24-hour Intraocular Pressure Monitoring Research Articles

Predicting 24-hour intraocular pressure peaks and averages with machine learning.

Predicting 24-hour peak and average intraocular pressure (IOP) is essential for the diagnosis and management of glaucoma. This study aimed to develop and assess a machine learning model for predicting 24-hour peak and average IOP, leveraging advanced techniques to enhance prediction accuracy. We also aimed to identify relevant features and provide insights into the prediction results to better inform clinical practice. In this retrospective study, electronic medical records from January 2014 to May 2024 were analyzed, incorporating 24-hour IOP monitoring data and patient characteristics. Predictive models based on five machine learning algorithms were trained and evaluated. Five time points (10:00 AM, 12:00 PM, 2:00 PM, 4:00 PM, and 6:00 PM) were tested to optimize prediction accuracy using their combinations. The model with the highest performance was selected, and feature importance was assessed using Shapley Additive Explanations. This study included data from 517 patients (1,034 eyes). For predicting 24-hour peak IOP, the Random Forest Regression (RFR) model utilizing IOP values at 10:00 AM, 12:00 PM, 2:00 PM, and 4:00 PM achieved optimal performance: MSE 5.248, RMSE 2.291, MAE 1.694, and R2 0.823. For predicting 24-hour average IOP, the RFR model using IOP values at 10:00 AM, 12:00 PM, 4:00 PM, and 6:00 PM performed best: MSE 1.374, RMSE 1.172, MAE 0.869, and R2 0.918. The study developed machine learning models that predict 24-hour peak and average IOP. Specific time point combinations and the RFR algorithm were identified, which improved the accuracy of predicting 24-hour peak and average intraocular pressure. These findings provide the potential for more effective management and treatment strategies for glaucoma patients.

Comparing 24-hour IOP fluctuation slope curve between newly diagnosed ocular hypertension and primary open-angle glaucoma

ObjectiveTo compare the 24-hour intraocular pressure (IOP) fluctuation slope curve between newly diagnosed patients with ocular hypertension (OHT) and primary open-angle glaucoma (POAG).Methods and analysisNewly diagnosed and untreated OHT and...

24-hour intraocular pressure monitoring: past, present, and future

24-hour intraocular pressure monitoring: past, present, and future

Continuous 24-hour intraocular pressure monitoring in normal Chinese adults using a novel contact lens sensor system

AimsTo investigate the physiological nyctohemeral intraocular pressure (IOP) rhythms of normal Chinese adults using a novel contact lens sensor system (CLS) that can output IOP in millimetres of mercury (mm...

A new analysis method for 24-hour intraocular pressure data

The study aimed to introduce a new analysis method of 24-hour intraocular pressure (IOP) and to propose the concept of overall IOP. Data of 24-hour IOP of a patient with a confirmed diagnosis of normal tension glaucoma was selected. Based on the present indexes including peak IOP, trough IOP, maximum difference, and mean IOP, new indexes were proposed, which included main IOP, duration of main IOP, and rate of IOP increase. A radar chart was drawn, and overall IOP was calculated. Overall IOP value = IOP distribution (sum of IOP value multiplied by the corresponding duration) × IOP fluctuation (standard deviation) × rate of IOP increase/100. By comparing two series of IOP data, the advantages of the new IOP indexes were demonstrated. The introduction of the concept of overall IOP expands the description of IOP from a single static state to a comprehensive dynamic state, which enables us to analyze the results of 24-hour IOP monitoring more thoroughly. (Chin J Ophthalmol, 2021, 57: 228-231).

Strategies for monitoring 24-hour intraocular pressure curve: 41 cases of prospective clinical study

