Intraocular Pressure Research Articles

Clinical analysis of supraciliary effusion development following gonioscopy-assisted transluminal trabeculotomy surgery for pseudoexfoliation glaucoma.

To investigate clinical characteristics of postoperative supraciliary effusion (SCE) development following gonioscopy-assisted transluminal trabeculotomy (GATT) in patients with pseudoexfoliation glaucoma (PEXG). In this prospective and observational study, 64 eyes (64 patients) with PEXG were examined with spectral-domain optical coherence tomography (SD-OCT) after GATT over a 12-month follow-up. Outcomes were surgical success, intraocular pressure (IOP), best-corrected visual acuity (BCVA), number of antiglaucoma medications (AGM) and complications of the SCE (+) group with those of SCE (-) group. SCE was observed in 39 eyes (60.9%) within the first postoperative week. Probability of complete success was significantly higher in the SCE (+) group than in the SCE (-) group (25.6% vs. 16.0%, p = 0.009). IOP was significantly lower at postoperative first day in the SCE (+) group than in the SCE (-) group (p = 0.04), but it was similar thereafter during follow-up (p > 0.05). Postoperative BCVA did not show significant difference at the end of the follow-up (p > 0.05). Postoperative number of AGM was found to be significantly lower in the SCE (+) group compared to the SCE (-) group (p < 0.05). A significant IOP rise was observed after SCE resolution (p = 0.002). Presence of SCE accompanied with significantly lower IOP during the early postoperative period after GATT surgery for PEXG. SCE might have a favourable impact on postoperative AGM use. SCE can easily be examined by SD-OCT, and be used as a prognostic indicator.

Primary Congenital Glaucoma presenting with Acute Corneal Hydrops: a challenging approach to amblyopia prevention

Introduction: Acute hydrops is a rare initial manifestation of Primary Congenital Glaucoma (PCG). It can result in significant corneal opacity, posing an additional risk for amblyopia development in PCG patients. We report a case of a newborn with PCG presenting with acute corneal hydrops and significant corneal scarring, discussing the management and challenges of amblyopia prevention. Case Presentation: A 3-day-old female newborn was referred to our department due to bilateral corneal clouding. Anterior segment examination revealed bilateral corneal edema, with severe corneal prolapse in the right eye consistent with acute hydrops. The anterior chamber structures of the right eye were indiscernible due to significant corneal edema. The left eye presented a deep, quiet anterior chamber with no dysgenesis of anterior segment structures. Intraocular pressure (IOP) measurements were &gt;40 mmHg in both eyes. Corneal diameters were 10 mm OD and 12 mm OS. Fundoscopic posterior segment assessment was not possible due to unclear media. B-scan ultrasonography revealed no significant changes. The patient underwent urgent bilateral trabeculotomy. Postoperatively, intense mechanical stretching induced by severely increased IOP was visible, with the right cornea exhibiting a central opacity managed with topical corticosteroids and showing improvement. Right corneal opacity spared the superior cornea, and atropine drops combined with left eye occlusion were employed to mitigate right eye deprivation amblyopia. Eighteen months later, the patient can fixate and follow objects with the right eye. Left eye corneal transparency was restored, and bilateral IOP control was achieved. Conclusion: Despite prompt surgical treatment, acute hydrops presents a postoperative management challenge and may result in irreversible corneal scarring. Timely management of corneal opacities is crucial to prevent amblyopia. A multidisciplinary approach is essential for the best visual outcome.

Evaluation of retinal and choroidal microvascular alteration after ICL V4c implantation based on OCTA.

