Sergio Perfetti

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.

Autonomic system activity and 24-hour blood pressure variations in subjects with normal- and high-tension glaucoma.

PurposeAs suggested by findings of abnormal responses to posture in patients with normal-tension glaucoma (NTG), cardiovascular autoregulation may also be defective in primary open-angle glaucoma (POAG). Patients and MethodsBoth 24-hour ambulatory blood pressure monitoring and the head-up tilt test were performed in 17 subjects with NTG and in 13 subjects with high-tension POAG (ht-POAG). These groups were compared with 17 age-matched healthy individuals. Subjects undergoing cardiovascular therapy were excluded. ResultsNo significant differences in diurnal and nocturnal blood pressure and heart rate were found between the groups. A significant reduction in diurnal heart rate variability was found in NTG (12.1 ± 2.8 bpm) compared with the ht-POAG (15.0 ± 2.4 bpm, P < 0.01) and control groups (15.8 ± 3.0 bpm, P = 0.01]). Nocturnal diastolic blood pressure variability was also reduced in NTG (6.9 ± 2.2 mm Hg) compared with controls (8.6 ± 2.3 mm Hg, P < 0.05]) as was heart rate variability (6.3 ± 1.4 vs 8.3 ± 2.6 in ht-POAG, P < 0.05), suggesting blunted blood pressure and heart rate modulation in NTG subjects. Spectral analysis of short-term heart rate variability showed a significant reduction of total power in the supine position (1064 ± 600 in NTG vs 1688 ± 889 ms2 in controls, P < 0.05]). This was not accompanied either by a physiological reduction in total power or in a high-frequency component during the passive orthostatic stimulus. These differences tend to become more prominent in the clinically more severe forms of NTG (as identified by scores based on the extent of optic disk excavation, visual field damage, and progression of disease). This would suggest a correlation between the extent of autonomic disorder and severity of glaucoma. The &agr; index (root-square of low-frequency heart rate to low-frequency blood pressure ratio) was lower in the supine position in NTG subjects (8.1 ± 3.1 vs 10.6 ± 3.3 ms/mm Hg in controls, P < 0.05), confirming the reduced baroreflex sensitivity. ConclusionsThe results confirm the hypothesis that dysfunction of autonomic control of the cardiovascular response may be a contributing pathogenetic factor in NTG, inducing a chronic ischemia of the optic nerve.

Comparison of the effects of nine beta-adrenergic blocking agents on intraocular pressure in rabbits

The intraocular pressure lowering effects of nine beta-adrenergic receptor blocking agents were compared using two different models of experimental ocular hypertension in rabbits. All the nine drugs possess, to different extents, a clear pressure-lowering action after topical administration into the conjunctival sac. For potency and duration of action, the best results were obtained with timolol and sotalol. Pindolol, oxprenolol, practolol, and propranolol are also fairly potent, while less impressive effects were produced by atenolol, butidrine, and metoprolol. With the exception of propranolol, all the drugs were well tolerated by the ocular tissues.

Experimental corticosteroid ocular hypertension in the rabbit.

Weekly subconjunctival injections of 4mg repository betamethasone, repeated over three weeks, produced a sustained increase of intraocular pressure (IOP) in 96 % of the treated rabbits. Treatment was generally well tolerated and important systemic toxic effects were present only in a few animals. The ocular hypertension so obtained was constant, well reproducible and sensitive to antiglaucoma drugs. The authors believe they have developed an animal model which is very suitable for testing the pressure-lowering effect of drugs and for other studies on ocular hypertension and glaucoma.

Effects of 2% ibopamine on pupil, refraction, anterior segment anatomy and intraocular pressure

The aim of the study was to determine the effects of a dopaminergic drug, 2% ibopamine, on the pupil, intraocular pressure and other ocular and ultrasound biometric variables. Thirty healthy subjects and 15 patients with primary open-angle glaucoma, aged from 40 to 78 years (mean age: 59.2 +/- 11), were included in two prospective open controlled trials. In the first, the mydriatic effect of 2% ibopamine and its inhibition and reversibility were evaluated in 15 healthy subjects using the alpha1-adrenergic drug, 0.5% dapiprazole. In the second, refraction, visual acuity, pupil diameter, intraocular pressure and 5 A-scan ultrasound biometric variables were evaluated in 15 healthy subjects and in 15 glaucoma patients. As early as forty min after administration of 2% ibopamine, a marked mydriatic effect (7.3 vs 3.9 mm; P < 0.0001), which was completely inhibited or reversed by 0.5% dapiprazole, was detected. The drug induced no changes in refraction, visual acuity or A-scan ultrasound biometric variables in any of the subjects examined. In healthy subjects, the intraocular pressure values were not changed to a statistically significant extent (13.8 vs 14.8 mm Hg; P = 0.668), whereas a slight, though significant, hypertensive effect (24 vs 22.2 mm Hg; P = 0.002) was observed in the glaucoma patients. The study confirms the intense mydriatic effect of 2% ibopamine with no changes in refraction, visual acuity or A-scan ultrasound biometric variables. The drug has no effect on intraocular pressure in healthy subjects, but induces a significant hypertensive effect in patients with initial glaucoma. This characteristic could be used for early diagnosis of primary open-angle glaucoma.

Intraocular-pressure-lowering effect of low-dosage combination of guanethidine and terbutaline in rabbit.

A low dosage combination of terbutaline plus guanethidine was applied topically to the eyes of rabbits with experimentally induced ocular hypertension, markedly lowering intraocular pressure. The effect of this combination is markedly greater than that produced separately by the two components at corresponding dosages and seems to be due to a true synergistic phenomenon. The low-dosage combination of terbutaline and guanethidine appears to be well tolerated, very potent and effective as a topical ocular hypotensive agent.