A reasonably large study (by the standards of Keratoconus) into post procedure C3R outcomes at +12 months has concluded. The link is here:
http://www.ncbi.nlm.nih.gov/pubmed/21420594
... but I've a hunch you have to register so don't be surprised if you get nagged for your name or email address or what-not. In any case, I've cut 'n pasted the Abstract below, you don't get given any more for free than this:
Corneal thickness changes after corneal collagen crosslinking for keratoconus and corneal ectasia: One-year results.
Greenstein SA, Shah VP, Fry KL, Hersh PS.
Source
From the Cornea and Laser Eye Institute-Hersh Vision Group (Greenstein, Shah, Fry, Hersh), CLEI Center for Keratoconus, Teaneck, and the Department of Ophthalmology (Shah, Hersh), UMDNJ-New Jersey Medical School, Newark, New Jersey, USA.
Abstract
PURPOSE: To determine the changes in corneal thickness over time after corneal collagen crosslinking (CXL) for keratoconus and corneal ectasia.
SETTING: Cornea and refractive surgery subspecialty practice.
DESIGN: Prospective randomized controlled clinical trial.
METHODS: Corneal thickness at the apex, thinnest point, and pupil center were measured using Scheimpflug imaging (Pentacam) at baseline and 1, 3, 6, and 12 months after CXL. The treatment group was compared with both a sham-procedure control group and a fellow-eye control group. Associations with clinical outcomes (uncorrected and corrected distance visual acuities and maximum keratometry) were analyzed.
RESULTS: The study comprised 82 eyes, 54 with keratoconus and 28 with ectasia after laser in situ keratomileusis. The mean preoperative thinnest pachymetry was 440.7 μm ± 52.9 (SD). After CXL, the cornea thinned at 1 month (mean change -23.8 ± 28.7 μm; P<.001) and from 1 to 3 months (mean change -7.2 ± 20.1 μm, P=.002), followed by a recovery of the corneal thickness between 3 months and 6 months (mean +20.5 ± 20.4 μm; P<.001). At 1 year, apex and pupil-center thicknesses returned to baseline (P=.11 and P=.06, respectively); however, the thinnest pachymetry remained slightly decreased from baseline to 12 months (mean change -6.6 ± 22.4 μm; P=.01). The recovery of corneal thickness was more rapid in ectasia than in keratoconus. There was no association between the degree of corneal thinning at 3 months and clinical outcomes after CXL.
CONCLUSIONS: After CXL, the cornea thins and then recovers toward baseline thickness. The cause and implications of corneal thickness changes after CXL remain to be elucidated.
FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.
Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
PMID:21420594[PubMed - in process]
Would be interesting to read the full study report. Seems to this untrained and unqualified and pretty clueless person that you can't expect to gain much by way of re-thickening of a cornea post C3R. In fact, you get a bit of initial thinning. But then you recover to something approaching what you were by a process which isn't clearly understood. Interesting, but a PubMed subscription costs a couple of hundred bucks from memory. I'm interested, but not, like, that interested... I've got a new kitchen to save up for. And you should see the state of my hall carpet...
I always have a bit of a rye chuckle at the "sham-procedure control group". I know it's unavoidable. But be honest, you'd be really miffed if you ended up in that one, wouldn't you ?
Cheers all
Chris
