Amphetamine increases extracellular concentrations of glutamate in the prefrontal cortex of the awake rat: a microdialysis study

OBJECTIVE: To determine if motion automated perimetry can identify early glaucomatous visual field defects in patients with suspected glaucoma (by disc), those with ocular hypertension, and those with primary open-angle glaucoma. METHODS: Motion automated perimetry, a foveally centered motion test, and standard visual field tests were conducted on one randomly selected eye of normal patients (n = 38), patients with suspected glaucoma (by disc) (n = 28), patients with ocular hypertension (n = 18), and patients with primary open-angle glaucoma (n = 21). Subjects' performance on both motion tests were compared with their performance on standard perimetry. RESULTS: Perimetric motion thresholds significantly distinguished the groups (P< or =.001), while the foveally centered motion test was unable to separate them (P< or =.32). Of the total patients, 90.5% of those with glaucoma, 39.3% of those with suspected glaucoma, 27.8% of those with ocular hypertension, and 5.3% of the normal subjects had abnormal results on motion automated perimetry testing. Perimetric motion thresholds were significantly correlated with standard visual field thresholds (P< or =.001). CONCLUSION: Motion automated perimetry identifies visual field defects in patients who already show standard visual field loss as well as in a moderate percentage of those with suspected glaucoma and ocular hypertension, indicating that the testing of discrete locations might be necessary for increased diagnostic utility.     

Diabetes in primary open-angle glaucoma patients with inferior visual field defects

We reviewed the charts of 144 randomly selected patients with primary open-angle glaucoma who had Aulhorn's stage 1, 2, or 3 visual field defects to investigate whether primary open-angle glaucoma patients with predominantly inferior visual field defects had a higher prevalence of diabetes mellitus than primary open-angle glaucoma patients without such visual field defects. Of the 59 patients with mainly inferior visual field defects in one or both eyes, 19 (32%) had diabetes mellitus, while 11 of 85 (13%) patients without such defects had diabetes mellitus. This difference was statistically significant (P = 0.0096). These results suggest that primary open-angle glaucoma patients with predominantly inferior visual field defects in one or both eyes are more likely to have diabetes and that such patients with no known history of diabetes may benefit from glucose tolerance testing to detect occult impaired glucose tolerance or diabetes mellitus.     

Influence of axial length on visual field defects in primary open-angle glaucoma

With the high frequency of myopia in Taiwan, potential complications or associated conditions, such as glaucoma, are of great concern. To investigate the role of axial length in glaucoma, we enrolled 307 primary open-angle glaucoma (POAG) patients from 1986 through 1996. For the control group, 124 persons were recruited from a survey of a non-glaucoma population and the Ophthalmology Out-patient Department of the National Taiwan University Hospital. Routine eye examination, stereophotography of the optic disc, automated visual field tests, and A-scan ultrasonography were performed on each patient. The Glaucoma Hemifield test was used for analysis of visual field results. The mean axial length was longer in the POAG group than in the control group, especially in the younger age groups (40-59 yr). The POAG group was divided into a short-axial-length (SAL, axial length < 26 mm) group and a long-axial-length (LAL, axial length > or = 26 mm) group. Both subgroups had the deepest visual field defects in the upper and lower nasal areas. The LAL group had deeper visual field defects and the defects were more frequently involved in all sectors analyzed than the SAL group defects. The upper visual field had deteriorated more in the SAL group, whereas the depth of scotoma was similar in the upper and lower hemifields in the LAL group. Our results support the idea that glaucoma patients have a longer axial length than people without glaucoma, and that visual field defects are more pronounced in patients with LAL than in those with SAL.     

Short-wavelength color visual fields in glaucoma suspects at risk

Glaucoma suspect eyes were seen during a five-year study on color visual fields that used a 440-nm test on a bright-yellow background (96 normal eyes, 55 suspect eyes, and 110 eyes that developed glaucoma). The predictive ability of the test was assessed in 25 eyes followed up for more than one year, five of which developed glaucoma. These five eyes and those at high risk showed higher mean defect (P < .0001) and number of defective points (P < .0001) than the other suspect groups, which were not significantly different from normal eyes. The mean defects (+/- standard deviations) and average number of defective points were 1.4 +/- 2.3 dB with 8.9 points (low-risk eyes), 1.1 +/- 1.2 dB with 8.0 points (medium-risk eyes), 6.7 +/- 2.8 dB with 27.7 points (high-risk eyes), and 9.3 +/- 1.8 dB with 39.4 points (eyes that developed glaucoma). Normal eyes had an average of 3.4 defective points. These results were similar when all 55 suspect eyes were analyzed. Color visual fields identify early functional loss in eyes at greatest risk for primary open-angle glaucoma.     

