Untreated 24-h intraocular pressures measured with Goldmann applanation tonometry vs nighttime supine pressures with Perkins applanation tonometry

Dorzolamide/Timolol Fixed Combination: Learning from the Past and Looking Toward the Future

The key clinical attributes of preserved dorzolamide/timolol fixed combination (DTFC) and the emerging potential of preservative-free (PF) DTFC are reviewed with published evidence and clinical experience. The indications and role of DTFC in current glaucoma management are critically discussed. Preserved DTFC became the first intraocular pressure (IOP)-lowering fixed combination (FC) approved by the US Food and Drug Administration (FDA) and remains one of most commonly used medications worldwide. The pharmacological properties of DTFC reflect those of its two time-tested constituents, i.e., the carbonic anhydrase inhibitor dorzolamide and the non-selective beta-blocker timolol. In regulatory studies DTFC lowers IOP on average by 9 mmHg (32.7%) at peak and by 7.7 mmHg (27%) at trough. In trials DTFC shows equivalence to unfixed concomitant therapy, but in real-life practice it may prove superior owing to enhanced convenience, elimination of the washout effect from the second drop, improved tolerability, and better adherence. PF DTFC became the first PF FC approved, first in unit-dose pipettes, and more recently in a multidose format. Cumulative evidence has confirmed that PF DTFC is at least equivalent in efficacy to preserved DTFC and provides a tangible clinical benefit to patients with glaucoma suffering from ocular surface disease by improving tolerability and adherence. Finally, we identify areas that warrant further investigation with preserved and PF DTFC

Evaluation and treatment of glaucoma 24hours a day. Where are we and where are we going?

Current management of glaucoma generally involves medical, laser, or surgical treatment in order to achieve an intraocular pressure (IOP) control which is commensurate with either stability or delayed progression of the disease. Although the follow-up of glaucoma patients is usually carried out with sporadic and isolated intraocular pressure measurements, the literature already indicates that this might not the best option to manage glaucoma patients. This article reviews the importance of 24hours intraocular pressure monitoring based on studies and publications that exist in this regard to date. A critical review on the methodology of these publications has been conducted. The need is stressed for further studies on the intraocular pressure patterns in different types of glaucoma, as well as the pattern with different therapies used in glaucoma aimed at optimising the management of the disease.

Diurnal and 24-h Intraocular Pressures in Glaucoma: Monitoring Strategies and Impact on Prognosis and Treatment

The present review casts a critical eye on intraocular pressure (IOP) monitoring and its value in current and future glaucoma care. Crucially, IOP is not fixed, but varies considerably during the 24-h cycle and between one visit and another. Consequently, a single IOP measurement during so-called office hours is insufficient to characterize the real IOP pathology of a patient with glaucoma. To date IOP remains the principal and only modifiable risk factor for the development and progression of glaucoma. Only by evaluating IOP characteristics (mean, peak and fluctuation of IOP) at diagnosis and after IOP-lowering interventions can we appreciate the true efficacy of therapy. Unfortunately, a major limiting factor in glaucoma management is lack of robust IOP data collection. Treatment decisions, advancement of therapy and even surgery are often reached on the basis of limited IOP evidence. Clearly, there is much room to enhance our decision-making and to develop new algorithms for everyday practice. The precise way in which daytime IOP readings can be used as predictors of night-time or 24-h IOP characteristics remains to be determined. In practice it is important to identify those at-risk glaucoma patients for whom a complete 24-h curve is necessary and to distinguish them from those for whom a daytime curve consisting of three IOP measurements (at 10:00, 14:00 and 18:00) would suffice. By employing a staged approach in determining the amount of IOP evidence needed and the rigour required for our monitoring approach for the individual patient, our decisions will be based on more comprehensive data, while at the same time this will optimize use of resources. The patient’s clinical picture should be the main factor that determines which method of IOP monitoring is most appropriate. A diurnal or ideally a 24-h IOP curve will positively impact the management of glaucoma patients who show functional/anatomical progression, despite an apparently acceptable IOP in the clinic. The potential impact of nocturnal IOP elevation remains poorly investigated. The ideal solution in the future is the development of non-invasive methods for obtaining continuous, Goldmann equivalent IOP data on all patients prior to key treatment decisions. Moreover, an important area of future research is to establish the precise relationship between 24-h IOP characteristics and glaucoma progression.

