Diurnal Variation of Intraocular Pressure in Normal-tension Glaucoma

Purpose Measurement of diurnal variation of intraocular pressure (IOP) is important for precise diagnosis of normal-tension glaucoma (NTG). We studied diurnal variation of IOP of NTG using a self-measuring tonometer.Methods A total of 159 patients (318 eyes) who were diagnosed as having NTG in Osaka Koseinenkin Hospital between 1994 and 2002 measured their own diurnal variation of IOP at home every 3 hours (8 times a day) using a prototype self-measuring non-contact air-puff tonometer (Hometonometer).Results The maximum IOP, the minimum IOP, and the range of diurnal variation of IOP were 16.8 ± 2.0mmHg (mean ± standard deviation), 12.8 ± 1.7mmHg, and 4.0 ± 1.3mmHg, respectively. Maximum IOP occurred most frequently at noon (24.3%), 9:00 am (21.4%), and 6:00 am (17.4%). In 69.2% of eyes, maximum IOP was found during outpatient clinic hours (9:00 am to 6:00 pm). Minimum IOP occurred most frequently at midnight (34.1%), 3:00 am (22.8%), and 9:00 pm (17.8%).Conclusions Approximately 30% of NTG patients have maximum IOP outside of outpatient clinic hours, and therefore measuring IOP in the early morning is important for determining the precise diurnal variation of their IOP. We hope that a safe self-measuring tonometer with which patients can measure their own IOP will become commercially available soon, so that we can provide them with more individualized glaucoma treatment using the appropriate combination of medicines. Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc 107:375–379, 2003)     

Glaucoma Visual Field Analysis by Computed Profile of Nerve Fiber Function in Optic Disc Sectors

Automated perimetry has decreased the subjective aspects of data collection, but analysis has remained largely subjective. A microcomputer permits more objective analysis by regrouping and averaging data points in the threshold static visual field according to their retinotopic projection onto the optic disc rather than according to their eccentricity from the point of fixation. The applications of the technique include (1) following glaucomatous visual field loss, (2) differentiating glaucomatous from other forms of visual loss, and (3) studying the effects of aging on the visual field. Six formulas for data analysis are described, and their relative usefulness discussed. Percent loss or gain seemed to convey the most diagnostic information to the clinician. Percent of expected sensitivity was less than the decimal visual acuity when the diagnosis was glaucoma but greater when the diagnosis was cataract. In some cases this analytic method should provide information that could favorably affect patient management.     

Visual Field Damage in Normal-tension Glaucoma Patients With or Without Ischemic Changes in Cerebral Magnetic Resonance Imaging

Purpose To compare the pattern of visual field damage between normal-tension glaucoma (NTG) patients with signs indicative of ischemic changes and those NTG patients without signs of ischemic changes, using brain magnetic resonance imaging (MRI), in a single center, cross-sectional study.Methods In 94 consecutive NTG patients who were younger than 61 years old, brain MRI images were obtained using fluid-attenuated inversion recovery pulse sequences. The presence of signs indicative of ischemic changes in brain MRI images was decided separately by two neuroradiologists masked to the diagnosis and stage of glaucoma. Visual field testing was performed using the 30-2 program of the Humphrey Visual Field Analyzer. Between the patients with signs indicative of ischemic changes in brain MRI (ischemic group) and those without MRI signs (nonischemic group), total deviation (TD) at each test point less the average of TDs of the 30-2 program ([TD – TD_mean])—was compared at each test point.Results Signs indicative of ischemic changes in brain MRI were found in 32 of the 94 patients (34.0%). Age, blood pressure, refraction, intraocular pressure, the average of TDs, mean deviation, and corrected pattern standard deviation were not significantly different between the ischemic (N = 32) and nonischemic (N = 62) groups (P > 0.2). [TD – TD_mean] in the ischemic group was significantly smaller than that in the nonischemic group at 6 nonedge contiguous test points in the inferior pericentral to nasal field (P = 0.005–0.047).Conclusion NTG patients with signs indicative of ischemic changes in brain MRI had a relatively deeper depression in the inferior pericentral visual field. Jpn J Ophthalmol 2004;48:340–344 © Japanese Ophthalmological Society 2004     

Comparison of the Thickness of the Lamina Cribrosa and Vascular Factors in Early Normal-tension Glaucoma with Low and High Intraocular Pressures

Purpose

To compare the thickness of the lamina cribrosa (LC) and vascular factors of early normal-tension glaucoma (NTG) patients with high and low intraocular pressure (IOP) that are expected to be associated with the development of glaucoma.

Methods

Seventy-one Korean NTG patients with low IOP (the highest IOP <15 mmHg, 40 patients) and high IOP (the lowest IOP >15 mmHg, 31 patients) were included in this study. The thickness of LC and vascular factors were compared. The thickness of the LC was measured using the enhanced depth imaging method with spectral domain optical coherence tomography (Heidelberg Spectralis).

Results

The mean thickness of the central LC was 190.0 ± 19.2 µm in the low IOP group and 197.8 ± 23.6 µm in the high IOP group, but there was no statistical significant difference between the two groups (p > 0.05). The prevalence of self-reported Raynaud phenomenon was significantly higher in the low IOP group (33.0%) than the high IOP group (10.3%, p = 0.04).

