• Written By: Darrell WuDunn, MD, PhD

    This retrospective study found that most glaucoma patients under clinical care are not at high risk of becoming blind.

    Unlike prior studies that estimated the risk of blindness over time, this study’s researchers used actuarial statistics to determine median life expectancies and estimated the likelihood of developing visual field-defined visual disability or blindness before death. Thus, this study may give a more useful estimate of lifetime risk of blindness.

    They calculated the rate of visual field loss over three years in 3,790 glaucoma patients.

    Of the 3,359 patients with both eyes followed, 5.2 percent were predicted to progress to statutory blindness, defined as mean deviation (MD) of ‑22 dB or worse, with a further 10.4 percent reaching visual impairment in their lifetime (MD ‑14 dB or worse).

    Only 3 percent of eyes progressed at faster than ‑1.5 dB/year. More than 90 percent of patients predicted to progress to statutory blindness had an MD worse than ‑6 dB in at least one eye at presentation.

    The major limitations of this study are its assumption that visual field MD loss progresses linearly and that MD is a good measure of visual disability and blindness.

    The results suggest that more resources should be concentrated toward detecting glaucoma before it progresses beyond early damage.