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J Caprioli

Publications and source records attributed to J Caprioli.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Indications for stimulus 3 and 5 in automatic perimetry. Preliminary results].

PURPOSE: Goldmann stimulus size 3 and 5 were studied with automated perimetry in glaucoma patients to help develop specific guidelines for their use. METHODS: We examined 49 eyes of 49 glaucoma patients with both stimulus sizes 3 and 5 with Program G1 (all phases) of the Octopus 500 Perimeter. Fields were preformed sequentially, in random order, at the same sitting. RESULTS: The means of the indices for stimulus size 3 (+/- = standard deviation) were: Mean sensitivity 18.8 +/- 4.7 dB; loss variance 45.0 +/- 42.0 dB2; short-term fluctuation 2.1 +/- 0.45 dB. With stimulus size 5, mean sensitivity increased (Wilcoxon: p < 0.0005) by 8.1 +/- 1.7 dB, and short-term fluctuation decreased (Wilcoxon: p < 0.0005) by 0.3 +/- 0.6 dB. Scotomas measured with stimulus size 5 were shallower than with stimulus size 3, i.e., the pattern of visual field defects was better represented by stimulus size 3 in 13 eyes. Stimulus size 5 was preferred in 14 eyes because more information was available in the area of absolute scotomas. In 6 eyes, deep scotomas within 4 degrees of fixation were seriously underestimated with the larger stimulus. CONCLUSIONS: Stimulus size 5 should be used if more than 10% of test locations have absolute scotomas or the mean sensitivity falls below 15 dB with stimulus size 3. Complementary central fields with stimulus size 3 fields should be used when evaluation of the central field shows relative scotomas with either stimulus.

Aged↗
PubMed1993

An evaluation of clusters in the glaucomatous visual field.

We used a statistical cluster analysis to analyze patterns of loss in 76 visual fields with typical glaucomatous defects to identify natural groupings of test locations in the visual field. Eleven clusters in the Octopus Program G1 (Interzeag, Inc., Northboro, Massachusetts) visual field were thus defined. In a separate population of 70 early glaucomatous and 70 age-matched normal visual fields, the local mean defects within these clusters and the global mean defect were calculated to assess their relative abilities to discriminate between the two groups. The 11 clustered mean defects collectively had a sensitivity of 90% and a specificity of 93%; the global mean defect had a sensitivity of 81% and a specificity of 91%. Additionally, we examined the long-term fluctuation clusters of test locations compared to the long-term fluctuation of individual test locations. Four hundred ten visual fields of 93 clinically stable eyes of 67 patients with glaucoma, as well as 210 visual fields of 105 eyes of 105 normal subjects were studied. In the stable glaucoma group, mean fluctuation of clustered test locations was 3.5 dB2, and mean fluctuation of individual test locations was 7.0 dB2. In the normal group, the respective values were 0.6 dB2 and 1.8 dB2. Cluster analysis was effective in detecting localized loss and in dampening long-term fluctuation. We studied the use of clusters in distinguishing normal from glaucomatous as well as stable from deteriorating visual fields.

Adult↗
PubMed1993

Progression of disc and field damage in early glaucoma.

To assess the temporal relationship between visual field progression and optic disc deterioration in early glaucoma, we studied 15 patients with unilateral visual field loss from primary open angle glaucoma. Planimetric optic disc measurements were compared with automated static threshold perimetry during a mean follow-up of 6.1 years. Eight (53%) of 15 eyes with an initially normal visual field showed progression of the disc; six of these eyes did not develop field abnormalities. The mean rates of rim-area loss were 1.7%/y in eyes with initially normal fields and 2.1%/y in eyes with initial field loss. The mean rate of visual field deterioration (change in corrected loss variance) was lower in the eyes with an initially normal field (0.3 dB2/y) than in eyes with initial field loss (3.6 dB2/y; P = .016). This longitudinal study documents progressive disc damage prior to field loss in early glaucoma.

Follow-Up Studies↗
PubMed1993

Comparisons of methods to detect glaucomatous optic nerve damage.