To evaluate the changes of retinal and choroidal microvascular including the superficial retinal capillary plexus (SCP), deep retinal capillary plexus (DCP), choriocapillaris (CC), and central retinal thickness (CRT) in high myopic eyes after the implantable collamer lens with a central hole (ICL V4c) implantation using optical coherence tomography angiography (OCTA). This retrospective study included 30 eyes of 30 patients (14 males and 16 females) who underwent ICL V4c implantation in Tianjin Aier Eye Hospital from October 2022 to May 2023. Uncorrected distant visual acuity (UDVA), best corrected distance visual acuity (BDVA), intraocular pressure (IOP), spherical equivalent (SE), axial length (AL), and optical coherence tomography angiography (OCTA) were measured and assessed before surgery, and 1 week, 1 month, and 3 months after surgery. OCTA was used to image and measure several key indicators: the foveal avascular zone (FAZ), vascular density (VD) of the SCP and DCP, blood flow density (BD) of the CC, and CRT. All measurement data were obtained utilizing the instrument's proprietary software, ensuring accuracy and consistency. UDVA were significant improvements at the 1 week, 1 month, and 3 months after ICL V4c implantation surgery. BDVA, FAZ, and CRT maintained stable, however, IOP was higher at 1 week and 3 months post-operation compared to 1-month post-operation. The statistically significant difference was identified within the S3, S7, and S9 of SCP at each time point before and after the surgery (P1 = 0.004; P2 = 0.014; P3 = 0.037). However, paired analyses showed that there was a significant decrease in VD of S3 at 1 week after ICL V4c implantation surgery (P<0.05), which then returned to preoperative levels by 1 month (P>0.05), and the increase in VD of the S7 region at 1 month after ICL V4c implantation, which is significant compared to 1 week post-surgery, but not compared to preoperative levels. An overall comparison of the BD of the CC (2mm) at each time point showed a statistically significant difference (P = 0.029). ICL V4c implantation offers a safe and efficient therapy to the high myopic patients. However, the retinal and choroidal microvascular changes need to be paid attention to in post-ICL implantation patients.

Efficacy of Sutureless Scleral Fixation of One-Piece T-Shaped Haptic Intraocular Lens in Maintaining Anterior Chamber Stability During Descemet Membrane Endothelial Keratoplasty in Vitrectomized Eyes: Leak Test and Iris Diaphragm Reconstruction

Objectives: This study aimed to describe the outcomes of a staged procedure combining Descemet membrane endothelial keratoplasty (DMEK) and sutureless scleral fixation (SSF) of a one-piece intraocular lens (IOL) in a case series. Co-performing endothelial keratoplasty (EK) and SSF is associated with intraoperative and postoperative complications such as graft deployment difficulties, air migration, graft detachment, and IOL opacification or tilt, all of which are evaluated in this study. Methods: This is a retrospective observational case series. Clinical data were collected from eight eyes of eight patients who underwent DMEK for endothelial failure and had previously received an SSF with one-piece IOL following complete vitrectomy. During DMEK surgery, an air leak test was conducted to check for air migration into the posterior chamber. If instability was detected, pupilloplasty was performed. Intraoperative and postoperative data, including DMEK graft unfolding time, were collected. Corrected Distance Visual Acuity (CDVA), refraction, endothelial cell density (ECD), central corneal thickness (CCT), intraocular pressure (IOP), and complications were recorded over a 12-month follow-up period. Results: We performed pupilloplasty in four patients (50%). The median CDVA improved from preoperative 0.85 logMAR (range: 0.60 to 1.00) at baseline to 0.18 logMAR (range: 0.10 to 0.70, p = 0.012) at 12 months. The median refraction value changed significantly from −1.00 to −0.50 at 12 months. The median percentage reduction in ECD after 12 months was 33.4% (range 30 to 40). The median baseline CCT was 689 μm (range: 651 to 701) at baseline visit and 541.5 μm (range: 525 to 591, p = 0.008) at 12 months. The median IOP was reduced significantly during follow-up. The median graft unfolding time was 6 min (5 to 9). One patient required rebubbling for partial detachment on postoperative day one. No complications occurred within 12 months. Conclusions: The effective compartmentalization of the anterior and posterior chambers in vitrectomized eyes with an SSF one-piece IOL and pupilloplasty can facilitate critical steps of DMEK surgery in complex eyes. Additionally, the air leak test could prove useful in identifying the need for iris-lens diaphragm reconstruction.

Retinal Vein Anastomoses in a Patient with Persistent High Intraocular Pressure.

Retinal Vein Anastomoses in a Patient with Persistent High Intraocular Pressure.

