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ABSTRACT Purpose: This study aimed to compare the safety and effectiveness of intraocular pressure reduction between micropulse transscleral cyclophotocoagulation and "slow cook" transscleral cyclophotocoagulation in patients with refractory primary open-angle glaucoma. Methods: We included patients with primary open angle glaucoma with at least 12 months of follow-up. We collected and analyzed data on the preoperative characteristics and postoperative outcomes. The primary outcomes were a reduction of ≥20% of the baseline value (criterion A) and/or intraocular pressure between 6 and 21 mmHg (criterion B). Results: We included 128 eyes with primary open-angle glaucoma. The preoperative mean intraocular pressure was 25.53 ± 6.40 and 35.02 ± 12.57 mmHg in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups, respectively (p<0.001). The mean intraocular pressure was reduced significantly to 14.33 ± 3.40 and 15.37 ± 5.85 mmHg in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups at the last follow-up, respectively (p=0.110). The mean intraocular pressure reduction at 12 months was 11.20 ± 11.46 and 19.65 ± 13.22 mmHg in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups, respectively (p<0.001). The median preoperative logMAR visual acuity was 0.52 ± 0.69 and 1.75 ± 1.04 in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups, respectively (p<0.001). The mean visual acuity variation was −0.10 ± 0.35 and −0.074 ± 0.16 in the micropulse- and "slow cook" transscleral cyclophotocoagulation, respectively (p=0.510). Preoperatively, the mean eye drops were 3.44 ± 1.38 and 2.89 ± 0.68 drugs in the micropulse- and "slow cook" transscleral cyclophotocoagulation groups, respectively (p=0.017), but those were 2.06 ± 1.42 and 1.02 ± 1.46 at the end of the study in the "slow cook" and micropulse transscleral cyclophotocoagulation groups, respectively (p<0.001). The success of criterion A was not significant between both groups. Compared with 11 eyes (17.74%) in the "slow cook" transscleral cyclophotocoagulation group, 19 eyes (28.78%) in the micropulse transscleral cyclophotocoagulation group showed complete success (p=0.171). For criterion B, 28 (42.42%) and 2 eyes (3.22%) showed complete success after micropulse- and "slow cook" transscleral cyclophotocoagulation, respectively (p<0.001). Conclusion: Both techniques reduced intraocular pressure effectively.

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ABSTRACT Purpose: This study aimed to determine whether early-stage intraocular pressure can be modulated using a thermal face mask. Methods: In this prospective clinical study, healthy participants were randomized on a 1:1:1 allocation ratio to three mask groups: hypothermic (G1), normothermic (G2), and hyperthermic (G3). After randomization, 108 eyes from 108 participants were submitted to clinical evaluations, including measurement of initial intraocular pressure (T1). The thermal mask was then applied for 10 minutes, followed by a second evaluation of intraocular pressure (T2) and assessment of any side effects. Results: The hypothermic group (G1) showed a significant reduction in mean intraocular pressure between T1 (16.97 ± 2.59 mmHg) and T2 (14.97 ± 2.44 mmHg) (p<0.001). G2 showed no significant pressure difference between T1 (16.50 ± 2.55 mmHg) and T2 (17.00 ± 2.29 mmHg) (p=0.054). G3 showed a significant increase in pressure from T1 (16.53 ± 2.69 mmHg) to T2 (18.58 ± 2.95 mmHg) (p<0.001). At T1, there was no difference between the three study groups (p=0.823), but at T2, the mean values of G3 were significantly higher than those of G1 and G2 (p<0.00). Conclusion: Temperature was shown to significantly modify intraocular pressure. Thermal masks allow the application of temperature in a controlled, reproducible manner. Further studies are needed to assess the duration of these effects and whether they are reproducible in patients with pathologies that affect intraocular pressure.

