Intraocular Pressure Fluctuation Research Articles

Nyctohemeral effects of topical beta-adrenoceptor blocking agents measured with an intraocular telemetry sensor

ObjectiveTo evaluate nyctohemeral effects of topical beta-adrenoceptor blocking agents and their fixed combinations on intraocular pressure (IOP) in patients with primary open-angle glaucoma implanted with an ocular telemetry sensor.Methods22 patients...

Intraocular Pressure Fluctuation as Assessed by Water Drinking Test Following iStent inject Implantation in Open Angle Glaucoma Patients.

Introduction This study investigated the intraocular pressure (IOP) fluctuation as assessed by the water drinking test (WDT) in open-angle glaucoma (OAG) patients after combined cataract surgery with iStent implantation. Methods This was a prospective non-randomized comparative study. Eyes with OAG and cataracts that were planned for either combined phacoemulsification and iStent implantation (iStent+CS) or phacoemulsification alone (CS) were recruited. The iStent inject (Model G2-M-IS) or iStent injectW (Model G2-W) trabecular micro-bypass stent (Glaukos Corporation, San Clemente, CA, USA) was implanted in the iStent+CS group. Water drinking test (WDT) was performed before and 3 months after surgery. WDT-IOP parameters including peak IOP, IOP fluctuation, and area under curve (AUC) were compared between the two groups. Results There were 20 eyes in the iStent+CS group and 16 eyes in the CS group. Both groups had similar pre-operative baseline IOP (15.6 ± 3.7 mmHg vs 15.8 ± 1.8 mmHg in the iStent+CS and CS group, respectively, p = 0.883). The iStent+CS group experienced greater numerical reduction in peak IOP (2.6 ± 1.9 mmHg vs 1.9 ± 2.4 mmHg; p = 0.355), IOP fluctuation (1.7 ± 2.2 mmHg vs 0.8 ± 2.5 mmHg; p = 0.289), and AUC (54.8 ± 103.6 mmHg x minute vs 25.3 ± 79.0 mmHg x minute; p = 0.355) than the CS group. There was more reduction in the number of anti-glaucoma medications in the iStent+CS group (1.4 ± 1.2) than the CS group (0.3 ± 0.9; p = 0.005). Conclusion Both combined phacoemulsification with iStent inject implantation and phacoemulsification alone reduced peak IOP, IOP fluctuation, and AUC, and none of these parameters showed statistically significant difference. Greater reduction in anti-glaucoma medications was seen in the combined group.

Factors Associated with Retinal Microvasculature Dropout Induced by Elevation of Intraocular Pressure in Primary Open-Angle Glaucoma.

To investigate the risk factors related to decrease in vessel density (VD) observed in primary open-angle glaucoma (POAG), due to acute increase in intraocular pressure (IOP) by an ophthalmodynamometer (OPD). This cross-sectional study involved 42 eyes of participants (22 Controls and 20 POAG patients) that underwent optical coherence tomography angiography (OCT-A) to assess VD in the peripapillary region in three examination sets: primary gaze position (1), 25-degree adduction (2) and 25-degree adduction with OPD compression (3). Individual relationships between IOP levels and changes in the superficial complex VD were evaluated after image processing and exclusion of large retinal vessels. Multivariable regression analysis was used to verify factors associated with differences in VD induced by IOP elevation. A significant increase in IOP was induced by OPD compression during adduction (mean ± SD, Control: + 13.8 ± 2.8; POAG: + 13.4 ± 2.1mmHg). Only during IOP elevation (set 3), a significant VD decrease was observed both in POAG eyes (p = 0.008) and controls (p = 0.022). Baseline IOP (p = 0.022), maximum IOP (p = 0.003), and scleral rigidity (p = 0.029) were significantly associated with VD decreases in eyes with POAG. No changes were observed in VD during adduction gaze exclusively. Acute IOP elevation induced with OPD, but not adduction gaze, decreased peripapillary VD measured with OCT-A imaging. IOP levels and scleral rigidity significantly affected VD reduction in POAG patients. Thus, high scleral rigidity may decrease the ability of the globe to dampen the well-known effects of IOP fluctuation on glaucoma onset and progression. What is known Decrease vascular density in the peripapillary retina was associated with POAG, but factors related to the vascular response to elevated IOP are unexplored. What is new OCT-A quantification shows decreases in vascular density of the superficial layers of the peripapillary retina during an acute elevation in IOP. High IOP levels and scleral rigidity significantly affected vascular density reduction in POAG patients.

