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We investigated the effects of the topical ocular hypotensives with or without half circumference argon laser trabeculoplasty (ALT) on intraocular pressure (IOP) of normal-tension glaucoma (NTG) eyes. Seventy-two NTG patients whose pretreatment mean IOP was > or = 15 mmHg at least in one eye were included and one randomly chosen eye from one patient were used for analysis. They were followed for at least 15 months after commencement of the therapy. The mean pretreatment IOP averaged 17.2 +/- 1.6 mmHg (mean +/- standard deviation, n = 72). All eyes were first treated with topical 2% carteolol. In eyes where IOP reduction was considered unsatisfactory, topical 1% pilocarpine or 0.04% dipivefrine was added. In eyes where IOP reduction was still unsatisfactory even with the two medications, half circumference ALT was performed. Mean IOP reduction was 1.5 mmHg in the eyes treated with topical medications alone and 2.5 mmHg in those treated by topical medications plus ALT. The mean outflow pressure reduction was 16 and 26%, respectively. In 40% of the all eyes, satisfactory IOP reduction was obtained by topical medications with or without additional ALT.

To discover if there is difference in central visual field damage between low-tension glaucoma (LTG) and primary open angle glaucoma (POAG) eyes, the data obtained with the 10-2 threshold program of the Humphrey visual field analyzer were analysed using logistic discriminant analysis. One hundred and four LTG eyes from 65 case (maximum IOP < or = 21 mmHg) and 48 POAG eyes from 34 cases (maximum IOP > or = 25 mmHg) with early to moderately advanced visual field damage were included. There was no significant difference in mean deviation (MD, STATPAC), refraction, or age between the 2 groups. The analysis demonstrated that an arcuate area in the upper central 5-10 degrees of the visual field was significantly more depressed in LTG than in POAG eyes.

A perimetric color vision test developed by Iijima et al. for evaluating parafoveal color vision provides information regarding local retinal function which can not be evaluated by other color vision tests. Using this method, we investigated para-foveal color sensitivity in normal-tension glaucoma (NTG) and primary open angle glaucoma (POAG) eyes whose glaucomatous visual field change determined with the central 30-2 program of the Humphrey visual field analyzer was confined to either the upper or the lower hemifield. The examined eyes had no abnormalities in ocular media with best corrected visual acuity of 1.0 or higher, and age, refraction, mean deviation, and extent of visual field loss were matched between NTG and POAG eyes. In the para-foveal area of the spared hemifield, acquired blue-yellow dyschromatopsia was detected in 52.3% of the POAG eyes and in 11.3% of the NTG eyes (p < 0.02, chi 2-test), and in damaged hemifield, it was found in 76.1% of the POAG eyes and 80.7% of the NTG eyes. We suggest that visual function is more diffusely damaged in POAG than in NTG and that the perimetric color vision test is useful for detecting glaucomatous damage which cannot be detected with conventional light threshold measurements.

We compared the results of visual field examination obtained with a Humphrey 30-2 program between 57 eyes of 57 low-tension glaucoma (LTG) and 57 eyes of 57 primary open-angle glaucoma (POAG; max IOP > or = 25 mmHg) cases, whose mean deviation (MD) given by STATPAC was > -10 dB. MD, age, and refraction showed no differences between the two groups. Corrected pattern standard deviation (CPSD) was significantly higher in the LTG group (p < 0.01). The total deviation (TD), deviation from the age-corrected normal reference, was found to be significantly lower by about 5 dB in the LTG group at two test points nasal-superior to the fixation point (Wilcoxon rank sum test, p < 0.01). Logistic discriminant analysis carried out to exclude a subtle difference in the distribution of the stage of disease between the two groups confirmed a significant between-group difference at the above-mentioned points. Furthermore, to compare the unevenness of visual field in the two groups, [TD-mean TD] was calculated, where mean TD was the average of 70 points of TD excluding the uppermost four points, and the same two points obtained above were found to decrease significantly in LTG, while all points were diffusely damaged in POAG. These results may imply a difference in the mechanism of visual field damage between LTG and POAG.

