Diurnal intraocular pressure in juvenile open-angle glaucoma

Outpatient diurnal intraocular pressures were obtained on 10 patients with juvenile open-angle glaucoma at approximately 6 hour intervals. There were 8 males and 2 females with an age range of 19 to 38 years. All glaucomatous medications were stopped 24 hours before recording the tensions. The peak intraocular pressure was recorded at the 6 PM interval in 6 of the 10 patients. Three patients recorded their highest pressures at the 12 AM (midnight) interval. Extraordinarily wide angles were observed in all cases and myopia was a common refractive error. Although the family history was not known in 3 patients, there was a positive family history of glaucoma in 7 of the 10 patients, which suggests an autosomal dominant mode of inheritance.     

Diurnal variation of intraocular pressure in primary open-angle glaucoma.

Intraocular pressure was measured with a Goldmann applanation tonometer in 12 normal individuals (24 eyes), 14 ocular hypertensives (28 eyes), and 14 patients (27 eyes) with primary open-angle glaucoma every hour for 24 hours. In most subjects, pressure was highest sometime during the day and pressure elevation before rising was not demonstrated. The lowest intraocular pressure was most frequently observed early in the morning, whether the patient was normotensive or hypertensive. Fourteen of 27 glaucomatous eyes had intraocular pressure below 20 mm Hg early in the morning.     

Diurnal intraocular pressure fluctuation and its risk factors in angle-closure and open-angle glaucoma

Purpose

To evaluate intraocular pressure (IOP) fluctuation during office hours and its predictive factors in untreated primary angle-closure suspects (PACS); post-iridotomy primary angle closure (PAC) and primary angle-closure glaucoma (PACG) eyes with or without IOP-lowering medication(s) as appropriate and medically treated primary open-angle glaucoma (POAG) eyes.

Methods

One-hundred seventeen eyes (29 PACS, 30 PAC, 28 PACG, and 30 POAG) of 117 patients were included in this cross-sectional study. The subjects underwent hourly IOP measurements with Goldmann tonometer from 0800 to 1700 hours. Subjects with PAC and PACG had laser peripheral iridotomy at least 2 weeks prior to the inclusion. SD of office-hour IOP readings was the main outcome measure.

Results

IOP fluctuation differed between the groups (P=0.01; Kruskal–Wallis Test). Post hoc Mann–Whitney U-tests showed significantly less IOP fluctuation in PACS compared with PACG (P<0.01). Peak office-hour IOP was observed in the morning in untreated subjects and in the early afternoon in treated subjects. A stepwise linear regression model identified the presence of peripheral anterior synechiae (PAS), thickness of lens, large vertical cup-to-disc ratio (VCDR), and PAC category as significant predictive factors associated with office-hour IOP fluctuation.

Conclusions

Diurnal IOP fluctuation in asymptomatic PACSs was less than that in treated PACG subjects and was at least comparable to that in treated PAC and POAG subjects. The greater the amount of PAS, the thicker the lens, the larger the VCDR, the greater was the IOP fluctuation during office hours.     

青光眼昼夜眼压波动

病理性高眼压和较大的昼夜眼压波动是青光眼视神经损害进展的重要危险因素.眼压具有波动性,正常人眼压波动的峰值多出现于凌晨,这种波动与体位、眼灌注压、眼轴等有关.正常眼压性青光眼患者眼压波动是视野进展的重要危险因素,且经24小时眼压监测发现大部分眼压是存在异常的,因此需根据其昼夜眼压曲线明确诊断和针对性治疗;原发性开角型青光眼患者昼夜眼压波动规律与正常人相似,眼压高峰多在夜间,但波动范围可能比正常人大,且双眼的波动呈明显的一致性;激光周边虹膜切开术后的慢性闭角型青光眼患者的昼夜眼压波动较大,其眼压波动与基线眼压和房角粘连程度呈正相关.与激光和药物相比,小梁切除术更有利于控制长期和昼夜的眼压波动.抗青光眼药物中前列腺素类药物是控制昼夜眼压波动效果最好的滴眼剂.     

Trimolol: effect on intraocular pressure in chronic open-angle glaucoma.

Timolol maleate is an effective agent of reducing intraocular pressure in patients with chronic open-angle glaucoma. To date, there are no adverse side effects demonstrable with use of this medication. Its mechanism of action is not clearly delineated but preliminary data suggest an effect on outflow facility.     

Postural response of intraocular pressure in chronic open-angle glaucoma following trabeculectomy.

