The Robust Lamina Cribrosa Vasculature: Perfusion and Oxygenation Under Elevated Intraocular Pressure

Purpose

Elevated intraocular pressure (IOP) is thought to cause lamina cribrosa (LC) blood vessel distortions and potentially collapse, adversely affecting LC hemodynamics, reducing oxygenation, and triggering, or contributing to, glaucomatous neuropathy. We assessed the robustness of LC perfusion and oxygenation to vessel collapses.

Methods

From histology, we reconstructed three-dimensional eye-specific LC vessel networks of two healthy monkey eyes. We used numerical simulations to estimate LC perfusion and from this the oxygenation. We then evaluated the effects of collapsing a fraction of LC vessels (0%-36%). The collapsed vessels were selected through three scenarios: stochastic (collapse randomly), systematic (collapse strictly by the magnitude of local experimentally determined IOP-induced compression), and mixed (a combination of stochastic and systematic).

Results

LC blood flow decreased linearly as vessels collapsed-faster for stochastic and mixed scenarios and slower for the systematic one. LC regions suffering severe hypoxia (oxygen <8 mm Hg) increased proportionally to the collapsed vessels in the systematic scenario. For the stochastic and mixed scenarios, severe hypoxia did not occur until 15% of vessels collapsed. Some LC regions had higher perfusion and oxygenation as vessels collapsed elsewhere. Some severely hypoxic regions maintained normal blood flow. Results were equivalent for both networks and patterns of experimental IOP-induced compression.

Conclusions

LC blood flow was sensitive to distributed vessel collapses (stochastic and mixed) and moderately vulnerable to clustered collapses (systematic). Conversely, LC oxygenation was robust to distributed vessel collapses and sensitive to clustered collapses. Locally normal flow does not imply adequate oxygenation. The actual nature of IOP-induced vessel collapse remains unknown.

A digoxin derivative that potently reduces intraocular pressure: efficacy and mechanism of action in different animal models

Glaucoma is a blinding disease. Reduction of intraocular pressure (IOP) is the mainstay of treatment, but current drugs show side effects or become progressively ineffective, highlighting the need for novel compounds. We have synthesized a family of perhydro-1,4-oxazepine derivatives of digoxin, the selective inhibitor of Na,K-ATPase. The cyclobutyl derivative (DcB) displays strong selectivity for the human α2 isoform and potently reduces IOP in rabbits. These observations appeared consistent with a hypothesis that in ciliary epithelium DcB inhibits the α2 isoform of Na,K-ATPase, which is expressed strongly in nonpigmented cells, reducing aqueous humor (AH) inflow. This paper extends assessment of efficacy and mechanism of action of DcB using an ocular hypertensive nonhuman primate model (OHT-NHP) (Macaca fascicularis). In OHT-NHP, DcB potently lowers IOP, in both acute (24 h) and extended (7-10 days) settings, accompanied by increased aqueous humor flow rate (AFR). By contrast, ocular normotensive animals (ONT-NHP) are poorly responsive to DcB, if at all. The mechanism of action of DcB has been analyzed using isolated porcine ciliary epithelium and perfused enucleated eyes to study AH inflow and AH outflow facility, respectively. 1) DcB significantly stimulates AH inflow although prior addition of 8-Br-cAMP, which raises AH inflow, precludes additional effects of DcB. 2) DcB significantly increases AH outflow facility via the trabecular meshwork (TM). Taken together, the data indicate that the original hypothesis on the mechanism of action must be revised. In the OHT-NHP, and presumably other species, DcB lowers IOP by increasing AH outflow facility rather than by decreasing AH inflow.NEW & NOTEWORTHY When applied topically, a cyclobutyl derivative of digoxin (DcB) potently reduces intraocular pressure in an ocular hypertensive nonhuman primate model (Macaca fascicularis), associated with increased aqueous humor (AH) flow rate (AFR). The mechanism of action of DcB involves increased AH outflow facility as detected in enucleated perfused porcine eyes and, in parallel, increased (AH) inflow as detected in isolated porcine ciliary epithelium. DcB might have potential as a drug for the treatment of open-angle human glaucoma.

Anterior Segment Optical Coherence Tomography for Cases of High Intraocular Pressure Following XEN Implant for Glaucoma

PRCIS

This study showed that the XEN patency should be verified by OCT imaging in cases of encapsulated blebs. Although fibrosis plays the principal role, humor aqueous flow reduction could affect the "spacer" effect that inhibits the fibroblast attachments.

PURPOSE

To evaluate the application of the anterior segment optical coherence tomography (AS-OCT) imaging in studying the relationship between a low flow rate through the XEN63 and the development of a cystic bleb.

METHODS

Retrospective case series of 3 eyes presenting a cystic bleb after an XEN63 implantation for uncontrolled intraocular pressure (IOP). Demographic and clinical data were obtained from medical records. The imaging findings, complications, and managements following the surgery were evaluated.

RESULTS

Three patients, with an average age of 67.3 years, initially showed a patent stent lumen and a functional bleb after surgery. The IOP of all eyes increased on average at 28.3 days from the surgery, with a mean value of 39.66 mm Hg. The slit lamp examination showed a cystic bleb. The AS-OCT imaging confirmed the previous finding and revealed either a partial or total occlusion of the stent internal ostium. A Nd:YAG laser, in proximity to the ostium, was performed to resolve the obstruction. Although the AS-OCT imaging showed the device patency and the IOP immediately decreased, the latter became elevated again. Consequently, in all the cases, a further needling procedure was needed to achieve an adequate IOP reduction. Six months after the two-step procedure, the IOP averaged 13.33 mm Hg, the XEN63 lumens appeared cleared, and the blebs showed a functional morphology. No adverse events were observed.

CONCLUSION

The development of a cystic bleb may result from an altered balance between the flow rate through the XEN63 and the fibrosis development in the postoperative healing process. A proper follow-up based on slit lamp biomicroscopy, IOP measurement, and AS-OCT imaging is advisable to estimate and manage a cystic bleb following XEN63 implantation.

Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms

Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings.

Blood Pressure and Glaucomatous Progression in a Large Clinical Population

PURPOSE

To investigate the effect of systemic arterial blood pressure (BP) on rates of progressive structural damage over time in glaucoma.

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 7501 eyes of 3976 subjects with glaucoma or suspected of glaucoma followed over time from the Duke Glaucoma Registry.

METHODS

Linear mixed models were used to investigate the effects of BP on the rates of retinal nerve fiber layer (RNFL) loss from spectral-domain OCT (SD-OCT) over time. Models were adjusted for intraocular pressure (IOP), gender, race, diagnosis, central corneal thickness (CCT), follow-up time, and baseline disease severity.

MAIN OUTCOME MEASURE

Effect of mean arterial pressure (MAP), systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) on rates of RNFL loss over time.

RESULTS

A total of 157 291 BP visits, 45 408 IOP visits, and 30 238 SD-OCT visits were included. Mean rate of RNFL change was -0.70 μm/year (95% confidence interval, -0.72 to -0.67 μm/year). In univariable models, MAP, SAP, and DAP during follow-up were not significantly associated with rates of RNFL loss. However, when adjusted for mean IOP during follow-up, each 10 mmHg reduction in mean MAP (-0.06 μm/year; P = 0.007) and mean DAP (-0.08 μm/year; P < 0.001) but not SAP (-0.01 μm/year; P = 0.355) was associated with significantly faster rates of RNFL thickness change over time. The effect of the arterial pressure metrics remained significant after additional adjustment for baseline age, diagnosis, sex, race, follow-up time, disease severity, and corneal thickness.

CONCLUSIONS

When adjusted for IOP, lower MAP and DAP during follow-up were significantly associated with faster rates of RNFL loss, suggesting that levels of systemic BP may be a significant factor in glaucoma progression.

Interplay between intraocular and intracranial pressure effects on the optic nerve head in vivo

Intracranial pressure (ICP) has been proposed to play an important role in the sensitivity to intraocular pressure (IOP) and susceptibility to glaucoma. However, the in vivo effects of simultaneous, controlled, acute variations in ICP and IOP have not been directly measured. We quantified the deformations of the anterior lamina cribrosa (ALC) and scleral canal at Bruch's membrane opening (BMO) under acute elevation of IOP and/or ICP. Four eyes of three adult monkeys were imaged in vivo with OCT under four pressure conditions: IOP and ICP either at baseline or elevated. The BMO and ALC were reconstructed from manual delineations. From these, we determined canal area at the BMO (BMO area), BMO aspect ratio and planarity, and ALC median depth relative to the BMO plane. To better account for the pressure effects on the imaging, we also measured ALC visibility as a percent of the BMO area. Further, ALC depths were analyzed only in regions where the ALC was visible in all pressure conditions. Bootstrap sampling was used to obtain mean estimates and confidence intervals, which were then used to test for significant effects of IOP and ICP, independently and in interaction. Response to pressure manipulation was highly individualized between eyes, with significant changes detected in a majority of the parameters. Significant interactions between ICP and IOP occurred in all measures, except ALC visibility. On average, ICP elevation expanded BMO area by 0.17 mm² at baseline IOP, and contracted BMO area by 0.02 mm² at high IOP. ICP elevation decreased ALC depth by 10 μm at baseline IOP, but increased depth by 7 μm at high IOP. ALC visibility decreased as ICP increased, both at baseline (-10%) and high IOP (-17%). IOP elevation expanded BMO area by 0.04 mm² at baseline ICP, and contracted BMO area by 0.09 mm² at high ICP. On average, IOP elevation caused the ALC to displace 3.3 μm anteriorly at baseline ICP, and 22 μm posteriorly at high ICP. ALC visibility improved as IOP increased, both at baseline (5%) and high ICP (8%). In summary, changing IOP or ICP significantly deformed both the scleral canal and the lamina of the monkey ONH, regardless of the other pressure level. There were significant interactions between the effects of IOP and those of ICP on LC depth, BMO area, aspect ratio and planarity. On most eyes, elevating both pressures by the same amount did not cancel out the effects. Altogether our results show that ICP affects sensitivity to IOP, and thus that it can potentially also affect susceptibility to glaucoma.