To investigate accuracy of the currently used strategies for intraocular pressure measurements for reflecting actual 24-hour intraocular pressure fluctuations. From September, 2018 to January, 2019, the patients with a suspected diagnosis of primary open angle glaucoma at our hospital were prospectively enrolled to receive 24-hour intraocular pressure monitoring using a Goldmann tonometer. With the intraocular pressure measurements at 0:00, 2:00, 5:00, 7:00, 8:00, 10:00, 11:00, 14:00, 16:00, 18:00, 20:00, and 22:00 as the gold standard (strategy 1), we compared the measurements taken at 5:00, 7:00, 10:00, 14:00, 18:00, and 22:00 (strategy 2) and at 8:00, 11:00, 14:00, and 16:00 (strategy 3) for their accuracy in reflecting 24-h intraocular pressure fluctuations. A total of 41 patients (82 eyes) were enrolled in this study. The peak intraocular pressures measured using the 3 strategies were 21.09±4.15 mmHg, 20.54±4.10 mmHg, and 19.91±4.38 mmHg, respectively, showing significant differences among them (P < 0.05). The trough intraocular pressures measured by the 3 strategies were also significantly different (13.93±3.38 mmHg, 14.63±3.49 mmHg, and 15.46±3.63 mmHg, respectively; P < 0.05). The co-occurrence of the peak intraocular pressure was 74.39% between strategies 1 and 2 and 43.90% between strategies 1 and 3. The sensitivity of strategies 2 and 3 for detecting 24-h intraocular pressure fluctuations was 55.56% and 36.11%, respectively. For suspected cases of glaucoma, intraocular pressure measurements at 4 and 6 time points of a day can not precisely reflect the actual range of intraocular pressure fluctuations, and may lead to a missed diagnosis of glaucoma.

24-hour Intraocular pressure monitoring: the way ahead

Aim: Large diurnal intraocular pressure (IOP) fluctuation is a single most independent risk factor for glaucoma progression besides raised IOP. The major limitation of Goldman applanation tonometer (GAT) is its inability to measure night IOP without disturbing the patient's sleep. We discussed the methods available for the 24-hour IOP monitoring and its relevance in glaucoma. Methods: A PUBMED search was performed using the 24 Hour tonometry, newer tonometry devices, contact lens sensors, as keywords and all relevant articles were studied. Results and Conclusion: A number of methods are available for the 24 hour IOP monitoring. These devices allow home monitoring of IOP without affecting the daily routine. These devices, like Rebound tonometry, Contact lens sensor (CLS), etc., were briefly discussed. Triggerfish is one CLS device that has the capability to measure IOP without affecting the patient's sleep. Besides being safe and easily tolerable, it has shown reproducible results with other tonometry methods. Triggerfish has also been proven the device of choice in measuring IOP in different glaucoma subtypes and determining the efficacy of treatment in them, the only challenge being that it presently provides data on relative IOP rather than absolute IOP. With future research, triggerfish CLS can become an important device to measure the 24 hour IOP values especially in patients whose office measured IOPs seemingly fit in patient's target range but still the patients' disease shows glaucomatous progression. The utility of this device in relation to progressive vision loss is a matter of future study. Abbreviations: CCT = Central Corneal Thickness; CLS = Contact lens sensor; GAT = Goldmann Applanation Tonometer; IOP = Intraocular Pressure; NTG = Normal Tension Glaucoma; PACG = Primary angle closure glaucoma; POAG = Primary open angle glaucoma; VAS = Visual Analogue Score.

Role of 24-Hour Intraocular Pressure Monitoring in Glaucoma Management.

Glaucoma is the leading cause of irreversible blindness worldwide and the prevalence is on the rising trend. Intraocular pressure (IOP) reduction is the mainstay of treatment. The current practice of IOP monitoring is based on spot measurements during clinic visits during office hours. However, there are up to 50% of glaucoma patients who had normal initial IOP, while some treated patients continued to have progressive glaucomatous optic nerve damage even with a low IOP. Recent studies have shown that the IOP of glaucoma patients fluctuated during the day with different patterns, and some of them had peak IOP outside office hours. These findings provided us with new insights on the role of 24-hour IOP monitoring in managing normal tension glaucoma and patients with progressive deterioration despite apparently well-controlled IOP. Nevertheless, results to date are rather inconsistent, and there is no consensus yet. In this review, we briefly highlighted the current modalities of 24-hour IOP monitoring and summarized the characteristic 24-hour IOP pattern and the clinical relevance of IOP parameters in predicting glaucomatous progression in different glaucoma subtypes. We also discussed the therapeutic efficacy of current glaucoma treatment modalities with respect to the mentioned 24-hour IOP profiles, so as to strengthen the role of 24-hour IOP monitoring in identifying and stratifying the risks of progression in glaucoma patients, as well as optimizing treatments according to their IOP profiles.

