Influence of corneal status, thickness and tear film on the intraocular pressure (IOP) value measured with the Goldmann Applanation Tonometry.
| Cornea Status | IOP reading erroneously high | IOP reading erroneously low |
|---|---|---|
| Thin central cornea | x | |
| Thick central cornea | x | |
| Epithelial oedema | x | |
| Excessive tear film | x | |
| Insufficient tear film | x | |
| Corneal refractive surgery* | x |
*Corneal refractive surgeries alter tonometry reading since they modify thickness, curvature and structure of the cornea.