Strain by virtual extensometers and video-imaging optical coherence tomography as a repeatable metric for IOP-Induced optic nerve head deformations

PURPOSE

To determine if in vivo strain response of the Optic Nerve Head (ONH) to IOP elevation visualized using Optical Coherence Tomography (OCT) video imaging and quantified using novel virtual extensometers was able to be provided repeatable measurements of tissue specific deformations.

METHODS

The ONHs of 5 eyes from 5 non-human primates (NHPs) were imaged by Spectralis OCT. A vertical and a horizontal B-scan of the ONH were continuously recorded for 60 s at 6 Hz (video imaging mode) during IOP elevation from 10 to 30 mmHg. Imaging was repeated over three imaging sessions. The 2D normal strain was computed by template-matching digital image correlation using virtual extensometers. ANOVA F-test (F) was used to compare inter-eye, inter-session, and inter-tissue variability for the prelaminar, Bruch's membrane opening (BMO), lamina cribrosa (LC) and choroidal regions (against variance the error term). F-test of the ratio between inter-eye to inter-session variability was used to test for strain repeatability across imaging sessions (FIS).

RESULTS

Variability of strain across imaging session (F = 0.7263, p = 0.4855) and scan orientation was not significant (F = 1.053, p = 0.3066). Inter session variability of strain was significantly lower than inter-eye variability (FIS = 22.63, p = 0.0428) and inter-tissue variability (FIS = 99.33 p = 0.00998). After IOP elevation, strain was highest in the choroid (-18.11%, p < 0.001), followed by prelaminar tissue (-11.0%, p < 0.001), LC (-3.79%, p < 0.001), and relative change in BMO diameter (-0.57%, p = 0.704).

CONCLUSIONS

Virtual extensometers applied to video-OCT were sensitive to the eye-specific and tissue-specific mechanical response of the ONH to IOP and were repeatable across imaging sessions.

Stanniocalcin-1 Reduced Intraocular Pressure in Two Models of Ocular Hypertension

Purpose/Aim: Glaucomatous optic neuropathy (GON) remains the world's leading cause of irreversible blindness. Treatments including topical medications are directed at reducing intraocular pressure (IOP), the most significant risk factor for GON. Current medications, while generally effective, are limited by insufficient response and side-effects in some patients. In search of a more targeted therapy that acts downstream of existing medications that has a potential for a lower side effect profile, our laboratory has identified Stanniocalcin-1 (STC-1), a multifunctional hormone, as an effector molecule in latanoprost-mediated IOP reduction with similar IOP-lowering efficacy as latanoprost in normotensive mice.Materials and methods: To investigate whether STC-1 can also reduce IOP in ocular hypertensive mice, we used a steroid-induced ocular hypertensive mouse model characterized by trabecular meshwork dysfunction as well as the DBA/2J mouse as an inherited model of pigment dispersion and secondary angle closure. Steroid-induced ocular hypertension was induced by weekly injections of dexamethasone into the conjunctival fornix of wild-type C57BL/6J mice (6-8 months old). After confirmation of the steroid response, mice were administered STC-1 or phosphate buffered saline (PBS) topically once daily for six weeks. For DBA/2J mice (14 months old), after baseline IOP measurements, mice were treated topically once daily with STC-1 or PBS for 5 days and IOP was assessed twice daily.Results: In steroid-induced ocular hypertensive mice, STC-1 lowered IOP by 26% (P < .001, week three) and maintained this level of IOP reduction throughout the remainder of the treatment period (P < .001, week six). In DBA/2J mice, STC-1 lowered IOP by 37% (P < .001).Conclusions: Together, these data show that STC-1 reduced IOP in two models of ocular hypertension with different mechanisms of outflow obstruction.

LONG-TERM INCIDENCE AND RISK FACTORS OF OCULAR HYPERTENSION FOLLOWING DEXAMETHASONE-IMPLANT INJECTIONS: THE SAFODEX-2 STUDY

PURPOSE

To analyze the incidence, risk factors, and time to onset of ocular hypertension (OHT) after intravitreal injections (IVI) of dexamethasone implant and to evaluate the long-term cumulative probability of intraocular pressure elevation.

METHODS

Eyes of patients having received at least one dexamethasone implant IVI between October 2010 and February 2015 were included in the present study. Ocular hypertension was defined as intraocular pressure > 25 mmHg and/or an increase of 10 mmHg over the follow-up period compared with baseline intraocular pressure.

RESULTS

Four hundred ninety-four eyes were studied in 410 patients. For a total of 1,371 IVI, the incidence of OHT was 32.6% in the study eyes with a mean follow-up period of 30 months (3-62.5) and a median follow-up of 29 months. Pressure-lowering treatment was introduced for 36.9% of eyes. Topical treatment alone was sufficient to manage OHT in 97%. Young age, male sex, uveitis and retinal vein occlusion, and glaucoma treated with a double- or triple-combination topical pressure-lowering medication were found to be risk factors for OHT. The incidence of OHT did not change with an increase in the number of IVI, and there was no cumulative effect, defining by an increase of the incidence of OHT in patients after repeated IVI (P = 0.248).

CONCLUSION

This study confirmed that OHT is of moderate incidence, transient, controlled by topical treatment and provides data on the long-term cumulative probability of intraocular pressure elevation in a large cohort of eyes treated with dexamethasone implant IVI. Repeat injections of dexamethasone implant neither increase nor decrease the risk of OHT.

miRNA Changes in Retinal Ganglion Cells after Optic Nerve Crush and Glaucomatous Damage

The purpose of this study was to characterize the miRNA profile of purified retinal ganglion cells (RGC) from healthy and diseased rat retina. Diseased retina includes those after a traumatic optic nerve crush (ONC), and after ocular hypertension/glaucoma. Rats were separated into four groups: healthy/intact, 7 days after laser-induced ocular hypertension, 2 days after traumatic ONC, and 7 days after ONC. RGC were purified from rat retina using microbeads conjugated to CD90.1/Thy1. RNA were sequenced using Next Generation Sequencing. Over 100 miRNA were identified that were significantly different in diseased retina compared to healthy retina. Considerable differences were seen in the miRNA expression of RGC 7 days after ONC, whereas after 2 days, few changes were seen. The miRNA profiles of RGC 7 days after ONC and 7 days after ocular hypertension were similar, but discrete miRNA differences were still seen. Candidate mRNA showing different levels of expression after retinal injury were manipulated in RGC cultures using mimics/AntagomiRs. Of the five candidate miRNA identified and subsequently tested for therapeutic efficacy, miR-194 inhibitor and miR-664-2 inhibitor elicited significant RGC neuroprotection, whereas miR-181a mimic and miR-181d-5p mimic elicited significant RGC neuritogenesis.

Chronic mild and acute severe glaucomatous neurodegeneration derived from silicone oil-induced ocular hypertension

Recently, we established silicone oil-induced ocular hypertension (SOHU) mouse model with significant glaucomatous neurodegeneration. Here we characterize two additional variations of this model that simulate two distinct glaucoma types. The first is a chronic model produced by high frequency (HF) pupillary dilation after SO-induced pupillary block, which shows sustained moderate IOP elevation and corresponding slow, mild glaucomatous neurodegeneration. We also demonstrate that although SO removal quickly returns IOP to normal, the glaucomatous neurodegeneration continues to advance to a similar degree as in the HF group without SO removal. The second, an acute model created by no pupillary dilation (ND), shows a greatly elevated IOP and severe inner retina degeneration at an early time point. Therefore, by a straightforward dilation scheme, we extend our original SOHU model to recapitulate phenotypes of two major glaucoma forms, which will be invaluable for selecting neuroprotectants and elucidating their molecular mechanisms.

Characterizing and quantifying the temporal relationship between structural and functional change in glaucoma

PURPOSE

To characterize and quantify the temporal relationship between structural and functional change in glaucoma.

METHODS

120 eyes of 120 patients with ocular hypertension or primary open-angle glaucoma were selected from the Diagnostic Innovations in Glaucoma Study or the African Descent and Glaucoma Evaluation Study. Patients had 11 visits, separated by at least 3 months over 5 to 10 years. Each visit had rim area (RA) and mean sensitivity (MS) measurements taken within a 30-day period. The structure-function (SF) relationship was summarized using conventional and modified cross-correlation functions (CCFs), which identified the strongest absolute and positive correlation, respectively. Patients were categorized in one of the following three groups: RA and MS evolved simultaneously (lag = 0), RA preceded MS (lag<0), and MS preceded RA (lag>0). Lagging regression analysis was used to examine the variations of the SF relationship within groups.

RESULTS

The number of participants, mean visit lag, and mean correlation (standard deviation) were, for the conventional and modified CCFs, respectively: lag = 0 [16, 0, 0.53 (0.10) and 16, 0, 0.46 (0.11)]; lag<0 [50, -2.94, 0.51 (0.11) and 55, -3.45, 0.44 (0.12)], and lag>0 [54, 3.35, 0.53 (0.13) and 49, 3.78, 0.45 (0.12)]. A significant difference of the visit lag relation within groups was identified using lagging regression analysis (p<0.0001).

CONCLUSIONS

The strongest relationship between structure and function was obtained at different visit lags in different patients. This finding also suggests that the SF relationship should be addressed at the subject level when using both measurements jointly to model glaucoma progression.

