Diagnostic Accuracy and Reproducibility of Tendency Oriented Perimetry in Glaucoma

Abstract

Purpose To evaluate the diagnostic capability of tendency oriented perimetry (TOP) in glaucoma. Methods A): The diagnostic accuracy of mean defect (MD), square-root of the loss variance (sLV), and number of pathologic points (NPP) was calculated in 295 normal and 414 glaucoma eyes (179 early, 112 moderate, and 123 advanced) examined with TOP. B): Threshold fluctuation (F) and its relationship with the loss variance (LV) was measured in 34 normal and 33 glaucoma eyes (mean MD=3 dB; SD=3.9) for TOP and for full-threshold perimetry (FT). C): Twenty-eight eyes with stable glaucoma (mean MD=9.5 dB; SD=7.2) were examined six times to quantify LV error. D): TOP and FT were tested with the simulation program PeriSim using different behavior models. Results A): The best diagnostic index in early glaucoma (MD<6dB) was sLV(specificity=90.2%, sensitivity=84.9). The three indices had similar precision in moderate and severe glaucoma. B): Threshold fluctuation and sLV were better correlated in TOP (r=0.72, p<0.01) than in FT (r=0.62, p<0.01). For normal subjects, in FT the incidence of F<2 dB was 8.82% and sLV<1.5 dB 5.88%. The same frequencies in TOP were 67.65% and 55.88%. C): Averaging six examinations reduced the sLV value by 22%. D): The threshold estimation error increased 1 dB in TOP in relation to FT for the same patient's behavior, but the error in TOP was lower than in FT when the worst behavior was modeled. Conclusions TOP is a good discriminator between glaucoma and normality. Perimetry results overestimate the real sLV value. TOP's high diagnostic ability is probably associated to the algorithm design and to less contaminating influences during the examination.

Risk Factors for Central Visual Field Progression in Myopic Patients with Primary Open-Angle Glaucoma

“…18,19 All individual sensitivity values at each test location within the central 10° eld and outside the central 10° eld were averaged to obtain the central mean sensitivity (MS) and peripheral MS, respectively. The MS of the global, central 10°, superior central 10°, and inferior central 10° regions were also collected.The rates of VF progression are expressed as slopes in dB/year, calculated using linear regression analysis.…”

La frecuencia topográfica global de los defectos en el glaucoma: En recuerdo de Erich Seidel (1882-1948)

“…A continuación, separamos en un primer grupo los casos que presentaban un defecto medio (MD) inferior a 3 dB, acompañado de una baja irregularidad (raíz cuadrada de la varianza de pérdida sLV < 2.66 dB) 11 , compuesto principalmente por hipertensos oculares (OHT) y casos sospechosos de glaucoma (7.704 casos). Los cuatro grupos restantes se formaron atendiendo a que el valor de MD fuese inferior a 3 dB (1.354 casos), se situase entre 3 y 6 dB (3.603 casos), entre 6 y 12 dB (5.450 casos) o fuese mayor de 12 dB (286 casos).…”