Serum lipid and lipoprotein profiles and their association with intraocular pressure in primary open-angle glaucoma: an observational cross-sectional study in the Chinese population

BackgroundGlaucoma is a leading cause of vision impairment and permanent blindness. Primary open-angle glaucoma (POAG) is a prominent type of primary glaucoma; however, its cause is difficult to determine. This study aimed to analyze the serum lipid profile of Chinese POAG patients and assess its correlation with intraocular pressure (IOP).MethodsThe study included 1,139, 1,248, and 356 Chinese individuals with POAG, primary angle closure glaucoma (PACG), and controls, respectively. Peripheral whole blood samples were collected at the time of diagnosis. Enzymatic colorimetry was used to determine serum levels of different lipids: high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides, cholesterol, and very low-density lipoproteins (VLDL). Additionally, immunoturbidimetry was used to quantify serum levels of apolipoproteins A (APOA), B (APOB), E (APOE), and lipoprotein A [Lp(a)], while intraocular pressure (IOP) was measured in all patients with POAG.ResultsAfter adjusting for age and sex, patients with POAG exhibited elevated serum levels of VLDL, APOA, and APOE but mitigated cholesterol levels compared with the control participants. Significantly lower serum triglyceride, VLDL, and Lp(a) levels were found in patients with PACG than in control participants. Serum cholesterol (P = 0.019; β = -0.75, 95% confidence interval [CI]: -1.38 – -0.12) and HDL levels (P < 0.001; β = -2.91, 95% CI: -4.58 – -1.25) were inversely linked to IOP in patients with POAG, after adjusting for age, sex, and ocular metrics. In addition, serum Lp(a) levels were correlated with the average IOP (P = 0.023; β = -0.0039, 95% CI: -0.0073 – -0.006) and night peak (P = 0.027; β = -0.0061, 95% CI: -0.0113 – -0.0008) in patients with POAG.ConclusionsSignificantly different serum lipid and lipoprotein profiles were observed in POAG and PACG patients. This study highlighted the differences in serum lipid and lipoprotein levels among Chinese POAG patients and their relationship with IOP and IOP fluctuation. Serum lipid and lipoprotein profiles should be considered while evaluating glaucoma risk.

Analysis of factors affecting the progression of visual field defects in patients with myopia and primary open-angle glaucoma

