Bill Harvey: Got to see it from my angle

I was asked the other day about referral of patients based upon narrow angles. There seems to be some confusion about whether to refer patients with a van Herrick grade of 2. I stated that, assuming there were no other factors of note, referral of a grade 2 angle would be inappropriate. Indeed, this would probably include most elderly patients and many hyperopes. Yet more important from a personal viewpoint, this would include me.

The confusion seems to have arisen from a sentence in the College guidelines as follows –‘Patients with peripheral anterior chamber width of one quarter or less of the corneal thickness (van Herrick grade 2) should be referred to secondary eye care services.’ Few would argue that, when the anterior chamber is less than a quarter the corneal thickness, something should be done. The problem here is that this represents grade 1. Grade 2 is where the chamber gap is one quarter to a half the corneal thickness, and the guidelines here might be better revised to state grade 1.