Diurnal Intraocular Pressure Curve Research Articles

Use of machine learning to predict the risk of early morning intraocular pressure peaks in glaucoma patients and suspects.

To use machine learning to predict the risk of intraocular pressure peaks at 6 a.m. in primary open-angle glaucoma patients and suspects. This cross-sectional observational study included 98 eyes of 98 patients who underwent a 24-hour intraocular pressure curve (including the intraocular pressure measurements at 6 a.m.). The diurnal intraocular pressure curve was defined as a series of three measurements at 8 a.m., 9 a.m., and 11 a.m. from the 24-hour intraocular pressure curve. Two new variables were introduced: slope and concavity. The slope of the curve was calculated as the difference between intraocular pressure measurements at 9 a.m. and 8 a.m. and reflected the intraocular pressure change in the first hour. The concavity of the curve was calculated as the difference between the slopes at 9 a.m. and 8 a.m. and indicated if the curve was bent upward or downward. A classification tree was used to determine a multivariate algorithm from the measurements of the diurnal intraocular pressure curve to predict the risk of elevated intraocular pressure at 6 a.m. Forty-nine (50%) eyes had intraocular pressure measurements at 6 a.m. >21 mmHg, and the median intraocular pressure peak in these eyes at 6 a.m. was 26 mmHg. The best predictors of intraocular pressure measurements >21 mmHg at 6 a.m. were the intraocular pressure measurements at 8 a.m. and concavity. The proposed model achieved a sensitivity of 100% and a specificity of 86%, resulting in an accuracy of 93%. The machine learning approach was able to predict the risk of intraocular pressure peaks at 6 a.m. with good accuracy. This new approach to the diurnal intraocular pressure curve may become a widely used tool in daily practice and the indication of a 24-hour intraocular pressure curve could be rationalized according to risk stratification.

Сравнительная оценка суточных кривых ВГД у пациентов с осложненной катарактой на фоне псевдоэксфолиативного синдрома до и после факоэмульсификации с имплантацией ИОЛ

Purpose. To perform a comparative analysis of the 24-hour control of intraocular pressure (IOP) amplitudes in patients with complicated cataract associated with PEX before and after phacoemulsification of cataract. Material and methods. The clinical study was carried out in 154 eyes of 154 patients with cataract associated with pseudoexfoliation syndrome (PEX). All patients diagnosed with cataract associated with PEX were divided into 3 groups: the group 1 included patients with normal IOP level preoperatively (n=55); the group 2 included patients with IOP ophthalmohypertension preoperatively (n=57); the group 3 included patients with primary open-angle initial glaucoma (n=42). The study of the amplitude of 24-hour fluctuations of IOP and diurnal curve of IOP before and after cataract phacoemulsification was performed. Before the PHACO+IOL the amplitude of diurnal IOP fluctuations was in the group 1: 5.22±0.49 mm Hg, and in the groups 2 and 3: 6.81±1.21 mmHg and 6.60±1.49 mm Hg, respectively. Results. Patients of the group 1 had a significant decrease in the amplitude of diurnal IOP fluctuations by 1.27±0.93 mm Hg (p<0.001). A decrease in the amplitude of diurnal IOP fluctuations by 2.34±1.26 mm Hg (p<0.001) was noted in patients of the group 2. In the group 3 a decrease in the amplitude of diurnal IOP fluctuations by 1.15±1.14 mm Hg (p<0.001) was observed. A tendency of changes in diurnal IOP curves after surgery was revealed in all cases. Conclusion. PHACO+IOL in patients with cataract associated with PEX allows to normalize the level, amplitude and type of diurnal IOP curve.

Effects of different types of music on intraocular pressure and the underlying mechanism

