Glaucoma In Population Research Articles

Awareness of glaucoma in the rural population of Southern India

To explore the awareness of glaucoma amongst the rural population of Andhra Pradesh, India. A total of 7775 subjects of all ages, representative of the rural population of Andhra Pradesh, participated in the Andhra Pradesh Eye Disease Study. The responses of subjects older than 15 years (n=5573) who completed a structured questionnaire regarding awareness (heard of glaucoma) and knowledge (understanding of disease) of glaucoma formed the basis of this study. Awareness of glaucoma (n=18; 0.32%) was very poor in this rural population, and females were significantly less aware (p=0.007). Awareness of glaucoma was also significantly less among illiterate persons (p<0.0001), and socially backward population (p<0.0001). Majority of the respondents who were aware of glaucoma (n=10; 55.6%) did not know if visual loss due to glaucoma was permanent or reversible. The major source of awareness of glaucoma in this population was TV/magazines and other media followed by information from a relative or acquaintance suffering from the disease. Awareness of glaucoma is very poor in the rural areas of southern India. The data suggest the need for community-based health education programmes to increase the level of awareness and knowledge about glaucoma.

Screening for Glaucoma in a General Population with the Non-Mydriatic Fundus Camera and the Frequency Doubling Perimeter

To evaluate the usefulness of non-mydriatic fundus camera (NMFu-camera) and frequency doubling perimeter (FDP) for detecting glaucoma in a general population. This prospective observational multicenter study consisted in screening for glaucoma in the populations of three Belgian cities. Intraocular pressure (IOP) was measured with non-contact pneumo-tonometer (NCT) and applanation tonometry (AT) if NCT IOP was > or = 17 mmHg. Visual field was screened with FDP (C-20-5) and digitized optic disc photographs (ODPs) were taken with NMFu-camera. FDP was considered abnormal if at least one defective point was found. ODPs were graded as normal or glaucomatous by consensus of three glaucoma specialists. Optic disc and visual field results were matched per eye. Subjects with known ocular hypertension and/or treated primary open angle glaucoma were excluded from the analysis. A total of 1620 subjects were included in the study. Their mean age was 63.2 years. AT IOP was > 21 mmHg in 8.2%. A total of 98.1% of ODPs could be interpreted. Glaucomatous optic discs were detected in 3.5% of the subjects. In this group only 24% had an AT IOP > or = 22 mmHg. FDP was abnormal in 44.5%. The sensitivity and specificity of FDP to identify patients with an optic disc graded as glaucomatous were 58.6% and 64.3% respectively. The combined use of the NMFu-camera and the FDP is a feasible method for an initial glaucoma mass screening. NMFu-camera may be a useful and quick method to screen for glaucomatous damage in a community. FDP in screening strategy was revealed to be not sensitive enough when setting the cut-off value at one defective test location. IOP measurements were confirmed to be a poor tool to detect glaucomatous damage.

The use of RADAAR (ratio of rim area to disc area asymmetry) in detecting glaucoma and its severity