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ABSTRACT Purpose: This study investigated the relationship between blood pressure and intraocular pressure in treatmentnaive, non-glaucoma patients with different blood pressure statuses, focusing on the 24-h ocular volume and nocturnal blood pressure decline. Methods: Treatment-naive, non-glaucoma patients undergoing hypertension evaluation were enrolled as study participants. Simultaneous 24-h ambulatory blood pressure measurement and 24-h ocular volume recording with a contact lens sensor. We also compared ocular volume curve parameters between normotensive and hypertensive patients, as well as between those with and without nocturnal blood pressure decline. Results: A total of 21 patients, including 7 normotensive and 14 treatment-naive hypertensive individuals, were included in the study. of them, 11 were dippers and 10 were non-dippers. No significant difference in the 24-h ocular volume slope was observed between the hypertensive and normotensive patients (p=0.284). However, dippers had a significantly higher 24-h ocular volume slope (p=0.004) and nocturnal contact lens sensor output (p=0.041) than non-dippers. Conclusion: Nocturnal blood pressure decline, rather than the blood pressure level, is associated with the increased 24-h ocular volume slope and nocturnal ocular volume. Further studies are required to determine whether the acceleration of glaucoma progression in dippers is primarily due to low blood pressure, high intraocular pressure, or a combination of both.

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OBJECTIVE: To determine whether novel pre- and postsurgical ultrasound biomicroscopy (UBM) measurements of the canine ciliary cleft (CC) are associated with postoperative ocular hypertension (POH) following cataract surgery and to explore the relationship between intraocular pressure and CC UBM measurements. METHODS: Following pharmacologic mydriasis, UBM images were obtained from 31 client-owned dogs before elective cataract surgery, immediately postsurgery, and 4 to 6 hours following surgery or while experiencing POH ≥ 25 mm Hg. Presurgery and the pre- to postsurgery change in CC measurements were assessed for association with POH using individual mixed-effects logistic regression models and forward variable selection models. Linear mixed-effects models were used to evaluate the relationship of intraocular pressure to UBM measurements within the same eye across multiple time points. RESULTS: Presurgical measurements were not predictive of POH development. An increase in pectinate ligament distance and CC area from presurgical baseline to immediate postsurgical measurement was associated with reduced odds of developing POH, while increasing CC length (from apex to mid point on the pectinate ligament) from pre- to postsurgery and immature cataracts was associated with increased odds of POH. CONCLUSIONs: The change in CC morphology following cataract surgery appears more impactful in the development of POH than individual variations in presurgery CC measurements. Several changes in the CC dimensions following surgery appear associated with POH risk. CLINICAL RELEVANCE: This understanding of a potential mechanism of POH development opens new avenues for researching preventative measures associated with modifying surgical techniques to influence CC morphology following cataract surgery.

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INTRODUCTION:  Previous studies have shown that isolated eyelid myokymia (EM) is usually caused by stress, fatigue, and caffeine consumption. The purpose of this study was to evaluate the association between EM and digital screen time, uncorrected refractive error, intraocular pressure (IOP), and blood electrolyte levels. METHODS: Between February 2023 and June 2024, 103 eyes of 103 patients who applied to the ophthalmology outpatient clinic with complaints of eyelid twitching lasting for more than two weeks and 103 eyes of 103 healthy individuals as a control group were included in the study. All participants were asked to record their daily time spent with digital screens for two weeks. Cycloplegic refractive error, IOP, optic nerve head cup/disc (C/D) ratio, and blood calcium, sodium, potassium, and magnesium levels were recorded and compared between the two groups. RESULTS: Mean digital screen time was 4.84±1.74 hours in the control group and 6.88±2.01 hours in the EM group. It was found that digital screen time was significantly higher in the EM group compared to the control group (p<0.001). There was a strong positive correlation between the duration of eyelid twitching and the time spent in front of digital screens (p<0.001, r=0.670). There was no significant difference in cycloplegic refractive error, IOP, C/D ratio, and blood electrolyte levels between the two groups (p>0.05). CONCLUSION: Prolonged digital screen time might play a role in the development of EM. On the other hand, no relationship was found between eyelid twitching and uncorrected refractive error, glaucoma, or blood electrolyte levels.