Objective: To explore the effect of listening to different types of music on intraocular pressure (IOP) and the underlying mechanism. Methods: Cross-sectional study. Participants were students from Sun Yat-sen University from October 2017 to May 2018. The study consisted of two parts. In part 1, three types of music, including relaxing, positive and negative music, were used to find out which kind of music could reduce IOP. IOP was measured before and after listening to music. A self-report questionnaire was used to evaluate emotional responses to each type of music. In part 2, the diurnal curve of IOP at 6 time points of 7:30, 9:30, 11:30, 13:30, 15:30 and 17:30 was measured to determine when the individual's IOP peaked. On the second day, the subject listened to the music that could reduce IOP for 15 minutes at his/her IOP peak time. IOP, blood pressure (BP) and heart rate (HR) were measured, and morphology of the chamber angle was captured by swept-source optical coherence tomography before and after listening to music. Image J software was used to measure the diameter and cross-sectional area of Schlemm's canal (SC). Paired t-test was used to compare BP, HR and SC measurements prior to and post-music intervention. Results: In part 1, fifteen subjects, including 7 males and 8 females, were enrolled, with an average age of (23±1) years. Relaxation music could significantly lower IOP [(11.62±2.51) vs. (12.65±2.49) mmHg (1 mmHg=0.133 kPa) , t=-2.39, P=0.032]. Positive music had no effect on IOP [(12.45±2.77) vs. (12.65±2.46) mmHg, P=0.566] and negative music increased IOP [(12.13±1.60) vs. (10.86±2.78) mmHg, t=2.45, P=0.029]. Relaxation music could also arouse relaxation emotions in 14 out of 15 subjects. In part 2, 55 subjects, including 20 males and 35 females, were enrolled, with an average age of (26±10) years. The diurnal curve of IOP at 6 time points of every participant was measured. At each individual's peak time point, listening to relaxation music could decrease IOP [(12.66±4.32) vs. (13.99±4.47) mmHg, t=-5.72, P<0.01]. HR before and after listening to relaxation music was (79.57±10.43) and (75.57±9.62) beats/min, respectively (t=-3.68, P=0.001). Systolic BP was (118.11±13.92) and (110.82±12.67) mmHg, respectively (t=-5.10, P<0.01). Diastolic BP significantly declined from (70.07±9.96) to (66.14±8.48) mmHg (t=-3.65, P=0.001). Average SC area significantly increased after listening to relaxation music [(255.96±93.36) vs. (230.07±92.20) pixels, t=2.88, P=0.006]. Average SC diameter was (8.62±1.89) and (9.41±2.37) pixels, respectively before and after listening to relaxation music (t=3.39, P=0.001). Conclusion: Relaxation music reduces IOP in healthy subjects probably by dilating the SC.(Chin J Ophthalmol, 2020, 56: 25-31).

A Pilot Evaluation Assessing the Ease of Use and Accuracy of the New Self/Home-Tonometer IcareHOME in Healthy Young Subjects

We investigated the ease of use and accuracy of a new self/home-tonometer (IcareHOME) versus Goldmann applanation tonometry (GAT) and the Icare tonometer (Icare) by measuring the diurnal intraocular pressure (IOP). The right eyes of 43 healthy young subjects were studied. The IOP was measured using the IcareHOME, GAT, and Icare 6 times a day, every 2 hours, from 8:00 to 18:00. The coincidence of the diurnal curves among all tonometers was analyzed using a linear mixed model. The intradevice and interdevice agreement was evaluated using the intraclass correlation coefficients (ICC) and Bland-Altman method. The subjects' perception of the IcareHOME was evaluated using a questionnaire. The liner mixed model showed similar diurnal IOP curves for all tonometers (P=0.543); however, significant differences were observed between the tonometers over time (P<0.001). The intradevice repeatability was ICC>0.8 among all tonometers, although the interdevice agreement was lowest between the IcareHOME and GAT (ICC=0.641). The IOP values were significantly lower for the IcareHOME than for the GAT at 12:00, 16:00, and 18:00 (P<0.05, Tukey-Kramer test). The mean differences between the Icare and IcareHOME and GAT and IcareHOME were 0.83 and 1.03 mm Hg, respectively (95% limit of agreement: -4.17 to 5.84 mm Hg and -3.91 to 5.98 mm Hg, respectively). Regarding the subjects' perception of handling the IcareHOME, 17 (39.5%) subjects answered "easy to use," 20 (46.5%) answered "normal," and six (13.9%) answered "difficult to use." The IcareHOME can be used as a self/home-tonometer; however, it may result in lower IOP values.

Diurnal Curve of the Ocular Perfusion Pressure.

