Sector-based analysis of frequency doubling technology sensitivity and optic nerve head shape parameters.

PURPOSE: To evaluate which Heidelberg Retina Tomograph (HRT) parameter is the best predictor of frequency doubling technology (FDT) sensitivity by using a sector based analysis between FDT and optic nerve head shape parameters such as cup shape measure (CSM) and rim area (RA), which have been shown to have the best correlation with FDT indices among all the HRT parameters. METHODS: One eye was randomly chosen from 100 patients with primary open angle glaucoma (abnormal visual field and/or abnormal optic nerve and untreated intraocular pressure above 21 mm Hg). All the patients were examined with Humphrey field analyzer (HFA), program 24-2, SITA standard, FDT program C 20, and HRT. RA and CSM for the HRT analysis and mean deviation, pattern standard deviation, and the sensitivity of each tested point for the FDT test were considered in this study. All the parameters were calculated as both global and sector measurements. Findings were analyzed using Pearson's correlation coefficient and linear regression model. RESULTS: Significant (p<0.001) correlation was found between FDT indices and HRT RA and CSM. Significant (p<0.001) sector correlation was found between FDT sensitivity and RA and CSM, but when a linear regression model was applied, RA was the most predictive parameter of FDT. Temporal CSM was more strongly correlated to FDT fovea sensitivity than temporal RA. Furthermore, sector HRT parameters were better correlated to HFA than to FDT. CONCLUSIONS: In this glaucomatous group, cup shape measure and RA were significantly correlated to FDT indices. RA was more predictive of FDT abnormality than CSM in all the considered sectors except in the temporal one. However, HFA was a stronger predictor of HRT parameters than FDT.

Conventional perimetry, short-wavelength automated perimetry, frequency-doubling technology, and visual evoked potentials in the assessment of patients with multiple sclerosis.

PURPOSE: To evaluate the diagnostic power of conventional, achromatic, automated perimetry (CAP), short-wavelength automated perimetry (SWAP), frequency-doubling technology (FDT) perimetry, and visual evoked potentials (VEP) in a group of patients with multiple sclerosis (MS) with or without a history of optic neuritis. METHODS: Thirty eyes of 15 patients (5 male, 10 female, average age 38+/-7 years) with confirmed diagnosis of MS underwent CAP, SWAP (Humphrey 750-II VFA, program central 30-2, full-threshold strategy), FDT perimetry (program N-30), and pattern VEPs. Sixteen eyes (53.3%) had no history of ocular involvement and a negative ophthalmologic examination. They were matched with a control group of 10 healthy volunteers (4 male, 6 female, average age 31+/-10 years). The mean deviation (MD) and the pattern standard deviation (PSD) of the two groups were compared (t-test). Fourteen eyes (46.7%) had, on the contrary, a history of optic neuritis. Inside this group, the MD and the PSD of the three techniques were correlated (Spearman's rank test), in order to investigate whether any significant differences might be revealed by these techniques in pointing out the total amount of visual field damage. RESULTS: When comparing MS patients without signs or symptoms of ocular involvement and a control group, no significant differences were found for CAP MD, CAP PSD, and FDT PSD. Significant differences were found, on the contrary, for SWAP MD (p=0.0014), SWAP PSD (p=0.0001), and FDT MD (p=0.0001). When considering the MD and the PSD of the three techniques in the group of MS patients who had a history of optic neuritis, a significant correlation was found only between CAP MD and SWAP MD (r=0.0057), with a tendency by SWAP to reveal a higher rate of visual field loss. The other correlations were not significant. According to predefined criteria, the group of asymptomatic subjects had abnormal CAP in 1 eye (6.25%), abnormal SWAP in 9 (56.2%), abnormal FDT in 11 (68.7%), and abnormal VEPs in 7 (43.7%). The combined use of all techniques allowed us to identify silent optic nerve impairment in 15 (93.7%) eyes. CONCLUSIONS: Short-wavelength automated perimetry and FDT perimetry are two non-conventional perimetric techniques that were mainly developed for the early detection of glaucomatous damage. The results of this study demonstrate their efficacy also in detecting early visual field deficits in MS patients without clinical signs of optic neuropathy. Frequency doubling perimetry, in particular, proved to be an easy, fast, and sensitive technique in the assessment of patients with MS. Our results also suggest that subclinical visual involvement in MS can be better diagnosed using multiple (neurophysiologic and psychophysical) tests.

Deficit-undamaged visual field area monitoring in glaucomatous patients with advanced perimetric damage: its usefulness.

This report contains the observations of the authors on the behaviour with time of the visual field areas (VF) which appear undamaged by deficit within the perimetric findings where at the same time there is advanced glaucomatous damage. A retrospective study has been made on the records of a Humphrey perimeter 640 VFA relating to glaucomatous patients with these perimetric characteristics in whom at least 12 examinations (programme "Central 30-2 threshold test") had been made and who, for a good part of the period of observation at least, had recorded a topographic stability of the deficits. There were found 12 series of examinations responding to the required necessities. The analysis of the findings used a method that separated from the global mean deviation (MD) that part concerning the pathological area and that referring to the "healthy" area of the visual field (VF). In 7 of the 8 cases where, at a certain point in the follow-up, there became evident a trend towards worsening, there was also a significant increase in the MD of the undamaged, which occurred before the deterioration of the "healthy" area became evident by the appearance of "probability symbols" in the "total deviation" map. In the 4 cases where there was stability with time, the MD values relating to the undamaged area of the VF were quite constant with time.