Short-term reproducibility of intraocular pressure and ocular perfusion pressure measurements in Chinese volunteers and glaucoma patients

Background

To evaluate the short-term reproducibility of diurnal intraocular pressure (IOP) and ocular perfusion pressure (OPP) measurements in normal volunteers, untreated normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG) patients.

Methods

Fifty-four healthy volunteers (control group), 67 NTG patients and 54 POAG patients were recruited. The IOPs of both eyes were measured with a Goldmann applanation tonometer at 3-h intervals over 2 consecutive days. Blood pressure (BP) measurements were collected at the same times. The mean IOP/OPP, peak IOP/OPP, trough IOP/OPP and IOP/OPP fluctuations on each day were also calculated. The intraclass correlation coefficients (ICCs) were used to evaluate the reproducibilities.

Results

In the control group, the ICCs of mean IOP, peak IOP, trough IOP and IOP fluctuation were 0.921, 0.889, 0.888, and 0.661, respectively, and the ICCs of the mean OPP, peak OPP, trough OPP and OPP fluctuations were 0.962, 0.918, 0.953, and 0.680, respectively. In the NTG group, the ICCs of the mean IOP, peak IOP, trough IOP and IOP fluctuation were 0.862, 0.741, 0.798, and 0.290, respectively, and the ICCs of the mean OPP, peak OPP, trough OPP and OPP fluctuations were 0.947, 0.828, 0.927, and −0.008, respectively. In the POAG group, the ICCs of the mean IOP, peak IOP, trough IOP and IOP fluctuation were 0.857, 0.666, 0.808, and 0.546, respectively, and the ICCs of the mean OPP, peak OPP, trough OPP and OPP fluctuation were 0.934, 0.842, 0.910, and 0.093, respectively.

Conclusion

The IOP measurements within a single day were not highly reproducible in the short-term. The normal volunteers exhibited better IOP and OPP reproducibilities than the glaucoma patients. The IOP and OPP fluctuations could not be accurately evaluated based on the IOP or OPP measurements within a single day.

Twenty-four-hour intraocular pressure and ocular perfusion pressure characteristics in newly diagnosed patients with normal tension glaucoma

PurposeTo determine the mean 24-h intraocular pressure (IOP) and mean ocular perfusion pressure (MOPP) characteristics of newly diagnosed, previously untreated, Caucasian, normal tension glaucoma (NTG) patients and to identify relationships between these features and visual field (VF) loss at diagnosis.MethodsConsecutive newly diagnosed NTG patients underwent 24-h habitual IOP and blood pressure (BP) monitoring. Parameters from pooled measurements obtained in the sitting (0800-2200 hours) and supine (1200-0600 hours) positions were compared and associations were sought with VF mean deviation (MD) and pattern standard deviation (PSD).ResultsSixty-two Caucasian NTG patients (24 men and 38 women) successfully completed circadian IOP and BP monitoring. In habitual position, 8 subjects (12.9%) exhibited a diurnal acrophase, 42 subjects (67.7%) demonstrated a nocturnal acrophase, one subject (1.6%) showed a flat rhythm and 11 patients (17.7%) revealed a biphasic/polyphasic rhythm. Nighttime MOPP values (supine position) were significantly greater than diurnal values (sitting position); (P<0.001). No association could be demonstrated between glaucomatous damage, as indicated by VF parameters, and either mean habitual 24-h IOP (P=0.20 and P=0.12 for MD and PSD, respectively), or habitual 24-h MOPP (P=0.96 and 0.29, for MD and PSD, respectively).ConclusionsIn this cohort of Caucasian NTG patients, most patients exhibited a nocturnal IOP acrophase when evaluated in a habitual position. No association was found between 24-h IOP or MOPP and VF damage.