ABSTRACTPurpose: To describe the diurnal variation of the ocular perfusion pressure (OPP) in normal, suspects and glaucoma patients.Materials and methods: Seventy-nine subjects were enrolled in a prospective study. The diurnal curve of intraocular pressure (IOP) was performed and blood pressure measurements were obtained. Each participant was grouped into one of the following based upon the clinical evaluation of the optic disk, IOP and standard achromatic perimetry (SAP): 18 eyes were classified as normal (normal SAP, normal optic disk evaluation and IOP < 21 mm Hg in two different measurements), 30 eyes as glaucoma suspect (GS) (normal SAP and mean deviation (MD), C/D ration > 0.5 or asymmetry > 0.2 and/or ocular hypertension), 31 eyes as early glaucoma (MD < -6 dB, glaucomatous optic neuropathy and SAP and MDs on SAP. Standard achromatic perimetry was performed with the Octopus 3.1.1 Dynamic 24-2 program. Intraocular pressure and blood pressure measurements were taken at 6 am, 9 am, 12, 3 and 6 pm. The patients stayed in the seated position for 5 minutes prior to blood pressure measurements.Results: The mean IOP values in all groups did not follow any regular pattern. The peak IOP was found to be greater in suspect [18.70 ± 3.31 (mm Hg ± SD)] and glaucoma (18.77 ± 4.30 mm Hg) patients as compared to normal subjects (16.11 ± 2.27 mm Hg). In studying the diurnal variation of the OPP, we found lower values at 3 pm in normals (34.21 ± 2.07 mm Hg), at 9 am in suspects (54.35 ± 3.32 mm Hg) and at 12 pm in glaucoma patients (34.84 ± 1.44 mm Hg).Conclusion: Each group has a specific OPP variation during the day with the most homogeneous group being the suspect one. It is important to keep studying the IOP and OPP variation for increased comprehension of the pathophysiology of glaucomatous optic neuropathy.How to cite this article: Kanadani FN, Moreira TCA, Bezerra BSP, Vianello MP, Corradi J, Dorairaj SK, Prata TS. Diurnal Curve of the Ocular Perfusion Pressure. J Curr Glaucoma Pract 2016;10(1):4-6.

Efficacy of preservative-free tafluprost in patients with normal-tension glaucoma previously treated with latanoprost.

Dear editor We read with interest the article entitled “Effects of tafluprost treatment for 3 years in patients with normal-tension glaucoma” by Inoue et al.1 In this study, the authors reported the efficacy of tafluprost in naive patients with normal-tension glaucoma (NTG) over 3 years of follow-up. The intraocular pressure (IOP)-lowering efficacy of tafluprost in NTG has been recently reported by Mizoguchi et al2 and Nakano et al.3 Whereas tafluprost is available in Europe in a preservative-free formulation, the three aforementioned studies1–3 were all carried out in Japan, where tafluprost is on the market as a benzalkonium chloride (BAK)-containing formulation. Recent literature reported BAK-related ocular surface inflammation and epithelial damage,4 which led to the development of preservative-free antiglaucoma drugs. The cytotoxic effect of BAK on conjunctival and corneal epithelium has been claimed to increase ocular penetration of topical drug, enhancing the therapeutic effect.5 As the presence of preservative may play a role in the IOP-lowering effect, we believe it is of interest to report the efficacy of BAK-free formulations in NTG. In a previous study by our group, BAK-free tafluprost showed a comparable efficacy to other prostaglandin analogs, with a safe profile in patients with primary open-angle glaucoma.6 In this letter, we want to report our experience with preservative-free tafluprost in patients with NTG. Herein, we present a retrospective study on 58 eyes of 58 patients (mean age 65.8±9.2 years, range 43–91 years) with NTG previously treated with BAK-preserved latanoprost who were switched to unpreserved tafluprost for ocular surface discomfort. The study was carried out with approval from the Institutional Ethics Committee (San Giuseppe Hospital, MultiMedica) and adhered to the tenets of the Declaration of Helsinki. To be included, patients had to have unilateral or bilateral NTG. Diagnosis of NTG was made on the basis of optic-disk abnormalities and visual-field defects judged by a trained glaucoma specialist to be characteristic of glaucoma with IOP <21 mmHg at any time points of the diurnal IOP curve (8 am, 11 am, 2 pm, 5 pm). All patients were followed in our hospital (San Giuseppe Hospital) from January 2011 to December 2013. Inclusion criteria were: at least 3 months of treatment with BAK-preserved latanoprost followed by at least 3 months of treatment with unpreserved tafluprost; switch to tafluprost due to ocular discomfort; and availability of data from three diurnal IOP curves (untreated, treated with latanoprost, and after switch to tafluprost). Both latanoprost and tafluprost significantly reduced the diurnal mean IOP compared to baseline (12.7±1.7 mmHg versus 14.9±1.9 mmHg, −15%, P<0.001 and 12.2±1.8 mmHg versus 14.9±1.9 mmHg, −18%, P<0.001, respectively) (Figure 1). Conjunctival hyperemia was reported in 17% and 8% of patients and fluorescein corneal staining in 6% and 2% of patients receiving latanoprost and tafluprost, respectively. Figure 1 Intraocular pressure at baseline, with latanoprost, and after switch from latanoprost to tafluprost. The retrospective nature of this study, the absence of a wash-out period, and the short follow-up are all limitations of this report and we are aware that our results need to be confirmed by powered, prospective, randomized clinical trials. However, to the best of our knowledge, this is the first report on the efficacy of BAK-free tafluprost in NTG. In our study, the percentage IOP reduction from untreated baseline for both latanoprost (15%) and tafluprost (18%) was similar to that reported in other studies investigating the efficacy of prostaglandin analogs in NTG and ranging from 16%7 to 19%.8 This study suggests the effectiveness of preservative-free tafluprost in NTG, showing results comparable to those obtained in Japanese patients1–3 using a BAK-preserved formulation.