PURPOSE: Various techniques of optic disc and nerve fiber layer evaluation may be used to detect structural glaucomatous damage. The authors compared several qualitative and quantitative methods to determine their relative sensitivities and specificities to detect the presence of glaucomatous visual field loss. METHODS: Fifty-one healthy eyes, 169 ocular hypertensive eyes with normal visual fields, and 132 glaucomatous eyes with early visual field defects were evaluated with qualitative and quantitative measures of structural damage to the optic nerve and nerve fiber layer. Qualitative evaluations were performed by three experienced masked observers who independently graded stereoscopic color disc and monochromatic nerve fiber layer photographs. Quantitative measurements of disc rim area and nerve fiber layer height were made with digitized image analysis of videographic images. Manual planimetric measurements of disc rim area were made from enlarged prints of stereoscopic optic disc photographs. Diagnostic precision was defined as the total proportion of correct diagnoses for the presence or absence of visual field loss. RESULTS: The diagnostic precision of results of a quantitative disc examination (81%) was greater than those of a qualitative nerve fiber layer examination (75%). Quantitative nerve fiber height measurement had the highest sensitivity rate (73%) and results of the qualitative disc examination had the highest specificity rate (87%) of the methods tested. CONCLUSION: The diagnostic precision of disc evaluation was superior to other methods, including nerve fiber layer examination, in correctly determining the presence of structural glaucomatous damage at the early visual field loss stage.

Adult↗
PubMed1993

Priority of test locations for automated perimetry in glaucoma.

PURPOSE: Static threshold automated perimetry is a demanding test which can be tiring for some patients. The authors investigate how to optimize early stages of the test which can shorten examination time and improve performance. The effectiveness of measuring every point twice to improve diagnostic precision (proportion of eyes correctly diagnosed as normal or glaucomatous) also was evaluated. METHODS: The authors evaluated the relative contributions of individual test locations to the sensitivity and specificity of static threshold perimetry. One hundred visual fields (Octopus Program G1) of 100 patients with open-angle glaucoma and early glaucomatous defects were used to rank the most frequently defective test locations. This sequence was modified so that highly correlated points were not ranked together. The sensitivities and specificities of the defined sequence of test presentations were then measured in a separate database of 70 normal controls and 70 patients with early glaucomatous visual field defects. RESULTS: Sensitivity and specificity were, respectively, 80% and 80% after 12 locations, 89% and 89% after 26 locations, and 97% and 99% after all 59 test locations. The information obtained with the first phase alone approximates that of both phases. CONCLUSION: Staging of locations tested with automated perimetry in glaucoma may be a valuable method to reduce examination time, minimize fatigue effects, and optimize diagnostic information. Retesting every point does not improve diagnostic precision.

Glaucoma, Open-Angle↗
PubMed1992

Long-term fluctuation of the visual field in glaucoma.

We examined 756 automated threshold visual fields of 167 eyes of patients with glaucoma to determine the magnitude of the long-term fluctuation at individual test locations. Eyes were grouped into clinically stable or nonstable groups according to predefined clinical criteria. At individual test locations with initial sensitivities of 25 to 30 dB in clinically stable eyes, the 5th to 95th percentile value for subsequent measurements was +/- 4 dB. For initial sensitivities of 20 dB, this 90% range was +/- 6 dB, and for sensitivities 15 dB or less, the 90% range of subsequent values spanned sensitivities from almost zero to normal values. Long-term fluctuation correlated with short-term fluctuation (r = .363, P less than .0005), but not with age or intraocular pressure. There was no correlation of long-term fluctuation with eccentricity after correcting for the decreased sensitivity associated with greater eccentricity. Long-term fluctuation was greater in the nonstable group than in the stable group (P less than .0005). These data provide limits for fluctuation in stable patients with glaucoma, which will help guide clinical decisions about visual field progression.

Adult↗
PubMed1992

Disc and field damage in patients with unilateral visual field loss from primary open-angle glaucoma.

To assess the temporal relationship between field and disc change in early glaucoma, 24 patients with unilateral visual field loss from primary open angle glaucoma were identified for planimetric optic disc measurements. Cross-sectional analysis of disc rim area was performed and compared to 25 age-matched normal controls. The mean (+/- SD) disc rim area in eyes with normal visual fields (1.10 +/- 0.31 mm2) was slightly larger than that of eyes with visual field loss (0.90 +/- 0.33 mm2). The mean disc rim area in the control group (1.49 +/- 0.19 mm2) was significantly different from both sets of eyes in the asymmetric primary open angle glaucoma patients (p = 0.000). These findings support the hypothesis that loss of the optic disc rim can be detected before perimetric abnormalities develop in patients with glaucoma.

Aged↗
PubMed1992

An optimal reference plane to detect glaucomatous nerve fiber layer abnormalities with computerized image analysis.

