We congratulate Ong et al. on their interesting article addressing greener intravitreal injection (IVI) services [1]. The article explores strategies to reduce the environmental impact of building energy and water usage, personal travel, manufacturing, procurement and waste management. We would like to highlight the role of the Delphi process for reducing carbon footprints of IVI services based on our experiences at an NHS teaching hospital.

The Delphi process has been used to improve the sustainability of local cataract services and involves the following steps [2]:

1.

Collect ideas by email from multi-disciplinary team members about improving the sustainability of local services.

2.

De-duplicate, anonymise and group ideas into themes.

3.

Invite staff to a face-to-face meeting to discuss each idea and discard unrealistic ideas.

4.

Collate the refined ideas into an online poll and ask staff to rank them.

5.

Form a team to implement the highest ranked ideas.

6.

Estimate the financial savings and carbon or waste savings before and after implementation.