Keratan Sulfate And Chondroitin/Dermatan Sulfate In Maximally Recovered Hypocellular Stromal Interface Scars Of Postmortem Human Lasik Corneas

PURPOSE. To analyze the amounts and distributions of nonsulfated and sulfated keratan sulfate (KS) and chondroitin/dermatan sulfate (CS/DS) disaccharides in the interface wound of human postmortem LASIK corneas in comparison with normal control corneas.METHODS. Corneal stromal tissue samples from central and paracentral hypocellular primitive stromal interface scars of human LASIK corneas and from similar regions of normal control corneas were collected by laser capture microdissection (LCM) and subsequently were digested with specific glycosidase enzymes. Digests were directly analyzed by electrospray ionization tandem mass spectrometry (ESI-MS/MS).RESULTS. Concentrations of both monosulfated GlcNAc(6S)-beta-1,3-Gal (MSD2) and disulfated Gal (6S)-beta-1,4-GlcNAc(6S) (DSD) KS disaccharides from the LASIK interface scars were significantly lower than in normal control corneal stromas. No significant difference was found for the concentration of nonsulfated (NSD) KS disaccharides in LASIK interface scars compared with normal controls. The concentration of Delta UA-beta-1,3-GalNAc(6S) (Delta di-6S) CS/DS disaccharides from the LASIK interface scar was significantly higher than normal corneal stroma, whereas concentrations of Delta UA-beta-1,3-GalNAc(4S) (Delta di-4S) and nonsulfated Delta di-OS CS/DS disaccharides demonstrated no significant differences from normal corneas.CONCLUSIONS. The profiles of KS and CS/DS disaccharides in LASIK interface scars are significantly different from those in normal cornea stromal tissue, as revealed by LCM and ESI-MS/MS.