Nerve fiber layer height measured with respect to a standardized retinal reference plane is diminished by glaucoma. The definition of the reference plane influences the nerve fiber layer measurements. We empirically determined the best reference plane for measurement of nerve fiber layer height. Optimal parameters for measurement reproducibility were determined for a group of 6 normal and 6 glaucomatous eyes each imaged nine times. Optimal ability to distinguish normal from glaucomatous eyes was determined for a group of 33 normal eyes and 36 glaucomatous eyes each imaged once. Measurements with the smallest variability (root mean square error = 32 microns) and the highest sensitivity (83%) and specificity (88%) were achieved when the reference plane is defined by portions of the image from a peripheral temporal area 32 degrees wide, and for two peripheral nasal areas of 55 degrees width centered 30 degrees above and below horizontal. These parameters for the definition of the reference plane should provide measurements of nerve fiber layer height with the least variability and the greatest ability to discriminate between eyes with early glaucomatous damage and normal eyes.

Glaucoma↗
PubMed1992

Digital image analysis of optic nerve head pallor as a diagnostic test for early glaucoma.

We developed a computer-based technique to quantify optic nerve head pallor from videographically acquired digitized optic nerve images and tested the ability of pallor measurements to discriminate between normal eyes and eyes with early glaucoma. Corresponding pixel values from images obtained under 540 nm (green) and 640 nm (red) light with a videographic fundus camera were used to quantify optic nerve head pallor. A pallor density histogram was calculated for each eye, and contained values between 0 (red) to 1 (white). A measure of the distribution width of the histogram provided pallor measurements standardized to the measurements of the large veins of the disc. A database of one eye each of 44 normal controls and 70 patients with early open angle glaucoma was used to test the measurements for diagnostic sensitivity and specificity. These standardized pallor measurements did not perform better than absolute pallor measurements to discriminate between normal and glaucomatous eyes. The sensitivity and specificity of standardized pallor measurements (49% and 57%, respectively, for this database) were not as good as those for stereoscopic measurements of disc rim area in the same database (70% and 73%). Pallor measurements of this type do not appear to be sensitive or specific indicators of early glaucoma.

Aged↗
PubMed1992

Number of stimuli as a reliability parameter in perimetry.

Catch trials test patient performance during automated, static perimetry, but their adequacy to estimate reliability is uncertain even though up to 10% of the test time is reserved for catch trials. The 308 visual fields (program G1, all 3 phases, Octopus 201) of 308 eyes of 308 glaucoma, suspected glaucoma, and normal subjects were studied. The 108 visual fields (mean sensitivity > 10 dB; corrected loss variance < 50 dB2) without false responses to catch trials were considered reliable. A multiple linear regression analysis of these 108 fields was performed and revealed the following result (r2 = 0.751): Number of stimuli = 480 + (40.short-term fluctuation) + (8.8.the square root of the index corrected loss variance) - (2.2.mean sensitivity). This equation was used to estimate the number of stimuli required of a reliable subject to complete an examination. Excess stimuli would thus be a sign of reduced reliability. The difference between the estimated and the actual number of stimuli was called the 'stimulus discrepancy'. In 169 fields with false-positive and 58 fields with false-negative responses, the false-positive and false-negative responses correlated with the 'stimulus discrepancy' (r = 0.19, P = 0.014; r = 0.29, P < 0.026, respectively). The number of stimuli depends not only on reliability but also on the software and hardware of the perimeter. 'Stimulus discrepancy' may be an additional useful perimetric reliability parameter which does not require extra testing time.

Adult↗
PubMed1992

A surgical method to repair leaking filtering blebs.

Surgical revision of a chronically-thinned filtering bleb with a leak at the limbus is described. After surgical excision of the scarred cystic conjunctiva and Tenon's fascia surrounding the leaking bleb, relatively uninvolved conjunctiva and Tenon's fascia are mobilized with the help of a large relaxing incision in the superior fornix and sutured over the area of filtration. We have used this technique successfully in five cases to provide fresh tissue to repair the bleb leak and restore adequate filtration.

Conjunctival Diseases↗
PubMed1992

Discrimination between normal and glaucomatous eyes.

