Clinical Publications

TRITON

Comparison of the Lamina Cribosa Measurements Obtained by Spectral-Domain and Swept-Source Optical Coherence Tomography

AUTHORS:

Cakmak S, Altan C, Topcu H, Arici M, Pasaoglu I, Basarir B, Solmaz B

PUBLICATION:

Current Eye Research 44:9, 968-974, 2019. DOI: 10.1080/02713683.2019.1604971

Study Purpose

To compare the lamina cribrosa (LC) measurements obtained by Spectral-Domain Optical Coherence Tomography (SD-OCT) and Swept-Source Optical Coherence Tomography (SS-OCT) in the same eye and we also investigate how the differences in measurement will change in the presence of pseudoexfoliation glaucoma (PEG)

Overview

Study Design

Cross-sectional comparative study

# of Eyes/
Patients

• 53 eyes for 30 patients included. Group 1 included 29 eyes from 15 healthy patients. Group 2 included 24 eyes from 15 patients with bilateral pseudoexfoliation glaucoma (PEG).

Study Device

DRI OCT Triton™ (Topcon, Tokyo, Japan)
SD-OCT Spectralis™ (Heidelberg Engineering)

Outcome Measures

• Peripapillary RNFL thickness. • Difference in Bruch’s membrane opening (BMO) distance between devices. • Lamina cribrosa (LC) depth and thickness, cup to disk (C/D) ratio.

Results

The difference between the mean BMO measured by SD-OCT (1504.7 ± 154.2 μm) and by SS-OCT (1568.6 ± 193.3 μm) was statistically significant (p = .009).
The difference between LC depth and LC thickness measurements between two OCT devices were not statistically significant (Table).
The differences of the parameters measured by two devices were compared between two groups, there was no significant difference between groups in terms of difference of LC depth and difference of LC thickness; a significant difference was found in difference of BMO (106.6 ± 175.2 μm in healthy group vs 12.4 ± 153.8 μm in PEG group; p = .045).
There was a negative correlation between the difference of SS-OCT and SD-OCT BMO measurements and the cup/disc ratio (p = .007). Another negative correlation was observed between the difference of measurements of LC depth with two OCT devices and IOP (p = .015).
There was a positive correlation with C/D ratio and BMO via SS-OCT , LC depth via both SS- and SD-OCT; negative correlation with C/D ratio and LC thickness via SS-OCT (p < .05, for each). There was a positive correlation between the difference of SS OCT and SD-OCT BMO measurements and the RNFL thickness (p = .04).

IMOvifa reduced measurement time by

39%

Conclusions

• SS-OCT helps provide a clearer image of LC and promises to enable correct measurement of LC itself. • As the C/D ratio increases, the difference between the BMO length measured by two devices decreases. This indicates that as the C/D ratio increases, the measurement qualities become more similar and supports the theory that sensitive measurements such as SS-OCT can be obtained with SD-OCT in glaucomatous damaged eyes. Also, this is supported by the positive correlation between BMO measurements via SD-OCT and C/D ratio. • Screening for glaucoma in especially risky eyes and also glaucoma progression follow-up with ONH parameters should be done using the same OCT device