Ocular severe involvement in oculofaciocardiodental syndrome: Description of a case series

BACKGROUND

Oculofaciocardiodental (OFCD) syndrome is a rare genetic disorder affecting ocular, facial, dental, and cardiac systems, being an X-linked condition caused by pathogenic variants in the BCL-6 corepressor gene (BCOR). We report a case series of three female patients with OFCD syndrome with severe glaucoma.

RESULTS

Three female patients with OFCD syndrome with different variants involving BCOR gene, in heterozygosity: a seven-years-old girl with an insertion (c.2037_2038dupCT), a nine years-old girl with a microdeletion in the X (p21.2-p11.4)) spanning the BCOR gene; and a 25 years-old female with a deletion (c.3858_3859del). Systemic involvement is variable among patients ranging from one patient mainly with ocular and dental involvement to one with associated intra-auricular and intra-ventricular defects. All the patients presented with congenital cataracts diagnosed in the first days of life. Cataract surgery was performed without incidents between 6 and 16 weeks of age in all the patients. Postoperatively, the three patients developed ocular hypertension and glaucoma with the need for surgical interventions, including trabeculectomy, Ahmed valve implantation, and cyclophotocoagulation.

CONCLUSION

OFCD syndrome characterizes by a severe ocular involvement with glaucoma as a characteristic feature. Ocular hypertension after cataract surgery in these patients is challenging, almost always needing surgery during childhood. Therefore, we consider BCOR disruption may predispose to a higher incidence of glaucoma due to its aggressiveness and early onset on our case series. The awareness of these complications is crucial to an adequate follow-up of the patients.

Real life experience following combined excimer laser trabeculostomy and phacoemulsification in eyes with ocular hypertension or mild glaucoma and cataract

OBJECTIVES

To assess the efficacy and safety of combined phacoemulsification and excimer laser trabeculostomy (ELT) in eyes with cataract and mild controlled glaucoma or ocular hypertension (OHT).

METHODS

Single-centre analysis of eyes that underwent phacoemulsification and ELT between 2017 and 2021. Change in intraocular pressure (IOP), glaucoma medication requirements, corrected distance visual acuity (CDVA), complications and re-interventions were evaluated. Success was defined as a reduction ≥20% from preoperative IOP, an IOP ≤ 14 mmHg or a reduction in glaucoma medication requirements with an IOP equal or lower than the preoperative IOP.

RESULTS

Mean follow-up was 658 ± 64 days. Mean preoperative IOP was 17.76 ± 4.88 mmHg, it decreased to 15.35 ± 3.10 mmHg at 1 year (n = 37) (p = 0.006) and to 14.00 ± 3.78 at 3 years (n = 8) (p = 0.074). Mean number of glaucoma medication requirements decreased from 2.02 ± 1.0 preoperatively to 1.02 ± 0.96 at 1 year (n = 37) (p < 0.001) and to 1.63 ± 0.92 at 3 years (n = 8) (p = 0.197). Complete success was achieved in 17.7% of eyes and qualified success in 54.8%. Two eyes of 2 patients had early postoperative hyphema. Two eyes of 1 patient underwent filtering surgery 2 months after the procedure, and 2 eyes of 1 patient underwent laser trabeculoplasty 3.8 years after the procedure due to uncontrolled IOP.

CONCLUSIONS

Combined phacoemulsification and ELT is effective and safe in eyes with mild glaucoma or OHT and cataract. It significantly reduced IOP and glaucoma medication requirements 1 year after surgery.

Inhibition of NOX4 with GLX351322 alleviates acute ocular hypertension-induced retinal inflammation and injury by suppressing ROS mediated redox-sensitive factors activation

Reactive oxygen species (ROS) overproduction plays an essential role in the etiology of ischemic/hypoxic retinopathy caused by acute glaucoma. NADPH oxidase (NOX) 4 was discovered as one of the main sources of ROS in glaucoma. However, the role and potential mechanisms of NOX4 in acute glaucoma have not been fully elucidated. Therefore, the current study aims to investigate the NOX4 inhibitor GLX351322 that targets NOX4 inhibition in acute ocular hypertension (AOH)-induced retinal ischemia/hypoxia injury in mice. Herein, NOX4 was highly expressed in AOH retinas, particularly the retinal ganglion cell layer (GCL). Importantly, the NOX4 inhibitor GLX351322 reduced ROS overproduction, inhibited inflammatory factor release, suppressed glial cell activation and hyperplasia, inhibited leukocyte infiltration, reduced retinal cell senescence and apoptosis in damaged areas, reduced retinal degeneration and improved retinal function. This neuroprotective effect is at least partially associated with mediated redox-sensitive factor (HIF-1α, NF-κB, and MAPKs) pathways by NOX4-derived ROS overproduction. These results suggest that inhibition of NOX4 with GLX351322 attenuated AOH-induced retinal inflammation, cellular senescence, and apoptosis by inhibiting the activation of the redox-sensitive factor pathway mediated by ROS overproduction, thereby protecting retinal structure and function. Targeted inhibition of NOX4 is expected to be a new idea in the treatment of acute glaucoma.

Complications Occurring Through 5 Years Following Primary Intraocular Lens Implantation for Pediatric Cataract

Importance

Lensectomy with primary intraocular lens (IOL) implantation is often used in the management of nontraumatic pediatric cataract, but long-term data evaluating the association of age and IOL location with the incidence of complications are limited.

Objective

To describe the incidence of complications and additional eye surgeries through 5 years following pediatric lensectomy with primary IOL implantation and association with age at surgery and IOL location.

Design, Setting, and Participants

This prospective cohort study used Pediatric Eye Disease Investigator Group cataract registry data from 61 institution- and community-based practices over 3 years (June 2012 to July 2015). Participants were children younger than 13 years without baseline glaucoma who had primary IOL implantation (345 bilateral and 264 unilateral) for nontraumatic cataract. Data analysis was performed between September 2021 and January 2023.

Exposures

Lensectomy with primary IOL implantation.

Main Outcome and Measures

Five-year cumulative incidence of complications by age at surgery (<2 years, 2 to <4 years, 4 to <7 years, and 7 to <13 years) and by IOL location (sulcus vs capsular bag) were estimated using Cox proportional hazards models.

Results

The cohort included 609 eyes from 491 children (mean [SD] age, 5.6 [3.3] years; 261 [53%] male and 230 [47%] female). Following cataract extraction with primary IOL implantation, a frequent complication was surgery for visual axis opacification (VAO) (cumulative incidence, 32%; 95% CI, 27%-36%). Cumulative incidence was lower with anterior vitrectomy at the time of IOL placement (12%; 95% CI, 8%-16%) vs without (58%; 95% CI, 50%-65%), and the risk of undergoing surgery for VAO was associated with not performing anterior vitrectomy (hazard ratio [HR], 6.19; 95% CI, 3.70-10.34; P < .001). After adjusting for anterior vitrectomy at lens surgery, there were no differences in incidence of surgery for VAO by age at surgery (<2 years, HR, 1.35 [95% CI, 0.63-2.87], 2 to <4 years, HR, 0.86 [95% CI, 0.44-1.68], 4 to <7 years, HR, 1.06 [95% CI, 0.72-1.56]; P = .74) or by capsular bag vs sulcus IOL fixation (HR, 1.22; 95% CI, 0.36-4.17; P = .75). Cumulative incidence of glaucoma plus glaucoma suspect by 5 years was 7% (95% CI, 4%-9%), which did not differ by age after controlling for IOL location and laterality.