Contexte: Une étude antérieure a démontré que le rapport d'asymétrie entre la surface des anneaux rétiniens et celle des papilles optiques de l'œil adelphe (RAARPO) est associé au diagnostic de glaucome chez les patients qui présentent une grande différence de sévérité de la maladie entre les deux yeux. De plus, ce rapport d'asymétrie permet de distinguer ces patients des patients sans glaucome ou de ceux suspects de glaucome. Cette étude a pour but d'évaluer la corrélation entre le RAARPO et le diagnostic et la gravité du glaucome dans une grande population glaucomateuse.Méthodes: Nous avons révisé les dossiers de 140 patients porteurs d'un glaucome à angle ouvert, normotensif ou pseudoexfoliatif, choisis au hasard et évalués au service du glaucome d'un centre de soins tertiaires de Philadelphie entre les mois de janvier 1996 et avril 2000. La surface des papilles, celle des anneaux rétiniens, le rapport anneau/papille, l'écart type et l'écart moyen ont été estimés avec le tomographe de la rétine Heidelberg (HRT) et la pression intraoculaire (PIO) maximale a été mesurée. L'analyse des papilles et des champs visuels ont établi la gravité du glaucome du premier œil et l'œil adelphe a été classé « meilleur » ou « pire » que celui-ci.Résultats: Nous avons mesuré une corrélation significative entre le RAARPO et la PIO (r = 0,23, p < 0,03), l'écart moyen (r= −0,22, p < 0,02), le rapport entre l'anneau rétinien et la papille optique (r= 0, 19, p < 0,03) et l'état de la papille indiquant une atteinte glaucomateuse du nerf optique (r = 0,17, p < 0,05) du « pire » œil. Nous avons également établi une corrélation entre les différencs groupes de RAARPO et la différence entre les deux yeux quant à l'écart moyen (p < 0,05) et le rapport anneau rétinien/papille optique (p < 0,02).Interprétation: Le RAARPO, nouvelle mesure de l'asymétrie des deux yeux obtenue avec le HRT, est associé au diagnostic du glaucome et à son degré de gravité.

Quality of life in glaucoma patients: Regression analysis and correlation with possible modifiers

PURPOSE To verify the quality of life in a Brazilian glaucoma population and the influence of possible modifiers (e.g., visual acuity, visual field impairment). METHODS Forty-five consecutive patients from CEROF - Federal University of Goiás, Brazil were included prospectively in the study. The quality of life was assessed using the Portuguese version of the VFQ. Possible modifiers were evaluated, initially separately with the Spearman's Correlation and then together in a regression model. RESULTS The mean age was 59.6 ± 12.4 years. The mean quality of life score was 79 ± 15 (range 45-100). Age (r = −0.402, p = 0.006), visual acuity in the better eye (r = −0.497, p = 0.001) and in the worse eye (r = −0.608, p < 0.001), Hodapp-Parrish-Anderson visual field grading scale in the better (r = −0.353, p = 0.01) and worse eye (r = −0.387, p = 0.009), visual field Mean Deviation (MD) in the better (r = 0.355, p = 0.01) and worse eye (r = 0.320, p = 0.04) and ability to perform a visual field test in both eyes (r = −0.397, p = 0.007) were significantly correlated with the quality of life scores. However, only age (younger, better quality of life, p = 0.008) and visual acuity in the better eye (direct relation, p = 0.04) were significant in the regression model (r = 0.633, r2 = 0.401). CONCLUSIONS The VFQ may be a useful tool to assess the quality of life in glaucoma patients. The preliminary results indicate that age and visual acuity in the better eye are the main factors related to the quality of life in these patients.

Glaucoma in a rural population of southern India: The Aravind comprehensive eye survey

Purpose To determine the prevalence of glaucoma and risk factors for primary open-angle glaucoma in a rural population of southern India. Design A population-based cross-sectional study. Participants A total of 5150 subjects aged 40 years and older from 50 clusters representative of three southern districts of Tamil Nadu in southern India. Methods All participants had a comprehensive eye examination at the base hospital, including visual acuity using logarithm of the minimum angle of resolution illiterate E charts and refraction, slit-lamp biomicroscopy, gonioscopy, applanation tonometry, dilated fundus examinations, and automated central 24-2 full-threshold perimetry. Main outcome measures Definite primary open-angle glaucoma (POAG) was defined as angles open on gonioscopy and glaucomatous optic disc changes with matching visual field defects, whereas ocular hypertension was defined as intraocular pressure (IOP) greater than 21 mmHg without glaucomatous optic disc damage and visual field defects in the presence of an open angle. Manifest primary angle-closure glaucoma (PACG) was defined as glaucomatous optic disc damage or glaucomatous visual field defects with the anterior chamber angle partly or totally closed, appositional angle closure or synechiae in the angle, and absence of signs of secondary angle closure. Secondary glaucoma was defined as glaucomatous optic nerve damage and/or visual field abnormalities suggestive of glaucoma with ocular disorders that contribute to a secondary elevation in IOP. Results The prevalence (95% confidence interval) of any glaucoma was 2.6% (2.2, 3.0), of POAG it was 1.7% (1.3, 2.1), and if PACG it was 0.5% (0.3, 0.7), and secondary glaucoma excluding pseudoexfoliation was 0.3% (0.2,0.5). On multivariate analysis, increasing age, male gender, myopia greater than 1 diopter, and pseudoexfoliation were significantly associated with POAG. After best correction, 18 persons (20.9%) with POAG were blind in either eye because of glaucoma, including 6 who were bilaterally blind and an additional 12 persons with unilateral blindness because of glaucomatous optic neuropathy in that eye. Of those identified with POAG, 93.0% had not been previously diagnosed with POAG. Conclusions The prevalence of glaucoma in this population is not lower than that reported for white populations elsewhere. A large proportion of those with POAG had not been previously diagnosed. One fifth of those with POAG had blindness in one or both eyes from glaucoma. Early detection of glaucoma in this population will reduce the burden of blindness in India.

