Intraocular pressure changes related to intravitreal injections of ranibizumab: analysis of pseudophakia and glaucoma subgroup

The Inflammasome-Dependent Dysfunction and Death of Retinal Ganglion Cells after Repetitive Intraocular Pressure Spikes

The dysfunction and selective loss of retinal ganglion cells (RGCs) is a known cause of vision loss in glaucoma and other neuropathies, where ocular hypertension (OHT) is the major risk factor. We investigated the impact of transient non-ischemic OHT spikes (spOHT) on RGC function and viability in vivo to identify cellular pathways linking low-grade repetitive mechanical stress to RGC pathology. We found that repetitive spOHT had an unexpectedly high impact on intraocular homeostasis and RGC viability, while exposure to steady OHT (stOHT) of a similar intensity and duration failed to induce pathology. The repetitive spOHT induced the rapid activation of the inflammasome, marked by the upregulation of NLRP1, NLRP3, AIM2, caspases -1, -3/7, -8, and Gasdermin D (GSDMD), and the release of interleukin-1β (IL-1β) and other cytokines into the vitreous. Similar effects were also detected after 5 weeks of exposure to chronic OHT in an induced glaucoma model. The onset of these immune responses in both spOHT and glaucoma models preceded a 50% deficit in pattern electroretinogram (PERG) amplitude and a significant loss of RGCs 7 days post-injury. The inactivation of inflammasome complexes in Nlrp1-/-, Casp1-/-, and GsdmD-/- knockout animals significantly suppressed the spOHT-induced inflammatory response and protected RGCs. Our results demonstrate that mechanical stress produced by acute repetitive spOHT or chronic OHT is mechanistically linked to inflammasome activation, which leads to RGC dysfunction and death.

Evaluation of short-term intraocular pressure changes after intravitreal injection of Conbercept in patients with diabetic macular edema

Background: The study concerning the influence of Conbercept, which is an anti-Vascular endothelial growth factor (VEGF) agent, in intraocular pressure (IOP) spike is limited and warrants further investigation. The current study aimed to investigate the changes of intraocular pressure after intravitreal injection (IVI) of Conbercept and evaluate the risk factors associated with intraocular pressure spikes. Methods: Patients with diabetic macular edema receiving intravitreal injection of 0.05 ml (0.5 mg) Conbercept were involved in the study. All patients underwent slit lamp examination to determine the status of phakia/pseudophakia. The axial length was measured using IOL Master 500 before intravitreal injection. Patients underwent a Conbercept intravitreal injection with a 30-gauge needle in a standard fashion. The intraocular pressure was measured 2 min before injection, and 2, 10, 30 min, 1, 2, 5, 24 h after injection using a rebound tonometer. The changes of intraocular pressure and the relevant risk factors were evaluated. Patients were subdivided into phakic group and pseudophakic group to analyze the effect of lens status on intraocular pressure changes. Results: Forty patients with a mean age of 62.48 ± 12.22 years were included in the study. The mean intraocular pressure values at baseline and 2, 10, 30 min, 1, 2, 5, 24 h after injection were 14.81 ± 3.13 mmHg, 26.80 ± 9.43 mmHg, 18.76 ± 6.16 mmHg, 16.54 ± 5.94 mmHg, 15.64 ± 3.75 mmHg, 14.46 ± 3.03 mmHg, 14.10 ± 1.88 mmHg, 14.23 ± 2.71 mmHg respectively. The intraocular pressure after injection for 2, 10 min was significantly higher than baseline (p < 0.001, p = 0.001, respectively). The intraocular pressure between baseline and post-injection for 30 min or beyond were comparable (all p > 0.05). No significant difference was found between the phakic group and pseudophakic group (p = 0.422). The changes of intraocular pressure were positively correlated with age (r = 0.329, p = 0.038), but negatively with axial length (r = -0.472, p = 0.002). Conclusion: intravitreal injection of Conbercept may cause rapid spike of intraocular pressure, but is safe with respect to short-term changes. The intraocular pressure in patients with older age and shorter axial length is more likely to be higher after intravitreal injection.

Risk, Prevalence, and Progression of Glaucoma in Eyes With Age-Related Macular Degeneration Treated With Intravitreal Anti-Vascular Endothelial Growth Factor Injections

PURPOSE

To examine the risk, prevalence, and progression of glaucoma development in age-related macular degeneration (AMD) eyes receiving intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections compared to controls.

DESIGN

Retrospective clinical cohort study.