Evaluation of influence of non-office hours diurnal variation of intraocular pressure in management of glaucoma

Aim and Objectives: This article attempts to elucidate the role of round the clock IOP control and its relevance to current glaucoma practice. Materials and Methods: A prospective observational study was carried out on 50 patients of POAG or CACG on medical management whose intraocular pressures were found to be controlled by daytime office hours IOP estimation. The diurnal IOP readings obtained with Clarkes Hand held Perkins applanation tonometer and Reicherts Tonopen at 7am, 10am, 1pm, 4pm, 7pm, 10pm, 1am and 4am. Comparison of office hours IOP, extended office hours DVT and 24 hours IOP was done. Results: Fifty patients were enrolled (mean age: 53.88 ± 8.42 years) in the study. The mean office hours IOP for both eyes was significantly less (16.31±2.46) than extended office hours (17.18±2.50) and 24 hours DVT (17.49 ±2.45). There was significant difference in IOP fluctuation in office (3.72±2.14) versus extended office hours (9.26±3.11) and 24 hours DVT (10.28±2.76). The mean office hours peak IOP was significantly lower than that of extended office hours and 24 hours DVT. Conclusion: 24-hour IOP monitoring can reveal higher peaks and wider fluctuation of IOP than those found during typical office hours, it suggests a greater role for IOP-related risk for glaucoma progression. Thus may justify a more aggressive IOP-lowering treatment strategy. Keywords: Chronic angle closure glaucoma (CACG), Clarkes hand held perkins applanation tonometer, Intraocular pressure (IOP), glaucoma, Primary open angle glaucoma (POAG), Reicherts tonopen.

The 24-hour intraocular pressure control by tafluprost/timolol fixed combination after switching from the concomitant use of tafluprost and timolol gel-forming solution, in patients with primary open-angle glaucoma.

ObjectiveThe aim of this study was to evaluate the 24-hour intraocular pressure (IOP)-control effect of the tafluprost/timolol fixed combination (TAF/TIM-FC) in patients with primary open-angle glaucoma after they switched from the concomitant use of tafluprost and timolol gel-forming solution.Patients and methodsTwenty patients with primary open-angle glaucoma (12 male and 8 female; mean ± SD age, 57.0±7.1 years) were included in this study. The patients were treated for 8 weeks with the concomitant administration of tafluprost and timolol gel-forming solution (evening dosing). At the end of this period, the patients underwent 24-hour IOP monitoring (measured at 21:00, 01:00, 05:00, 09:00, 13:00 and 17:00). IOP was measured with Goldmann applanation tonometer (GAT) and Icare PRO at sitting position at all timepoints and additionally, at supine position with Icare PRO tonometer at 01:00 and 05:00. The patients were then all switched to TAF/TIM-FC treatment (evening dosing). After 8 weeks, the 24-hour IOP monitoring was repeated.ResultsNineteen patients completed the study. The mean 24-hour IOPs in the concomitant and TAF/TIM-FC phases were 13.8±2.7 vs 13.3±2.8 mmHg (P=0.0033) with the GAT in the sitting position and 13.96±2.56 vs 13.48±2.56 mmHg (P=0.0120) with the Icare PRO in habitual positions. In comparison with the concomitant phase, significantly lower IOP was observed for the TAF/TIM-FC phase at 21:00 and 01:00 with the GAT and at 01:00 with the Icare PRO. In addition, the maximum IOP and fluctuations in IOP in habitual positions were lower for the TAF/TIM-FC phase than for the concomitant phase.ConclusionTAF/TIM-FC showed a stable 24-hour IOP-lowering effect and was equally or more effective than the concomitant use of tafluprost and timolol gel, both when sitting and when in habitual positions.

Exploration on the 24 hour intraocular pressure fluctuation in glaucoma patients

Intraocular pressure is the most important and most easily controlled clinical parameters of glaucoma. It has a fluctuation and circadian rhythm. The 24 hours intraocular pressure measurement can better reflect the changes of intraocular pressure. It is clear that peak IOP is an independent risk factor for the progression of glaucoma, but the effect of IOP on glaucoma progression is worth exploring. This article focuses on whether IOP fluctuation is an independent risk factor for glaucoma progression, how to obtain the 24-hour intraocular pressure curve, the future direction of 24-hour intraocular pressure monitoring and other issues in order to cause clinical concern. (Chin J Ophthalmol, 2017, 53: 85-88).