Effect of Tonometry on a Glaucoma Population Study

The purpose of this study was to evaluate the influence of tonometry in detecting the occurrence of glaucoma. The subjects, 845 out of 3,488 residents aged 40 years or older, were examined according to standard protocols, including tonometry, slit lamp examination, fundus photography, and automatic perimetry as a recall examination. The intraocular pressure in each subject was measured by both Goldmann applanation tonometer(GAT) and noncontact tonometer CT-70 (NCT). The mean +/- standard deviation intraocular pressure measured by GAT was 15.52 +/- 2.57 mmHg, and 15.03 +/- 2.90 mmHg by NCT. There was a statistically significant correlation(p < 0.0001). The difference between pairs of measurements by GAT and NCT was 0.50 +/- 1.93 mmHg. There was no influence of tonometry in detecting the incidence of glaucoma, which was 4.14%; primary open-angle glaucoma 0.59%, normal tension glaucoma 2.6%, primary angle-closure glaucoma 0.47%, and other types of glaucoma 0.48%. The detection of ocular hypertension was different, and was 2.13% with GAT and 2.72% with NCT. In our study, the influence of tonometry in detecting the incidence of glaucoma was very small. A noncontact tonometer is considered to be useful for glaucoma population study.

Red and/or blonde hair association with pigmentary glaucoma in Israel

To assess the prevalence of red and/or blonde hair in a defined pigmentary glaucoma (PG) population and to compare their clinical findings with those of PG patients with black or brown hair. Hair color was studied in 35 consecutive PG patients and 35 consecutive primary open angle glaucoma (POAG) patients who served as controls. Patients were classified into red and/or blonde hair group or into black or brown hair group. Clinical characteristics were contrasted between PG patients of red and/or blonde hair with PG patients of black or brown hair. Of the 35 PG patients, 19 (54.3%) had red and/or blonde hair and 16 (45.7%) had black or brown hair. Of the 35 POAG patients, two (5.8%) had red and/or blonde hair and 33 (94.2%) had black or brown hair. This difference in prevalence of hair color is highly significant (P < 0.001; chi2). Clinical characteristics of the PG patients (age at initial diagnosis, gender, positive family history for glaucoma, initial IOP, refraction, severity of optic nerve damage and prevalence of retinal detachment) were similar in the red and/or blonde hair and the black or brown hair groups. A very high prevalence of red and/or blonde hair was found among PG patients in Israel. Should supportive evidence for this association accumulate subsequent to this report, screening of people with these hair colors for PG may be justified.

