• Quantifying Quality of Life in Cases of Good Unilateral Vision

    By Lynda Seminara
    Selected By: Stephen D. McLeod, MD

    Journal Highlights

    Ophthalmology, July 2018

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    Utility data are important for perform­ing reliable cost-utility analyses. By convention, normal health is assigned a utility value of 1, and death a utility value of 0. Ophthalmic vision utilities vary depending on whether 1 or both eyes have limited vision. For example, bilateral vision of 20/20 to 20/25 in conjunction with ocular disease has been associated with a utility of 0.97, whereas 20/40 vision bilaterally has a utility of 0.80. In a study for the Oph­thalmic Utility Research Study Group, Brown et al. looked at patient time-tradeoff vision utilities for quantifying vision-related quality of life among pa­tients with good vision in at least 1 eye. Their research showed utilities ranging from 0.94 to 0.79, depending on visual acuity in the fellow eye.

    All told, 586 patients participated in the study, which included complete eye exams, personal interviews, and validated methodology. The common 2-question interview was used to measure time-tradeoff vision utilities for patients with good vision in 1 eye (20/20-20/25) and vision that ranged from no light perception to 20/20 in the fellow eye. Participants were asked how long they expected to live and how much of that time they would be willing to trade for an intervention that would permanently return their vision to normal. The utility was calculated by subtracting the proportion of remain­ing hypothetical time traded from 1.0. The anchors were death (0.00) and normal vision bilaterally (1.00).

    The mean time-tradeoff vision utility was 0.79 for patients whose fellow-eye vision had no light percep­tion and 0.87 for those with fellow-eye vision ranging from counting fingers to light perception. Fellow-eye vision of 20/200 to 20/400, 20/60 to 20/100, 20/30 to 20/50, and 20/20 to 20/25 yielded time-tradeoff utilities of 0.88, 0.88, 0.87, and 0.94, respectively.

    This study demonstrated a vision utility of 0.88 when 1 eye has good vision and the fellow eye has vision between 20/30 and light perception. If visual acuity in the fellow eye returns to 20/20 to 20/25, the utility improves. Similarly, if fellow-eye vision declines to no light perception, the utility worsens. The authors noted that this informa­tion may improve estimations of actual gains in quality-adjusted life-years be­cause it is based on patient preferences.

    The original article can be found here.