Detecting IOP Fluctuations in Glaucoma Patients.

Lowering intraocular pressure (IOP) remains the guiding principle of glaucoma management. Although IOP is the only treatable risk factor, its 24-hour behavior is poorly understood. Current glaucoma management usually relies on single IOP measurements during clinic hours, even though IOP is a dynamic parameter with rhythms dependent on individual patients. It has further been shown that most glaucoma patients have their highest IOP measurements outside clinic hours. The fact that these IOP peaks go largely undetected may explain why certain patients progress in their disease despite treatment. Nevertheless, single IOP measurements have determined all major clinical guidelines regarding glaucoma treatment. Other potentially informative parameters, such as fluctuations in IOP and peak IOP, have been neglected, and effects of IOP-lowering interventions on such measures are largely unknown. Continuous 24-hour IOP monitoring has been an interest for more than 50 years, but only recent technological advances have provided clinicians with a device for such an endeavor. This review discusses current uses and shortcomings of current measurement techniques, and provides an overview on current and future methods for 24-hour IOP assessment. It may be possible to incorporate continuous IOP monitoring into clinical practice, potentially to reduce glaucoma-related vision loss.

The Application of a Contact Lens Sensor in Detecting 24-Hour Intraocular Pressure-Related Patterns.

Glaucoma is one of the leading causes of blindness worldwide. Recent studies suggest that intraocular pressure (IOP) fluctuations, peaks, and rhythm are important factors in disease advancement. Yet, current glaucoma management remains hinged on single IOP measurements during clinic hours. To overcome this limitation, 24-hour IOP monitoring devices have been employed and include self-tonometry, permanent IOP, and temporary IOP monitoring. This review discusses each IOP measuring strategy and focuses on the recently FDA-approved contact lens sensor (CLS). The CLS records IOP-related ocular patterns for 24 hours continuously. Using the CLS, IOP-related parameters have been found to be associated with the rate of visual field progression in primary open-angle glaucoma, disease progression in primary angle-closure glaucoma, and various clinical variables in ocular hypertension. The CLS has been used to quantify blink rate and limbal strain and measure the circadian rhythm in a variety of disease states including normal-tension glaucoma and thyroid eye disease. The effects of various IOP-lowering interventions were also characterized using the CLS. CLS provides a unique, safe, and well-tolerated way to study IOP-related patterns in a wide range of disease states. IOP-related patterns may help identify patients most at risk for disease progression and assist with the development of tailored treatments.

Personalizing Intraocular Pressure: Target Intraocular Pressure in the Setting of 24-Hour Intraocular Pressure Monitoring.

Determining target intraocular pressure (IOP) in glaucoma patients is multifaceted, requiring attention to many different factors such as glaucoma type, severity of disease, age, race, family history, corneal thickness and hysteresis, and initial IOP. Even with all these variables accounted for, there are still patients who have progression of the disease despite achieving target IOP. Intraocular pressure variability has been identified as a potential independent risk factor for glaucoma progression but is currently difficult to quantify in individual patients. New technologies enabling measurement of both diurnal and nocturnal IOP may necessitate modifying our concept of target pressure.

Distribution of peak intraocular pressure in 24-hour and correlation between peak nocturnal intraocular pressure with diurnal intraocular pressure level in primary open angle glaucoma patients

