Glaucoma and Fitness to Drive: Using Binocular Visual Fields to Predict a Milestone to Blindness

Abstract

The IVF provides a method by which binocular visual fields can be incorporated into patient management and allows, for example, a prediction of future driver's license loss. The rate of binocular IVF sensitivity loss at 2 years of follow-up may help identify patients who could benefit from intensified intervention.

Practical landmarks for visual field disability in glaucoma

“…In particular, MD discards important spatial information about a VF defect, which is an important feature of glaucoma when assessing LFTD, but the index is readily available to clinicians. Perhaps, it is worth echoing suggestions that perimetry analysis software could include analyses such as the IVF 23. For now, results from this study can potentially aid clinicians in making treatment decisions that will affect the QoL of a patient, as well as serving to remind the clinician to refer patients with binocular VF damage to undergo the Esterman test.…”

“…However, previous research suggests that the ‘better sensitivity’ method for generating the IVF represents a good measure of the ‘true’ binocular VF in patients with glaucoma 5 22. Furthermore, the IVF has already been demonstrated as practical for assessing LFTD compared with using monocular VFs,23 and a strong correspondence between IVF and Esterman test results has been shown in glaucoma,15–17 with a minimum level of agreement equal to 88% in all cases. Disagreements between the two tests can be attributed to the higher sensitivity of the IVF due to its higher testing frequency in the central area,16 including the four points closest to fixation, which the Esterman test does not test.…”

Patients Have Two Eyes!: Binocular versus Better Eye Visual Field Indices

“…The integrated VF (IVF) offers an alternative assessment of a patient's binocular VF severity. [27][28][29][30] The IVF is estimated simply from monocular results, taking the best sensitivity values from corresponding VF locations from the two eyes, and requires no extra testing. The IVF has been shown to agree closely with the Esterman test in identifying patients with glaucomatous central defects 27 and has also been used to predict patients with glaucoma who fail the standard adopted in the United Kingdom for the VF component for fitness to drive.…”

“…The IVF has been shown to agree closely with the Esterman test in identifying patients with glaucomatous central defects 27 and has also been used to predict patients with glaucoma who fail the standard adopted in the United Kingdom for the VF component for fitness to drive. 28,30 In addition, a measure based on the IVF has been shown to be more closely related to the perceived difficulty with visual tasks in patients with glaucoma than a measure from the Esterman test. 29 Other studies of QoVL have also used the IVF approach for quantifying VF loss, 22,30 -35 and other investigators 22,36 have assessed the merit of this approach.…”

Areas of the visual field important during reading in patients with glaucoma

“…There are other methods of representing the binocular vision of patients aside from the IVF [38], but the IVF has been shown to have good concordance with quality-of-life experiences of people with glaucoma [39], performance-based measures of visual disability [40,41] as well as other binocular VF measurements [23,42].…”