Central field perimetry of discriminated targets: I. Results for normal individuals using high-contrast targets

Abstract

Purpose A new perimetry method is described to evaluate central vision under multiple hue, illumination, and contrast conditions; results are described for normal individuals using high-contrast targets. Methods For 70 normal eyes of individuals with varying age, the ETDRS chart acuity was determined as well as discriminated target perimetry using high-contrast targets presented for 250 ms at locations up to 101 eccentricity. Retesting was performed to evaluate for learning and repeatability for the thresholded acuity at each eccentricity. Results The ETDRS acuity averaged 1.15 ± 0.37 arc min minimum angle of resolution (MAR) with best correction (20/23 equivalence). At fixation, the thresholded acuity for high-contrast targets paralleled the ETDRS acuity and averaged 1.75±0.85 arc min MAR (20/35 equivalence), and declined with increasing eccentricity in a linear fashion to 5.81 ± 3.97 arc min (20/116 equivalent) at 101 eccentricity. Linear regression showed Vmar ¼ 1.74 þ 0.330 * eccentricity in degrees (R 2 ¼ 0.966, Po0.0001). Testing time required B8-10 min per eye. Repeated testing showed only minimal learning experience at the most peripheral locations. The test-retest 95% confidence limits of difference measured 1.12 arc mins MAR at fixation (64% of the mean) and remained approximately the same proportion to the mean thresholded acuity outwards to 101 eccentricity. Conclusion The methodology seems rapid and reliable for measuring discriminatory visual function of optotype targets throughout the central 201 diameter visual field.

Visual Function Assessment in Simulated Real-Life Situations in HIV-Infected Subjects

“…Indeed, it is generally recognized that the ETDRS chart test poorly correlates with activities of daily living [14] (such as driving at night or playing sports outside), since it’s not time-dependent, and as it allows an evaluation of the BCVA only in a pre-determined single high-contrast glare environment. [15] If the widely used ETDRS chart test is poorly reliable in evaluating BCVA in other contrast or luminance conditions for normal eyes, this may be also worse for PLWH. Indeed, these patients have a poor low-contrast visual performance – even without any retinitis [2] – and can also have poor driving performance.…”

Photodynamische Therapie mit halber Verteporfin-Dosis zur Behandlung der Chorioretinopathia Centralis Serosa

“…Außerdem wurde die automatisierte Messung der zentralen makulären Netzhautdicke mittels SD-OCT und eine Autofluoreszenz mit anschließender Fluoresceinangiografie durchgeführt. Die Kontrastsehschärfe wurde mittels Central Vision Analyzer (Vimetrics, Media, PA) bestimmt[10]. Es wurden6 Kontraststufen (M1, 2, 3 und G1, 2, 3) bei verschiedenen Lichtstärken untersucht und für jede Kontraststärke ein Dezimalvisus errechnet.…”

Visual function assessment in simulated real-life situations in patients with age-related macular degeneration compared to normal subjects

“…For these reasons, other investigators have suggested that these chart tests are not a useful determination of vision in other contrast or luminance environments, and those measurements are poorly correlated with daily living activities 8,9 that require the patient to assess visual stimuli in multiple lighting, contrast, or glare conditions against a varied background color or luminance. 7 Also, many common daily activities require an individual to react to a visual stimulus with limited time or information. 7,10 Testing of multiple aspects of patients' visual function (such as contrast sensitivity, luminance adaption, color perception, and reading speed) currently must be performed with separate tests and scoring methods.…”

“…7 Also, many common daily activities require an individual to react to a visual stimulus with limited time or information. 7,10 Testing of multiple aspects of patients' visual function (such as contrast sensitivity, luminance adaption, color perception, and reading speed) currently must be performed with separate tests and scoring methods. Recently, the Central Vision Analyzer (CVA; Visoptics, LLC, Mechanicsburg, PA, USA) has been introduced and approved by the Food and Drug Administration as a new interactive computer program to perform a comprehensive analysis of the central visual acuity under conditions that simulate environments of real-world activities that are often reported as visually stressful, such as those encountered under mesopic, lighting, or glare photopic conditions.…”

“…5 In addition, well-known issues of scoring the Snellen chart test and the ETDRS test are also present: means of calculating BCVA scores may vary between examiners, as patients are often able to read only some letters but from multiple lines. 6,7 Moreover, these chart tests use high-contrast black letters against an unchanging white background of one luminance in the moderate photopic environment of the examination office. For these reasons, other investigators have suggested that these chart tests are not a useful determination of vision in other contrast or luminance environments, and those measurements are poorly correlated with daily living activities 8,9 that require the patient to assess visual stimuli in multiple lighting, contrast, or glare conditions against a varied background color or luminance.…”