To study the distribution of peak intraocular pressure (IOP) in 24-hour in untreated primary open angle glaucoma (POAG) patients, and to explore the correlation between nocturnal peak IOP and office hour or diurnal IOP level. A Cross-sectional study.One hundred and twenty-one untreated POAG patients (121 eyes), including 78 normal tension patients (78 eyes) and 43 hyper-tension patients (43 eyes), were enrolled in this study. All the patients underwent 24-hour IOP monitoring with non-contact tonometer. The distribution of peak IOP in 24-hour and the correlation between nocturnal peak IOP and office hour or diurnal mean and peak IOP were evaluated. Categorical variables were described as frequency and constituent ratio, and analyzed by chi-square test. Continuous variables were described as mean, standard deviation, range, and analyzed by independent samples t test, pearson correlation test and linear regression. In all glaucoma patients, peak IOP occurred mainly from 8:00 to 10:00 and 8:00 to 10:00.In normal tension group, peak IOP appeared mainly from 8:00 to 10:00 and from 0:00 to 6:00, the highest frequency showed at 8:00 (17 eyes 18.48%).In hyper-tension group, the probability of IOP reaching peak was more in night time, mainly from 0:00 to 6:00, the highest frequency showed at 2:00 (10 eyes 21.28%). If only the peak IOP during office hours or diurnal hours were considered, then only 32.55% (14/43) and 44.19% (19/43) patients could be correctly diagnosed. The remaining patients would be missed because of low IOP and/or mild structure and/or functional damages. There were good linear correlations between office hours or diurnal peak and mean IOP and nocturnal peak IOP in glaucoma patients. More than 50% peak IOP occurred out of office hour in POAG patients. There is a good correlation between peak nocturnal IOP and office hour or diurnal IOP level.

Fundamentals and Advances in Tonometry.

According to the World Health Organization, glaucoma is the leading cause of irreversible blindness worldwide. Although intraocular pressure (IOP) is not considered any more to be a defining feature of the disease, its lowering remains the only treatment option for glaucoma. Therefore, accurate and precise measurement of IOP is the cornerstone of glaucoma. Intraocular pressure is a highly dynamic physiological parameter with individual circadian rhythms. The main limitation of current tonometry methods remains the static and mostly office-based nature of their measurements. This review provides a brief historical overview on tonometry and discusses current tonometry instruments. In recent years, approaches to 24-hour IOP monitoring have been introduced, and there is hope that they may become part of routine clinical management in the future.

Evaluation of Continuous 24-Hour Intraocular Pressure Monitoring for Assessment of Prostaglandin-induced Pressure Reduction in Glaucoma

To evaluate 24-hour continuous intraocular pressure (IOP) monitoring with a telemetric contact lens sensor (CLS) to detect prostaglandin-induced IOP reduction. In this prospective interventional study 9 ocular hypertensive and primary open-angle glaucoma patients were washed out from IOP-lowering medication for 6 weeks. One study eye per patient underwent 3 baseline 24-hour measurement curves 4 days apart: 2 curves with Sensimed Triggerfish CLS and 1 curve with Goldmann applanation tonometry (GAT). Then the patients received travoprost monotherapy for 3 months. The 24-hour CLS and GAT curves were repeated on the study eyes under treatment at the end of the third month. The 24-hour GAT IOP (mean±SD) decreased from 22.91±5.11 to 18.24±2.49 mm Hg (P<0.001). In contrast, the means of the 3 CLS curves showed no significant difference (152.94, 142.35, and 132.98 au, P=0.273). No difference was seen when the SD values of the 3 CLS curves were compared (133.51, 132.18, and 110.98 au, P=0.497). All CLS curves showed an increasing time trend (P≤0.001). Correlation of all 3 CLS curves of the individual eyes was high (r=0.726), but no correlation was seen between the corresponding CLS curve periods and GAT IOP values either at baseline (r=-0.223, P=0.546) or under treatment (r=0.320, P=0.402). No difference was seen between the erect/sitting (waking) and supine (sleeping) period CLS values (P>0.05). Our results suggest that the current CLS technique cannot be clinically used to monitor IOP decrease induced by topical medication in glaucoma, and has limited value in identification of transient IOP elevation periods.

24-Hour Intraocular Pressure Rhythm in Young Healthy Subjects Evaluated With Continuous Monitoring Using a Contact Lens Sensor

