Glaucomatous Optic Disc Research Articles

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.

Open-angle glaucoma and systemic hypertension: the blue mountains eye study.

To assess whether systemic hypertension is associated with open-angle glaucoma (OAG) in an older population. The Blue Mountains Eye Study examined 3654 subjects aged 49 to 97 years. Hypertension was diagnosed from history in treated subjects or from systolic blood pressure (BP) > or=160 mm Hg or diastolic BP > or=95 mm Hg. OAG was diagnosed from congruous glaucomatous optic disc rim thinning and visual field loss, without reference to intraocular pressure (IOP) level. Ocular hypertension (OH) was defined when IOP was > 21 mm Hg in either eye, among persons without OAG. Hypertension was present in 45.7% of subjects, OAG in 3.0%, and OH in 5.2%. Hypertension was significantly associated with OAG, after adjustment for OAG risk factors including IOP, odds ratio (OR) 1.56, 95% confidence interval (CI) 1.01-2.40. This relation was strongest in subjects with poorly controlled treated hypertension (OAG prevalence 5.4%), compared with normotensive subjects (OAG prevalence 1.9%), independent of IOP (OR 1.88, CI 1.09-3.25). The population attributable risk for hypertension (20.4%) was higher than for other identified OAG risk factors. The prevalence of OH was 8.1% in subjects with poorly controlled treated hypertension (OR 1.81, CI 1.20-2.73) and 8.2% in untreated hypertension (OR 1.96, CI 1.31-2.95), compared with 4.2% in normotensive subjects. Hypertension, particularly if poorly controlled, appears related to a modest, increased risk of OAG, independent of the effect of BP on IOP and other glaucoma risk factors. However, we could not exclude nocturnal hypotensive episodes among treated subjects. Hypertension was also associated with OH, a relationship that could in part reflect the influence of BP on IOP.

Prevalence of open-angle glaucoma and ocular hypertension in Latinos: The Los Angeles Latino Eye Study

Objective To estimate age- and gender-specific prevalences of ocular hypertension and open-angle glaucoma (OAG) in adult Latinos. Design Population-based, cross-sectional study. Participants Six thousand three hundred fifty-seven Latinos 40 years and older from 6 census tracts in Los Angeles, California. Methods The study cohort consisted of all self-identified Latinos of primarily Mexican ancestry 40 years and older residing in 6 census tracts in La Puente, California. All participants underwent a complete ophthalmologic examination, including measurement of intraocular pressure (IOP), visual field (VF) testing using an automated field analyzer, and simultaneous stereoscopic fundus photography of the optic disc. Ocular hypertension was defined as IOP of >21 mmHg and the absence of optic disc damage or abnormal VF test results. Open-angle glaucoma was defined as the presence of an open angle and various criteria that included a glaucomatous VF abnormality and/or evidence of glaucomatous optic disc damage in at least one eye. Main outcome measures Prevalence of open-angle glaucoma and ocular hypertension. Results For the 6142 participants who underwent a complete ophthalmologic examination at the clinical center, the prevalence of OAG was 4.74% (95% confidence interval [CI], 4.22%–5.30%). The prevalence of ocular hypertension was 3.56% (95% CI, 3.12%–4.06%). The prevalences of OAG and ocular hypertension were higher in older Latinos than in younger Latinos ( P<0.0001). No gender-related differences in prevalences of OAG and ocular hypertension were present. The mean IOP, mean deviation, and mean vertical cup–disc ratio in persons with OAG were 17 mmHg, −9.6 decibels, and 0.6, respectively. Seventy-five percent of Latinos with OAG and 75% of Latinos with ocular hypertension were previously undiagnosed. Further, 17% of Latinos with OAG and 23% of Latinos with ocular hypertension had received treatment for “glaucoma.” Conclusion Our data suggest that the prevalence of OAG is high among Latinos of Mexican ancestry. The higher prevalence of OAG in older Latinos emphasizes the public health importance of providing eye care services for the early diagnosis and management of this condition in Latinos.