Citicoline Modulates Glaucomatous Neurodegeneration Through Intraocular Pressure-Independent Control

Glaucoma is a neurodegenerative disease that causes progressive, irreversible vision loss. Currently, intraocular pressure (IOP) is the only modifiable risk factor for glaucoma. However, glaucomatous degeneration may continue despite adequate IOP control. Therefore, there exists a need for treatment that protects the visual system, independent of IOP. This study sought, first, to longitudinally examine the neurobehavioral effects of different magnitudes and durations of IOP elevation using multi-parametric magnetic resonance imaging (MRI), optokinetics and histology; and, second, to evaluate the effects of oral citicoline treatment as a neurotherapeutic in experimental glaucoma. Eighty-two adult Long Evans rats were divided into six groups: acute (mild or severe) IOP elevation, chronic (citicoline-treated or untreated) IOP elevation, and sham (acute or chronic) controls. We found that increasing magnitudes and durations of IOP elevation differentially altered structural and functional brain connectivity and visuomotor behavior, as indicated by decreases in fractional anisotropy in diffusion tensor MRI, magnetization transfer ratios in magnetization transfer MRI, T1-weighted MRI enhancement of anterograde manganese transport, resting-state functional connectivity, visual acuity, and neurofilament and myelin staining along the visual pathway. Furthermore, 3 weeks of oral citicoline treatment in the setting of chronic IOP elevation significantly reduced visual brain integrity loss and visual acuity decline without altering IOP. Such effects sustained after treatment was discontinued for another 3 weeks. These results not only illuminate the close interplay between eye, brain, and behavior in glaucomatous neurodegeneration, but also support a role for citicoline in protecting neural tissues and visual function in glaucoma beyond IOP control.

Associating the biomarkers of ocular blood flow with lamina cribrosa parameters in normotensive glaucoma suspects. Comparison to glaucoma patients and healthy controls

Purpose

To evaluate association between ocular blood flow biomarkers and lamina cribrosa parameters in normotensive glaucoma suspects compared to glaucoma patients and healthy controls.

Methods

A total of 211 subjects (72 normotensive glaucoma suspects, 70 with primary open-angle glaucoma and 69 controls) were included. Ocular blood flow biomarkers in ophthalmic artery, central retinal artery, as well as in nasal and temporal short posterior ciliary arteries were measured using colour Doppler imaging. Lamina cribrosa position was assessed by measuring its depth, deflection depth, lamina cribrosa shape index and its horizontal equivalent (LCSI_H) on B-scan images obtained using optical coherence tomography.

Results

Ocular blood flow biomarkers in glaucoma patients were statistically significantly reduced when compared to healthy controls in peak systolic velocity (PSV) (P = 0.001 in ophthalmic artery and P<0.001 in central retinal artery) and mean flow velocity (V_m) (P = 0.008 in ophthalmic artery and P = 0.008 in central retinal artery), but not statistically significantly different to that of glaucoma suspects except for PSV in central retinal artery (P = 0.011). Statistically significant correlations corrected for age, central corneal thickness and intraocular pressure were found in glaucoma patients between LCSI_H and end diastolic velocity of central retinal artery (P = 0.011), and of nasal short posterior ciliary artery (P = 0.028), and between LCSI_H and V_m of central retinal artery (P = 0.011) and of nasal short posterior ciliary artery (P = 0.007). No significant correlations were observed between these parameters in glaucoma suspects and healthy controls.

Conclusions

Impaired ocular blood flow associated with the deformation of lamina cribrosa was found in glaucoma patients, whereas glaucoma suspects had similar lamina cribrosa shape to glaucoma patients but that deformation was not associated with ocular blood flow biomarkers.

Risk of Airborne COVID-19 Transmission While Performing Humphrey Visual Field Testing

PRECIS

Designing and demonstrating an experiment that shows the risk of airborne transmission of COVID-19 between patients having visual fields analyzed is low.

PURPOSE

The aim was to investigate the possibility of airborne transmission of COVID-19 during Humphrey visual field testing in a real-world scenario.

METHODS

A particle counter was placed within the bowl of Humphrey visual field analyzer (HFA) before and after turning on the machine to ascertain the effect of the air current produced by the ventilation system on aerosols. A second experiment was run where the particle counter was placed in the bowl and recorded particulates, in the air, as a 24-2 SITA standard was performed by a mock patient and then again immediately after the patient had moved away. We measured aerosol particle counts sized ≤0.3 μm, >0.3≤0.5 μm, >0.5≤1 μm, >1≤2.5 μm, >2.5≤5 μm, and >5≤10 μm.

RESULTS

Particulates of all sizes were shown to be significantly reduced within the bowl after turning the machine on, demonstrating that the air current produced by the HFA pushes air out of the bowl and it cannot stagnate. There was no significant difference in measurement of aerosol while there was a patient performing the test and immediately after they had moved away, suggesting that aerosols breathed out by the patient are not able to remain in suspension in the bowl because of the ventilation current.

CONCLUSION

There is no significant difference between aerosol count in the bowl of a HFA before, during and after testing. This suggests the risk of airborne transmission of COVID-19 is low between subsequent patients. This is in keeping with manufacturer's guidance on Humphrey visual field testing.

Factors Associated With Favorable Laser Trabeculoplasty Response: IRIS Registry Analysis

PURPOSE

We examined patients in a large clinical registry to assess factors associated with laser trabeculoplasty (LTP) responses.

DESIGN

Retrospective cohort study.

METHODS

StudyPopulation: LTP patients in the Intelligent Research in Sight (IRIS) Registry, 2013-2018.

OBSERVATION

IRIS Registry data were extracted if the eye had a procedural code for LTP and a glaucoma diagnosis. Eyes were excluded if LTP laterality or baseline intraocular pressure (IOP) could not be determined. Following LTP, "nonresponders" were those with <20% IOP reduction after 8 weeks, while "responders" were those with ≥20% IOP reduction. MainOutcomeMeasures: Proportion of responders, odds ratios (OR) of pre-LTP factors associated with being a nonresponder.

RESULTS

A total of 263,480 eyes were included, with mean age 71.4 ± 11.7 years. Mean baseline IOP was 19.1 ± 5.0 mm Hg, mean number of pre-LTP medications was 2.1 ± 1.5. Response rate was 36.9% overall and 68.8% for those with baseline IOP >24 mm Hg. Higher baseline IOP was associated with reduced odds of nonresponse (OR = 0.60, P < .0001 for a 3 mm Hg increase). Angle recession, uveitis, and aphakia increased the odds of a nonresponse (ORs 2.46, 1.50 (both P < .0001), and 1.55 (P = .0259), respectively). In nonresponders with at least 1 medication at baseline, 76.3% of eyes had fewer medications postoperatively.

CONCLUSIONS

Lower baseline IOP, angle recession, uveitis, and aphakia were associated with increased odds of nonresponse. Future studies that analyze LTP responder survival and implementation lag would facilitate resource optimization in glaucoma therapy.

Isolation and characterization of novel primary cells from the human distal outflow pathway

Ocular hypertension occurs due to increased resistance to aqueous humor removal through the conventional outflow pathway. Unlike the proximal region of the conventional outflow pathway, the distal region has not been well studied, mostly due to lack of model systems. Here we describe isolation and characterization of human primary vascular distal outflow pathway (VDOP) cells from the distal region of the conventional outflow pathway. Tissue from the distal region was isolated from human corneo-scleral rims, digested with collagenase type I (100 U/ml) and placed on gelatin coated plates to allow cellular growth in Dulbecco's Modified Eagle's Medium (low glucose) containing fetal bovine serum and antibiotic/antimycotic. VDOP cells showed consistent proliferation for up to 7 passages, retained endothelial-like nature of the parent tissues and showed a unique marker phenotype of Lectin+VEGFR2-CD34-NG2- that was distinct from neighboring trabecular meshwork (Lectin+VEGFR2-CD34-NG2+) and Schlemm's canal (Lectin+VEGFR2+CD34+NG2+) cells. Dexamethasone treated VDOP cells did not express myocilin and did not form cross-linked actin networks, in contrast to trabecular meshwork cells. These data show that VDOP cells are unique to the distal outflow region and can be used as a viable in vitro model system to understand the biology of the distal outflow pathway and intraocular pressure regulation.

Randomized, Double-Masked Trial of Netarsudil 0.02% Ophthalmic Solution for Prevention of Corticosteroid-Induced Ocular Hypertension

PURPOSE

To assess whether prophylactic use of netarsudil 0.02% ophthalmic solution reduces the risk of intraocular pressure (IOP) elevation associated with prolonged use of topical corticosteroids to prevent cornea transplantation rejection.

DESIGN

Prospective, randomized clinical trial.

METHODS

In this study, 120 subjects were randomized to use netarsudil (off-label) or placebo once daily for 9 months after Descemet membrane endothelial keratoplasty, and 71 fellow eyes were enrolled and assigned to the opposite treatment arm. Participants concurrently used topical prednisolone acetate 1% 4× daily for 3 months, 3× daily for a month, twice daily for a month, and once daily for 4 months. The main outcome was IOP elevation (defined as IOP ≥24 mm Hg or an increase of ≥10 mm Hg over baseline) assessed by Kaplan-Meier and proportional hazards analyses, taking loss to follow-up into consideration.

RESULTS

Overall, 95 eyes were assigned to netarsudil and 96 to placebo; 15 eyes (16%) were withdrawn early from the netarsudil arm because of ocular irritation. The rate of IOP elevation was 14% with netarsudil and 21% with placebo (relative risk: 0.6; 95% confidence interval: 0.3-1.3; P = .23). IOP was >30 mm Hg in 7.8% assigned to netarsudil versus 7.4% assigned to placebo (P = .84). Median 6-month central endothelial cell loss was 31% versus 29% with netarsudil versus placebo, respectively (P = .49).

CONCLUSIONS

Netarsudil did not produce a statistically significant reduction in the risk of steroid-induced IOP elevation after corneal transplantation relative to placebo.

