Reducing intraocular-pressure spike after intravitreal-bevacizumab injection with ocular decompression using a sterile cotton swab soaked in proparacaine 0.5%: A quasi-experimental study

Transient Vision Loss Associated with Prefilled Aflibercept Syringes

Purpose

To describe cases of significant vision loss after intravitreal aflibercept administration using prefilled syringes (PFS) and to study the relationships among syringe design, injection speed, and injection force.

Design

Retrospective case series and experimental study.

Participants

Twelve patients who received intravitreal aflibercept via PFS.

Methods

All retina specialists (n = 13) at Oregon Health & Science University and the Veterans Affairs Portland Medical Center were queried in December 2020 to report episodes of significant vision loss after aflibercept PFS use. Chart review was completed for all affected patients. Using a commercially available force measuring system, injection force was measured for aflibercept PFS, ranibizumab PFS, and a tuberculin syringe at various injection speeds.

Main Outcome Measures

Number of significant vision loss episodes after aflibercept PFS use and average injection force (Newtons) at various injection speeds across different syringes.

Results

Ten specialists (76.9%) reported a perceived increase in vision loss after injection with aflibercept PFS. Sixteen events of light perception or worse vision were reported immediate after aflibercept PFS use. Chart review was available for 12 of these events. The indication for aflibercept was exudative age-related macular degeneration (n = 8), diabetic macular edema (n = 3), and central serous chorioretinopathy (n = 1). The median age of affected patients was 71 years (range, 49–94 years). Two patients were being treated for glaucoma (n = 1) or ocular hypertension (n = 1); 1 patient was a glaucoma suspect. Anterior chamber paracentesis was performed in 4 patients to normalize intraocular pressure (IOP) promptly. Laboratory experiments demonstrated that higher injection speeds were associated with higher injection forces for all syringe types. Injection forces were consistently greater with aflibercept PFS than with the ranibizumab PFS or tuberculin syringe (P < 0.0001).

Conclusions

Retina specialists at our institutions have noted numerous cases of severe transient vision loss with aflibercept PFS use. The average injection force may be greater with the aflibercept PFS when compared with other intravitreal anti–vascular endothelial growth factor (VEGF) options. Additional clinical studies are needed to understand better how syringe design and fluid dynamics may contribute to vision loss after injection.

Reduction of Intraocular Pressure Spikes Due to Intravitreal Bevacizumab Injections by Scleral Indentation with Cotton Swab or Digital Ocular Massage: Innovative Techniques Compared

Purpose

This study aims to evaluate the effectiveness of different decompressive injection techniques in reducing intraocular pressure (IOP) spikes, if compared to the injection without pressure applied on the eye, following the intravitreal injection of bevacizumab.

Patients and Methods

Two hundred patients with indication to intravitreal therapy were randomized into five arms: 40 received intravitreal injection without ocular decompression (arm A), 40 with pre-injection scleral indentation with cotton swab (arm B), 40 with pre-injection digital ocular massage (arm C), 40 with post-injection scleral indentation with cotton swab (arm D) and 40 with post-injection digital ocular massage (arm E). All patients underwent measurement of the IOP with Goldamm applanation tonometer 10 minutes before and 10 minutes after the injection. The primary endpoint of the study was variation of the post- injection IOP with the different techniques.

Results

An increase in post-injection IOP was observed in all the arms, if compared to pre-injection values. The greatest increase was observed in arm A with a mean IOP rise of 17.60 mmHg. All other techniques showed lower mean IOP increases: arm B 10.76 mmHg, arm C 9.35 mmHg, arm D 8.8 mmHg, arm E 3.4 mmHg. The post-injection IOP differences of innovative techniques compared to the technique without ocular decompression were all statistically significant (p-value <0.01). If compared to arm A (35%), a reduction in IOP spike ≥40 mmHg frequency was also observed. The status of phakia/pseudophakia, a previous diagnosis of glaucoma and the underlying pathology for which indication was given to inject bevacizumab did not significantly alter the post-injection IOP in any of the protocols.

Conclusion

The introduction of new injection protocols, such as injections performed before or after decompressive treatments, could be a safe and effective approach to control post-injection IOP increase.

High Density Display of an Anti-Angiogenic Peptide on Micelle Surfaces Enhances Their Inhibition of αvβ3 Integrin-Mediated Neovascularization In Vitro

Diabetic retinopathy (DR), Retinopathy of Pre-maturity (ROP), and Age-related Macular Degeneration (AMD) are multifactorial manifestations associated with abnormal growth of blood vessels in the retina. These three diseases account for 5% of the total blindness and vision impairment in the US alone. The current treatment options involve heavily invasive techniques such as frequent intravitreal administration of anti-VEGF (vascular endothelial growth factor) antibodies, which pose serious risks of endophthalmitis, retinal detachment and a multitude of adverse effects stemming from the diverse physiological processes that involve VEGF. To overcome these limitations, this current study utilizes a micellar delivery vehicle (MC) decorated with an anti-angiogenic peptide (aANGP) that inhibits αvβ3 mediated neovascularization using primary endothelial cells (HUVEC). Stable incorporation of the peptide into the micelles (aANGP-MCs) for high valency surface display was achieved with a lipidated peptide construct. After 24 h of treatment, aANGP-MCs showed significantly higher inhibition of proliferation and migration compared to free from aANGP peptide. A tube formation assay clearly demonstrated a dose-dependent angiogenic inhibitory effect of aANGP-MCs with a maximum inhibition at 4 μg/mL, a 1000-fold lower concentration than that required for free from aANGP to display a biological effect. These results demonstrate valency-dependent enhancement in the therapeutic efficacy of a bioactive peptide following conjugation to nanoparticle surfaces and present a possible treatment alternative to anti-VEGF antibody therapy with decreased side effects and more versatile options for controlled delivery.