Conclusions and Relevance

In this cohort study, a frequent complication following pediatric lensectomy with primary IOL was surgery for VAO, which was associated with primary anterior vitrectomy not being performed but was not associated with age at surgery or IOL location. The risk of glaucoma development across all ages at surgery suggests a need for long-term monitoring.

Laser-Induced Ocular Hypertension in a Mouse Model of Glaucoma

Glaucoma is a neurodegenerative disease that leads to the loss of retinal ganglion cells (RGC) and thus to blindness. There are numerous experimental models used for the study of this pathology. Among the different models, episcleral vein photocoagulation is one of the most widely used. In this model there is a transient increase in intraocular pressure that returns to normal values about 7 days after induction of ocular hypertension (OHT). In addition, typical glaucoma changes, such as loss of RGC, thinning of the optic nerve fiber layer, and glial activation, occur in this model. All these changes have been described in detail over time after OHT induction. In this chapter, we describe the detailed method of OHT induction in Swiss albino mice by diode laser photocoagulation of limbal and episcleral veins.

Silicone Oil-Induced Ocular Hypertension Glaucoma Model (SOHU) in Rodent and Nonhuman Primate

In this chapter, we describe a clinically relevant inducible and reversible ocular hypertension glaucoma model, which mimics the secondary glaucoma that can be a postoperative complication when silicone oil (SO) is used as a tamponade agent in human vitreoretinal surgery. First, we detail the procedures for generating SO-induced ocular hypertension (SOHU) in mouse and describe the two variations of this model that simulate common but distinct glaucoma types. We also describe separately the related procedures for measuring IOP and removing SO to return IOP to normal. Lastly, we describe the extension of the SOHU model in nonhuman primate (NHP), which recapitulates the severe neurodegeneration of acute human glaucoma but with unique dynamic changes of IOP due to the tolerance of the NHP ciliary body. The SOHU glaucoma model is, therefore, suitable for assessing experimental therapies for neuroprotection and regeneration, with or without treatment to lower IOP (SO removal), and consequently for translating relevant findings into novel and effective clinical treatments for glaucoma and other neurodegenerations. This model is straightforward, does not require special equipment or repetitive procedures, closely simulates clinical situations, and may be applicable to diverse animal species although minor modifications may be required.

Optic Disc Drusen in Patients With Ocular Hypertension: A Case Series and Review of the Literature

BACKGROUND

The identification of glaucomatous optic neuropathy in the setting of optic disc drusen (ODD) is a challenge, and the decision of whether to offer treatment in the form of intraocular pressure (IOP) reduction is controversial. Here, we present a series of patients with coexisting ocular hypertension and ODD to evaluate clinical features, treatment options, and progression of optic neuropathy. In addition, a review of the literature on ODD with elevated IOP is provided.

METHODS

Six patients with ODD and a history of ocular hypertension are presented. Components of the examination and imaging modalities used to establish the diagnosis of ODD were recorded and a description of ocular hypertension history, glaucoma testing, and the potential treatment of IOP were also provided.

RESULTS

In this series, 4 of 6 patients with concurrent ocular hypertension and ODD showed progression of optic neuropathy as assessed by visual field or retinal nerve fiber layer thickness. Of the 2 patients who did not show evidence of progression, 1 was treated with IOP-lowering medications and 1 was observed off treatment. Of the 4 patients who showed evidence of progression, all 4 were initially treated with IOP-lowering medications and 2 ultimately went on to have trabeculectomy surgery. In the patients with progressive optic neuropathy, lowering the IOP seemed to halt the progression suggesting there was a pressure-sensitive component.

CONCLUSIONS

Distinguishing changes to the optic nerve, particularly the structural changes at the lamina cribrosa of true glaucomatous optic neuropathy in the setting of ODD, is a challenge. Careful consideration of risk factors including age, presenting features, progression indicators, and management goals is to be accounted for in the decision to offer treatment. We see the presence ODD in the patients with ocular hypertension as an additional risk for progressive changes to the nerve fiber layer and visual field that needs to be considered when determining whether to initiate therapy. Our data suggest that treatment of IOP in the patients with ocular hypertension with ODD and evidence of progression reduces the risk of further progression. Further work is needed to determine whether progression of optic neuropathy in the setting of coexisting ODD and ocular hypertension is related mechanistically to predominantly an ODD-type process, a glaucomatous process, or a combination thereof.

Pro-inflammatory cytokines in aqueous humor from dogs with anterior uveitis and post-operative ocular hypertension following phacoemulsification, primary glaucoma, and normal healthy eyes

Background

The aim of this study was to evaluate the levels of pro-inflammatory cytokines in aqueous humor (AH) from dogs with anterior uveitis and post-operative ocular hypertension (POH) following phacoemulsification, in AH from dogs with primary glaucoma, and in normal healthy eyes with no signs of anterior uveitis or other ocular diseases.

Methods

An exploratory study including 21 samples of AH collected from 15 dogs; post-phacoemulsification with anterior uveitis and POH (‘POH group’, n = 10 samples), primary glaucoma (‘glaucoma group’, n = 6 samples), and normal (‘normal group’, n = 5 samples). Target mass spectrometry via multiple reaction monitoring (MRM-MS) with the Canine Cytokine SpikeMix™ as internal standard was used to measure the pro-inflammatory cytokine levels.

Results

The MRM-MS method measured 15 pro-inflammatory cytokines. Tumor-necrosis-factor-alpha (TNFα) and interleukin-18 (IL-18) levels in AH were different between all three groups (glaucoma>POH>normal) (p = .05, p = .02, respectively). Additionally, IL-6 was higher in the ‘POH group’ compared to the ‘glaucoma group’ (p = .04) and IL-4 was higher in the ‘POH group’ compared to the ‘normal group’ (p = .04). Intraocular pressure (IOP) was positively associated with increased AH levels of IL-18 (Spearman correlation = .64, p = .03).

Conclusions

MRM-MS using the Canine Cytokine SpikeMix™ as an internal standard was established as a method to detect pro-inflammatory cytokine levels in canine AH. The study demonstrated increased levels of IL-4, IL-6, IL-18, and TNFα in AH from canines with POH following phacoemulsification. Primary glaucomatous eyes had the highest levels of IL-18 and TNFα which may indicate that inflammation plays a role in the pathogenesis of primary glaucoma in dogs.

Automated diagnosing primary open-angle glaucoma from fundus image by simulating human's grading with deep learning

Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness worldwide. Although deep learning methods have been proposed to diagnose POAG, it remains challenging to develop a robust and explainable algorithm to automatically facilitate the downstream diagnostic tasks. In this study, we present an automated classification algorithm, GlaucomaNet, to identify POAG using variable fundus photographs from different populations and settings. GlaucomaNet consists of two convolutional neural networks to simulate the human grading process: learning the discriminative features and fusing the features for grading. We evaluated GlaucomaNet on two datasets: Ocular Hypertension Treatment Study (OHTS) participants and the Large-scale Attention-based Glaucoma (LAG) dataset. GlaucomaNet achieved the highest AUC of 0.904 and 0.997 for POAG diagnosis on OHTS and LAG datasets. An ensemble of network architectures further improved diagnostic accuracy. By simulating the human grading process, GlaucomaNet demonstrated high accuracy with increased transparency in POAG diagnosis (comprehensiveness scores of 97% and 36%). These methods also address two well-known challenges in the field: the need for increased image data diversity and relying heavily on perimetry for POAG diagnosis. These results highlight the potential of deep learning to assist and enhance clinical POAG diagnosis. GlaucomaNet is publicly available on https://github.com/bionlplab/GlaucomaNet .

