As reported in the 2019/20 edition of the Specsavers Eye Health Report (pages 69-72), the diagnostic sensitivity of OCT and the additional clinical information it provides enables optometrists to detect macular oedema at improved levels due to the enhanced visualisation of retinal structures. This is important as optometry looks to technological advancements to assist with detection of all sight-threatening disease.

Coinciding with an increase in patient optometric appointments and referral rates as well as the rollout of OCT, Specsavers practices have seen referrals for macular oedema increase five-fold from 13% of diabetes referrals in 2017 (505 patients) to 27.8% in 2020 (2,841 patients).

While the most common demographic for diabetes referrals are those over 65 years old, it is interesting to note that macular oedema is most commonly detected in those aged 40-64. This working age detection trend highlights the impact of OCT on detecting early stage disease and gives further evidence to support the standardised utilisation of OCT on all patients.

Specsavers is also on a journey to classifying the patients receiving referrals for diabetes eye disease so that more information can be learnt, and clinical practices can be enhanced further.

When optometrists refer patients with diabetes, they can, through Oculo, electronically classify the severity of retinopathy – i.e., if the detection is proliferative diabetic retinopathy, severe non-proliferative diabetic retinopathy, mild-moderate non-proliferative diabetic retinopathy or minimal, as well as the presence of centre-involving or non-centre involving macular oedema

Of those classified macular oedema detections, the relative proportions roughly correlate with the data published in Diabetes Care here and the National Eye Health Survey here. The sight threatening presentations that require immediate attention, including proliferative and severe non-proliferative diabetic retinopathy macular oedema make up 3.5% (an average of 97 patients per quarter nationally) and 5.5% (an average of 149 patients per quarter nationally) of patients referred for diabetic retinopathy. Patients with centre-involving macular oedema make up 18.9% of referrals (479 patients per quarter nationally).

The data also highlights the occurrence of macular oedema detections alongside other classifications, with the most common being detected alongside mild to moderate non-proliferative diabetic retinopathy. This is important to identify because while it is known there are correlations between patients with proliferative retinopathy and macular oedema, the mild to moderate links aren’t as widely known. As many optometrists monitor patients with mild to moderate disease themselves, they must be alert to the risk of macular oedema as well. If centre-involving macular oedema is present, the patient’s sight may be at risk and specialist intervention is likely needed.