Long-Term Reproducibility of Diurnal Intraocular Pressure Patterns in Patients with Glaucoma

To evaluate the long-term reproducibility of diurnal intraocular pressure (IOP) patterns in patients with primary open-angle glaucoma (POAG). Database study. Ninety-two patients with POAG. We reviewed the records of patients with POAG who underwent 4 diurnal IOP curve measurements 6 months apart with Goldmann applanation tonometry recorded in the sitting position at 9 am, 10 am, 11 am, noon, 2 pm, 3 pm, 4 pm, and 5 pm. Intervisit agreement of IOP by time point and of diurnal IOP curve parameters (mean, standard deviation, range, maximum, maximum hour, minimum, and minimum hour) was assessed using intraclass correlation coefficients (ICCs). Analyses were performed in all eyes and separately in eyes with and without hypotensive medications, and in eyes naïve and non-naïve of filtering surgery. Between-visit agreement of IOP values at each time point was generally poor, with ICCs ranging from 0.26 to 0.77 in all patients (1 of 8 time points with ICC >0.75), from -0.07 to 0.60 in patients without hypotensive medications (zero time points with ICC >0.75), from 0.29 to 0.80 in patients with hypotensive medications (3 time points with ICCs >0.75), from 0.21 to 0.68 in filtering surgery-naïve patients (zero time points with ICC >0.75), and from 0.21 to 0.87 in patients with previous filtering surgeries (5 time points with ICCs >0.75). The predictive value of the first diurnal IOP curve to estimate the risk of IOP fluctuations during the 3 subsequent curves was limited (only 6.4% of the patients with an IOP range ≥30% of the mean IOP on the first curve presented similar fluctuations on the 3 subsequent curves; 77.1% of the patients who did not have an IOP range ≥30% of the mean IOP on the first curve had an IOP range ≥30% of the mean IOP on at least 1 of the 3 subsequent curves). Patients with POAG do not manifest a reproducible diurnal IOP pattern from month to month. A single diurnal IOP curve in patients with POAG poorly characterizes IOP fluctuations and has limited value in clinical practice.

The therapeutic impact of office‐hours diurnal pressure measurements in the management of glaucoma patients

AbstractPurpose To assess, primarily, the impact of office‐hours diurnal IOP measurements on our clinical treatment attitude for glaucoma patients. Secondly, to determine, specific risk factors which allow us to select the group of patients where performing an IOP diurnal curve can be useful.Methods 20 patients were included in this retrospective study. We examined the files of the patient who underwent a diurnal IO pressure curve between 01/01/2012 and 01/03/2013. Age, gender, race, diagnosis, the ophthalmological surgical and medical history, number of IOP measurements and the length of the diurnal curve on the examination day, the min and max IOP, and finally the therapeutic impact of these measurements and change in the treatment of patients.Results The mean age was 58.6 ± 14.8 years. There was min 4 to max 5 IOP measurements during 8.4 ± 0.5 hours. The mean IOP of all the patients was 17.7 ± 3.2 mmHg with a variation 2.3 ± 1.4 mmHg (1 to 6 mmHg max) during the day. There were only 50% of the measurements which led to a change of the clinical treatment. In this group of patients the higher max IOP during the day and the higher IOP variation were the common feature.Conclusion In our study we found that only 50% of the office‐hours diurnal intraocular pressure curve led to a new clinical treatment. The patient selection should be stricter because of the time‐consuming examination. Patients with higher IOP should be taken into account for diurnal IOP measurements where there are signs of progression.

Periodic analysis using two-way analysis of variance for the circadian rhythm of intraocular pressure in primary open angle glaucoma

The purpose of the article is to investigate the diurnal variation of intraocular pressure (IOP) in glaucoma patients by periodic regression analyses using two-way analysis of variance (ANOVA). Seventy-two open-angle glaucoma patients participated in this study and IOP measurements were taken in this group every 2 h during waking hours. Patients were categorized based on the Glaucoma staging system (GSS) into “severe” (GSS > stage 2) and “less severe” (GSS ≤ stage 2) groups. They were also categorized into high tension (IOP ≥ 19 mmHg) and low tension (IOP < 19 mmHg) groups. Diurnal IOP curves were plotted and analyzed for all patients and for each subgroup by periodic regression analysis with two-way ANOVA. Results showed that all diurnal IOP curves from all patients and all subgroups statistically fitted periodic regression curves within a 24-h period (p < 0.0001, two-way ANOVA for all categories). It is concluded that IOP exhibits a 24-h circadian rhythm in glaucoma patients during waking hours.