Efficacy of XEN gel stent implantation combined with mitomycin C injection in the treatment of open-angle glaucoma: a meta-analysis

ObjectiveTo assess the efficacy of XEN gel stent implantation combined with mitomycin C (MMC) injection in controlling intraocular pressure (IOP) and the dosage of postoperative medication for open-angle glaucoma (OAG) patients.MethodsThe PubMed, Embase, Cochrane Library, and Science Direct databases were searched from inception to August 2022 without any language restriction. All studies that compared IOP and the dose of medication before and after XEN gel stent implantation and MMC injection for OAG patients were included. Data extraction and methodological quality evaluation were performed.ResultsA total of 26 studies (2329 eyes) were involved in meta-analysis. It was revealed that IOP at 1 month after XEN implantation was significantly lower than preoperative IOP [group 1, IOP between 19.2 and 21.2 mmHg: mean difference (MD) = 7.60, 95% confidence interval (CI) [6.55, 8.66], I2 = 0%, P < 0.01; group 2, IOP between 21.6 and 22.8 mmHg: MD = 5.83, 95% CI [4.94, 6.71], I2 = 0%; group 3, IOP between 23.5 and 24.3 mmHg: MD = 9.22, 95% CI [8.33, 10.10], I2 = 0%; group 4, IOP between 24.4 and 26.2 mmHg: MD = 11.64, 95% CI [10.49, 12.80], I2 = 0%)]. Moreover, IOP at 3 months after XEN implantation was also significantly lower than preoperative IOP (MD = 8.31, 95% CI [2.54, 8.46], Z = 13.92, P < 0.00001). IOP at 6 months after XEN implantation was significantly lower than preoperative IOP, and no heterogeneity was found between two groups (group 1, IOP between 17.8 and 21.8 mmHg: MD = 5.71, 95% CI: [5.05, 6.36], I2 = 0%, P < 0.01); group 2, IOP between 22.1 and 23.9 mmHg: MD = 7.92, 95% CI [7.15, 8.70], I2 = 0%, P < 0.01). Low heterogeneity was noted in one group (group 3, IOP between 24.3 and 26.2 mmHg: MD = 9.32, 95% CI [8.66, 9.97], I2 = 30%). It was found that IOP at 12 months after XEN implantation was significantly lower than preoperative IOP (MD = 8.11, 95% CI [7.09, 9.12], Z = 15.68, P < 0.00001). There was high heterogeneity among the different baseline IOP groups at 24-month post-surgery (CHi2 = 41.74, df = 1, I2 = 97.6%, P < 0.01), while no heterogeneity was identified in two groups (group 1, IOP between 19.2 and 22.1 mmHg: MD = 6.30, 95% CI [5.76, 6.85], I2 = 0%, P < 0.01); group 2, IOP between 22.8 and 23.8 mmHg: MD = 9.11, 95% CI [8.45, 9.77], I2 = 0%). Subgroup analysis indicated that the dosage of medication was significantly reduced at 6 months after XEN implantation (group 1, the amount of medication was 2.3–2.96: MD = 1.90, 95% CI [1.78, 2.02], I2 = 0%, P < 0.01); group 2, the amount of medication was 3.2–3.3: MD = 2.59, 95% CI [2.43, 2.75], I2 = 0%). Furthermore, the dosage of medication at 12 months (MD = 1.96, 95% CI [1.72, 2.21], Z = 15.80, P < 0.01) and 24 months (group 1, the amount of medication was 1.89–2.7: MD = 6.30, 95% CI [5.76, 6.85], I2 = 0%, P < 0.01); group 2, the amount of medication was 2.72–3.07: MD = 9.11, 95% CI [8.45, 9.77], I2 = 0%) after XEN implantation was significantly lower compared with the preoperative level.ConclusionXEN implantation combined with MMC injection significantly decreased IOP in OAG patients at 1, 6, 9, 12, and 24 months after treatment. In addition, XEN implantation combined with MMC injection decreased the amount of medication used at 6, 12, and 24 months after treatment in OAG patients.

Progressive Optic Neuropathy in Hydrocephalic Ccdc13 Mutant Mice Caused by Impaired Axoplasmic Transport at the Optic Nerve Head.

