(this is an OCT instrument used for glaucoma testing and treatment)
Most eye patients think of eye pressures when I mention Glaucoma. That is because for most of the past century eye pressures were the most important way to check for glaucoma. Air-Puff, Tonopen, and blue light Goldman applanation are used to measure your pressure on almost every eye exam. The other method is the dilated eye exam with an ophthalmoscope and a trained doctor. We observe the size of the cup inside the disk of the optic nerve. The cup gets larger as the nerve shrinks and the vision fades.
So Glaucoma is actually a progressive nerve damage associated with the pressure of the eye and a painless loss of vision. The OCT instrument now measures nerve damage two ways.
- Nerve fiber layer thickness is measured and since it shrinks with glaucoma damage, a loss of thickness can show progressive damage.
- The Nerve begins at the retina ganglion cell, so I also measure the health of the ganglion cells as well.
So with OCT, a more specific and sensitive test is made for glaucoma and progressive eye disease.
Other factors that we measure for glaucoma beyond OCT include:
- Visual Field which measures the decibels of vision looking at multiple points.
- Corneal thickness or pachymetry
- Corneal Angle which helps to determine if the glaucoma is open angle or closed angle
- Gonioscopy is used to see if pigment is clogging the angle.
- OHTS calculation is used to provide risk of progression calculation.
Treatment goals are to stabilize the condition and stop further vision loss. Often the vision cannot be restored so that is why prevention is so important.
I typically treat the glaucoma by lowering the eye pressures with prescription eye drops, similar to the way you treat blood pressure. Several surgeries can lower the pressure also.