Conclusions

The laminar thickness did not significantly differ between the high and low IOP groups. However, the prevalence of Raynaud phenomenon was higher in the low IOP groups. These results suggest that the development of glaucoma with low IOP patients may be more influenced by peripheral vasospasm, such as Raynaud phenomenon, rather than laminar thickness in NTG.     

Characteristics of Reversal Optic Cupping in Adults Glaucoma after Reduction of Intraocular Pressure

Purpose:According to Quigley‘s hypothesis the dense of connective tissue is the least and the pores of the lamina cribrosa are the largest at the superior and infe-rior poles of the lamina cribrosa,therefore they are the most vulnerable location to be involved in the characteristic glaucomatous optic nerve damage,To get clin-ical evidence for the hypltheses,the reversal of optic cup in adults glaucoma after reduction of intraocular pressure(IOP)was examined.Methods:The stereoscopic flicker comparison on with computerized image sys-tem was used to monitor the optic cup‘s changing,2 serial superposed stereo pairs were displayed alternatively and rapidly and the changing parts appeared moving Under the stereoscopic observation ,hthe changes of 3-dimention optic cup could be seen and the false positive phenomena caused by photographic angle variation,vascular pulsation could be differentiated from the characteristic change of the cup.Stereo fundus photographs were taken from 31eyes with hy-pertension glaucoma before and after treatment of reduction of IOPs which was either diamox administration or trabeculectomy.Results:the result showed that the reversal of optic cups after reduction of IOPs were mostly asymmetrical,especially at the inferior and/or superior poles.By multiple stepwise regression.it is known that the amount of the change is only correlated with the initial elevated IOP.Conclusions:The study indicated that it was the distortion and deformity of the lamina cribrosa leading to shearing stress that results in glaucomatous character-istic damage in structure and function.The individul tolerance of the lamina cribrosa to the high intraocular pressure and the locations of indivdual vulnerable at he optic nerve head are various.Eye Science1995;11:155-160.     

Circadian Blood Pressure and Intraocular Pressure Patterns in Normal Tension Glaucoma Patients with Undisturbed Sleep

Purpose

To investigate and compare the circadian pattern of blood pressure (BP), intraocular pressure (IOP) and mean ocular perfusion pressure (MOPP) while experiencing undisturbed sleep in normal-tension glaucoma (NTG) and non-glaucoma control patient groups.

Methods

Twenty-four eyes from 24 patients diagnosed with NTG and 22 eyes from 22 control group patients were enrolled. Systolic BP, diastolic BP and IOP were measured every two hours except for the period of time from 1 AM to 7 AM in the NTG group and from 11 PM to 7 AM in the control group over a one-day period. IOP and hemodynamic parameters were then compared between the two groups. NTG patients were subdivided according to the degree of morning BP dip and IOP, and hemodynamic parameters and visual field indices (mean deviation and pattern standard deviation) were also compared among these subgroups.

Results

There were no significant differences in mean systolic BP, mean diastolic BP and mean arterial pressure (MAP) between the NTG and the control groups. The NTG group showed a significantly large morning BP dip compared to the control group (7.1±4.2% vs. 3.8±3.4%, p=0.022). However, there were no significant differences in mean or fluctuation of MOPP between the two groups. Morning over-dippers showed significantly large MAP and MOPP fluctuations compared to non-dippers and dippers, while there were no significant differences in visual field indices among the three subgroups.

Conclusions

NTG patients showed significant morning BP dips compared to the control group. The marked morning BP dip was associated with significantly large MAP or MOPP fluctuations but was not associated with visual field indices.     

Association between Nocturnal Blood Pressure Reduction and Progression of Visual Field Defect in Patients with Primary Open-Angle Glaucoma or Normal-Tension Glaucoma

Purpose To assess prospectively the relationship between nocturnal blood pressure reduction (dip) and progression of the visual field defect in patients with normal-tension glaucoma (NTG) or primary open-angle glaucoma (POAG).Patients and Methods The subjects studied were 38 patients with glaucoma (23 patients with NTG, 15 patients with POAG), in whom 48-h ambulatory blood pressure monitoring was conducted, who were followed for at least 4 years, and in whom reliable visual field tests were performed at least 5 times. The progression was determined by the mean deviation (MD) slope analysis system installed in the Humphrey field analyzer Statpac program. Glaucoma patients with a dip of <10% were assigned to the nondipper group, those with a dip of 10%–20% to the tipper group, and those with a dip of >20% to the extreme dipper group. The dipper group was defined as physiologic dippers, while the nondipper and the extreme dipper groups were defined as nonphysiologic dippers, to study the relationship between the disturbance of the dip and progression of the visual field defect.Results Thirteen patients showed significant progression, while 25 patients did not. There were no significant differences in the mean intraocular pressure and follow-up period between the patients with progression and those without progression. Half (7/14) of the nondippers, 20% (4/20) of the dippers, and 50% (2/4) of the extreme dippers showed progression, indicating a tendency of progression in the nondipper and the extreme dipper groups. The nonphysiologic dippers had a higher incidence of progression compared with the physiologic dippers (P = 0.05). Among the glaucoma patients in the nondipper and dipper categories only, those with progression had significantly smaller dips (P = 0.02).Conclusion These results suggest that disturbance in the physiologic dip may be involved in the progression of glaucoma. Jpn J Ophthalmol 2004;48:380–385 © Japanese Ophthalmological Society 2004