Comparison of optometrist glaucoma referrals against published guidelines

Purpose: To examine if community optometrists follow published guidelines for referral of patients with suspect glaucoma to the hospital eye service.

Methods: A retrospective audit of new optometrist-initiated referrals to the Glaucoma Service at Moorfields Eye Hospital, London was performed. Clinical data from referral letters recorded included evidence of intraocular pressure (IOP) measurement and tonometer used. Referral letter information was compared to 2009 guidelines published jointly by the College of Optometrists and Royal College of Ophthalmologists on referring glaucoma suspect patients.

Results: A total of 289 new patients were seen in the Glaucoma Service over a 6 week period from 4th January 2011; a 100% hospital record retrieval rate was obtained. Of these, 114 (39%) were optometrists initiated referrals. Optometrist letters were available for 105 patients. IOP measurements were recorded in 102 (97%); most practitioners used non-contact tonometry (NCT; n = 69; 68%). Practitioners recorded <4 NCT readings per eye (4 readings: n = 3, 4%; 3 readings: n = 42, 61%; 2 readings: n = 6, 9%; 1 reading: n = 18, 26%). Seventy-seven patients (73%) reported with raised IOP as the main referral reason; of these, 33 (43%) were referred with raised IOP in isolation. NCT was the instrument used in the majority of these raised IOP cases (n = 56; 73%). In cases where raised IOP in isolation was the referral reason, 24 (73%) were recorded using NCT; 10 (30%) provided repeat IOP measurement data in the letter. One hundred and two (97%) referred patients attended the hospital appointment. Thirty (29%) were deemed not to have glaucoma, with the remainder diagnosed with ocular hypertension (n = 25; 25%), glaucoma suspect/glaucoma (n = 35, 34%) or narrow angles requiring intervention (n = 12, 12%). Thirty of the 33 patients referred with raised IOP in isolation attended their hospital visit. Ten (33%) of these patients were subsequently discharged. Six (20%) patients had IOP within normal limits when measured with applanation tonometry; all of these patients were kept within the service.

Conclusions: Community optometrists using NCT for measurement should be reminded of the guidelines on number of readings to take and also the value of repeating NCT measures when appropriate. This may help to increase the accuracy of glaucoma suspect referrals to hospital eye service.