OCT angiography can detect microvascular changes predictive of normal-tension glaucoma

A study was conducted to investigate the contribution of vessel parameters to identify normal tension glaucoma (NTG) suspects at risk of normal tension glaucoma development. It was a multicenter prospective cohort study.

A total of 307 eyes of 307 normal tension glaucoma suspects having intraocular pressure within the normal range; a suspicious optic disc, but without definite localized retinal nerve fiber layer (RNFL) defects; and a normal visual field (VF).

To measure laminar vessel density (VD), the vessel density was measured in the intradiscal region from images of the deep vascular layers of optical coherence tomography angiography (OCT-A). Conversion to normal tension glaucoma was defined either by a new localized RNFL defect in the superotemporal or inferotemporal region, or the presence of a glaucomatous visual field defect on two consecutive tests according to the pattern standard deviation plots.

The Results of the study are:

• In total, 73 (23.8%) of the 307 normal tension glaucoma suspects converted to normal tension glaucoma during the follow-up period of 59.84 ± 12.44 months.
• The detection rate of microvasculature dropout (MvD) was significantly higher in normal tension glaucoma suspects who progressed to normal tension glaucoma (50.7%) than in those who did not
• The macular deep vessel density and laminar deep vessel density were significantly lower in normal tension glaucoma suspects who progressed to normal tension glaucoma.
• The presence of MvD and lower laminar deep vessel density were significantly associated with normal tension glaucoma conversion.

Thus, Normal tension glaucoma suspects with baseline MvD or a lower laminar deep vessel density on OCT-A had a higher risk of conversion.

Reference:

Younhea Jung et al. Microvasculature Dropout and Development of Normal Tension Glaucoma in Glaucoma Suspects: The Normal Tension Glaucoma Suspect Cohort Study. Published:August 03, 2022DOI:https://doi.org/10.1016/j.ajo.2022.07.020

Keywords:

Optical, coherence, tomography, angiography, detect, microvascular, changes, predictive, normal-tension, glaucoma, American Journal of Ophthalmology, Glaucoma, Glaucoma suspect, Microvasculature dropout, Optical, Coherence, Tomography Angiography, Younhea Jung, Hae-Young Lopilly Park, Heejong Shin, Si Eun Oh, Seong Ah Kim, Ji-Young Lee, Da Young Shin, Soo Ji Jeon, Yong-Chan Kim, Hye-Young Shin, Jin A Choi, Na Young Lee, Chan Kee Park