Intraocular Pressure-Lowering Effects of Commonly Used Fixed-Combination Drugs with Timolol: A Systematic Review and Meta-Analysis

BackgroundThe first goal of medical therapy in glaucoma is to reduce intraocular pressure (IOP), and the fixed-combination medications are needed to achieve sufficiently low target IOP. The aim of this systematic review and meta-analysis is to evaluate IOP-lowering effect of the commonly used fixed-combination drugs containing 0.5% timolol.MethodsPertinent publications were identified through systematic searches. Over 85% of the patients had to be diagnosed with primary open-angle glaucoma (POAG) or ocular hypertension (OHT). Forty-one randomized clinical trials were included in the meta-analysis. The main efficacy measures were the absolute and relative values of mean diurnal IOP reduction, and the highest and lowest IOP reductions on the diurnal IOP curve. The pooled 1- to 3-month IOP-lowering effects after a medicine-free washout period was calculated by performing meta-analysis using the random effects model, and relative treatment effects among different fixed combinations were assessed using a mixed-effects meta-regression model.ResultsThe relative reductions for mean diurnal IOP were 34.9% for travoprost/timolol, 34.3% for bimatoprost/timolol, 33.9% for latanoprost/timolol, 32.7% for brinzolamide/timolol, 29.9% for dorzolamide/timolol, and 28.1% for brimonidine/timolol. For the highest IOP decrease, relative reductions ranged from 31.3% for dorzolamide/timolol to 35.5% for travoprost/timolol; for the lowest IOP decrease, those varied from 25.9% for dorzolamide/timolol to 33.1% for bimatoprost/timolol. Both latanoprost/timolol and travoprost/timolol were more effective in lowering mean diurnal IOP than brimonidine/timolol (WMD: 5.9 and 7.0) and dorzolamide/timolol (WMD: 3.8 and 3.3).ConclusionsAll six commonly used fixed-combination drugs containing timolol can effectively lower IOP in patients with POAG and OHT, and both latanoprost/timolol and travoprost/timolol might achieve better IOP-lowering effects among the six fixed-combination agents.

Physiologie der Kammerwasserproduktion sowie der Tagesdruckschwankungen und deren Bedeutung für das Glaukom

In the human eye there is a balance between production of aqueous humor as well as its drainage. The intraocular pressure is held through different mechanisms in a stable balance. The aqueous humor is secreted by the ciliary epithelium lining the ciliary processes. Three physiological processes contribute to the formation and chemical composition of the aqueous humor: diffusion (5 %), ultrafiltration (15 %) and active secretion (80 %). The normal intraocular pressure amounts to 15 ± 3 mmHg, the normal diurnal fluctuation 5 mmHg. Aqueous humor leaves the eye by passive bulk flow via two pathways: the trabecular route and the uveoscleral route. In glaucoma patients this balance is disturbed resulting in individual high intraocular pressure or, respectively, high diurnal fluctuations. This leads to loss of retinal ganglion cells and visual field loss. As a recommendation for glaucoma patients it is useful to construct diurnal intraocular pressure curves to evaluate the "type of pressure" and to determine the diurnal fluctuations or, respectively, the time of the pressure maxima. With this knowledge, treatment of glaucoma patients can be managed in a more individualised manner and it seems to slow down the progress of the disease better than by merely reducing the intraocular pressure.

Association between Genetic Polymorphisms of Adrenergic Receptor and Diurnal Intraocular Pressure in Japanese Normal-Tension Glaucoma

