Intraocular Pressure Variation Research Articles

Non-invasive FBG-based contact lens for continuous intraocular pressure monitoring

The intraocular pressure (IOP), or pressure inside the eye, is one of the key indicator for glaucoma diagnosis and treatment. The present work shows the design and fabrication of a non-invasive Fiber Bragg Grating (FBG) based contact lens for continuous IOP monitoring. By employing wet etching to reduce the FBG diameter, FBG based contact lens sensitivity and mechanical flexibility are enhanced. The contact lens is made of an optical fiber with a small core diameter that has an inscribed FBG of length 3 mm and is etched for a length of 40 mm to facilitate coiling the eFBG during fabrication. The soft contact lens was fabricated using flexible thin film technology with a transparent and flexible etched Fiber Bragg Grating (eFBG) integrated within flexible polydimethylsiloxane (PDMS) for sensing corneal deformations brought about by IOP variations. Experimental studies on the bionic eyeball model show that the Bragg wavelength shift is highly linear (r2 = 0.9694), with a very good sensitivity of 49.243 pm/mmHg in the IOP pressure range of 0 to 50 mmHg. Due to its ease of fabricating, simplicity of design, and ability to continuously measure pressure with good repeatability and stability, the proposed sensor thus offers a potential solution for IOP monitoring.

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.

A study of mydriatic effect on intraocular pressure and anterior chamber angle morphology by anterior segment optical coherence tomography

Context Pharmacological mydriasis possibly is associated with intraocular pressure (IOP) rise and anterior chamber angle changes. Hence, this study is focused on pressure analysis with anterior segment optical coherence tomography measurements of angle parameters during various dilation phases. Aims Purpose is to investigate IOP variations during dilation phases and to discover association of anterior segment optical coherence tomography measurements. Settings and design Observational study. Patients and methods Thirty-two participants were recruited and IOP measured by rebound tonometer in pre, mid, and full pupillary dilation phases. Lens vault (LV at horizontal and vertical), angle opening distance (AOD at 500 and 750 μm) and trabecular iris space area (TISA at 500 and 750 μm) in temporal and nasal scans were quantified. Paired t test performed to establish a statistical significance P value less than or equal to 0.05. Statistical analysis used MS Excel. Results A total of 32 participants with mean age of 47.5±10.94 years consisting of 17 (53.13%) males and 15 (46.87%) females with 20 (62.5%) right and 12 (37.5%) left eyes were investigated. Mean IOP in pre, mid, and full-dilation phases were 14.86±2.87, 15.94±2.72, and 15.63±2.69 mmHg. Predilation IOP with IOP in mid and full dilation showed statistical significance (P=0.0001, 95% confidence interval 0.56–1.56) and 0.88 and 0.85 Pearson’s coefficients, respectively. IOP analysis with LV, AOD, and TISA in pre, mid, and full-dilation phases exhibited a significant difference (P&lt;0.0001). Conclusion This research highlights an increase in IOP alongside a noteworthy decrease in the average LV by 30.94 μm during mid-dilation compared to the predilation phase. Likewise, the AOD at 750 μm demonstrated a significant reduction by 0.40 and 0.45 μm in temporal scans during mid and full dilation, respectively, while TISA remained unchanged.

Systemic and ocular pressure changes following sympathetic activation in yoga practitioners - A comparative study

Introduction and Aim: Blood Pressure (BP), Intraocular Pressure (IOP) and Ocular Perfusion Pressure (OPP) are precursor parameters that lead to development of glaucoma. Under conditions of stress, either physical or psychological origin, there is disturbance of autonomic regulation. This causes increased activation of the sympathetic nervous system which might influence BP and ocular pressures. An altered autonomic balance towards lower sympathetic drive is observed in subjects practicing yoga, but it is not clear whether this adaptation also influences ocular pressures. Our study attempted to analyze variations in BP, IOP and OPP following sympathetic activation in yogic practitioners and non-practitioners of yoga. Materials and Methods: One hundred and ten subjects aged 18 - 25 years were recruited and categorised into yoga and non-yoga group. Basal BP was recorded using a sphygmomanometer and IOP was recorded using a rebound tonometer. Isometric hand grip (IHG) and Cold pressor test (CPT) were administered one at a time. IOP and BP were recorded immediately following these sympathetic activation tests. Mean arterial pressure and OPP was calculated using standard formula. Results: Significant increase in the values of pulse, BP, IOP and OPP following sympathetic activation were observed in the non-yoga group which was not noted in the yoga group. Elevation in systemic and ocular pressures following sympathetic activation was less in yoga practitioners. This adrenergic response was greater in the non-yoga group. Conclusion: Regular yoga practice maintains adequate perfusion of ocular tissues by autoregulation. Hence yoga can be recommended as a complementary health approach for the autonomic nervous system imbalance.