Erythrocyte sodium-lithium countertransport activity and total body insulin-mediated glucose disposal in normoalbuminuric normotensive type 1 (insulin-dependent) diabetic patients

PURPOSE: To assess the potential of a clinical method of optic disc measurement in the detection of early neuroretinal rim loss in glaucoma. METHODS: A method of disc biometry based on indirect ophthalmoscopy was used to estimate disc and neuroretinal rim areas in 81 ocular hypertensive eyes of 43 patients and in 28 fellow eyes with normal visual fields of patients with unilateral visual field loss from primary open-angle glaucoma. The results were compared with those from age-matched visually normal patients. RESULTS: Neuroretinal rim area was significantly smaller in both hypertensive and fellow eye groups compared with controls (P < 0.0001; P = 0.0009). Disc area also was smaller in both groups (P = 0.0034; P = 0.046); however, this was inadequate to explain the differences in rim area, which, when corrected for disc size, were still highly significant (P < 0.0001; P = 0.0001). CONCLUSION: The differences in neuroretinal rim area observed are likely to indicate that a proportion of the eyes studied had suffered a reduction of neuroretinal rim area, which was measurable by this method at a stage before the development of demonstrable visual field loss.     

Abnormal motion displacement thresholds are associated with fine scale luminance sensitivity loss in glaucoma

This study tests the hypothesis that abnormal motion displacement thresholds coexist with scotomas on a finer spatial scale than is measurable by conventional Humphrey perimetry. Eighteen patients with primary open angle glaucoma in one eye, and 18 age matched normal controls underwent motion displacement threshold testing and high spatial resolution perimetry. The motion displacement thresholds were significantly elevated in the glaucoma eyes, in 73% this exceeded normal limits. Ten glaucoma eyes had normal Humphrey 24-2 field nearest the motion test site: of these seven had abnormally elevated motion displacement thresholds and six had fine scale threshold depressions detected with high spatial resolution perimetry. This result suggests that glaucomatous elevations of motion displacement threshold may be present in areas of normal Humphrey 24-2 field, and this may coexist with measurable scotomas beyond the resolution of conventional Humphrey perimetry in some, but not all patients.     

Visual evoked potential assessment of the effects of glaucoma on visual subsystems

The purpose of this study is to test the hypothesis that glaucoma leads to selective deficits in parallel pathways or channels. Sweep VEPs were obtained to isolated-check stimuli that were modulated sinusoidally in either isoluminant chromatic contrast or in positive and negative luminance contrast. Response functions were obtained from 14 control subjects, 15 patients with open-angle glaucoma, and seven glaucoma suspects. For all three groups of subjects we found characteristic differences between the VEP response functions to isoluminant chromatic contrast stimuli and to luminance contrast stimuli. The isoluminant chromatic stimulus conditions appeared to favor activity of the P-pathway, whereas the luminance contrast stimuli at low depths of modulation favored M-pathway activity. VEP responses for patients with OAG were significantly reduced for chromatic contrast and luminance contrast conditions, whereas VEP responses for glaucoma suspects were significantly reduced only for the 15-Hz positive luminance contrast condition. Our results suggest that both M- and P-pathways are affected by glaucoma.     

Tuberculosis control in the New York State Department of Correctional Services: a case management approach

AIM: To determine if impaired motion sensitivity is a significant predictor of subsequent field loss in glaucoma suspects. METHOD: A population based prospective study; a 5 year follow up of all glaucoma suspects who had been identified from a population based random sample survey in the west of Ireland. 78 glaucoma suspects whose visual field function was annually measured by Henson CFS 2000 and for whom data on family history of glaucoma, ocular status, and motion impairment had been recorded. Visual field loss was defined as Henson visual field survival score of 94 or less. RESULTS: 18 people developed visual field loss in at least one eye. Motion impairment at baseline was associated with a 2-18 times greater risk of development of the visual field loss (p < 0.001). This association was independent of sex, family history of glaucoma, intraocular pressure, and C/D ratio at baseline. The Cox's proportional hazards regression analysis confirmed the above results after adjustment for age and the C/D ratio. CONCLUSION: Motion impairment is an independent predictor of visual field loss in glaucoma suspects, although it is not clear how long motion impairment precedes visual field loss.     