Optic nerve head (ONH) atrophy is frequently associated with hydrocephalic conditions. Cerebrospinal fluid (CSF)-containing meninges form a subarachnoid space that terminates at the ONH, which physically impacts it. This study aims to characterize optic neuropathy in congenital hydrocephalic mice with genetic disruption of the Ccdc13 gene. The ccdc13 germline knockout mice were generated. The hydrocephalus phenotype and subarachnoid space surrounding the optic nerve were evaluated using routine histology and Evans blue stain. Optic neuropathy was examined with immunohistochemistry and transmission electron microscopy (TEM). Axon transport was indicated by cholera toxin subunit B (CTB) fluorescence conjugate. Retinal function was evaluated by electroretinography (ERG), and Ccdc13 expression was revealed by a knock-in Gfp reporter. Ccdc13 mutant mice manifested hydrocephalus at birth. ONH displacement, or negative cupping, and enlarged subarachnoid space at the optic terminus occurred as early as 1 month after birth. Intraocular pressure (IOP) was normal. Optic neuropathy was first observed at the ONH, followed by a distal-to-proximal progression of optic nerve pathology indicated by alteration of axonal ultrastructure and deposition of unphosphorylated neurofilament heavy chain. Anterograde axonal transport was also hampered. Retinal ganglion cell (RGC) function was compromised as early as postnatal day 21 (P21), along with reduced neurofilament heavy chain expression. Optic neuropathy caused by disruption of Ccd13 was non-cell autonomous, stemming from hydrocephalus with presumed high intracranial pressure (ICP), which physically impacts the ONH by increasing the translaminar pressure gradient. We provided knowledge of optic neuropathy from a congenital mouse model for hydrocephalus. The hydrocephalus in mice could damage the ONH by increasing the translaminar pressure gradient and negative cupping, leading to impairment in axoplasmic transport and RGC pathology. Our findings highlight the importance of the interplay between IOP and ICP in the development of glaucoma.

Cyclodialysis Cleft After Intravitreal Injection

Introduction: A cyclodialysis cleft, separating the ciliary body muscle from the scleral spur, can cause ocular hypotony by creating an abnormal aqueous humor drainage pathway. Though rare, this can occur post-intravitreal injection. Case presentation: A 53-year-old man with diabetic retinopathy presented with persistent hypotony in his right eye after receiving an aflibercept intravitreal injection. On presentation, his visual acuity was 20/200, and intraocular pressure (IOP) was 2 mmHg. Examination revealed a cyclodialysis cleft in the right eye. Despite initial treatment with steroids and atropine, the hypotony persisted, leading to surgical repair via ab-interno cyclopexy. Post-surgery, IOP normalized, and vision slightly improved. At three months post-operation, IOP was stable at 16 mmHg without glaucoma medication, and no signs of hypotony were present, with vision improving to 20/150. Conclusion: Misplaced intravitreal injections can lead to cyclodialysis cleft formation. Ophthalmologists should be aware of this possible complication. Meticulous gonioscopy and the adjunctive use of ocular imaging are crucial for the proper diagnosis of these cases. Ab-interno direct cyclopexy is an effective surgical approach for cyclodialysis clefts non- responsive to medical or laser treatment.

Safety and efficacy of the Yamane technique for intraocular three-piece lens implantation in Egyptian patients diagnosed with Marfan syndrome: a retrospective study

BackgroundThis study aimed to investigate the safety and efficacy of the Yamane technique (flanged intrascleral haptic fixation with double-needle technique /FIHFT) for three-piece intraocular lens (IOL) implantation in Egyptian patients diagnosed with Marfan syndrome (MFS) presented with subluxated lenses (ectopia lentis, EL).MethodsThis was a retrospective evaluation of thirty-three patients who were diagnosed with MFS and had subluxated lenses in a total of forty eyes. Seven of these patients had bilateral subluxation. Lensectomy or phacoemulsification was performed with limited anterior vitrectomy, followed by IOL implantation using the FIHFT method. Data was collected from medical records, including preoperative and postoperative corrected distant visual acuity (CDVA) using logarithm of the minimal angle of resolution (log MAR), preoperative and postoperative refractions, intraoperative and postoperative complications, and follow-up periods.ResultsThe mean age of patients in the study was 30.79 years, with a mean follow-up of 23.9 months. Post-surgery, the refractive sphere decreased significantly from -9.1 ± 1.4 diopter (D) to -1.4 ± 0.7 D, and cylinder measurements dropped from -4.5 ± 0.8 D to -1.4 ± 0.6 D. The spherical equivalent (SEQ) also declined from -11.4 ± 1.5 D to -2.1 ± 0.8 D. The CDVA improved from 0.80 ± 0.32 to 0.18 ± 0.10 log MAR (P < 0.001). No intraoperative complications were identified. Postoperative complications included IOL decentration (12.5%), vitreous hemorrhage (7.5%), IOL slippage (5%), IOL tilt (5%), and retinal detachment (RD) (5%). Further surgical procedures were necessary for only four cases (10%), all of which had positive outcomes. IOL tilting and slippage occurring at average ages of 18 and 19 years, respectively. No other complications, such as hypotony, elevated intraocular pressure (IOP), corneal edema, iritis, IOL dislocation, cystoid macular edema (CME) or endophthalmitis, were reported.ConclusionsThe Yamane technique has proven effective and safe for treating subluxated lenses in Egyptian patients with Marfan Syndrome, resulting in improved visual acuity with minimal complications, mostly minor and manageable. Comprehensive fundus examinations before and after surgery are essential for promptly identifying retinal breaks and reducing the risk of retinal detachment. IOL tilting and slippage are more common in younger patients.