Discriminant analysis of quantifiable optic nerve, nerve fiber layer, and visual field measurements were used to assign eye to normal or glaucomatous groups. A database of 185 glaucoma patient with early visual field loss and 54 normal controls was used to develop and test the discriminant function. Parameters that discriminated best between normal and glaucoma were relative nerve fiber layer height and visual field mean defect. Cup-disc ratio, an estimate of optic nerve structure most commonly used by practitioners, was the weakest of the structural parameters to discriminate between normal and glaucoma. The combination of structural and functional measurements performed better than structural or functional measurements alone. When the discriminant function was applied to a group of 124 age-matched ocular hypertensives, 20% were assigned to the glaucoma group. Discriminant analysis of structural and functional measurements increases precision in identification of early glaucomatous damage, provides a probability that glaucomatous damage is present, and may help identify those ocular hypertensives who actually may have early damage.

Aged↗
PubMed1991

Regional and long-term variability of fundus measurements made with computer-image analysis.

We studied the variability of optic disk and peripapillary nerve fiber layer surface contour measurements made by use of computer-image analysis. Six hundred twenty-five measurements of surface contour were made on each eye by use of simultaneous stereoscopic videography. Regional differences in short-term measurement variability were studied in 12 eyes (six normal and six glaucomatous), each imaged nine times over several days. The widths of the 95% confidence interval for the measurements averaged 82 microns for the juxta-papillary surface and 132 microns for the disk surface. Measurements of peripapillary surface contour were significantly less variable than were measurements of the disk surface (P = .000). The greatest variability was detected along large blood vessels and at steep contours. Long-term variability was studied in a separate group of 30 clinically stable patients with glaucoma, each imaged three to six times over a period of more than one year. The widths of the 95% confidence intervals were 132 microns for the peripapillary surface and 217 microns for the disk surface. The long-term variability was significantly greater than the short-term variability (P = .000). The peripapillary nerve fiber layer surface, located away from the margins of large vessels, may provide the most dependable measurements of contour. These estimates of long-term variability of optic disk and peripapillary contour measurements provide clinically relevant confidence intervals with which to detect progressive glaucomatous nerve fiber damage.

Adult↗
PubMed1991

Rat retinal ganglion cells in culture.

A stable cell culture system of identified retinal ganglion cells would facilitate the investigation of cellular mechanisms of damage from glaucoma and other disorders. We have developed a reliable technique to culture retinal ganglion cells on a glial cells monolayer which extends viability and promotes extensive neurite outgrowth. Dissociated retinal cells from 5-7-day-old Sprague-Dawley rats were cultured on glial monolayers derived from rat cerebral hemispheres. Retinal ganglion cells were labeled with retrograde fluorescent markers injected into the superior colliculus or in culture with monoclonal antibody to Thy-1 antigen. Since Thy-1 antigen is not entirely specific for retinal ganglion cells, and fluorescent markers fade in older cultures, the identity of Thy-1 marked cells was confirmed with whole-cell electrophysiologic recordings. Labeled, physiologically intact retinal ganglion cells were identified for at least 31 days in culture. Many retinal ganglion cells showed neurite elongation of 2 mm or more and developed complex intercellular networks. This cell culture system may be used to form the basis for future studies of the electrophysiology and transport properties of retinal ganglion cells under normal culture conditions and under adverse conditions such as those that mimic ischemia or mechanical deformation.

Action Potentials↗
PubMed1990

The contour of the juxtapapillary nerve fiber layer in glaucoma.

Reliable structural markers for early glaucomatous optic nerve damage would facilitate the diagnosis of glaucoma at an early stage, possibly before visual field loss occurs. Computerized image analyses were used to develop and analyze new structural parameters for glaucomatous optic nerve damage. Multiple measurements of relative juxtapapillary nerve fiber layer height were made in glaucoma patients (n = 112), patients suspected of having glaucoma (n = 87), and in age-matched normal control subjects (n = 53). The average relative nerve fiber layer (NFL) height differed in glaucoma patients and normal subjects by 70 microns, but differences exceeded 100 microns at the superior and inferior poles of the disc. Mean values for "glaucoma suspects" were intermediate between those for the normal subjects and glaucoma groups. The ability of summary statistics of relative NFL height measurements to discriminate between normal and glaucomatous eyes was superior to that of the standard disc parameters cup-disc ratio, disc rim area, and cup volume. Measurements of relative NFL height correlated with indices of visual field loss; the strongest correlations occurred for measurements at the superior and inferior poles. Measurements of juxtapapillary NFL height may prove useful to detect glaucomatous optic nerve damage at an early stage and to accurately recognize progressive nerve damage over time.

Female↗