Deep Learning-Based Identification of Intraocular Pressure-Associated Genes Influencing Trabecular Meshwork Cell Morphology

Genome-wide association studies have recently uncovered many loci associated with variation in intraocular pressure (IOP). Artificial intelligence (AI) can be used to interrogate the effect of specific genetic knockouts on the morphology of trabecular meshwork cells (TMCs) and thus, IOP regulation. Experimental study. Primary TMCs collected from human donors. Sixty-two genes at 55 loci associated with IOP variation were knocked out in primary TMC lines. All cells underwent high-throughput microscopy imaging after being stained with a 5-channel fluorescent cell staining protocol. A convolutional neural network was trained to distinguish between gene knockout and normal control cell images. The area under the receiver operator curve (AUC) metric was used to quantify morphological variation in gene knockouts to identify potential pathological perturbations. Degree of morphological variation as measured by deep learning algorithm accuracy of differentiation from normal controls. Cells where LTBP2 or BCAS3 had been perturbed demonstrated the greatest morphological variation from normal TMCs (AUC 0.851, standard deviation [SD] 0.030; and AUC 0.845, SD 0.020, respectively). Of 7 multigene loci, 5 had statistically significant differences in AUC (P<0.05) between genes, allowing for pathological gene prioritization. The mitochondrial channel most frequently showed the greatest degree of morphological variation (33.9% of cell lines). We demonstrate a robust method for functionally interrogating genome-wide association signals using high-throughput microscopy and AI. Genetic variations inducing marked morphological variation can be readily identified, allowing for the gene-based dissection of loci associated with complex traits. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Design and development of a noninvasive ocular pressure estimator.

A snapshot intraocular pressure (IOP) is ineffective in identifying the IOP peak and fluctuation, especially during sleep. Because IOP variability plays a significant role in the progression of glaucoma, monitoring the IOP, especially during sleep, is essential to capture the dynamic nature of IOP. We aimed to design an ocular pressure estimator (OPE) that can reliably and accurately measure the IOP noninvasively over closed-eyelid condition. Ocular pressure estimator works on the principle that the external pressure applied by raising the IOP of the eyeball is transmitted through a compressible septum to the pressure sensor, thus recording the IOP. A fluid-filled pouch with a pressure sensor was placed over a rubber glove mimicking the eyelid (septum), covering the cornea of enucleated goat eyeballs. A pressure-controlled setup was connected to a goat cadaver eye, which was validated by a rebound tonometer. Cannulation of eyeballs through the lower limbus had the least difference from the control setup values documented using rebound tonometer, compared with cannulation through the optic nerve. Intraocular pressures ranging from 3 to 30 mmHg was induced, and the outputs recorded using OPE were amplified and recorded for 10 minutes (n = 10 eyes). We stratified the randomization of the number of times and the induced pressures. The measurements recorded were found to be linear when measured against an IOP range of 3 to 30 mmHg. The device has excellent reliability (intraclass correlation coefficient, 0.998). The repeatability coefficient and coefficient of variations were 4.24 (3.60 to 4.87) and 8.61% (7.33 to 9.90), respectively. The overall mean difference ± SD between induced IOP and the OPE was 0.22 ± 3.50 (95% confidence interval, -0.35 to 0.79) mmHg across all IOP ranges. Ocular pressure estimator offers a promising approach for reliably and accurately measuring IOP and its fluctuation noninvasively under a condition mimicking a closed eye.