Plasma cortisol suppression test used to predict the development of primary open-angle glaucoma

Forty patients classified as high responders (GG) to dexamethasone testing (intraocular pressure greater than 31 mm Hg) without visual field loss were subjected to plasma cortisol suppression testing. After a five-year follow-up adequate data were available on 35 patients. Eighteen responded to 1.0 mg of dexamethasone-diphenylhydantoin suppression testing in a similar fashion to patients with primary open-angle glaucoma while 17 responded in a similar fashion to subjects classified as low (NN, intraocular pressure less than 20 mm Hg) and intermediate (NG, intraocular pressure 20 to 31 mm Hg) responders to dexamethasone testing. Eight of the 35 patients developed glaucomatous visual field loss during the follow-up period. These eight patients were not more sensitive to suppression of plasma cortisol than the 27 patients maintaining normal visual fields. Thus, plasma cortisol suppression testing failed to predict the development of primary open-angle glaucoma in GG responders.     

Newer visual function tests in the evaluation of glaucoma

Conventional visual field testing, with a uniform white-on-white stimulus, is used routinely to diagnose and follow patients with chronic open-angle glaucoma. Many investigators, however, believe that conventional perimetry may not detect the earliest visual dysfunction in patients with chronic open-angle glaucoma. Consequently, much research has been performed over the past decade to develop a visual function test which might diagnose chronic open-angle glaucoma earlier than conventional perimetry. This review discusses the mechanisms, clinical studies and the current usefulness of the most common new visual function techniques. These tests attempt to detect early glaucomatous visual loss, generally by placing the visual system under stress and by minimizing the influence of extensive functional redundancy in the retinal ganglion cell network due to widely overlapping receptive fields. Success of new visual function tests depends on the specificity and the sensitivity of the instrument, excellent patient acceptance, short test duration, standardization of techniques, and limited expense. In addition to searching for newer visual function tests to evaluate glaucoma, we should continue efforts to improve the diagnostic capability and shorten the test duration of conventional perimetry.     

Effect of mitomycin C on aqueous humor flow, flare and intraocular pressure in eyes with glaucoma 2 years after trabeculectomy

BACKGROUND: The purpose of this study was to determine the intraocular pressure (IOP), aqueous humor flow, flare and ocular side effects in eyes with a history of hypotony after trabeculectomy with adjunctive mitomycin C (MMC). METHODS: Thirty-six eyes with primary or secondary open-angle glaucoma and IOP < or = 8 mmHg during the postoperative period were studied 745 +/- 315 days after surgery. MMC (0.2 or 0.5 mg/ml) was applied to the episclera with a cellular sponge. Flare was studied with the Kowa Laser Flare Meter 500. Aqueous humor flow was measured in the afternoon (Fluorotron Master II). IOP, visual fields and best corrected visual acuity were also examined. Twenty-two contralateral eyes without surgical intervention served as controls. RESULTS: The mean age of patients was 44.5 +/- 16.8 years. The mean IOP was significantly lower in the MMC group than in the control group: 9.6 +/- 6.4 mmHg vs 18.0 +/- 13.6 mmHg at 2 years (P < 0.001). Aqueous flow was significantly lower in subjects treated with MMC than in controls (P < 0.001). The flare values were significantly higher in the MMC-treated group, with a mean of 12.0 +/- 7.7 photon counts/ms, than in the control group, mean 7.9 +/- 4.6 photon counts/ms (P < 0.019). CONCLUSION: Our data suggest that MMC is a useful ocular hypotensive agent which seems to participate in a change in aqueous humor dynamics when applied topically as an aqueous solution.     

Analysis of the systemic corticosteroid sensitivity of patients with primary open-angle glaucoma

Patients with primary open-angle glaucoma have an ocular and systemic sensitivity to corticosteroids. We adapted a cellular assay that used peripheral blood lymphocytes to detect this corticosteroid sensitivity in vitro in a microtiter assay. It reduced the time, cost, and amount of blood required to examine a patient. We examined ten subjects on three separate days and demonstrated that the reliability of one 50% inhibitory concentration was about 76%. We then studied 25 patients with primary open-angle glaucoma and 25 control subjects using this in vitro assay. The patients with primary open-angle glaucoma were significantly more sensitive to corticosteroids than the control subjects (P less than .001).     

