Intraocular Pressure Changes in Non-Glaucomatous Patients Receiving Intravitreal Anti-Vascular Endothelial Growth Factor Agents

Immediate Rise in Intraocular Pressure After First-Time Intravitreal Injection of Bevacizumab

Objective This study aims to report an immediate change in intraocular pressure (IOP) after the first injection of bevacizumab. Materials and methods An interventional case series was carried out at Isra Postgraduate Institute of Ophthalmology, Al-Ibrahim Eye Hospital, Karachi, from November 2018 to April 2020. All patients with various chorioretinal diseases requiring anti-VEGF treatment were included in the study. Patients with a history of previous anti-VEGF or steroid injections and personal or family history of glaucoma were excluded. Bevacizumab in a dose of 1.25 mg (0.05 ml) was injected intravitreally under topical anesthesia maintaining sterile aseptic conditions in the operating room. IOP was checked one hour prior to the injection, and hourly monitoring of it was continued for the next six hours. Data were analyzed using SPSS Statistics to compare the mean IOP readings before and after injection. Results A total of 191 eyes of 147 patients were included in the study. Among them, 92 (62.58%) were male and 55 (37.41%) were female with a mean age of 45.5 ± 8.8 years. The mean pre-injection IOP was measured as 12.12 ± 2.11 mmHg. The frequency of IOP elevation of ˃ 21 mmHg was observed in 169 (88.5%) eyes at five minutes, 104 (54.5%) eyes at 30 minutes, 33 (17.3%) eyes at one hour, and 16 (8.4%) eyes at two hours. The raised mean post-operative IOP was 30.44 ± 6.53 mmHg at five minutes, 26.27 ± 4.65 mmHg at 30 minutes, 26.12 ± 3.31 mmHg at one hour, and 25.63 ± 3.03 mmHg at two hours. The IOP reduced to pre-injection value at three hours measuring 12.12 ± 2.11 mmHg and continued to stay at that level for the next three hours. Conclusions The majority of the eyes receiving first-time intravitreal bevacizumab injection showed a significant increase in IOP level within five minutes to two hours post-injection.

Comparison of Syringes With Intravitreal Anti-VEGF Drugs: Particle Burden and Protein Aggregates in Brolucizumab, Aflibercept and Bevacizumab

Purpose

In a benchwork particle counting analytical evaluation, the number and type of particles in intravitreal injection formulations of three different agents against vascular endothelial growth factor were investigated.

Methods

Commercially available ready-to-use aflibercept and brolucizumab glass syringes, vials containing bevacizumab (off-label use in ophthalmology), and repackaged ready-to-use plastic syringes containing bevacizumab were tested without filtration. Total visible, subvisible, and nanoparticles numbers and size distributions were quantified using light obscuration, flow imaging, resonant mass measurement (RMM), tunable resistive pulse sensing, and dynamic light scattering.

Results

Repackaged bevacizumab showed overall low particle numbers, aflibercept showed high numbers of micrometer sized particles but low nanoparticle numbers, brolucizumab showed low to moderate numbers of micrometer sized particles but high nanoparticle numbers. RMM measurements identified particles in the nanometer range as either proteinaceous or silicon oil; the nature of the other particles was not further evaluated.

Conclusions

Repackaged bevacizumab shows no inferior particle quality compared to ready-to-use products. It is relevant to study nanoparticle load of the products as the micrometer-sized particle numbers do not in all cases correlate to nanoparticle counts. Particularly for the high concentration product Beovu (brolucizumab), high nanoparticle numbers were found despite low numbers of micrometer sized particles. Silicone oil droplets did not account for high particle numbers as the measured numbers were low.

Translational Relevance

Different side effects are registered in different frequencies with different intravitreal anti-VEGF-drugs and syringes, which are applied by injection by small 30G needles through the sclera directly to the intravitreal cavity. The study of nanoparticles and silicone oil droplets may be able to contribute to narrowing down the causes.

