Minimum Intraocular Pressure Research Articles

Usefulness of Intraocular Pressure With the Ocular Response Analyzer to Predict Postoperative Hypotony Complications in Glaucoma.

To investigate the usefulness of intraocular pressure (IOP) using the ocular response analyzer to predict the occurrence of hypotony complications following trabeculectomy or bleb needling revision with mitomycin C. This study included 66 eyes of 66 patients who underwent trabeculectomy (58 eyes of 58 patients) or bleb needling (8 eyes of 8 patients) with mitomycin C. A significant predictor of hypotony complications was identified from (1) operation (trabeculectomy or bleb needling), (2) age, (3) sex, (4) disease type (primary open-angle glaucoma, primary angle closure glaucoma, or exfoliation glaucoma), (5) lens status (phakia or pseudophakia), (6) preoperative Goldmann applanation tonometry IOP, (7) preoperative central corneal thickness, (8) preoperative axial length, (9) preoperative anterior chamber depth, (10) preoperative corneal hysteresis, (11) preoperative corneal resistance factor, (12) preoperative corneal compensated IOP (IOPcc), and (13) minimum IOP (IOP value when hypotony complications occurred, otherwise the minimum IOP during 3 months from trabeculectomy or bleb needling) using multivariate logistic regression. The probability of the occurrence of hypotony complications tended to increase by applying higher cutoff values to preoperative Goldmann applanation tonometry IOP and IOPcc, but not lower cutoff values to the minimum IOP. Multivariate logistic regression suggested that higher preoperative IOPcc and pseudophakia were significant predictors of the occurrence of hypotony complications (P = 0.0062 and 0.0069, respectively). Higher preoperative IOPcc and pseudophakia were significant predictors of the occurrence of hypotony complications. It is useful to measure IOP using the ocular response analyzer before trabeculectomy.

Optic Nerve Head Pulsatile Displacement in Open-Angle Glaucoma after Intraocular Pressure Reduction Measured by Optical Coherence Tomography: A Pilot Study.

This study investigated the effect of intraocular pressure (IOP) reduction on pulsatile displacement within the optic nerve head (ONH) in primary open-angle glaucoma (POAG) patients with and without axial myopia. Forty-one POAG patients (19 without myopia, 9 with axial myopia and 13 glaucoma with no intervention) participated. Swept-source optical coherence tomography (OCT) videos of the ONH were obtained before and after IOP-lowering treatment (medical or surgical) achieving a minimum IOP drop of 3 mmHg. A demons registration-based algorithm measured local pulsatile displacement maps within the ONH. Results demonstrated a significant 14% decrease in pulsatile tissue displacement in the non-myopic glaucoma cohort after intervention (p = 0.03). However, glaucoma patients with axial myopia exhibited no statistically significant change. There were no significant changes in the pulsatile ONH deformation in the control group. These findings suggest a potential link between IOP reduction and reduced pulsatile displacement within the ONH in POAG patients without myopia, offering new insights into the disease's pathophysiology and warranting further investigation into underlying mechanisms and clinical implications.

To Determine Mean Changes in Intraocular Pressure during Hemodialysis in patients of End Stage Kidney Disease

Aim: To determine mean changes in intraocular pressure (IOP) during hemodialysis (HD) in patients of chronic renal failure Study design: Descriptive case series Place and duration of study: Department of Nephrology, Allied Hospital, Faisalabad, from 15/06/2016 to 15/09/2016 Methodology: End stage renal patients meeting the inclusion criteria on hemodialysis were included in the study. Written informed consent was obtained. After taking detailed history and clinical examination, intraocular pressure was measured just before and one hour after the initiation of HD using perkin’s hand held tonometer. Results: The mean± SD age of patients was 53.8±8.81. The minimum IOP was 11.20mmHg before hemodialysis and maximum was 16.80mmHg. Mean±SD was 14.08±1.38. Similarly minimum IOP after dialysis was 12 mm Hg and maximum was 19.0mm Hg, with a mean of 15.3. IOP in males before HD was 14.09±1.33. However after dialysis was 15.56±1.7. Thus the change in IOP seen in males was 1.6 ± 0.89 and in females was 14.08±1.46 and after dialysis was 15.13±1.45. Thus the calculated IOP change in females was 1.37±0.98. Chi square value was 2.67. p value observed was 0.263. Conclusion: There is significantly increased IOP during hemodialysis. Keywords: CRF, end-stage renal disease (ESRD), IOP, hemodialysis (HD).

