Posts from June, 2010
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Jun0Intrastromal Corneal Ring Segments-Part 6
Introduction: The Intacs intrastromal ring segments have been demonstrated to cause corneal flattening in keratoconus.[2, 5, 6, 22, 35, 38, 39]. The change in spherical equivalent and keratometry have been significant and about 80% of eyes achieve an improvement in uncorrected and best corrected visual acuity[6, 20]. Collagen cross linking has been shown to slow [...]
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Jun0Intrastromal Corneal Ring Segments: Part 5
Complications: Complications with use of Intacs can be divided into intraoperative and post-operative. The main intraoperative complication that occurred was that the Intacs could not be inserted in 8% of some series [23]. Intraoperative perforation was also reported[35]. The majority of series reported no intraoperative complications[5, 6, 20, 23]. The rate of post-operative complications depended [...]
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Jun0Intrastromal Corneal Ring Segments-Part 4
Refractive Cylinder: All other studies that bothered to report the change in refractive cylinder have demonstrated a reduction. The mean reduction in keratoconic has been between 1.3 and 2.7 dioptres. Few studies took in to account wither vector analysis or keratometric astigmatism. Spherical Equivalent: All other studies demonstrated a reduction in post-operative spherical equivalent. The [...]
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Jun0Intrastromal Corneal Ring Segments: Part 3
This body of evidence is relatively sparse and according to the NH & MRC classification for dimensions of evidence (NH & MRC 2000) presents only a grade 4/4 evidence level. The maximum total number of keratoconic eyes treated, that have been recorded in published series less than 1000, although this number is somewhat uncertain as [...]
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Jun0Intrastromal Corneal Ring Segments: Part 2
The Intacs are made from PMMA (Polymethyl Methacrylate) and come in segments between 0.25mm and 0.45mm with an arc length of 150 microns. The surgical procedure can be performed utilising a surgical device which involves stromal separation of the corneal lamellar at a fixed depth or, more commonly these days, with the IntraLase femtosecond laser. [...]
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Jun0Intrastromal Corneal Ring Segments: Part 1
The Intrastromal Corneal Ring Segments (ICRS) are small semi-circular plastic segments which can be inserted into stromal channels in the mid-periphery of the cornea. The segments act as passive spacing elements and can shorten the arc length of the anterior corneal surface inducing flattening. ([1-3]. Whilst they were originally designed to treat low levels of [...]
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Jun1Intrastromal Corneal Ring Segments
Background and Literature Review The Intrastromal Corneal Ring Segments (ICRS) are small semi-circular plastic segments which can be inserted into stromal channels in the mid-periphery of the cornea. The segments act as passive spacing elements and can shorten the arc length of the anterior corneal surface inducing flattening. ([1-3]. Whilst they were originally designed to [...]
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Jun0Corneal Collagen Cross-Linking (also referred to as CXL)
Although current treatments for keratoconus, such as contact lenses and corneal ring implants, can improve vision, they do not treat the underlying cause, corneal weakness. As such they do not prevent the keratoconus from progressing. Corneal collagen cross-linking aims to address this problem.
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