Effect of Intravitreal Injections on Retinal Imaging Metrics in Glaucomatous and Non-Glaucomatous Eyes

Purpose of Review

To summarize the available literature on retinal imaging metrics in the context of intravitreal injections in glaucomatous and non-glaucomatous eyes.

Recent Findings

The retinal nerve fiber layer (RNFL) in injected non-glaucomatous eyes appears to thin at a similar rate to uninjected fellow eyes. A total of four studies evaluating RNFL thinning in injected glaucomatous eyes yielded mixed results, with more recent longitudinal investigations suggesting a potential association. The ganglion cell-inner plexiform layer is also being studied as a potential endpoint in both glaucomatous and non-glaucomatous eyes following intravitreal injections.

Issues with Intravitreal Administration of Anti-VEGF Drugs

Purpose

To provide an update of summary of risk factors and side effects of long-term use and contamination of intravitreal anti-VEGF injections.

Methods

We reviewed relevant publications of the topic of contamination of anti-VEGF injections and long-term side effects due to this reason.

Results

Due to the long-term use of anti-VEGF drugs and the higher number of injections worldwide, various studies have shown side effects in recent years, ranging from increased intraocular pressure to visual disturbing silicone oil vesicles in the vitreous cavity. Several studies have demonstrated that both the drug and the processing, storage, environmental factors and the material and design of the syringes have a decisive influence on these side effects.

Conclusion

The risks of deposits from syringes in the eye can be significantly reduced by various optimizations in transport, storage and syringe and cannula selection.

Incidence of ocular hypertension after intravitreal injection of anti-VEGF agents in the treatment of neovascular AMD

Purpose. The assessment of the incidence of ocular hypertension over a period of 1 year in patients treated with multiple intravitreal injections of anti-VEGF agents for neovascular AMD.

Methods. The study comprised 58 eyes diagnosed with neovascular age-related macular degeneration and receiving PRN intravitreal treatment with anti-VEGF agents (bevacizumab or aflibercept). The follow-up period was 1 year. Intraocular pressure was measured by using the Goldmann applanation tonometry before the intravitreal injection, at 24 hours after the administration of the anti-VEGF agent and at 1 and 4 weeks. Patients diagnosed with glaucoma or who underwent ophthalmic surgery were excluded.

Results. The patients received an average of 7.54 intravitreal injections. The mean baseline intraocular pressure was 15.3 mm Hg; 19.8 mm Hg at 24 hours; 17,4 mmHg at 1 week and 14.8 mmHg at 4 weeks after the administration of the anti-VEGF agent. 4 patients required long-term topical hypotensive treatment. Raised intraocular pressure was related to increased frequency of treatment. At 1 year follow up, an average difference of 2.1 mmHg compared to baseline was registered in the cases that have received more than 6 intravitreal injections. By comparison, in the cases treated with a reduced number of doses of intravitreal anti VEGF agent, the difference from baseline was 0,9 mmHg. There were no significant differences in mean IOP depending on the anti VEGF (bevacizumab or aflibercept) agent used.

Conclusions. Intravitreal treatment with anti VEGF agents produces a transient increase in intraocular pressure, predominantly immediately following administration, without causing long-term increased values.

Paracentesis following intravitreal drug injections in maintaining physiologic ocular perfusion pressure

A retrospective analysis was performed of patients who received a paracentesis immediately following an intravitreal injection of bevacizumab or triamcinolone acetonide. These patients were previously diagnosed as having glaucoma, ocular hypertension, or had responded previously with sustained elevated intraocular pressure. Of 1661 procedures were performed. Totally 219 (13%) of the injections were on phakic patients. A median (SD) of 210 µL (40 µL) of aqueous was removed during each paracentesis. There were no reported incidences of any complications. We propose performing a paracentesis immediately following intravitreal injections for patients at risk for ocular hypertension, glaucoma, and retinal vein or artery occlusion.

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.

