Assessment of the Effectiveness of Different Variants of Frequency Doubling Technology Perimetry in Monitoring the Glaucoma Process

Abstract

Purpose: To compare the diagnostic effectiveness of non-standard perimetry and standard automated perimetry (SAP) during earlystage monitoring of primary open-angle glaucoma (POAG).Patients and methods. The study involved 30 patients (46 eyes) with early-stage of POAG, aged 30 to 65 years (54.9 ± 1.3), who were under ongoing monitoring for 3 to 4 years (3.50 ± 0.68 years). All subjects, in addition to the standard ophthalmological examination, performed the threshold program “24-2” perimetry using the Humphrey II, the own modification of Frequency Doubling Technology (FDT) Perimetry, in the form of 2 threshold strategies: the wellknown “FDT-16” and the new “FDT-64”. The condition of the optic nerve head (ONH) was assessed using HRT 3 (Heidelberg Retina Tomograph, Germany) and OCT — Topcon 3D OCT- 2000 (TOPCON, Japan). During monitoring, RTVue FD-OCT (Optovue, USA) was additionally performed, evaluating the parameters of the retinal ganglion cell complex (GCC).Results. Regular follow-up, the implementation of the prescribed treatment contributed to the stabilization of glaucoma, as evidenced by the stability of the average MD index values according to all 3 threshold strategies, but reliably (p = 0.000) only according to SAP data. According to the criterion of the number of scotomas, there was a weakly expressed, but statistically significant negative dynamics for all the compared strategies. According to the results of the structural assessment of the ONH (the size of the excavation), a weakly pronounced negative dynamics was obtained in dynamics according to both HRT and OCT data. The average MD index values, the number of scotomas according to the three perimeter strategies and the excavation size based on HRT and OCT in patients with early-stage of POAG turned out to be stronger and more significant using the “FDT-16”, and the correlation characteristics with the results of “24-2” HFA II, “FDT-64” largely coincided.Conclusion. A reliable correlation between structural and functional parameters indicates the feasibility of using “FDT-64” in combination with SAP not only in for the diagnosis of the early-stage of glaucoma, but also in assessing its course. The sensitivity level of the results of “FDT-64” (100 %) compared to “FDT-16” (88 %) in patients with POAG was higher, therefore, “FDT-64” is advisable to use in complex diagnostic cases and in monitoring glaucoma.