Forty-six eyes with chronic open-angle glaucoma (COAG) and 24 eyes which had previously undergone trabeculectomy for COAG were studied and the postural response of the intraocular pressure compared with that of 70 normal eyes. In all three groups the greatest rise in intraocular pressure (IOP) occurred when the subject changed from the sitting to the lying position. In the control group this was never more than 2 mmHg in any subject. The rise was greater than 2 mmHg in 93% of the patients suffering from COAG who were treated medically and in 100% of the eyes of those on which trabeculectomy had been performed. The well recognised abnormal postural response of intraocular pressure in COAG appears both to be retained and to be unaffected in those eyes which have undergone trabeculectomy.     

Mean intraocular pressure and progression based on corneal thickness in primary open-angle glaucoma.

PURPOSE: The aim of this study was to evaluate the association of corneal thickness on the incidence of glaucomatous progression at individual levels of intraocular pressure. METHODS: A retrospective, noninterventional evaluation of patients with primary open-angle glaucoma who were either stable over 5 years or had glaucomatous progression before 5 years of follow-up was performed. Each patient had central thickness corneal measurements documented. RESULTS: We included 310 patients in this study. Patients with thicker (at least 0.571 mm, n = 77) and mid-range corneas (0.511-0.570 mm, n = 177) progressed in 14% (n = 11) and 18% (n = 31) of cases, respectively. The progression rate for patients with a mean pressure of less than 17 mmHg in both groups was 12%-13%. In contrast, the progression rate in patients with 18 mmHg or higher was 23% and 16% in the mid-range and thick corneal groups, respectively. In patients with thinner corneas (equal to or less than 0.510 mm, n = 56), the progression rate was 32% (n = 18). The progression rate was 60% (12 of 20) with mean pressures of at least 18 mmHg or higher, but 18% with mean pressures equal to or less than 17 mmHg. Univariant (P = 0.05), but not multivariant, analysis showed that corneal thickness was a risk factor for progression. CONCLUSIONS: This study suggests that the reduction of intraocular pressure helps to prevent progression in patients with primary open-angle glaucoma. However, for patients with thinner corneas, pressure reduction may potentially be of even greater importance to help avoid glaucomatous progression. Future study should clarify potential variables associated with thin corneas and glaucomatous progression.     

Long-term progression at individual mean intraocular pressure levels in primary open-angle and exfoliative glaucoma

PURPOSE: To describe progression and non-progression rates at individual mean intraocular pressure (IOP) levels for patients with primary open-angle and exfoliative glaucoma. METHODS: A meta-analysis of five previously published retrospective studies describing progression and non-progression rates at individual intraocular pressure levels over 5 or more years of follow-up. All patients had primary open-angle (four studies) or exfoliative glaucoma (one study). RESULTS: This meta-analysis included 822 patients of whom 655 (80%) had primary openangle glaucoma and 167 (20%) had exfoliative glaucoma. In total, 220 patients progressed (27%), while 602 (73%) remained stable over 5 years. The mean IOP was 20.0 for progressed and 17.1 mmHg for stable patients (p=0.0004). The peak IOP was 29.1 for progressed and 23.6 mmHg for stable patients (p=0.0014). At an IOP level >18 mmHg, 49% of patients remained stable; at 18 mmHg, 78%; between 13 and 17 mmHg, 82%; and <13 mmHg, 96%.Additional factors associated with progression were older age (p=0.0004) and exfoliative glaucoma (p=0.0001). However, multivariant regression analysis identified only mean IOP as a risk factor for progression (p=0.039). CONCLUSIONS: This study suggests that maintaining an IOP well within the normal range over 5 years in patients with primary open-angle or exfoliative glaucoma helps to prevent glaucomatousprogression.     

Impact of intraocular pressure after filtration surgery on visual field progression in primary open-angle glaucoma

PURPOSE: To compare visual field progression after trabeculectomy in eyes showing a postoperative intraocular pressure (IOP) less than or equal to 16 mmHg and eyes with an IOP of 17 to 21 mmHg. METHODS: A retrospective cohort study design was used. A total of 101 eyes of 101 consecutive patients undergoing trabeculectomy for primary open-angle glaucoma (POAG) with a postoperative IOP less than or equal to 21 mmHg were divided into two groups: Group 1 included eyes showing a postoperative IOP less than or equal to 16 mmHg at all visits and Group 2 included eyes with a postoperative IOP between 17 and 21 mmHg. In turn, each of these groups was divided into two subgroups according to whether treatment was required for IOP control. Glaucomatous visual field control during follow-up was compared between the subject groups. RESULTS: Kaplan-Meier analysis revealed glaucomatous visual field control in 98.53% of the eyes in Group 1 and 89.06% of those in Group 2 at 5 years, the difference between the groups being significant. CONCLUSIONS: Glaucomatous disease progression is less frequent when IOP is less than or equal to 16 mmHg in all the follow-up visits after trabeculectomy. The results indicate a definite benefit of low IOP in visual field control.     

