Clinical Publications

TRITON

Optic Nerve Head Changes After Intraocular Pressure-Lowering Glaucoma Surgeries Using Optical Coherence Tomography

AUTHORS:

Silveira V d’Azevedo, Lindenmeyer RL, Pakter HM, Skaat A, Lavinsky D, Oliveira M, Picceti E, Lavinsky J, de Arruda Mello PA, Lavinsky F.

PUBLICATION:

Journal of Glaucoma 32(9):p 756-761, September 2023. | DOI: 10.1097/IJG.0000000000002242

Study Purpose

To detect changes in the ONH with SS-OCT after IOP-lowering procedures.

Overview

Study Design

Prospective, longitudinal study

# of Eyes/
Patients

• 15 eyes of 12 glaucoma patients indicated for surgical intervention.

Study Device

DRI Triton Plus SS-OCT (Topcon, Tokyo, Japan)

Outcome Measures

• Mean and standard deviation of the hypotenuse of the optic nerve head cup (HOC). • HOC parameters of length and depth. • Change in the BMO-to-BMO (Bruch Membrane Opening) diameter. • Time points: baseline, PO1 (up to 7 days postoperatively), and PO2 (between 30-90 days postoperatively)

Results

The measurements were obtained manually by a single trained examiner (V.A.S.) using the caliper function of the device’s commercially available software (IMAGEnet 6).
Mean HOC decreased significantly after the IOP-lowering procedures, markedly between the preoperative period and PO1: 1002.21 µm–921.13 µm, (95% CI:-135.104 to-27.067, P= 0.001).
There was no significant change in any parameter between PO1 and PO2 (P= 1.0).
The mean HOC depth and length in the 5 central B-scans, and the horizontal BMO to-BMO extension also decreased significantly.

IMOvifa reduced measurement time by

39%

Conclusions

• The study suggests that small postoperative changes in the ONH of patients with glaucoma can be measured by very precise methods, such as OCT, even if they are not visible by direct fundoscopic evaluation of the optic nerve. • Significant structural changes in the ONH, mainly between the preoperative and early post-operative periods, were observed and measured. This suggests that decompression has a mechanical effect during the immediate post operative period. • The authors noted that the study has some limitations. First, the patient sample was small; recruitment was limited due to coronavirus disease pandemic protocols. Second, most of the participants had advanced glaucoma and third, the examiner was not masked for the sequence of visits. However, the measurements were performed objectively by an expert-trained examiner simulating the clinical setting. Finally, the follow up was short (3m), longer longitudinal studies are necessary.