Flow-Adjusted Trabeculectomy

Background/Objectives: As one of the most efficacious glaucoma surgical techniques, trabeculectomy is considered by many surgeons to be the “gold standard” intra-ocular pressure (IOP)-reducing intervention. The purpose of this study is to present our intra-operative flow-adjusted surgical method, which aims to provide safety and efficacy more simply than previous methods. Methods: Retrospectively, we evaluated outcomes for trabeculectomy or phacotrabeculectomy in surgery-naïve eyes over three years for patients with glaucoma not associated with other ocular co-morbidities. We defined complete success as an IOP between 5 and 18 mmHg plus at least a 20% reduction from baseline, without concomitant medications. Relative success was the same result, with glaucoma medication(s). Failure was regarded as an IOP less than 5 or higher than 18 mmHg, or by the need for a subsequent glaucoma operation. Results: We assessed the results from 186 eyes of 186 patients. After exclusion, a group of 45 trabeculectomies and 35 phacotrabeculectomies were analyzed. In eyes undergoing a trabeculectomy, over a mean follow-up of 16.0 months, IOP fell from 28.1 ± 8.0 mmHg with 3.6 ± 1.1 medications to 9.7 ± 3.6 mmHg (66% reduction) with 0.4 ± 1.0 medications (each p &lt; 0.00001). The success rate was 88.9% (75.6% complete success). In eyes undergoing a phacotrabeculectomy, over a mean of 19.1 months, IOP fell from 26.1 ± 10.2 mmHg with 3.5 ± 1.3 medications to 10.0 ± 3.6 mmHg (62% reduction) on 0.9 ± 1.4 medications (each p &lt; 0.00001). The success rate was 91.4% (57.1% complete success). Complication rates were low, with no major complications in either group. Conclusion: To lower IOP, our intra-operative flow-adjusted trabeculectomy and phacotrabeculectomy techniques appear to be safe and effective.

What intrinsic factors affect the central corneal thickness?

The cornea is one of the tissues responsible for covering and protecting the inner structures of the eye. Central corneal thickness (CCT) is defined as the distance between the anterior epithelial surface and the posterior surface of the endothelial layer. This parameter plays a very important role regarding intraocular pressure (IOP) measurement, evaluation of corneal uniformity, selection of a suitable technique for corneal refractive surgery and the planning of surgical procedures to overcome corneal disease. This comprehensive review elucidates the multifaceted factors influencing the central corneal thickness. Recognising the impact of these factors not only enhances our understanding of corneal dynamics but also contributes significantly to the refinement of diagnostic and therapeutic strategies in ophthalmology.

A Case of Acute Angle Closure Secondary to Pupillary Block Caused by a Dislocated Intraocular Lens-Capsular Tension Ring Complex

A Case of Acute Angle Closure Secondary to Pupillary Block Caused by a Dislocated Intraocular Lens-Capsular Tension Ring Complex

Impaired axonal transport at the optic nerve head contributes to neurodegeneration in a novel Cre-inducible mouse model of myocilin glaucoma.

Elevation of intraocular pressure (IOP) due to trabecular meshwork (TM) dysfunction, leading to neurodegeneration, is the pathological hallmark of primary open-angle glaucoma (POAG). Impaired axonal transport is an early and critical feature of glaucomatous neurodegeneration. However, a robust mouse model that replicates these human POAG features accurately has been lacking. We report the development and characterization of a novel Cre-inducible mouse model expressing a DsRed-tagged Y437H mutant of human myocilin (Tg.CreMYOCY437H). A single intravitreal injection of HAd5-Cre induced selective MYOC expression in the TM, causing TM dysfunction, reducing outflow facility, and progressively elevating IOP in Tg.CreMYOCY437H mice. Sustained IOP elevation resulted in significant retinal ganglion cell (RGC) loss and progressive axonal degeneration in Cre-induced Tg.CreMYOCY437H mice. Notably, impaired anterograde axonal transport was observed at the optic nerve head before RGC degeneration, independent of age, indicating that impaired axonal transport contributes to RGC degeneration in Tg.CreMYOCY437H mice. In contrast, axonal transport remained intact in ocular hypertensive mice injected with microbeads, despite significant RGC loss. Our findings indicate that Cre-inducible Tg.CreMYOCY437H mice replicate all glaucoma phenotypes, providing an ideal model for studying early events of TM dysfunction and neuronal loss in POAG.

