Aim: To evaluate the long-term perimetric fluctuation (LF) in patients with different stages of glaucoma according to the Glaucoma Staging System 2 (GSS2). Methods: This multicentre retrospective study included 161 eyes of 161 stable glaucoma patients undergoing four visual-field tests (Humphrey SITA-Standard program over the central 24(degrees) or 30(degrees)) over a 2-year period. For each patient, the stage of the disease was classified according to GSS2. LF was then calculated as the mean of the standard deviations of point-to-point threshold sensitivities in the four repetitions. LF in GSS2 stages was compared using the t test. Results: LF progressively increased from stage 0 to stage 4, and then decreased at stage 5. Stage 4 had a peak of 3.19(plus or minus)0.94 dB, with statistically significant differences compared with all the other stages. The lowest LF (1.65(plus or minus)0.60 dB) was found for normal subjects, whereas similar data were found for borderline patients and those at stages 1 and 5 (2.09(plus or minus)0.58, 2.13(plus or minus)0.57 and 2.22(plus or minus)0.89 dB, respectively; p>0.13). Visual fields with generalised defects had a lower LF (1.90(plus or minus)0.81) than those with mixed (2.84(plus or minus)0.87, p=0.0003) and localised (2.6360.72, p=0.004) defects. Conclusions: In this study, the authors showed that the lower the visual-field defect, the lower was LF, except at stage 5 of GSS2. As test-retest changes exceeding LF could represent a sign of progression, the authors suggest that clinicians using this classification system calculate LF, in order to better differentiate true progression from variability.
P. Fogagnolo. Eye Clinic, San Paolo Hospital, Via di Rudini' 8, Milan 20142, Italy. firstname.lastname@example.org
6.6.2 Automated (Part of: 6 Clinical examination methods > 6.6 Visual field examination and other visual function tests)