Suppression of Diurnal (9AM-4PM) IOP Fluctuations with Minimally Invasive Glaucoma Surgery: An Analysis of Data from the Prospective, Multicenter, Single-Arm GEMINI Study.

PurposeThis study analyzes diurnal IOP data (9AM, 12PM, 4PM) from a prospective 12-month trial of the OMNI Surgical System in open-angle glaucoma (OAG) patients with the aim of evaluating effect of MIGS surgery on the amplitude of the diurnal IOP profile pre- and postoperatively.SettingFifteen ophthalmology practices and surgery centers located in 14 states in the United States.DesignProspective, multicenter, IRB approved study. Patients treated with canaloplasty (360°) and trabeculotomy (180°). Patients had cataract and mild–moderate OAG with intraocular pressure (IOP) ≤33 mmHg on zero to four hypotensive medications.MethodsPost-hoc analysis of diurnal IOP data from the multicenter GEMINI study. Analysis includes comparison of IOP preoperatively and at month 12 for each of the diurnal time points, 9AM, 12PM, 4PM, change in magnitude of spread between the maximum IOP and minimum IOP for each patient and the proportions of patients preoperatively and at month 12 with IOPs at or below 25, 21, 18, and 15 mmHg, average variability (standard deviation of the 9AM, 12PM, and 4PM IOP) preoperatively and at month 12.ResultsA total of 128 patients included in this analysis. IOP at each diurnal timepoint was significantly lower postoperatively (p<0.0001). The difference between highest and lowest IOP measurement for each patient averaged 2.8 mmHg preoperatively (SD 2.4, MAX 14, MIN 0) and 1.8 mmHg (SD 1.7, MAX 10, MIN 0) month 12 (P<0.00001). The proportion with IOP ≤ to 25, 21, 18, and 15 mmHg increased; 75%–97%, 27%–88%, 1%–79%, and <1%–56%, respectively. The average variability was greater at all time points preoperatively (P<0.0001).ConclusionThis study demonstrates that eyes with OAG can benefit from an overall decreased IOP and degree of IOP fluctuations for as long as 12 months after surgical treatment with canaloplasty and trabeculotomy.

The Utility of iCare HOME Tonometry for Detection of Therapy-Related Intraocular Pressure Changes in Glaucoma and Ocular Hypertension

To assess whether iCare HOME rebound tonometry can detect therapy-related changes during self-monitoring of intraocular pressure (IOP). Prospective clinical trial. A total of 43 eyes (n= 27 subjects) with open-angle glaucoma or ocular hypertension were enrolled during standard-of-care clinic visits. Participants were grouped into control eyes managed on stable therapy (n= 18 eyes) or therapy change eyes undergoing selective laser trabeculoplasty (SLT, n= 8 eyes), initiating topical therapy (n= 8 eyes), or adding a second medication to existing monotherapy (n= 9 eyes). Subjects recorded IOP 4 times daily for 1 week using iCare HOME tonometry. Upon tonometer return, subjects underwent SLT or new medication start; an additional week of iCare HOME measurements was collected after 4 to 6 weeks. Control subjects recorded an additional week of measurements after 6 weeks. Measurements were grouped into 4 time periods (5-10 am, 10 am to 3 pm, 3-8 pm, 8 pm to 1 am). Goldmann applanation tonometry (GAT) was performed at each study visit for comparison. Detection of therapy response defined as an IOP reduction of ≥20%. For eyes that demonstrated a therapy response by GAT (n= 11), iCare HOME detected a therapy response in 90.9% of eyes in ≥1 time period and 45.5% of eyes in all 4 time periods. In eyes without a GAT-measured therapy response (n= 14), iCare HOME detected a response for 71.4% (n= 10) of eyes in ≥1 time period and for 7.1% of eyes (n= 1) at all 4 time periods. In treatment eyes, intraday and interday average minimum and maximum IOP, as well as interday IOP range, were significantly reduced after therapy without a significant change in intraday IOP range. Control group eyes did not demonstrate a significant change in average IOP minimum, maximum, or range between study weeks. Home tonometry with iCare HOME reliably detects therapy-related IOP changes in patients with glaucoma and ocular hypertension. Treatment responses correlated well with in-office GAT and may detect treatment responses missed by GAT. Intraocular pressure measurements via home tonometry provide additional clinical information regarding intraday and interday IOP fluctuation beyond standard of care in office GAT measurements. The iCare HOME is a valuable tool to monitor therapeutic efficacy in patients with glaucoma.

