Article

Advances in drug delivery systems

New methods present opportunities for increased patient compliance and fewer call backs.

Your cataract surgery patient just had a successful procedure. But, as the patient and his wife leave your office satisfied, you suspect you might be hearing from them again — and soon.

Although you did your best to describe the post-surgery eyedrop regimen, you perceived that perhaps the patient and his wife understood only every other word. So, you brace yourself for the multiple phone calls that might be needed to help this couple through the post-surgery period.

In all fairness, cataract patients are asked to manage a fairly complex eyedrop regimen. You may ask elderly patients with several coexisting diseases to manage multiple drops up to four times daily, with a taper over a four-week to six-week course. Between steroids, antibiotics, and NSAIDs, your cataract patients may have to instill more than 100 drops over four weeks.

What’s more, your patient stands a good chance of administering those drops improperly. About 93% of cataract patients without previous eyedrop experience improperly administered their drops following surgery, a 2014 study published in the Journal of Cataract and Refractive Surgery found.

Fortunately, alternative ways to handle drug administration are dawning. These methods remove the onerous task of drop administration for patients, allowing the surgeon to deliver the appropriate dose of medication at the time of surgery. Also, these methods are being developed to help patients who suffer from other conditions, such as uveitis.

Read on to learn about the latest advances in these drug delivery systems, which can help minimize office callbacks and improve patient care.

Intracameral injection

This technique involves injecting into the anterior chamber. Benefits include a familiar anatomic landscape (minimal learning curve for the surgeon), no need for additional instruments, and the speed of the procedure. Injecting the medication into the anterior chamber is very quick; it is not a lengthy, time-consuming step.

For postoperative inflammation after cataract surgery, the only FDA-approved product is dexamethasone intraocular suspension 9% (Dexycu, EyePoint Pharmaceuticals). Dexycu delivers a relatively high initial dose that tapers over time, resulting in a sustained clinical effect for up to 30 days.

Dexycu is injected under the iris at the end of cataract surgery. The drug is administered as a single 5-µL suspension, which forms a roughly 2-mm sphere after it’s placed in the eye. Dexycu uses a sustained-release technology (Verisone) that is bioerodible (it erodes over time without leaving any residue). As it breaks down, the dexamethasone diffuses into the eye.

Dexycu has a permanent J code and has been approved for transitional pass-through status for payment for three years.

Doctors can also inject non-FDA-approved antibiotic solutions, such as moxifloxacin or a combination of a steroid/antibiotic into the anterior chamber. The intracameral technique can be quite effective. The European Society of Cataract and Refractive Surgeons Endophthalmitis Study found that intracameral cefuroxime 1mg/0.1ml resulted in a fivefold decrease in the rate of postoperative endophthalmitis after cataract surgery. However, there is no FDA-approved antibiotic for intracameral use in the United States.

Yutiq (fluocinolone acetonide) is another implant that uses EyePoint’s sustained-release technology. It is intended for the treatment of chronic non-infectious uveitis affecting the posterior segment of the eye. Like Dexycu, Yutiq provides sustained release of the active drug over time.

Transzonular injection

With this technique, mainly used for cataract surgery, a drug is injected through the zonules into the anterior vitreous. Not many ophthalmologists use this drug delivery approach as it may be a new technique for them to learn and it is a slightly blind maneuver. Used in cataract surgery, the medication is either a combination of an antibiotic and steroid (Tri-Moxi, or triamcinolone and moxifloxacin, compounded by ImprimisRx) or a steroid alone. No products currently have FDA approval.

Pars plana injection

With this method, the drug is injected into the anterior vitreous through the pars plana. Pars plana injections also have a steep learning curve for the ophthalmologist. The patient may experience slight discomfort, and there is the possibility of a small subconjunctival hemorrhage. This technique creates a new injection site, which may cause bacteria to potentially gain access to the inside of the eye, leading, rarely, to infection. Like the transzonular method, the drug can be a combination of an antibiotic and steroid or a steroid alone.

Alternative drug delivery system benefits

  • Bypass the cornea
  • Less impact on tear film and ocular surface1
  • Visual acuity better on the first postoperative day (assuming a surgical procedure)1
  • Eliminate compliance challenges
  • Lift drop burden from patients and caregivers
  • Decrease callbacks to the practice (avoid tying up technician time)
  • Less time spent explaining a potentially confusing postoperative drop regimen to the patient and caregiver

Reference

  1. Tyson SL, Bailey R, Roman JS, et al. Clinical outcomes after injection of a compounded pharmaceutical for prophylaxis after cataract surgery. Current Opinion in Ophthalmology. 2017;28(1):73-80.

Sub-Tenon’s injection

With this method, a steroid is injected under the Tenon’s capsule for slow release. There is a small learning curve. This technique may cause mild discomfort for the patient and can, from time to time, lead to a subconjunctival hemorrhage. These are used off label.

Punctal plug

Also called lacrimal plugs, these devices allow physicians to administer drugs before, during, or after surgery.

In cataract surgery, the FDA recently approved dexamethasone ophthalmic insert 0.4mg (Dextenza, Ocular Therapeutix) for the treatment of pain following ophthalmic surgery (see Figure 1, page 28). The intracanalicular plug is easy to insert into the inferior punctum with a minimal learning curve for the surgeon. Clinicians can flush out the plug if they note an intraocular pressure spike. One drawback is that punctal anatomy may limit the suitability of plug insertion for some patients.

Figure 1. Dextenza (Ocular Therapeutix) activates with moisture and swells to fit in the canaliculus (A), releases dexamethasone for up to 30 days (B), and reabsorbs slowly through the course of treatment and clears via the nasolacrimal duct (C).

Ocular Therapeutix plans to have samples available for product training in May and hopes to receive a C code (pass-through) for reimbursement, which would take effect on July 1.

Enhanced experience

While much of the current activity in advanced drug delivery systems focuses on cataract surgery, clinicians are sure to see pharmaceutical companies address other conditions. For instance, injections to address glaucoma are on the horizon.

These post-procedure delivery methods can enhance the patient experience. They decrease the drop burden, help reduce or eliminate issues with patient compliance, which can improve patient outcomes. OP