Abstract
We have examined the morphology of the collagen and proteoglycans in rabbit corneas that have undergone excimer laser photorefractive keratectomy using a clinical, 193 nm excimer laser. The photoablation was carried out to a stromal depth of 100 μm and a diameter of 6 mm. All ablated corneas developed a haze that was most intense between week 4 and week 8 and which showed no improvement after week 16. The corneas were stained with the cationic dye cuprolinic blue to visualise proteoglycans and were then processed for transmission electron microscopy. The ultrastructural location of proteoglycans (keratan sulphate and dermatan sulphate) was observed in the corneal wounds at different time intervals. Corneas that had undergone steroid treatment post-operatively were also examined. In the healing tissue proteoglycan filaments of abnormal size were observed, which became most prominent after 2 weeks. As healing progressed these abnormal filaments decreased but after 45 weeks some were still present, indicating that the proteoglycan content had not returned to normal.
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McDonald MB, Frantz JM, Klyce SD, Beuerman RW, Varnell R, Munnerlyn CR, et al.: Central photorefractive keratectomy for myopia: the blind eye study. Arch Ophthalmol 1990, 108: 799–808.
Zabel RW, Sher NA, Ostrov CS, Parker P, Lindstrom RL : Myopic excimer laser keratectomy: a preliminary report. Refract Corneal Surg 1990, 6: 329–34.
SundarRaj N, Geiss MJ, Fantes F, Hanna K, Anderson SC, Thompson KP, et al.: Healing of excimer ablated monkey corneas: an immunohistochemical evaluation. Arch Ophthalmol 1990, 108: 1604–10.
Hanna KD, Pouliquen YM, Savoldelli M, Fantes F, Thompson KP, Waring GO III, Samson J : Corneal wound healing in monkeys 18 months after excimer laser photorefractive keratectomy. Refract Corneal Surg 1990, 6: 340–5.
Malley DS, Steinert RF, Puliafito CA, Dobi ET : Immunofluorescence study of corneal wound healing after excimer laser keratectomy in the monkey eye. Arch Ophthalmol 1990, 108: 1316–22.
Lohmann L, Timberlake GT, Fitzke F, Gartry DS, Muir MK, McHugh JD, Marshall J : The effect of changes in corneal transparency on visual acuity after photorefractive keratectomy using an excimer laser. Invest Ophthalmol Vis Sci 1991, 32: 721.
Klyce SD, Wilson SE, McDonald MB, Liu JC, Kaufman HE : Corneal topography after excimer laser keratectomy. Invest Ophthalmol Vis Sci 1991, 32: 721.
Seiler T, Jean B, Pham T, Derse M, Bende T : Statistical analysis of myopic regression after excimer laser PRK. Invest Ophthalmol Vis Sci 1991, 32: 721.
Taylor DM, L'Esperance FA, Del Pero RA : Human excimer laser lamellar keratectomy. Ophthalmology 1989, 96: 654–63.
Talamo JH, Gollamudi S, Green WR, De La Cruz Z, Filatov V, Stark WJ : Modulation of corneal wound healing after excimer laser keratomileusis using topical mitomycin C and steroids. Arch Ophthalmol 1991, 109: 1141–6.
Tuft SJ, Zabel RW, Marshall J : Corneal repair following keratectomy: a comparison between conventional surgery and laser photoablation. Invest Ophthalmol Vis Sci 1989, 30: 1769–77.
Maurice DM : The structure and transparency of the corneal stroma. J Physiol 1957, 136: 263–86.
Cintron C, Schneider, H, Kublin CL : Corneal scar formation. Exp Eye Res 1973, 17: 251–9.
Cintron C and Kublin CL : Regeneration of corneal tissue. Dev Biol 1977, 61: 346–57.
Rawe IM, Tuft SJ, Meek KM, et al.: X-ray diffraction and electron microscope studies of rabbit corneal scar tissue. Invest Ophthalmol Vis Sci 1991, 32: 1164.
Borcherding MS, Blacik LS, Sittig RA, Bizzel JU, Breen M : Proteoglycans and collagen fibre organisation in human cornea scleral tissue. Exp Eye Res 1975, 21: 59–70.
Cho H, Covington HI, Cintron C : Immunolocalization of Type VI collagen in developing and healing rabbit cornea. Invest Ophthalmol Vis Sci 1990, 31: 1096–102.
Scott JE and Haigh M : Proteoglycan-Type 1 collagen interactions in bone and non-calcifying connective tissues. Biosci Rep 1985, 5: 71–81.
Meek KM, Elliott GF, Nave CA : Synchrotron X-ray diffraction study of bovine cornea stained with cupromeronic blue. Coll Relat Res 1986, 6: 203–18.
Katz EP, Wachtel EJ, Maroudas A : Exrafibrillar proteoglycans osmotically regulate the molecular packing of collagen in cartilage. Biochim Biophys Acta 1986, 882: 136–9.
Funderburgh JL and Chandler JW : Proteoglycans of rabbit corneas with nonperforating wounds. Invest Ophthalmol Vis Sci 1989, 30: 435–12.
Cintron C, Covington HI, Kublin CL : Morphologic analyses of proteoglycans in rabbit corneal scars. Invest Ophthalmol Vis Sci 1990, 31: 1789–97.
Rawe IM, Tuft SJ, Meek KM : Proteoglycan and collagen morphology in superficially scarred rabbit cornea. Histochem J 1992 24: 311–18.
Van Setten G-B, Koch JW, Tervo K, Lang GK, Tervo T, Naumann GOH, et al.: Expression of tenascin and fibronectin in rabbit cornea after excimer laser surgery. Invest Ophthalmol Vis Sci 1999, 32: 1247.
Scott JE, Orford CR, Hughes E : Proteoglycan—collagen arrangements in developing rat tail tendon Biochem J 1981, 195: 573–81.
Scott JE : The periphery of developing collagen fibril, Biochem J 1984, 218: 229–33.
Benedek GB : Theory of transparency of the eye Appl Optics 1971, 10: 459.
Hart RW and Farrell RA : Light scattering in the cornea. J Opt Soc Am 1969, 59: 766.
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Rawe, I., Zabel, R., Tuft, S. et al. A morphological study of rabbit corneas after laser keratectomy. Eye 6, 637–642 (1992). https://doi.org/10.1038/eye.1992.137
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DOI: https://doi.org/10.1038/eye.1992.137