Undiagnosed glaucoma is too common and detecting it at a rate that matches the reported population prevalence and eliminates preventable vision loss and blindness is a bold ambition, but one that optometrists should be working towards with passion and determination.
To date, we’ve been able to learn a lot about detecting undiagnosed glaucoma by collecting data and analysing and amending our detection protocols to impact this condition.
OCT
To measure the impact of systematic usage of OCT within Specsavers’ practices on the detection of glaucoma, at a macro-level, a comparison needed to be made to identify the difference in detection rates between practices using OCT and practices using DRP (the comparison group).
Data needed to be collected uniformly for both groups, with the facility to re-classify a practice when it had launched OCT as part of standard practice.
Referrals
Glaucoma referrals were measured through a systematic process for referring to ophthalmology that allowed for specific classification of glaucoma referrals that could be isolated to a practice location, or indeed, an individual optometrist.
This was enabled through the adoption of Oculo and the extraction of data based on specified parameters.
Glaucoma referral rates could then be compared to the known population prevalence of the disease to provide a benchmark for practices to understand their impact on the detection rate.
At a micro-level, more detail was required as reporting on referral rates is only half of the equation when proving a sustainable model for preventative eyecare. The rest relates to the incremental clinical activity that leads to a positive outcome for a patient.
Visual Fields
In addition to a comprehensive ocular health work up and the granular structural information provided by the OCT, another key intervention crucial for glaucoma detection in primary optometric practice is the visual field test.
OCT cannot be used in isolation, it must be considered with other risk factors and the results of visual fields. For the purposes of providing meaningful and relevant information for optometrists to direct their practice, a key metric in measuring impact was identified as the ‘percentage of patients who received a visual field’.
It was analysis of the large-scale dataset of glaucoma referrals and the relationship between this and the performance of visual fields, that provided evidence for a benchmark for visual field performance in practice.
Visual fields as a percentage of patients vs glaucoma referrals as a percentage of patients
