Download CATS_scheme_V4 - Sheffield Local Optometric Committee

Contact Applanation Tonometry Scheme (CATS)
The aim of this scheme is to reduce patient referrals into the Hospital Eye Services (HES) and into the
Sheffield PEARS scheme by providing appropriate funding to Community Optometrists (CO’s) to
undertake contact applanation tonometry where the need arises.
Reduced referrals to the HES means that more patients will be managed within the primary care
setting which will reduce patient anxiety, increase capacity within the HES and provide a more cost
effective service.
Reduced referrals into the PEARS scheme means optometrists can manage more of their own
patients without the need for referral, this will reduce the number of referrals sent for optometry triage
and will provide a more cost effective service.
Background
NICE clinical guideline 85 (Diagnosis and management of chronic open angle glaucoma and ocular
hypertension) issued 22 April 2009, sets out how best to diagnose chronic open angle glaucoma
(COAG) and ocular hypertension (OHT), how people with COAG and OHT or at risk of COAG should
be monitored, and which treatments should be considered.
The majority of CO’s measure intra-ocular pressure (IOP) using a non contact tonometer (NCT). This
method of measurement is considered by NICE to be inaccurate compared with the gold standard
method, the Goldmann Applanation Tonometer (GAT). The use of contact applanation tonometry is
not a requirement of the GOS sight test, nor is it funded. It is however a ‘core competency’ that all
optometrists should be able to perform.
OHT is defined by NICE guidelines as repeatable IOP over 21 mmHg as measured by Goldmann
applanation tonometry. By defining the criteria and procedures for diagnosis, NICE have, by
implication, created a referral threshold. Previously the threshold for OHT was set by local
ophthalmologists and in many cases was around 25 mmHg. The lowering of the effective threshold
has increased the referrals by CO’s who measure IOP’s using NCT methods. Referral numbers have
therefore increased not only for patients with genuine IOP over 21mmHg, but also for those with
unverified raised IOP.
Relevant Pre-Existing Schemes
Glaucoma referral refinement (GRR): This scheme provides funding for accredited optometrists to
perform further investigation of their own patients presenting with signs suggestive of glaucoma. For a
fee of £35, the patient will undergo dilated slit lamp binocular indirect ophthalmoscopy (BIO) of the
optic nerve, full threshold visual field analysis, Van Herrick assessment of the depth of the anterior
angle, slit lamp examination of the posterior cornea and applanation tonometry. Repeat / follow up
investigations are possible for £35.
Primary Eye care Assessment and Referrals Service (PEARS): This service provides funding for
accredited optometrists to perform further investigations or treatment of patients with a variety of eye
conditions that may not require a hospital assessment. Optometrists may assess their own patients or
receive referrals from other optometrists via the referral information service (RIS) following optometric
triage. Recently a significant percentage of referrals to the PEARS scheme have been for patients
with raised IOP using NCT. For a fee of £45, these patients will undergo dilated slit lamp binocular
indirect ophthalmoscopy (BIO) of the optic nerve, full threshold visual field analysis, Van Herrick
assessment of the depth of the anterior angle, slit lamp examination of the posterior cornea and
applanation tonomtery. Repeat / follow up investigations can be done for a fee of £25.
Description of Service
Patients indentified as having IOP’s above 21mmHg using NCT (average of four readings), in the
presence of normal optic nerves and full visual fields will undergo immediate contact tonometry.
There are four possible outcomes:
1) IOP within the normal range – No further action is required
2) IOP within the range 22 – 31mmHg - Applanation should be repeated on a different day at a
different time of day
3) Inter-ocular IOP differs by >5mmHg - Applanation should be repeated on a different day at a
different time of day
4) IOP > 31mmHg – Patient should be referred to the HES without repeat
Where repeated measurements are not practicable (e.g. during a domiciliary visit) the optometrist
may consider referral on a single measurement.
There are three possible outcomes of the repeat measure:
1) IOP within normal limits – No further action required
2) IOP confirmed to be above 21 mmg – Refer as per joint Royal College of Ophthalmologists /
College of Optometrists guidelines (see below)
3) IOP shows consistent inter ocular difference of 5mmHg or more - Consider referral where no
other reasonable explanation exists (eg monocular intraocular lens implant)
Please note. Studies show that diurnal IOP variation of 6 mmHg or more warrants referral for further
investigation
The joint Royal College of Ophthalmologists / College of Optometrists guidelines suggests that
optometrists might consider not referring patients with normal optic nerves and visual field who are
aged 65 – 79 years with IOP’s 22 – 24mmHg and patients with normal optic nerves and visual fields
who are aged 80+ with IOP 22-25mmHg. These patients are not in any group specifically covered
within the NICE guidelines. The most appropriate way to deal with them is to make the assumption
that the Colleges advice constitutes the establishment of a ‘management plan’ as per paragraph 1.5.6
of NICE CG85 and monitor these patients as having diagnosed ocular hypertension in practice on an
annual basis.
Fee
The fee will be £20 for the initial assessment and a further £20 for up to one repeat if needed.
Accreditation
No accreditation is expected as contact applanation tonometry is a ‘core competency’ with which all
optometrists should be familiar.
No minimum period of registration required.
Equipment
Both Goldmann tonometry and Perkins handheld tonometry is acceptable for this scheme though slit
lamp mounted Goldmann tonometry is considered to be the gold standard.