Comparison of Goldmann applanation tonometry and dynamic contour tonometry in healthy and glaucomatous eyes.

PURPOSE: To compare the measurements of intraocular pressure (IOP) with dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in healthy and glaucomatous eyes and to evaluate the influence of corneal thickness (CCT), corneal curvature (CC), axial length (AL), and age on these tonometric alternatives. METHODS: Three hundred eyes of 100 healthy subjects, 100 patients with primary open angle glaucoma, and 100 patients with primary angle-closure glaucoma underwent IOP evaluation with DCT and GAT, and measurements of CCT, CC, and AL. Bland-Altman plots were used to evaluate the agreement between tonometers. Regression analysis was used to evaluate the influence of ocular structural factors on IOP measurements obtained with both tonometers. RESULTS: Bland-Altman plots indicated that the 95% limits of agreement between tonometers were -1.4 to 6.6 mmHg. DCT values measured 2.6+/-1.9 mmHg higher than GAT readings (P<0.001). The mean IOP difference between DCT and GAT (DeltaIOP) was higher in healthy than in glaucomatous eyes and the magnitude of difference increased with increasing CCT. A significant reduction of DeltaIOP with an increase in both CCT (P<0.001) and IOP values (P<0.001) was found. Regression analysis showed no effect of CC, AL, and age on both DCT and GAT readings. In contrast to GAT (P<0.001), DCT measurements were not influenced by CCT (P=0.43). CONCLUSIONS: IOP readings obtained by DCT were higher and less affected by CCT than those by GAT. The DeltaIOP was higher in healthy than in glaucomatous eyes and decreased in relation to increased CCT and IOP values.

The effect of pneumatic trabeculoplasty on intraocular pressure: the results of a 6-month, open-label, multicenter study.

PURPOSE: To evaluate the effects of pneumatic trabeculoplasty (PNT) in ocular hypertension and glaucoma subjects. METHODS: A total of 63 consecutive subjects, either treated (79%) or untreated (21%), with intraocular pressure (IOP) between 20 and 25 mmHg were enrolled; the eye with higher IOP (or, in case of identical IOP, worse visual field) was treated with PNT, with the fellow eye used as control. Subjects underwent a baseline evaluation the day before treatment, two PNT treatments at day 0 and 7, visits at day 1, 8, 14, and at each month until the end of the study, which lasted 6 months. Safety was addressed at all visits; an IOP curve (at 8 and 10 AM, 2 and 4 PM) was obtained at baseline and during monthly visits. RESULTS: In PNT eyes, baseline IOP was 22.2-/+1.6 mmHg. Following PNT a statistically significant reduction of IOP occurred at all visits (p<0.0001), with a mean decrease ranging from -2.7-/+2.5 (-11.9-/+10.8%) to -3.6-/+2.6 mmHg (-16.0-/+11.6%); mean reduction was 12.8-/+11.5%. Although IOP diminished also in the control eyes after baseline (p<0.05), the change in IOP was significantly higher in PNT group at each visit (p<0.05). Mild side effects were experienced by 76% of subjects and they all resolved without sequelae. CONCLUSIONS: The results suggest the effect of this procedure in reducing IOP in glaucoma and ocular hypertensive subjects.

Ultrasound biomicroscopy and intraocular-pressure-lowering mechanisms of deep sclerectomy with reticulated hyaluronic acid implant.

PURPOSE: To evaluate the anatomic characteristics and intraocular pressure (IOP) lowering mechanisms of deep sclerectomy with reticulated hyaluronic acid implant (DS with RHAI) using ultrasound biomicroscopy (UBM). SETTING: Eye Clinic, Department of Neurological and Vision Sciences, University of Verona, Verona, Italy. METHODS: Thirty patients with primary open-angle glaucoma not controlled by medical therapy had DS with RHAI in 1 eye. A complete ocular examination and UBM study were performed 1, 3, 6, and 12 months postoperatively and thereafter at 6 month intervals. Eleven parameters were evaluated, the most important of which were IOP, surgical success in lowering IOP to 21 mm Hg or less with or without additional medical therapy, UBM appearance of the site of DS with RHAI, size of the decompression space, presence of a filtering bleb and supraciliary hypoechoic area, and scleral reflectivity around the decompression space. RESULTS: After a mean follow-up of 11.4 months +/- 4.7 (SD), the mean percentage reduction in IOP compared to preoperatively was 38% (from 26 +/- 4.5 mm Hg to 16.2 +/- 3.8 mm Hg; P =.0001). Twenty-four patients (80%) had an IOP less than 21 mm Hg; however, 7 of these eyes (23%) required additional IOP-lowering medical therapy. The operation failed in 6 patients (20%) despite additional therapy. Ultrasound biomicroscopy revealed a reduction in the size of the decompression space from 6 months postoperatively and its disappearance in 2 cases. The difference in size at the last follow-up and at 1 month postoperatively (maximum length 2.41 +/- 1.02 mm versus 3.53 +/- 0.51 mm) was significant (P =.0001). At the last examination, a filtering bleb was present in 18 patients (60%), a supraciliary hypoechoic area in 18 (60%), and hyporeflectivity of the scleral tissue around the decompression space in 14 (47%). These 3 UBM characteristics were detected singly and in various combinations. The simultaneous presence of all 3 characteristics in the same eye correlated significantly with a higher surgical success rate (P =.004). CONCLUSIONS: Ultrasound biomicroscopy showed that filtering bleb formation was frequent in eyes having DS with RHAI but that it was not the only surgically induced IOP-lowering mechanism. Increased uveoscleral and transscleral filtration may be equally important.