Cataract Surgery Lowers Intraocular Pressure and Medication Use in the Medication Group of the Ocular Hypertension Treatment Study

PURPOSE

To determine the change in intraocular pressure (IOP) and ocular hypotensive medication use after cataract extraction in the Medication Group of the Ocular Hypertension Treatment Study.

DESIGN

Secondary analysis of randomized clinical trial data.

METHODS

We included 92 participants (n = 149 eyes) of the Medication Group of the Ocular Hypertension Treatment Study who underwent cataract surgery in at least 1 eye during the study and 531 participants (n = 1004 eyes) of the Medication Group who did not undergo cataract surgery. We defined the "split date" as the first study visit that cataract surgery was reported for the cataract surgery group and the 15th visit in the control group to equalize the median number of visits. We then compared the 2 groups at visits relative to this split date.

MAIN OUTCOME MEASURES

Difference in preoperative and postoperative IOP, and number of classes of ocular hypotensive medications between the cataract and control group over a 72-month period.

RESULTS

Cataract surgery significantly decreased the number of ocular hypotensive medications at all postoperative visits (mean, -0.4 medications; P ≤ .005) through the 48-month postoperative visit when compared with the control group. At the split date, approximately 23% of eyes were medication free and 41% had a reduced medication burden. Cataract surgery resulted in a decrease in IOP (P < .001), but the difference in IOP between the groups reduced over time and became nonsignificant after 12 months.

CONCLUSIONS

Cataract surgery in patients with ocular hypertension produced sustained reductions in the average number of ocular hypotensive medications and transient reductions in IOP.

Urrets-Zavalia syndrome following cataract surgery in dogs: A case series

Background:

In human medicine, Urrets-Zavalia syndrome (UZS) is a well-recognized but uncommon postoperative complication characterized by a fixed dilated pupil, accompanied by iris atrophy and glaucoma. Although it was originally reported in 1963 after penetrating keratoplasty surgery for keratoconus, it has been associated with various ophthalmic procedures such as cataract surgery. The condition has not been previously published in the veterinary literature.

Case Description:

Three client-owned diabetic dogs that developed UZS´s triad after cataract surgery are described. Despite uneventful phacoemulsification in the six eyes, five developed moderate-to-severe postoperative ocular hypertension. Although intraocular pressure (IOP) spikes were initially controlled, fixed dilated pupils accompanied by iris atrophy and chronic ocular hypertension were seen in the five affected eyes. Aggressive medical and surgical management maintained vision in three of those eyes. In one eye, uncontrolled IOP led to blindness.

Conclusion:

This is the first published description of UZS in dogs, occurring after phacoemulsification. Although no exact, demonstrable causative element could be determined, we believe that should be considered a triggering condition for this syndrome, as it directly affects the ocular blood flow autoregulation and intrinsic uveal tissue integrity. Until the contrary is proved, diabetes mellitus might be considered as a risk factor for developing this syndrome after cataract surgery in dogs.

GLP-1 Receptor Agonist NLY01 Reduces Retinal Inflammation and Neuron Death Secondary to Ocular Hypertension

Glaucoma is the leading cause of irreversible blindness and is characterized by the death of retinal ganglion cells (RGCs). Recent studies have implicated pro-inflammatory microglia, macrophages, and A1 astrocytes in the pathogenesis of neurodegenerative diseases. The role of pro-inflammatory, neurotoxic A1 astrocytes in glaucoma is just beginning to be explored. Using a mouse model of glaucoma, we demonstrate that ocular hypertension is sufficient to trigger production of C1q, interleukin-1α (IL-1α), and tumor necrosis factor α (TNF-α), three cytokines necessary and sufficient to drive the formation of A1 astrocytes. Upregulation of these cytokines occurs first in CD11b+ CD11c+ cells followed by CD11b+ CD11c- cells. Ablation of this pathway, by either genetic deletions of C1qa, IL-1α, and TNF-α, or treatment with glucagon-like peptide-1 receptor agonist NLY01, reduces A1 astrocyte transformation and RGC death. Together, these results highlight a neuroinflammatory mechanism of glaucomatous neurodegeneration that can be therapeutically targeted by NLY01 administration.

Ocular hypertension as a cause of cilioretinal artery obstruction in the young patient, about a case

A 16-year-old patient seen in the Emergency Department due to loss of visual acuity (VA) in the left eye (LE), and oppressive headache of 1 day onset. The patient was on treatment with topical corticosteroids for viral conjunctivitis. The VA was 1.00 in the right eye and 0.05 in LE. The intraocular pressure was 42mmHg in both eyes. In the LE, the funduscopy revealed retinal ischaemic oedema in the papillomacular bundle. The optical coherence tomography angiography (OCT-A) showed an obstruction of the cilioretinal artery. The systemic study was normal, the cardiac and supra-aortic trunks ultrasound was normal, with ocular hypertension secondary to corticosteroids being the only causative agent identified. This case shows that in the event of an obstruction of the cilioretinal artery, a systemic study should be performed in order to identify possible embolic phenomena. Ocular hypertension is one of the possible causes that may be responsible for this condition.

Risk Factors for Early Intraocular Pressure Elevation After Cataract Surgery in a Cohort of United States Veterans

INTRODUCTION

Cataract surgery is the most frequently performed surgery in the Veterans Health Administration (VHA). A well-known complication is a transient but potentially harmful elevation in intraocular pressure (IOP) within the 24-h postoperative period. The purpose of this study is to investigate the risk factors for IOP elevation 1 d after cataract surgery in a cohort of United States (US) veterans.

MATERIALS AND METHODS

The study included 784 patients who underwent cataract surgery between April 2013 and April 2016 at a single Veterans Affairs medical center in Providence, RI. One thousand one hundred thirty-seven cataract surgeries were considered in total. Institutional Review Board (IRB) approval was obtained through the Providence Veterans Affairs Medical Center (PVAMC). Logistic regression, adjusted for patients with bilateral surgeries, was used to evaluate risk factors for first postoperative day IOP elevation (≥28 mmHg). The main outcome measure was elevated IOP on postoperative day 1 (POD1) after cataract surgery.

RESULTS

The average patient age was 74 yr. Ninety-eight percent (1,110/1,137) of cases involved male patients; 75.3% (856/1,137) of the cataract surgeries were performed by resident surgeons. Type II diabetes mellitus (DM) was present in 41% (461/1,137), alpha-1 blocker use in 31% (358/1,137), ocular hypertension (ocular HTN) in 4% (44/1,137), and glaucoma in 11% (126/1,137) of cases. Twenty-two percent (232/1,137) of eyes had elevated IOP. Independent risk factors were a history of ocular HTN (OR: 8.74 [4.03-18.9]), glaucoma (OR: 3.54 [2.17-5.75]), a preoperative IOP ≥22 mmHg (OR: 2.51 [1.12-5.62]), and complicated cataract surgery (OR: 2.45 [1.18-5.08]), defined as vitreous loss, anterior capsular tear (ACT), posterior capsular tear (PCT), or presence of zonular lysis.

CONCLUSION

These findings suggest that cataract surgery patients with ocular HTN, glaucoma, a preoperative IOP ≥22 mmHg, or significant intraocular complications may benefit from prophylactic ocular anti-hypertensive medication.