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 +/- 2.0 mmHg(mean +/- standard deviation), 12.8 +/- 1.7 mmHg, and 4.0 +/- 1.3 mmHg, 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 be come commercially available soon, so that we can provide them with more individualized glaucoma treatment using the appropriate combination of medicines.     

Target intraocular pressure and risk factors for progression of visual field loss in primary open-angle glaucoma

PURPOSE: Evaluation of intraocular pressure(IOP) control below the target level stated by Iwata and study of risk factors for progression of visual field loss in primary open-angle glaucoma (POAG) despite successful reduction of IOP. SUBJECTS AND METHODS: Statistical difference of visual field deterioration between 27 eyes of POAG with IOPs above target levels and 48 eyes of POAG with IOP below target levels was examined for 28.1 +/- 10.2(mean +/- standard deviation) months. The relationship between the progression of visual field loss and factors of initial visual field loss, mean IOP, variance of IOP, peripapillary atrophy (zone beta), records of glaucoma surgery, age, and sex were studied in 48 patients(48 eyes) with IOPs below target levels. RESULTS: Eight of the 48 eyes(16.7%) showed progression of visual field loss with IOPs below their target levels whereas 15 of the 27 eyes(55.6%) had IOPs above their target levels(p = 0.002). The risk factors for the progression of visual field loss in POAG despite good control of IOP were severity of initial visual field loss(p = 0.003), peripapillary atrophy(p = 0.002), and male sex(p = 0.03). CONCLUSIONS: The control of IOP below target level is beneficial for patients with POAG. However, the risk factors which represent circulatory damage, such as peripapillary atrophy, may have a bad influence on the continuing deterioration of visual fields in patients with severe visual field damage, independently of good control of IOP.     

Relationships among systemic blood pressure, intraocular pressure, and open-angle glaucoma

Several vascular factors, including systemic hypertension (or high blood pressure [HBP]), ocular perfusion pressure, and nocturnal hypotension, have been identified as risk factors for the development and progression of glaucoma. The results of epidemiologic studies of these factors and their relationships to intraocular pressure (IOP) and open-angle glaucoma (OAG) have been contradictory. Inconsistent definitions of HBP and OAG, inconsistent design, and differing population characteristics within these studies have obfuscated definitive conclusions. Here, we review the relationships among blood pressure, IOP, and OAG.     

Diurnal variation of intraocular pressure in low tension glaucoma

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.     

Posture-induced changes in intraocular pressure: comparison of pseudoexfoliation glaucoma and primary open-angle glaucoma

Purpose

The objective of this study was to evaluate and compare the IOP values in the sitting and supine positions in primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG) patients. We also investigated possible relationships between the level of visual field damage and postural IOP change.

Methods

Twenty-nine patients with POAG and 32 patients with PXG were recruited to the study. An Icare PRO tonometer was used to measure IOP in the sitting and supine positions. Intraocular pressure in the sitting position was also measured with a Goldmann applanation tonometer (GAT). Humphrey field analyzer 750 data taken within the previous 3 months were obtained and analyzed.

Results

The mean difference between the GAT and the Icare PRO tonometer readings was 0.12 ± 0.8 mmHg, and the tonometers were in close agreement (r = 0.964; P < 0.0001). The mean Icare PRO IOP in the sitting position was 16.6 ± 3.3 mmHg in the POAG group and 14.9 ± 2.7 mmHg in the PXG group. The average rise was 1.7 ± 1.2 mmHg in the POAG group and 2.9 ± 1.9 mmHg in the PXG group. The difference in IOP between the sitting and supine positions was significant between the groups (P = 0.001). The ?IOP was negatively correlated with both the mean deviation and the visual field index (P < 0.0001 for both). The ?IOP and pattern standard deviation were positively correlated (P < 0.0001).

Conclusions

A higher increase in IOP was observed in PXG patients from the sitting to the supine position than in POAG patients. Postural variation in IOP was found to be associated with the severity of visual field damage.