Objective: To investigate the factors affecting the progression of visual field defects in patients with myopia and primary open-angle glaucoma (POAG), and to clarify whether the factors vary in patients with different degrees of myopia. Method: An ambispective cohort study was conducted among patients diagnosed with myopia and POAG from the glaucoma outpatient department at the Zhongshan Ophthalmic Center of Sun Yat-sen University between January 2006 and January 2024. Based on the criteria of functional visual field progression, patients were divided into the progression group and non-progression group, and further divided into the low to moderate myopia subgroup and high myopia subgroup according to the degree of myopia. The patient age, gender, type of glaucoma (high tension glaucoma and normal tension glaucoma), spherical equivalent refraction, best corrected visual acuity (BCVA, recorded as the logarithm of the minimum angle of resolution), intraocular pressure (IOP), central corneal thickness, baseline visual field, history of ophthalmic surgery (corneal refractive surgery and glaucoma surgery), and number of anti-glaucoma medications were summarized. The generalized estimation equation was used for comparison between groups, and the Cox proportional hazards model was used to analyze the factors affecting the progression of visual field defects. Results: A total of 182 eyes from 106 patients were included in this study. There were 57 eyes in the progression group and 125 eyes in the non-progression group. Compared with the non-progression group, the progression group had the older age [43 (29, 53) years old], worse BCVA [0.05 (0.00, 0.17)], greater IOP fluctuation [1.8 (1.3, 2.9)mmHg(1 mmHg=0.133 kPa)], more common baseline central defects [52.6%(30/57)], higher visual field pattern standard deviations [8.92 (5.32, 12.00)dB], lower visual field index [77% (67%, 88%)], and more anti-glaucoma medications [35.1% (20/57) patients used three medications] (all P<0.05). The Cox proportional hazards models showed that the baseline moderate visual field defects [hazard ratio (HR)=2.33, 95% confidence interval (CI): 1.25 to 4.36, P=0.008], baseline central defects (HR=2.09, 95%CI: 1.11 to 3.93, P=0.022), older age (Model A, HR=1.03, 95%CI: 1.00 to 1.05, P=0.017; Model B, HR=1.02, 95%CI: 1.00 to 1.05, P=0.019), and greater IOP fluctuation (Model A, HR=1.54, 95%CI: 1.32 to 1.81, P<0.001; Model B, HR=1.49, 95%CI: 1.26 to 1.75, P<0.001) were risk factors for visual field progression. In the low to moderate myopia subgroup, the increased risk of progression was associated with baseline central defects (HR=5.74, 95%CI: 1.72 to 19.20, P=0.005), worse BCVA (Model A, HR=15.80, 95%CI: 2.07 to 121.00, P=0.008; Model B, HR=12.50, 95%CI: 2.65 to 58.70, P=0.001), and older age (Model A, HR=1.05, 95%CI: 1.02 to 1.08, P=0.002; Model B, HR=1.07, 95%CI: 1.03 to 1.11, P<0.001). In the high myopia subgroup, the increased risk of progression was associated with baseline moderate visual field defects (HR=2.35, 95%CI: 1.12 to 4.92, P=0.024) and greater IOP fluctuation (Model A, HR=1.50, 95%CI: 1.24 to 1.82, P<0.001; Model B, HR=1.52, 95%CI: 1.26 to 1.83, P<0.001). Conclusions: Age, IOP fluctuation, baseline moderate visual field defects, and baseline central defects were the factors affecting the progression of visual field defects in patients with myopia and POAG. There were differences in the influencing factors of visual field progression in patients with different degrees of myopia.

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...

Comparative evaluation of modified diurnal tension curve with water drinking test among glaucoma suspects at University of Port Harcourt Teaching Hospital, Rivers State, Nigeria

Objective: The objective of the study was to assess the correlation of intraocular pressure (IOP) peaks and fluctuation obtained using a modified diurnal tension curve (mDTC) and water drinking test (WDT) and to investigate the relevance of routine use of WDT in glaucoma suspects at University of Port Harcourt Teaching Hospital, Port Harcourt, Rivers State Nigeria. Materials and Methods: Glaucoma suspects were enrolled in this prospective comparative study. A total of 138 participants were recruited. All participants were subjected to two hourly IOP checks for 8 h (mDTC starting from 8:00 am). The WDT was done the following day, starting at 8:00 am. There was a 2-h water fast before the commencement of the WDT and IOP was measured every 15 min for 1 h after ingestion of 1 L of water. Results: Out of the 138 glaucoma suspects recruited for the study, 57 were male and 81 females, with a mean age of 37.8 ± 11.7 years. The mean peak IOP measured during mDTC (19.0 ± 3.5 mmHg) was statistically different from that measured during WDT (20.9 ± 4.4 mmHg; P &lt; 0.001). The mean IOP fluctuation measured during the mDTC (5.6 ± 1.9 mmHg) was also statistically different from that measured by WDT (6.9 ± 2.7 mmHg) (P &lt; 0.001). The peak IOP measured during mDTC showed a strong correlation with peak IOP during WDT (r = 0.840); however, there was moderate agreement between the two peaks (k = 0.408). The IOP peaks of mDTC and WDT showed excellent strength of association (Cronbach’s alpha = 0.901) and poor strength of association for the fluctuation in IOP (Cronbach’s alpha = 0.556). Conclusion: The WDT can provide an easier, nonexpensive, and less time-consuming method of peak IOP determination, which will aid in the timely management of glaucoma patients.