Postoperative Adverse Events, Interventions, and the Utility of Routine Follow-Up After 23-, 25-, and 27-Gauge Pars Plana Vitrectomy

PURPOSE

To evaluate the utility of standard postoperative visit (POV) intervals in pars plana vitrectomy (PPV) as a function of adverse events (AEs) identified.

DESIGN

Retrospective case review.

METHODS

The medical records of all patients undergoing 23-, 25-, and 27-gauge PPV from January 1, 2016 to December 31, 2016 were reviewed. Each POV was assessed as a standard (s-POV), physicianadjusted (a-POV), or patient-initiated visit (p-POV). Preoperative features, diagnoses, and surgical procedures were evaluated to determine protective and risk factors for AEs.

RESULTS

A total of 256 patients (310 PPVs) were included in this study. The most common cumulative postoperative AEs were elevated intraocular pressure (>30 mm Hg) (12.3%), cystoid macular edema (6.1%), and retinal detachment (5.8%). Patients with the diagnosis of macular hole or epiretinal membrane had the lowest relative risk of AEs [0.30; 95% confidence interval (CI), 0.12-0.75 and 0.36; 95% CI, 0.21-0.63, respectively]. There was no difference in time to AE among different vitrectomy gauge sizes (P = 0.733). Patients in a-POV and p-POV groups had a statistically significant higher incidence of AEs in the POV day 5-10 window (P = 0.004).

CONCLUSIONS

The utility of standard POVs in detecting AEs is dependent on the indication for PPV. Specifically patients undergoing isolated macular surgery (epiretinal membrane peel or macular hole repair) had the lowest relative risk of postoperative AEs and may warrant a less-intensive follow-up regimen.

Obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is increasing in prevalence due to rising obesity. While OSA is a disorder primarily of the upper airway during sleep, its pathophysiological impact on other body systems is increasingly recognised. There has been interest in the prevalence of OSA in different ophthalmic conditions and possible causation has been postulated. As OSA is common, it can be expected that people with co-existent OSA will be found in any ophthalmic disease population studied. To determine with confidence the significance of finding patients with OSA in a particular cohort requires a well matched control group, ideally matched for age, obesity, gender and co-morbidities. Only if one can say with certainty that the prevalence of OSA is higher in a group with a particular co-existent ophthalmic disease can we begin to speculate about possible mechanisms for the overlap in these conditions. Possible mechanisms for how OSA might affect the eye are discussed in this review. The current literature is reviewed with respect to diabetic retinopathy, glaucoma, floppy eyelid syndrome, non-arteritic ischaemic optic neuropathy, keratoconus and AMD. Associations with OSA have been found, but robust prospective studies using multi-channel sleep studies to diagnose OSA are lacking. Gaps remain in the evidence and in our knowledge. It is hoped that this review will highlight the need for ophthalmologists to consider OSA in their patients. It also makes recommendations for future research, especially to consider whether therapies for OSA can also be effective for ophthalmic disorders.

Stato-Kinetic Dissociation in Subjects with Normal and Abnormal Visual Fields

PURPOSE

The aim of the study was to assess the presence and the importance of stato-kinetic dissociation (SKD) in subjects with normal and pathological visual fields (VF).

METHODS

A "customized" perimetric test designed for the assessment of SKD was carried out in seven homogeneous samples of subjects (normal, glaucomatous, ocular hypertensive, retinopathic, cataract, anterior visual pathways neuropathic and posterior visual pathways neuropathic). The results were statistically compared (Anova).

RESULTS AND CONCLUSIONS

SKD is a physiological phenomenon, more evident in the central, paracentral and superior VF, influenced by age and partially by sex. SKD increases in the VF periphery when a posterior visual pathway disorder or retinopathy is present, and decreases in the centro-paracentral VF of glaucomatous and ocular hypertensive eyes. This SKD behaviour should be useful for early diagnosis of glaucoma.

Treatment with Bifemelane for Optic Nerve Damage following High Intraocular Pressure in Rat Eyes

This study found that pretreatment with 4-(o-benzylphenoxy)-N- methylbuty-lamine hydrochloride (bifemelane hydrochloride, Celeport) reduced ischemia-reperfusion injury in rat eyes. Bifemelane (25 mg/kg) was injected intraperitoneally 30 minutes before an ischemic insult, then acute ischemia of the retina and optic disc was induced by increasing intraocular pressure to 110 mmHg for 45 minutes. After one week, the axonal count of the optic nerve was investigated using electron microscopy. The control group consisted of vehicle-treated eyes which received normal saline. The axon count was 93.4 +/- 7.9 for the bifemelane treated group, and 79.2 +/- 6.4 for the controls. The axon count in the treated group was significantly higher. These results suggest that bifemelane, which prevents cerebral nerve cell damage from ischemia, can reduce ischemic retinal nerve cell injury.

Transscleral Suture Fixation and Anterior Chamber Intraocular Lenses Implanted after Removal of Posteriorly Dislocated Crystalline Lenses

The surgical technique is described for simultaneous removal of posteriorly dislocated crystalline lenses and implantation of anterior chamber (AC) or scleral fixation posterior chamber (PC) intraocular lenses (IOL) using pars plana vitrectomy. Twenty-two patients underwent this complex operation. Observation time ranged from 2 to 10 months (mean 5 months). Best-corrected post-operative visual acuity was 1.0 in half the patients in the AC group (n=12), and in 80% of the PC group (n=10). It was less than 0.5 in 25% of cases in the AC group whereas all PC patients had visual acuity 0.5 or better. In nine cases with pre-operative ocular hypertension, post-operative intraocular pressure became normal, although topical glaucoma therapy was necessary in three patients in the AC group and in one from the PC group. No severe complications were found. Removal of posteriorly dislocated crystalline lens using pars plana vitrectomy and limbal incision is a safe procedure. Simultaneous AC or transscleral PC lens implantation is a good alternative to contact lenses. Visual rehabilitation was good in both groups of patients, although post-operative visual acuity was better after PC transscleral fixation than after AC surgery.

A Short Duration Transient Ischemia Induces Apoptosis in Retinal Layers: An Experimental Study in Rabbits

Purpose

To investigate retinal cell apoptosis in an experimental transient, short duration ocular ischemia model.

Methods

An experimental ischemia model, which simulates creating temporary high intraocular pressure to control intraocular bleeding during pars plana vitrectomy, was set up. Rabbits were randomly divided into three groups. Group 1 was the control group. In Group 2, intraocular pressure was increased to 97 mmHg for 5 minutes. In Group 3, intraocular pressure was increased to 97 mmHg for 10 minutes. After 24 hours, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling assay was used to detect retinal apoptosis in rabbit eyes. Only nuclear staining in retinal cells was counted.

Results

Groups with 5 minutes and 10 minutes of ischemia showed significantly higher amount of ganglion cell layer apoptosis when compared with the control group (p<0.05). Light microscopy and standard hematoxylin-eosin did not show any significant damage in the retina cells.

Conclusions

Apoptotic cell death in the retinal cell layers occurs in temporary ischemia-reperfusion as early as 5 and 10 minutes duration.

First Day Review after Uncomplicated Phacoemulsification: Is it Necessary?

PURPOSE

To determine whether first day follow-up is necessary after routine uncomplicated phacoemulsification cataract surgery.

METHODS

Data collected prospectively at day 1 postoperative review.