Association of glycaemic control with intraocular pressure in a large general population: Results from the UK Biobank.

To evaluate the association of glycated haemoglobin (HbA1c) and serum glucose with intraocular pressure (IOP) in a large UK general population. Participants were selected from the UK Biobank, excluding those with eye conditions that may affect IOP. IOP was measured using an ocular response analyser. Goldmann-correlated IOP (IOPg) and corneal-compensated IOP (IOPcc) were outcomes of interest, and ocular hypertension was defined as left-eye IOPg or IOPcc > 21 mmHg. HbA1c and random (non-fasting) serum glucose were the exposures of interest. Multivariate restricted cubic spline models, as well as linear regression, were applied to explore the associations of interest. Among 68 806 participants (46.5% male), the mean age was 56.7 years. The mean (standard deviation) for IOPg was 15.7 (3.6) mmHg and 15.9 (3.6) mmHg for IOPcc. Occular hypertension was prevalent in 8055 participants (11.7%) and 4178 participants (6.1%) had diabetes. Those with diabetes had higher IOP and a higher prevalence of ocular hypertension. After adjustment for demographic and clinical variables, HbA1c was positively associated with IOP in participants with diabetes, but not in those without diabetes. For every 10-mmol/mol increase in HbA1c, IOPg increased by 0.20 mmHg (95% confidence interval [CI] 0.12, 0.28) and IOPcc by 0.15 mmHg (95% CI 0.07, 0.23); the odds of ocular hypertension was increased by 6% (95% CI 1.00, 1.13) in participants with diabetes. A borderline positive association between serum glucose and IOP was found only in participants without diabetes. Impaired glycaemic control was associated with elevated IOP and a possible risk of ocular hypertension among participants with diabetes but of normal ocular health.

A Comparative Study of the Hand-held IC200 and Slit Lamp-mounted ST500 rebound tonometers with Goldmann Applanation Tonometry

To compare the agreement and repeatability of intraocular pressure (IOP) measured with the slit lamp-mounted ST500 rebound tonometer (iCare Finland Oy, Helsinki, Finland), the hand-held IC200 rebound tonometer (iCare Finland Oy) and Goldmann applanation tonometry (GAT). Cross-sectional study. Glaucoma patients and staff of the Eye Care Centre, Nova Scotia Health, Halifax, Canada. IOP was measured twice each with the IC200, ST500, and GAT. Bland-Altman analysis was used to compare each pair of tonometers and whether the difference between tonometers depended on mean IOP. Intra-class correlation coefficients were also computed. Repeatability of the measurements with each tonometer was assessed by calculating the mean and variance of the difference between the first and second measurement. The relationship between IOP and central corneal thickness was also evaluated. Agreement and repeatability of IOP measurements with the IC200, ST500 and GAT. One eye of 157 participants (64 men and 93 women) with a median (Interquartile range) age and CCT of 62 (45 - 72) years and 553 (533 - 572) μm, respectively, were enrolled. Median IOP with the IC500, ST500 and GAT was 17.1 (14.3 - 21.0), 16.5 (14.0 - 20.8) and 17.0 (14.0 - 20.5) mm Hg, respectively, while the range of IOP (measured with GAT) was 8.5 to 53.0 mm Hg. Measurements with the three tonometers were not statistically different from each other and in neither of the three paired comparisons was the difference in IOP between two tonometers dependent on mean IOP. The ICC values (0.97-0.98) showed excellent agreement between the tonometers. The variance of the difference between the first and second measurements of the ST500 was significantly lower than that of GAT (P = 0.04) and IC200 (P < 0.01). ICCs for intra-tonometer repeatability were also excellent (0.97-0.99). The ST500 shows good agreement with GAT over a large range of IOP, and significantly higher repeatability compared to the IC200 and GAT, suggesting it may be advantageous in clinical settings where topical anesthesia or skilled staff are unavailable.

The Effects of Pregnancy Status on Lacrimal Caruncle Temperature, Intraocular Pressure and Rectal Temperature in Cats: A Preliminary Study.

