We appreciate the interest of Hudson et al in our work. Measurement of retinal thickness vs clinical retinal edema is indeed an area that needs consolidation and demonstration of reliability of the different novel techniques used.
A recent study from our group1 addresses this problem. We used the RTA to evaluate 25 eyes from patients with type 2 diabetes over a period of 12 months on 3 separate visits, 6 months apart. Of the 675 scanned areas (ie, 25 eyes × 3 visits × 9 fixating points), 101 areas (15%) were considered suspicious; 78 of these areas (12%) matched positively with detected increased retinal thickness, ie, they were possible false-positives. When monitoring for RTA optical cross-sections and RTA fundus image quality, the percentage of possible false-positives decreased to only 5%.
Bernardes R, Cunha-Vaz J. Interpretation of Objectively Acquired Retinal Thickness Values—Reply. Arch Ophthalmol. 2003;121(9):1344-1345. doi:10.1001/archopht.121.9.1343-a