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 first-in-human pilot study of a novel electrically-passive metamaterial-inspired resonator-based ocular sensor embedded contact lens monitoring intraocular pressure fluctuations

Glaucoma is a leading cause of blindness with no cure, but early treatment and effective monitoring can often slow the progression of the disease. Monitoring of glaucoma is based on the measurement of intra-ocular pressure (IOP) that is a physiological parameter related to the mechanical state and parameters of the eye. Conventionally, diagnosing and assessing the progression of glaucoma is based on the method of measuring IOP discretely at clinics. Recent studies have demonstrated the importance of continuously monitoring IOP for 24 h to elucidate the effect of circadian rhythm. In this work, a metamaterial-inspired electrically-passive sensor-embedded contact lens is presented to monitor the IOP fluctuations based on a first-in-human pilot study. The sensor inside the contact lens is an electrically passive, metamaterial-based resonator that can be measured using a wearable antenna patch. The system has been tested with six healthy volunteers during an experiment to induce deliberate IOP changes via water-loading and placing the individuals in supine position using a recliner seat. The initial data compared with tonometer measurements suggest that the system can be used to assess the variation of IOP continuously.

Characterization of intraocular pressure variability in conscious rats

Elevation of mean intraocular pressure (IOP) has long been recognized as a leading risk factor for glaucoma. Less is known about the possible contribution of moment-to-moment variations in IOP to disease development and progression due to limitations of tonometry, the prevailing method of IOP measurement. Tonometry provides good estimates of mean IOP but not IOP variance. The aim of this study was to quantitatively characterize IOP variability via round-the-clock IOP telemetry in conscious unrestrained rats. The anterior chamber of one eye was implanted with a microcannula connected to a wireless backpack telemetry system, and IOP data were collected every 4 s for one week. The cannula was then repositioned under the conjunctiva, and control data were collected for an additional week. IOP statistics were computed in 30-min intervals over a 24-h period and averaged across days. All animals exhibited a diurnal variation in mean IOP, while deviations about the mean were independent of time of day. Correlation analysis of the deviations revealed transient and sustained components, which were respectively extracted from IOP records using an event detection algorithm. The amplitude and interval distributions of transient and sustained events were characterized, and their energy content was estimated based on outflow tissue resistance of rat eyes. Transient IOP events occurred ∼231 times per day and were typically ≤5 mmHg in amplitude and 2–8 min in duration, while sustained IOP events occurred ∼16 times per day and were typically ≤5 mmHg in amplitude and 20–60 min in duration. Both persisted but were greatly reduced in control recordings, implying minor contamination of IOP data by motion-induced telemetry noise. Sustained events were also often synchronous across implanted animals, indicating that they were driven by autonomic startle and stress responses or other physiological processes activated by sensory signals in the animal housing environment. Not surprisingly, the total daily fluidic energy applied to resistive outflow pathways was determined primarily by basal IOP level. Nevertheless, transient and sustained fluctuations collectively contributed 6% and diurnal fluctuations contributed 9% to daily IOP energy. It is therefore important to consider the cumulative impact of biomechanical stress that IOP fluctuations apply over time to ocular tissues.

Dry Eye Para-Inflammation Treatment: Evaluation of a Novel Tear Substitute Containing Hyaluronic Acid and Low-Dose Hydrocortisone.

Purpose: The purpose of this study was to check the efficacy and safety of a novel tear substitute containing hyaluronic acid and low-dose hydrocortisone in the treatment of moderate dry eye disease. Methods: In this prospective randomized study, 38 patients with moderate dry eye disease were divided into two treatment groups: Group 1 received one drop of 0.2% sodium hyaluronate and 0.001% hydrocortisone four times daily for 3 months, while Group 2 received 0.15% sodium hyaluronate and 3% trehalose at the same dosage. OSDI and SANDE questionnaires, Non-Invasive Break-Up time (NIBUT), Tear Meniscus Height (TMH), meibography, Lipid Layer Thickness (LLT), Tear Break-Up Time (TBUT), Corneal Staining Score (CFS), and Intraocular Pressure (IOP) were evaluated at baseline and after 1, 2, and 3 months of treatment. Results: During the treatment period, Group 1 showed statistically significant improvement in OSDI score (p = 0.002), SANDE score (p = 0.01), NIBUT (p < 0.0001), LLT (p < 0.0001), TBUT (p = 0.01), and CFS (p = 0.02). In Group 2, significant improvement was observed only in the TBUT score (p < 0.05). Comparison of the two groups showed that NIBUT and LLT were significantly different at the end of treatment (p = 0.001 for both comparisons), with more favorable results for sodium hyaluronate and hydrocortisone than for sodium hyaluronate and trehalose. No significant variations in intraocular pressure were observed in either group during the treatment period (p > 0.05). Conclusions: The study confirms that a 3-months treatment with hyaluronic acid 0.2% in combination with low-dose hydrocortisone 0.001% improves the signs and symptoms of moderate DED and that a low-dosage 0.001% hydrocortisone can be helpful in preventing the progression to chronic stages of DED.

