Defining stable glaucoma: a Delphi consensus survey of UK optometrists with a specialist interest in Glaucoma.

Abstract

Increasing demand on hospital services has led to the development of alternative community-based services, often run by optometrists for monitoring 'stable' and low-risk glaucoma patients. An online Delphi exercise was undertaken to derive a consensus definition of 'stable glaucoma' amongst optometrists with a special interest in glaucoma. Participants were asked to score their agreement for various clinical parameters. Results from each round were used to inform subsequent rounds. 31 optometrists participated in the study. 100%, 77%, and 68% completion rates were achieved over three rounds respectively. Consensus was reached for 7 parameters: Stability should be defined over a period of 36-48 months, summary measure Visual Field (VF), and/or Trend Analysis should be used to assess VF stability. Two or more decibel (dB) of change of VF mean deviation (MD) is considered unstable. Intraocular pressure (IOP) should be below a target defined by the patient's clinician or a fixed-percentage reduction compared to the presenting IOP. No treatment change during the stability assessment period is considered stable. Imaging with Ocular Coherence Topography Retinal Nerve Fibre Layer (OCT RNFL) assessment should be used to define glaucoma stability. Overview by a glaucoma consultant was considered important for glaucoma monitoring schemes. This Delphi exercise has generated a consensus definition for glaucoma stability by UK Optometrists with a specialist interest in glaucoma. This consensus definition can be used to inform the selection of suitable patients from hospital services for transfer to monitoring in community-based 'stable' optometry run glaucoma clinics.