Association of magnetic resonance imaging of anterior optic pathway with glaucomatous visual field damage and optic disc cupping.

To investigate the association of magnetic resonance imaging (MRI) of anterior optic pathway with glaucomatous visual field damage and optic disc cupping. Twenty-three healthy volunteers (controls) and 31 glaucoma patients (14 with primary open angle glaucoma and 17 with normal tension glaucoma) were enrolled. All the participants showed no abnormal signs in their intracranial space and optic tract causing optic nerve atrophy and visual field defect, as confirmed by MRI. Multislice T1-weighted spin-echo imaging was performed in the sagittal plane followed by the coronal plane. MRI enabled the evaluation of the diameter of the optic nerve located in the retro-bulb space and the height of the optic chiasm in an observer-masked fashion. The MRI data were compared with the mean deviation (MD) score of the full threshold static visual field test and the optic cup-disc ratio (C/D ratio). The optic nerve diameter was significantly smaller in glaucoma patients (2.25 +/- 0.33 mm) than in controls (2.47 +/- 0.24 mm) and the height of the optic chiasm was significantly shorter in glaucoma patients (2.12 +/- 0.37 mm) than in controls (2.77 +/- 0.36 mm). The optic nerve diameter showed significant correlation with MD score (r = 0.547, P = 0.001) and C/D ratio (r = 0.407, P = 0.009). These correlations are similar to that between MD score and C/D ratio (r = 0.490, P = 0.001). The height of the optic chiasm showed significant correlation with MD score (r = 0.503, P = 0.01) and low correlation with C/D ratio (r = 0.339, P = 0.113). Glaucoma affects the anterior visual pathway anterogradely at least up to the optic chiasm, and these morphologic changes in the anterior visual pathway are correlated with glaucomatous optic nerve damage. MRI of the anterior visual pathway may be a good tool for evaluating glaucomatous damage objectively.

Magnification changes in scanning laser tomography.

It is important when evaluating glaucomatous optic disc progression in longitudinal images that image magnification remains unchanged. We studied the effect of changed lens power on magnification in scanning laser tomography. The relative contribution to magnification of axial length, eye-scanner distance, and image-to-image scaling was also assessed. A simulated optic disc in a model eye was imaged using the Heidelberg Retina Tomograph. Lens power was alterable by exchanging intraocular lenses (IOL) mounted at the lens plane of the eye to mimic changes in the crystalline lens. IOL power of +20.0D and axial length of 21.5 mm was compatible with emmetropia. The optic disc was imaged through IOLs differing in power (+16.0D to +25.0D) but with axial length kept constant. IOL power was then held constant and imaging was repeated for various axial lengths (17.5-23.5 mm). Model eye-scanner distance was varied with each test sequence. The distances between landmarks on the disc was measured before and after contour lines were exported. Image size varied with IOL power and axial length (r > 0.98; P < 0.0001), with the magnification effect of a +1D increase in lens power equivalent to a third the magnification effect of a 1-mm increase in axial length. Magnification tended to increase with myopia (IOL power > +20.0D) and was accentuated by longer eye-scanner distances. Image-to-image scaling corrected some magnification though this varied with ametropia. Changed lens power, axial length, and eye-scanner distance can affect the size of the optic disc in scanning laser tomography images. The exported contour line partly compensates for changed magnification.