This study evaluates a new device that has been proposed to continuously monitor intraocular pressure (IOP) over 24 hours. To evaluate 24-hour IOP rhythm reproducibility during repeated continuous 24-hour IOP monitoring with noncontact tonometry (NCT) and a contact lens sensor (CLS) in healthy participants. Cross-sectional study of 12 young healthy volunteers at a referral center of chronobiology. Participants were housed in a sleep laboratory and underwent four 24-hour sessions of IOP measurements over a 6-month period. After initial randomized attribution, the IOP of the first eye was continuously monitored using a CLS and the IOP of the fellow eye was measured hourly using NCT. Two sessions with NCT measurements in 1 eye and CLS measurements in the fellow eye, 1 session with CLS measurements in only 1 eye, and 1 session with NCT measurements in both eyes were performed. A nonlinear least squares, dual-harmonic regression analysis was used to model the 24-hour IOP rhythm. Comparison of acrophase, bathyphase, amplitude, midline estimating statistic of rhythm, IOP values, IOP changes, and agreement were evaluated in the 3 tonometry methods. A significant nyctohemeral IOP rhythm was found in 31 of 36 sessions (86%) using NCT and in all sessions (100%) using CLS. Hourly awakening during NCT IOP measurements did not significantly change the mean phases of the 24-hour IOP pattern evaluated using CLS in the contralateral eye. Throughout the sessions, intraclass correlation coefficients of the CLS acrophase (0.6 [95% CI, 0.0 to 0.9]; P = .03), CLS bathyphase (0.7 [95% CI, 0.1 to 0.9]; P = .01), NCT amplitude (0.7 [95% CI, 0.1 to 0.9]; P = .01), and NCT midline estimating statistic of rhythm (0.9 [95% CI, 0.9 to 1.0]; P < .01) were significant. When performing NCT measurements in 1 eye and CLS measurements in the contralateral eye, the IOP change at each point normalized from the first measurement (9 am) was not symmetric individually or within the population. The CLS is an accurate and reproducible method to characterize the nyctohemeral IOP rhythm in healthy participants but does not allow for estimating the IOP value in millimeters of mercury corresponding to the relative variation of the electrical signal measured.

A Minimally Invasive Device for the Monitoring of 24-hour Intraocular Pressure Patterns

Intraocular pressure (IOP) is the only modifiable risk factor for glaucoma, and lowering of IOP remains the mainstay of glaucoma treatment. IOP is a dynamic biologic parameter, nevertheless, current glaucoma management usually relies on single IOP measurements during clinic hours. However, a majority of glaucoma patients have their high, including their highest, IOP levels outside clinic hours. These undetected IOPs may explain why certain patients have progressive disease despite treatment. The interest in continuous 24-hour IOP monitoring started over half a century ago, but only recent technologic advances have provided clinicians with a practical device for continuous IOP monitoring. In this article, we discuss innovative approaches with permanent and temporary devices for 24-hour IOP monitoring, such as a contact lens sensor. Despite being in their infancy, these devices may soon enable clinicians to use 24-hour IOP data to improve glaucoma management and reduce the glaucoma-related burden of disease.

Tolerability of 24-Hour Intraocular Pressure Monitoring of a Pressure-sensitive Contact Lens

To investigate tolerability and safety of a new diagnostic device for 24-hour intraocular pressure monitoring in healthy subjects and age-matched glaucoma patients. Twenty healthy subjects (group 1) and 20 age-matched glaucoma patients (group 2) were included in this prospective, single-center, open, observational parallel group study. The SENSIMED Triggerfish Sensor is a soft disposable contact lens embedding a telemetry chip and strain gauge sensor for continuous intraocular pressure monitoring. The Sensor was placed in 1 eye for 24 hours. Tolerability was evaluated using a visual analog scale (range, 0 to 100; 0=no discomfort; 100=very severe discomfort). Safety parameters included best corrected visual acuity, pachymetry, epithelial defects, conjunctival erythema, and corneal topography. Mean age was 61.7 years in group 1 and 65.0 years in group 2. Nineteen healthy subjects and 19 glaucoma patients (95%) completed the 24-hour wearing period. Early discontinuation resulted from pain (n=1) or inappropriate fitting of the sensor due to steep corneal radii (n=1). Mean tolerability was 21.8 in group 1 (range, 7 to 67) and 26.8 in group 2 (range, 0 to 71). Corneal epithelial staining (Modified Oxford scale, grade 0 to 4) changed from 0.4 (group 1) and 1.0 (group 2) at baseline to 1.8 (group 1) and 2.8 (group 2) after monitoring. No statistically significant differences could be detected between both groups. This new pressure-sensitive contact lens is tolerable and safe over a 24-hour wearing period in healthy subjects and glaucoma patients. Both normals and glaucoma patients had a similar safety and tolerability profile.