title: Histologic and ultrastructural changes in corneas with granular and macular dystrophy after excimer laser phototherapeutic keratectomy.
abstract: OBJECTIVE
  The histologic changes after phototherapeutic keratectomy (PTK) in corneas with granular and macular dystrophy were studied.
  
  
  METHODS
  We studied 3 corneas of 2 patients (1 granular, 2 macular dystrophy), who underwent penetrating keratoplasty (PK) at 0.8, 2.16, and 3.25 years after PTK; and 11 corneas (controls) from 10 PK patients (5 granular, 6 macular dystrophy) by light microscopy and by transmission electron microscopy. PTK was performed by using the Asclepion-Meditec MEL 60 excimer laser.
  
  
  RESULTS
  After PTK the epithelium (15-40 versus 5-100 microm), and the upper stromal collagen lamella thickness (50-75 versus 50-100 microm) were less irregular than for the controls. In 1 eye (macular dystrophy) 10 months after PTK an acid mucopolysaccharide-positive band was detected in the subepithelial stroma, which could be removed by hyaluronic acid digestion. This fact suggests that it was "haze" formed after PTK, rather than a subepithelial recurrence of the dystrophy. All PTK corneas had deposits in the mid- and posterior stroma. Concerning controls, deposits were detected under the epithelium in all corneas. Electron microscopy of the study corneas revealed a mostly continuous basal lamina, occasionally forming projections into the subepithelial stroma, and large numbers of well-developed hemidesmosomes (5.2 +/- 0.8 per microm membrane length) present at greater density than in the controls (3.5 +/- 0.8).
  
  
  CONCLUSIONS
  In stromal dystrophies, PTK was effective in removing large subepithelial stromal plaques. There were no subepithelial recurrences, and hemidesmosome density was increased.
authors.affiliation: 1st Department of Ophthalmology, Semmelweis University, Budapest, Hungary. nszentmary@hotmail.com
authors.forename: Nóra
authors.initials: N
authors.lastname: Szentmáry
authors.forename: Berthold
authors.initials: B
authors.lastname: Seitz
authors.forename: Achim
authors.initials: A
authors.lastname: Langenbucher
authors.forename: Ursula
authors.initials: U
authors.lastname: Schlötzer-Schrehardt
authors.forename: Carmen
authors.initials: C
authors.lastname: Hofmann-Rummelt
authors.forename: Gottfried O H
authors.initials: GO
authors.lastname: Naumann
mesh_terms: D000328:Adult; D000368:Aged; D003315:Cornea / Q000601:surgery / Q000648:ultrastructure*; D003317:Corneal Dystrophies, Hereditary / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D015948:Keratoplasty, Penetrating; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D018903:Photorefractive Keratectomy