A Novel Implantable Piezoresistive Microsensor for Intraocular Pressure Measurement.

Glaucoma is the world's second-leading irreversible eye disease causing blindness. Although the pathogenesis of glaucoma is not particularly well understood, high intraocular pressure (IOP) is widely recognized as a significant risk factor. In clinical practice, various devices have been used to measure IOP, but most of them cannot provide continuous measurements for a long time. To meet the needs of glaucoma patients who experience frequent fluctuations in the IOP and require constant monitoring, we fabricated an implantable piezoresistive IOP sensor based on microfluidic technology. The sensor has a sensitivity of 0.00257 Ω/mbar and demonstrates excellent linearity, stability, and repeatability. According to the calibration data, the average measurement error is ±0.5 mbar. We implanted it into the vitreous of a rabbit and successfully detected its IOP fluctuations. The sensor is simple in design, easy to fabricate, and can be used for long-term continuous IOP measurements. It presents a new approach for microfluidic-based IOP sensors and offers a novel method for the daily care of patients with glaucoma.

Quality by design steered approach for co-encapsulation of timolol maleate and dorzolamide hydrochloride in injectable liposomes

Glaucoma is caused by high intraocular pressure, which can causes blindness. Combinations of timolol and dorzolamide are used for its treatment with a requirement of multiple dosing with dosing being twice or four times a day. Conventional eye drops have poor pre-corneal retention and is thus less available for action. This study utilizes principles of Quality by Design for formulation of injectable liposomes coloaded with timolol maleate and dorzolamide HCl, which overcomes limitations of conventional eye drops. For implementation of Quality by Design principles a systematic approach involving defining Quality Target Product Profile, identification of Critical Quality Attributes, mapping Critical Quality Attributes to Critical Process Parameters and Critical Material Attributes, Failure Mode and Effect Analysis based risk assessment, Taguchi screening, and 32 full factorial Design of Experiments design were utilized. A robust model for formulation of coloaded liposomes was successfully developed. Design of Experiments approach allowed to obtain optimized batch having particle size of 116.1 nm, encapsulation efficiency of dorzolamide HCl of 72.12 % and encapsulation efficiency of timolol maleate of 71.94 %. In-vitro drug release showed a sustained release for 4 days. The prepared formulation was in the desired osmolarity range. Biosafety was proved using histopathological characterization. In-vivo studies for assessing the Intra Ocular Pressure reduction showed that there was no significant difference in Intra Ocular Pressure reduction between prepared liposomes and marketed formulation but were superior than marketed formulation because of less fluctuations in Intra Ocular Pressure. Prepared coloaded injectable liposomes lays the foundation for further research in the area and can be translated from to bench side for commercial clinical use.

Long-term Visual Field Variability in Patients with Primary Open-angle Glaucoma

Purpose: To investigate factors associated with variability in the longitudinal visual field (VF) test in patients with primary open-angle glaucoma (POAG).Methods: This retrospective study enrolled POAG patients with VF ≥ 12 who were followed up for ≥ 6 years. First, 52 total deviation values of VF series for each eye were linearly regressed against time (years), and the root mean square error (RMSE) of the residuals was used to measure long-term pointwise VF variability. The mean deviation (MD) of the VF series for each eye was linearly regressed against time (years), and the RMSE of the residuals was used to measure long-term global VF variability. Using hierarchical clustering, variable clustering was performed to select variables and Spearman’s correlation was used as a similarity index. We fitted a mixed effect linear regression model and evaluated factors associated with the long-term VF variability in each regression model.Results: The study included 246 eyes of 157 patients with POAG. Worse baseline peripapillary retinal nerve fiber layer (RNFL) thickness, lower baseline intraocular pressure (IOP), lower mean IOP, greater IOP fluctuation, and a faster VF decay rate were associated with increased long-term pointwise VF variability in the RNFL thickness model (all &lt;i&gt;p&lt;/i&gt; ≤ 0.037). Worse baseline MD, lower baseline IOP, lower mean IOP, and faster VF decay rate were associated with increased long-term global VF variability in the MD model (all &lt;i&gt;p&lt;/i&gt; ≤ 0.035).Conclusions: Lower baseline and mean IOP, greater IOP fluctuation, worse glaucoma severity, and a faster VF decay rate were associated with greater long-term VF variability in patients with POAG. These factors should be considered when evaluating VF progression.