METHODS

Retrospective review of eyes receiving intravitreal anti-VEGF injections from January 1, 2004, to December 31, 2013, for exudative AMD. Age- and sex-matched control groups of eyes included eyes with nonexudative AMD (NEAMD) and no AMD. Eyes with a diagnosis of glaucoma or glaucoma suspect were reviewed for injection details, type and date of glaucoma diagnosis, glaucoma treatments, standard automated perimetry (SAP), and spectral domain optical coherence tomography (SD-OCT). Qualitative progression was determined by indication of glaucoma progression in provider notes. Quantitative progression was assessed based on change in mean deviation (MD) on SAP, retinal nerve fiber layer thickness on SD-OCT, and intraocular pressure (IOP).

RESULTS

There were 707 eyes of 504 patients treated with anti-VEGF injections and 1008 eyes in the NEAMD and no-AMD cohorts. There was no difference in glaucoma or suspect prevalence at initial presentation between eyes treated with injections and NEAMD (6.9% vs 9.7%, P = .22) or no-AMD controls (vs 8.5%, P = .55). There was no difference in cumulative 5-year probability of new glaucoma diagnosis after anti-VEGF injections compared to NEAMD (1.9% vs 1.0%, P = .69) or no-AMD controls (vs 1.6%, P = .88). There was no difference in qualitative progression of glaucoma in the injection cohort vs NEAMD (P = .19) or no-AMD controls (P = .61). The rate of MD change in injection eyes was similar to NEAMD eyes (P = .74) but greater than no-AMD eyes (P = .02). Eyes receiving injections required more topical glaucoma medications compared with NEAMD (P = .03) and more glaucoma laser treatments compared with no-AMD controls (P = .009). Eyes receiving injections did not require more frequent incisional glaucoma surgery compared with NEAMD (21.0% vs 15.0%, P = .95) or no-AMD controls (vs 10.0%, P = .10).

CONCLUSION

Eyes treated with intravitreal anti-VEGF injections for exudative AMD did not have increased risk of developing glaucoma compared with controls. Of those with a glaucoma diagnosis, exudative AMD eyes receiving injections required a greater number of topical glaucoma medications compared with NEAMD eyes and had a greater rate of MD loss than no-AMD controls.

The effects of intravitreal injections on intraocular pressure and retinal nerve fiber layer: a systematic review and meta-analysis

The number of eye diseases treated with intravitreal injections is increasing. Obviously, an injection of fluid into the eye results in an increase of intraocular pressure (IOP), the main risk factor for glaucoma. However, the effect of these repeated IOP increases on the eye is unclear. Therefore, we performed a systematic review with meta-analyses. PubMed, Embase and Clinical Trials Registries were searched for articles investigating the relationship between intravitreal injections (anti-vascular endothelial growth factor [anti-VEGF] or steroids) and either IOP, retinal nerve fiber layer (RNFL)-thickness and glaucoma. Multiple meta-analyses were performed, combining data on intravitreal injection of anti-VEGF medication and dexamethasone implants. A total of 74 articles were eligible for meta-analyses. The short-term effect of an intravitreal injection of anti-VEGF showed a statistically significant increase in IOP. One day after injection of anti-VEGF, however, IOP was significantly lower than baseline. The long-term time-intervals showed no significant difference in IOP. After intravitreal injection of a dexamethasone implant, IOP was significantly higher than baseline 1 month post-injection. RNFL-thickness was significantly reduced 6 and 12 months post-injection of anti-VEGF, as well as at end of follow up. Caution is advised when using intravitreal medication, especially when treating patients with advanced glaucoma; in these cases, prophylactic IOP-lowering medication may be considered.

Effects of Intravitreal Anti-VEGF Therapy on Glaucoma-like Progression in Susceptible Eyes

PRéCIS:: Intravitreal anti-vascular endothelial growth factor (VEGF) injections may accelerate glaucomatous change in patients with preexisting glaucoma or ocular hypertension (OHT). The safety of long-term injections in this specific population may be reflected in the need for additional glaucoma interventions.

PURPOSE

The purpose of this study was to investigate whether repeated anti-VEGF injections accelerate structural and functional glaucomatous change in eyes with preexisting glaucoma or OHT.

MATERIALS AND METHODS

This is a retrospective, observational study of injected and noninjected fellow eyes. A total of 28 patients with preexisting glaucoma or OHT, who received ≥6 unilateral anti-VEGF injections for concurrent neovascular retinal disease, were selected for chart review. Primary outcome measures were rate of visual field loss in dB/year, rate of change in retinal nerve fiber layer (RNFL) thickness in microns/year, and need for additional glaucoma medications, surgery, or laser.

