Sir,

The article by David Henson and colleagues (Eye (2003) 17: 21–26) regarding employment of specially trained optometrists to screen glaucoma referrals from community optometrists attempts to show that this is cheaper than a visit to the hospital eye department.

The cost of an eye department outpatient visit is estimated at £55, which does seem high. I wonder how the group arrived at this figure and whether it could possibly be a hospital wide average outpatient cost. Costings in the NHS are notoriously difficult to pin down, but it is very important to be sure that there is a cost advantage in eye care outside the hospital setting before these schemes are more widely recommended. In our hospital I estimate that the real cost of an outpatient visit to the glaucoma clinic is between £5 and £10 including staffing costs, overheads, and disposables. Interestingly, we have also set up an optometrist-managed secondary screening clinic for glaucoma referrals, but we use hospital-employed optometrists who work in the eye department premises. In this clinic, patients are prioritised and referred to the glaucoma clinic, and are discharged if there are no abnormal findings. Audit data on 200 patients passing through this clinic indicate a discharge rate of approximately 15%, which is considerably less than the 40% nonreferral rate in Henson's study. This variance could indicate a regional variability in the quality of optician's referrals.