Postoperative courses of 68 eyes of 58 glaucoma patients who underwent posterior chamber intraocular lens implantation combined with trabeculectomy were studied retrospectively. The visual acuity was 0.5 or better in 66% of the eyes at 3 months postoperatively. The average intraocular pressure (IOP) was below 15 mmHg till 16 months postoperatively. An analysis of the postoperative course using the life-table method of Kaplan-Meier revealed that the probability of successful IOP control with medication was 83% at 18 months and 47% without medication. The subjects aged 75 years or older showed significantly higher success probability than those younger than 75 years, while types of glaucoma, the preoperative IOP control, location of conjunctival or sclerocorneal incision, postoperative 5-fluorouracil (5-FU) injections or surgical intervention on the iris had no significant effects on the probability of successful IOP control. The probability of subsistence of functional filtering bleb was 24% at 18-month follow-up, on which postoperative administration of 5-FU of 35 mg or more had a favorable effect.

In 288 eyes of 114 low-tension glaucoma (LTG) patients, the mean, peak, trough and magnitude of the diurnal fluctuation of the intraocular pressure (IOP) determined over a period of 24 hours (diurnal IOP) were correlated with the IOPs recorded at the daytime office (office IOP), refraction, extent of visual field loss, age, sex, blood pressure and obesity index by the method of multivariate analysis. Only the mean office IOP was found to have a statistically significant contribution for estimating the mean, peak and trough of the diurnal IOP with the proportion (R) of 0.71 0.67 and 0.68 respectively. Furthermore, an analysis of the IOP data obtained from 118 LTG suspects using the receiver operating characteristics (ROC) curve showed that a patient whose peak diurnal IOP exceeds 21 mmHg could be detected with a sensitivity of 100% and a specificity of 46% if around-the-clock IOP measurements were carried out in patients whose mean office IOP are above 16 mmHg at least in one eye. In view of high prevalence of LTG in Japanese, estimation of mean diurnal IOP from mean office IOP and exclusion of primary open angle glaucoma using the mean office IOP of 16 mmHg as a cutoff IOP level are thought to be clinically useful.

Around-the clock intraocular pressure (IOP) measurement were performed in 104 eyes of 52 low tension glaucoma (LTG) cases. Subjects were all hospitalized and IOP measurements were done every 2 hours from 6:00 AM to 12:00 PM and every 3 hours from 12:00 PM to 6:00 AM. All LTG patients met the following criteria, (1) glaucomatous optic nerve head change and corresponding visual field defect, (2) normal open angle, (3) IOP less than or equal to 21mmHg at any time of IOP measurement, (4) no obvious neurological or rhinological disorders that could affect the optic nerve, (5) no history of hemodynamic crisis or cardiovascular disorders except mild hypertension. Peak IOPs were most frequently observed at 10:00 AM, but about 55% of all observed peaks were in the time period from 6:00 PM to 8:00 AM. Most troughs were observed from 2:00 PM to 10:00 PM. The mean IOP, the diurnal variation and the difference between both eyes in the same person averaged 14.1, 4.9, and 0.6mmHg, respectively. Assuming that the period of rhythm is 24 hours, the results of IOP measurements fitted a cosine curve using the least square method. In 44% of all eyes, significant correlation coefficient (r greater than or equal to 0.6, p less than 0.05) between the measured and the predicted IOPs was noted, and an equation, IOP = 14.3 + 1.7cos 2 pi (t/24-0.4 radian), was obtained. Comparing the present results with former ones, we concluded that the IOP changes in LTG patients were similar to those in normal individuals.

To study the effect of the intraocular pressure (IOP) on the visual field (VF) damage in low tension glaucoma (LTG), we compared the IOP and the VF damage in both eyes of 46 LTG patients. As an index of the VF damage, we used the mean deviation (MD) value calculated by the Humphry (30-2) STATPAC program, and for the IOP data, the mean of 24 hour IOP measurements (diurnal IOP) and the mean of the IOPs measured at each visit to our outpatient clinics (follow-up IOP). In 13 cases, the diurnal and the follow-up IOPs were 0.3 mmHg higher or more in the more damaged eye than those in the less damaged eye, and in 7 cases they were 0.3 mmHg higher or more in the less damaged eye than those in the more damaged eye. Between these two groups, no significant difference was seen in the value of MD, but the diurnal IOP and the follow-up IOP was significantly higher in the former than in the latter group. By discrimination analysis, the two groups were distinguished at the diurnal IOP of 14.1 mmHg (hit rate 77.6%) and the follow-up IOP of 15.0 mmHg (74.2%). An analysis using the whole 46 LTG cases yielded the following results: when the diurnal or follow-up IOP of the more damaged eye was higher than the above determined level, the IOP in the more damaged eye was significantly higher than that in the contralateral less damaged eye.(ABSTRACT TRUNCATED AT 250 WORDS)