To evaluate the relationship between genetic polymorphisms of the adrenergic receptor (ADR) and diurnal intraocular pressure (IOP) in Japanese normal-tension glaucoma (NTG) patients. Prospective, comparative case series. Ninety-two untreated NTG patients. The IOP of both eyes was measured at 3-hour intervals from 0600 to 2400 hours over 2 consecutive days. We used IOP data from the eye with the greater visual field defect for statistical analysis. The mean IOP over 2 days was used for each time point. Genetic polymorphisms in α1A-, α2A-, α2B-, α2C-, β1-, β2-, and β3-ADR were determined mainly by direct DNA sequencing. The relationship between IOP and genetic polymorphisms was analyzed. The IOP and genotypes of genetic polymorphisms. Diurnal mean IOP of the subjects was 14.8 ± 2.1 mmHg (mean value ± standard deviation). For Del 301-303 in α2B-ADR, insertion/insertion (I/I) had a significantly higher diurnal mean IOP (P = 0.017), peak IOP (P = 0.038), and trough IOP (P = 0.046) than deletion (D) carriers. For Del 322-325 in α2C-ADR, I/I had a significantly lower diurnal mean IOP (P = 0.037) and peak IOP (P = 0.029) than D carriers. For S49G (A/G) in β1-ADR, A/A had a significantly higher diurnal mean IOP (P = 0.023), peak IOP (P = 0.019), and trough IOP (P = 0.014) than G carriers. For these 3 polymorphisms, repeated measures analysis of variance showed that the major homozygotes and minor carriers had parallel diurnal IOP curves, but significantly different diurnal IOP levels. Polymorphisms of the ADR gene may alter the untreated IOP level of patients with NTG.

The Intraocular Pressure-Lowering Effect of Prostaglandin Analogs Combined with Topical β-Blocker Therapy: A Systematic Review and Meta-analysis

To estimate the intraocular pressure (IOP)-lowering effect of prostaglandin analogs (PGAs) when added to topical β-blocker (BB) therapy. Systematic review and meta-analyses of randomized clinical trials. Twenty-nine articles reporting on 33 study arms and 3 control arms. Articles published between January 1, 1990, and August 18, 2009, were identified in relevant databases. The pooled IOP-lowering effects at the 1- to 3-month follow-ups were calculated by performing random effects meta-analyses. Absolute and relative change in IOP for mean diurnal curve and highest and lowest IOP decrease on the diurnal IOP curve. Adding 0.005% latanoprost in the evening to 0.5% timolol twice daily resulted in a pooled change of -6.3 mmHg (95% CI, -7.1 to -5.5 mmHg, mean IOP curve); switching to the fixed combination of 0.5% timolol and 0.005% latanoprost in the morning resulted in a pooled change of -2.8 mmHg (95% CI, -3.3 to -2.3 mmHg, mean IOP curve). Starting with any fixed combination of 0.5% timolol and a PGA in the morning resulted in a pooled change of -8.4 mmHg (95% CI, -9.1 to -7.6 mmHg, mean IOP curve) and varied between -9.1 mmHg (95% CI, -9.9 to -8.2 mmHg, highest) and -7.9 mmHg (95% CI, -8.5 to -7.2 mmHg, lowest); starting with any fixed combination of 0.5% timolol and a PGA in the evening resulted in a pooled change of -8.6 (95% CI, -9.2 to -8.0 mmHg, mean IOP curve) and varied between -10.1 mmHg (95% CI, -11.0 to -9.2 mmHg, highest) and -7.3 mmHg (95% CI, -8.1 to -6.4 mmHg, lowest). The concomitant use of latanoprost and timolol leads to a larger additional IOP reduction when compared with the fixed combination. There is no difference in mean IOP-lowering effect between evening and morning dosing of a fixed combination of timolol and a PGA, although the largest IOP decreases are seen with evening dosing. These findings are explained by differences in study design. When time points of IOP measurements close to the peak or trough moment of a drug are included, the IOP-lowering effect will be overestimated or underestimated, respectively. Proprietary or commercial disclosure may be found after the references.

The diurnal variation of intraocular pressure—the most important symptom for early detection and follow-up of the glaucomas

Hans Goldmann in 1958 emphasized the importance of the diurnal curve of intraocular pressure for very early detection of glaucoma. He stressed from the investigations of Leydhecker (1959) that there is a 10-year interval between early detection of chronic glaucoma and the first signs of neuronal defects or even later, functional problems. Roberto Sampaolesi (1974) finally has proven the important innovation from his great number of diurnal curves. Of course, a precise diurnal curve (Sampaolesi asked for eight measurements) is almost impossible by the ophthalmologist's office or even within the hospital. We need the cooperation of the patient (like we do this in blood pressure measurement or even diabetes control). This requires an easy-to-handle "self-tonometer", which allows measurement at any time of the day, even in different positions of the patient's body. Due to some difficult technical problems to be solved, it took until 1988 before the "automatic self-tonometer" was available. This was first tried in three space missions (Spacelab D1, 1985; Spacelab D2, 1993; German-Russian MIR-Mission 1992) allowing for the first time to register the enormous increase of intraocular and intracranial pressure after entering into microgravity. Some years later, the first instrument for clinical application was available, allowing a large series of dense diurnal curves, confirming Goldmann's and Sampaolesi's hypothesis. The technical solution, application, and results with this new instrument are described.