Correlation between intraocular pressure obtained with water drinking test versus modified diurnal tension curve measurement in pseudoexfoliation glaucoma.

The aim of this paper was to study the correlation and agreement between the intraocular pressure (IOP) peak value and fluctuations detected with the modified diurnal tension curve (mDTC) and the water drinking test (WDT) in pseudoexfoliation glaucoma (XFG) patients. This prospective observational study enrolled 42 eyes of 42 XFG patients. The IOPs were measured at 2-h intervals from 8 am to 4pm with a Goldmann applanation tonometer by a single observer to establish the mDTC. The WDT was then performed between 4 and 5pm on the same day and the IOP was measured 4 times at 15-min intervals after water ingestion. The IOPpeak, IOPmean, IO min, and IOPfluctuation were measured with both the mDTC and WDT. The paired sample t test, Spearman's correlation coefficient and Bland-Altman plots were used for statistical analysis. The mean age of the 42 patients consisting of 24 females and 18 males was 66.9 ± 6.8years, and the mean central corneal thickness was 517.7 ± 29.1µm. The mean values with the mDTC and WDT measurements were 15.05 ± 2.75mmHg and 17.17 ± 3.25mmHg (p ≤ 0.0001, r = 0.884) for IOPmean, 16.76 ± 3.45mmHg and 18.92 ± 3.94mmHg (p ≤ 0.0001, r=0.787) for IOPpeak, and 13.61 ± 2.56mmHg and 15.11 ± 2.84mmHg (p ≤ 0.0001, r=0.824) for IOPmin, respectively, and a positive correlation was present between these values. There was a positive correlation between the peak, minimum, and mean IOP values determined using the mDTC and WDT in treated XFG patients. WDT can be used as an alternative in the assessment of the IOP in these patients as a more practical method.

Home Self-tonometry Trials Compared with Clinic Tonometry in Patients with Glaucoma

This study examined characteristics of intraocular pressure (IOP) as measured during home tonometry in comparison with in-clinic tonometry in patients with glaucoma. Retrospective cross-sectional study of glaucoma patients who completed 1 week of self-tonometry at a single academic center. Patients with glaucoma who completed home tonometry trials with the iCare HOME tonometer (iCare USA) for any reason. Home IOP measurements were compared with in-clinic tonometry performed during the 5 visits preceding home tonometry. Maximum daily IOP was correlated to time of day. Generalized estimating equations were used to evaluate patient characteristics and clinic-derived variables that predicted differences between home and clinic IOP. IOP mean, maximum, minimum, range, standard deviation and coefficient of variation were compared between clinic and home tonometry. IOP mean daily maximum (MDM) and mean daily range were calculated to describe recurrent IOP spiking. A total of 107 eyes from 61 patients were analyzed. Mean age was 63.2 years (standard deviation [SD], 14.0 years) and 59.0% were women. Mean clinic and home IOPs were 14.5 mmHg (SD, 4.7 mmHg) and 13.6 mmHg (SD, 5.1 mmHg). Home tonometry identified significantly higher maximum IOP, lower minimum IOP, and greater IOP range than clinic tonometry (P < 0.001). Maximum daily IOP occurred outside of clinic hours (8 am-5 pm) on 50% of days assessed and occurred between 4:30 am and 8 am on 24% of days. Mean daily maximum IOP exceeded maximum clinic IOP in 44% of patients and exceeded target IOP by 3 mmHg, 5 mmHg, or 10 mmHg in 31%, 15%, and 6% of patients, respectively. Patient characteristics that predicted significant deviations between MDM and mean clinic IOP or target IOP in multivariate models included younger age, male gender, and absence of prior filtering surgery. Self-tonometry provides IOP data that supplements in-clinic tonometry and would not be detectable over daytime in-clinic diurnal curves. A subset of patients in whom home tonometry was ordered by their glaucoma clinician because of suspicion of occult IOP elevation demonstrated reproducible IOP elevation outside of the clinic setting. Such patients tended to be younger and male and not to have undergone previous filtering surgery.