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AIM: To observe early clinical outcome with lens position adjustment following the implantable collamer lens (ICL) surgery. METHODS: Sixty patients were selected for this retrospective study. One eye from each patient received Toric ICL for astigmatism correction, and the other received non-astigmatic ICL surgery using horizontal position. Patients with higher postoperative arch height were selected, and their non-astigmatic eye clinical outcome were observed after ICL surgery at 1wk, 1, and 3mo. The clinical measurements included uncorrected visual acuity (UCVA), intraocular pressure (IOP), refractive state, corneal endothelium cell count, and arch height. Three months later, the ICL in each patient's non-astigmatic eye was adjusted to the vertical from the horizontal position. The results were compared before and 1wk, 1, and 3mo after adjustment. RESULTS: UCVA and IOP were significantly reduced 1wk after position adjustment compared to 1wk after ICL implantation (P<0.05). The patients demonstrated significantly reduced arch height and corneal endothelium cell count 1wk, 1, and 3mo after adjusting position compared to 1wk, 1, and 3mo after ICL implantation (P<0.05). However, there was no significant difference in refraction between 1wk, 1, and 3mo after ICL implantation and position adjustment (P>0.05). CONCLUSION: Early positioning adjustment post-phakic ICL implantation can benefit patients with adjusted arch height or higher IOP. Despite the good clinical effects, the doctors should pay attention to the potential for adverse effects on UCVA and corneal endothelium cells following early position adjustment after posterior chamber phakic ICL implantation.

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BACKGROUND: Intraocular  pressure (IOP) reduction is the approach that is commonly accepted for the control of open-angle glaucoma (OAG). Medical therapy is typically the first-line of treatment. Laser trabeculoplasty (LT) is an alternative therapy; however, whether pharmaco-therapeutic options can be replaced by LT as the first-line is still debatable. METHODS: studies conducted till July 2023 that compared the efficacy of medications and LT for OAG were retrieved from databases such as Embase, PubMed, Cochrane Library, and Web of Science. We completed data extraction for outcomes of interest. The quality of eligible studies was evaluated and random-effects (RE) model was applied for analysis. RESULTS: A total of eighteen trials with 2024 patients were included in the analysis. Overall, there was no statistically significant difference between therapies including laser trabeculoplasty (LT) and drug therapy in terms of successful IOP control (RR:1.30, 95%CI: 0.96, 1.78, P = 0.09, I2 = 96%), and reducing intraocular pressure (IOP) (MD:0.15; 95%CI:-0.55,0.85; P = 0.67, I2 = 62%). A significant reduction in drug therapy need in comparison to the group that received medicine (MD:-1.07; 95%CI;-1.21,-0.93), P < 0.001, with a low heterogeneity level (I2 = 16%). Adverse ocular events were more common in the argon laser group (RR:11.71, 95%CI: 9.93, 23.1; P < 0.001). CONCLUSION: Both LT and topical drug therapy exhibit comparable rates of success and efficacy in reducing intraocular pressure in patients with open-angle glaucoma. Selective LT is considered a safe treatment option with a reduced occurrence of adverse effects on the eyes while eliminating the possible adherence concerns associated with topical medicine and it can be considered a viable initial option for first OAG treatment. KEY MESSAGES: What is known Drug therapy is typically the 1st line of treatment for open-angle glaucoma. Although drugs have been shown to effectively reduce intraocular pressure (IOP), they are associated with a range of ocular and systemic negative effects which contributes to suboptimal adherence to medications. Laser trabeculoplasty (LT) is an alternative therapy; however, whether pharmaco-therapeutic options can be replaced by LT as the first-line is still debatable. What is new In terms of IOP reduction and IOP success rate, LT therapy was comparable in efficacy to drug therapy according to our findings. The safety profile of selective LT was found to be preferable compared to Argon LT.

