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

Polymer-Based Self-Assembled Drug Delivery Systems for Glaucoma Treatment: Design Strategies and Recent Advances

Glaucoma has become the world's leading cause of irreversible blindness, and one of its main characteristics is high intraocular pressure. Currently, the non-surgical drug treatment scheme to reduce intraocular pressure is a priority method for glaucoma treatment. However, the complex and special structure of the eye poses significant challenges to the treatment effect and safety adherence of this drug treatment approach. To address these challenges, the application of polymer-based self-assembled drug delivery systems in glaucoma treatment has emerged. This review focuses on the utilization of polymer-based self-assembled structures or materials as important functional and intelligent carriers for drug delivery in glaucoma treatment. Various drug delivery systems, such as eye drops, hydrogels, and contact lenses, are discussed. Additionally, the review primarily summarizes the design strategies and methods used to enhance the treatment effect and safety compliance of these polymer-based drug delivery systems. Finally, the discussion delves into the new challenges and prospects of employing polymer-based self-assembled drug delivery systems for the treatment of glaucoma.

The role of optical coherence tomography angiography in moderate and advanced primary open-angle glaucoma

PURPOSE

To evaluate the relationship between structure and function in moderate and advanced primary open-angle glaucoma (POAG) and to determine the accuracy of structure and vasculature for discriminating moderate from advanced POAG.

METHODS

In this cross-sectional study, 25 eyes with moderate and 40 eyes with advanced POAG were enrolled. All eyes underwent measurement of the thickness of circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (GCC), and optical coherence tomography angiography (OCTA) of the optic nerve head (ONH) and macula. Visual field (VF) was evaluated by Swedish interactive threshold algorithm and 24-2 and 10-2 patterns. The correlation between structure and vasculature and the mean deviation (MD) of the VFs was evaluated by a partial correlation coefficient. The area under the receiver operating characteristic curve (AUC) was applied for assessing the power of variables for discrimination moderate from advanced POAG.

RESULTS

Including all eyes, whole image vessel density (wiVD) of the ONH area, and vessel density (VD) in the inferior quadrant of perifovea were the parameters with significant correlation with the mean deviation (MD) of the VF 24-2 in OCTA of the ONH and macula (r = .649 and .397; p < .05). The greatest AUCs for discriminating moderate and advanced POAG belonged to VD of the inferior hemifield of ONH area (.886; 95% CI (.805, .967)), and VD in the inferior quadrant of perifovea (.833; 95% CI (.736, .930)) without statistically significant difference (.886 Versus .833; p = .601).

CONCLUSION

Among vascular parameters of the ONH area, wiVD had the strongest correlation with the MD of the VF 24-2 while VD of the inferior hemifield of the ONH area had the greatest AUC for discriminating moderate and advanced POAG. Vessel density in the inferior quadrant of perifovea had a significant correlation with the MD of VF 24-2 and also the greatest AUC for discriminating moderate and advanced POAG.

Deployment of the Water Drinking Test and iCare HOME Phasing for Intraocular Pressure Profiling in Glaucoma Evaluation

SIGNIFICANCE

Intraocular pressure (IOP) profiling is an important component of the glaucoma examination. Two techniques for profiling are the water drinking test (WDT) and iCare HOME phasing, but the correlations between techniques and their ease of deployment have not been studied. These questions are important in determining suitability for clinical deployment.

PURPOSE

This study aimed to compare the IOP results of the WDT and iCare HOME phasing in patients with suspected or newly diagnosed glaucoma.

METHODS

Ninety-eight consecutive patients attending a glaucoma clinic underwent IOP profiling using both techniques. For the WDT, patients ingested 10 mL/kg body weight of water after a baseline applanation IOP measurement and then underwent serial IOP measurements approximately every 15 minutes, ceasing after 30 minutes of consecutive measurements within 3 mmHg of baseline. Patients successfully certified for self-administration of the iCare HOME were loaned the instrument for 1 week and instructed to take four measurements per day.