Association Between Days of the Week and Intraocular Pressure: Japan Ningen Dock Study.

The analysis of intraocular pressure (IOP) by day of the week using the mega database showed a periodic weekly pattern with the highest value on Monday. To evaluate IOP by the day of the week. Annual health checkup examinees between April 2014 and March 2015 were cross-sectionally evaluated. As a result, 655,818 participants [51.5±10.5 (range: 20-96) years, 40.1% women] from 103 medical centers were included. IOP was measured using a noncontact tonometer. The mean IOPs of each day of the week were compared using multiple comparison test and multiple linear regression analysis. Wednesday was set as the reference. Moreover, weekly IOP variations stratified by sex and age were also evaluated. Mean IOPs from Monday to Sunday were 13.19±2.97, 13.06±2.92, 13.05±2.91, 13.05±2.92, 13.12±2.94, 13.10±2.96, and 13.16±2.78mmHg. IOP was significantly higher on Monday, Friday, and Saturday than those on Wednesday ( P <0.001, <0.001, 0.002). After adjusting for factors affecting IOP, the IOPs on Monday and Saturday were higher than those on Wednesday [β=0.097 (95% CI: 0.074-0.121), P <0.001; β=0.032 (95% CI: 0.005-0.059), P =0.019]. Men had significantly higher IOPs on Monday and Saturday than on Wednesday [β=0.142 (95% CI: 0.110-0.173), P <0.001; β=0.053 (95% CI: 0.017-0.089), P =0.004], whereas women did not have a significant trend. Participants aged below 65 years had higher IOPs on Monday ( P <0.001 in under 60 years; P =0.003 in 60-64 years), while those aged 65 years or older did not ( P =0.856). IOP values may have a periodic weekly pattern. The high IOP on Monday was more pronounced in men aged less than 65 years.

Effect of Repeated Intravitreal Injections in Glaucoma Spectrum Diseases.

To evaluate whether repeated intravitreal injections (IVI) with an anti-vascular endothelial growth factor (anti-VEGF) agent are associated with glaucomatous progression in eyes with glaucoma spectrum diseases (GSD). Single-center, retrospective, longitudinal study of patients with bilateral and similar GSD who: (1) received ≥8 IVI in only one eye during the study period; (2) had ≥2 retinal nerve fiber layer thickness (RNFL) measurements obtained by spectral-domain optical coherence tomography (SD-OCT) at least 12 months apart. The primary outcome was the absolute RNFL thickness change, comparing injected and fellow uninjected eyes. Linear mixed effects models were constructed, including a multivariable model. Sixty-eight eyes from 34 patients were included, 34 injected and 34 fellow uninjected eyes. Average baseline age was 67.68±21.77 years with a follow-up of 3.66±1.89 years and 25.12±14.49 IVI. RNFL thickness decreased significantly from 80.92±15.78 to 77.20±17.35 μm (p<0.001; -1.18±1.93 μm/year) in injected eyes and from 79.95±17.91 to 76.61±17.97 μm (p<0.001; -1.07±0.98 μm/year) in uninjected eyes. In a multivariable linear mixed model of injected eyes, only higher baseline RNFL thickness (p < 0.001) significantly predicted higher absolute RNFL thickness loss. Neither absolute RNFL thickness variation (p=0.716) nor RNFL rate (p=0.779) was significantly different between paired injected and uninjected eyes. Absolute IOP variation was not significantly different between groups (16.62±4.77 to 15.09±4.34 mmHg in injected eyes and 17.68±5.01 to 14.50±3.39 mmHg in fellow uninjected eyes; p=0.248). The proportion of eyes receiving glaucoma medical treatment increased significantly in both groups (55.9% to 76.5% in injected eyes; p=0.039; 58.8% to 76.5% in uninjected eyes; p = 0.031). The number of glaucoma medications also increased significantly in both groups (1.03±1.11 to 1.59±1.18 glaucoma medications in injected eyes; p=0.003; 1.09±1.11 to 1.56±1.19 glaucoma medications in uninjected eyes; p=0.003). Repeated IVI do not seem to accelerate glaucomatous progression. Future studies with a longer follow-up are needed.

