Kumar et al. (1554) continue important studies of angle closure. This report on 'plateau iris', fails to distinguish plateau configuration (the anatomic finding) from the plateau syndrome ‐ in which high IOP attacks recur on dilation after iridotomy. How many, if any, of those with configuration had the syndrome. In the 1980s, we learned that onethird of eyes still look gonioscopically narrow after iridotomy, so it is no surprise to find plateau configuration to be common, nor is the rate different between European/American and Chinese persons. But, plateau syndrome is quite rare. Yet, the authors state that their work highlights 'the importance of non-pupil block mechanisms'. It certainly does not do that, unless we know that those with plateau iris (as defined) have a separate mechanism, rather than a functionally meaningless anatomic finding.

No longitudinal study has shown that a 'plateau' appearance worsens the long-term outcome

No longitudinal study has shown that a 'plateau' appearance worsens the long-term outcome of ACG. In fact, the Singapore group has shown that only 5% of PAC eyes develop optic nerve damage five years after iridotomy. We need to know whether these are more often those with plateau-looking angles and why, if plateau configuration is present in 30%, so few of them develop glaucoma damage after iridotomy. The Singapore group previously reported that 30% of PAC suspects had plateau configuration after iridotomy. Surely, if it were a serious risk factor for developing PACG, the prevalence of plateau in PACG should be higher than in PAC suspects. The fact that the rates are the same suggests that the plateau configuration is not a strong risk factor. If it were, more PACG would have plateau configuration than suspects do.

We await well-designed prospective studies to assess the true risk of plateau configuration. These should match gonioscopic location of true PAS with the clock hour at which UBM was performed, and anterior segment OCT should also be performed to assess the angle openness and iris volume, which are dramatically affected by pupil size. Standard UBM images do not include the pupil, so we have no idea how much plateau configuration changes with lighting conditions.

Biography: Harry A. Quigley, MD (Johns Hopkins University) directs the Glaucoma Service and the Dana Center for Preventive Ophthalmology and is President of the Glaucoma Research Society.