Exploring the relationship between accommodation and intraocular pressure: a systematic literature review and meta-analysis.

To investigate the relationship between accommodation and intraocular pressure (IOP). Systematic literature search and meta-analysis following PRISMA guidelines was conducted on studies analyzing the relationship between accommodation and intraocular pressure. After removal of duplicates, title and abstract screening, full-text analysis was performed to select relevant articles and meta-analysis was then conducted as well. Of the 1357 records identified, 17 met the selection criteria and were included. Overall, all studies showed that accommodation can influence IOP levels and meta-analysis indicated a significant IOP reduction of 1.10 mmHg (95%CI, -1.77; -0.42) following accommodative stimulus in healthy individuals, albeit with high heterogeneity among studies. Differences in IOP changes between emmetropic and progressing myopic individuals were not significant. Controversial results were obtained in patients with glaucoma with significantly lower IOP fluctuations being noted in eyes with previous trabeculectomy; however, the clinical heterogeneity of enrolled patients among studies made it not possible to combine results. Type of accommodative task, extraocular muscle contraction, head and body position all could potentially play a role in the measured IOP changes with, interestingly, near reading on a smartphone suggesting IOP increase. Accommodation has an impact on IOP measurements and, overall, determines IOP decrease in healthy individuals. While such variations might not hold clinical significance for individuals in good health, their impact in patients with glaucoma should be considered. Further studies focused on specific components of such relationship are required to elucidate their individual impact and to define their potential role as non-pharmacological strategies to reduce IOP levels in selected patient categories.

Selective Laser Trabeculoplasty vs Medical Therapy for the Treatment of Open-angle Glaucoma or Ocular Hypertension: a Systematic Review and Meta-analysis of Randomized Controlled Trials.

Selective laser trabeculoplasty (SLT) and medical therapy groups displayed comparable intraocular pressure (IOP) at most follow-ups. SLT was associated with significantly decreased rates of glaucoma surgeries, antiglaucomatous medications, and ocular adverse effects. To evaluate the efficacy and safety of selective laser trabeculoplasty (SLT) compared to medical therapy in the treatment of open-angle glaucoma (OAG) or ocular hypertension (OHT). A systematic search was performed in PubMed, Embase, Cochrane Library and Web of Science databases. Randomized controlled trials (RCTs) comparing SLT with medical therapy were included. We computed mean differences (MDs) or standardized mean differences (STDs) for continuous endpoints and risk ratios (RRs) for binary endpoints, with 95% confidence intervals (CIs). Heterogeneity was assessed with I2 statistics. Software R, version 4.2.1, was used for statistical analyses. Subgroup analyses were performed on treatment-naive patients and on the class of drugs in the medical therapy group. Fourteen RCTs comprising 1,706 patients were included, of whom 936 were submitted to SLT. Medical therapy was associated with a significantly improved IOP at 1 month and a higher proportion of patients achieving ≥20% IOP reduction. There were no significant differences between groups in IOP at 2, 3, 6, and 12 months, IOP fluctuation, rate of eyes at target IOP, visual field, and quality of life. The SLT group exhibited significantly decreased rates of glaucoma surgeries, antiglaucoma medications, and ocular adverse effects. SLT demonstrated comparable efficacy to medical therapy in IOP control at most follow-ups, along with favorable impacts on critical treatment-related factors. Our findings support SLT as a safe and effective treatment for OAG or OHT.