24-h Efficacy of Glaucoma Treatment Options

Current management of glaucoma entails the medical, laser, or surgical reduction of intraocular pressure (IOP) to a predetermined level of target IOP, which is commensurate with either stability or delayed progression of visual loss. In the published literature, the hypothesis is often made that IOP control implies a single IOP measurement over time. Although the follow-up of glaucoma patients with single IOP measurements is quick and convenient, such measurements often do not adequately reflect the untreated IOP characteristics, or indeed the quality of treated IOP control during the 24-h cycle. Since glaucoma is a 24-h disease and the damaging effect of elevated IOP is continuous, it is logical that we should aim to understand the efficacy of all treatment options throughout the 24-h period. This article first reviews the concept and value of diurnal and 24-h IOP monitoring. It then critically evaluates selected available evidence on the 24-h efficacy of medical, laser and surgical therapy options. During the past decade several controlled trials have significantly enhanced our understanding on the 24-h efficacy of all glaucoma therapy options. Nevertheless, more long-term evidence is needed to better evaluate the 24-h efficacy of glaucoma therapy and the precise impact of IOP characteristics on glaucomatous progression and visual prognosis.

Postural and diurnal fluctuations in intraocular pressure across the spectrum of glaucoma

AIMS

To evaluate postural fluctuations (PFs) and diurnal variation (DV) of intraocular pressure (IOP) in patients with untreated glaucoma, glaucoma suspects and healthy volunteers, and study their relationship, if any, to the extent of glaucomatous damage.

METHODS

This prospective, observational cross-sectional study was carried out in a tertiary care referral institution. The patient population included five groups of patients comprising the following: 19 with ocular hypertension (OHT), 26 with optic discs suspicious for glaucoma (DS), 18 with normal tension glaucoma (NTG), 19 with primary open angle glaucoma (POAG) and 20 normal subjects. The IOP was measured at four time periods using Perkins tonometer, in sitting and supine positions. The main outcome measures were change in IOP with posture, the DV in both postures and the relationship between PF, DV and the extent of visual field damage.

RESULTS

The supine IOP was significantly higher than the sitting IOP, at all time points of the day, in all groups (p<0.001). The PF at 04:30 was significantly higher in POAG, OHT and NTG. The PF at 09:00 correlated significantly with the mean deviation (MD) on visual fields in the NTG group (r=0.735; p=0.001). The DV did not correlate with the MD in any of the five groups studied.

CONCLUSIONS

The significantly higher supine IOP is frequently missed in routine glaucoma practice. An early morning supine IOP measurement may reveal a peak IOP hitherto not picked up during routine office IOP measurements, and may be a useful measurement in unexplained progressive glaucoma.

Twenty-four-hour intraocular pressure monitoring in normotensive patients undergoing chronic hemodialysis

PURPOSE

To investigate 24-hour intraocular pressure (IOP) changes caused by hemodialysis (HD).

METHODS

A prospective, observational, comparative 24-hour trial was performed on consecutive subjects with normal IOP undergoing maintenance HD 3 days a week between 13:00 and 17:00 hours in an academic setting. Following a comprehensive ocular assessment, those with conditions that may influence IOP were excluded and one eye was randomly selected. Twenty-four-hour IOP monitoring was performed on HD day 1 and then on a day without HD. The IOP was measured at 10:00, 13:00, 15:00, 17:00, 22:00, 02:00, and 06:00 employing Goldmann and Perkins tonometry on habitual position. During the course of 1 year, 18 patients completed the study.

RESULTS

Monitoring of IOP on HD day showed a significantly higher mean 24-hour IOP (15.4 ± 2.7 vs 14.1 ± 2.2 mm Hg; p = 0.025), higher mean peak 24-hour IOP (18.5 ± 3.5 vs 15.8 ± 2.5 mm Hg; p = 0.003), and wider 24-hour IOP fluctuation (6.2 ± 2.3 vs 4.0 ± 1.9 mm Hg; p = 0.001). When individual time points were compared, IOP was significantly higher at 17:00 on HD day, reflecting a gradual IOP elevation during HD (p = 0.021). Further, during the HD procedure (13:00-17:00), the mean IOP was significantly higher on a HD day (16.4 ± 3.0 vs 14.7 ± 2.4 mm Hg; p = 0.004).