VEGF-A-induced changes in distal outflow tract structure and function

PurposeTo investigate changes in distal outflow tract vessels caused by VEGF-A and their impact on outflow.MethodsWe compared VEGF-A perfused porcine anterior segments with and without trabecular meshwork (TM) to control eyes. In the first experiment (n=48), we analyzed live changes of the outflow tract with spectral-domain optical coherence tomography (SD-OCT) over 3 h and reconstructed them in 3D. In a second experiment (n=32), we measured the intraocular pressure (IOP) variation in response to VEGF-A over 48 h and computed the outflow facility.ResultsVEGF-A increased the vessel volume of the distal outflow tract by 16.8±10.6% while control eyes remained unchanged (0.5±6.8%). Volume changes occurred within the first 100 min before plateauing at 140 min. VEGF-A enhanced the outflow facility in eyes without TM by 38.6±25.5% at 24 h as compared to controls (p<0.05).ConclusionVEGF-A dilated vessels of the distal outflow tract and increased the outflow facility even after TM removal, pointing to a regulatory mechanism independent of proximal structures.

Twenty-Four-Hour Intraocular Pressure Pattern In Glaucoma Suspects in an African Population.

Twenty-four-hour intraocular pressure measurement (Phasing) among glaucoma suspects showed higher intraocular pressure (IOP), greater fluctuation, and more varying peak times occurring mostly outside clinic hours, between 12 midnight and 8 am in 68.9% of them. To characterise 24-hour variation in IOP, in glaucoma suspects and normal individuals in an African population. A cross-sectional analytical study was carried out between March and October 2019 at the University of Ilorin Teaching Hospital. A total of 204 study participants, comprising 102 primary open angle glaucoma (POAG) suspects and 102 age and sex-matched controls with healthy eyes were recruited. Participants had a comprehensive ophthalmic examination. Measurements of IOP were taken every 2 hours during a 24-hour period using an iCare tonometer. The mean age was 43.64±14.02 SD and 43.02±13.55 SD ( P =1.000) for POAG suspects and controls, respectively. The mean peak IOP was significantly higher in POAG suspects (21.87± 4.65mmHg) compared with controls (17.17± 2.32mmHg) ( P <0.001). Whereas, the mean trough IOP reading was not significantly different between the 2 groups. In both groups of participants, the peak and trough IOP in the majority were recorded outside of clinic hours. The majority (68.9%) of POAG suspects had a peak IOP between midnight and 8 am, whereas the control group peaked mostly at 4 pm (16.7%) and 4 am (41.7%). Twenty-four-hour IOP variation was 6mmHg or less in 73.6% of control eyes, while in the POAG suspects, 83.3% of eyes had variation greater than 6mmHg. Compared with age and sex-matched healthy controls, glaucoma suspects of African descent showed significantly higher mean IOP and IOP variation, with most peak IOP detected outside of clinic hours.

Intraocular Pressure Changes While Reading Smartphone Digital Text Versus Printed Text in Healthy Individuals and those with Glaucoma.

Reading results in a rise in intraocular pressure (IOP) which is greater while using smartphones compared with printed text among healthy and individuals with medically controlled primary open angle glaucoma (POAG). To compare the effect of reading for 30 minutes using smartphone and printed text on IOP. Sixty healthy volunteers and 22 patients with medically controlled POAG were asked to perform reading tasks using printed text followed by digital (smartphone) text under standardized conditions. IOP assessment was done using a rebound tonometer at baseline and subsequently at 10, 20, and 30 minutes of reading and 10 and 20 minutes post completion of reading tasks. IOP variations from baseline were measured and compared. Paired and independent ' T ' test analysis was performed to study IOP variations, and a P -value <0.05 was considered statistically significant. The mean baseline IOP among volunteers and patients withPOAG was 14.58 (±2.91) and 15.02 (±2.18) mmHg, respectively. There was a rise in IOP in all participants with reading using either of the modalities, which normalized after 20 minutes of cessation. There was a statistically significant difference in rise in IOP from baseline between the 2 modalities (printed text reading and smartphone reading) at 20 minutes {+0.78 & +2.01 ( P =0.002)} and 30 minutes {+0.64 & +1.72 ( P =0.004)} among healthy volunteers and at 20 minutes {+0.78 & +2.01 ( P =0.002)} among POAG patients. Reading is associated with the rise in IOP in both healthy volunteers and POAG individuals. The IOP rise is more marked with smartphone compared with printed text reading.