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INTRODUCTION: To investigate the effects of different reading postures on intraocular pressure (IOP) and near-work-induced transient myopia (NITM) in children with myopia. METHODS: Sixty myopic children were instructed to read a book text placed at 33 cm for 30 min with two different reading postures: head bowed and head upright postures. The participants' IOP and NITM were assessed using a rebound tonometer and an open-field autorefractor. The measurement of IOP was conducted prior to reading, during reading sessions (at 5, 10, 20, and 30-min intervals), and after a 5-min recovery period. RESULTS: For the head bowed posture, the mean baseline IOP was 16.13 ± 2.47 mmHg. A significant rise in IOP was observed after 5 min of reading (17.17 ± 2.97 mmHg; +1.03 ± 2.29 mmHg; p = 0.014). Subsequent measurements revealed a further increase after 20 min (17.87 ± 2.90 mmHg; +1.73 ± 2.58 mmHg; p < 0.001), which continued to persist even after 30 min of reading (17.57 ± 3.46 mmHg; +1.43 ± 2.66 mmHg; p = 0.002). The IOP at different time points measured in the head upright posture did not show any significant difference in comparison to the baseline measurement (all p = 1.000). Compared to reading with the head upright, reading with the head bowed resulted in a greater increase in IOP at each time point (p < 0.05). Furthermore, the NITM was higher for reading with the head bowed than for reading with head upright at 30 min (-0.24 ± 0.53 D vs. -0.12 ± 0.47 D, p = 0.038). CONCLUSION: Reading in a head bowed position resulted in greater increases in IOP and NITM compared to reading in a head upright posture.

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OBJECTIVE: To evaluate whether intracameral tissue plasminogen activator (tPA) injection is effective in regulating posterior capsular opacification (PCO), fibrin formation and intraocular pressure (IOP) after cataract surgery. ANIMAL STUDIED: Prospective study involving 30 eyes of 21 dogs that underwent phacoemulsification. PROCEDURES: Thirty eyes were randomly divided into two groups of 15 eyes (control and tPA groups). Intracameral tPA (25 µg/0.1 mL) was injected into tPA group eyes before corneal incision closure but not into the eyes of the control group. The grades of anterior fibrin formation and PCO were compared based on slit lamp biomicroscope examination at 1 and 2 weeks, 1 month, and 2-3 months postoperatively. IOP was measured using applanation tonometry every 30 min for 4 h immediately after operation and on the following morning. The IOP of the two groups at each time was compared. RESULTS: The grade of anterior fibrin formation and that of PCO were not significantly different between the two groups at any time point (p > .05). However, the IOP of the tPA group was significantly lower than that of the control group at each point on the day of surgery (p < .05). No complications were observed with tPA injection, except for temporary hyphema (for 3 days) in one eye. CONCLUSIONS: Although the intracameral tPA injection did not affect anterior fibrin formation and PCO, it effectively maintained normal IOP immediately after phacoemulsification. Thus, our findings provide valuable insights into the potential benefits of intracameral tPA injection in achieving immediate IOP control after phacoemulsification.

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OBJECTIVE: This study aimed to explore the potential causal relationship between intraocular pressure (IOP) and myopia. METHODS: The study included 3,459 patients who underwent corneal refractive surgery at our institution between 2021 and 2023. Preoperative data on IOP, spherical equivalent (SE), axial length (AL), and corneal thickness (CCT) were collected. The association between IOP and myopia was investigated through rank correlation analysis, and causal inference was examined using Mendelian randomization (MR) methods, including MR-Egger, weighted median, mode-based estimation, simple mode, and inverse variance weighted (IVW) approaches. Utilizing summary statistics from genome-wide association studies (GWAS), IOP was considered as the exposure, with myopia as the outcome variable. IVW method was employed for the primary analysis, supplemented by sensitivity analyses. RESULTS: Cross-sectional analysis revealed a non-significant association between corrected IOP (cIOP) and myopia (r = -0.019, P = 0.12). MR analysis indicated a non-significant genetic causal relationship between cIOP and myopia under the IVW method (OR = 1.001; 95% CI [0.999-1.003], P = 0.22), a finding corroborated in replication samples (OR = 0.98; 95% CI [0.96-1.00], P = 0.099). CONCLUSION: This study did not find a direct causal link between IOP and the development of myopia. These findings challenge the traditional role attributed to IOP in the progression of myopia and highlight the complex, multifactorial process of myopia development. This provides a new perspective on understanding the intricate mechanisms behind myopia progression.