CONCLUSIONS

This prospective, before/after trial suggests that HD significantly impacts 24-hour IOP characteristics in normotensive eyes. The long-term significance of these findings requires further elucidation in normotensive patients and, predominantly, in patients with glaucoma undergoing HD.

Circadian intraocular pressure patterns in healthy subjects, primary open angle and normal tension glaucoma patients with a contact lens sensor

PURPOSE

To examine the circadian intraocular pressure (IOP) patterns in healthy subjects, in primary open angle and normal tension glaucoma (POAG; NTG) using a contact lens sensor (CLS; Sensimed Triggerfish, Lausanne, Switzerland).

METHODS

This was an observational, nonrandomized study. Ten healthy subjects (Group 1, 10 eyes) and 20 glaucomatous patients [20 eyes, 10 with POAG (Group 2) and 10 with NTG (Group 3)] were enrolled. All patients were controlled with prostaglandin analogues. The 24-hr IOP pattern was the main outcome. The morning (6AM-11AM), afternoon/evening (noon-11PM) and night (midnight-5AM) subperiod patterns, peaks and prolonged peaks (>1 hr) were secondary outcomes.

RESULTS

Mean 24-hr IOP pattern showed a nocturnal acrophase in all groups. Patterns were significantly different among groups (p = 0.02), with highest nocturnal IOP values in POAG. Prolonged peaks were more common in patients with glaucoma (70%) than in healthy subjects (33.3%) (p < 0.001). Significant differences were found for Groups 2 and 3 in the morning versus afternoon/evening (p = 0.019 and p = 0.035, Bonferroni correction), morning versus night (p = 0.005 and p < 0.0001) and afternoon/evening versus night periods comparisons (p < 0.0001 for both groups). In Group 1, patterns significantly differed in the morning versus night and afternoon/evening versus night period comparisons (p < 0.0001).

CONCLUSIONS

Continuous 24-hr IOP monitoring with the CLS revealed a nocturnal acrophase in healthy subjects and, more markedly, in glaucoma. Because the diurnal IOP profile seems not to predict the nocturnal rhythm, the circadian IOP pattern should be evaluated in clinical practice. These findings may be worthwhile for the management of glaucoma.

Comparison of the effects of bimatoprost and a fixed combination of latanoprost and timolol on 24-hour blood and ocular perfusion pressures: the results of a randomized trial

BACKGROUND

To compare the effect of bimatoprost and the fixed combination latanoprost-timolol (LTFC) on 24-hour systolic (SBP) and diastolic (DBP) blood pressure and on 24-hour ocular perfusion pressure (OPP).

METHODS

200 patients with glaucoma or ocular hypertension, controlled on the unfixed combination of latanoprost and timolol or eligible for dual therapy being not being fully controlled on monotherapy were enrolled in a randomized, double-masked, placebo-controlled, multicentre clinical trial. They were randomized to LTFC (8 a.m.) or bimatoprost (8 p.m.) and received 24-hour IOP curve at baseline, 6 and 12 weeks (supine and sitting position IOPs were recorded at 8 p.m., midnight, 5 a.m., 8a.m., noon and 4 p.m.). Holter 24-hour blood pressure curve was obtained between weeks 2 and 12. SBP, DBP, OPP were calculated and compared with ANOVA. Rates of diastolic OPP (DPP)≤50, ≤40, ≤30 mmHg in the 2 groups were calculated and compared using Fisher's test.

RESULTS

Mean baseline SBP and DBP were 136.5±18.3 vs 134.2±20.1 mmHg (p=0.1) and 79.1±10.2 vs 78.2±10.1 mmHg (p=0.4) in the bimatoprost and LTFC groups respectively. Holter SBP was significantly higher for bimatoprost (135.1 mmHg vs 128.1 mmHg, p=0.04), while no statistically significant difference in DBP was found. DPP was similar in the 2 groups, and proportions of patients with at least one value of the 24-hour curve≤50, ≤40, ≤30 mmHg were 94%, 86%, 41% respectively.

CONCLUSIONS

Bimatoprost and LTFC had similar DBPs and OPPs; SBP was significantly lower with LTFC. In this study, the percentage of "dippers" was considerably higher than the one described in previous studies on the role of perfusion pressure in glaucoma.