Assessing Glaucoma Severity and Progression in Individuals with Asymmetric Axial Length: An Intrapatient Comparative Study

PurposeTo investigate whether there is a difference in inter-eye glaucoma severity and progression in patients with asymmetric axial length DesignLong-term observational study ParticipantsPatients over 20 years of age who had been diagnosed with glaucoma at Seoul National University Hospital, Seoul, Korea, between 2010 and 2020. MethodsPatients diagnosed with glaucoma in both eyes with an axial length difference of more than 1.0 mm were included. Each individual’s eyes were classified into “longer eye” and “shorter eye,” and the baseline and follow-up clinical data were analyzed using the paired test. Main Outcome MeasuresDifferences in clinical characteristics in patients with asymmetric axial length ResultsA total of 190 eyes of 95 glaucoma patients with asymmetric axial length were included in the study. The patients’ mean age was 51.2 ± 12.3 years, and the mean follow-up period was 10.1 ± 3.9 years. There was no difference in the baseline intraocular pressure (IOP) or central corneal thickness (CCT) between longer eyes and shorter eyes. Among the baseline disc parameters, ovality index, beta-zone and gamma-zone parapapillary atrophy (PPA) area were larger in the longer eyes. In the baseline OCT data, the retinal nerve fiber layer (RNFL) thickness and ganglion cell-inner plexiform layer (GCIPL) thickness were thinner in the longer eyes. According to a baseline visual field (VF) test, the mean deviation (MD) and visual field index (VFI) values were significantly lower in the longer eyes. Based on an analysis of glaucoma progression, the rate of change of superior GCIPL (longer eyes : -0.65 μm/yr, shorter eyes : -0.40 μm/yr) , MD (longer eyes : -0.40 dB/yr, shorter eyes : -0.21 dB/yr) , and VFI (longer eyes : -0.92 %/yr, shorter eyes : -0.46 %/yr) were larger in the longer eyes. The greater the difference between the mean IOP and beta-zone PPA area between inter-eyes, the greater the difference in the rate of change of RNFL and GCIPL. Additionally, the greater the difference in IOP fluctuation, the greater the difference in the rate of change between MD and VFI. ConclusionsWhen there was an axial length difference of more than 1.0 mm, glaucoma tended to be more severe and to progress faster in the longer eyes. The inter-eye difference in glaucoma progression rate is related to both mean IOP and IOP fluctuation.

Liquid-alloy-based dual sensing elements contact lens sensor for continuous intraocular pressure monitoring

Intraocular pressure (IOP) fluctuation is an independent risk factor for glaucoma and a key to clarify its pathogenesis. We have developed a contact lens integrated with a conformal LC resonance circuit made of liquid alloy (Galinstan) for non-invasive continuous IOP monitoring. The contact lens is fabricated using polydimethylsiloxane (PDMS), in which the LC resonance circuit can sense corneal strain proportionally caused by IOP variation. The Galinstan configuration is formed to the designed pattern by UV-laser treating the carbon-doped Ecoflex (c-Ecoflex) stamps and then selectively transferring the Galinstan onto the stamp to form the LC resonance circuit pattern. The tests conducted on silicone model eyes demonstrate high sensitivity in the frequency responses to variations in IOP, reaching 649 ppm/mmHg. IOP measurement on human eyes during head-down tilt bedrest confirms its applicability. With process optimization, this contact lens sensor has great potential for mass production and wide application in monitoring IOP.

Anterior Chamber Angle and Intraocular Pressure Control After Phacoemulsification in Primary Angle Closure With Different Mechanisms.