RESULTS

In 510 consecutive cases, serious complications occurred in 8 (1.6%) (wound leak [4], corneal abrasion [2], iris prolapse [1], hyphema [1]). Intraocular pressure (IOP) >30 mmHg was found in 26 (5.1%) and was strongly associated with a diagnosis of pre-existing glaucoma or ocular hypertension (odds ratio [OR] 7.7). Symptoms of headache or ocular discomfort occurred in 40 (7.8%), mostly in association with raised IOP, and were also associated with pre-existing glaucoma or ocular hypertension (OR 4.7). Central corneal edema was found in 61 (12.0%). In the absence of corneal edema, IOP was >30 mmHg in only two cases (0.39%).

CONCLUSIONS

Few sight-threatening complications were detected on the morning after an uncomplicated procedure. First day follow-up may be safely omitted if adequate patient counseling is undertaken and there is provision of adequate access to eye services. Review prior to discharge on the day of surgery would provide an opportunity to detect these few surgical complications and for counseling. A diagnosis of glaucoma or ocular hypertension is a risk factor for significantly raised next day IOP and these patients are more likely to experience postoperative discomfort. They may benefit from prophylactic treatment.

Ocular Hypertension/Glaucoma in Minipigs: Episcleral Veins Cauterization and Microbead Occlusion Methods

Two methods to induce elevation of the intraocular pressure (experimental glaucoma) are described in the present chapter. The first method is based on increasing the post-trabecular resistance to aqueous outflow by cauterizing the episcleral veins (EVC). This method allows the observation of ultrastructural changes in the trabecular meshwork (TM) without interfering with any structure within the eye such as TM, ciliary body, and/or the Retina. The second method is the multiple injection of microbeads into the anterior chamber, as a pre and intra-trabecular method that induce secondary effects on the TM cells. Both methods lead to an increase in IOP.

High intraocular pressure produces learning and memory impairments in rats

Primary open angle glaucoma (POAG) is a leading cause of irreversible blindness worldwide. Previous MRI studies have revealed that POAG can be associated with alterations in hippocampal function. Thus, the aim of this study was to investigate a relationship between chronic high intraocular pressure (IOP) and hippocampal changes in a rat model. We used behavioural tests to assess learning and memory ability, and additionally investigated the hippocampal expression of pathological amyloid beta (Aβ), phospho-tau, and related pathway proteins. Chronic high IOP impaired learning and memory in rats and concurrently increased Aβ and phospho-tau expression in the hippocampus by altering the activation of different kinase (GSK-3β, BACE1) and phosphatase (PP2A) proteins in the hippocampus. This study provides novel evidence for the relationship between high IOP and hippocampal alterations, especially in the context of learning and memory.

Assessing Precision of Hodapp-Parrish-Anderson Criteria for Staging Early Glaucomatous Damage in an Ocular Hypertension Cohort: A Retrospective Study

PURPOSE

The aims of the study were (1) to stage early glaucomatous field defects following Hodapp-Parrish-Anderson (HPA) criteria in an ocular hypertension (OH) cohort with 7-year follow-up and (2) to recognize the limitation(s) of this staging system.

DESIGN

A retrospective review of subjects with OH.

METHODS

A retrospective review of the visual fields of 183 OH subjects was conducted. A Humphrey Field Analyzer was used for standard automated perimetry in all these participants, tested once every half year for 7 years or until the onset of conversion (study end point). Only nerve fiber bundle glaucomatous abnormalities were identified as per the Ocular Hypertension Treatment Study guideline and considered as converted glaucoma cases from OH. Subsequently, those fields were classified as possible, probable, and definite glaucoma cases following HPA criteria. This study also recognized the limitations of Glaucoma Hemifield Test (GHT) interpretation and the depth and distribution of real scotoma. The criterion for reproducible abnormalities was 3 consecutive abnormal fields with defects in a similar location.

RESULTS

Early glaucomatous defects were identified in 22 patients (27 fields) of 183 OH subjects. Seven of 27 eyes were identified as possible glaucoma, 12 as probable glaucoma, and 8 as definite glaucoma. The GHT was interpreted as within normal limits for 5 cases, borderline for 11 cases, and outside normal limits for 11 cases.

CONCLUSIONS

Hodapp-Parrish-Anderson criteria can recognize subtle nerve damage to diagnose early glaucoma. Visual field abnormalities classified as definite glaucoma cases are less prone to false labeling than normal fields, whereas field defects identified as probable/possible glaucoma may remain underdiagnosed for imprecise GHT interpretations and poor specification of cluster analysis in pattern standard deviation.

[Arterial hypertension and glaucoma: watch out for nocturnal blood pressure]

Glaucoma is the second cause of blindness in industrialized countries. One of the principal risk factors for open angle glaucoma, the most prevalent form of the disease, is an increase in intraocular pressure (IOP). An excessive drop in nocturnal blood pressure (so called dipping) can be harmful by increasing ischemic damage to the optic nerve. In case of progression of glaucoma despite well controlled IOP, 24h BP monitoring is recommended. The relationship between IOP and systemic blood pressure has been the subject of several studies that are reviewed in this article. The influence of antihypertensive drugs on IOP is also discussed.

[Diagnosis and treatment of ocular hypertension]

Ocular hypertension is popular among people, with a prevalence of 3% to 10% in those older than 40 years old. Without proper intervention, over 10% of the patients with ocular hypertension would develop glaucoma in the following 5 to 10 years. Glaucoma has become one of the leading causes of blindness all over the world, which makes it essential for us to pay enough attention to the prevention and treatment of ocular hypertension. However, it is not cost-effective to treat all the patients with ocular hypertension. Certain side effects may also be caused with long-term medical treatment. Therefore, it is of great importance for ophthalmologists to identify the right time and use appropriate therapeutic methods. To introduce the knowledge of ocular hypertension, the definition, epidemiology, diagnosis, risk factors and treatment of ocular hypertension are reviewed in this article. (Chin J Ophthalmol, 2016, 52: 542-546).

Management of Primary Angle-Closure Glaucoma

Primary angle-closure glaucoma (PACG) is a progressive optic nerve degeneration and is defined as a glaucomatous optic neuropathy with associated characteristic enlargement of optic disc cupping and visual field loss that is secondary to ocular hypertension caused by closure of the drainage angle. Angle closure is caused by appositional approximation or adhesion between the iris and the trabecular meshwork. The main treatment strategy for PACG lies in the reduction of intraocular pressure, reopening of the closed angle, and possible prevention of further angle closure. There is no universally agreed best surgical treatment for PACG. Trabeculectomy, goniosynechialysis (GSL), glaucoma implant, and cyclodestructive procedures are effective surgical options. Each of them plays an important role in the management of PACG with its own pros and cons. Accumulating evidence is available to show the effectiveness of visually significant and visually nonsignificant cataract extraction in the treatment of PACG. Trabeculectomy and GSL are often combined with cataract extraction, which may offer additional pressure control benefits to patients with PACG. This review article will discuss laser peripheral iridotomy, argon laser peripheral iridoplasty, and surgeries such as GSL, phacoemulsification, and phaco plus glaucoma surgeries that lower intraocular pressure and also alter the anterior segment and/or drainage angle anatomy. Currently, glaucoma implants and cyclodestruction are mainly reserved for PACG patients who have failed previous filtering operations. Their role as initial surgical treatment for PACG will not be discussed.

One Year of Glaucoma Research in Review-2013 to 2014

PURPOSE

The purpose of this study was to provide the practicing clinical ophthalmologist with an update on relevant glaucoma literature published from 2013 to 2014.

DESIGN

This study is a literature review.