Brinzolamide/brimonidine fixed-dose combination bid as an adjunct to a prostaglandin analog for open-angle glaucoma/ocular hypertension

PURPOSE

To evaluate the additive intraocular pressure-lowering effect of twice-daily brinzolamide 1%/brimonidine 0.2% fixed-dose combination (BBFC) as an adjunct to a prostaglandin analog (PGA) in patients with open-angle glaucoma or ocular hypertension insufficiently controlled with PGA monotherapy.

METHODS

In this Phase 4, double-masked trial, patients aged ⩾18 years, with a mean intraocular pressure of ⩾19 and <32 mm Hg in at least one eye were randomized (1:1) to receive BBFC + PGA (n = 96) or vehicle + PGA (n = 92) for 6 weeks. The primary endpoint was the mean change in diurnal intraocular pressure from baseline (averaged over 09:00 and 11:00 h) at Week 6.

RESULTS

The mean diurnal intraocular pressure at baseline was similar in the BBFC + PGA (22.8 mm Hg) and vehicle + PGA (22.9 mm Hg) groups. The least squares mean change in diurnal intraocular pressure from baseline at Week 6 was greater with BBFC + PGA (-5.59 mm Hg (95% confidence interval: -6.2 to -5.0)) than with vehicle + PGA (-2.15 mm Hg (95% confidence interval: -2.7 to -1.6)); the treatment difference was statistically significant in favor of BBFC + PGA (-3.44 mm Hg, (95% confidence interval: -4.2 to -2.7); p < 0.001). Ocular adverse events were reported in 21.1% and 8.7% of patients in the BBFC + PGA and vehicle + PGA groups, respectively. The most frequent ocular adverse event was ocular hyperemia (5.3%) in the BBFC + PGA group and blurred vision (2.2%) in the vehicle + PGA group.

CONCLUSION

BBFC + PGA significantly reduced mean diurnal intraocular pressure than PGA alone in patients with open-angle glaucoma or ocular hypertension. The safety findings with BBFC + PGA were consistent with the known safety profile of the individual medications.

A Strategy for Seeding Point Error Assessment for Retesting (SPEAR) in Perimetry Applied to Normal Subjects, Glaucoma Suspects, and Patients With Glaucoma

PURPOSE

We sought to determine the impact of seeding point errors (SPEs) as a source of low test reliability in perimetry and to develop a strategy to mitigate this error early in the test.

DESIGN

Cross-sectional study.

METHODS

Visual field test results from 1 eye of 364 patients (77 normal eyes, 178 glaucoma suspect eyes, and 109 glaucoma eyes) were used to develop models for identifying SPE. Two test cohorts (326 undertaking Swedish interactive thresholding algorithm [SITA]-Faster and 327 glaucoma eyes undertaking SITA-Standard) were used to prospectively evaluate the models for identifying SPEs. Global visual field metrics were compared among reliable and unreliable results. Regression models were used to identify factors distinguishing SPEs from non-SPEs. Models were evaluated using receiver operating characteristic (ROC) curves.

RESULTS

In the test cohorts, SITA-Faster produced a higher rate of unreliable visual field results (30%-49.7%) compared with SITA-Standard (10.8%-16.6%). SPEs contributed to most of the unreliable results in SITA-Faster (57.5%-64.9%) compared with gaze tracker deviations accounting for most of the unreliable results in SITA-Standard (40%-77.8%). In SITA-Faster, results with SPEs had worse global indices and more clusters of sensitivity reduction than reliable results. Our best model (using 9 test locations) can identify SPEs with an area under the ROC curve of 0.89.

CONCLUSION

SPEs contribute to a large proportion of unreliable visual field test results, particularly when using SITA-Faster. We propose a useful model for identifying SPEs early in the test that can then guide retesting using both SITA algorithms. We provide a simplified framework for the perimetrist to improve the overall fidelity of the test result.

Ocular hypertension in Axenfeld-Rieger Syndrome

Purpose: to describe a clinical case of ocular hypertension (OHT) in Axenfeld-Rieger Syndrome (ARS).

Method: Observational case report of a 43-year-old woman with background of OHT. The data was collected originally with a standardized electronic medical record. A complete ophthalmologic examination was performed.

Results: In the biomicroscopy, a posterior embryotoxon, iris atrophy with absence of crypts and irregularity of pigmentation, and discoria in OU were observed. Gonioscopy revealed an open angle with a prominent and anterior displaced Schwalbe line. Ocular fundus (OF) demonstrated small and oblique papillae, with normal neurorretinal ring. Functional tests were normal. The patient did not present systemic pathologies, so the diagnosis of Rieger anomaly was made. The IOP control was achieved with aqueous humor suppressants.

Conclusions: Glaucoma is the main cause of visual morbidity in patients with ARS, therefore a complete periodic ophthalmological exam is a priority.

Abbreviations :ARS = Axenfeld-Rieger Syndrome, RP = retinitis pigmentosa, IOP = Intraocular Pressure, BCVA = Best Corrected Visual Acuity, OR = right eye, OS = left eye, OU = both eyes, OF = ocular fundus, OCT = optical coherence tomography, VF = visual field, TBC = trabeculectomy

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.

Ability of 24-2C and 24-2 Grids to Identify Central Visual Field Defects and Structure-Function Concordance in Glaucoma and Suspects

PURPOSE

The purpose of this study was to compare the ability of the 24-2 test grid with that of the 24-2C test grid to measure visual field global indices, identify central visual field defects, and facilitate macular structure-function analysis with optical coherence tomography (OCT) scans in glaucoma suspects and glaucoma patients.

DESIGN

Prospective, cross-sectional study.

METHODS

One eye from each of 100 glaucoma suspects and glaucoma patients (60 undergoing SITA-Faster [Zeiss Meditec] testing on 24-2 and 24-2C; 40 undergoing SITA-Standard [Zeiss Meditec] testing on 24-2 and SITA-Faster on 24-2C) were included in the study. Global visual field indices, test duration, and pattern deviation results were extracted. The deviation map from the Cirrus OCT (Carl Zeiss Meditec) Ganglion Cell Analysis (GCA) was extracted, and structure-function relationships were compared after correction of the visual field test stimulus location that stimulated the corresponding retinal ganglion cell.

RESULTS

Global index results of the 24-2 grid were similar to those of the 24-2C grid, and both identified a comparable number of clusters of visual field defects. Centrally, the 24-2C grid identified more clusters of defects than the 24-2 grid, but this was not statistically significant. Although the 24-2C test locations resulted in more instances of structure-function concordance than the 24-2 locations, half the locations in the 24-2C grid fell close to or outside the GCA grid when corrected for ganglion cell displacement.

CONCLUSIONS

The 24-2C returned global visual field indices similar to the 24-2 grid but tended to identify more clusters of central functional defects. Central structure-function concordance was better achieved using the 24-2C grid, but half of the visual field test locations did not coincide with the commonly used macular thickness scan.

Visual Field Outcomes from the Multicenter, Randomized Controlled Laser in Glaucoma and Ocular Hypertension Trial (LiGHT)

PURPOSE

To compare visual field outcomes of ocular hypertensive and glaucoma patients treated first with medical therapy with those treated first with selective laser trabeculoplasty (SLT).

DESIGN

Secondary analysis of patients from the Laser in Glaucoma and Ocular Hypertension study, a multicenter randomized controlled trial.

PARTICIPANTS

Three hundred forty-four patients (588 eyes) treated first with medical therapy and 344 patients (590 eyes) treated first with SLT.

METHODS

Visual fields (VFs) were measured using standard automated perimetry and arranged in series (median length and duration, 9 VFs over 48 months). Hierarchical linear models were used to estimate pointwise VF progression rates, which were then averaged to produce a global progression estimate for each eye. Proportions of points and patients in each treatment group with fast (<-1 dB/year) or moderate (<-0.5 dB/year) progression were compared using log-binomial regression.

MAIN OUTCOME MEASURES

Pointwise and global progression rates of total deviation (TD) and pattern deviation (PD).

RESULTS

A greater proportion of eyes underwent moderate or fast TD progression in the medical therapy group compared with the SLT group (26.2% vs. 16.9%; risk ratio [RR], 1.55; 95% confidence interval [CI], 1.23-1.93; P < 0.001). A similar pattern was observed for pointwise rates (medical therapy, 26.1% vs. SLT, 19.0%; RR, 1.37; 95% CI, 1.33-1.42; P < 0.001). A greater proportion of pointwise PD rates were categorized as moderate or fast in the medical therapy group (medical therapy, 11.5% vs. SLT, 8.3%; RR, 1.39; 95% CI, 1.32-1.46; P < 0.001). No statistical difference was found in the proportion of eyes that underwent moderate or fast PD progression (medical therapy, 9.9% vs. SLT, 7.1%; RR, 1.39; 95% CI, 0.95, 2.03; P = 0.0928).

CONCLUSIONS

A slightly larger proportion of ocular hypertensive and glaucoma patients treated first with medical therapy underwent rapid VF progression compared with those treated first with SLT.

