M. Marraffa

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.

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.

Epidemiology of angle-closure glaucoma: Prevalence, clinical types, and association with peripheral anterior chamber depth in the Egna-Neumarkt 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.

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

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.

Comparison of Dynamic Contour Tonometry and Goldmann Applanation Tonometry in Deep Lamellar and Penetrating Keratoplasties

PURPOSE To compare the measurements of intraocular pressure (IOP) with dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in eyes with corneal graft and to evaluate the influence of corneal thickness (CCT), corneal curvature (CC), and astigmatism on these methods. DESIGN Prospective, observational cross-sectional study. METHODS Eighteen eyes of 18 patients after penetrating keratoplasty (PKP) and 14 eyes of 14 patients after deep lamellar keratoplasty (DLKP) underwent IOP evaluation with DCT and GAT, and measurements of CCT, CC, and astigmatism. Bland-Altman plots were used to evaluate the agreement between tonometers. Multivariate regression analysis was used to evaluate the influence of ocular structural factors and running suture on IOP measurements obtained with both tonometers. RESULTS IOP values obtained by DCT and GAT were strongly correlated in all eyes (r = .91; P < .001). DCT values measured 2.5 +/- 1.7 mm Hg higher than GAT readings (P < .001). A reduction of the mean IOP difference between DCT and GAT with an increase in IOP values (P < .001) was found. Regression analysis showed no effect of CCT, CC, astigmatism, and running suture on both DCT and GAT readings, either in DLKP or in PKP eyes. CONCLUSIONS We found a good overall correlation between both tonometers but the agreement between instruments differs in high or low IOP ranges. The wide and varying 95% limits of agreement between DCT and GAT indicates that DCT provides IOP measurements on deep lamellar and penetrating keratoplasties which can be used in the clinical practice.

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.

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.

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%.

Simultaneous bilateral acute angle-closure glaucoma in a patient with subarachnoid hemorrhage.

PurposeTo present an unusual case of simultaneous bilateral acute angle-closure (AAC) glaucoma in a patient with subarachnoid hemorrhage due to an aneurysm involving the right middle cerebral artery. MethodsA 60-year-old woman with a clinically inexplicable bilateral nonreacting mydriasis after brain surgery underwent an ophthalmologic consultancy. The bilateral mydriasis was diagnosed as an unusual clinical presentation of simultaneous bilateral AAC glaucoma. One week after the AAC was bilaterally resolved, the patient underwent echographic examination because of the outbreak of a unilateral relapsed ocular hypertensive attack that required an ultrasound biomicroscopy (UBM) to be accurately diagnosed and treated. ResultsThe bilateral AAC regressed completely after pharmacologic therapy. UBM evaluation of the eye with recurrence of the angle-closure glaucoma attack was necessary to confirm the diagnosis of unilateral relapsed angle-closure glaucoma due to an unresolved pupillary block. A viscoelastic-aided opening of the angle and peripheral surgical iridectomy were performed. UBM and tonometry were performed intraoperatively to confirm the success of the surgical treatment. ConclusionsThe UBM allowed us to identify the pupillary block as the main mechanism involved in the pathogenesis of this unusual case of simultaneous bilateral AAC glaucoma. Despite the fact that drug-induced supraciliary uveal effusion and mydriasis due to surgical anesthesia have been frequently reported to contribute to this complication, we presumed that simultaneous intravenous administration of sedative drugs and adrenergic agonists, in a patient with individual biometric predisposing factors to the angle-closure, created the anatomic conditions which induced the pupillary block with obliteration of the trabeculum.