Visual field damage proximal to fixation in normal- and high-tension glaucoma eyes

To compare in more detail the central visual field damage in normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) eyes, a pointwise inner-group comparison of the data obtained with the Humphrey 10-2 was carried out in 68 NTG cases with maximum intraocular pressure (IOP) of < or = 21 mmHg and 62 HTG cases with maximum IOP of > or = 25 mmHg. All eyes had the usual field defects, with a mean deviation of > or = -15 dB (MD, STATPAC). Age, refraction and MD were matched between the two groups. Total deviation (TD, STATPAC), the difference between the measured threshold and the age-corrected normal reference at each test point of the 10-2 program, was used for pointwise inter-group comparisons. The data were analyzed with Wilcoxon rank-sum test and logistic discriminant analysis. The latter method was also applied to the data of the 30-2 program to confirm the results obtained with the 10-2 program. The comparisons using the different methods and programs gave consistent results. For a given amount of overall visual field damage in the two types of glaucoma, a superior arcuate area extending down to the horizontal meridian just nasal to the fixation point was significantly more depressed and an area inferior to the horizontal meridian and inferior temporal to the fixation point significantly less depressed in NTG eyes. HTG eyes were significantly more diffusely damaged in the central 10-degree visual field. NTG and HTG may have unique patterns of central visual field damage. These differences may implications in following NTG patients and studying the pathogenesis of this glaucoma.     

Effect of vitamin B6 on the side effects of a low-dose combined oral contraceptive

PURPOSE: To evaluate acquired color vision defects in glaucoma patients and glaucoma suspects. MATERIAL AND METHODS: 52 subjects (102 eyes) divided into four groups (with primary open angle glaucoma, normal tension glaucoma, ocular hypertension and with glaucoma-like optic disc) were examined with the IF-2 All-Color Anomaloscope. In all cases both the red-green equation of Rayleigh and the blue-green equation of Moreland were tested and three variables were determined: setting (matching) range (SR), calculated mid point (matching mid point) (CMP) and anomalous quotient (AQ) as compared to control group. RESULTS: No significant changes were found in the variables of the Rayleigh equation. However, in the blue-green equation SR was significantly enlarged in all tested groups and CMP was significantly shifted towards the short wavelength end of the match in first three groups. These results indicate a diminution of the color discriminating sensitivity in the short wavelength half of the visible spectrum and diminution of the blue cone sensitivity in glaucoma patients as well as in ocular hypertension (p < 0.001). In patients with glaucoma-like optic disc the setting range was enlarged in less degree (p < 0.01) without changes in the remaining variables (p > 0.05) what may be indicative of early stage of disease before the perimetric changes. CONCLUSION: Blue-green colour vision testing with the anomaloscope may serve as an additional test in the diagnostics of glaucoma. Glaucoma suspects with blue colour vision disturbances require the most careful investigation and if need be the recommendation of early treatment.     

Risk factors for noncompliance with glaucoma follow-up visits in a residents' eye clinic

OBJECTIVE: This study aimed to identify factors associated with compliance with glaucoma follow-up visits. DESIGN: Computer records of a university residents' eye clinic were reviewed to identify a random sample of all persons who had an examination with International Classification of Disease (ICD) 9 coding (ICD9) for glaucoma suspect or glaucoma during a 2-year period (1991-1993) to undergo telephone interview. PARTICIPANTS: Those who were seen at least every 6 months regardless of earlier return instructions were defined as compliant with follow-up (controls, n = 362). Those who had any lapse between visits of longer than 6 months were defined as noncompliant (cases, n = 362). RESULTS: Interviews were completed for 196 cases and 242 controls. Noncompliant persons were significantly more likely to be suspects for glaucoma rather than to have definite glaucoma and to be dissatisfied with waiting time in the clinic (29.1% vs. 17.8%, P < 0.005) and to state that they did not take their glaucoma medications as prescribed (25.4% vs. 13.4%, P < 0.004). They also were less likely to have been prescribed eyedrop medication. A high percentage of both patients and controls knew that glaucoma can lead to blindness (85.2% and 88.4%, respectively). The most common reasons patients gave for not keeping follow-up visits were the perception that their eye problem was "not serious enough," the cost of examinations, and that the doctor did not tell them to come back. CONCLUSION: Compliance with follow-up visits for glaucoma is associated with markers for early disease. Attempts to improve compliance might focus on improved communication of the seriousness of the disease and improvements in clinic waiting time.     

