Purchase this article with an account.
Evan Wong, Ian Constable, Fred Chen; Test-retest variability of microperimetry in patients with type 2 idiopathic macular telangiectasia. Invest. Ophthalmol. Vis. Sci. 2013;54(15):3603.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To determine the test-retest variability of 2 microperimeters, the Nidek MP-1S and the CenterVue MAIA, in patients with type 2 idiopathic macular telangiectasia (MacTel).
In this prospective study, 13 patients with MacTel were enrolled. Each patient underwent microperimetry on 3 separate visits, with identical test strategies on both devices in a randomised order. SD-OCT images were obtained on each occasion. Test-retest variability for mean retinal sensitivity (MRS), temporal-wedge sensitivity (TWS) and central-point sensitivity (CPS) were analyzed by calculating the 95% coefficients of repeatability (CR).
Mean (SD) age was 60.0 (9.7) years. There was a statistically significant difference in MRS for the MAIA and the MP-1S across the 3 sessions, χ2 (2) < 0.01 for both devices (Friedman’s ANOVA). There was a statistically significant difference in TWS for both devices, χ2 (2) = 0.014 and 0.001 respectively. There was a statistically significant difference in CPS for the MAIA, χ2 (2) = 0.01, but not for the MP-1S, χ2 (2) = 0.90. CR of MRS for the MAIA and MP-1S was 5.5 dB (95% CI 4.0, 7.0) and 4.0 dB (95% CI 2.9, 5.1) respectively. CR of TWS for the MAIA and MP-1S was 7.7 dB (95% CI 5.6, 11.8) and 5.0 dB (95% CI 3.6, 6.3) respectively. CR of CPS for the MAIA and MP-1S was 9.7 dB (95% CI 7.1, 12.3) and 5.9 dB (95% CI 4.3, 7.5) respectively. Sensitivity analysis was performed by excluding data from visit 1, and cases 4 and 10, which displayed prolonged learning effect. This resulted in CR of MRS for the MAIA and MP-1S of 1.8 dB (95% CI 1.1, 2.5) and 1.6 dB (95% CI 1.2, 2.0). CR of TWS of 4.7 dB (95% CI 2.8, 6.6) and 1.6 dB (95% CI 1.2, 2.0) respectively and CR of CPS 4.4 dB (95% CI 2.6, 6.2) and 6.4 dB (95% CI 3.8, 9.0) respectively.
We recommend discarding the first test and using the second test as a baseline. For the MP-1S, the CR for MRS and TWS was lowest at 1.6 dB. For the MAIA, the CR for MRS was the lowest at 1.8 dB. MRS may be used to detect change in retinal sensitivity, and a change of 2.5 dB and 2.0 dB (upper limits of the 95% CI of CR) exceeds test-retest variability in the MAIA and MP-1S respectively. A change of 2.0 dB in TWS in the MP-1S also exceeds test-retest variability and provides further spatial information in this cohort.
This PDF is available to Subscribers Only