New techniques: blue/yellow perimetry--HRP(10').
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Biomedical subjects
Publications and source records attributed to G Corallo.
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PURPOSE: To quantify the quality of vision achieved with multifocal and bifocal contact lenses. METHODS: We analyzed differential light sensitivity by computerized automatic perimetry in 21 patients wearing monofocal soft contact lenses (group 1, controls) and multifocal and bifocal contact lenses (groups 2 and 3, respectively). Seven patients each were fitted with multifocal or bifocal contact lenses; seven patients were without contact lenses (without correction for testing the visual periphery and with near-vision correction using monofocal contact lens for testing the central 30 degrees of vision). The type of correction was randomly changed in a crossover fashion so that each eye was examined at different times with different corrections. Humphrey 640 VFA computerized automated perimetry was used to test visual fields at baseline, 45 days, and 3, 4.5, and 6 months. RESULTS: A statistically significant difference was found between the global sensitivities (GS) of the central visual field in patients with near-vision monofocal contact lenses and with bifocal contact lenses (P=0.0273) and between the GS of the central visual fields with multifocal contact lenses and with bifocal contact lenses (P=0.0261). In both cases, the GS were significantly reduced with bifocal contact lenses (total GS: group 1, 11256 dB (Decibels); group 2, 11154 dB; group 3, 10679 dB). CONCLUSIONS: The results indicate that there is reduced differential light sensitivity in the central 30 deg of the visual field with bifocal contact lenses compared with multifocal contact lenses and monofocal contact lenses (controls).
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.
PURPOSE: To evaluate the correlation between computerised visual field testing and optic disc morphometric parameters (rim area, rim/disc area ratio, cup/disc area ratio and optic disc surface smoothness (ODSS)) in the follow-up of a group of patients affected by primary open angle glaucoma (POAG). METHODS: Reliable automated perimetry (Humphrey 640 VFA, central 30-2 threshold program) was performed at T0 (the enrollment time), T1 (after 6 +/- 1 months; range 5-7 months), T2 (12 +/- 1 months), T3 (18 +/- 1 months), and T4 (the end of the follow-up period: 24 +/- 2 months) in one eye randomly chosen from each of 30 POAG patients. Computerised optic disc analysis (IMAGEnet X Rev-3-51b, Topcon Europe, The Netherlands) was performed at T0 and T4. To evaluate the correlation between morphometric parameters and computerised visual field testing, the stability or worsening of visual field test was evaluated by means of 'Mean Deviation linear regression analysis' (STATPAC 2 software); that of morphometric parameters was studied using their coefficients of variation. A rank of '0' was assigned to stability and a rank of '1' to worsening. The Spearman rank correlation coefficient was used to evaluate statistically the correlations between visual field analysis and morphometric parameters. Furthermore kappa statistic was used to evaluate the agreement of morphometric parameter changes with visual field progression analysis. RESULTS: According to the MD slope regression analysis, in 18 patients the visual fields were stable while in 12 they were worsening during the follow-up period. In 86.65% of patients (n = 26) the morphometric parameter ODSS and visual field analysis were concordant (p < 0.0001). In 80% of patients (n = 24) the cup/disc area ratio and visual field analysis were concordant (p < 0.001). The other morphometric parameters (rim area, rim/dics area ratio) were less correlated with visual field analysis than ODSS (p < 0.05). The agreement of visual field analysis with all the morphometric parameters was good (kappa = 0.690, 95% confidence interval (CI) of kappa = 0.589-0.790). The agreement of visual field analysis with ODSS and cup/disc area (kappa = 0.688; 95% CI = 0.511-0.864) was better than the agreement of visual field analysis with rim area and rim/disc area ratio (kappa = 0.438; 95% CI = 0.260-0.655). CONCLUSION: Analysis of the progression of visual field damage and optic nerve head morphometric parameters should both be taken into account in glaucoma follow-up. Among the morphometric parameters evaluated by means of Topcon IMAGEnet, ODSS and (to a lesser extent) the cup/disc ratio should have the greatest weight.
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PURPOSE: To define a method for early detection of progressive visual field loss, based on monitoring the "healthy" component of the visual field, in glaucoma patients whose perimetric findings show the co-existence of deep scotomata and normal sensitivity areas. METHODS: We reviewed all the "central 30-2 threshold tests" stored in the oldest of our Humphrey perimeters (a 640 VFA model, in use at the Glaucoma Service of the University Eye Clinic of Genoa since 1986). Only the perimetric findings of glaucoma patients with pure, deep, localized defects were collected for this study. In accordance with several inclusion criteria, we could select only 12 series of consecutive examinations (12 eyes of 12 patients). Each series included 12 to 20 examinations and the observation period ranged from 6 years 2 months to 9 years 4 months. Some pre-defined criteria made it possible to separate the defective component of the visual field from the "healthy" one. Then two independent "mean deviations" were calculated, one related to the "healthy" area and one to the defective one. RESULTS: The mean deviation related to the "healthy" component of the visual field showed very little variation (0.6 to -1.3 dB) in the four series that had no increase in defects, even at the end of the observation period. However, in 7 of the 8 series with a tendency to worsen there was a small inter-test increase (-2.2 to -2.6 dB). This finding anticipated the enlargement of the scotomata, confirmed by subsequent examinations. Only in one series did the increase of the mean deviation related to the "healthy" area coincide in time with the real deterioration of the visual field, rather than anticipating it, but the inter-test interval had by chance been much longer than in the other series. The mean deviation related to the defective areas always showed very large changes in all the series, caused by the high variability of thresholds inside scotomata. This was the explanation for the large variations revealed by the "global" mean deviation too. CONCLUSIONS: Detecting progression is still one of the major problems in evaluating perimetric results. It might be easier to achieve this goal with a method for selectively monitoring light sensitivity inside the "healthy" areas of the visual field.
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.