When is retrobulbar administration used?
This is the deepest of the periocular routes of administration; it provides the highest concentration of the drug at the optic nerve. Indications: neuritis and atrophy of the optic nerve, severe vascular disorders of the posterior segment of the eye, as well as anesthesia before ophthalmological operations. The procedure requires precise knowledge of the orbital anatomy and is performed only by an ophthalmologist; due to the depth of administration, it is performed less frequently than parabulbar injections, and for more stringent indications.
Why is the drug injected into the eye?
The eye is separated from the general bloodstream by a blood-ophthalmic barrier: the medicine taken in tablets reaches the retina in a negligible concentration. Therefore, local administration is widely used in ophthalmology - drops, injections under the conjunctiva, parabulbar, retrobulbar and directly into the vitreous body.
The deeper the drug is injected, the higher the concentration in the desired area, but the stricter the requirements for sterility and technique.
Types of drug administration
- subconjunctival - under the mucous membrane of the eye
- parabulbar - in the tissue around the eyeball
- retrobulbar - behind the eyeball, closer to the optic nerve
- intravitreal - directly into the vitreous body
What is important for the patient to know
Injections are performed after instillation of anesthetic drops, so pain is minimal. A slight hemorrhage under the conjunctiva after an injection is a common and safe occurrence; it resolves in 1–2 weeks. You should consult a doctor if pain increases, vision decreases, and redness increases a day after the procedure.