METHODS

The authors conducted a 1-year (October 1, 2013, to September 30, 2014) English-language glaucoma literature search on PubMed of articles containing "glaucoma" or "glaucomatous" with title/abstract as a filter. Medical subject headings filtered searching was not performed because of the newness of the reviewed material.

RESULTS

Literature search yielded 2314 articles, after which we excluded reviews and letters to the editor. We highlighted articles featuring new or updated approaches to the pathophysiology, diagnosis, or treatment of glaucoma and gave preference to human research.

CONCLUSIONS

This review features literature that is of interest to ophthalmologists in practice and also highlights studies that may provide insight on future developments applicable to clinical ophthalmology.

The Rodent Model of Glaucoma and Its Implications

Glaucoma is a group of progressive optic neuropathies, characterized by the degeneration of retinal ganglion cells related to the level of intraocular pressure and other factors. The exact pathogenesis of glaucoma is not known, and current therapeutic options are not sufficient to prevent or recover vision loss in glaucoma patients. Functional, repeatable, and easy-to-use animal models are therefore needed. Because of their inherent advantages, rodent animals, including mice and rats, have been widely developed as models to study various aspects of glaucoma and to evaluate possible novel therapies. However, no single model has been shown to emulate all aspects of glaucoma. In this review, we discuss currently available rodent animal models of glaucoma, their strengths and weaknesses, and the possible implications for current glaucoma research.

[Posture change and intraocular pressure fluctuation]

Although the pathogenesis of glaucoma is complicated and multifactorial, elevated intraocular pressure (IOP) remains the most important known risk factor. The higher the IOP and the larger the IOP fluctuation, the more damage to the optic nerve. IOP fluctuation can be affected by many factors, such as emotion, exercise and circadian rhythm, etc. Recently, the effects of postural change on IOP fluctuation are receiving more and more attention. This article reviews the effects of different body positions on IOP fluctuation, the effects of surgery, medications and aging on posture-induced IOP fluctuation and the effects of postural change on IOP fluctuation of certain special groups. The possible mechanisms of posture-induced IOP fluctuation are also discussed in this article.

[Mechanism study on trans-lamina cribrosa pressure difference correlated with optic neuropathy in glaucoma]

Glaucomatous optic neuropathy is among the most common causes of blindness worldwide. Elevated intraocular pressure (IOP) has long being considered to be the major risk factors for the development and progression of glaucomatous optic nerve damage. However, numerous studies have shown that a relatively large number of patients with typical glaucomatous optic neuropathy, in whom the IOP measurements have always been in the normal range (<21 mmHg, 1 mmHg = 0.133 kPa). Thus, the role of IOP in the pathogenesis of POAG becomes vague and controversial. Based on prospective clinical observations, Beijing iCOP (Intracranial and Intraocular Pressure) Study has found that the orbital cerebrospinal fluid pressure (CSF-P) may be of importance for the physiology and patho-physiology of the optic nerve head and may play a role in the pathogenesis of glaucomatous optic neuropathy. A low CSF-P in the retrobulbar region of the orbit may act as the counter-pressure against IOP and theoretically have a similar effect as an increased IOP on the trans-lamina cribrosa pressure difference which may be more relevant to the glaucomatous optic neuropathy than IOP alone. Moreover, an experimental and chronic reduction in CSF-P in monkeys was associated with the development of optic nerve damage morphologically typical for glaucomatous optic neuropathy. The findings support the hypothesis the CSF-P may play a role in the pathogenesis of glaucomatous optic neuropathy.

Dermatological Side Effects of Brimonidine: A Report of Three Cases

Brimonidine is a potential first line therapy for primary open angle glaucoma (OAG) and ocular hypertension (OHT). It is known to cause various ocular and systemic side effects. Being a newer drug, the whole spectrum of its adverse effects is not known. The dermatological side effects caused by brimonidine have rarely been reported before. We present three OAG patients who presented to us with contact dermatitis of periorbital skin and lichen planus of nail following the use of topical brimonidine (0.2% twice a day) for more than six months. These side effects slowly disappeared on discontinuing the drug but reappeared on reintroducing topical formulation. Such side effects from the use of brimonidine have not been reported before.

Rate of visual field progression in eyes with optic disc hemorrhages in the ocular hypertension treatment study

OBJECTIVE

To compare rates of visual field (VF) change in ocular hypertensive eyes with and without optic dischemorrhage (DH).

METHODS

Ocular Hypertension Treatment Study subjects(minimum 10 reliable VF tests, followed up 5 years) were included. Trend analyses of VF sequences over time of DH and non-DH eyes were assessed by regression of mean deviation (MDR) and pointwise linear regression (PLR). The main outcome measures were rates of VF change in DH and non-DH eyes.

RESULTS

Two thousand six hundred seven eyes (1378 participants) were included. The mean (SD) number of VF tests per eye was 23.7 (4.9) spanning a mean (SD) of 12.2 (2.0) years. At least 1 DH was detected in 187 eyes(7.2%), of which 52 eyes had recurrent DH. Mean deviation rate of change was significantly worse in DH compared with non-DH eyes (mean [SD], −0.17 [0.27] vs−0.07 [0.19] dB/y; P<.01). Significant PLR progression occurred more frequently in eyes with DH (odds ratio,3.6; P<.01), which increased when 2 or more DHs were present (odds ratio, 4.2; P=.01). Eyes initially randomized to treatment were less likely to have a DH during follow-up.

CONCLUSIONS

Eyes with DH had more rapid VF deterioration when assessed by global (MDR) or local (PLR)trend analysis than eyes without DH. Eyes with recurrent DH had similar rates of global VF change (MDR)when compared with eyes with a single DH but reached criteria for rapid PLR change more often. Intraocular pressure reduction in ocular hypertension reduces the risk of developing a DH. Ocular hypertensive eyes with DH should be monitored closely and may need more aggressive therapy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00000125

Autophagy in retinal ganglion cells in a rhesus monkey chronic hypertensive glaucoma model

Primary open angle glaucoma (POAG) is a neurodegenerative disease characterized by physiological intraocular hypertension that causes damage to the retinal ganglion cells (RGCs). In the past, RGC damage in POAG was suggested to have been attributed to RGC apoptosis. However, in the present study, we applied a model closer to human POAG through the use of a chronic hypertensive glaucoma model in rhesus monkeys to investigate whether another mode of progressive cell death, autophagy, was activated in the glaucomatous retinas. First, in the glaucomatous retinas, the levels of LC3B-II, LC3B-II/LC3B-I and Beclin 1 increased as demonstrated by Western blot analyses, whereas early or initial autophagic vacuoles (AVi) and late or degraded autophagic vacuoles (AVd) accumulated in the ganglion cell layer (GCL) and in the inner plexiform layer (IPL) as determined by transmission electron microscopy (TEM) analysis. Second, lysosome activity and autophagosome-lysosomal fusion increased in the RGCs of the glaucomatous retinas, as demonstrated by Western blotting against lysosome associated membrane protein-1 (LAMP1) and double labeling against LC3B and LAMP1. Third, apoptosis was activated in the glaucomatous eyes with increased levels of caspase-3 and cleaved caspase-3 and an increased number of TUNEL-positive RGCs. Our results suggested that autophagy was activated in RGCs in the chronic hypertensive glaucoma model of rhesus monkeys and that autophagy may have potential as a new target for intervention in glaucoma treatment.

Ten-year follow-up of familial nanophthalmos in three siblings

PURPOSE

Nanophthalmos is a rare congenital disorder associated with a high incidence of angle-closure glaucoma. We followed the clinical manifestations of three siblings to evaluate their responses to various treatments.

