Subconjunctival injections–under development by several companies–represent an approach that can be delivered at the slit-lamp. However, it is still an invasive procedure and has been associated with inconsistent delivery and batch-to-batch reproducibility issues.
“Historically, frequent injections are needed,” Dr. Kahook pointed out. “That raises questions about the development of scarring that might preclude future glaucoma surgery.”
Data for intraocular injections of glaucoma medication depots show they have IOP-lowering efficacy approaching that of topical prostaglandin analogue. The approach, however, is invasive, and it is unclear whether it is a procedure that can be done at the slit-lamp.
“Administration of these injections is something that must be done with the patient lying on a bed in a procedure room, which is not available in every office,” Dr. Kahook said. “Data are needed to establish long-term drug delivery and safety.”