Laser peripheral iridoplasty for chronic angle closure.

Laser peripheral iridoplasty for chronic angle closure.

Effect of Near Work on Intraocular Pressure in Emmetropes.

Objective To determine whether accommodation induced by reading alters intraocular pressure (IOP) in healthy, young, emmetropic adults and to document the duration and magnitude of this effect. Design Cross-sectional study. Participants. Fifteen healthy, emmetropic young adults. Methods Subjects performed 20 minutes of near work (reading at 33 cm) followed by 20 minutes of far work (reading at 520 cm) while IOP was measured using an iCare tonometer at baseline and every 5 minutes thereafter. Statistical analysis was performed using repeated measures ANOVA. Main Outcome Measures. Intraocular pressure. Results IOP decreased significantly compared to baseline IOP after 10 minutes of near work (average change of −1.60 ± 2.2 (SD) mm Hg, p < 0.05). IOP remained lower than baseline IOP throughout all subsequent near and far work. The difference in IOP at the end of experimentation compared to baseline IOP was −1.87 ± 1.81 mm Hg (p < 0.05). IOP remained lower than baseline IOP throughout all subsequent near and far work. The difference in IOP at the end of experimentation compared to baseline IOP was −1.87 ± 1.81 mm Hg (Conclusions Near work decreases IOP in healthy emmetropes, and this effect is sustained for at least 20 minutes after discontinuing prolonged near work. Providers may need to consider this effect when measuring IOP in clinical practice.

Clinical Signs and Intraocular Pressure Changes in Patients with Orbitozygomatic Complex Fractures.

The study investigated the association between intraocular pressure changes and clinical ocular signs in 51 patients with orbitozygomatic complex fractures. Diplopia, chemosis, enophthalmos, subconjunctival haemorrhage, periorbital ecchymosis and extraocular muscles entrapment were assessed. Intraocular pressure was measured in mmHg at different time intervals with Perkins and Goldman tonometers; within first 3days of injury (T1), 24h post-elevationwithin 3-14 days of injury (T2), 1month after initial treatment assessment (T3), 2months after initial treatment assessment (T4), and 3months after initial treatment assessment (T5). Intraocular pressure changes between T2/T1 and T3/T1 were analysed as change 1 and change 2, respectively, with paired t test. Significance was set at p < 0.05. Minimum intraocular pressure recorded in the affected eye was 5mmHg at T1 and T2, while maximum intraocular pressure was 28mmHg at T1. Mean intraocular pressure at T1 and T2 was 15.90 ± 4.73mmHg and 16.80 ± 4.43mmHg, respectively. All eye signs had completely resolved at T3 except enophthalmos, which persisted till T5. Statistical significant relationship exist between orbitozygomatic complex fracture and enophthalmos (T1: p = 0.04). subconjunctival haemorrhage (T2: p = 0.003), periorbital ecchymosis (T2: p = 0.005),and T3: p = 0.001). Chemosis, diplopia, enophthalmos, periorbital ecchymosis and subconjunctival haemorrhage showed positive contributory effect to intraocular pressure elevation in orbitozygomatic complex fracture.

Changes in corneal endothelial cell density in patients with primary open-angle glaucoma.