Endocannabinoid metabolism and transport as targets to regulate intraocular pressure

Cannabinoids are part of an endogenous signaling system found throughout the body, including the eye. Hepler and Frank showed in the early 1970s that plant cannabinoids can lower intraocular pressure (IOP), an effect since shown to occur via cannabinoid CB1 and GPR18 receptors. Endocannabinoids are synthesized and metabolized enzymatically. Enzymes implicated in endocannabinoids breakdown include monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH), but also ABHD12, NAAA, and COX-2. Inhibition of MAGL activity raises levels of the endocannabinoid 2-arachidonoyl glycerol and substantially lowers IOP. Blocking other cannabinoid metabolizing enzymes or cannabinoid transporters may similarly contribute to lowering IOP and so serve as therapeutic targets for treating glaucoma. We have tested blockers for several cannabinoid-metabolizing enzymes and transporters (FABP5 and membrane reuptake) for their ability to alter ocular pressure in a murine model of IOP. Of FAAH, ABHD12, NAAA, and COX2, only FAAH was seen to play a role in regulation of IOP. Only the FAAH blocker URB597 lowered IOP, but in a temporally, diurnally, and sex-specific manner. We also tested two blockers of cannabinoid transport (SBFI-26 and WOBE437), finding that each lowered IOP in a CB1-dependent manner. Though we see a modest, limited role for FAAH, our results suggest that MAGL is the primary cannabinoid-metabolizing enzyme in regulating ocular pressure, thus pointing towards a role of 2-arachidonoyl glycerol. Interestingly, inhibition of cannabinoid transport mechanisms independent of hydrolysis may prove to be an alternative strategy to lower ocular pressure.

The Relationship Between Corneal Hysteresis and Retinal Ganglion Cells - A Step Forward in Early Glaucoma Diagnosis

BACKGROUND Glaucoma is a major cause of irreversible visual field (VF) loss across the world. Many studies have assessed the accuracy of glaucoma diagnostic tests for a more precise diagnosis to quickly identify patients with higher risk of progression. MATERIAL AND METHODS We conducted a study that included 214 eyes divided into 3 groups: 79 eyes from patients diagnosed with primary open-angle glaucoma (POAG), 68 eyes from patients diagnosed with ocular hypertension (OH), and 67 eyes from normal individuals (normal eyes, NE). All patients included in the study received a complete checkup. RESULTS In POAG patients, means of central corneal thickness (CCT), corneal hysteresis (CH), corneal resistance factor (CRF), mean defect (MD), visual field index (VFI), peripapillary retinal nerve fiber layer (pRNFL), and ganglion cell complex (GCC) are lower than in OH patients, and in NE are higher than in both groups. Also, we found a statistically significant direct correlation between CH and GCC thickness. Further statistical analysis revealed that both pRNFL thickness and GCC thickness are significantly influenced by CH value in a precise manner. CONCLUSIONS The first cell type affected in glaucoma is the retinal ganglion cell. We found a positive correlation between GCC thickness and CH, suggesting that CH might be a parameter to consider in the evaluation of all glaucoma patients from their first examination. Moreover, both pRNFL thickness and GCC thickness are influenced by CH, suggesting the utility of monitoring the value of CH at every checkup to detect its decrease in glaucoma patients.

Visual Field Estimation by Probabilistic Classification

The gold standard clinical tool for evaluating visual dysfunction in cases of glaucoma and other disorders of vision remains the visual field or threshold perimetry exam. Administration of this exam has evolved over the years into a sophisticated, standardized, automated algorithm that relies heavily on specifics of disease processes particular to common retinal disorders. The purpose of this study is to evaluate the utility of a novel general estimator applied to visual field testing. A multidimensional psychometric function estimation tool was applied to visual field estimation. This tool is built on semiparametric probabilistic classification rather than multiple logistic regression. It combines the flexibility of nonparametric estimators and the efficiency of parametric estimators. Simulated visual fields were generated from human patients with a variety of diagnoses, and the errors between simulated ground truth and estimated visual fields were quantified. Error rates of the estimates were low, typically within 2 dB units of ground truth on average. The greatest threshold errors appeared to be confined to the portions of the threshold function with the highest spatial frequencies. This method can accurately estimate a variety of visual field profiles with continuous threshold estimates, potentially using a relatively small number of stimuli.

Schlemm Canal and Trabecular Meshwork Features in Highly Myopic Eyes With Early Intraocular Pressure Elevation After Cataract Surgery

PURPOSE

To investigate the morphologic features of the Schlemm canal and trabecular meshwork in highly myopic eyes with early intraocular pressure (IOP) elevation after cataract surgery.

DESIGN

Retrospective case-control study.

METHODS

Eighty-eight highly myopic eyes of 88 patients after uneventful cataract surgery were included, 31 of which had early postoperative IOP elevation and 57 of which did not. The morphologic features of the Schlemm canal and trabecular meshwork, collected with swept-source optical coherence tomography before surgery, were reviewed. Backwards stepwise multiple linear regression was used to investigate the anatomic risk factors for early IOP elevation in highly myopic eyes.

RESULTS

Highly myopic eyes with early postoperative IOP elevation had smaller Schlemm canal vertical diameter and area, as well as smaller trabecular meshwork thickness and width, in each quadrant than the non-elevation group. There was no significant difference in Schlemm canal horizontal diameter between the IOP elevation and non-elevation groups. In the highly myopic eyes, average Schlemm canal vertical diameter, Schlemm canal area, trabecular meshwork thickness, and width were all correlated negatively with the IOP elevation. A multivariate analysis showed that average Schlemm canal vertical diameter (β = -0.262, P = .004) and trabecular meshwork thickness (β = -0.173, P < .001) were significantly associated with early transient IOP elevation in highly myopic cataract eyes.

CONCLUSIONS

A smaller vertical diameter of Schlemm canal and a thinner trabecular meshwork are 2 anatomic risk factors for early IOP elevation after cataract surgery in highly myopic eyes.

Changes of retinal and choroidal capillary blood flow in macula after an acute intraocular pressure elevation

The aim of this study was to investigate the changes of retinal vessel density (VD) and choriocapillary blood flow area (CBFA) in macula after an acute intraocular pressure (IOP) elevation observed using optical coherence tomography angiography.This was a prospective comparative study of subjects with narrow anterior chamber angles who underwent laser peripheral iridotomies (LPIs). The IOP was measured before and 1 hour after the LPI. The retinal VDs and CBFAs of the macula were measured using optical coherence tomography angiography at the baseline and 1 hour after the LPI.A total of 88 eyes of 88 individuals were enrolled in our study, and 70 eyes of 70 individuals finally completed the study with a mean IOP rise of 10.2 ± 7.5 mm Hg after the LPI. The VDs and areas of foveal avascular zone of all of the subjects did not differ significantly between the measurements obtained at the baseline and 1 hour after the LPI (P > .05). However, there were statistically significant differences in the CBFAs at the baseline and 1 hour after the LPI (P < .05). Based on the magnitude of the rise in the IOP, we divided the subjects into three groups: group A = IOP rise ≤ 10 mm Hg, group B = 10 mm Hg < IOP rise ≤20 mm Hg, and group C = IOP rise > 20 mmHg. The VDs of the macula measured at the baseline were significantly different from the measurements obtained 1 hour after the LPI in group C in either the superficial retinal layer or deep retinal layer (P < .05). Compared with baseline, the CBFAs measured at 1 hour after the LPI were decreased in group B and group C (P < .05).In these subjects with narrow antenior chamber, the blood flow in macula began to be affected with the acute IOP rise greater than 10 mm Hg. It was confirmed that the retina and choroid showed some different ability to regulate its blood flow in response to changes in IOP.

Intraocular pressure-lowering effect of omidenepag isopropyl in latanoprost non-/low-responder patients with primary open-angle glaucoma or ocular hypertension: the FUJI study

PURPOSE

Omidenepag isopropyl (OMDI) is the prodrug of omidenepag, a selective, non-prostaglandin, prostanoid EP2 receptor agonist, which has been shown to lower intraocular pressure (IOP) in patients with glaucoma and ocular hypertension (OHT). This study evaluated the efficacy and safety of OMDI ophthalmic solution 0.002% in patients with primary open-angle glaucoma or OHT who were non-/low responders to latanoprost.

STUDY DESIGN

Open-label, multicenter, Phase 3 study (NCT02822742).

METHODS

Following 1-4-week washout, patients were treated with latanoprost ophthalmic solution 0.005% during an 8-week run-in period. Patients with ≤15% IOP reduction at the end of the run-in (indicating non-/low response) received OMDI 0.002% (one drop once daily for 4 weeks). The primary endpoint was the change from baseline in mean diurnal IOP at Week 4.

RESULTS

In total, 26 patients were treated with OMDI; two withdrew owing to lack of efficacy. The mean diurnal IOP at baseline (end of latanoprost run-in) was 23.1 mmHg (7.6% IOP reduction from end of washout) indicating non-/low response to latanoprost. After 4 weeks of OMDI treatment, mean diurnal IOP was significantly reduced from baseline (-2.99 mmHg; P < 0.0001). No serious adverse events were reported. Adverse events occurred in five patients (19.2%); adverse drug reactions (anterior chamber cell, conjunctival hyperemia, and erythema of eyelid) occurred in two patients (7.7%) and were mild in severity.

CONCLUSIONS

In this study, OMDI 0.002% demonstrated a clinically significant reduction in IOP and was well tolerated in patients with primary open-angle glaucoma and OHT who were non-/low responders to latanoprost.

Bimatoprost Implant: First Approval

Bimatoprost implant (Durysta™), developed by Allergan, is a sustained-release drug delivery system containing bimatoprost, a prostaglandin analogue with ocular hypotensive activity. The implant, administered intracamerally, involves the use of a biodegradable, solid polymer drug delivery system for slow, sustained drug release, designed to lower intraocular pressure (IOP) over a 4- to 6-months period. In March 2020, bimatoprost implant received its first approval, in the USA, for use to reduce IOP in patients with open angle glaucoma (OAG) or ocular hypertension (OHT). Allergan's clinical development programme for bimatoprost implant is ongoing. This article summarizes the milestones in the development of bimatoprost implant leading to this first approval for use in the reduction of IOP in patients with OAG or OHT.

Efficacy of Repeat Selective Laser Trabeculoplasty in Medication-Naive Open-Angle Glaucoma and Ocular Hypertension during the LiGHT Trial

PURPOSE

To determine the efficacy of repeat selective laser trabeculoplasty (SLT) in medication-naive open-angle glaucoma (OAG) and ocular hypertensive (OHT) patients requiring repeat treatment for early to medium-term failure during the Laser in Glaucoma and Ocular Hypertension (LiGHT) trial.

