Reliability and Correlation with Quality of Life Outcomes of Unified Visual Function Scale

Background Historically, descriptions of visual acuity and visual field change following intracranial procedures have been very rudimentary. Clinicians and researchers have often used basic descriptions such as “improved,” “worsened,” and “unchanged” to describe outcomes following resections of tumors affecting the optic apparatus. These descriptors are vague, difficult to quantify, and are challenging to apply in a clinical perspective. We present a novel way to describe a patient’s visual function as a combination of visual acuity and visual field assessment—Unified Visual Function Scale (UVFS). It is simple to use and can be used by surgeons, and researchers to gauge visual outcomes following tumor resection.

Objective We combined visual acuity and visual fields into three categories designed around the definition of legal blindness and fitness to drive in Canada. We then tested for inter- and intraobserver reliabilities of the UVFS, and assessed whether UVFS scores reflect visual quality of life outcomes.

Methods Six independent observers (two medical students, two neurosurgical trainees, and two neurosurgical staff members) were asked to assess visual acuity and visual fields and assign appropriate UVFS scores. These were then tested for inter- and intraobserver reliabilities. Additionally, Visual Function Questionnaire (VFQ-25) and Activities of Daily Vision Scale (AVDS) surveys were mailed out to 50 patients with previously treated perisellar meningiomas and results were analyzed against UVFS scores for correlation.

Conclusion The UVFS is a robust way to assess a patient’s vision combining visual fields and acuity. We believe it is reliable when used by clinicians, and its implementation in a clinical setting is strengthened by reflection of patient visual quality of life.