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Our goal was to assess the impact of retrobulbar anaesthesia on ocular pressure and perfusion development and to find out if there were systemic or biometric parameters of patients affecting them in order to understand the effect of retrobulbar anaesthesia better. Methods: Changes in intraocular pressure (IOP) and ocular pulse amplitude (OPA) using a dynamic contour tonometer (DCT) were noted before and after retrobulbar anaesthesia (RBA) in combination with five minutes of oculopression at 40 mmHg in 134 patients. Only results with a quality Q 1-3 were considered for further statistical analysis. Systemic and ophthalmic parameters were noted and their impact was tested using linear regression. Results: IOP decreased from 18.9 ± 7.2 mmHg to 15.4 ± 6.3 mmHg (n = 71, p = 0.001) after first RBA. The dosage of midazolam administered during premedication was found to increase IOP significantly after first RBA (B = 3.75; R2 = 0.38). Ocular pulse amplitude decreased significantly from 3.8 ± 1.7 mmHg to 3.0 ± 1.9 mmHg after first RBA (n = 72, p < 0.001). This change was found to be dependent on the presence of diabetes mellitus (n = 68, p = 0.048). Conclusions: IOP and OPA decrease after RBA and oculopression. Caution is needed with midazolam premedication due to potential IOP increase. Patients with diabetes and pre-existing retinal or optic nerve damage should consider alternative anaesthesia methods, such as eye drops or general anaesthesia, due to the observed decrease in OPA after RBA and oculopression.

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The combination of glaucoma and cataract occurs in 14.6-76% of cases, according to various sources. The goal of surgical treatment for these patients is to improve visual function while simultaneously reducing intraocular pressure. Due to the wide variety of proposed surgical methods, there is no consensus on the optimal management strategy for such patients. PURPOSE: This study evaluates the hypotensive effect and visual function outcomes of combined surgery for complicated cataract and glaucoma using the mesh drain made of digeland the xenocollagen drain. MATERIAL AND METHODS: Patients in Group 1 (n=43; 48.3%) underwent combined cataract and glaucoma surgery with implantation of the digel drainage implant, while patients in Group 2 (n=46; 51.7%) underwent an identical operation with the xenocollagen implant. Preoperative tonometric pressure was 27.2±1.7 and 27.3±1.9 mm Hg; best corrected visual acuity was 0.35±0.21 and 0.33±0.18, respectively. The following surgical technique was employed. At 3.0-4.0 mm from the limbus, an intrascleral tunnel was created using a 2.2 mm sclerotome through the conjunctiva in the anteroposterior direction, exiting into the anterior chamber. Capsulorhexis and phacoaspiration were performed. The scleral tunnel was widened to 3 mm, and the intraocular lens was implanted. Penetrating basal coloboma of the iris was formed. The deep flap of the scleral tunnel was dissected from the flat part of the ciliary body and removed. The digel implant was shaped into a T-configuration, while the xenocollagen implant was used without modification. Each drainage was implanted into the intrascleral tunnel (one end directed into the anterior chamber, the other exiting the scleral tunnel). The conjunctiva was sutured with 10/0 stitches, and the paracenteses were hydrated. RESULTS: Over a 24-month follow-up period, the tonometric intraocular pressure in Groups 1 and 2 was 18.8 and 18.5 mm Hg, respectively, and the best corrected visual acuity was 0.51 and 0.58. CONCLUSION: The use of both drainages in the proposed combined surgery for complicated cataract and glaucoma results in similarly stable hypotensive outcomes and high visual function.

