Corneal Biomechanics as a Risk Modifier: Last-Month Evidence

This audio article is from VisualFieldTest.com.Read the full article here: https://visualfieldtest.com/en/corneal-biomechanics-as-a-risk-modifier-last-month-evidenceTest your visual field online: https://visualfieldtest.comSupport the show so new episodes keep coming: https://www.buzzsprout.com/2563091/supportExcerpt:Understanding Corneal Biomechanics and Glaucoma Risk Glaucoma is an eye disease where damage to the optic nerve leads to vision loss. The main known risk factor has long been high intraocular pressure (IOP). However, newer research shows the biomechanical properties of the cornea – essentially how “springy” or deformable the cornea is – also influence glaucoma risk. Two key measures are corneal hysteresis (CH) and dynamic corneal response (DCR) parameters. CH measures how well the cornea absorbs and dissipates energy (think of it as corneal “shock absorption”). DCR parameters come from devices like the Corvis ST, which use a quick air puff and high–speed camera to record corneal deformation. These measures are now easier to get in the clinic thanks to instruments such as the Ocular Response Analyzer (ORA) and Corvis ST () (). Recent evidence suggests both CH and DCR can help predict glaucoma development and progression beyond IOP and corneal thickness (CCT). Measuring Corneal Hysteresis and Corneal Response The ORA (introduced in 2005) uses an air puff and infrared light to estimate CH (). It reports two values: CH and a related Corneal Resistance Factor (CRF). The newer Corvis ST system uses a high-speed Scheimpflug camera (over 4,300 frames/sec) to visualize the actual corneal movement during an air puff (). It yields many dynamic response metrics (like deformation amplitude, inverse radius, stiffness) beyond CH () (). Importantly, each device produces different parameters, and they are not interchangeable. For example, one study found that the Corvis ST’s “biomechanically corrected” IOP (bIOP) did not match the ORA’s cornea-compensated IOP (IOPcc) – the two methods showed weak agreement and should not be used interchangeably (). In practical terms, CH (from ORA) and DCR metrics (from Corvis) reflect related but distinct corneal properties () (). Clinicians are beginning to incorporate these tests: one expert review even recommends checking corneal biomechanics at baseline in all glaucoma patients and suspects (). This means measuring CH (and possibly Corvis metrics) as part of the initial exam. In summary, corneal biomechanics can now be measured clinically, and experts suggest doing so in glaucoma care () (). ... Continue reading at https://visualfieldtest.com/en/corneal-biomechanics-as-a-risk-modifier-last-month-evidenceSupport the show