Influence of Selective Laser Trabeculoplasty on 24-Hour Diurnal Intraocular Pressure Fluctuation in Primary Open-Angle Glaucoma: A Pilot Study

To investigate the influence of selective laser trabeculoplasty on mean diurnal intraocular pressure (IOP) and diurnal IOP fluctuation in primary open-angle glaucoma. After washout from intraocular pressure-lowering drugs, a baseline diurnal IOP curve was obtained for 26 eyes of 13 patients before selective laser trabeculoplasty. The IOP curve was repeated at 3 and 6 months. In five eyes, office time (8:00 a.m. to 12:00 p.m.) IOP decreased by 20% or more. No similar decrease was seen in mean diurnal IOP in any case. IOP-lowering drugs were required for 11 eyes before the 3-month visit. Baseline diurnal IOP was higher for these eyes than for the others (P = .002). Compared with baseline values, a significant decrease was seen in mean IOP at the 6-month visit (P = .017) and in IOP fluctuation at both visits (P < .001 and P = .004, respectively) for the eyes without drug treatment. Although no eyes showed mean diurnal IOP reduction of 20% or more, selective laser trabeculoplasty resulted in a significant decrease in the amplitude of diurnal IOP fluctuation.

Visual Field and Intraocular Pressure Asymmetry in the Low-Pressure Glaucoma Treatment Study

To explore the relationship between asymmetric baseline intraocular pressure (IOP) and asymmetric visual field (VF) loss in the Low-Pressure Glaucoma Treatment Study. Randomized, multicenter, controlled clinical trial. Low-pressure glaucoma (LPG) patients 30 years or older were identified. Exclusion criteria included an untreated pressure > 21 mmHg, advanced VF loss, and contraindications to study medications. A baseline VF was created using the average of 2 reliable Humphrey full-threshold examinations. A baseline diurnal IOP curve was performed without IOP-lowering medication. Mean diurnal, peak, trough, IOP range (peak - trough), and standard deviation (SD) of IOP measurements, and mean deviation (MD) and corrected pattern SD (CPSD) of VF examinations. One hundred ninety patients were enrolled (mean age, 64.9+/-10.7 years). Mean deviation and CPSD were not correlated with mean, peak, trough, or peak minus trough (P - T) IOP (Ps = 0.2-0.9). Among patients with unilateral VF loss (n = 53 [27.9%]), there were no differences (Ps = 0.3-0.9) in any IOP parameter between the normal VF eye and fellow glaucomatous eyes. Among patients with bilateral VF loss (n = 137 [72.1%]), mean, peak, trough, and P - T IOPs were similar in eyes with a better VF MD compared with eyes with a worse VF MD (Ps = 0.2-0.7). Cross-classified contingency tables demonstrated no relationship (Ps = 0.1-0.3) between IOP and VF MD or CPSD using chi-square analysis. Intraocular pressure asymmetry is unrelated to VF asymmetry in the Low-Pressure Glaucoma Treatment Study, suggesting an unclear pathogenic relationship between IOP and glaucomatous damage in eyes with LPG.

Application du test de surcharge hydrique après sclérectomie profonde non perforante

Recent studies have demonstrated that the intraocular pressure peak obtained after water-drinking test is similar to the one after diurnal intraocular pressure curve. The aim of this study is to assess the intraocular pressure peaks, the amplitude of variation of intraocular pressure after the water-drinking test in patients submitted to a non penetrating deep sclerectomy, evaluating its capacity to avoid large intraocular pressure fluctuations in post-operative period. Ninety-seven eyes of ninety-seven patients were enrolled and divided in 5 groups: group I--20 non-glaucomatous individuals, group II--21 glaucomatous patients with no treatment, group III--15 glaucomatous patients under medical treatment (timolol 0.5% + dorzolamide in fixed combination), group IV--21 glaucomatous patients after non penetrating deep sclerectomy, and group V--20 glaucomatous patients after trabeculectomy. The water-drinking test was then applied to everyone and the authors have compared and analyzed the results, concerning the initial intraocular pressure, intraocular pressure peaks and intraocular pressure amplitude of variation. Mean age (+/- standard deviation) was 58.9 +/- 13.4 years. Mean initial intraocular pressure, mean intraocular peak and mean amplitude were, respectively: in group I: 13.9/15.8/1.9; in group II: 17.5/26.0/8.4; in group III: 14.2/18.6 4.3; in group IV: 12.3/14.1/1.7; in group V: 10.0/11.6/1.6. There was no statistical difference, concerning the intraocular pressure amplitude of variation, among the following groups: I, IV and V. The intraocular pressure variations after the water-drinking test are similar in non-glaucomatous individuals and in patients submitted to a penetrating filtering surgery, (trabeculectomy) or a non penetrating technique (deep sclerectomy). The water-drinking test demonstrated that these two filtering procedures are safe and efficient in avoiding intraocular pressure peaks and large fluctuations in glaucomatous patients.