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The 2 most known cannabinoids are Δ9-tetrahydrocannabidiol (THC) and cannabidiol (CBD). Both chemicals are extracted from the cannabis plant but can also be synthetically produced. Δ9-Tetrahydrocannabidiol is extracted from the subspecies of the cannabis plant known as the marijuana plant, which contains a high concentration of THC (0.3% to 30%). Δ9-Tetrahydrocannabidiol is a major psychoactive and intoxicating component of the cannabis plant and is not recommended for use in dogs due to its toxic effect. Cannabidiol is extracted from the subspecies of the cannabis plant known as the hemp plant and must contain less than 0.3% THC. Cannabidiol is a major nonpsychoactive component of the cannabis plant, and its effect has been investigated for epilepsy, neoplasia, and osteoarthritis in dogs. Public interest in the medical use of cannabinoids for various diseases and disorders has grown in the last couple of years. The attention has extended to veterinary medicine, where veterinarians and pet owners are curious about what diseases the nontoxic CBD can be used for to treat companion animals. The use of CBD for ophthalmic diseases has also been investigated due to its anti-inflammatory and neuroprotective effects. Intraocular pressure regulation for glaucoma, corneal diseases (eg, keratitis and corneal pain), uveal diseases (eg, endotoxin-induced uveitis), and retinal/optic nerve head diseases (eg, diabetic retinopathy) are areas where CBD's effect has been investigated in humans and animals. The aim of this review is to give an update on what is known regarding the use of cannabinoids, especially CBD, for ophthalmic diseases in dogs.

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OBJECTIVE: This study aims to provide data on the effects of glucagon-like peptide 1 receptor (GLP-1R) agonists on intraocular pressure (IOP). DESIGN: Retrospective clinical cohort study. SETTING: Multicenter. STUDY POPULATION: 1247 glaucoma surgery and treatment naïve eyes of 626 patients who were initiated on GLP-1R agonists compared to 1083 glaucoma surgery and treatment naïve eyes of 547 patients who were initiated on other oral antidiabetics. OBSERVATION PROCEDURES: The University of California Health Data Warehouse was queried for patients exposed to GLP-1R agonists or other oral antidiabetics. Index date was defined as the date of first exposure to the medication. Eyes with at least one pre-exposure and one post-exposure tonometry record within 365 days of the index date were included in the analysis. Clinical and laboratory data elements were extracted from the database. Eyes were censored from the analysis upon exposure to glaucoma hypotensive medication or glaucoma surgery. ∆IOP was analyzed using a paired t-test. Regression analysis was conducted using generalized estimating equations (GEE) accounting for inter-eye correlation. Sensitivity analyses were performed to assess the robustness of the findings. MAIN OUTCOME MEASURES: Primary outcome measure was ∆IOP after exposure to the medication. RESULTS: The median age of all included subjects was 66.2 years [IQR=18.3]; 607 (51.7%) were female, and 667 (56.9%) were Caucasian. Median pre-exposure IOP, HbA1c, and BMI were 15.2 mmHg [IQR=3.8], 7.5 [IQR=2.4], and 29.8 [IQR=9.4], respectively. 776 individuals (66.1%) had diabetes, with the median number of active oral antidiabetics being 1.0 [IQR=1.0], and 441 (37.5%) being insulin users. Several pre-exposure characteristics significantly differed between the GLP-1R agonist and the control group. The mean ∆IOP was -0.4±2.8 mmHg (paired t-test p<0.001) and -0.2±3.3 mmHg (paired t-test p = 0.297) in the GLP-1R agonist and other antidiabetics groups, respectively. Pre-exposure IOP was the only independent predictor of ΔIOP in multivariable GEE. Sensitivity analyses yielded similar results. CONCLUSIONS: Although GLP-1R agonists were significantly associated with a decrease in IOP in the paired analysis, they were not associated with ΔIOP in multivariable GEE. Moreover, the difference between the ΔIOP in the two groups was small. Future prospective studies following a standardized dose and delivery method may provide further insights.

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OBJECTIVE: The aim of this study was to detect and describe ocular abnormalities in a population of Turkmen horses. ANIMALS STUDIED: A total of 55 Turkmen horses (33 mares and 22 stallions) from one herd were evaluated in this study. PROCEDURE(S): Demographic data (Age, Sex, Coat color) were recorded. All animals underwent complete ophthalmic examination. The Schirmer tear test -I (STT-I) was performed for all horses prior to other diagnostic tests. Neuro-ophthalmic examinations (menace response, dazzle reflex, pupillary light reflex, maze test, and visual tracking) were carried out in different lighting situations (bright and dim lights). Slit lamp biomicroscopy, direct and indirect ophthalmoscopy, fluorescein staining, and tonometry were performed for each horse. RESULTS: The mean (standard deviation) age of horses was 5.7 (4.6) years (range of 1-17 years). In total, 18 horses (32.7%) had ocular-related lesions. Cataract, iris hyperpigmentation and corneal edema were the most identified conditions in the horses of this study. CONCLUSIONS: About one-third of studied horses had at least one ocular abnormality. No ocular abnormalities attributed to the distinct cream/gold coat color were identified, which the Turkmen horse is known for.

