Study finds, Repeatability and inter-observer variation of c
A Study was conducted to estimate the repeatability and inter-observer variation of choroidal thickness measurements in myopic children aged 7–14 years using swept-source optical coherence tomography (SS-OCT).

In this Study, 39 children were enrolled. Optical correction was single-vision spectacles (SVS) or orthokeratology lenses (OKL). Three repeated 7 × 7 mm 3-dimensional SS-OCT macula scans and three repeated 9 mm SS-OCT line scans were collected for each child using a DRI OCT Triton. Choroidal thickness was measured using three different methods: line scan method 1 (LM1), line scan method 2 (LM2) and 3D macula scan method (3DM). Segmentation was adjusted if needed. Coefficients of repeatability (CR) and limits of agreement (LoA) were calculated.

--The CRs ranged from 13.4 to 23.9 microm, 14.5 to 26.2 microm and 5.2 to 10.7 microm for LM1, LM2 and 3DM, respectively.

--The LoA ranged from 22.9 to +31.5 microµm, 23.3 to +32.2 microm and 10.2 to +12.4 microm for LM1, LM2 and 3DM, respectively.

--Segmentation was adjusted in most scans (63%–92%).

Finally, in this paediatric population, 3DM was the most repeatable approach. It produced a 10.7 microm CR, an interval of confidence of 2.4 microm, making the minimum observable difference between the two 13.1 microm observations. The variation in the intramethod could explain the majority of inter-observer variations. The CR at group level did not increase the segmentation adjustment on 3D macula scans.