Intraocular Pressure Variations in Postural Changes: Comparison between Obese and Non-Obese Controls.

Comparing intraocular pressure (IOP) changes (ΔIOP) between obese subjects and non-obese controls in relation to different positions: standing, sitting, supine. the IOP was measured in both obese patients and non-obese controls groups with Tono-Pen AVIA in different positions following this sequence: after 5 min (5') in the standing position, sitting, supine, supine after 5 min (supine 5') and immediately after standing. ΔIOP values obtained comparing all positions were, therefore, evaluated. 92 eyes of 46 obese subjects aged between 18 and 59 years (mean 38.07 ± 11.51 years) and of a Body Mass Index (BMI) between 31.84 and 60.65 (mean 41.84 ± 7.05) were evaluated. A total of 48 eyes of 24 non-obese controls aged between 23 and 55 (mean 35.21 ± 11.96 years) and of a BMI between 18.20 and 26.79 (mean 21.04 ± 2.36) were also recruited. In obese subjects, there were statistically significant differences between the IOP in the supine position and the supine positions 5' with all other IOP measurements (p < 0.05). There were statistically significant differences between ΔIOP in both supine positions and prolonged standing positions obtained by obese subjects and non-obese controls (p < 0.05). In obese subjects, there is a statistically significant increase in IOP in the supine positions that is significantly greater than the non-obese population. BMI is weakly correlated with IOP and ΔIOP in postural changes.

Intraocular Pressure Values using IcareⓇ Rebound Tonometer and Correlation with Postconceptional Age in Premature Infants.

This study aimedto determine a normative range of intraocular pressure (IOP) values measured with Icare rebound tonometer in premature infants and evaluate IOP variation over time and its correlation with the progression of postconceptional age (PCA). By doing so, we also evaluated advantages of this IOP-measuring method in this population when compared to more traditional methods. We conducted a single-center prospective study that included premature infants (gestational age 32 weeks) who were admitted to the neonatal intensive care unit (NICU) in Hospital Professor Doutor Fernando Fonseca. The study took place between January and December 2021. IOP was measured using Icare tonometer on the occasion of the first retinopathy of prematurity (ROP) screening requested by the NICU and again after a two-week interval if PCA was still 37 weeks. IOP measurements were stopped at 37 weeks or if the infant was discharged. The evaluated outcomes were mean IOP values and their correlation with PCA. Thirty-four eyes of 17 preterm infants with a mean gestational age of 29.4 2.3 weeks and a mean birth weight of 1222.9 361.9 gr were evaluated. The mean IOP registered was 16.1 6.4 mmHg, with a median value of 15.3 mmHg. The top 90 percentile was 22.1 mmHg and the bottom 10 percentile was 9.0 mmHg. The average IOP reduction was 4.8 6.7 mmHg (P = 0.0019) within the two-week interval of PCA. The mean IOP in premature infants was 16.1 6.4 mmHg and this value significantly decreased by 4.8 6.7 mmHg every two weeks of PCA.

