Restoring Sight with Science: The Promising Future of Corneal Infection Treatment

(Posted on Saturday, February 3, 2024)

This story is part of a series on the current progression in Regenerative Medicine. This piece is part of a series dedicated to the eye and improvements in restoring vision. 

In 1999, I defined regenerative medicine as the collection of interventions that restore tissues and organs damaged by disease, injured by trauma, or worn by time to normal function. I include a full spectrum of chemical, gene, and protein-based medicines, cell-based therapies, and biomechanical interventions that achieve that goal.

Contact lenses have become popular for people who want an alternative to glasses, as they provide greater comfort and convenience. However, contact lenses increase the risk of developing eye infections, including corneal diseases. 

Corneal infections caused by contact lenses can lead to severe complications, including permanent vision loss. Fortunately, the Orphan Drug for Acanthamoeba Keratitis (ODAK) Trial has shown that a new treatment protocol could be as effective as current treatments in treating corneal infections.

Explanation of Corneal Infection from Contacts

Corneal infections, like acanthamoeba keratitis, are a type of eye infection that can occur when microorganisms like bacteria, fungi, or amoeba penetrate the cornea. The cornea is the transparent outer layer of the eye that covers the iris and pupil and is critical in focusing light on the retina. 

Wearing contact lenses increases the risk of corneal infections due to several factors. One of the primary factors is decreased oxygen permeability, which can cause corneal swelling and the accumulation of debris and microorganisms on the contact lens. Other factors include poor hygiene, improper cleaning of contact lenses, and wearing contact lenses for an extended period.

Symptoms of corneal infections can vary depending on the type of infection. Still, they typically include eye pain, redness, sensitivity to light, and blurred vision. In severe cases, corneal infections can lead to permanent vision loss or even require corneal transplant surgery. 

More Details on Acanthamoeba Keratitis

Acanthamoeba keratitis is an eye infection that commonly affects people who wear contact lenses. The risk is exceptionally high for those who fail to sanitize and store their lenses properly. Other factors that can increase the risk of infection include making homemade saline solutions or wearing contact lenses while swimming. Acanthamoeba organisms thrive in warm water, so using water sources properly is essential to reduce the risk of infection. People who work with vegetable matter or soil may also be at higher risk of acanthamoeba keratitis.

The symptoms of acanthamoeba keratitis may initially seem similar to other eye conditions like bacterial or viral keratitis, making its accurate diagnosis challenging. Some of the symptoms of this condition include eye pain, light sensitivity, eye redness, and vision loss. Acanthamoeba keratitis can lead to cornea scarring, resulting in permanent visual impairment. In severe cases, surgical intervention may be required due to corneal perforation.

Effectiveness of Treatment & Current Treatments

The treatment options available depend on the cause of the infection. The treatment usually involves topical or oral antibiotics, antifungal agents, or antiviral medication. In severe cases, surgical intervention may be necessary. The type of surgery required depends on the severity of the infection and the extent of the damage to the cornea. Some common surgical interventions for corneal infections include corneal transplant, penetrating keratoplasty, and lamellar keratoplasty.

The treatment of Acanthamoeba keratitis is most effective when medical and surgical methods are used together. Diagnosing the infection early and accurately is critical to get the best response to therapy. Medications like biguanides, antiseptics, and antifungal agents may be necessary to treat the infection. 

In severe cases, combination therapy may extend over several months. The use of steroids in treating Acanthamoeba keratitis is controversial, as it may delay healing or worsen the condition. For larger corneal ulcers or perforations, surgical interventions may be necessary. 

Summary of the ODAK Trial

The ODAK trial is an extensive study investigating the efficacy of a new treatment protocol for acanthamoeba keratitis, a rare but severe corneal infection commonly associated with contact lens wear. Traditionally, one of the treatments for this condition involves the use of dual therapy, a combination of PHMB 0.02% and propamidine. However, the new treatment protocol utilizes a single agent, PHMB 0.08%, which was the trial’s focus. 

The trial was conducted over several months, and many participants were involved. The trial results showed that the new treatment protocol was highly effective, with a medical cure rate of over 86%. This is comparable to the current dual therapy, which has been the standard of care for many years. Notably, the new treatment protocol was found to be safe and well-tolerated by patients, indicating that it could be a viable alternative to traditional dual therapy. 

The trial also revealed that the new treatment protocol was more accessible to administer than the dual therapy. Patients only needed to use a single agent, which simplified the treatment process and reduced the likelihood of errors in medication administration. Additionally, the new protocol was less expensive than the traditional dual therapy, which could make it more accessible to a broader range of patients.

Based on the trial’s findings, it is suggested that the new treatment protocol can potentially become the new standard of care for acanthamoeba keratitis. Patients with this condition could benefit from a more effective, streamlined, affordable treatment option. 

The trial results provide hope for improved outcomes for patients diagnosed with this rare but severe corneal infection. Ultimately, further research is still necessary to enhance the management and treatment of corneal infections resulting from wearing contact lenses.

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