title: Corneal astigmatism in Graves' ophthalmopathy.
abstract: OBJECTIVE
  To describe corneal astigmatism in patients under the age of 55 years with Graves' ophthalmopathy and to compare it to a control group.
  
  
  METHODS
  Retrospective, nonrandomized comparative observational case series. A total of 109 patients with inactive Graves' ophthalmopathy and 109 age- and gender-matched control individuals without Graves' ophthalmopathy were examined with manual corneal keratometry. In the Graves' patients, 52% had a CT scan available for review, and 41% underwent orbital, strabismus, and/or eyelid surgery with a follow-up of keratometry over a mean period of 1.7 years after surgery.
  
  
  RESULTS
  For the dioptres, there was a statistically significant difference between the Graves' and the control eyes at 3-3.25 dioptres in both eyes (t-test, right eyes, P=0.042; left eyes, P=0.041). For the meridians, the astigmatism was found to be greater at the meridians 95-100 degrees (t-test, P=0.044) and 105 degrees -110 degrees (t-test, P=0.017) in the right eyes only. In 10 (9%) Graves' patients, the astigmatism had caused newly acquired reduced visual acuity. Greater astigmatism in dioptres did not correlate with specific CT scan findings (chi(2)-test, df=2, P=0.187). Following orbital, strabismus, and eyelid surgery, the dioptres and meridians of the astigmatism did not change in 56 (68%) and 66 (81%) eyes, respectively.
  
  
  CONCLUSIONS
  Graves' ophthalmopathy may be associated with greater with-the-rule corneal astigmatism, which, overall, is not influenced by orbital, strabismus, or eyelid surgery. The astigmatism may possibly be caused by soft-tissue fibrosis in the superolateral orbital region.
authors.affiliation: Orbital Clinic, Department of Ophthalmology, University Hospital Leuven, Leuven, Belgium. Ilse.Mombaerts@uz.kuleuven.ac.be
authors.forename: I
authors.initials: I
authors.lastname: Mombaerts
authors.forename: S
authors.initials: S
authors.lastname: Vandelanotte
authors.forename: L
authors.initials: L
authors.lastname: Koornneef
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000209:etiology*; D003316:Corneal Diseases / Q000209:etiology*; D019781:Corneal Topography; D005143:Eyelids / Q000601:surgery; D005260:Female; D049970:Graves Ophthalmopathy / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009915:Orbit / Q000601:surgery; D012189:Retrospective Studies; D013285:Strabismus / Q000601:surgery; D014057:Tomography, X-Ray Computed; D014792:Visual Acuity