DESIGN

Post hoc analysis of SLT treatment arm of a multicenter prospective randomized controlled trial.

PARTICIPANTS

Treatment-naive OAG or OHT requiring repeat 360-degree SLT within 18 months. Retreatment was triggered by predefined IOP and disease-progression criteria (using objective individualized target IOPs).

METHODS

After SLT at baseline, patients were followed for a minimum of 18 months after second (repeat) SLT. A mixed-model analysis was performed with the eye as the unit of analysis, with crossed random effects to adjust for correlation between fellow eyes and repeated measures within eyes. Kaplan-Meier curves plot the duration of effect.

MAIN OUTCOME MEASURES

Initial (early) IOP lowering at 2 months and duration of effect after initial and repeat SLT.

RESULTS

A total of 115 eyes of 90 patients received repeat SLT during the first 18 months of the trial. Pretreatment IOP before initial SLT was significantly higher than before retreatment IOP of repeat SLT (mean difference, 3.4 mmHg; 95% confidence interval [CI], 2.6-4.3 mmHg; P < 0.001). Absolute IOP reduction at 2 months was greater after initial SLT compared with repeat SLT (mean difference, 1.0 mmHg; 95% CI, 0.2-1.8 mmHg; P = 0.02). Adjusted absolute IOP reduction at 2 months (adjusting for IOP before initial or repeat laser) was greater after repeat SLT (adjusted mean difference, -1.1 mmHg, 95% CI, -1.7 to -0.5 mmHg; P = 0.001). A total of 34 eyes were early failures (retreatment 2 months after initial SLT) versus 81 later failures (retreatment >2 months after initial SLT). No significant difference in early absolute IOP reduction at 2 months after repeat SLT was noted between early and later failures (mean difference, 0.3 mmHg; 95% CI, -1.1 to 1.8 mmHg; P = 0.655). Repeat SLT maintained drop-free IOP control in 67% of 115 eyes at 18 months, with no clinically relevant adverse events.

CONCLUSIONS

These exploratory analyses demonstrate that repeat SLT can maintain IOP at or below target IOP in medication-naive OAG and OHT eyes requiring retreatment with at least an equivalent duration of effect to initial laser.

Structural Changes and Astrocyte Response of the Lateral Geniculate Nucleus in a Ferret Model of Ocular Hypertension

We investigated structural changes and astrocyte responses of the lateral geniculate nucleus (LGN) in a ferret model of ocular hypertension (OH). In 10 ferrets, OH was induced via the injection of cultured conjunctival cells into the anterior chamber of the right eye; six normal ferrets were used as controls. Anterograde axonal tracing with cholera toxin B revealed that atrophic damage was evident in the LGN layers receiving projections from OH eyes. Immunohistochemical analysis with antibodies against NeuN, glial fibrillary acidic protein (GFAP), and Iba-1 was performed to specifically label neurons, astrocytes, and microglia in the LGN. Significantly decreased NeuN immunoreactivity and increased GFAP and Iba-1 immunoreactivities were observed in the LGN layers receiving projections from OH eyes. Interestingly, the changes in the immunoreactivities were significantly different among the LGN layers. The C layers showed more severe damage than the A and A1 layers. Secondary degenerative changes in the LGN were also observed, including neuronal damage and astrocyte reactions in each LGN layer. These results suggest that our ferret model of OH is valuable for investigating damages during the retina–brain transmission of the visual pathway in glaucoma. The vulnerability of the C layers was revealed for the first time.

Non-contact determination of intra-ocular pressure in an ex vivo porcine model

People suffering from glaucoma often endure high intra-ocular pressure (IOP). Methods for determining IOP either contact the eye or are unpleasant to some patients. There is therefore a need for a rapid and patient friendly non-contacting method to determine IOP. To address this need, we developed a tonometer prototype that employs spark-gap induced shock waves and a laser Doppler vibrometer (LDV) that reads the amplitude of membrane waves. The IOP was first identified from the membrane wave propagation velocity first in a custom-made ocular phantom and was then verified in ex vivo porcine eyes. The time-of-flight (TOF) of the membrane wave travelling on a hemispherical membrane was compared to reference IOP values in the sample obtained with an iCare TA01 tonometer. The shock front was characterized by high speed photography. Within one eye, the method achieved an agreement of 5 mmHg (1.96 standard deviation between the shock wave tonometer and the commercial manometer) and high method-to-method association (Pearson correlation, R² = 0.98). The results indicate that the presented method could potentially be developed into a non-contacting technique for measuring IOP in vivo.

Ganglion Cell-Inner Plexiform Layer and Retinal Nerve Fiber Layer Changes in Glaucoma Suspects Enable Prediction of Glaucoma Development

PURPOSE

To investigate whether progressive macular ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) thinning predict development of visual field (VF) defects in glaucoma suspects.

DESIGN

Retrospective cohort study.

METHODS

This study included 541 eyes of 357 glaucoma suspects with a mean follow-up of 5.7 years. Progressive GCIPL and RNFL thinning were determined using Guided Progression Analysis (GPA) in optical coherence tomography (OCT). The development of VF defect was defined as the presence of three consecutive abnormal VFs. The risk of developing VF defect was evaluated using Cox proportional hazard models.

RESULTS

A total of 74 eyes (13.7%) and 87 eyes (16.1%) showed progressive GCIPL and RNFL thinning by OCT GPA, respectively, and 40 eyes (7.4%) developed VF defects. Eyes with progressive GCIPL (hazard ratio [HR], 7.130; 95% confidence interval [CI], 3.137-16.205) and RNFL (HR, 7.525; 95% CI, 3.272-17.311) thinning showed a significantly higher risk of developing VF defects. The rate of change in the average GCIPL and RNFL thickness was significantly higher in the eyes that developed VF defects (-0.71 and -1.13 μm/y, respectively) than the eyes that did not (-0.19 and -0.27 μm/y, respectively; all P < 0.05). Progressive GCIPL (43.1 vs. 63.1 months, respectively; P < 0.001) and RNFL (50.9 vs. 66.7 months, respectively; P < 0.001) thinning were detected significantly earlier than the development of VF defects.

CONCLUSIONS

Monitoring progressive change in GCIPL, as well as RNFL, effectively predicts the development of VF defects in glaucoma suspects.

A clinical method for estimating the modulus of elasticity of the human cornea in vivo

BACKGROUND

To develop a method, using current clinical instrumentation, to estimate the Young's modulus of the human cornea in vivo.

METHODS

Central corneal curvature (CCC), central corneal thickness(CCT), intraocular pressure (IOP) was measured with the Goldmann tonometer (IOPG) and the Pascal Dynamic Corneal Tonometer(PDCT) in one eye of 100 normal young human subjects (21.07 ± 2.94 years) in vivo. The Orssengo and Pye algorithm was used to calculate the Young's modulus of the corneas of these subjects.

RESULTS

The Young's modulus(E) of the corneas of the subjects using the PDCT and IOPG results (Ecalc) was 0.25 ± 0.10MPa, and without the PDCT results (Eiopg) was 0.29 ± 0.06MPa. The difference in these results is due to the difference in tonometry results between the two instruments, as the mean PDCT result for the subjects was 16.89 ± 2.49mmHg and the IOPG result 15.06 ± 2.71mmHg. E was affected by the CCC of the subjects but more particularly by the CCT and IOP measurements. Corneal stiffness results are also presented.

CONCLUSION

Two methods have been developed to estimate the Young's modulus of the human cornea in vivo using current clinical instrumentation. One method (Ecalc) is applicable to the general corneal condition, and Eiopg to the normal cornea, and these results can be used to calculate corneal stiffness.

Clinical Evaluation of Swedish Interactive Thresholding Algorithm-Faster Compared With Swedish Interactive Thresholding Algorithm-Standard in Normal Subjects, Glaucoma Suspects, and Patients With Glaucoma

PURPOSE

To compare the visual fields results obtained using the Swedish interactive thresholding algorithm-Standard (SS) and the Swedish interactive thresholding algorithm-Faster (SFR) in normal subjects, glaucoma suspects, and patients with glaucoma and to quantify potential time-saving benefits of the SFR algorithm.

DESIGN

Prospective, cross-sectional study.

METHODS

One randomly selected eye from 364 patients (77 normal subjects, 178 glaucoma suspects, and 109 patients with glaucoma) seen in a single institution underwent testing using both SS and SFR on the Humphrey Field Analyzer. Cumulative test time using each algorithm was compared after accounting for different rates of test reliability. Pointwise and cluster analysis was performed to determine whether there were systematic differences between algorithms.

RESULTS

Using SFR had a greater rate of unreliable results (29.3%) compared with SS (7.7%, P < .0001). This was mainly because of high false positive rates and seeding point errors. However, modeled test times showed that using SFR could obtain a greater number of reliable results within a shorter period of time. SFR resulted in higher sensitivity values (on average 0.5 dB for patients with glaucoma) that was greater under conditions of field loss (<19 dB). Cluster analysis showed no systematic patterns of sensitivity differences between algorithms.

CONCLUSIONS

After accounting for different rates of test reliability, SFR can result in significant time savings compared with SS. Clinicians should be cognizant of false positive rates and seeding point errors as common sources of error for SFR. Results between algorithms are not directly interchangeable, especially if there is a visual field deficit <19 dB.

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.

Prioritizing outcome preferences in patients with ocular hypertension and open-angle glaucoma using best-worst scaling

Purpose

To quantify patients' preferences for glaucoma outcomes and use this information to prioritize outcomes that are important to patients.

Design

A cross-sectional study using best-worst scaling object case (BWS).

Participants

Two hundred seventy-four participants newly diagnosed with ocular hypertension or mild to moderate open angle glaucoma from three private practices and one academic medical center in the United States.