BACKGROUNDGlaucoma is a group of diseases characterized by a specific pattern of optic nerve neuropathy and retinopathy. Increasing evidence demonstrates glaucoma associated corneal endothelium loss. Direct-compression mechanism due to elevated intraocular pressure (IOP), cell toxicity after long term exposure to preservatives and glaucoma surgery have been reported to be the possible mechanism. Herein, we compare the specular endothelial microscopy in primary open-angle glaucoma (POAG) patients and healthy controls of the same age group to observe the corneal endothelium changes and the correlations to the mean IOP in a Chinese case control study.AIMTo investigate corneal endothelial cell density in Chinese patients with POAG.METHODSA case control study was performed on 60 eyes of 60 patients with POAG. Exclusion criteria included history of corneal diseases, intraocular diseases, contact lens use, ocular trauma or surgery (including intraocular surgery and laser treatment), congenital abnormalities or systemic diseases such as diabetes. Intraocular pressure was measured using Goldmann tonometry. Indirect specular microscopy (TOPCON SP-2000P) was performed on central corneas and endothelial images were acquired. Endothelial cell density, area and cell counts were analyzed.RESULTSEndothelial cell density was 2959 ± 236 cells/mm2 in healthy controls and 2757 ± 262 cells/mm2 in patients with POAG. The POAG eyes had significantly lower endothelial cell density compared to healthy control eyes (P < 0.001). In the POAG group, endothelial cell density was 2686 ± 233 cells/mm2 in the patients receiving medication and 2856 ± 272 cells/mm2 in the untreated subgroup. The eyes receiving medication had significantly lower endothelial cell density compared to untreated eyes. There was a negative correlation between cell density and mean IOP (r = −0.286, P = 0.004), positive correlation between the average cell area and mean IOP (r = 0.228, P = 0.022), maximum cell area and mean IOP (r = 0.218, P = 0.029) and minimum cell area and mean IOP (r = 0.290, P = 0.003). The percentage of hexagonal cells was not correlated with mean IOP.CONCLUSIONPatients with POAG have lower corneal endothelial cell density than healthy controls of the same age. This may be attributed to mechanical damage from elevated IOP and toxicity of glaucoma medications.

Evaluation of Early Postoperative Intraocular Pressure for Success after Ex-Press Surgery.

ABSTRACTAimThe aim of this study is to identify target levels of early postoperative intraocular pressure (IOP) associated with successful trabeculectomy using an Ex-Press glaucoma shunt.Materials and methodsThis was a retrospective single-facility study. We enrolled 158 glaucoma patients who underwent trabeculectomy with Ex-Press and were followed for >1 year, and investigated risk factors for the failure of Ex-Press surgery. We examined age, sex, central corneal thickness (CCT), number of preoperative glaucoma medications, simultaneous performance of cataract surgery, history of trabeculotomy, hypertension (HT), diabetes mellitus (DM), subtype of glaucoma, and early postoperative IOP (minimum, 2 weeks, 1 month, and 3 months).ResultsEx-Press surgery could significantly decrease IOP. Success rates at 1, 2, 3, and 4 years were 91.1, 86.1, 82.5, and 78.1%, respectively. Factors significantly affecting the success rate included age, the number of preoperative glaucoma medications, and early postoperative IOP. The IOP cutoff values of minimum IOP for the success of Ex-Press surgery was 5 mm Hg.ConclusionsYounger age, a high number of preoperative glaucoma medications, and high IOPs in the early postoperative period were found to be the risk factors for failure of Ex-Press surgery. Considering hypotonic complications, it is desirable to control the minimum IOP from 3–5 mm Hg within 2 weeks after surgery. According to our calculations, target IOPs at 2 weeks, 1 month, and 3 months after Ex-Press surgery should be 8 mm Hg, 10 mm Hg, and 14 mm Hg, respectively.Clinical significanceWe thought that Ex-Press surgery might require lower IOP in the early postoperative period than conventional trabeculectomy.How to cite this articleTojo N, Hayashi A, et al. Evaluation of Early Postoperative Intraocular Pressure for Success after Ex-Press Surgery. J Curr Glaucoma Pract 2019;13(2):55–61.

Longitudinal Changes in Bleb Height, Vascularity, and Conjunctival Microcysts After Trabeculectomy.