METHODS

Three sisters with nanophthalmos were followed from 2000 to 2013. Glaucoma and cataract treatments were performed whenever indicated.

RESULTS

The oldest sister had chronic elevation of intraocular pressure (IOP) and underwent laser peripheral iridotomy (LPI) on both eyes, followed by uneventful phacoemulsification with intraocular lens (IOL) implantation on the left eye and phacotrabeculectomy with IOL implantation on the right eye. The middle sister had acute elevation of IOP and initially underwent phacoemulsification combined with implantation of two IOLs on her left eye and LPI on her right eye. Severe uveal effusion occurred when phacoemulsification was performed on her right eye 6 years later, but ultimately was completely resolved. In both sisters, stable IOP and visual results were achieved after lensectomy. The youngest sister, who had suspected angle-closure, achieved a stable IOP and visual results with prophylactic LPI alone.

CONCLUSION

In nanophthalmic eyes, the severity of the disease may foreshadow the severity of surgical complications and responses to therapy.

An internal medicine perspective review of risk factors for assessing and progression of primary open angle glaucoma

Aim of this review was to resume risk factors for the assess and progression of primary open-angle glaucoma (POAG), particularly considering systemic risk factors that can be associated with glaucomatous damage. If intraocular pressure is the main risk factor, we must consider carefully familiarity, age, gender and possible associations with diabetes, hypertension, vascular autoregulation disorders, hypo- and hyperthyroidism, hypo- and hyperadrenalism, sleep apnea syndrome, corticosteroids therapies and other suspected factors cited in literature. Glaucoma's etiology remains unknown, its physiopathology is poorly understood and its diagnosis is often difficult. It is the leading cause of irreversible blindness worldwide and it is the real "silent thief of sight" because the loss of vision often occurs gradually over a long period of time, and symptoms only occur when the disease is quite advanced. Cost-effectiveness analyses for POAG screening are weighted by the degree of uncertainty that glaucoma screening can be effective and reliable achieved. Addressing patients to an ophthalmologic investigation on the basis of the identified risk factors is a fundamental preventing measure.

[Tube versus trabeculectomy study]

Epibulbar glaucoma drainage devices have been only slightly modified since their introduction more than 40 years ago. Having been used primarily in only difficult cases with a poor prognosis (and therefore with poor clinical results) the recently published trabeculectomy versus tube study (TVT) led to a change in our understanding of these devices. In this study epibulbar glaucoma drainage devices (here the Baerveldt device) were employed for early implantation (in some cases as primary glaucoma surgery intervention). Being sceptically monitored the results over the first 5 year clearly showed an almost equal or even better outcome in comparison to trabeculectomy. Despite these good results a critical evaluation seems mandatory mainly because of the unsolved problems concerning late complications. Late tube erosion with subsequent blebitis and enophthalmitis as well as late base plate encapsulation need to be mentioned here. The latter leads to thick fibrous tissue around the base plate resulting in an increase of intraocular pressure (IOP). Late corneal decompensation is also a late complication the pathomechanism of which is only poorly understood. Solving and treating such late complications are often troublesome and time consuming. Future experiments should lead to development of new drainage implant designs and the bulk material should be enhanced and optimized to increase clinical surgical results.

Frequency doubling technology, optical coherence technology and pattern electroretinogram in ocular hypertension

BACKGROUND

To assess which of three methods, namely, optical coherence tomography (OCT), pattern electroretinogram (PERG) or frequency-doubling technology (FDT), is the most sensitive and specific for detecting early glaucomatous damage in ocular hypertension (OH).

METHODS

Fifty-two patients with OH (24 men and 28 women, mean age of 56 ± 9.6 years) with an intraocular pressure (IOP) > 21 mm Hg and fifty-two control patients (25 men and 27 women, mean age of 54.8 ± 10.4 years) with IOP < 21 mm Hg, were assessed. All the patients had normal visual acuity, normal optic disk and normal perimetric indices.All subjects underwent OCT, FDT and PERG. Data were analyzed with unpaired t-tests, Chi-square test and Receiver Operating Characteristic (ROC) curve analyses.

RESULTS

In patients with OH, OCT showed retinal nerve fiber layer (RNFL) thinner than in control group in the superior quadrant (130.16 ± 10.02 vs 135.18 ± 9.27 μm, respectively; p < 0.011) and inferior quadrant (120.14 ± 11.0 vs 132.68 ± 8.03 μm; p < 0.001). FDT showed a significantly higher pattern standard deviation (PSD) (3.46  ± 1.48 vs 1.89 ± 0.7 dB; p < 0.001). With respect to PERG, only the amplitude showed significant differences (p < 0.044) between the two groups. ROC curve analysis revealed a sensitivity and specificity of 92% and 86%, respectively, for FDT-PSD (with an area under the ROC curve of 0.940), whereas with OCT, a sensitivity of 82% and a specificity of 74% was recorded in the inferior RNFL quadrant (with an area under the ROC curve of 0.806) finally with PERG amplitude we found a sensitivity of 52% and specificity of 77% (with an area under the ROC curve of 0.595).

CONCLUSIONS

FDT is the most sensitive and specific method for detecting early glaucomatous damage in eyes with OH, and together with OCT, can be useful in identifying those patients who may develop glaucoma.

TRIAL REGISTRATION

ISRCT number: ISRCTN70295497.

CXCR3 antagonism of SDF-1(5-67) restores trabecular function and prevents retinal neurodegeneration in a rat model of ocular hypertension

Glaucoma, the most common cause of irreversible blindness, is a neuropathy commonly initiated by pathological ocular hypertension due to unknown mechanisms of trabecular meshwork degeneration. Current antiglaucoma therapy does not target the causal trabecular pathology, which may explain why treatment failure is often observed. Here we show that the chemokine CXCL12, its truncated form SDF-1(5-67), and the receptors CXCR4 and CXCR3 are expressed in human glaucomatous trabecular tissue and a human trabecular cell line. SDF-1(5-67) is produced under the control of matrix metallo-proteinases, TNF-α, and TGF-β2, factors known to be involved in glaucoma. CXCL12 protects in vitro trabecular cells from apoptotic death via CXCR4 whereas SDF-1(5-67) induces apoptosis through CXCR3 and caspase activation. Ocular administration of SDF-1(5-67) in the rat increases intraocular pressure. In contrast, administration of a selective CXCR3 antagonist in a rat model of ocular hypertension decreases intraocular pressure, prevents retinal neurodegeneration, and preserves visual function. The protective effect of CXCR3 antagonism is related to restoration of the trabecular function. These data demonstrate that proteolytic cleavage of CXCL12 is involved in trabecular pathophysiology, and that local administration of a selective CXCR3 antagonist may be a beneficial therapeutic strategy for treating ocular hypertension and subsequent retinal degeneration.