Total plasma homocysteine and primary open-angle glaucoma

PurposeTo evaluate total plasma homocysteine (tHcy) levels in patients diagnosed with primary open-angle glaucoma (POAG) and normal subjects. DesignCase-control study. MethodsThis study involved 55 POAG patients, 16 patients with secondary open-angle glaucoma or angle-closure glaucoma (non-POAG group), and 39 control healthy subjects undergoing ocular surgery. All glaucoma patients had characteristic glaucomatous optic disk damage and visual field loss. Fasting tHcy concentrations of all study participants were determined using high-performance liquid chromatography. Analysis of variance was used to compare homocysteine levels among the three diagnostic groups, and multivariate analysis was conducted to assess the associations between tHcy and diagnostic group, age, gender, smoking status, systemic hypertension, hyperlipidemia, and cardiovascular or cerebrovascular disease. ResultsMean ± standard deviation of tHcy levels in POAG individuals, non-POAG patients and control subjects was 14.90 ± 6.45 μmol/l, 14.30 ± 4.35 μmol/l, and 14.81 ± 4.56 μmol/l, respectively (P = .93; ANOVA). No statistically significant difference was found in the proportion of patients with abnormal tHcy levels among the three diagnostic groups. In multivariate analysis, only age and positive smoking status were significantly correlated with total plasma homocysteine levels. ConclusionNo significant difference was found in plasma homocysteine levels among POAG patients and normal control individuals.

Statistical and neural net methods for automatic glaucoma diagnosis determination

Abstract Two new computer diagnostic methods for the automatic determination of glaucoma diagnosis are presented and compared in this paper: the statistical method and the neural net method. Both introduced methods evaluate colour glaucomatous changes within the optic disc area. The mentioned colour changes are numerically represented using a suitable image analysis process. Next, the investigated eye is classified to three defined glaucoma-risk classes with different reliability of the diagnosis determination. The verification and the reliability comparison of both studied methods are performed by virtue of the application of this methods to a set of normal healthy optic disc images and a set of glaucomatous optic disc images.

Intraocular pressure asymmetry and undiagnosed open-angle glaucoma in an older population

PurposeTo quantify prevalence of asymmetric intraocular pressure (IOP) and assess associations with undiagnosed open-angle glaucoma. DesignPopulation-based cross-sectional study. MethodsParticipants underwent applanation tonometry. Intraocular pressure asymmetry was defined for differences ≥ 3 mm Hg; open-angle glaucoma was diagnosed if glaucomatous optic disk and field changes were congruous. Analyses excluded subjects using glaucoma medication, known glaucoma, pseudoexfoliation, and cataract surgery. ResultsIntraocular pressure asymmetry was present in 5.1% of subjects and was greater for patients older than 70 years (6.2%). Of subjects with maximum IOP > 21 mm Hg, IOP asymmetry was present in 41.1%. Undiagnosed open-angle glaucoma was more frequent among subjects with (4.8%) than without (1.2%) IOP asymmetry. This relationship remained significant for maximum IOP ≤ 21 mm Hg. ConclusionsIntraocular pressure asymmetry may be a useful sign of undiagnosed glaucoma in subjects without elevated IOP.

Open-angle glaucoma and systemic thyroid disease in an older population: The Blue Mountains Eye Study

To assess whether thyroid disease is independently associated with open-angle glaucoma (OAG), using history of thyroid disease and current thyroxine use. The Blue Mountains Eye Study examined 3654 persons, aged 49-97 years. Interviewers collected self-reported history of diagnosis and treatment for thyroid disease. Eye examinations included applanation tonometry, stereoscopic optic disc photography and automated perimetry. OAG was diagnosed from the presence of matching typical glaucomatous field changes and optic disc cupping, independent of intraocular pressure. Associations between thyroid disease (history and treatment) and OAG were assessed in a multivariate model. Of 324 participants (8.9%) reporting history of thyroid disease, 147 (4.0%) were currently using thyroxine. Although we could not accurately categorize the thyroid disorder for all cases, current use of thyroxine suggests a prior hypothyroid state. All thyroid disease subgroups affected women more frequently than men, P=0.001. OAG was diagnosed in 108 subjects (3.0%) and was more frequent in those reporting past thyroid disease (4.6 vs 2.8%). This relationship was not statistically significant after adjusting for potential confounders, multivariate odds ratio (OR) 1.6; 95% confidence interval (95% CI) 0.9-2.9. OAG was significantly more frequent, however, in subjects reporting current thyroxine use (6.8 vs 2.8%), multivariate OR 2.1; 95% CI 1.0-4.4, or history of thyroid surgery (6.5 vs 2.8%), multivariate OR 2.5; 95% CI 1.0-6.2. This population-based study suggests that thyroid disease, indicated by current thyroxine use or past thyroid surgery, could be independently related to OAG.