The relationship between intraocular pressure and glaucoma in a defined population. Data from the Egna-Neumarkt Glaucoma Study.

PURPOSE: To provide data on the prevalence of ocular hypertension and glaucoma and on the diagnostic validity of tonometry. METHODS: In this cross-sectional, population-based study, 4,927 subjects over 40 years of age were examined. Each subject underwent a complete ocular examination as part of the Egna-Neumarkt Glaucoma Study. These examinations were carried out by trained, quality-controlled ophthalmologists, according to a predetermined standard protocol that included a medical interview, applanation tonometry, computerized perimetry, optic nerve head examination and other ocular measurements. The following data were recorded: mean IOP, prevalence of ocular hypertension, primary open-angle glaucoma and normal tension glaucoma. Sensitivity, specificity and the predictive value of the tonometric test, as well as the distribution of IOP in the different groups were also determined. RESULTS: The overall prevalence of ocular hypertension, hypertensive primary open-angle glaucoma and normal tension glaucoma corresponded to 2.1, 1.4 and 0.6%, respectively. Other types of glaucoma accounted for a further 0.9%. The sensitivity and specificity of the tonometric test in recognizing glaucoma (cut-off between 21 and 22 mm Hg) were, respectively, 80.1 and 97.8%. The predictive values of the positivity and negativity of the test were 52.1 and 99.4%, respectively. CONCLUSIONS: The prevalence of ocular hypertension and glaucoma was similar to that found in several recent epidemiological studies. Tonometry alone is obviously not sufficient to ascertain or to exclude the presence of glaucoma; its diagnostic validity however is high and should never be underestimated. An elevated IOP is the main risk factor for glaucoma, with the degree of risk increasing as the level of IOP increases.

Vascular risk factors for primary open angle glaucoma: the Egna-Neumarkt Study.

OBJECTIVE: To assess the impact of vascular risk factors on the prevalence of primary open angle glaucoma. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Four thousand two hundred ninety-seven patients more than 40 years of age underwent a complete ocular examination in the context of the Egna-Neumarkt Glaucoma Study. INTERVENTION: Ocular examinations were performed by trained, quality-controlled ophthalmologists according to a predefined standardized protocol including medical interview, blood pressure reading, applanation tonometry, computerized perimetry, and optic nerve head examination. MAIN OUTCOME MEASURES: Prevalences of ocular hypertension, primary open-angle glaucoma, normal-tension glaucoma, and other types of glaucoma were determined. Correlation coefficients were calculated for the association between systemic blood pressure and age-adjusted intraocular pressure (IOP) and between age and both intraocular and systemic blood pressures. Odds ratios were computed to assess the risk of primary open-angle glaucoma and normal-tension glaucoma in relation to systemic hypertension or antihypertensive medication, blood pressure levels, diastolic perfusion pressure, and a number of other cardiovascular risk factors. RESULTS: A positive correlation was found between systemic blood pressure and IOP, and an association was found between diagnosis of primary open-angle glaucoma and systemic hypertension. Lower diastolic perfusion pressure is associated with a marked, progressive increase in the frequency of hypertensive glaucoma. No relationship was found between systemic diseases of vascular origin and glaucoma. CONCLUSIONS: Our data are in line with those reported in other recent epidemiologic studies and show that reduced diastolic perfusion pressure is an important risk factor for primary open-angle glaucoma.

Epidemiology of angle-closure glaucoma: prevalence, clinical types, and association with peripheral anterior chamber depth in the Egna-Neumarket Glaucoma Study.