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Glaucoma is a leading cause of blindness worldwide and glaucoma patients exhibit an early diffuse loss of retinal sensitivity followed by focal loss of RGCs. Combining some previous published results and some new data, this paper provides our current view on how high IOP (H-IOP) affects the light response sensitivity of a subset of RGCs, the alpha-ganglion cells (αGCs), as well as their presynaptic bipolar cells (DBCs and HBCs) and A2 amacrine cells (AIIACs) in dark-adapted mouse retinas. Our data demonstrate that H-IOP in experimental glaucoma mice significantly decreases light-evoked spike response sensitivity of sONαGCs and sOFFαGCs (i.e., raises thresholds by 1.5-2.5 log units), but not that of the tONαGCs and tOFFαGCs. The sensitivity loss in sONαGCs and sOFFαGCs is mediated by a H-IOP induced suppression of AIIAC response which is caused by a decrease of transmission efficacy of the DBCR→AIIAC synapse. We also provide evidence supporting the hypothesis that BK channels in the A17AC→DBCR feedback synapse are the H-IOP sensor that regulates the DBCR→AIIAC synaptic efficacy, as BK channel blocker IBTX mimics the action of H-IOP. Our results provide useful information for designing strategies for early detection and possible treatments of glaucoma as physiological changes occur before irreversible structural damage.

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PURPOSE: To investigate the relationship between intraocular pressure (IOP) changes and corneal biomechanical properties, determine the quantitative relationship between IOP changes and corneal biomechanical properties in patients with glaucoma and observe the differences among different types of glaucoma when the effects of high-level IOP were excluded. DESIGN: Prospective clinical cohort study. METHODS: Setting: Institutional. PATIENTS: Treatment-naive patients with primary open-angle glaucoma or ocular hypertension (OHT) were included. OBSERVATION PROCEDURES: IOP was measured using a Goldmann applanation tonometer. Corneal biomechanics were evaluated using a corneal indentation device and corneal visualization Scheimpflug technology. Medication therapy was used for IOP reduction. Repeated measurements were taken at the baseline visit and each week thereafter within a month. Paired t tests were used to compare IOP and corneal biomechanical metrics before and after IOP-lowering therapy. One-way analysis of variance was employed to investigate potential differences across groups, with a Bonferroni post hoc correction administered for multiple intergroup comparisons. MAIN OUTCOME MEASURES: Corneal biomechanical parameters following IOP changes. RESULTS: Eighty-one participants (mean age, 41.63 ± 17.33 years) were included in this study. The cohort comprised 20 patients with normal-tension glaucoma (NTG), 47 with high-tension glaucoma (HTG), and 14 with OHT. The baseline corneal stiffness (88.58±18.30 N/m) and corneal modulus (0.71±0.16 MPa) were greater than the post-IOP reduction values (67.15±9.24 N/m and 0.54±0.08 MPa, respectively; P<0.001). The relationships between changes in IOP and changes in corneal biomechanical parameters were Δ corneal stiffness=2.06*ΔIOP+6.47 (P<0.001) and Δ corneal modulus=0.017*ΔIOP+0.051 (P<0.001). After IOP reduction, the mean corneal stiffness at the 4th week in the NTG group was significantly lower (60.97±6.36 N/m) than that in the HTG (67.25±9.01 N/m) and OHT (75.62±6.52 N/m, P < 0.001) groups. Additionally, the stiffness of HTG patients was lower than that of OHT patients (P = 0.003). CONCLUSIONS: Changes in IOP have an impact on corneal biomechanical parameters. Decreases in corneal stiffness and modulus were observed after IOP reduction. When the effect of high-level IOP was excluded, corneal biomechanics varied according to the type of glaucoma. The HTG corneas were softer than the OHT corneas, and the NTG corneas were even softer.