RESULTS

The number of eyes requiring additional glaucoma surgery or laser was 8 of 28 (28.6%) for the injected group and 2 of 28 (7.1%) for the noninjected group. A significantly greater proportion of injected eyes required invasive glaucoma intervention (P=0.034). Average rate of decline in mean deviation and change in pattern standard deviation were both significantly greater in injected eyes (P=0.029; P=0.019). Estimated mean rate of global retinal nerve fiber layer change was -4.27 µm/y for the injected group and -1.17 µm/y for the noninjected group and was significant only for injected eyes (P=0.014). Only the superior quadrant exhibited thinning that was significantly different between groups (P=0.030).

CONCLUSIONS

Intravitreal injections were associated with accelerated functional and structural glaucoma-like change in susceptible eyes. Clinicians should assess the need for glaucoma medications or other interventions over the course of anti-VEGF therapy.

Vitreous Reflux Frequency and Intraocular Pressure After First-Time Intravitreal Aflibercept Injections: Comparison of 30- and 32-Gauge Needles

Purpose

To compare the effects of 30-gauge versus 32-gauge needles on vitreous reflux (VR) frequency and intraocular pressure (IOP) following first-time intravitreal aflibercept injections.

Materials and Methods

Overall, 116 patients (116 eyes) who received intravitreal injections using 30-gauge needles and 104 patients (104 eyes) who received the same injection using 32-gauge needles were reviewed. The medical records of 116 patients who each received an intravitreal injection using a 30-gauge needle (median age: 67.5 ± 13.9 years) and 104 patients who each received the same injection using a 32-gauge needle (median age: 66. 3 ± 10.6 years) from January 2015 to June 2019 were compared.

Results

No significant difference in the frequency of VR was observed between patients injected using 30-gauge needles (38/116) and patients injected using 32-gauge needles (31/104, P = 0.64). There were no significant differences in the VR rates of patients with phakic and pseudophakic eyes between those injected using 30-gauge (P = 0.94) or 32-gauge needles (P = 0.77). Axial length did not significantly differ between patients with and without VR when injected using 30-gauge (P = 0.89) and with 32-gauge needles (P = 0.69). IOP immediately after injection was significantly higher in patients injected using 30-gauge needles than in patients injected using 32-gauge needles (P < 0.01).

Conclusion

VR frequency was not correlated with needle size, lens status, or axial length. Patients receiving injections using 30-gauge needles had higher IOP immediately after intravitreal injection.

The acute and chronic effects of intravitreal anti-vascular endothelial growth factor injections on intraocular pressure: A review

The acute and chronic effects of repeated intravitreal antivascular endothelial growth factor (VEGF) injections on intraocular pressure have not been fully characterized, and the development of sustained ocular hypertension could adversely affect patients who are at risk of glaucomatous optic neuropathy. As expected, volume-driven, acute ocular hypertension immediately follows intravitreal injection, but this pressure elevation is generally transient and well tolerated. Several medications have been investigated to limit acute ocular hypertension following anti-VEGF therapy, but the benefits of pretreatment are not conclusive. Chronic, sustained ocular hypertension, distinct from the short-term acute ocular hypertension after each injection, has also been associated with repeated intravitreal anti-VEGF injections. Risk factors for chronic ocular hypertension include the total number of injections, a greater frequency of injection, and preexisting glaucoma. Proposed mechanisms for chronic ocular hypertension include microparticle obstruction, toxic or inflammatory effects on trabecular meshwork, as well as alterations in outflow facility by anti-VEGF agents. Although limiting anti-VEGF therapy could minimize the risk of both acute and chronic ocular hypertension, foregoing anti-VEGF therapy risks progression of various macular diseases with resulting permanent central vision loss. While definitive evidence of damage to the retinal nerve fiber layer is lacking, patients receiving repeated injections should be monitored for ocular hypertension and patients in whom sustained ocular hypertension subsequently developed should be periodically monitored for glaucomatous changes with optic nerve optical coherence tomography and static visual fields.

A minimally invasive adjustable-depth blunt injector for delivery of pharmaceuticals into the posterior pole

PURPOSE

To investigate the feasibility and safety of a novel minimally invasive adjustable-depth blunt injector for pharmaceuticals delivery into the posterior segment.