The objectives of this study were to compare the body temperatures between pregnant and nonpregnant cats from two sites, lacrimal caruncle temperature (LCT) and rectal temperature (RT), and to compare intraocular pressure (IOP) between pregnant and nonpregnant cats. This study was performed on 13 pregnant and 16 anoestrous cats. The gestation period of the pregnant cats ranged from 20 to 45 days. A vaginal smear was also performed to determine the sexual cycles of nonpregnant cats. The IOP was measured using a rebound tonometer. The pregnant cats (38 ± 0.7°C) exhibited a lower RT than the nonpregnant cats (38.5 ± 0.5°C) (p < 0.05). No significant differences existed between the pregnant and nonpregnant groups in the right (R)-LCT or left (L)-LCT (p > 0.05). The average LCT temperature measured 32.30 ± 2.23°C in cats. The right (R)-IOP in pregnant cats (17.69 ± 5.6mm Hg) was significantly lower than in nonpregnant cats (22.37 ± 5.27mm Hg) (p < 0.029). Pregnant cats exhibited a significantly lower left (L)-IOP value (17.69 ± 5.76mm Hg) compared to nonpregnant cats (23.18 ± 5.55mm Hg) (p < 0.015). This study presents a preliminary report that documents a noteworthy reduction in RT in pregnant cats (38 ± 0.7°C) as compared to cats in anoestrus. Pregnancy also has an effect on the IOP. It was hypothesised that the hormonal changes induced by pregnancy in cats would have a substantial impact on IOP and RT. Although body temperature can be measured using LCT, RT should still be utilised as the reference measurement site.

Acute intraoperative fluid misdirection managed with anterior approach irido-zonulo-hyaloido-vitrectomy.

To evaluate the causes of acute fluid misdirection (AFM) and the role of irido-zonulo-hyaloido-vitrectomy (IZHV) in the management of AFM. Among the 95,712 cataract surgeries performed between April 2017 and August 2022 at a tertiary center, six eyes of six patients developed intraoperative AFM and underwent IZHV through the anterior approach. AFM was diagnosed intraoperatively when there was sudden shallowing of the anterior chamber with markedly elevated intraocular pressures (IOPs) not attributable to external causes or choroidal effusion/hemorrhage. The condition resolved with deepening of AC following IZHV. Five eyes had angle closure disease (one of them also had pseudoexfoliation), and one eye had open-angle glaucoma. The mean preop IOP was 25.8 ± 7.3 mmHg, with an IOP range of 18-36. The mean number of preop AGM was 3 ± 1.7. Four eyes developed AFM during combined cataract and trabeculectomy, and two eyes during cataract surgery. Four eyes had aqueous misdirection during or after cortical aspiration, and two eyes after creation of internal trabeculectomy ostium. IZHV was performed for all eyes through an anterior approach using a 23G vitrector, which resulted in instant resolution and deepening of the anterior chamber. The mean follow-up was 8.75 months (1-48 months), the mean postoperative IOP was 16.1 ± 2.6 mmHg, and the mean number of AGM at the last follow-up was 2.8 ± 2.2. The anterior chamber was deep, and IOP was under control in all eyes with four eyes needing AGM. One eye developed postoperative aqueous misdirection due to blockade of the IZHV opening. IZHV can be an effective solution for acute intraoperative AFM, which can be performed via an anterior approach by the anterior segment surgeon.