OBJECTIVE: To assess the prevalence of primary angle-closure glaucoma (PACG), the frequency of its different clinical presentations, and its association with peripheral anterior chamber depth in a defined population in Northern Italy. DESIGN: Cross-sectional epidemiologic study in a defined population. PARTICIPANTS: All subjects resident in the Egna-Neumarkt area of the South Tyrol Region (Northern Italy) and more than 40 years of age were invited to undergo an ophthalmologic examination. INTERVENTION: After the screening examination, subjects with suspected glaucoma were re-examined at the screening center to confirm the diagnosis. All cases that still proved suspect after the second examination underwent a third phase of investigations and were classified as healthy or as definitely glaucomatous. Each subject was examined according to a standard protocol, including medical history interview, refraction and visual acuity determination, ocular biomicroscopy, evaluation of peripheral anterior chamber depth by means of the Van Herick method, applanation tonometry, optic disc evaluation, and computerized perimetry. Gonioscopy was not performed during initial screening but only in all selected patients in the second and third phases of investigations. The diagnosis of PACG was made on the basis of the concomitant presence of at least two of the following criteria: intraocular pressure > or = 22 mmHg, glaucomatous optic disc abnormalities, glaucomatous visual field defects. In addition, biomicroscopic or gonioscopic evidence of angle closure was also necessary. MAIN OUTCOME MEASURES: Percentage distribution of peripheral anterior chamber depths, prevalence of angle-closure glaucoma, and frequency of the different PACG clinical presentations. RESULTS: Four thousand two hundred ninety-seven subjects were examined (73.9% overall participation rate). The peripheral depth of the anterior chamber according to the Van Herick method was grade 2 in 14.7%, grade 1 in 2.5%, and grade 0 in 0.3% of the population. The overall prevalence of angle-closure glaucoma was 0.6% (26 cases). Five of these were cases of previous acute attacks resolved by therapy, three were cases of chronic angle-closure after acute attacks, three were intermittent angle-closure glaucomas, and 15 were chronic angle-closure cases. CONCLUSIONS: Occludable angles were more frequent than in other white populations previously studied. The prevalence of PACG is not as low as is usually believed; this type of glaucoma accounts for more than a quarter of all glaucomas found in the Egna-Neumarkt population. The most frequent clinical presentation is chronic angle-closure glaucoma.

Visual field defects and normal nerve fiber layer: may they coexist in primary open-angle glaucoma?

The retinal nerve fiber layer (RNFL) is the anatomical structure most sensitive to glaucoma injury. Before a functional loss such as a visual field defect is displayed, a large number of nerve fibers can be damaged. However, there are glaucoma patients in which an apparently normal RNFL coexists with evident visual field defects. A total of 54 eyes affected with primary open-angle glaucoma were studied. Visual field was examined with the Humphrey Field Analyzer (Zeiss) using program 30-2. The Nerve Fiber Analyzer II (Laser Diagnostic Technologies) was used to study the RNFL of these patients. Mean deviation of the visual field ranged from 6 to 31 dB in all eyes that were examined. The average thickness of the RNFL ranged from 20 to 90 microm. According to our previous experience 75 microm was fixed as the cutoff between normal and pathological values of RNFL thickness. We identified 5 eyes with a RNFL thickness over 75 microm and a visual field with a mean deviation over 6 dB; 9% of the studied eyes were found to have a visual field defect with no changes in RNFL. We conclude that not all subjects have the same number of fibers at birth and that it is therefore possible to underestimate the RNFL changes. Our study illustrates that the concept of normal and altered has to be considered as a relative one for all the aspects characterizing the glaucomatous disease.

Perimetric defects after a single acute angle-closure glaucoma attack.

BACKGROUND: This study was carried out to determine the effect of an acute attack of angle-closure glaucoma on the visual field. METHODS: A total of 53 eyes were examined 36-48 h after remission of an acute glaucoma attack by means of computerised perimetry (Humphrey 630 perimeter, 30-2 program). Perimetry was repeated after at least 1 month in 22 eyes. RESULTS: Perimetric defects, varying greatly in severity and primarily of the generalised type or concerning at least wide sectors of the field, were detected in 45 (85%) of 53 cases. The visual field was normal in the remaining 8 patients (15%). The upper nasal quadrants were the most frequently affected and the degree of eccentricity was most frequently involved within the 9 degrees -21 degrees area. In 7 of the 22 cases in which perimetry was repeated after 1 month, complete normalisation was noted in the visual field. CONCLUSIONS: An isolated attack of acute glaucoma produces in most cases a perimetric defect of generalised or mixed type. This may be reversible. The most affected zones were the upper half of the visual field and the 9 degrees -21 degrees area.