METHODS

Indocyanine green (ICG), sodium fluorescein and iron oxide nanoparticles (IONPs) were injected using the new injector into the extravascular spaces of the choroid (EVSC) compartment of rabbits and cadaver pig eyes. Spectral domain optical coherence tomography (SD-OCT), fundus imaging and histology analysis were performed for assessment of injection safety and efficacy.

RESULTS

Indocyanine green, fluorescein and IONPs were detected across the EVSC in rabbit eyes, covering over 80 per cent of the posterior eye surface. Injected IONPs were retained in the EVSC for at least 2 weeks following injection. No retinal detachment, choroidal haemorrhage or inflammation was detected in any of the injected eyes. In cadaver pig eyes, ICG was detected across the EVSC.

CONCLUSIONS

This novel minimally invasive delivery system may be used to safely deliver large volumes of pharmaceuticals into a new treatment reservoir compartment - the EVSC which can serve as a depot, in close proximity to the retina, covering most of the surface of the back of the eye without insertion of surgical instruments under the central retina. This system is predicted to enhance the therapeutic effect of treatments for posterior eye disorders.

INTRAOCULAR PRESSURE IN PATIENTS WITH DIABETIC MACULAR EDEMA TREATED WITH DEXAMETHASONE INTRAVITREAL IMPLANT IN THE 3-YEAR MEAD STUDY

PURPOSE

To evaluate the occurrence, management, and clinical significance of increases in intraocular pressure (IOP) in patients with diabetic macular edema treated with dexamethasone intravitreal implant (DEX implant).

METHODS

Randomized, multicenter, 3-year, Phase III study. Patients (N = 1,048) with diabetic macular edema were randomized to DEX implant 0.7-mg, DEX implant 0.35-mg, or sham procedure with retreatment allowed at ≥6-month intervals (seven injections maximum).

RESULTS

In the DEX implant 0.7-mg, DEX implant 0.35-mg, and sham groups, respectively, ≥10-mmHg IOP increases from baseline occurred in 27.7%, 24.8%, and 3.7% of patients, and their frequency did not increase with repeat injections. IOP-lowering medication was used by 41.5%, 37.6%, and 9.1% of patients. Only one patient (0.3%) in each DEX implant group had filtering surgery to manage a steroid-induced IOP increase. Among DEX implant 0.7-mg-treated patients with and without a ≥10-mmHg IOP increase, 21.9% (21 of 96) and 22.4% (57 of 255), respectively, achieved ≥15-letter best-corrected visual acuity gain at the end of the study, and mean average change in central retinal thickness from baseline was -127 μm and -106 μm, respectively.

CONCLUSION

DEX implant demonstrated clear benefit of treatment despite increases in IOP. Sequential implants had no cumulative effect on IOP.

Ranibizumab versus bevacizumab for the treatment of idiopathic choroidal neovascularization: 2-Year results

PURPOSE

To compare the efficacy and safety of bevacizumab vs ranibizumab for the treatment of idiopathic choroidal neovascularization (ICNV).

METHODS

This retrospective study included 60 eyes of 60 patients with ICNV who underwent intravitreal injection of bevacizumab (1.25 mg/0.05 mL, n = 30 eyes) or ranibizumab (0.5 mg/0.05 mL, n = 30 eyes). Multiple treatments were based on complete ophthalmologic investigation including slit-lamp biomicroscopy, fundus examination, fundus fluorescein angiography (FFA), optical coherence tomography (OCT), and best-corrected visual acuity (BCVA). The BCVA, central retinal thickness (CRT), intraocular pressure (IOP), FFA results, and complications were compared between the 2 groups during the 2-year follow-up.

RESULTS

Visual acuity was significantly better at 1, 3, 6, 12, and 24 months after treatment (p&lt;0.01), with no significant difference in visual acuity between the bevacizumab and ranibizumab groups. In both groups of patients, the CRT after treatment was significantly less than before. At 12 and 24 months, the CRT in the ranibizumab group was significantly less than in the bevacizumab group (p&lt;0.05). The FFA examination showed that CNV was reduced after intravitreal injection of either drug, with no significant difference in IOP between the 2 groups. No ophthalmologic or systemic complications occurred.

CONCLUSIONS

Bevacizumab and ranibizumab are effective and safe in the treatment of ICNV, with similar effects in improving visual acuity and reducing retinal edema. The long-term efficacy of ranibizumab is superior to bevacizumab in reducing CRT.