Diurnal Intraocular Pressure Variation in Pseudoexfoliation Syndrome

To describe and compare the diurnal intraocular pressure (IOP) variation in patients with pseudoexfoliation syndrome (PXS) and normal subjects. The authors prospectively investigated 19 PXS patients (10 bilateral and 9 unilateral) and 25 age- and sex-matched normal subjects. One eye of each control subject and bilateral PXS patient was selected randomly, and pseudoexfoliative eyes of unilateral cases were enrolled in this study. All patients were admitted to the authors' ophthalmology department and underwent diurnal IOP testing (six measurements over 24 hours). The mean IOP of PXS patients at all time intervals was significantly higher than the control group (p<0.05). Likewise, a significant difference in the maximum IOP, range of IOP, and minimum IOP, as well as the standard deviation of the pressure at each time point, existed between groups (p<0.05). Normal individuals did not show diurnal variation greater than 5 mmHg. Of patients with PXS, 55.6% showed diurnal variation greater than 5 mm Hg. In addition, in 10% of patients with PXS, the diurnal variations were equal to or higher than 10 mmHg. Variations in IOP during the daily 24-hour cycle in patients with PXS were higher than control groups. Significant fluctuations in the diurnal curve of IOP in PXS may be an important factor in predicting eyes that may develop pseudoexfoliative glaucoma. IOP fluctuation could influence the diagnostic and prognostic evaluation of PXS.

The role of diurnal pressure measurements in the management of open angle glaucoma.

The measurement of intraocular pressure (IOP) is essential in the diagnosis and management of open-angle glaucoma, but a single measurement in the ophthalmologist's office may or may not reflect what the IOP is at other times of the day or night. It is well documented that the range of the daily fluctuations in IOP is greater in patients with glaucoma than in normal individuals, and a report by Asrani et al. suggested that the range of the diurnal fluctuation may be an independent risk factor for the progression of visual field loss. There have been reports of nocturnal increases in IOP, particularly in patients with normal tension glaucoma, and some ophthalmologists believe these may account for progression of visual field loss in some patients with glaucoma. This review will analyze recent articles that report the impact of various glaucoma therapies on the diurnal IOP curve and the use of diurnal curves in glaucoma diagnosis. A number of recent publications document that antiglaucoma medications with a long duration of action reduce the range of diurnal fluctuation more than the shorter duration medications. Laser trabeculoplasty and trabeculectomy also narrow the range of diurnal fluctuation, and at least one recent study finds that trabeculectomy reduces the diurnal range more than medical therapy does. Several recent studies of diurnal IOP in patients with glaucoma have failed to document such diurnal IOP spikes, so the published data available have not supported this hypothesis. One recent report has reconfirmed that a single IOP measurement in the office may not accurately indicate what is happening to the IOP of a patient with glaucoma throughout the day. Other reports have confirmed that treatment that lowers IOP narrows the range of diurnal IOP fluctuation, and one of these reports suggests that surgical reduction of IOL may narrow the fluctuation more than medical reduction of IOP. The reports of IOP during the night have not provided clear answers about what happens to IOP during sleep.

The effect of 0.12% unoprostone isopropyl (rescula) on intraocular pressure in normotensive dogs.

Rescula (0.12% unoprostone isopropyl) is the first docosanoid compound approved for treatment of glaucoma in humans. It is commercially available in Japan, and is undergoing clinical testing elsewhere. The aim of this study was to evaluate the effect of Rescula on intraocular pressure (IOP) in normotensive dogs. After establishing a baseline diurnal IOP curve, six dogs were unilaterally treated with Rescula while the contralateral eye was treated with a placebo. Applanation tonometry was performed in both eyes, and pupil size was evaluated, 30 min after treatment, and at 1-hr intervals for the next 9 hr. Rescula caused a significant (p=0.014) and long-lasting decrease in IOP, from 20.49+/-2.02 mm Hg in control eyes to 15.49+/-0.69 mm Hg in treated eyes. These results suggest that Rescula is potentially efficacious in treatment of canine glaucoma.