The objective of this article was to study longitudinal changes in bleb morphology (presence of microcysts and bleb height and vascularity) in subjects enrolled in the Singapore 5-Fluorouracil (5-FU) trabeculectomy study. Retrospective subgroup analysis of a randomized controlled trial. Following trabeculectomy with either 5-FU or placebo, subjects were reviewed at day 1, weeks 1, 2, and 3, and months 3, 6, 9, 12, 16, 20, 24, 28, 32, and 36 and intraocular pressure (IOP), presence of microcysts and bleb height and vascularity graded and recorded. Statistical analyses were used to investigate baseline factors (demographics, eye drops use, IOP, treatment type, and comorbidities) that might account for long-term bleb changes and assess the influence of bleb morphology on mean, maximum, minimum, and variation in IOP following trabeculectomy. One hundred fifty-nine (61.2%) subjects completed follow-up and 71 subjects (44.7%) received 5-FU. Proportion of subjects with microcysts increased posttrabeculectomy till weeks 3 and 6 in 5-FU and placebo-treated eyes, respectively, before decreasing. Presence of microcysts at day 1 and week 2 was associated with lower mean (P=0.027 to 0.033), maximum (P=0.040), and minimum IOP (P=0.010). Mean bleb height decreased over 36 months and at months 20 and 36 was associated with maximum (P=0.031) and minimum IOP (P=0.032), respectively. Mean bleb vascularity decreased till month 9 and remained fairly constant after. Microcysts seen early posttrabeculectomy is associated with lower IOP. Blebs reduce in height as they remodel and the relationship between bleb vascularity and IOP is complex.

A Randomized, Controlled Phase I/II Study to Evaluate the Safety and Efficacy of MGV354 for Ocular Hypertension or Glaucoma

To assess the clinical safety, tolerability, and efficacy of topically administered MGV354, a soluble guanylate cyclase (sGC) activator, in patients with ocular hypertension (OH) or glaucoma. Double-masked, randomized, and vehicle-controlled study. Parts 1 and 2 evaluated safety and tolerability to identify the maximum tolerated dose (MTD) of once-daily MGV354 in 32 healthy volunteers (Part 1) and 16 patients with OH or glaucoma (Part 2) at a single clinical site. Part 3 was a multisite trial that evaluated intraocular pressure (IOP)-lowering efficacy of the MTD administered nightly for 1week in 50 patients with minimum IOP of 24mm Hg at 8 AM, with a main outcome measure of mean diurnal IOP at day 8 compared to baseline (ClinicalTrials.govNCT02743780). There was no difference in favor of MGV354 for IOP lowering; change from baseline to day 8 in mean diurnal IOP was -0.6mm Hg for MGV354-treated patients and -1.1mm Hg for vehicle-treated patients in Part 3, with a confidence interval of -0.7 to 1.7. The most common adverse events reported after MGV354 administration were conjunctival and ocular hyperemia. Overall, MGV354 0.1% demonstrated no statistically significant effect compared to vehicle in lowering IOP based on the study's main outcome measure. MGV354 produced ocular hyperemia consistent with its pharmacology.

Clinical management outcomes of childhood glaucoma suspects.

PurposeTo investigate the outcomes of childhood glaucoma suspects.DesignRetrospective case series.MethodsRecords of childhood glaucoma suspects were identified using financial claims data; medical history, baseline biometric and exam findings were recorded. Conversion from suspect to glaucoma was determined based on the Childhood Glaucoma Research Network criteria. The study adheres to the tenets of the Declarations of Helsinki.Results214 subjects were enrolled, with median age at initial presentation of 6.37 years (interquartertile range: Q1 = 2.46, Q3 = 8.90). 22 (10.2%) subjects developed glaucoma, 64 (29.9%) had ocular hypertension but no glaucoma, 9 (4.2%) had high-risk condition or syndrome without either ocular hypertension or glaucoma after a mean follow up of 39 +/- 34 months. Neither a family history of glaucoma nor patient gender was significantly different between the groups. 40.2% of subjects (86 of 214) had two or more episodes of intraocular pressure (IOP) > 21 mmHg, among which 25.6% (22 of 86) developed glaucoma after a mean duration of 32.8 +/- 33.5 months.ConclusionsUp to 25% of children with 2 or more episodes of elevated IOP may develop glaucoma. In 50% of suspects who converted to glaucoma, elevated IOP was not present at the initial evaluation. There is no significant difference in gender, family history, or baseline central corneal thickness between suspects who developed glaucoma compared to the rest. While suspects who converted to glaucoma had higher average, maximum and minimum IOP measurements, there is no clear cutoff between the groups.

