8/7/2019 O'Leary Artes Nicolela Chauhan ARVO Poster 2011

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Rates of retinal nerve fibre layer thickness change from scanning laser polarimetry andtime-domain optical coherence tomography in glaucoma patients and control subjects

Program #4162

Author disclosure block: N. O'Leary, None; D.M. Hutchison, None; P.H. Artes, None; M.T. Nicolela, None; B.C. Chauhan, Heidelberg Engineering, F, Carl Zeiss Meditec, F.

Participants

Seventy-five glaucoma patients (Artes PH and Chauhan BC, Prog Retin Eye Res 2005) and 55control subjects.

To examine rates of change of retinal nerve fibre layer thickness (RNFLT) measurements inglaucoma patients and healthy, age-similar control subjects with:

- scanning laser polarimetry (SLP) with variable corneal compensation (VCC) and enhancedcorneal compensation (ECC)

- time-domain optical coherence tomography (OCT)

To assess longitudinal RNFLT variability, the potential sources of variability and the power to detectRNFLT change with each imaging modality.

Grant MOP-11357 from the Canadian Institutes of Health Research (BCC)

Results show a slow rate of RNFLT change in these glaucoma patients (mostly indistinguishable fromcontrols), possibly with most changes having occurred prior to study enrolment.

The significant difference in rates of change between glaucoma patients and controls in OCT wasmainly due to a spurious finding of increasing RNFL thickness in controls

Rates of change of TSS are strongly correlated with rates of RNFLT change in VCC but not in ECC.

Simple modelling based on measurement variability of these devices shows reasonable power of thesedevices to detect clinically meaningful RNFLT change.

Figure 2. Distributions of rates of RNFLT change in glaucoma patients for(a) VCC series, (b) ECC series and (c) OCT series and in control subjectsfor (d) VCC series (e) ECC series and (f) OCT series.

Figure 1. The study selection criteria for analysis ofscans and series for VCC, ECC and OCT imagingmodalities. Summary of number of eyes in eachgroup and median number of scans and length offollow-up for each imaging modality and group areshown.

Figure 5. Rates of RNFLT change and

corresponding rates of TSS change inboth glaucoma patients and controlsubjects for (a) VCC series and (b) ECCseries. Spearmans values for inpatients were -0.46 (p