Contribution of multiple glaucoma medications to visual function and quality of life in patients with glaucoma

Background: Previous studies examining the correlation between medical treatment and overall quality of life in patients with glaucoma assessed differences between a glaucoma population and a matched group (without glaucoma) and were not aimed specifically at detecting a relation between visual acuity, visual field status and medication use, and visual function and quality of life. We performed a study to determine this relation in patients with chronic open-angle glaucoma (COAG).Methods: The study was cross-sectional. Of 235 English-speaking patients with a diagnosis of COAG, normal-pressure glaucoma or suspected glaucoma (receiving therapy) seen in a university-based glaucoma practice between Feb. 1 and Apr. 30, 1998, 224 (95.3%) agreed to participate. All subjects completed two questionnaires: the Visual Function Assessment and the EQ-5D, assessing health status (quality of life). Visual acuity, diagnosis, age, sex, country of birth, type and number of medications for topical and for oral use, dosage, and history of laser treatment and surgery were extracted from the medical record. Pearson rank correlation and multivariate analyses were performed.Results: On univariate analysis visual function was correlated with age, visual acuity, number of glaucoma medications, number of applications of eyedrops, mean deviation in better eye, mean deviation in worse eye, and lower hemifield involvement in both eyes. On multivariate analysis only visual acuity and visual field status were independently associated with visual function. Univariate analysis showed that health status was correlated with age, visual function and number of medications for oral use; however, age failed to retain statistical significance in the regression analysis. Interpretation: Our results suggest that the number of glaucoma medications is not predictive of quality of life.

The risk of obstructive airways disease in a glaucoma population.

Asthma and chronic obstructive pulmonary disease (COPD), defined as obstructive airways disease (OAD), are two common chronic conditions especially in the elderly. Glaucoma is also a common disease in the elderly with a prevalence close to 5% among those older than 75 years. Most medical therapy for glaucoma is given as eye drops. It has been described that small amounts of systemically absorbed beta-blockers can produce significant respiratory adverse events in predisposed patients. Population-based cohort study with nested case-control analysis using the UK General Practice Research Database (GPRD). We studied the prevalence of OAD in a cohort of patients 60 to 85 years old with a first ever diagnosis of glaucoma and compared it to the prevalence in an age- and sex-matched cohort sampled from the general population. We also calculated the RR and 95% CI of worsening asthma in non-severe asthma patients among the two cohorts. Incidence of OAD was studied in a cohort of glaucoma patients 60 to 85 years old and in an age- and sex-matched cohort from the general population. The prevalence of OAD was the same between the glaucoma cohort and the general population (OR 1.1; 95% CI 0.9-1.4). The risk of worsening asthma associated with glaucoma was OR 1.2 (95% CI 0.5-2.8). The incidence of OAD was similar in both cohorts. Current users of ophthalmic drugs presented a RR of 1.2 (95% CI 0.8-1.9) of developing asthma compared to non-users in the glaucoma population. The risk in the first month of treatment with topical beta-blockers was 2.1 (95% CI 0.7-6.7). We did not find an association between glaucoma and OAD. Use of topical glaucoma medication was not associated with a major increased risk of asthma.

Effects of glaucoma medications on the cardiorespiratory and intraocular pressure status of newly diagnosed glaucoma patients

AIMSTo evaluate the short term cardiovascular, respiratory, and intraocular pressure (IOP) effects of four glaucoma medications in newly diagnosed glaucoma patients.METHODS141 newly diagnosed glaucoma patients were recruited and underwent a...

Topical carbonic anhydrase inhibition increases ocular pulse amplitude in high tension primary open angle glaucoma

BACKGROUNDOcular pulse amplitude (OPA) is reduced in normal tension primary open angle glaucoma (NTP) patients when compared with healthy age matched controls (CTL) while increased OPA appears to protect ocular...

Glaucoma in Munster

The question was: are all persons with glaukoma in the town of Munster in treatment? The author recorded all patients with glaucoma and were subdivided into the different glaucoma diseases. The author analysed 10 glaucoma screenings of white populations published in the past 30 years and compared these with the glaucoma population in Munster. The results of these comparisons are ambiguous. In one survey (Tierp) 50% more POAG patients were found than are known in Munster; another (Baltimore) had the same distribution as Munster. With our knowledge about the course of untreated glaucoma, such uncertainty is, in tolerable, and the author suggests that glaucoma screening be offered to part of the population, like cancer screening.