Glaucomatous optic disc hemorrhages on confocal scanning laser tomographic images.

To evaluate the detectability of glaucomatous optic disc hemorrhages by confocal scanning laser tomography. The study included 73 eyes of 63 patients, who consecutively showed optic disc hemorrhages on 15 degrees color optic disc photographs taken at baseline or during follow-up examinations and for whom confocal scanning laser tomographic images were additionally available. Of the total number of 92 observed hemorrhages, 51 hemorrhages extended into the parapapillary region and 41 hemorrhages were restricted to the intrapapillary region. The scanning laser tomographic images were searched for the disc hemorrhages already seen on the conventional disc photographs. Using the reflectivity images, 29 (32%) hemorrhages were detected on the scanning laser tomographs. None of the hemorrhages restricted to the intrapapillary region could be seen on the scanning laser tomographs. By evaluating each of the 32 single images of the scanning laser tomographic image series, 44 (48%) of the hemorrhages were identified on at least one single image. The detectability of disc hemorrhages on the scanning laser tomographs depended significantly on their extension into the parapapillary region or their intrapapillary location. Detectability of disc bleedings was statistically independent of the disc quadrant where the hemorrhage was located, width of the bleeding, size of the optic disc, neuroretinal rim, parapapillary atrophy, and type of glaucoma. Confocal scanning laser tomography is not very suitable for detection or documentation of optic disc hemorrhages in patients with glaucoma.

Clinical agreement among glaucoma experts in the detection of glaucomatous changes of the optic disk using simultaneous stereoscopic photographs

Purpose To evaluate the clinical agreement in the detection of optic disk changes in patients with glaucoma using simultaneous stereophotographs. Design Masked-observer variability study. Methods Ten glaucoma specialists examined pairs of simultaneous stereophotographs of glaucomatous and control optic disks to determine whether there were changes compatible with progression of glaucomatous damage. Results Intraobserver agreement had a kappa value ranging from 0.55 to 0.78. Interobserver agreement among the glaucoma specialists had a kappa value ranging from 0.34 to 0.68. Conclusion Clinical examination of stereophotographs to detect optic disk changes in glaucoma patients has limitations associated with suboptimal reproducibility.

Relationship of optic disk topography and visual function in patients withlarge cup-to-disk ratios

Purpose To determine if topographic differences exist between large cup-to-disk ratio (C/D) eyes with standard achromatic automated perimetry (SAP) abnormalities and those with only short-wavelength automated perimetry (SWAP) abnormalities. Design Cross-sectional study. Methods The setting was a referral university-based clinical practice. We selected one eye of 72 patients with a vertical C/D of at least 0.8 by ophthalmoscopy. Patients performed SWAP, SAP, and confocal scanning laser ophthalmoscopy. We compared optic disk topography in eyes with and without visual field abnormalities and controlled for the influence of disk area. Results Disk area was a confounder of many topographic measures. After controlling for disk area, eyes with abnormal SAP had differences in rim volume, cup shape, rim area, retinal nerve fiber layer thickness, and retinal nerve fiber layer cross-sectional area when compared with eyes with normal SAP ( P < .05). Rim volume and rim area were different in the SWAP comparison ( P < .05). Conclusions Investigators should control for disk area when evaluating topographic measures by confocal scanning laser ophthalmoscopy. In eyes with a large C/D, optic disk topography is more glaucomatous in eyes with SAP abnormalities than in those with only SWAP abnormalities. Eyes with large C/D and only SWAP abnormalities may have fewer glaucomatous optic disk changes than such eyes with SAP abnormalities. This indicates that SWAP is likely to correspond to abnormalities in optic disk topography at an earlier stage of glaucomatous optic neuropathy than SAP. Therefore, clinicians should consider SWAP testing in glaucoma suspects to detect glaucomatous visual field loss at an earlier stage of structural loss.