Different mechanisms of angle closure represented distinct aspects of intraocular pressure (IOP) control after phacoemulsification. Classification of angle closure mechanisms is necessary for postoperative IOP management and glaucoma progression in primary angle closure eyes. To investigate the relationship between the anterior chamber angle (ACA) characteristics, measured by swept-source anterior segment optical coherence tomography (SS AS-OCT), and intraocular pressure (IOP) control after phacoemulsification in eyes with primary angle closure disease (PACD) with different angle closure mechanisms. PACD eyes were classified into 3 groups according to angle closure mechanisms using preoperative SS AS-OCT images; pupillary block (PB), plateau iris configuration (PIC), exaggerated lens vault (ELV). This retrospective, clinical cohort study included eighty-five eyes of 85 PACD patients: 34 with PB, 23 with PIC, and 28 with ELV. ACA parameters were measured preoperatively and 1 month postoperatively using SS AS-OCT. IOP measurements were performed preoperatively and during 6 months postoperatively. Postoperative IOP reduction and fluctuation were calculated, and their correlations with SS AS-OCT parameters were analyzed. PIC group showed the lowest postoperative IOP reduction compared with the other groups ( P =0.023). Preoperative ACA measurements were significantly associated with postoperative IOP reduction in ELV and PB groups, while postoperative measurements were in PIC group. Preoperative and postoperative change of iridotrabecular contact (ITC) index and area were correlated with postoperative IOP reduction in PB and ELV groups but not in PIC group. Postoperative ITC index ( P =0.031) and area ( P =0.003) showed significant correlations with postoperative IOP fluctuation only in PIC group. SS AS-OCT parameters including ITC index and area showed different associations with postoperative IOP control, which should be considered in determination of lens extraction and treatment of PACD eyes.

Standardizing the diagnosis and treatment of ocular hypertension based on evidence-based medicine

Ocular hypertension (OHT) refers to a condition in which the intraocular pressure increases without causing glaucomatous optic nerve changes or visual field damage. The incidence rate of OHT in people over 40 years old is as high as 4% to 10%. According to the OHT Treatment Study (OHTS), the incidence of primary open angle glaucoma (POAG) among OHT patients is increasing year by year, so it is necessary to conduct long-term follow-up. This article elaborates on five major risk factors for the progression of OHT to POAG: age, intraocular pressure, vertical cup-disc ratio, pattern standard deviation of visual field, and central corneal thickness. It also summarizes other potential risk factors, such as long-term fluctuations in intraocular pressure, asymmetry of intraocular pressure and visual field between the two eyes, structural phenotypes of the optic disk, and optic disk hemorrhage. Predicting the risk of OHT progression to POAG based on risk factors, patients with different risk levels require different timing for treatment initiation and follow-up intervals. Those with higher risks should start preventive treatment earlier and have shorter follow-up intervals. Both drug therapy and selective laser trabeculoplasty can serve as initial treatment options for OHT. Combining evidence-based medicine research and individualized evaluation of treatment can enhance the clinical diagnosis and treatment level of OHT.

Assessing the value of the water drinking test in glaucoma-a systematic review and meta-analysis.

This systematic review and meta-analysis examines the relationship between intraocular pressure (IOP) parameters derived from the water drinking test (WDT) and diurnal IOP monitoring, and evaluates the reproducibility of the WDT and its association with future glaucomatous visual field (VF) loss. A literature search was performed on PubMed, EMBASE, and Cochrane Library from inception to 31 March 2023. Cohort, cross-sectional and observational studies reporting WDT results in glaucoma patients were included. Meta analysis with random-effect model was performed using "metafor" package in R version 3.2.1. 641 studies were identified on initial literature search. 38 studies (2479 subjects) were included in final analysis. Meta-analytic estimates of 5 studies (310 subjects) found strong positive correlation in peak IOP between the WDT and diurnal IOP monitoring (r = 0.92, 95% CI = 0.75, 1.08, p < 0.0001). However, there was only weak positive correlation for IOP fluctuation between both methods (r = 0.26, 95% CI = 0.06,0.47, p < 0.0001). Meta-analytic estimates of 3 studies (189 subjects) suggested a trend of the diurnal peak IOP being lower than that derived from the WDT (MD = -2.37 mmHg, 95% Limit of Agreement (LOA) =-5.58,0.84, p = 0.147). Two studies found that a higher WDT peak IOP was associated with greater future VF progression. Two studies demonstrated good reproducibility in peak IOP measurements for WDTs conducted across different days. In conclusion, there was a strong positive correlation between IOP peak measurements from the WDT and diurnal IOP monitoring in glaucoma patients. The WDT peak IOP demonstrated good reproducibility and may be associated with greater future VF progression.