RESULTS

Twenty-seven patients (28%) successfully obtained four measurements per day using iCare HOME, and 96 patients (98%) were able to complete the WDT. Intraocular pressure profiles showed no difference between the time for peak IOP and across nearly all IOP parameters obtained from profiling except for the standard deviation of IOP measurements obtained using the iCare HOME (P = .005). There were moderate correlations between peak IOPs obtained using each technique (r = 0.67, P = .001, right eye; r = 0.66, P = .002, left eye) but no correlation between the daily range (iCare HOME) or peak-trough difference (WDT; r = 0.21, P = .28, right eye; r = 0.27, P = .02, left eye). Bland-Altman analysis returned similar results for peak and range.

CONCLUSIONS

Intraocular pressure profiling using both techniques can reveal the peak IOP, and these measurements are strongly correlated. Most patients were unable to complete the iCare HOME according to the manufacturer's recommendations. Clinicians should select the most appropriate technique for each patient.

A comparison of postural and diurnal variations in intraocular pressure using the iCare rebound tonometer and Perkins applanation tonometer in admitted adults in Kenya

Background: Elevated intraocular pressure (IOP) remained the most important known risk factor for glaucoma.Aim: To compare the postural and diurnal IOP variations using the iCare rebound tonometer (RT) and Perkins applanation tonometer (PAT).Setting: Kakamega County Hospital, Kenya.Methods: Elevated intraocular pressure measurements were taken by two (masked) examiners with two devices in the morning (06:00–09:00), midday (12:00–15:00) and evening (18:00–21:00), in the sitting followed by supine positions in one randomly selected eye of 24 oculo-visual healthy hospital-admitted patients. Effects of the time of the day and position of the body within and between devices were analysed with the Statistical Package for Social Sciences.Results: The mean IOP measured by the RT ranged from 6 mmHg to 24 millimetres of mercury (mmHg) in the sitting position and from 10 mmHg to 26 mmHg in the supine position. The mean IOP measured using PAT ranged from 6 mmHg to 21 mmHg in the sitting position and from 8 mmHg to 24 mmHg in the supine position. The IOP measured by both devices significantly varied with position (p 0.05). Perkins applanation tonometer on average gave a significantly higher IOP (1.7 mmHg [p = 0.003] and 1.3 mmHg [p = 0.034]) at 06:00 compared to that at 12:00 and 18:00, respectively. The IOP readings with the RT were on average 2.2 mmHg and 3.0 mmHg higher at 06:00 compared to that at 12:00 and 18:00, respectively (p 0.0005).Conclusion: Significant reductions were observed in postural and diurnal IOPs in the sitting positions and in the afternoon, respectively. Diurnal IOP variations were slightly higher when measured by RT compared to when measured by PAT.

Corneal Biomechanical Assessment with Ultra-High-Speed Scheimpflug Imaging During Non-Contact Tonometry: A Prospective Review

BACKGROUND

In recent years, increasing interest has arisen in the application of data from corneal biomechanics in many areas of ophthalmology, particularly to assist in the detection of early corneal ectasia or ectasia susceptibility, to predict corneal response to surgical or therapeutic interventions and in glaucoma management. Technology has evolved and, recently, the Scheimpflug principle was associated with a non-contact air-puff tonometer, allowing a thorough analysis of corneal biomechanics and a biomechanically corrected intraocular pressure assessment, opening up new perspectives both in ophthalmology and in other medical areas. Data from corneal biomechanics assessment are being integrated in artificial intelligence models in order to increase its value in clinical practice.

OBJECTIVE

To review the state of the art in the field of corneal biomechanics assessment with special emphasis to the technology based on ultra-high-speed Scheimpflug imaging during non-contact tonometry.

SUMMARY

A meticulous literature review was performed until the present day. We used 136 published manuscripts as our references. Both information from healthy individuals and descriptions of possible associations with systemic diseases are described. Additionally, it exposed information regarding several fields of ocular pathology, from cornea and ocular surface through areas of refractive surgery and glaucoma until vascular and structural diseases of the chorioretinal unit.

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.