TRIAL REGISTRATION

NCT02154217, May 21, 2014.

''The association of normal tension glaucoma with Buerger's disease: a case report''

BACKGROUND

To report a case of a 48-year-old man with Buerger's disease who presented with bilateral normal-tension glaucoma (NTG).

CASE PRESENTATION

A 48-year-old man who had been diagnosed with Buerger's disease 12 years ago, and received bilateral below-the-knee amputations for ischemic ulcers of the lower limbs, presented at our clinic due to a sudden loss of visual acuity in the left eye. A fundus exam revealed a cup-to-disc ratio of 0.5 for the right eye and 0.8 for the left eye, arteriolar constriction in both eyes, retinal edema in the inferopapillary area, and splinter hemorrhages and soft exudate in the left eye. We diagnosed the patient as having acute nasal branch retinal artery occlusion in the left eye and bilateral NTG, as a result of the ophthalmologic examination and the other findings.

CONCLUSION

Although the pathomechanism of NTG is still unknown, previous studies have suggested that patients with NTG show a higher prevalence of vasospastic disorders. We present the second report of NTG associated with Buerger's disease to be described in the literature.

Instability of 24-hour intraocular pressure fluctuation in healthy young subjects: a prospective, cross-sectional study

Background

Elevated intraocular pressure (IOP) is a major risk factor for the development and/or progression of glaucoma, and a large diurnal IOP fluctuation has been identified as an independent risk factor of glaucoma progression. However, most previous studies have not considered the repeatability of 24-hour IOP measurements. The aim of this study was to evaluate the instability of 24-hour IOP fluctuations in healthy young subjects.

Methods

Ten healthy young volunteers participated in this prospective, cross-sectional study. Each subject underwent 24-hour IOP and systolic/diastolic blood pressure (SBP/DBP) assessments both in sitting and supine positions every 3 hours, once a week for 5 consecutive weeks. Mean ocular perfusion pressure (MOPP) was then calculated for both positions. The intraclass correlation coefficients (ICCs) of maximum, minimum, and fluctuation parameters were computed for IOP, SBP/DBP, and MOPP. Fluctuation was defined as the difference between maximum and minimum values during a day.

Results

Among the serial measurements taken over a 24-hour rhythm, the maximum/minimum values of IOP, as well as BP, showed excellent agreement: regardless of position, all ICC values were over 0.800. Most of the BP fluctuation values also showed excellent agreement. IOP fluctuation, however, did not show excellent agreement; the ICC of sitting IOP fluctuation was just 0.212. MOPP fluctuation also showed poor agreement, especially in the sitting position (ICC, 0.003).

Conclusion

On a day to day basis, 24-hour IOP fluctuations were not highly reproducible in healthy young volunteers. Our results imply that a single 24-hour IOP assessment may not be a sufficient or suitable way to characterize circadian IOP fluctuations for individual subjects.

Longitudinal stability of the diurnal rhythm of intraocular pressure in subjects with healthy eyes, ocular hypertension and pigment dispersion syndrome

Background

The diurnal fluctuation of intraocular pressure may be relevant in glaucoma. The aim of this study was to find out whether the timing of diurnal fluctuation is stable over the years.

Methods

Long-term IOP data from the Erlangen Glaucoma Registry, consisting of several annual extended diurnal IOP profiles for each patient, was retrospectively analyzed. Normal subjects, patients with ocular hypertension and with pigment dispersion syndrome were included because these subjects had not been treated with antiglaucomatous medications at the time of data acquisition. A cosine curve was fitted to the IOP data and the stability of individual rhythms over the years was tested using the Rayleigh test. To compare the peak times among groups, means were calculated only from subjects with a significant Rayleigh test.

Results

Of the fifty-two eligible subjects, a total of 364 extended diurnal IOP profiles measured in a sitting position had been collected over a period of 114 ± 39 months. The Rayleigh test indicated intraindividual stability of phase timing only in 19 subjects (36%). In subjects with pigment dispersions syndrome, peak IOP occurred on average two hours and seven minutes later during the day compared with subjects without this condition (p = 0.05).

