Whether your practice has a designated diagnostic technician, or each technician is responsible for doing testing it is vital that each person performing diagnostic testing is trained on each piece of equipment they are expected to operate. Part of that training should include how to trouble shoot common scenarios that could affect the testing outcomes, such as a patient who is unable to hold their head in the proper position or has difficulty viewing the fixation target.
As discussed in Part 1 each technician should be trained thoroughly and understand why they are performing the test. For example, an optic nerve OCT is done for glaucoma patients versus a macular OCT is looking for macular issues. In this blog we will focus primarily on performing an Optical Coherence Tomography (OCT), Lenstar/IOL Master and topography.
When performing an OCT, the technician should be aware that severe glaucoma and advanced AMD patients may have difficulty finding a fixation target and they may need to provide additional guidance to these patients. Most OCT devices have a way to enlarge the fixation targets and auto adjust to try to get a clearer image. For a macular OCT have the patient look straight ahead and make scan adjustments to compensate. For severe glaucoma patients consider having them look at your hand as a fixation target if they cannot find the OCT fixation target. If the patient has neck or mobility issues the technician should take a series of measurements as quickly as possible and keep the best image. It’s generally a good rule to obtain the best scan possible in 5 minutes or less.
As with any testing, low vision or mobility issues can make getting an accurate topography or Lenstar/IOL Master reading difficult. To improve outcomes, try to get accurate scans quickly as possible before the patient becomes uncomfortable or frustrated. Educate the patient on approximate timing for each measurement. Patients should blink during these measurements to prevent dryness, instruct the patient to do “short, quick blinks.” This way when you do need the patient to hold their eyes open wide for a few seconds the eye is not already dry. Remember to talk the patient through the process and let them know they are doing a great job. Obtaining an Lenstar/IOL Master on a dense cataract can be difficult and the technician should obtain as many scans as possible. Ensure that at least 5 acceptable measurements are taken with acceptable standard deviations for axial length and keratometry determined by the ophthalmologist.
If low reliability or persistent issues arise consider contacting the manufacturer to help you troubleshoot. Routine maintenance and cleaning according to manufacturer specifications of the equipment is imperative. Consider assigning a technician to these tasks to ensure they are done properly and timely.