Long-term Reliability of Diurnal Intraocular Pressure Patterns in Healthy Asians.

PurposeTo determine the long-term repeatability of diurnal intraocular pressure (IOP) patterns in healthy Asian subjects without glaucoma.MethodsTwenty-three eyes in 23 healthy Asian subjects without glaucoma underwent diurnal IOP measurements using Goldmann applanation tonometry every 2 hours from 9 AM to 11 PM during two visits that were 8 weeks apart. To validate repeatability between visits, we calculated intra-class correlation coefficients (ICCs) mean IOP, peak IOP, minimum IOP, and IOP fluctuation at each time point and expressed the results as the difference between peak IOP and minimum IOP or as the standard deviation of all diurnal IOP values in the diurnal IOP curve.ResultsIOP repeatability was excellent at all time points, with ICCs ranging from 0.812 to 0.946 (p < 0.001). The 9 AM IOP showed the best repeatability between visits (ICCs, 0.946). Repeatability of mean IOP, peak IOP, and minimum IOP was also excellent (ICCs ranging from 0.899 to 0.929). However, IOP fluctuations showed poor repeatability, with an ICC lower than 0.15.ConclusionsLong-term repeatability of diurnal IOP patterns in healthy Asian subjects was excellent. These findings suggest that IOP measurements at standardized times of the day will be useful for assessing the effectiveness of glaucoma therapy.

Correlation between short-term and long-term intraocular pressure fluctuation in glaucoma patients.

PurposeWe investigated correlations between short-term and long-term intraocular pressure (IOP) fluctuations.MethodsWe examined 50 eyes of glaucoma patients who were followed for >2 years. We measured short-term IOP fluctuation using a Triggerfish® contact lens sensor (CLS). The short-term IOP fluctuation (mVeq) was defined as the difference between the maximum value and the minimum value measured during the 24-hour course with CLS. The long-term IOP fluctuation was defined by four parameters: 1) the mean IOP (mmHg) determined during follow-up; 2) the IOP difference, which was defined as the difference between the maximum IOP and the minimum IOP; 3) the standard deviation of IOP; and 4) the peak IOP, which was defined as the maximum IOP. Correlations between these parameters and the short-term IOP fluctuation were examined.ResultsThe mean follow-up period was 5.4 years. The average IOP was 15.0±4.0 mmHg. The range of short-term IOP fluctuation identified with CLS was significantly correlated with all the four long-term IOP fluctuation parameters.ConclusionShort-term IOP fluctuations were found to be associated with long-term IOP fluctuations. Examination of 24-hour IOP fluctuations with the CLS might be useful for predicting the long-term IOP fluctuation.

Diurnal Intraocular Pressure and the Relationship With Swept-Source OCT-Derived Anterior Chamber Dimensions in Angle Closure: The IMPACT Study.

To evaluate diurnal intraocular pressure (DIOP) among individuals with primary angle closure (PAC) or primary angle-closure suspect (PACS). Additionally, the hypothesis that greater DIOP fluctuation is related to smaller angle parameters was investigated. Forty Caucasian newly referred untreated patients with bilateral PAC or PACS were recruited. Intraocular pressure (IOP) was measured hourly between 9 AM and 4 PM with Goldmann applanation tonometry. Diurnal IOP fluctuation was defined as difference between maximum and minimum IOP. Angle opening distance (AOD), trabecular-iris angle (TIA), angle recess area (ARA), and trabecular-iris space area (TISA) were measured with anterior segment optical coherence tomography (AS-OCT) in dark (0.3-0.5 lux) and light (170-200 lux) on the same day as DIOP measurements in eight angle sections. Intraocular pressure declined as the day progressed (P < 0.001), unrelated to presence of peripheral anterior synechiae (PAS). At each time point, eyes with PAS (n = 31) had significantly higher IOPs than eyes without PAS (n = 49; P = 0.043). Diurnal IOP fluctuation varied from 1.50 to 14.50 mm Hg (mean 5.99 mm Hg, SD 2.70 mm Hg). Diurnal IOP fluctuation was unrelated to PAS. Multiple-predictor models investigating association of angle dimensions and greater DIOP fluctuation were statistically significant for AOD 750 (light), ARA 750 (light and dark), TISA 500 (light), TISA 750 (light), TIA 500 (light), and TIA 750 (light and dark). Diurnal IOP variation has clinical implications given that IOP level is used to distinguish between diagnostic categories of PACS and PAC. Optical coherence tomography angle parameter measurements may predict for magnitude of IOP diurnal fluctuations in at-risk patients, which may be clinically useful when a clinical intervention is being considered.

