Evaluation of the New Compression-Perimeter Test Effectiveness in the Early Diagnosis of Glaucoma

Abstract

Purpose: To evaluate the effectiveness of a new modification of the vacuum-perimeter test (VPT) by V.V. Volkov in the early diagnosis of glaucoma in comparison with the results of the original test and its known modification — vacuum-compression automated test (VCAT) in an open comparative clinical research. Patients and Methods. The study involved 26 patients (47 eyes) (average age 52.9 ± 8.5 years) with suspected open-angle glaucoma (OAG). Patients were divided into three groups: 1-st — 19 eyes with preglaucoma, 2-nd — 18 eyes with the early stage of OAG, 3-rd — 10 eyes of five patients with unconfirmed glaucoma. The control group (4-th) included 20 eyes of 10 healthy people (average age 56.4 ± 4.4 years). Along with the standard ophthalmological examination, all patients underwent perimetry on Humphrey Visual Field Analyzer II 745i (Germany-USA), our modification of Frequency Doubling Technology (FDT) perimetry, evaluation of the optic nerve head (ONH) on Heidelberg Retina Tomograph (HRT 3, Germany) and three stress tests: VPT, VCAT and our modification — vacuum-contrast-frequency test (VCFT). VCFT was created on the base of FDT perimetry with the aim of increasing the sensitivity of the original test (VPT) for detection of preglaucoma through the use of non-standard stimulus and increasing the number of investigated points of central visual field. Results. According to the National classification (1975) the diagnosis of preglaucoma was determined on the basis of a positive result of at least one of three stress tests, taking into account the risk factors for the development of glaucoma in patients. The early stage of OAG was established on the base of International standards for structural and functional assessment of the ONH (2003). The specificity of all three compared stress tests was 100 %, which confirmed their negative results in all patients (10 eyes) from the 3-rd group. However, the sensitivity of VCFT (75 %) was significantly higher than VPT (21.05 %) and VCAT (21.05 %), which is due, we believe, to the specific nature of VCFT stimulus. Conclusion. According to the obtained data, the developed new modification of VPT — VCFT on the specificity of the results was not worse, and the sensitivity was better than the original VPT and VCAT in the diagnosis of preglaucoma. VCFT is quickly performed and comfortable for patients.

Keywords

• early diagnosis of glaucoma
• preglaucoma
• open-angle glaucoma
• stress test