Pachymetry is a simple, painless test that quickly measures the thickness of the cornea.
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Why Measure Corneal Thickness?
Pachymetry can tell healthcare providers if the cornea is swollen. Medical conditions such as Fuch’s Dystrophy can increase fluid in the cornea and cause an increase in overall thickness.Even wearing contact lenses can sometimes cause significant corneal swelling.This may be difficult to see under the microscope. However, pachymetry will show a definite increase in thickness.
Corneal thickness is extremely important in refractive surgical procedures such asLASIK. Knowledge of corneal thickness is important to determine if a person is a candidate for laser vision correction. Because part of the procedure includes removing tissue which will leave the corneal thinner, it is important to know exactly how much will remain. Some people may have a cornea that is just much thinner than normal. It does not cause problems or disease, but it could spell tragic vision loss if a refractive procedure is performed on someone whose cornea is extremely thin.
How Pachymetry Is Performed
Optical Pachymetry:Optical pachymeters vary on design. Some optical pachymeters are designed to be mounted onto a biomicroscope that eye healthcare providers use called the slit lamp. Other devices can measure pachymetry using specular microscopy. This device does not come into direct contact with the cornea. One type of optical pachymetry that has gained in popularity is OCT oroptical coherence tomographypachymetry. OCT pachymetry also does not touch the cornea to achieve the measurements.
OCT uses a principle called optical interferometry. Another optically based method using something called Scheimpflug imaging is very good at obtaining multiple peripheral measurements of corneal thickness in addition to central corneal thickness and obtain these measurements very quickly. The one drawback of optical pachymetry is that insurance companies traditionally pay for ultrasound pachymetry and not always for optical pachymetry so it is possible that your healthcare provider may ask you for payment.
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Vedana G, Villarreal G Jr, Jun AS.Fuchs endothelial corneal dystrophy: current perspectives.Clin Ophthalmol. 2016;10:321–330. doi:10.2147/OPTH.S83467National Research Council (US) Working Group on Contact Lens Use Under Adverse Conditions. Contact Lens Use Under Adverse Conditions: Applications in Military Aviation.Adverse Effects of Contact Lenses. 1990.Drake MV.The importance of corneal thickness.Glaucoma Research Foundation[internet]. 2017.Kim JW, Chen PP.Central corneal pachymetry and visual field progression in patients with open-angle glaucoma.Ophthalmology. 2004;111(11):2126-32. doi:10.1016/j.ophtha.2004.04.029Pillunat KR, Waibel S, Spoerl E, Herber R, Pillunat LE.Comparison of Central Corneal Thickness Measurements Using Optical and Ultrasound Pachymetry in Glaucoma Patients and Elderly and Young Controls.J Glaucoma. 2019;28(6):540-545. doi:10.1097/IJG.0000000000001231
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Vedana G, Villarreal G Jr, Jun AS.Fuchs endothelial corneal dystrophy: current perspectives.Clin Ophthalmol. 2016;10:321–330. doi:10.2147/OPTH.S83467National Research Council (US) Working Group on Contact Lens Use Under Adverse Conditions. Contact Lens Use Under Adverse Conditions: Applications in Military Aviation.Adverse Effects of Contact Lenses. 1990.Drake MV.The importance of corneal thickness.Glaucoma Research Foundation[internet]. 2017.Kim JW, Chen PP.Central corneal pachymetry and visual field progression in patients with open-angle glaucoma.Ophthalmology. 2004;111(11):2126-32. doi:10.1016/j.ophtha.2004.04.029Pillunat KR, Waibel S, Spoerl E, Herber R, Pillunat LE.Comparison of Central Corneal Thickness Measurements Using Optical and Ultrasound Pachymetry in Glaucoma Patients and Elderly and Young Controls.J Glaucoma. 2019;28(6):540-545. doi:10.1097/IJG.0000000000001231
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Vedana G, Villarreal G Jr, Jun AS.Fuchs endothelial corneal dystrophy: current perspectives.Clin Ophthalmol. 2016;10:321–330. doi:10.2147/OPTH.S83467National Research Council (US) Working Group on Contact Lens Use Under Adverse Conditions. Contact Lens Use Under Adverse Conditions: Applications in Military Aviation.Adverse Effects of Contact Lenses. 1990.Drake MV.The importance of corneal thickness.Glaucoma Research Foundation[internet]. 2017.Kim JW, Chen PP.Central corneal pachymetry and visual field progression in patients with open-angle glaucoma.Ophthalmology. 2004;111(11):2126-32. doi:10.1016/j.ophtha.2004.04.029Pillunat KR, Waibel S, Spoerl E, Herber R, Pillunat LE.Comparison of Central Corneal Thickness Measurements Using Optical and Ultrasound Pachymetry in Glaucoma Patients and Elderly and Young Controls.J Glaucoma. 2019;28(6):540-545. doi:10.1097/IJG.0000000000001231
Vedana G, Villarreal G Jr, Jun AS.Fuchs endothelial corneal dystrophy: current perspectives.Clin Ophthalmol. 2016;10:321–330. doi:10.2147/OPTH.S83467
National Research Council (US) Working Group on Contact Lens Use Under Adverse Conditions. Contact Lens Use Under Adverse Conditions: Applications in Military Aviation.Adverse Effects of Contact Lenses. 1990.
Drake MV.The importance of corneal thickness.Glaucoma Research Foundation[internet]. 2017.
Kim JW, Chen PP.Central corneal pachymetry and visual field progression in patients with open-angle glaucoma.Ophthalmology. 2004;111(11):2126-32. doi:10.1016/j.ophtha.2004.04.029
Pillunat KR, Waibel S, Spoerl E, Herber R, Pillunat LE.Comparison of Central Corneal Thickness Measurements Using Optical and Ultrasound Pachymetry in Glaucoma Patients and Elderly and Young Controls.J Glaucoma. 2019;28(6):540-545. doi:10.1097/IJG.0000000000001231
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