Conclusions

Fitting of cosine curves to the clinical IOP profiles was generally feasible, although careful interpretation is warranted due to lack of measurements in supine position and between midnight and 7 am. The interesting observation of a phase lag in eyes with pigment dispersion syndrome warrants confirmation and exploration in future prospective studies. The analysis of the IOP data showed no stable individual rhythm in the long term in a majority of patients.

Efficacy and safety of switching to latanoprost 0.005%-timolol maleate 0.5% fixed-combination eyedrops from an unfixed combination for 36 months

Purpose

We prospectively investigated the intraocular pressure (IOP)-reducing effect, the visual field-maintenance effect, and the adverse reactions caused by administration of latanoprost/timolol maleate fixed-combination eyedrops for 3 years.

Subjects and methods

The subjects were 162 patients (162 eyes) with glaucoma or ocular hypotension who were using latanoprost and timolol maleate eyedrops concomitantly. The latanoprost and timolol maleate eyedrop regimen was discontinued without any washout period and subsequently changed to a latanoprost–timolol maleate fixed-combination eyedrop regimen. IOP values before the change and at 6, 12, 18, 24, 30, and 36 months after the change were measured and compared. The Humphrey visual field test was conducted before the change and at 12, 24, and 36 months after the change, and mean-deviation values were compared. Adverse reactions were assessed at every checkup.

Results

The IOPs before the change and at 6–36 months after the change were 15.2±3.3 mmHg and 14.3–15.2 mmHg, respectively, and a significant decrease was observed at 36 months after the change (P<0.01). Mean-deviation values before the change and at 12–36 months after the change were −9.11±6.94 dB and −10.08 to −9.22 dB, respectively, and these values were not significantly different (P=0.2148). Within the 36-month period, the eyedrops were discontinued because of insufficient IOP decrease in 33 cases (20.4%) and adverse reactions in eleven cases (6.8%).

Conclusion

IOP and the visual field were maintained for 3 years when a latanoprost and timolol maleate eyedrop regimen was changed to a latanoprost–timolol maleate fixed-combination eyedrop regimen. However, administration of the latanoprost–timolol maleate fixed-combination eyedrops was discontinued in approximately 27% of cases because of insufficient IOP decrease and adverse reactions.

Intraocular pressure curves of untreated glaucoma suspects and glaucoma patients in sitting and lateral decubitus positions using the goldmann applanation tonometer

PURPOSE

Evaluation of data obtained during diurnal intraocular pressure (IOP) measurements by means of the Goldmann Applanation tonometer in sitting and lateral decubitus positions.

PATIENTS AND METHODS

Retrospective cohort study of 41 consecutive untreated subjects (82 eyes) with ocular hypertension or suspicious discs. The IOP was measured by Goldmann Applanation tonometer in sitting position at 9 AM, 12 AM, 3 PM, and 6 PM; and in right lateral decubitus position around 12:15 PM.

RESULTS

In the right eye (RE) mean peak IOP was 22.19±4.68 mm Hg. In the left eye (LE) peak mean IOP was 22.19±3.8 mm Hg. In 91.5% of the eyes, the IOP increased in the lateral decubitus position. The average change in the RE was an increment of 4.22±2.67 mm Hg (P<0.001) and in the LE an increment of 3.51±3.11 (P<0.001). This increment was significantly higher in the dependent eye (i.e., lower eye) (P=0.049). Sixty-seven percent of eyes had a positional elevation of IOP between 2 and 5 mm Hg and 23.2% of eyes had IOP elevation between 6 and 12 mm Hg. In the great majority of the eyes (80.5% RE and 78% LE) the lateral decubitus IOP was greater than maximal diurnal sitting IOP.

CONCLUSIONS

The IOP in the lateral decubitus position was significantly higher than the mean maximal diurnal sitting IOP. Over 20% of the patients had an IOP increase of ≥6 mm Hg when lying down. Timely identification of patients with excessive postural elevation of IOP could affect their management and prevent visual fields loss.

Short- and long-term phasing of intraocular pressure in stable and progressive glaucoma

AIMS

To evaluate short- (ST) and long-term (LT) intraocular pressure (IOP) in patients with stable (SG) and progressive glaucoma (PG).

