CLINICAL: Glaucoma

Gonioscopy’s Gravity

Lens enables subtle secondary glaucoma differentiation

Recently, I realized my diagnostic lens case felt lighter, so I opened it and discovered I was missing my gonioscopy lens! While doing a quick accounting of the other lenses, I had two immediate thoughts: First, I was reminded of how each of the remaining lenses provide irreplaceable information — information that, in their unique ways, help lead to an accurate diagnosis and, ultimately, a proper treatment. Second, a missing gonioscopy lens results in missing information — information that helps lead to an accurate diagnosis and, ultimately, the proper treatment for glaucoma.

Here, I provide advice on how optometrists can best utilize these important lenses.


I have found it helpful to pair gonioscopy with pachymetry, another tool that, as I explain to patients, helps me “better understand their eye pressures.” As such, I feel that this procedure should be performed on all new glaucoma suspect/glaucoma patients and then again (and again), especially if there is increased or asymmetric IOPs that could be due to any of the secondary glaucoma etiologies. (See “Table 1. Gonioscopy Chart,” left.)

Table 1. Gonioscopy Chart

Additionally, I suggest using a glaucoma flow sheet to document when gonioscopy was performed while being sure to include any notes, such as “risk factor for possibly narrowing,” “a good candidate for SLT” or “inferior recession from 5:00 - 7:00,” that may be helpful in deciding on management in moving forward.


When O.D.s use their gonioscopy lenses in glaucoma evaluations, they find irreplaceable information on why a patient’s IOPs are elevated, risk of fluctuating or further elevated IOPs and best treatments. As optometrists do so, they will find potentially treatment-modifying information that will benefit patients and their prognoses. OM