Inter- and intra-observer agreement in the measurement of macular holes by optical coherence tomography

A full-thickness macular hole ("FTMH") is a foveal lesion caused by a defect in the full thickness of the neurosensory retina. Its diagnosis and the indication for surgical treatment take into account the measurement of the hole according to the tool provided by the OCT. This measurement can be performed by several ophthalmologists during the follow-up of a patient. The aim of this study is to find out whether there is intra-individual and inter-individual variability in these measurements.

Retrospective review of OCT b-scan images with a diagnosis of FTMH. Measurements of the minimum diameter of the FTMH were performed using the hand-held tool available on the DRI-Triton (Topcon, Japan) at 1:1 and 1:2 scales, on different days, by 2 retina specialists and 2 residents. These measurements were compared to assess inter-observer and intra-observer correspondence.

Thirty-four images were analysed. For intra-observer variability, a correlation index higher than 0.98 was obtained in all cases. For inter-observer variability, the intra-class correlation coefficient was 0.94 (95% CI: 0.91-0.97) for the 1:1 scale, and 0.94 (95% CI: 0.91-0.97) for the 1:2 scale.

OCT-measured AMEC size values are reproducible between ophthalmic specialists and residents and are independent of the imaging scale at which the measurement is made.