Unilateral testing of utricular function

PURPOSE: To examine acquired pit of the optic nerve as a risk factor for progression of glaucoma. METHODS: In a retrospective longitudinal study, 25 open-angle glaucoma patients with acquired pit of the optic nerve were compared with a group of 24 open-angle glaucoma patients without acquired pit of the optic nerve. The patients were matched for age, mean intraocular pressure, baseline ratio of neuroretinal rim area to disk area, visual field damage, and duration of follow-up. Serial optic disk photographs and visual fields of both groups were evaluated by three independent observers for glaucomatous progression. RESULTS: Of 46 acquired pits of the optic nerve in 37 eyes of 25 patients, 36 pits were located inferiorly (76%) and 11 superiorly (24%; P < .001). Progression of optic disk damage occurred in 16 patients (64%) in the group with acquired pit and in three patients (12.5%) in the group without acquired pit (P < .001). Progression of visual field loss occurred in 14 patients (56%) in the group with acquired pit and in six (25%) in the group without pit (P=.04). Bilateral acquired pit of the optic nerve was present in 12 patients (48%). Disk hemorrhages were observed more frequently in the group with acquired pit (10 eyes, 40%) compared with the group without pit (two eyes, 8%; P=.02). CONCLUSION: Among patients with glaucoma, patients with acquired pit of the optic nerve represent a subgroup who are at increased risk for progressive optic disk damage and visual field loss.     

Foveal dysfunction and central visual field loss in glaucoma

OBJECTIVE: To determine whether foveal function distal to the ganglion cell layer is an independent predictor of central visual field function in glaucoma. SETTING: University affiliated hospital and private practice. PARTICIPANTS: Twenty-seven eyes (27 patients) with normal-pressure glaucoma, 10 eyes (10 patients) with primary open-angle glaucoma, and 47 eyes of 47 matched normal volunteers. INTERVENTION AND MAIN OUTCOME MEASURES: Foveal cone electroretinogram (ERG) amplitude, relative optic cup to disc area and their relations to Humphrey full-threshold 30-2 visual field central 4-point mean total deviation (C4MTD) and pattern deviation (C4MPD). RESULTS: Foveal cone ERG amplitude was subnormal in 14 (37.8%) of the 37 glaucomatous eyes and lower in the glaucoma group compared with normal eyes (P<.01). The C4MTD and C4MPD were lower in glaucomatous eyes with subnormal amplitudes compared with those with normal amplitudes (P<.01 and P<.05, respectively). Amplitude was directly correlated with C4MTD (P<.01) and C4MPD (P<.01). Relative optic cup to disc area was inversely correlated with C4MTD (P<.001) and C4MPD (P<.001). Partial correlation analysis revealed that amplitude and relative optic cup to disc area were independent predictors of C4MTD and C4MPD. CONCLUSION: Foveal function distal to the ganglion cell layer and optic disc cupping independently predict central visual field function in glaucoma.     

HLA antigens and primary open-angle glaucoma in black Americans

Black patients with primary open-angle glaucoma, when compared to nonglaucomatous individuals, demonstrate significantly increased prevalences of the HLA antigens B7 and B12 and significantly decreased frequencies of A1 and A11. White patients with primary open-angle glaucoma have in common with blacks the increases in B7 and B12 and the decrease in A11, but present no deficit of A1. In addition, white patients with primary open-angle glaucoma demonstrate a significant increase of A3 and a decrease of Bw35, both of which are not found in blacks.     

Treatment and prognosis of secondary glaucoma in Fuchs' heterochromic iridocyclitis

After reviewing the records of 111 patients with Fuchs' heterochromic iridocyclitis, we studied the therapy and prognosis of secondary glaucoma in 30 of these 111 patients (27%) who had glaucoma or could be considered glaucoma suspects. Maximal medical therapy was unsuccessful in 22 of the 30 patients (73%). Surgical intervention (mostly trabeculectomies, half with 5-fluorouracil) successfully controlled intraocular pressure (< or = 21 mm Hg with or without medication) in 13 of the 18 operated-on patients (72%) after a mean follow-up of 26 months. All successfully operated-on patients retained a visual acuity of 20/80 or better. We had favorable results, possibly because of modern surgical techniques (use of 5-fluorouracil, sodium hyaluronate) or earlier surgical intervention, or both.     

Family history in primary open-angle glaucoma

A family history of glaucoma was found in 50% of patients with primary open-angle glaucoma (POAG) and 43% of patients with ocular hypertension (OH). Positive family history was twice as prevalent in those with OH and either HLA-B7 or B12 antigens than in OH with neither antigen (P less than .01). Although POAG occurred equally in men and women, the prevalence of a positive family history of glaucoma on the maternal side of the family in POAG patients was six to seven times greater than on the paternal side (P less than .0005). However, in patients with OH, but no glaucomatous field loss, there was no difference in prevalence of maternal and paternal family history. Even in OH with HLA-B7 or B12 antigens, there was no predominance of maternal family history. The implication that offspring were more likely to develop POAG when their mother's side of the family rather than their father's side had the disease has provided an additional potentially useful risk factor in patients with OH. In addition, it has raised interesting questions as to possible maternal cytoplasmic factors in the transmission and pathogenesis of POAG.