Prevalence of glaucoma and intraocular pressure distribution in a defined population. The Egna-Neumarkt Study.

OBJECTIVE: The purpose of the study is to assess the prevalence of various types of glaucoma and to determine the intraocular pressure (IOP) distribution in a defined population in an Italian rural community. DESIGN: A cross-sectional epidemiologic study in a defined population was planned. After the screening examination, the subjects with suspected glaucoma were re-examined at the screening center in order to confirm the diagnosis. All cases that still proved suspect after the second examination underwent a third phase of investigations at the Ophthalmologic Division of Bolzano Hospital, and were classified as healthy or definitely glaucomatous. PARTICIPANTS: All subjects residing in the Egna-Neumarkt area of Alto Adige region (Northern Italy) and over 40 years of age were invited to undergo an ophthalmologic examination. INTERVENTION: Each subject was examined according to a standard protocol, including computerized perimetry, applanation tonometry, evaluation of anterior chamber depth and optic disc, and a medical history interview. The diagnosis of glaucoma was based on the presence of at least two of the following criteria: IOP > or = 22 mmHg, glaucomatous optic disc abnormalities, and glaucomatous visual field defects. Ocular hypertension was defined as IOP > or = 22 mmHg without visual field or glaucomatous optic disc abnormalities. MAIN OUTCOME MEASURES: Participation rate, mean IOP, prevalence of glaucoma (primary open-angle glaucoma, primary angle-closure glaucoma, normal-tension glaucoma, secondary glaucoma), and ocular hypertension were determined. RESULTS: Of a total of 5816, 4297 subjects were examined (73.9% overall participation rate). Intraocular pressure showed a Gaussian-like distribution curve skewed to the right. Mean IOP increased with age, and was slightly higher in men (15.14 mmHg) than in women (14.94 mmHg). The overall prevalences of ocular hypertension, primary open-angle glaucoma, primary angle-closure glaucoma, and normal-tension glaucoma were 2.1%, 1.4%, 0.6%, and 0.6%, respectively. Only 28 of 210 patients with glaucoma or ocular hypertension had been diagnosed prior to the screening. CONCLUSIONS: The distribution of IOP and the prevalence of the different types of glaucoma were similar to those found in other white populations.

The nerve fibre layer in ocular hypertension. Preliminary results.

A group of healthy subjects (IOP < 22 mmHg) and a simple ocular hypertension group (IOP > or = 22 mmHg) were examined with a view to checking if there were any differences between their nerve fibre layers. Results indicate thinner fibres in the ocular hypertensives significantly correlative with pressure increase. Among the two groups, some corresponding fibre thicknesses were found.

Does nerve fiber layer thickness correlate with visual field defects in glaucoma? A study with the nerve fiber analyzer.

The Nerve Fiber Analyzer, a confocal scanning laser ophthalmoscope, was used to measure the thickness of the retinal nerve fiber layer (NFL) in a glaucoma population. The authors studied the correlation between NFL thickness and the perimetric defects. The NFL was found to be statistically thinner in comparison to a normal control group of subjects. The correlation between the perimetric index MD and the NFA was statistically significant only for the lower quadrant of retinal NFL. The correspondence between thinner NFL and perimetric defects was investigated.

Ultrasound biomicroscopy and corneal endothelium in Nd:YAG-laser iridotomy.

BACKGROUND AND OBJECTIVE: Thirty eyes affected by angle-closure glaucoma that had undergone YAG-laser iridotomy were studied to evaluate variations of central anterior chamber depth, width of the angle, and loss of endothelial cells after laser treatment. PATIENTS AND METHODS: These parameters were determined before and after iridotomy: endothelial cell count using a "non-contact" specular biomicroscope, and anterior chamber depth and angle width using ultrasound biomicroscopy (UBM). The width of the iridotomy and the distance of the iridotomy from the scleral spur and from the corneal endothelium were also measured by UBM, after laser treatment. RESULTS: Results confirmed that, after iridotomy, there is not a significant variation in the central depth of the anterior chamber: it goes from 2.02 mm pre-laser to 2.07 +/- 0.38 mm post-laser. There is, however, a statistically significant increase in the angle (P < .001), which goes from 10.69 +/- 8.88 degrees (0.109 +/- 0.07 mm) to 21.03 +/- 11.28 degrees (0.183 +/- 0.09 mm). The mean dimension of the iridotomies was 0.46 +/- 0.13 mm. The mean endothelial cell count was 55.8 +/- 4.08 cells per linear millimeter before laser treatment and 47.01 +/- 5.39 cells per linear millimeter afterward (P <.001). CONCLUSION: This study confirms that YAG-laser iridotomy leads to a reduction in the average endothelial cell density. The loss of these cells is inversely proportional to the distance of the iridotomy from the endothelium and the scleral spur.

