To accurately assess and manage glaucoma, it is important to visualize the angle. For a surgeon to perform a laser trabeculoplasty, the correct angle must be visualized. This is just one example of various types of minimally invasive surgeries for glaucoma in Tennessee and elsewhere that require angle visualization.
A rapid and commonly used method of indirect angle assessment is the van Herick method. A study found that different levels of expertise affect the van Herick test’s sensitivity. The study discovered that the sensitivity of the test ranged from 79% for residents and 58% for technicians. A separate study evaluated risk factors for misdiagnosis when the van Herick test is used to detect angle closure.
The van Herick test is an indirect assessment method, which means it can miss angle closure. It can also miss angle pathology in certain patients, especially those with no obvious risk factors for glaucoma and a deep anterior chamber. One example that is often used is the case of a patient with an older ocular injury that has been forgotten.
Both of these studies illustrate how important it is to directly view the angle structures using gonioscopy, a test that can give a 360° view of the configuration of the angle. While gonioscopy has limitations, it is considered the best method of evaluating the angle. There are alternatives to gonioscopy, including ultrasound biomicroscopy and optical coherence tomography.
If glaucoma is missed or misdiagnosed, the consequences can be serious, including reduced vision and vision loss. A patient who has suffered vision loss or reduction due to delayed diagnosis of glaucoma can meet with a medical malpractice lawyer to explore his or her options and gain information.