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.

A statistical model for the evaluation of sensory tests in glaucoma, depending on optic disc damage.

To analyze the sensitivity of various sensory tests adjusted for glaucomatous optic disc damage. In a cross-sectional study, the results of testing of 196 control subjects (age range, 18-69 years) and 308 patients with chronic open-angle glaucoma (age range, 18-70 years) were included. The perimetric mean defect (MD), a temporal contrast sensitivity test (TCS), a spatiotemporal contrast sensitivity test (STCS), the peak time of a blue-on-yellow visual evoked potential (BYVEP), and the amplitude of a pattern-reversal electroretinogram (PERG) were evaluated by a specific logistic regression model. This model included glaucomatous damage, quantified by neuroretinal rim area corrected for disc size, as a covariate of sensitivity. Sensitivity of diagnostic tests increased for all procedures with increasing loss of neuroretinal rim area. With progressing optic disc damage, MD and STCS showed higher sensitivity than did TCS. BYVEP showed a higher sensitivity than PERG in all disease stages. In general, the psychophysical tests were more sensitive than the electrophysiological ones. The specific model used in this study was an appropriate tool to analyze the sensitivity of several sensory glaucoma tests in relation to disease stage. Moreover, tests that were more sensitive in early disease stages (TCS) and others that were more sensitive in more advanced stages (MD, STCS) were identified.

Reproducibility of evaluation of optic disc change for glaucoma with stereo optic disc photographs

Purpose To determine the reproducibility of the assessment for glaucomatous change in serial optic disc stereo-slides. Design Masked interobserver variability study. Participants Serial optic disc stereo-slides from 40 patients. Methods Three independent ophthalmologists evaluated for change a set of two serial 20° optic disc color stereo-slides of 40 patients. This test set was not from European Glaucoma Prevention Study (EGPS) patients. Each observer performed two evaluations at least 30 days apart and was masked from the temporal sequence of the slides and his or her previous evaluation. Each patient was graded as changed or stable by two-out-of-three agreement. A κ statistic was used to calculate the intra- and interobserver reproducibility as well as the assignment reproducibility (first consensus versus second consensus). The same procedure was followed to test the reproducibility when another experienced ophthalmologist was added to one of the three reading centers. Main outcome measures Reproducibility in evaluating glaucomatous optic disc change. Results The intraobserver reproducibility (95% confidence interval [CI]) in the evaluation of change ranged between 0.79 (0.45–1.14) and 1.00 (0.69–1.31). The interobserver reproducibility (95% CI) in the evaluation of change ranged between 0.45 (0.15–0.75) and 0.75 (0.44–1.06). The assignment reproducibility (first consensus versus second consensus in the evaluation of change) between the senior EGPS readers was 0.94 (0.63–1.25). The assignment reproducibility when another experienced ophthalmologist replaced one of the readers was 0.94 (0.63–1.25). Conclusions The assignment reproducibility of three expert readers looking for glaucomatous change in serial optic disc stereo-slides was excellent. It remained so when one of the three experts was replaced by another experienced reader.