MATERIALS AND METHODS

Fifty-two patients with treated glaucoma received a baseline 24-hour IOP curve and, every 6 months for 2 years, office-hour curve plus visual field test. Based on field changes, they were divided into 24 SG and 28 PG. ST and LT IOP mean, peak and fluctuation (standard deviation of measurements) were calculated. Parameters determining progression were evaluated by logistic regression.

RESULTS

At ST, SG and PG, respectively, had mean IOP of 16.8 ± 2.2 and 15.3 ± 1.8 mm Hg; peak of 19.7 ± 3.3, 17.4 ± 2.3 mm Hg; fluctuation of 2.3 ± 1.2, and 1.6 ± 0.6 mm Hg. LT parameters did not change in SG, whereas a significant increase of mean (+1.0 ± 1.5 mm Hg, p = 0.05), peak (2.0 ± 2.4 mm Hg, p = 0.0002), and fluctuation (0.5 ± 1.1 mm Hg, p = 0.008) occurred in PG. Mean, peak, and fluctuation were correlated, except mean and fluctuation in the long term. Association with progression was shown for change in mean IOP between ST and LT, and ST peak.

CONCLUSIONS

SG and PG may show different IOP parameters when intensively measured at baseline and follow-up. Mean IOP change between ST and LT periods and ST peak were the parameters associated with progression.

24-hour intraocular pressure and ocular perfusion pressure in glaucoma

This review analyzes the currently available literature on circadian rhythms of intraocular pressure (IOP), blood pressure, and calculated ocular perfusion pressure (OPP) in patients with open-angle glaucoma. Although adequately powered, prospective trials are not available. The existing evidence suggests that high 24-hour IOP and OPP fluctuations can have detrimental effects in eyes with glaucoma. The currently emerging continuous IOP monitoring technologies may soon offer important contributions to the study of IOP rhythms. Once telemetric technologies become validated and widely available for clinical use, they may provide an important tool towards a better understanding of long- and short-term IOP fluctuations during a patient's daily routine. Important issues that need to be investigated further include the identification of appropriate surrogate measures of IOP and OPP fluctuation for patients unable to undergo 24-hour measurements, the determination of formulae that best describe the relationship between systemic blood pressure and IOP with OPP, and the exact clinical relevance of IOP and OPP fluctuation in individual patients. Despite the unanswered questions, a significant body of literature suggests that OPP assessment may be clinically relevant in a significant number of glaucoma patients.

Peak intraocular pressure and glaucomatous progression in primary open-angle glaucoma

PURPOSE

To evaluate the effect of 24-h peak intraocular pressure (IOP) on the progression of primary open-angle glaucoma (POAG) and the 24 h time points that best predict peak pressure.

METHODS

A retrospective analysis of clinical data evaluating long-term glaucomatous progression in patients with POAG who were previously in a 24-h study of the authors (IOP readings at 2/6/10 A.M. and 2/6/10 PM); had ≥3 treated 10 A.M. (±1 h) IOP measurements over 5-years after an untreated 24-h baseline; and had a treated 24-h curve with a 10 A.M. IOP±2 mmHg within the 10 A.M. mean IOP over 5-years.

RESULTS

We included 98 nonprogressed and 53 progressed patients with POAG (n=151). The mean 24-h peak IOP (mmHg) was 19.9±2.7 for progressed and 18.3±2.0 for nonprogressed patients (P<0.001). Progressed patients also showed a higher mean 24-h IOP. Generally, patients with a mean or peak daytime (readings at 10 A.M., 2 and 6 P.M.) or 24-h peak IOP of ≤18 remained nonprogressed in 75%-78% of cases. Further, measuring IOP at night found a higher peak in only 20% of cases, which was ≤2 of the daytime peak in 98% of cases. A multivariate regression analysis showed only 24-h peak IOP as an independent risk factor for progression (P=0.002).

CONCLUSIONS

This study suggests that daytime peak IOP may be clinically important in predicting long-term glaucomatous progression. Further, daytime peak IOP may assist, as much as daytime mean IOP and, in most cases, 24-h peak IOP, in helping to guide long-term treatment in POAG.