title: Peripheral hypertrophic subepithelial corneal degeneration: characterization, treatment and association with human leucocyte antigen genes.
abstract: OBJECTIVE
  To evaluate the efficacy of keratectomy in treating irregular astigmatism caused by peripheral hypertrophic subepithelial corneal degeneration (PHSD) and to study the possible underlying immunological risk factors.
  
  
  METHODS
  Patients (14 eyes) with diagnosed PHSD were treated with superficial keratectomy with or without the assistance of phototherapeutic keratectomy (VisX S4; VisX Inc., Santa Ana, CA, USA). Thirteen patients were subjected to analysis of human leucocyte antigen (HLA) genes, complement C4 gene numbers and total plasma immunoglobulin levels. Immunological risk factors between patients and a control group comprising 150 individuals were compared.
  
  
  RESULTS
  The mean preoperative best spectacle corrected visual acuity (BCVA) improved from 0.16 ± 0.22 (LogMAR scale range 0-0.7) to 0.06 ± 0.13 (-0.1-0.4) (p < 0.01). The mean preoperative astigmatism decreased significantly from 3.8 ± 2.1 D (range 1.2-8.2) to 2.1 ± 1.4 (range 0.6-5.0, p = 0.02) based on corneal topography. The HLA-B*44 allele and the ancestral haplotype (AH) 8.1 were found significantly more often in PHSD patients than in controls (both p = 0.03). No differences in the C4 genes were found.
  
  
  CONCLUSIONS
  Astigmatism secondary to PHSD can be effectively treated with keratectomy. Peeling of the fibrotic tissue reduced astigmatism and improved visual performance. We suggest that HLA-B*44 allele and AH 8.1 haplotype are immunological factors predisposing to the development of PHSD. The consequent disruption/alteration of the limbal barrier may lead to corneal peripheral fibrous formation inducing astigmatism.
authors: Cornea Service, Helsinki University Eye Hospital, Helsinki, FinlandTransplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, FinlandDivision of Cardiology, Department of Medicine, Helsinki University Central Hospital, Helsinki, FinlandImmunodeficiency Unit, Division of Infectious Diseases, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland.
authors: Petri J
authors: PJ
authors: Järventausta
authors: Juha M
authors: JM
authors: Holopainen
authors: Waldir N
authors: WN
authors: Zalentein
authors: Riitta
authors: R
authors: Paakkanen
authors: Annika
authors: A
authors: Wennerström
authors: Mikko
authors: M
authors: Seppänen
authors: Marja-Liisa
authors: ML
authors: Lokki
authors: Timo M T
authors: TM
authors: Tervo
mesh_terms: D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000175:diagnosis / Q000235:genetics / Q000601:surgery; D003181:Complement C4 / Q000235:genetics; D003317:Corneal Dystrophies, Hereditary / Q000175:diagnosis / Q000235:genetics* / Q000601:surgery*; D019781:Corneal Topography; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D059948:HLA-B44 Antigen / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D006984:Hypertrophy; D007136:Immunoglobulins / Q000032:analysis; D008297:Male; D008875:Middle Aged; D018903:Photorefractive Keratectomy; D012029:Refraction, Ocular / Q000502:physiology; D012307:Risk Factors; D014792:Visual Acuity / Q000502:physiology
chemical_list: D003181:Complement C4; D059948:HLA-B44 Antigen; D007136:Immunoglobulins
keywords: complement C4; corneal peripheral degeneration; haplotype; human leucocyte antigen; phototherapeutic keratectomy