Table 1.1

Influence of corneal status, thickness and tear film on the intraocular pressure (IOP) value measured with the Goldmann Applanation Tonometry.

Cornea StatusIOP reading erroneously highIOP reading erroneously low
Thin central cornea x
Thick central corneax
Epithelial oedema x
Excessive tear film x
Insufficient tear filmx
Corneal refractive surgery* x
  • *Corneal refractive surgeries alter tonometry reading since they modify thickness, curvature and structure of the cornea.