Methods

We designed a preference-elicitation survey based on findings from 25 semi-structured, qualitative interviews with patients with glaucoma (reported elsewhere). The survey asked participants to rate the importance of 13 glaucoma outcomes on a Likert scale as a warm-up exercise followed by completion of 13 BWS tasks. For each task, we presented participants a subset of four outcomes from the possible thirteen, and participants chose the most important and least important outcome. Outcomes included in the survey pertain to maintaining ability to perform vision-dependent activities of daily living (e.g., driving), maintaining visual function and perception (e.g., depth perception), minimizing need to take glaucoma drops, not experiencing ocular surface symptoms (e.g., red eyes, teary eyes), and having adequate control of intraocular pressure (IOP). We administered the survey online and analyzed response patterns using conditional logistic regression to determine the relative importance of different outcomes.

Main outcome

Ordinal ranking of glaucoma outcomes based on preference weights.

Results

Between September 1, 2017 and February 28, 2018, we invited 1035 patients to complete our survey, among whom 274 (26%) responded. Most participants were older than 65 years of age (146/274, 53%) and currently on IOP-lowering drops (179/274, 65%). Participants identified that outcomes with the largest relative importance weight were having "adequate IOP control" and ability to "drive a car during the day," and the outcomes with the smallest relative importance weights were "maintaining appearance of the eye" and "reducing the number of IOP-lowering drops".

Conclusions

Determining the relative importance of glaucoma outcomes to patients can help researchers design studies that may better inform clinical and regulatory decision-making. Although IOP is an outcome that researchers often measure in glaucoma clinical trials, patients also prioritized outcomes related to the ability to perform vision-dependent activities such as driving.

Identifying outcomes that are important to patients with ocular hypertension or primary open-angle glaucoma: a qualitative interview study

Purpose

To explore patients' perspectives and experiences living with glaucoma and identify important benefits and risks that patients consider before electing for new glaucoma treatments, such as minimally invasive glaucoma surgical (MIGS) devices.

Design

Semi-structured, in-person qualitative interviews with patients seen at the Johns Hopkins Wilmer Eye Institute.

Participants

Adults older than 21 years of age who were suspected or diagnosed with ocular hypertension or mild to moderate primary open-angle glaucoma (POAG) (and thus eligible for treatment with a MIGS procedure) presenting to a glaucoma clinic in Baltimore, Maryland, between May and December 2016.

Method

We conducted in-person interviews with patients recently diagnosed with ocular hypertension or POAG. We focused on considerations patients take into account when deciding between different treatments. We used the framework approach to code and analyze the qualitative data. Considerations of special interest to us were those that can be translated into outcomes (or endpoints) in clinical trials.

Main outcome measures

Patients' perspectives concerning outcomes that matter to them when managing ocular hypertension or POAG.

Results

Ten male and fifteen female patients participated in our study. The median participant age was 69 years (range 47 - 82 years). We identified outcomes that patients expressed as important, which we grouped into four thematic categories: (1) limitations in performing specific vision-dependent activities of daily living; (2) problems with general visual function or perceptions; (3) treatment burden, including ocular adverse events; and (4) intraocular pressure (IOP). All 25 participants expressed some concerns with their ability to perform vision-dependent activities, such as reading and driving. Most (23/25) participants had an opinion about IOP, and among those currently taking ocular hypotensive eye drops, all recognized the relationship between eye drops and IOP.

Conclusion

We have identified outcomes that matter to patients who are deciding between different treatments for ocular hypertension and POAG, such as the ability to drive or maintain mobility outside the home. These outcomes will be important in future evaluations of new treatments for glaucoma.

Real-life experience of using brinzolamide/brimonidine fixed drop combination in a tertiary glaucoma centre

PURPOSE

To investigate the intraocular pressure (IOP)-lowering efficacy and tolerance of brinzolamide/brimonidine fixed combination (BBFC) under real-life conditions in a tertiary glaucoma centre.

METHODS

Medical records of all ocular hypertensive and open-angle glaucoma patients (n = 52) treated with BBFC were retrospectively analysed.

RESULTS

Thirty-nine patients had primary open-angle, 6 exfoliative, 2 pigment, 1 normal tension and 1 juvenile open-angle glaucoma and 3 ocular hypertension. The prior therapy was a prostaglandin analogue (PG) (n = 4), PG/timolol (n = 20), PG/timolol and topical carbonic anhydrase inhibitor (CAI; n = 19), timolol/CAI (n = 1), PG and CAI (n = 4), timolol/pilocarpine and PG (n = 1), timolol/brimonidine and PG (n = 1) and timolol/brimonidine, PG and CAI (n = 2). These were simplified to PG/timolol and BBFC (n = 41), PG and BBFC (n = 9), timolol and BBFC (n = 1) and timolol/pilocarpine, PG and BBFC (n = 1). The IOP on the study eyes was 21.2 ± 3.7 mmHg before and 16.9 ± 2.6, 16.0 ± 2.2, 17.6 ± 3.1 and 18.0 ± 3.1 mmHg after the introduction of BBFC at month 1, 3, 6 and 12, respectively (p < 0.0003 for all time points compared to baseline, p = 1.0 for all other comparisons). Thirty-one patients (59.6%) experienced no adverse event, 17 (32.7%) reported ocular and 6 (11.5%) systemic adverse events. BBFC therapy was terminated on 27 patients (51.9%): on 19 (36.5%) due to adverse events and on 8 (15.4%) due to insufficient IOP reduction.

CONCLUSION

In real-life practice, the introduction of BBCF allows significant and clinically meaningful IOP reduction and therapy simplification in glaucoma patients requiring complex medication, but in more than one third of the patients it is not tolerated due to adverse events.

The Relationship Between Scleral Strain Change and Differential Cumulative Intraocular Pressure Exposure in the Nonhuman Primate Chronic Ocular Hypertension Model

Purpose

To determine the relationship between peripapillary scleral strain change and cumulative differential IOP exposure in nonhuman primates (NHPs) with unilateral chronic ocular hypertension.

Methods

Posterior scleral shells from 6 bilaterally normal and 10 unilateral chronic ocular hypertension NHPs were pressurized from 5 to 45 mm Hg, and the resulting full-field, three-dimensional, scleral surface deformations were acquired using laser speckle interferometry. Scleral tensile strain (local tissue deformation) was calculated by analytical differentiation of the displacement field; zero strain was assumed at 5 mm Hg. Maximum principal strain was used to represent the scleral strain, and strains were averaged over a 15°-wide (∼3.6-mm) circumpapillary region adjacent to the ONH. The relative difference in mean strain was calculated between fellow eyes and compared with the differential cumulative IOP exposure within NHPs during the study period. The relationship between the relative difference in scleral strain and the differential cumulative IOP exposure in fellow eyes was assessed using an F test and quadratic regression model.

Results

Relative differential scleral tensile strain was significantly associated with differential cumulative IOP exposure in contralateral eyes in the chronic ocular hypertension NHPs, with the bilaterally normal NHPs showing no significant strain difference between fellow eyes. The sclera in the chronic ocular hypertension eyes was more compliant than in their fellow eyes at low levels of differential cumulative IOP exposure, but stiffer at larger differential IOPs (P < 0.0001).

Conclusions

These cross-sectional findings suggest that longitudinal IOP-induced changes in scleral mechanical behavior are dependent on the magnitude of differential cumulative IOP exposure.

Once-Daily Netarsudil Versus Twice-Daily Timolol in Patients With Elevated Intraocular Pressure: The Randomized Phase 3 ROCKET-4 Study

PURPOSE

To compare the intraocular pressure (IOP)-lowering efficacy and safety of netarsudil once daily (QD) and timolol twice daily (BID).

DESIGN

Double-masked, randomized, phase 3, noninferiority study.

METHODS

Patients with open-angle glaucoma or ocular hypertension (unmedicated baseline IOP >20 to <30 mm Hg at 8:00 AM) were randomized to netarsudil ophthalmic solution 0.02% QD (PM) or timolol ophthalmic solution 0.5% BID. The primary endpoint was mean IOP at 8:00 AM, 10:00 AM, and 4:00 PM at week 2, week 6, and month 3 in patients with baseline IOP <25 mm Hg (per-protocol population). Safety was recorded over the 6-month treatment period.

RESULTS

A total of 186 patients from each treatment arm were included in the primary efficacy analysis. Netarsudil QD met the criteria for noninferiority to timolol BID. Mean treated IOP ranged from 16.3 to 17.9 mm Hg for netarsudil and 16.7 to 17.6 for timolol, with mean reductions from baseline of 3.9 to 4.7 mm Hg and 3.8 to 5.2 mm Hg, respectively. In prespecified secondary analyses, netarsudil demonstrated noninferiority to timolol in patients with baseline IOP <27 mm Hg and <30 mm Hg. The IOP-lowering effects of netarsudil were sustained over 6 months of treatment. No treatment-related serious adverse event (AE) was reported for either study drug. However, statistically significant reductions in mean heart rate were recorded at all study visits for the timolol group. The most frequent ocular AE among netarsudil-treated patients was conjunctival hyperemia (47.9%), which was predominately mild.

CONCLUSIONS

Netarsudil QD (PM), a first-in-class IOP-lowering medication, was noninferior to timolol BID and was associated with tolerable ocular AEs.

The Genetic Influence on Corticosteroid-Induced Ocular Hypertension: A Field Positioned for Discovery

PURPOSE

To provide evidence that corticosteroid-induced ocular hypertension has a genetic component.

DESIGN

Evidence-based perspective.

METHODS

We conducted a comprehensive literature search for studies exploring genetic influences on intraocular pressure responses to corticosteroid treatment.