Structure and function evaluation (SAFE): II. comparison of optic disk and visual field characteristics

Purpose To evaluate the relationship between glaucomatous structural damage to the optic nerve and development of visual field loss with standard automated perimetry (SAP) and short wavelength automated perimetry (SWAP). Design Cohort study. Methods Patients with elevated intraocular pressure and normal SAP visual fields were enrolled in this prospective study. Stereo optic disk photographs, SAP, and SWAP visual fields were obtained annually over a period of 4 or more years. Trained readers evaluated baseline and follow-up optic disk photographs for evidence of glaucomatous damage. Standard automated perimetry and SWAP examinations were evaluated according to previously validated criteria for development of confirmed visual field changes. Results Two-hundred ninety-five subjects (479 eyes) were enrolled. Following masked assessment of stereo photographs by an optic disk reading center, 272 of the 479 eyes were judged to have glaucomatous optic neuropathy at the time of study entry. Depending on the criteria employed, approximately 10% to 17.5% of all eyes developed confirmed visual field loss for SAP (conversions). Of the conversions, 75% to 80% had baseline glaucomatous optic disk damage, whereas normal and glaucomatous optic disks were equally divided (50%) among the nonconversion eyes. This difference was statistically significant ( P < .003). Depending on the criteria employed, 4% to 12% of the eyes had confirmed SWAP deficits at baseline, and 4% to 8% developed confirmed SWAP defects at a follow-up examination. There was a greater percentage of eyes with a glaucomatous optic neuropathy in the group with SWAP deficits (75%–100%) than for those eyes in which SWAP remained normal (45%–60%). Some of these differences were statistically significant ( P < .05). Conclusions A strong relationship exists between glaucomatous optic disk damage at study entry and the subsequent development of a confirmed glaucomatous SAP visual field defect. A higher percentage of glaucomatous optic disks were also found in patients with SWAP deficits at baseline and in those who later developed SWAP deficits. These findings support the premise that a glaucomatous optic disk is predictive of the subsequent development of glaucomatous visual field loss.

Combined use of frequency doubling perimetry and polarimetric measurements of retinal nerve fiber layer in glaucoma detection

Purpose The aim of this study was to evaluate the diagnostic usefulness of the combined use of frequency-doubling technology (FDT) perimetry and polarimetry of the retinal nerve fiber layer. Design Cross-sectional study. Methods Seventy ocular hypertensive patients (normal optic disk and standard perimetry, elevated intraocular pressure [>21 mm Hg]), 59 patients with “preperimetric” open-angle glaucoma (glaucomatous optic disk atrophy, elevated intraocular pressure [>21 mm Hg], no visual field defect in standard perimetry), 105 patients with “perimetric” open-angle glaucoma (glaucomatous optic disk atrophy and clearly marked visual field defect), and 73 control subjects had FDT screening (protocol: C-20-5) and polarimetric measurements (GDx). Criteria for exclusion: optic disks larger than 4 mm 2, media opacities, patients younger than 33 years or older than 66 years. None of the subjects had earlier FDT perimetry. One eye of each patient and control subject entered the statistical evaluation. Database and statistical software were used for case-wise recalculation of all missed localized probability levels to create a FDT screening score. Results At a predefined specificity of 94.5% in control eyes, discrimination between “perimetric” glaucoma and normal subjects is superior using the FDT perimetry (sensitivity = 84.8%) in comparison to polarimetry (sensitivity = 63.8%), whereas sensitivity is similar with both methods in “preperimetric” patients (GDx, FDT: 25.4%). In several cases, patients classified as glaucomatous by the GDx are not the same patients as identified by the FDT perimetry. Therefore, a two-dimensional discrimination analysis can increase correct positive classification. Using a linear combination of the present FDT screening score and polarimetry (“the number”), 92.4% of “perimetric” glaucoma eyes and 44.1% of “preperimetric” glaucoma eyes have been classified as glaucomatous. Conclusion Joint usage of polarimetry and FDT perimetry indicate that a combination of different techniques which can uncover different glaucoma properties, might be helpful in early glaucoma detection.

