Observation of Silicone Oil Within the Vitreous and Sclera Following Intravitreal Administration of Biotherapeutics Using Insulin Syringes in Cynomolgus Monkeys

[Translated article] Syringes for intraocular administration: A systematic review

OBJECTIVE

The off-label use in clinical practice of non-approved syringes for intravitreal drug administration has resulted in the detection of silicone oil drops in the vitreous of some patients. This situation derives from the lack of approved syringes for intraocular use in the Spanish market. The aim of this work is to review the use of syringes for intraocular administration, as well as to search for alternatives that meet the legal requirements for these unmet needs.

METHOD

A systematic review was performed following the PRISMA 2020 guidelines by searching PubMed with the descriptors: (silicone) AND (syringes) AND ((intraocular) OR (intravitreal)) and filtering all existing publications from January 2006 to December 2023, including all those articles dealing with silicone oil release in intravitreal injections and analysing the possible consequences.

RESULTS

Sixty-eight results were found, 23 of which were excluded because they did not deal with the subject under study, leaving a total of 45 articles for the systematic review. These were classified according to the conclusions obtained in 4 groups: the adverse reactions produced by silicone; the administration technique; the physicochemical aspects of silicone release; and the characteristics of the medical device. After reviewing the current manufacturers and technical data sheets of commercialised syringes, the existing syringes for this use have been collected, finding 2 that will probably be commercialised in Spain at the beginning of 2024: Zero Residual™ 0.2 ml SiO-free and VitreJect® Ophthalmic.

CONCLUSIONS

From the results obtained, it can be interpreted that the use of syringes and needles with silicone for intravitreal use is a concern for health professionals due to the implications and consequences that may arise in patients, the most important being adverse reactions, so it is necessary to have silicone-free syringes on the market that are specific for intraocular use. Safety and legality in the use of intraocular syringes and needles is essential to guarantee ocular integrity and patient health.

Syringes for intraocular administration: Systematic review

OBJECTIVE

The off-label use in clinical practice of non-approved syringes for intravitreal drug administration has resulted in the detection of silicone oil drops in the vitreous of some patients. This situation derives from the lack of approved syringes for intraocular use in the Spanish market. The aim of this work is to review the use of syringes for intraocular administration, as well as to search for alternatives that meet the legal requirements for these unmet needs.

METHOD

A systematic review was performed following the PRISMA 2020 Guidelines by searching PubMed with the descriptors: "silicone" AND "syringes" AND ("intraocular" OR "intravitreal") and filtering all existing publications from January 2006 to December 2023, including all those articles dealing with silicone oil release in intravitreal injections and analysing the possible consequences.

RESULTS

Sixty-eight results were found, 23 of which were excluded because they did not deal with the subject under study, leaving a total of 45 articles for the systematic review. These were classified according to the conclusions obtained in 4 groups: the adverse reactions produced by silicone, the administration technique, the physicochemical aspects of silicone release, and the characteristics of the medical device. After reviewing the current manufacturers and technical data sheets of commercialized syringes, the existing syringes for this use have been collected, finding two that will probably be commercialized in Spain at the beginning of 2024: Zero Residual™ 0.2 ml SiO-free and VitreJect® Ophthalmic.

CONCLUSIONS

From the results obtained, it can be interpreted that the use of syringes and needles with silicone for intravitreal use is a concern for health professionals due to the implications and consequences that may arise in patients, the most important being adverse reactions, so it is necessary to have silicone-free syringes on the market that are specific for intraocular use. Safety and legality in the use of intraocular syringes and needles is essential to guarantee ocular integrity and patient health.

Intraocular Pressure Elevation Following Intravitreal Anti-VEGF Injections: Short- and Long-term Considerations

Published studies agree that transient intraocular pressure (IOP) spikes are common after intravitreal injections of anti-vascular endothelial growth factor agents. Currently, there is no standard of care guiding if and when to prevent these IOP spikes. Furthermore, there are challenges in determining the impact of postinjection IOP elevation on the health of the retinal ganglion cells, particularly given the often-existing comorbidities of retinal and glaucoma pathology. This review highlights the current literature regarding both acute and chronic postinjection IOP elevations and discusses management of postinjection IOP elevation, especially in patients at high risk for glaucomatous damage.

Spontaneous Background and Procedure-Related Microscopic Findings and Common Artifacts in Ocular Tissues of Laboratory Animals in Ocular Studies

Identification of test article-related microscopic findings in ocular toxicology studies requires a working knowledge of the artifacts and procedure-related or background findings commonly encountered in such studies. The objective of this article is to provide a mini-atlas of the artifacts and procedure-related or spontaneous background findings commonly observed in ocular tissues from animals in toxicology studies of ocular drug candidates. Artifacts in the eye are often related to collection or fixation procedures and include swelling and vacuolation of lens fibers, separation of the neuroretina from the retinal pigment epithelium (RPE), and vacuolation of the optic nerve. Common in-life procedure-related findings include intravitreal injection needle tracks in the sclera and ciliary body pars plana and foci of RPE hypertrophy and/or hyperpigmentation at subretinal injection sites. Common background findings include corneal mineralization, uveal mononuclear cell infiltrates, and peripheral displacement of photoreceptor nuclei in the retina. A few uncommon spontaneous background findings that may be confused with test article-related findings, such as bilateral optic atrophy in macaques, are also included.