Sustained intraocular pressure elevation in eyes treated with intravitreal injections of anti-vascular endothelial growth factor for diabetic macular edema in a real-life setting

PURPOSE

The aim of this study was to investigate the sustained intraocular pressure (IOP) elevation after repeated anti-VEGF intravitreal injections (IVI) in patients with diabetic macular edema (DME).

METHODS

A retrospective study included 140 eyes without prior glaucoma, treated with at least three anti-VEGF injections for DME between 2012 and 2016. IOP elevation was defined by an increase above baseline IOP by ≥6 mmHg. Baseline IOP was defined as the mean of IOP values before treatment initiation. Three groups were differentiated: group 1 without IOP elevation, groups 2 and 3 with IOP elevation and IOP <21 mmHg (group 2) and ≥21 mmHg (group 3). Rate and several risk factors of IOP elevation were assessed and compared between the three groups.

RESULTS

IOP elevation occurred in ten eyes (7.1%). IOP was <21 mmHg in six eyes and ≥21 mmHg in four eyes. Statistically significant associations were found between IOP elevation and the number of injections, and HbA1c level. Two patients required local hypotonic treatment.

CONCLUSIONS

In a real-life setting, we confirmed in eyes with center-involved DME without prior glaucoma or IOP elevation that repeated anti-VEGF IVI may increase the risk of sustained IOP elevation in about 7% of eyes.

Sustained Elevation of Intraocular Pressure Associated with Intravitreal Administration of Anti-vascular Endothelial Growth Factor: A Systematic Review and Meta-Analysis

This study aimed to assess whether repetitive intravitreal injections (IVI) of anti-vascular endothelial growth factor (anti-VEGF) cause sustained elevation of intraocular pressure (SE-IOP). We conducted a systematic review and meta-analysis based on five randomized controlled trials (RCTs) assessing 1428 subjects and 17 non-RCTs evaluating 8358 cases. In the RCTs, an increased risk of SE-IOP was found in the anti-VEGF group (summary risk ratio [RR] = 3.00, 95% confidence interval [CI]: 1.63–5.53) compared with the sham injection or laser group. The increased risk of SE-IOP was correlated with follow-up duration (RR = 2.14, 95% CI 0.69–6.57 at 6 months; RR = 3.15, 95% CI 0.99–10.09 at 12 months; RR = 3.48, 95% CI 1.38–8.78 at 23 months). The risk of SE-IOP after non-exclusion of pre-existing glaucoma patients (RR = 3.48, 95% CI 1.38–8.78) was higher than that obtained after excluding pre-existing glaucoma patients (RR = 2.6, 95% CI 1.16–5.81). In non-RCTs, the pooled prevalence of SE-IOP was 4.7% (95% CI 3.7–5.8) regardless of diagnosis criteria. In conclusion, repeated intravitreal injections of anti-VEGF agents cause a 2-fold elevation in SE-IOP risk.

The era of anti-vascular endothelial growth factor (VEGF) drugs in ophthalmology, VEGF and anti-VEGF therapy

Angiogenesis is a clue process for tissue development and function, both in normal and pathological conditions. This process is regulated by multiple molecular systems. One of the most potent is vascular endothelial growth factor (VEGF) and its receptor (VEGFR) system. Members of this family are involved in new vessel formation in embryogenesis and maturation, as well as in reparative or pathological reactions in later stages. They play a substantial role in regeneration, inflammation, wound healing, as well as in cancer pathology. Nowadays it is possible to modulate VEGF-VEGFR interactions in many pathological conditions using anti-VEGF therapy. This therapy has already achieved a grounded position in the management of rheumatological disorders, tumour progression, and metastasis. Such drugs as bevacizumab, ranibizumab, aflibercept, and pegaptanib have also proven to be very effective in the treatment of several ocular diseases, such as age-related macular degeneration (AMD), macular oedema, or proliferative retinopathies and iris neovascularisation. The indications for the application of this therapy in ophthalmology are becoming wider and wider. It may also be used for corneal pathologies and in anti-glaucoma procedures.