Manganese porphyrin reduces retinal injury induced by ocular hypertension in rats

This study aimed to clarify the possible therapeutic benefit of preferential nitric oxide synthase (NOS) inhibition and catalytic antioxidant Mn (III) meso-tetrakis (N-n-hexylpyridinium-2-yl) porphyrin (MnTnHex-2-PyP(5+)) treatment in a rat model of elevated intraocular pressure (EIOP). Rats were randomly divided into different experimental groups which received either intraperitoneal MnTnHex-2-PyP(5+) (0.1 mg/kg/day), intragastric NOS inhibitor (S-methylthiourea: SMT; 5 mg/kg/day) or both agents for a period of 6 weeks. Ocular hypertension was induced by unilaterally cauterizing three episcleral vessels and the unoperated eye served as control. Neuroprotective effects of given treatments were determined via electrophysiological measurements of visual evoked potentials (VEP) while retina and vitreous levels of MnTnHex-2-PyP(5+) were measured via LC-MS/MS. Latencies of all VEP components (P(1), N(1), P(2), N(2), P(3)) were significantly prolonged (p < 0.05) in EIOP and returned to control levels following all three treatment protocols. Ocular hypertension significantly increased retinal protein nitration (p < 0.001) which returned to baseline levels in all treated groups. NOS-2 expression and nitrate/nitrite levels were significantly greater in non-treated rats with EIOP. Retinal TUNEL staining showed apoptosis in all ocular hypertensive rats. The presented data confirm the role of oxidative injury in EIOP and highlight the protective effect of MnTnHex-2-PyP(5+) treatment and NOS inhibition in ocular hypertension.

[Pathogenesis of hypertensive pain syndrome]

Comparative analysis of urea concentration in vitreous, vitreal fluid cavities and blood serum in patients with terminal painful glaucoma is performed based on laboratory data. Author proposes that pathogenesis of pain is related to "negative gradient of urea concentration", when urea concentration is higher in vitreous compared with blood serum. In the walls of ciliary processes where pain receptors are localized osmotic force causes tension provoking pain.

[Chemical composition features of vitreous in terminal glaucoma and hypertensive pain syndrome]

In patients with terminal glaucoma and hypertensive pain syndrome urea concentration in vitreous was 3,8-46,8 mmol/l and creatinine concentration was 0,036 - 0,126 mmol/l. Obtained values are comparable with those in blood serum and correlate with intensity of pain in damaged eye. Pain origin was found to be associated with elevation of urea concentration in vitreous compared with that in blood. It is proposed that urea accumulation in vitreous is one of significant factors of ocular pressure elevation in terminal glaucoma.

[Up to date methods of optic nerve evaluation in patients with optic neuropathy of various etiology]

132 patients (188 eyes) with proven optic neuropathy of non-glaucomatous origin were examined using static perimetry, visual evoked potential (flash and pattern types), optic coherent tomography of papilla and thickness of peripapillary nerve fiber layer. Sensitivity/ specificity of methods for identification of optic nerve diseases in acute stage were 92/75%, 92/84%, 90/92% respectively. Combination of these three methods let us identify optic neuropathy in 100% of cases, including latent forms.

Investigation into the vasospastic mechanisms in the pathogenesis of glaucomatous neuropathy

Spasm of blood vessels supplying the optic nerve head is considered one of possible ischaemic mechanisms of glaucomatous optic neuropathy.

PURPOSE

The aim of the study was to evaluate the role of two potent and long-acting vasoconstrictors: endothelin-1 (ET-1) and neuropetide Y (NPY) in the pathogenesis of glaucoma by: 1) measurement of plasma ET-1 and NPY concentrations in primary open-angle glaucoma (POAG) patients with high intraocular pressure (HTG patients) and with normal intraocular pressure (NTG patients) at baseline and following peripheral exposure to cold (cold-pressor test), 2) assessment whether changes, if any, in the plasma concentrations of both peptides following the cold-pressor test correlate with visual field defects.

MATERIAL AND METHODS

The study was conducted in three groups of subjects: 1) HTG patients, 2) NTG patients and 3) controls. All subjects were young and free from any cardiovascular disorders. ET-1 and NPY concentrations in the plasma were measured by radioimmunoassay (ET-1: Amersham International UK, NPY: Peninsula Laboratories INC). The cold-pressor test was performed by immersing the whole hand in ice-cold water (4 degrees C) for 2 minutes. Visual fields were examined using standard automated perimetry (Octopus 101, G-2 programme, normal strategy).

RESULTS

In the NTG patients the mean baseline plasma ET-1 concentration was significantly lower and the mean baseline plasma NPY concentration significantly higher compared to controls. On the other hand, there were no statistically significant differences in the mean baseline peptide levels between the HTG patients and the control subjects. After the cold-pressor test the mean ET-1 concentrations considerably increased in the three groups. The highest increase was seen in the NTG group and it was statistically significant compared to the HTG group and controls. Following the cold-pressor test the mean NPY concentration was significantly decreased in the NTG group, but remained virtually unchanged in the HTG group and controls. In the NTG patients, significant increase in the mean ET-1 concentration and decrease in the mean NPY concentration seen after the cold-pressor test were accompanied by a significant decrease in the mean MS (mean retinal sensitivity) value in the second eye examined after the cold-pressor test, but no correlation was found between changes in the MS values and changes in the ET-1 and NPY concentrations. There were no significant changes in the mean MS values after cold-pressor test in the HTG patients and controls.

CONCLUSIONS

Our findings suggest abnormal neuro-endothelial mechanisms of vascular tone control in NTG patients, related to the effects of ET-1 and NPY, secondary to endothelial dysfunction and to dysregulation of the autonomic nervous system. These abnormalities may involve potentiation of the vasoconstrictive effects of both ET-1 and NPY leading to the optic nerve head ischaemia and subsequent development of visual field defects in the course of normal-tension glaucoma.

Retinal vascular events after intravitreal bevacizumab

PURPOSE

To record retinal vascular events following intravitreal bevacizumab injection.

METHODS

Collaborative multi-centre retrospective case series.

RESULTS

Eight patients were documented to have central retinal artery occlusion (four patients), branch retinal artery occlusion, capillary occlusion, central retinal vein occlusion and branch retinal vein occlusion (one patient each) within 0-55 days (median 2 weeks) of intravitreal bevacizumab. All patients had several ocular and systemic risk factors for retinal vascular events: elevated intraocular pressure on discharge (four patients), pre-existent glaucoma (one patient), pre-existent ischaemic retinal vascular disorder (four patients), systemic hypertension (five patients), diabetes mellitus (three patients), coronary artery disease (four patients), carotid disease (three patients), smoking (two patients) and migraine (one patient).

CONCLUSION

The retinal vascular events may be associated with the underlying ocular disease under treatment or with the underlying systemic disease, may be related to an increased intraocular pressure post-injection constraining further an already poor retinal perfusion, the vasoconstrictor effect of bevacizumab, or a combination of all three.

Quantifying the effect of intraocular pressure reduction on the occurrence of glaucoma

PURPOSE

To estimate the effect of reducing intraocular pressure (IOP) on: (i) the incidence of primary open-angle glaucoma (POAG) in patients with ocular hypertension (OH), and (ii) the progression of glaucoma.

METHODS

A meta-analysis of relevant randomized controlled trials was conducted. A literature search was performed to identify trials with: a randomized comparison of IOP-lowering intervention versus placebo or no treatment; visual field loss or optic disc changes as outcome; and follow-up >6 months. A pooled relative risk (RR) was calculated by a random effects model. Risk reduction of glaucoma conversion per mmHg of IOP reduction was quantified in a meta-regression model.

RESULTS

We identified nine OH and one POAG trials. A meta-analysis of OH trials gives a pooled RR of 0.61 [95% confidence interval (CI) 0.45-0.83]. A meta-regression shows a decrease of the RR of glaucoma conversion by 14% with each mmHg extra IOP reduction (P = 0.045). No meta-analysis of POAG trials was performed because only one study has been identified.

CONCLUSION

There is sufficient evidence that OH therapy reduces the risk of conversion to glaucoma. This risk reduction increases with greater IOP reduction.