SURGICAL DEMONSTRATION OF PRESSURE DIFFERENTIAL THROUGH AN OPTIC DISK PIT.

To demonstrate intraoperative dynamic flow through an optic disk pit. Retrospective interventional case report. Surgical management of an optic disk pit involved standard, 25-gauge, pars plana vitrectomy, induction of posterior hyaloid separation with triamcinolone stain, temporal peripapillary laser, and SF 6 gas. Intraoperatively, a remnant of stained vitreous at the optic disk head prolapsed into the optic disk pit with higher intraocular pressure but was drawn back into the vitreous cavity as the intraocular pressure was lowered. This clearly demonstrated a pressure differential across the pit. Communication between the vitreous cavity and the perineural space of the optic nerve is described histologically. Our case demonstrated dynamic flow through the optic disk pit with intraoperative fluctuation of intraocular pressure.

Thicker Inner Nuclear Layer as a Predictor of Glaucoma Progression and the Impact of Intraocular Pressure Fluctuation.

Background: Thickening of the inner nuclear layer (INL) or microcystic macular changes has been reported to be implicated in glaucoma patients, but their potential impact on disease progression remains unclear. We investigated the relationship between baseline microcystic macular edema in the INL or INL thickness and subsequent visual field (VF) progression in glaucoma patients. Methods: This retrospective observational study included primary open-angle glaucoma with follow-up exceeding 3 years. We identified macular cystic changes through Spectralis optical coherence tomography and measured the INL thickness using automated segmentation. Glaucoma progression was determined using the Guided Progression Analysis program of the Humphrey filed analyzer, calculating the mean deviation (MD) changes (dB/year). Results: Microcystic macular changes were observed in 12 (7.5%) of 162 patients. Patients with microcystic macular change had thicker INL thickness than those without it (p = 0.010). Progressors had a higher probability of having microcystic macular changes and a thicker average INL thickness than nonprogressors (p = 0.003, p = 0.019). Thicker INL thickness was associated with faster VF progression based on MD slope (dB/year) in the multivariate regression analysis (p = 0.045). Additionally, greater intraocular pressure (IOP) fluctuation was found to be associated with both a thicker INL and the presence of microcystic changes in the multivariate regression analysis (p = 0.003, 0.028). Conclusions: Increased macular INL thickness indicative of INL changes was linked to subsequent VF progression in glaucoma patients. These findings suggest that retinal inner nuclear change could serve as an indicator of progressive glaucoma.

Association of Long-Term Intraocular Pressure Variability and Rate of Ganglion Complex Thinning in Patients With Glaucoma

To evaluate the association of mean intraocular pressure (IOP) and IOP variability (IOP fluctuation [SD of IOP] and the IOP range) with the rate of ganglion cell complex (GCC) layer thinning over time in patients with glaucoma. Prospective cohort study. Participants with at least 4 visits and 2 years of follow-up of optical coherence tomography tests were included. A linear mixed-effect model was used to investigate the association of IOP parameters with the rates of GCC thinning. Subgroup analyses were conducted for eyes with early (MD ≥ -6 dB), and moderate to advanced stage (MD < -6 dB) at baseline. The cohort consisted of 369 eyes of 249 glaucoma patients (282 early glaucoma and 87 moderate to advanced glaucoma) with mean (standard deviation [SD]) age of 68.2 (10.7) years over 5.1 years of follow-up. The mean rate of GCC change was -0.59 (95% confidence interval [CI], -0.67 to -0.52) µm per year. In multivariable models, faster annual rate of GCC thinning was associated with a higher IOP fluctuation (-0.17 [95% CI, -0.23 to -0.11] µm per 1-mmHg higher, P < .001) or higher IOP range (-0.07 [95% CI, -0.09 to -0.05] µm per 1-mmHg higher, P < .001) after adjustment for mean IOP and other confounding factors. Similar results were found for early and moderate to advanced stages of glaucoma. IOP variability showed an independent association with macular change in patients with glaucoma regardless of severity at baseline, even after adjustment for mean IOP, supporting its potential value as a therapeutic target for clinical decision-making.