Analysis of Reliability Indices from Humphrey Visual Field Tests in an Urban Glaucoma Population

Visual field assessment is extremely important in glaucoma management, but interpretation is affected by the quality of the patient's performance. The authors have investigated the reliability of visual field performance by a randomly selected sample of the chronic glaucoma population at an urban tertiary care practice. Patient reliability in Humphrey automated visual field testing was studied in 106 randomly selected chronic open-angle glaucoma patient charts, which provided 768 tests (mean, 7.2 +/- 4.8 fields; range, 2-18 fields). Reliability criteria were established as less than 20% fixation losses, less than 33% false-negative error, and less than 33% false-positive error, as recommended by Humphrey Instruments, Inc (San Leandro, CA). Patients performed reliably in 61% of right eye fields, 58% of left eye fields, and 59.5% overall. Of the 106 patients, only 35 (33%) were always reliable in both eyes, whereas 8 (7.5%) were always unreliable in both eyes. The most common cause of unreliability was fixation loss (39%), whereas false-positive error (5%) and false-negative error (9%) were less frequent. A more severely depressed mean deviation correlated significantly with poorer performance on the three reliability indices, with false-negative error having the greatest correlation, followed by fixation loss and false-positive error. Corrected pattern standard deviation correlated closely only with false-negative error. Prolonged test time also correlated with all three reliability indices. Age was a significant factor for fixation loss but not for false-negative or false-positive error. The authors conclude that fewer than two thirds of the Humphrey visual fields were reliable with the authors' urban tertiary care population of patients with glaucoma. Relaxing the fixation loss criterion to less than 33% improved the rate of reliability to approximately 75%. The severity of glaucomatous visual field defects, test time, and age were identified as factors influencing the reliability of the Humphrey visual fields.

Influence of the "fatigue effect" on the mean deviation measurement in perimetry.

To quantify the influence of the reduction of the threshold during perimetric study on the mean deviation (MD). One hundred-57 eyes of 94 patients with ocular hypertension and glaucoma and 123 eyes of 62 normal patients were explored using the Humphrey perimeter with a Delphi program specially modified to make 12 consecutive measurements of the MD. Hypertension and glaucoma population: during the test, which lasted 13.88 +/- 1.25 minutes, the estimated MD showed a tendency to decrease by 2.9 dB on average from the beginning to the end of the exploration. This diminution was more important in patients with deeper defects, in whom the average was near 6 dB (Normal population: 13.26 +/- 2.91 minutes; mean decrease 2.22 dB). It was found that, in fact, this reduction is related to age (p < 0.01) and not to the level of the glaucomatous defect. Age, through a "fatigue effect", influences the measured depth of the glaucomatous defect. Since in a conventional exploration the thresholds of the points are obtained from the whole test, we can estimate that the "fatigue effect" influences the MD to the extent of approximately half (1.45-1.11 dB), with respect to the numbers indicated above.

Evaluation of FASTPAC, a New Strategy for Threshold Estimation with the Humphrey Field Analyzer, in a Glaucomatous Population

A new fast strategy for the estimation of threshold, FASTPAC, has been introduced for the Humphrey Field Analyzer. The aim of this study is to evaluate the performance, in a glaucomatous population, of FASTPAC compared with the standard full-threshold 4-2-decibel (dB) double-staircase strategy. The sample consisted of 30 glaucoma patients experienced in automated perimetry, ranging in age from 26 to 84 years. One eye of each patient was examined with both strategies using program 24-2, target size III. The order of strategy was randomized for each patient. The results were analyzed using analysis of covariance for a two-period crossover trial. Mean deviation, pattern standard deviation, short-term fluctuation, corrected pattern standard deviation, number of stimulus presentations, and examination time were analyzed separately; test sequence and severity of field loss were considered as between subject factors and age as a covariate. The FASTPAC algorithm demonstrated a 36% saving in examination time (P < 0.001), a lower mean deviation (0.91 dB) (P < 0.001), and a greater short-term fluctuation (0.64 dB) (P = 0.008). The differences in mean deviation (P = 0.015) and short-term fluctuation (P = 0.033) became greater with an increase in age. As the severity of the field loss increased, the short-term fluctuation increased (P = 0.043), and examination time was increased for the FASTPAC strategy, while it became shorter for the standard full-threshold strategy (P = 0.033). The FASTPAC strategy reduced the examination time but exhibited a decreased estimate of field severity and a greater intra-test variance.