HPR perimetry and Humphrey perimetry in glaucomatous children.

Fifteen children aged less than 11 years, affected by congenital glaucoma, underwent visual field testing using two different methods: conventional computerized perimetry (24-2 Humphrey program) and High Pass Resolution perimetry (Ring test). The aim of the study was to discover which of the two perimetric techniques was more suitable for younger patient. Results showed that HPR perimetry is more suitable to children. Reasons include the short duration of the test (5 min), and the appearance like a pleasant game to 80% of the subjects tested. In addition it proved to be better than Humphrey test because of the minimal possibilities of memorisation with a reproducibility factor of 68% in our sample and because of the reliable results and satisfactory evaluation in 76% of the eyes examined.

Subconjunctival THC:YAG laser sclerostomy for the treatment of glaucoma: preliminary data.

A subconjunctival thermal sclerostomy was performed using the recently developed THC:YAG laser in 33 eyes with a variety of glaucomas in which, in most cases, neither medical therapy nor previous procedures had been successful in controlling intraocular pressure (IOP). The mean preoperative IOP was 27.5 +/- 7.5 mm Hg with maximum medication. The laser procedure was quick and easy, with minimal manipulation of tissues; complications were clinically insignificant. The day after the operation, 23 eyes had an IOP less than 18 mm Hg; in the other 10, it was unchanged. In most of the eyes, an obvious filtering bleb developed at the site of the sclerostomy. The internal opening of the sclerostomy was visible on gonioscopy, except in five cases, in which it was plugged by a fold of the iris root. One year after the operation, IOP was controlled in three eyes without medication and in 18 with medication. IOP remained uncontrolled in the remaining 12 eyes.

Effects of the association of alpha and beta-blocking agents in glaucoma.

Twenty patients with POAG and early visual field changes, already under treatment with 0.5% timolol were randomly assigned to additional topical treatment with 0.5% dapiprazole or placebo. After six months of treatment no differences were observed between the groups for what concerns visual field. After six months of treatment visual field, visual flicker discrimination and contrast sensitivity proved to be constant without differences between the groups. On the contrary, mean IOP was found to be significantly lower in the dapiprazole group.

Comparison of different screening methods for the detection of visual field defects in early glaucoma.

The effectiveness of three different automated perimetry strategies for the screening of glaucomatous visual field defects was studied on 182 eyes of glaucoma suspects. The results were compared with those obtained with the Octopus G1 program. On this particular sample of population the results are as follows. Henson perimeter: sensitivity 59.4%, specificity 88%. Humphrey perimeter (Armaly full field test): sensitivity 64.2%, specificity 64.2%. Perikon perimeter (Genoa glaucoma screening): sensitivity 55%, specificity 90.4%. Octopus perimeter (G1 program): sensitivity 92.1%, specificity 83%.

[Study of color perception using a new color test and desaturated panel D 15 in normal subjects and diabetics]. / Etude de la perception des couleurs au moyen du new color test et du panel D 15 désaturé chez des sujets normaux et diabétiques.

The authors used two tests (the Lanthony's New Color Test and the desaturated Panel D 15 test) to evaluate color vision in 235 subjects (235 eyes) of which 80 normal and 155 diabetic (85 with background retinopathy and 70 without retinopathy, as demonstrated by fluorescein angiography). The diabetic patients with maculopathy or macular oedema, with mixed or proliferative retinopathy, or with any form of advanced degenerative retinopathy were excluded from this study. The New Color Test was performed in accordance with Lanthony's standardized method, applying only the separation phase (to quantifying the color perception defect, if any) in photopic illuminance conditions at 250 lux. The desaturated Panel D 15 (qualitative classification test) has been performed at illuminance of 500 lux. Both normal and diabetic subjects were divided into two age groups (below and above 45 years) and the discriminatory value of two tests has been assessed in relation to age, diabetes and background retinopathy. The New Color Test showed a highly significant difference between normal subjects and diabetics of comparable age with background retinopathy. There was also a highly significant difference between diabetics with and without retinopathy. On the other hand, the difference between normal subjects and diabetics without retinopathy proved significant in the below-45 age group and no-significant in the above-45 age group. The results obtained in the desaturated Panel D 15 test have been similar: below the 45 years of age all differences among the three subject groups proved significant, whereas in the above-45 age group no significant differences were observed.(ABSTRACT TRUNCATED AT 250 WORDS)