The use of zonal analysis of peripapillary choroidal thickness in primary open-angle glaucoma

PURPOSE:
To evaluate automatic peripapillary choroidal thickness (PPCT) measurements in a wide area around the optic disc and various established zones in primary open-angle glaucoma (POAG) patients and age- and sex-matched healthy controls using a new swept-source optical coherence tomography (SS-OCT) device.

STUDY DESIGN:
Single center cross-sectional observational study.

METHODS:
A total of 135 POAG patients and 86 healthy subjects were consecutively enrolled. An optic disc 6.0 × 6.0 mm three-dimensional scan OD was obtained using the SS-OCT Triton.

A 26 × 26 cube-grid centered in the optic disc was generated to automatically measure choroidal thickness. Seven choroidal zones were established (superior temporal, central, and nasal; inferior temporal, central, and nasal, and the optic nerve head) and compared between healthy controls and POAG patients.

RESULTS:
PPCT was significantly thinner in the central superior, nasal superior, and nasal inferior zones of the POAG subjects. Choroidal thickness in the central superior zone was 124.61 ± 54.95 µm in POAG group vs 156.17 ± 80.89 µm in healthy controls (p = 0.029); in the nasal superior zone, 133.84 ± 58.89 µm in the POAG group vs 168.34 ± 73.45 µm in healthy controls (p = 0.012); and in the nasal inferior zone, 113.45 ± 49.93 µm in the POAG group vs 137.47 ± 65.96 µm in healthy controls (p = 0.049).

CONCLUSION:
Compared with healthy subjects, glaucoma patients present with peripapillary choroidal thinning, especially in the central superior, nasal superior, and nasal inferior zones. The new SS-OCT could be a useful tool to evaluate choroidal thinning, and it could be an additional support to facilitate glaucoma diagnosis.

CITATION  Jpn J Ophthalmol. 2018 Jan;62(1):41-47. doi: 10.1007/s10384-017-0538-5. Epub 2017 Oct 11