RESULTS

Studies demonstrating increased risk of corticosteroid-induced ocular hypertension among first-degree relatives of affected individuals support a genetic contribution to the disease. Family and personal history of primary open-angle glaucoma also increases the risk of corticosteroid-induced intraocular pressure elevation, suggesting common genetic etiologies. A number of studies have attempted to identify predisposing genetic factors; however, reproducible findings have not yet been reported. The recent availability of large data sets with clinical and genetic data for patients affected by corticosteroid-induced ocular hypertension and glaucoma provides new opportunities to study the genetic underpinnings of this important condition.

CONCLUSIONS

There is substantial evidence suggesting a genetic component to corticosteroid-related ocular hypertension and glaucoma, but specific genetic risk factors have yet to be identified. The current confluence of large genetic data sets and affordable genetic sequencing technologies has great potential for discovering the genes that increase risk for this blinding complication of corticosteroid therapy.

Noninferiority of Preservative-free Versus BAK-preserved Latanoprost-timolol Fixed Combination Eye Drops in Patients With Open-angle Glaucoma or Ocular Hypertension

PRéCIS:: Noninferiority of efficacy was demonstrated for a preservative-free latanoprost-timolol fixed combination compared with a BAK-containing formulation at 84 days after treatment in patients with open-angle glaucoma or ocular hypertension.

PURPOSE

The purpose of this study was to compare the effect on intraocular pressure and safety of preservative-free latanoprost-timolol fixed combination (T2347) to benzalkonium chloride-preserved latanoprost-timolol fixed combination in patients with open-angle glaucoma or ocular hypertension.

METHODS

Phase III, randomized, parallel-group, investigator-masked study in 10 countries. A total of 242 patients aged 18 years or older with open-angle glaucoma or ocular hypertension in both eyes controlled with a preserved latanoprost-timolol fixed combination (15.7±2.4 mm Hg overall before inclusion) were randomized at day 0 with no washout period to receive the preservative-free alternative T2347 (N=127) or remain on the preserved comparator (N=115) for 84 days. Intraocular pressure changes from day 0 were measured at 9:00 am (±1 hour) on day 42 and day 84, and noninferiority of T2347 to the preserved comparator was analyzed statistically at day 84. Safety parameters were also reported.

RESULTS

The mean change in intraocular pressure from baseline to day 84 was -0.49±1.80 mm Hg for preservative-free T2347 and -0.49±2.25 mm Hg for the preserved comparator. These results met the noninferiority limits. Similar results were observed at day 42. There was no difference between groups in the incidence of adverse events or ocular signs. The total ocular symptoms score was better for T2347 than BPLT upon instillation at day 84 (45.9%/44.3%/9.8% of patients with improvement/no change/worsening vs. 33.6%/47.3%/19.1%; P=0.021), reflecting improvements in individual symptoms such as irritation/burning/stinging (P<0.001), and itching (P<0.01) on day 84.

CONCLUSIONS

Preservative-free latanoprost-timolol fixed combination T2347 showed noninferior efficacy compared with the preserved comparator and was well tolerated.

Long-term Safety and Ocular Hypotensive Efficacy Evaluation of Netarsudil Ophthalmic Solution: Rho Kinase Elevated IOP Treatment Trial (ROCKET-2)

PURPOSE

To evaluate netarsudil 0.02% ophthalmic solution in patients with open-angle glaucoma (OAG) and ocular hypertension (OHT).

DESIGN

Double-masked, randomized, multicenter, parallel-group, noninferiority clinical study.

METHODS

After a washout of all prestudy ocular hypotensive medications, 756 eligible patients with elevated IOP were randomized to receive netarsudil 0.02% once a day (q.d.) (251); netarsudil 0.02% twice a day (b.i.d.) (254); or timolol 0.5% b.i.d. (251) for 12 months, as well as a noninterventional Corneal Observation Study (COS) for patients manifesting cornea verticillata.

RESULTS

On treatment, mean IOP at 8:00 AM decreased from a baseline IOP of 22.5-22.6 mm Hg to 17.9-18.8 mm Hg, 17.2-18.0 mm Hg, and 17.5-17.9 mm Hg for netarsudil q.d., netarsudil b.i.d., and timolol, respectively, over 12 months. The most frequently reported adverse events (AEs) were ocular, with the most frequent ocular AE being conjunctival hyperemia, with an incidence of 61%, 66%, and 14%, respectively. The next most frequent AEs were corneal deposits (corneal verticillata), with an incidence of 26%, 25%, and 1%, respectively, and conjunctival hemorrhage (typically petechial), with an incidence of 20%, 19%, and 1%, respectively. All 3 AEs were generally scored as mild, with conjunctival hyperemia and/or hemorrhage appearing sporadically during the study. In the observational follow-up component of this study, there was no clinically meaningful impact of corneal verticillata on visual function in affected patients.

CONCLUSIONS

In this randomized, double-masked trial, once-daily dosing of netarsudil 0.02% was effective, consistently lowering IOP through 12 months, and was tolerated by the majority of patients.

A Novel Synthetic Steroid of 2β,3α,5α-Trihydroxy-androst-6-one Alleviates the Loss of Rat Retinal Ganglion Cells Caused by Acute Intraocular Hypertension via Inhibiting the Inflammatory Activation of Microglia

Neuroinflammation has been well recognized as a key pathological event in acute glaucoma. The medical therapy of acute glaucoma mainly focuses on lowering intraocular pressure (IOP), while there are still scarce anti-inflammatory agents in the clinical treatment of acute glaucoma. Here we reported that β,3α,5α-trihydroxy-androst-6-one (sterone), a novel synthetic polyhydric steroid, blocked neuroinflammation mediated by microglia/macrophages and alleviated the loss of retinal ganglion cells (RGCs) caused by acute intraocular hypertension (AIH). The results showed that sterone significantly inhibited the morphological changes, the up-regulation of inflammatory biomarker ionized calcium-binding adapter molecule 1 (Iba-1), and the mRNA increase of proinflammatory tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) induced by lipopolysaccharide (LPS) in BV2 microglia and RAW264.7 macrophages. Moreover, immunofluorescence and western blotting analysis revealed that sterone markedly abrogated the nuclear translocation and phosphorylation of nuclear factor-κB (NF-κB) p65 subunit. Furthermore, sterone significantly suppressed the inflammatory microglial activation and RGCs’ reduction caused by retinal ischemia/reperfusion (I/R) injury in a rat AIH model. These results suggest sterone may be a potential candidate in the treatment of acute glaucoma caused by microglial activation-mediated neuroinflammatory injury.

Long-term probability of intraocular pressure elevation with the intravitreal dexamethasone implant in the real-world

PURPOSE

To evaluate the long-term cumulative probability of intraocular pressure (IOP) elevation with the intravitreal dexamethasone implant (IDI) when used to treat different indications: diabetic macular edema, uveitis, retinal vein occlusion.

METHODS

705 IDI injections (429 eyes) were assessed and Kaplan-Meier graphs were generated to assess: the probability of different levels of IOP elevation (IOP≥21, ≥25 or ≥35 mmHg), IOP change ≥10 mmHg, initiation of IOP-lowering treatment, glaucoma surgery, IOP change with repeat injections and IOP elevation in eyes with glaucoma and ocular hypertension (OHT).

RESULTS

The cumulative probability of IOP ≥21, ≥25 and ≥35 mmHg was 50%-60%, 25%-30% and 6%-7% at 12-24 months, respectively. The probability of initiating IOP-lowering medication was 31%-54% at 12-24 months. Glaucoma and OHT eyes had a higher probability of mild IOP elevation (≥21 mmHg, 65.1%, 75% and 57.8%, p = 0.01), yet a similar moderate (≥25 mmHg, 22.3%, 28% and 30.2%, p = 0.91) and severe elevation of IOP (≥35 mmHg, 3.7%, 7.1% and 4%, p = 0.71) as normal eyes. Glaucoma surgery was required in only 0.9% cases (4/429). At baseline, 8.8% of the treated eyes had glaucoma, 6.7% OHT and 16.9% were already on IOP-lowering medication.

CONCLUSIONS

In the long-term (24 months), IOP elevation is common, generally mild (30% IOP, ≥25 mmHg) and well-tolerated, resolving with topical treatment (54%) and rarely requiring surgery (0.9%).

Evaluating changes of blood flow in retina, choroid, and outer choroid in rats in response to elevated intraocular pressure by 1300 nm swept-source OCT

We report the development of a 1300 nm swept-source optical coherence tomography (SS-OCT) system specifically designed to perform OCT imaging and optical microangiography (OMAG) in rat eyes in vivo and its use in evaluating the effects of intraocular pressure (IOP) elevation on ocular circulation. The swept laser is operated in single longitude mode with a 90 nm bandwidth centered at 1300 nm and 200 kHz A-line rate, providing remarkable sensitivity fall-off performance along the imaging depth, a larger field of view of 2.5 × 2.5 mm2 (approximately 35°), and more time-efficient imaging acquisition. The advantage of the SS-OCT/OMAG is highlighted by an increased imaging depth of the entire posterior thickness of optic nerve head (ONH) and its surrounding vascular anatomy, to include, for the first time in vivo, the vasculature at the scleral opening, allowing visualization of the circle of Zinn-Haller and posterior ciliary arteries (PCAs). Furthermore, the capillary-level resolution angiograms achieved at the retinal and choroidal layers over a larger field of view enable a significantly improved quantification of the response of vascular area density (VAD) to elevated IOP. The results indicate that reduction in perfusion of the choroid in response to elevated IOP is delayed compared to that seen in the retina; while choroidal VAD doesn't reach 50% of baseline until ~70 mmHg, the same effect is seen for the retinal VAD at ~60 mmHg. The superior image quality offered by SS-OCT may allow more comprehensive investigation of IOP-related ocular perfusion changes and their pathological roles in glaucomatous optic nerve damage.