Sir,

The glaucoma referral refinement scheme reported from Manchester (Eye (2003) 17: 21–26) has potential benefits for hospital glaucoma clinics that are struggling to keep abreast of the tide of new suspect glaucoma referrals. But the alleged cost savings are doubtful. For example, the savings to the GP of £11 700 are presumably based on an estimate of GP time and expenses in passing the referral on to the hospital: is this a realistic figure?

Hospital-based screening clinics may be a cheaper alternative. For 7 years, I have run a Nurse-led Glaucoma screening clinic to assess the urgency of referrals from optometrists. Patients attend the clinic and records are taken of the history (including details of family history and medications), visual acuity, visual field (Humphrey 24-2 threshold strategy), intraocular pressures by applanation tonometry (Perkins), and nonmydriatic optic disc photographs (Topcon). The records are examined and I write to the patient, general practitioner, and optometrist recommending follow-up by the optometrist or in the glaucoma clinic according to the findings. The clinic is audited annually.

We need to allow more responsibility to optometrists and ensure there is no financial disincentive to the follow-up of glaucoma suspects in the community. In particular, visual field defects are often artefactual rather than real, and improve when the field test is repeated. Visual field tests need careful explanation, supervision, and interpretation. Noncontact tonometry should not be performed by untrained personnel. It is good practice for an optometrist to repeat both tonometry and field tests to help reduce the false positive rate. Optometrists should be able to exercise clinical judgement and not refer nonprogressive field defects in people with anomalies, for example, optic disc drusen, tilted discs, colobomas.