The necessity of pretreatment with 0.1% pranoprofen for femtosecond-assisted cataract surgery: A single-center, randomized controlled trial

PurposeTo explore the effect of the variation of pupil diameter (PD) and intraocular pressure (IOP) induced by femtosecond laser treatment on the subsequent phacoemulsfication and intraocular lens implantation. And whether the application of 0.1% pranoprofen could significantly reduce the miosis and increased IOP caused by femtosecond laser treatment in femtosecond laser-assisted cataract surgery (FLACS). MethodsIn this study, patients were pretreated with (trial group) or without (control group) topical 0.1% pranoprofen. The PD and IOP were measured at different time points within 30 ​min after the completion of the femtosecond laser treatment. ResultsThe comparisons of the two groups showed the PD of patients pretreated with 0.1% pranoprofen was significantly larger than that of the control only at 15 ​min after FLACS (P ​= ​0.046), and there was no significant difference in IOP at any time point (P ​> ​0.05). Neither the ratio of significant miosis (PD ​≤ ​5 ​mm) nor intraocular hypertension (IOP ≥30 ​mmHg) was significantly different between the control group (1.72%, 6.67%) and the trial group (1%, 4.17%) (P ​> ​0.05). ConclusionsThe PD and IOP of patients undergoing FLACS showed fluctuations within a small range. The rates of significant miosis and intraocular hypertension are very low, it is safe for surgeons to complete the follow-up procedures within 30 ​min after femtosecond laser treatment. Pretreatment with 0.1% pranoprofen exerted a slight, albeit significant prophylactic effect preventing pupil miosis. However, it provided only a limited benefit in patients undergoing FLACS without other complications.

Assessment of quality of life in glaucoma patients in a tertiary care center in Eastern India.

The aim of this study is to assess the quality of life (QOL) in glaucoma patients and find out the sociodemographic factors predicting QOL. A cross-sectional study was conducted in a tertiary care center from August 2021 to February 2022. Subjects diagnosed with glaucoma for at least 6 months were enrolled. After taking informed consent, demographic details and detailed history were collected for all patients. Comprehensive eye examination (visual acuity, intraocular pressure, gonioscopy, fundoscopy, visual field assessment, ocular coherence tomogram assessment) was done for all and they were asked to fill the WHOQOL-BREF questionnaire. Data were collected and analyzed using SPSS 21. One hundred and ninety-nine patients were recruited. Mean age of participants was 57.99 ± 10.76 years. Based on various domains and subgroups, QOL values were significant with respect to income (P = 0.016). Gender-wise QOL in females was lower than that of males with respect to all the domains (P = 0.001). While marital status affected both environmental and social domain, literacy affected only the social domain. A variation in intraocular pressure affected the QOL in the psychological domain. QOL was not significantly associated with the severity of the disease. Gender was the most predominant predictor out of all sociodemographic factors. Chronic diseases affect the QOL of individuals in many ways. Glaucoma being a chronic disease hampers patients' vision irreversibly and by extension the various physical, social, and psychological aspects of the patient's life as well. Hence, knowledge of the change in QOL it brings about can help plan the treatment, counseling, and management of these patients.

Experimental evidence to understand mechanical causes of retinal detachment following blunt trauma

PurposeThis study aimed to perform an in vitro experiment to simulate retinal detachment caused by blunt impact, and provide experimental evidence to understand mechanical causes of traumatic retinal detachment. MethodsThe experiment was conducted on twenty-two fresh porcine eyes using a bespoke pendulum testing device at two energy levels (0.1J for low energy and 1.0J for high energy). We examined dynamic forces and mechanical responses to the impact, including global deformations, intraocular pressure changes and the energy absorption. Another set of twenty-two eyes underwent pathological examination immediately after being subjected to blunt impact. Twelve additional intact eyes were examined as controls. All pathological sections were scored to indicate whether retinal detachment had occurred. ResultsA dynamic variation in intraocular pressure was detected following impact and exhibited an approximate sinusoidal oscillation-attenuation profile. The peaks of impact force were 12.9 ± 1.9 N at low-energy level and 34.8 ± 9.8 N at high-energy level, showing a significant difference (p < 0.001). The positive and negative peaks of intraocular pressure were 149.4 ± 18.9 kPa and −10.9 ± 7.2 kPa at low-energy level, and 274.5 ± 55.2 kPa and −35.7 ± 23.7 kPa at high-energy level, showing significant differences (p < 0.001 for both levels). Retinal detachments were observed in damaged eyes while few detachments were found in control eyes. The occurrence rate of retinal detachment differed significantly (p < 0.05) between the high- and low-energy impact groups. ConclusionsThis study provided experimental evidence that shockwaves produced by blunt trauma break the force equilibrium and lead to the oscillation and negative pressure, which mainly contribute to traumatic retinal detachment.