Amlodipine increases risk of primary open-angle glaucoma

BackgroundThe use of calcium channel blockers is associated with primary open-angle glaucoma (POAG) in a statistically meaningful but minor way. In general, those who had received calcium channel blocker medication were at a 23% increased risk of developing glaucoma in comparison to those who had never taken the antihypertensive drugs. We wished to confirm this association and examine POAG genes that might be involved, since the genetics has not yet been analyzed.MethodsWe used MedWatch and UK Biobank data to evaluate the effects of amlodipine on POAG and intraocular pressure (IOP). We analyzed three POAG-associated single-nucleotide polymorphisms: rs9913911, an intron variant in growth arrest-specific 7 (GAS7), one of the genes that influences IOP; rs944801, an intron variant within CDKN2B-AS1, and rs2093210, an intron variant within SIX6, known to be associated with vertical cup-disc ratio, an important optic nerve head parameter that is often used to define or diagnose glaucoma.ResultsAmlodipine use in MedWatch doubled the prevalence of POAG, from 0.0805 to 0.177%, a small but significant increase. Multivariate analysis by logistic regression of UK Biobank data revealed that POAG risk was significantly increased with age, male sex, major alleles of rs9913911 (GAS7) and rs944801 (CDKN2B-AS1), and minor allele of rs2093210 (SIX6). Amlodipine increased POAG risk by 16.1% (P = 0.032). Amlodipine has not been associated with increased IOP. We confirmed this lack of association and in addition found that GAS7, associated with IOP, was not associated with POAG risk and amlodipine. But CDKN2B-AS1 and SIX6, POAG genes not associated with IOP, were associated with POAG and amlodipine.ConclusionsAmlodipine, a frequently prescribed drug and first line treatment for hypertension, has a potentially hazardous relationship with POAG. Knowledge of this link can guide the prescribing of alternate drugs for hypertensive individuals who have glaucoma or are at risk for it. Diuretics and β-blockers are not associated with POAG or increased IOP and could be substituted for amlodipine in hypertensive patients at risk POAG.Trial registrationNone.Graphical

Comparative Analysis of Central Corneal Thickness in Ocular Hypertension and Healthy Individuals.

This study aimed to compare the central corneal thickness (CCT) between patients with ocular hypertension (OHT) and healthy individuals, and to investigate the relationship between CCT and intraocular pressure (IOP), diopter, and corneal endothelium cell count (CECC). The CCT of 30 healthy subjects and 38 patients with OHT was measured using a non-contact specular microscope. IOP, diopter, and CECC were also assessed for all participants. Comparative analysis of CCT between the two groups was performed, along with correlation analysis between CCT and each parameter. The average CCT for all participants was 527.57 ± 35.84 µm. The average CCT was 516.07 ± 34.76 µm for healthy subjects and 536.66 ± 34.46 µm for patients with ocular hypertension, showing a significant difference between the two groups (P ≤ 0.05). CCT was not correlated with age (Pearson r = -0.098, P = 0.426), diopter (spherical equivalent refraction) (Pearson r = -0.158, P = 0.197), or corneal endothelium cell count (Pearson r = 0.065, P = 0.598). However, a positive correlation was found between ocular hypertension and central corneal thickness (Pearson r = 0.278, P = 0.022). Patients with ocular hypertension of members of the Chinese Han population exhibited greater CCT compared to healthy subjects in this study. CCT showed no association with age, diopter, or corneal endothelium cell count; however, a positive correlation was observed between intraocular pressure and CCT. With CCT as the abscissa and IOP as the ordinate, the linear regression equation is Y=0.05+0.021X (F = 5.508, P = 0.022). The use of non-contact tonometers for measuring CCT may impact the accuracy of diagnosing and treating glaucoma and ocular hypertension.

In vivo lacrimal gland imaging artefact assessment based on swept-source optical coherence tomography for dry eye disease.

This study aimed to characterise imaging artefacts in the lacrimal gland using swept-source optical coherence tomography (SS-OCT) in patients with dry eye disease (DED) and healthy participants and identify risk factors for these artefacts. In total, 151 eyes, including 104 from patients with DED and 47 from non-DED participants, were analysed. Demographic data collection, comprehensive ocular examinations and SS-OCT imaging of the palpebral lobe of the lacrimal gland were performed. Artefacts were classified into distinct categories with different severities. Univariate and multivariate logistic regression analyses were performed to evaluate the association of age, gender, best-corrected visual acuity, intraocular pressure (IOP) and the presence of DED with the presence of artefacts. Eight artefact types and severity grading were defined by analysing 1208 lacrimal SS-OCT images. The three most prevalent artefacts were defocus (75.83%), cliff (67.47%) and Z-off (58.44%). The presence of artefacts was significantly associated with the presence of DED (OR=9.13; 95% CI, 2.39 to 34.88; p=0.001) and higher IOP (OR=1.34; 95% CI, 1.14 to 1.58; p<0.001). Furthermore, multivariate logistic analyses showed that lower tear film breakup time (OR=0.71; 95% CI, 0.55 to 0.92; p=0.009) and higher meibum quality score (OR=2.86; 95% CI, 1.49 to 5.48; p=0.002) were significantly associated with higher odds for the presence of artefacts. DED eyes had more SS-OCT image artefacts than normal eyes. Stringent standardised image quality control should be implemented before further image analysis when using SS-OCT to assess lacrimal gland image.