Pseudoexfoliation syndrome: Effect of phacoemulsification on intraocular pressure and its diurnal variation

PurposeTo evaluate the effect of phacoemulsification on intraocular pressure (IOP) in pseudoexfoliation (PEX) syndrome and its diurnal variation. MethodsIn this prospective, non-comparative, interventional case series, phacoemulsification was done for patients with PEX and concomitant visually significant cataract. Follow-up examinations including IOP measurement were done at postoperative day 1, week 1, month 1, month 3, and month 6. All IOP measurements were performed twice daily: once in the morning between 8 and 10 AM and the other in the evening between 6 and 8 PM. The minimum and maximum IOP and the mean IOP were recorded. IOP variation was defined as the difference between maximum and minimum pressures. ResultsSixty-eight eyes of 68 patients were analyzed. The mean IOP dropped from 17.45 ± 3.32 mm Hg to 12.57 ± 1.58 mm Hg at 6 months. The minimum and maximum IOP dropped from 14.97 ± 3.46 mm Hg and 20.03 ± 3.39 to 11.53 ± 1.79 mm Hg and 13.01 ± 1.81 after 6 months, respectively. Diurnal IOP variation dropped from 5.06 ± 1.85 mm Hg (range 2–10) at baseline to 1.49 ± 0.93 mm Hg (range 0–4) at postoperative month 6 (p < 0.001 for all). This drop was not correlated with age and CCT, but was strongly correlated with baseline IOP variation (r = 0.847, p < 0.001). ConclusionPhacoemulsification without any additional intervention can be an attractive choice in managing the IOP and its diurnal variations in pseudoexfoliation patients, even with elevated IOP, who do not have advanced optic nerve damage.

Real-time intraocular pressure measurement during phacoemulsification in dogs &lt;i&gt;ex vivo&lt;/i&gt;

This study was performed to evaluate changes in intraocular pressure (IOP) during standard coaxial phacoemulsification using 4 different bottle heights (BHs) and 2 different incision sizes. Coaxial phacoemulsification was performed with a venturi-based machine in 8 enucleated canine eyes through 3.0 and 3.2 mm clear corneal incisions (CCIs). A pressure transducer inserted in the peripheral cornea monitored the IOP in real-time. The surgery was subdivided into 4 stages: sculpt-segment removal, irrigation/aspiration, capsular polishing and viscoelastic removal. The mean IOP and the difference between the maximum and minimum IOPs were calculated at each stage and compared. The ultrasound time and volume of irrigation fluid used were recorded. The mean IOP increased with an elevation in the BH. The mean IOP in the irrigation/aspiration stage was significantly higher than that in the sculpt-segment removal stage at the same BH. The difference between the maximum and minimum IOP at each stage was greater in the 3.2 mm than the 3.0 mm CCIs, although the mean IOP was lower with the 3.2 mm than the 3.0 mm CCIs. The ultrasound time and irrigation fluid volume were greater with the 3.2 mm than the 3.0 mm CCIs. Therefore, fluidic parameters during each stage could be reassessed and adjusted to reduce complications arising from an elevated IOP. Phacoemulsification with 3.0 mm CCIs at a lower BH might lead to less stress on the eye from IOP fluctuations, ultrasound energy and irrigation fluid.