1. The earliest visual field defect in a patient with ocular hypertension who converts to primary open-angle glaucoma (POAG) is usually a combined form of localized and diffuse loss. It is uncommon to see only one type early on. This is important, because many ophthalmologists may only be looking for a classic arcuate defect and that would not be in the best interest of the patient with ocular hypertension. Even though arcuate defects are the hallmark of glaucoma, the Ocular Hypertension Treatment Study (OHTS) demonstrated that early on, a diffuse loss may accompany the arcuate defect or potentially diffuse loss may occur by itself in early disease.1

2. Localized- or arcuate-type change is best picked up by evaluating the total- and pattern-deviation plots.

3. Diffuse change is best detected be checking the mean deviation.

4. In more than 50% of patients in OHTS who developed glaucoma, the optic nerve worsened while the visual field remained normal. If you are relying mainly on the classic arcuate visual field defect to diagnose POAG, the horse is well out of the barn.

5. If you see a mild generalized loss of sensitivity in a patient with ocular hypertension, it may be the first sign of field damage. Repeat the field and re-evaluate the disc. We clinicians can no longer simply attribute generalized field loss to a nonspecific event; it could be a sign of early POAG.

6. Until we learn more, it is best to examine both longitudinal and cross-sectional visual field analyses to determine if there is a true change in sensitivity.

7. In an ocular hypertensive patient similar to those in the OHTS with initially normal visual fields, even after two reliable abnormal visual fields in a row, the next visual field was normal 36% of the time. After one abnormal visual field the next visual field was normal 85.9% of the time. However, after three abnormal visual fields, the next visual field was normal only 12% of the time. Visual fields need to be repeated several times to be sure of a definitive glaucomatous defect. Obviously, the visual field should be correlated with the disc at every visit to obtain a more meaningful picture of the overall glaucomatous process.

  1. Kass MA, Heuer DK, Higginbotham EJ, et al. The Ocular Hypertension Treatment Study—a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma. Arch Ophthalmol. 2002;120(6):701-713.