Relationship between intraocular pressure and systemic health parameters in a Korean population

This study aimed to evaluate the relationship between intraocular pressure (IOP) and age and obesity, adjusted for systemic health parameters such as sex and mean blood pressure, in a Korean population. A total of 13 212 healthy participants underwent automated multiphasic tests, including tonometry, automated perimetry, fundus photography, blood pressure and body mass index (BMI). Six age groups were used, divided by decades ranging from 20-29 years to 70+ years. The association between IOP and systemic health para-meters was examined using cross-sectional analysis. The median age of participants was 47.6 years (range 20-84 years), and 6684 (50.6%) of participants were men. The mean IOP of participants was 15.5 mmHg. The mean IOP, blood pressure and BMI values were significantly higher in men than in women (P < 0.05). The overall prevalence of ocular hypertension, defined as IOP >21 mmHg without signs of glaucomatous visual field loss or optic disc damage, was 6.1% in men and 2.5% in women. Intraocular pressure was associated with mean blood pressure, sex, age and BMI by multiple regression analysis (P < 0.05). The relationship between IOP and age adjusted for sex, mean blood pressure and BMI had a significantly negative tendency for both sexes (P < 0.05). Body mass index had a significantly positive relation with IOP after controlling for age, sex and mean blood pressure in men (P < 0.05), but not in women. In this Korean population, after multiple adjustment, IOP was found to decrease with age and to increase with BMI in men.

The structure-function relationship in eyes with glaucomatous visual field loss that crosses the horizontal meridian.

To evaluate the relationship between visual field loss and glaucomatous optic discs in eyes in which field loss spreads across the horizontal meridian. Ninety-six patients with glaucoma (9 advanced, 60 moderate, and 27 early) with 2 successive abnormal fields were included. Standard achromatic automated perimetry defects were identified with a nerve fiber bundle map to identify abnormal sectors. Crossover was present if the superior and inferior sectors at the horizontal meridian (nasal, central, or temporal) were both abnormal. Optic disc damage was assessed by masked grading of simultaneous stereophotographs. Only 30% (29) of glaucomatous eyes showed crossover, and only 2 of those eyes had early loss. The most frequent pattern of visual field loss (41% of eyes) was single hemifield damage with defects in contiguous sectors. Regardless of the pattern or severity of visual loss, most eyes (66 [69%] of 96) had both superior and inferior optic disc damage. Early glaucomatous visual field loss rarely crosses the horizontal meridian, but defects in both hemifields at the horizontal meridian are more common in more advanced field loss. In 26 (90%) of 29 eyes with crossover, it could be explained by changes at the optic nerve head.

Multifocal ERG with 30 Hz flicker stimulation in glaucoma patients and normal probands

It was the aim of the present study to investigate the value of multifocal ERG with 30 Hz flicker stimulation for glaucoma diagnosis. Multifocal ERGs with 30 Hz flicker stimulation were recorded with a mean luminance of 50 cd/m2 and a contrast of 99% from the central 60 degrees of the retina which were stimulated by 61 hexagons. From 30 patients with primary and secondary open-angle and low-tension glaucomas with reproducible visual field losses and glaucomatous optic disc atrophy and 21 normal subjects, one eye was included in the study. The first harmonic wave, the basewave and the ratio of these two parameters were ana-lysed. The responses of seven neighbouring hexagons were averaged for the intraocular comparison between areas with and without perimetric defects and for the comparison between glaucomas and normal subjects. In the glaucoma group, the ratio of the first harmonic wave and the basewave was significantly lower in an area within a perimetric defect than outside the defect (p < 0.001) when compared intraocularly. The extent of ERG changes however did not correlate with the extent of perimetric defects. Comparing the glaucoma with the normal group, the ratio of the first harmonic and the basewave was significantly lower in an area within the perimetric defect in the glaucoma group than in corresponding areas of the normal group (p = 0.002). The first harmonic and the basewave did not differ significantly. These results show that the method is not appropriate to objectively indicate visual field losses although it statistically separates glaucomas from normal subjects.