Vision Loss in the Glaucoma Population

Vision Loss in the Glaucoma Population

Pseudo‐exfoliation, IOP and glaucoma

On the basis of a glaucoma survey in a total population greater than or equal to 65 years of age, the IOP in eyes with and without pseudo-exfoliation (PE) has been compared. The average IOP was 22.2 mmHg in eyes with PE versus 17.4 in eyes without. The corresponding averages in eyes without glaucomatous damage were 18.6 and 17.1 mmHg, and in eyes with glaucoma 31.5 and 25.5 mmHg. The IOP elevation connected with the PE process was 4.8, 1.5, and 6.0 mmHg in the total, normal and glaucomatous population, respectively. The IOP frequency distribution curves of these 3 groups were compared. The right shift of the distribution curves of the PE groups was more pronounced at high pressure levels. The PE process seems to elevate the IOP particularly in eyes with a high IOP, which is in correspondence with hydrodynamical laws. At a certain IOP, the probability of having glaucomatous damage was higher in eyes with PE than in those without, indicating an increased vulnerability of PE eyes to an elevated IOP. PE may be a glaucoma risk factor also on its own, i.e. independent of the pressure elevation connected with this syndrome.

Relationship between asymmetry of visual field defects and intraocular pressure difference in an untreated normal (low) tension glaucoma population

The importance of intraocular pressure on the pathogenesis of optic disc damage in normal (low) tension glaucoma has been much debated. This paper looks at the interocular difference in intraocular pressure in an untreated group of 60 patients with normal (low) tension glaucoma. In addition it assesses whether any relationship exists in any one subject between the higher intraocular pressure and the more severe visual field defect. We found that this relationship occurred in 22% (13) of the subjects. In the other 78% (47) of this population no correlation could be found. The existence of such a sizeable subgroup suggests that patients with normal tension glaucoma may be divided into those where intraocular pressure level could be important in the pathogenesis of the visual field defect and a majority where this relationship is less likely.

Biostatistical evidence for two distinct chronic open angle glaucoma populations.

Twenty-six eyes of 26 patients with low-tension glaucoma and 34 eyes of 34 patients with high-tension glaucoma were studied. Fifty-one measurements were available on each patient, including visual field indices, finger blood flow measurements, as well as haematological, coagulation, and biochemical and rheological variables. Multivariate analysis revealed two statistically distinct groups of patients, with low and high tension glaucoma cases equally distributed in both. The smaller group (15 patients) showed a suggestion of vasospastic finger blood flow measurements, and had a high positive correlation between the mean deviation (MD) index of field severity and the highest intraocular pressure (r = 0.715, p = 0.0008). The second, larger group (45 patients) showed disturbed coagulation and biochemical measurements, suggestive of vascular disease, and had no correlation between the MD index and the highest intraocular pressure.

Low-pressure glaucoma and the concept of the IOP tolerance distribution curve.

Although glaucoma is considered to be caused by an elevated IOP, many eyes with an IOP within the normal range develop manifest glaucoma. The concept of an IOP tolerance distribution may clarify this paradox. The frequency of low-pressure glaucoma is a result of the constellation of the IOP distribution and the distribution of the IOP tolerance limit in the population. The low risk of glaucoma in the high normal IOP range is counteracted by the large number of eyes in this IOP range. It is possible to calculate the prevalence of glaucoma and the distribution of IOP in the untreated glaucoma population, resulting from different alternative distributions of IOP tolerance limit. Credible results were obtained by assuming a normal distribution of the IOP tolerance limit with an average = 26 mmHg and a standard deviation = 2.5 mmHg. In the development of glaucoma, the importance of the IOP relative to other factors, increases continually from low importance at low IOP to high importance at high IOP.