title: The relationship between central corneal thickness and optic disc size in patients with primary open-angle glaucoma in a hospital-based population.
abstract: OBJECTIVE
  To investigate the relationship between central corneal thickness (CCT) and optic disc size in patients with primary open-angle glaucoma (POAG) in a hospital-based population.
  
  
  METHODS
  Data for the right eyes of 1435 White patients with POAG were included in a retrospective hospital-based study. All eyes underwent optic nerve head imaging using Heidelberg Retina Tomograph II (HRT II; Heidelberg Engineering, Heidelberg, Germany) and CCT measurement by ultrasound corneal pachymetry. Eyes with prior intraocular or corneal surgery were excluded. Low-quality HRT II images were also excluded. The impact of age, gender, CCT, intraocular pressure, cylindrical and spherical refractive error as independent factors on optic disc size was investigated in a multiple linear regression analysis.
  
  
  RESULTS
  The data for 1104 right eyes qualified for participation in the study. The median age of these patients was 65 years. The median CCT was 547 μm (25th-75th percentile 522-575 μm). The median optic disc size was 2.21 mm(2) (25th-75th percentile 1.89-2.60 mm(2)). Multiple linear regression analysis revealed that age (p = 0.001), CCT (p = 0.001) and spherical equivalent (p = 0.049) were correlated to disc size according to the following formula: disc area = -0.004 × age - 0.001 × CCT - 0.014 × spherical equivalent +3.290. R(2) of the whole model was 0.021. Univariate regression analysis between age and disc area provided R(2) = 0.008 with p = 0.002. Univariate regression analysis between disc area and CCT provided R(2) = 0.005 with p = 0.02.
  
  
  CONCLUSIONS
  In this retrospective hospital-based study we could not detect a clinically relevant correlation between optic disc size and CCT. The correlation between CCT and disc size and between age and disc size were statistically significant, but the R(2) values were very low. The results of the study are biased because of its hospital-based design, so the results of the study need to be confirmed in a large population-based study.
authors.affiliation: Department of Ophthalmology, Carl Gustav Carus University Hospital, Dresden, Germany. naim.terai@uniklinikum-dresden.de
authors.forename: Naim
authors.initials: N
authors.lastname: Terai
authors.forename: Eberhard
authors.initials: E
authors.lastname: Spoerl
authors.forename: Lutz E
authors.initials: LE
authors.lastname: Pillunat
authors.forename: Eberhard
authors.initials: E
authors.lastname: Kuhlisch
authors.forename: Eckart
authors.initials: E
authors.lastname: Schmidt
authors.forename: Andreas G
authors.initials: AG
authors.lastname: Boehm
mesh_terms: D000368:Aged; D003315:Cornea / Q000473:pathology*; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology*; D009929:Organ Size; D012189:Retrospective Studies; D014054:Tomography