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This initial methods study presents the initial immunohistochemical and transcriptomic changes in the optic nerve head and retina from three research-consented brain-dead organ donors following prolonged and transient intraocular pressure (IOP) elevation. In this initial study, research-consented brain-dead organ donors were exposed to unilateral elevation of IOP for 7.5 h (Donor 1), 30 h (Donor 2), and 1 h (Donor 3) prior to organ procurement. Optic nerve tissue and retinal tissue was obtained following organ procurement for immunohistological and transcriptomic analysis. Optic nerve sections in Donor 1 exposed to 7.5-hours of unilateral sub-ischemic IOP elevation demonstrated higher levels of protein expression of the astrocytic marker, glial fibrillary acidic protein (GFAP), within the lamina cribrosa with greatest expression inferior temporally in the treated eye compared to control. Spatial transcriptomic analysis performed on optic nerve head tissues from Donor 2 exposed to 30 h of unilateral IOP elevation demonstrated differential transcription of mRNA across laminar and scleral regions. Immunohistochemistry of retinal sections from Donor 2 exhibited higher GFAP and IBA1 expression in the treated eye compared with control, but this was not observed in Donor 3, which was exposed to only 1-hour of IOP elevation. While there were no differences in GFAP protein expression in the retina following the 1-hour IOP elevation in Donor 3, there were higher levels of transcription of GFAP in the inner nuclear layer, and CD44 in the retinal ganglion cell layer, indicative of astrocytic and Müller glial reactivity as well as an early inflammatory response, respectively. We found that transcriptomic differences can be observed across treated and control eyes following unilateral elevation of IOP in brain dead organ donors. The continued development of this model affords the unique opportunity to define the acute mechanotranscriptomic response of the optic nerve head, evaluate the injury and repair mechanisms in the retina in response to IOP elevation, and enable correlation of in vivo imaging and functional testing with ex vivo cellular responses for the first time in the living human eye.

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INTRODUCTION: The purpose of this study is to assess the real-life efficacy and tolerance of a new preservative-free, surfactant-free latanoprost (PFSF-LAT) formulation. METHODS: Retrospective, multicentre, non-comparative, observational study in patients with ocular hypertension or open angle glaucoma, naïve or non-naïve to previous intraocular pressure (IOP)-lowering treatment, and treated for at least 3 months with the study eye drop. IOP for worse eye, ocular signs and symptoms, and concomitant use of artificial tears were collected at study drug initiation and at last visit under treatment. Reasons for discontinuing the study eye drop (if relevant) and investigators' satisfaction were also assessed. RESULTS: In the per protocol population (103 eyes; 63 naïve, 39 switched, 1 not classified because of missing data), IOP decreased significantly (p < 0.001) from 21.6 ± 5.0 mmHg at baseline to 16.1 ± 3.5 mmHg at the end of the study (mean reduction of - 5.5 ± 4.6 mmHg; - 25.5%). IOP in naïve patients was significantly improved, with a mean reduction of 7.1 mmHg (- 30.7%), which was within expected latanoprost IOP-lowering effect. Interestingly, in previously treated patients, switching to PFSF-LAT also allowed for a further 2.9 mmHg decrease in IOP (p < 0.001). The incidence of ocular side effects at study initiation was significantly (p < 0.001) reduced from 31.1% to 11.3% in the overall population, and from 65.0% to 7.5% in switched patients. This included conjunctival hyperaemia and superficial punctate keratitis (from 42.5% to 2.5% and from 37.5% to 2.5% in switched patients, respectively). According to investigators, tolerance and efficacy of the study eye drop were satisfactory or very satisfactory in 98.1% and 83.2% of patients, respectively. CONCLUSION: PFSF-LAT is an efficient treatment for patients with glaucoma with an improved tolerance profile. It can be considered as initial therapy in naïve patients or in patients with poor ocular tolerance to previous IOP-lowering eye drops.