmonte, , M. Carmen Acosta and Juana Gallar
> Instituto de Neurociencias de Alicante, Universidad Miguel
> Hernández–CSIC, Apdo correos 18, 03550, San Juan de Alicante, Spain
> Received 18 September 2003; accepted 25 September 2003. ; Available
> online 19 December 2003.
> Abstract
> A renewed interest in the characteristics and neural basis of corneal
> and conjunctival sensations is developing in recent years due to the
> high incidence of discomfort and altered sensitivity of the cornea
> following refractive surgery, use of contact lenses and dry eyes.
> Corneal nerves are functionally heterogeneous: about 20% respond
> exclusively to noxious mechanical forces (mechano-nociceptors); 70%
> are additionally excited by extreme temperatures, exogenous irritant
> chemicals and endogenous inflammatory mediators (polymodal
> nociceptors), and 10% are cold-sensitive and increase their discharge
> with moderate cooling of the cornea (cold receptors). Each of these
> types of sensory fibres contributes distinctly to corneal sensations.
> Mechano-nociceptors mediate, sharp acute pain produced by touching of
> the cornea. Polymodal nociceptors elicit the sustained irritation and
> pain that accompany corneal wounding; cold receptors evoke cooling
> sensations. Depending on the relative activation by the stimulus of
> each subpopulation of corneal sensory fibres, different subqualities
> of irritation and pain sensations are evoked. Corneal sensations can
> be explored experimentally in humans with a gas esthesiometer that
> applies controlled mechanical, chemical and thermal stimuli to the
> corneal surface. When the cornea is wounded, corneal nerves are
> excited and eventually severed in a variable degree and local
> inflammation is produced. Activated corneal nerves release
> neuropeptides (SP, CGRP) that contribute to the inflammatory reaction
> (neurogenic inflammation). They also become sensitized by local
> inflammatory mediators, such as prostaglandins or bradykinin and thus
> exhibit spontaneous activity, lowered threshold and enhanced responses
> to new stimuli. This leads to spontaneous pain and hyperalgesia.
> Nerves destroyed by injury soon start to regenerate and form
> microneuromas that exhibit abnormal responsiveness and spontaneous
> discharges, due to an altered expression of ion channel proteins in
> the soma and in regenerating nerve terminals. Presumably, this altered
> excitability is the origin of the lowered sensitivity and the
> spontaneous pain, dry eye sensations and other disaesthesias reported
> in patients following refractive surgery.
> Author Keywords: pain; corneal nerves; ocular surface; sensitivity;
> conjunctiva; dry eye; corneal inflammation; photorefractive
> keratectomy; laser-assisted in situ keratomileusis; nerve injury

> Neural basis of sensation in intact and injured corneas
> This paper is dedicated to the memory of David Maurice. As in so many
> other aspects of corneal research, David realized in the early 1970s
> the need of new methods and approaches to fully understand the
> mechanisms of corneal sensitivity, and led one of the first attempts
> to record electrical activity from corneal nerve fibres `in vitro'
> ([Mark and Maurice, 1977]) as well as to study human corneal sensation
> using different modalities of stimuli ( [Beuerman et al., 1977]).
> Twenty-five years later, similar techniques are being used routinely
> to extend our knowledge of the functional properties and roles of
> corneal sensory receptors in normal and injured corneas with the aim
> of understanding corneal pain, one of the many scientific problems
> that excited David's insatiable curiosity.
> Carlos Belmonte, , M. Carmen Acosta and Juana Gallar
> Instituto de Neurociencias de Alicante, Universidad Miguel
> Hernández–CSIC, Apdo correos 18, 03550, San Juan de Alicante, Spain
> Received 18 September 2003; accepted 25 September 2003. ; Available
> online 19 December 2003.
> Abstract
> A renewed interest in the characteristics and neural basis of corneal
> and conjunctival sensations is developing in recent years due to the
> high incidence of discomfort and altered sensitivity of the cornea
> following refractive surgery, use of contact lenses and dry eyes.
> Corneal nerves are functionally heterogeneous: about 20% respond
> exclusively to noxious mechanical forces (mechano-nociceptors); 70%
> are additionally excited by extreme temperatures, exogenous irritant
> chemicals and endogenous inflammatory mediators (polymodal
> nociceptors), and 10% are cold-sensitive and increase their discharge
> with moderate cooling of the cornea (cold receptors). Each of these
> types of sensory fibres contributes distinctly to corneal sensations.
> Mechano-nociceptors mediate, sharp acute pain produced by touching of
> the cornea. Polymodal nociceptors elicit the sustained irritation and
> pain that accompany corneal wounding; cold receptors evoke cooling
> sensations. Depending on the relative activation by the stimulus of
> each subpopulation of corneal sensory fibres, different subqualities
> of irritation and pain sensations are evoked. Corneal sensations can
> be explored experimentally in humans with a gas esthesiometer that
> applies controlled mechanical, chemical and thermal stimuli to the
> corneal surface. When the cornea is wounded, corneal nerves are
> excited and eventually severed in a variable degree and local
> inflammation is produced. Activated corneal nerves release
> neuropeptides (SP, CGRP) that contribute to the inflammatory reaction
> (neurogenic inflammation). They also become sensitized by local
> inflammatory mediators, such as prostaglandins or bradykinin and thus
> exhibit spontaneous activity, lowered threshold and enhanced responses
> to new stimuli. This leads to spontaneous pain and hyperalgesia.
> Nerves destroyed by injury soon start to regenerate and form
> microneuromas that exhibit abnormal responsiveness and spontaneous
> discharges, due to an altered expression of ion channel proteins in
> the soma and in regenerating nerve terminals. Presumably, this altered
> excitability is the origin of the lowered sensitivity and the
> spontaneous pain, dry eye sensations and other disaesthesias reported
> in patients following refractive surgery.
> Author Keywords: pain; corneal nerves; ocular surface; sensitivity;
> conjunctiva; dry eye; corneal inflammation; photorefractive
> keratectomy; laser-assisted in situ keratomileusis; nerve injury