This month, a landmark PACK-CXL trial was published that shows that PACK-CXL is an effective corneal infection therapy.
The authors wanted to know if standalone photoactivated chromophore corneal cross-linking (PACK-CXL) may be an effective first-line treatment in early to moderate infectious keratitis, compared with standard antimicrobial treatment. To do this, they performed a large, international, multi-center, phase III clinical trial that involved patients with infectious keratitis that was thought to be caused by bacteria, fungi or a mixture of the two. What they were looking for was “treatment success” – the complete resolution of any sign of infection- and time to re-epithelialzation (where the protective cells at the top of the cornea have re-grown). Patients with corneal ulcers were either treated with PACK-CXL alone, or standard antimicrobial therapy.
Both treatments were similarly and highly successful: 88.9% of PACK-CXL-treated patients, and 90.5% of antimicrobial therapy-treated patients experienced treatment success, and there was no difference in time to re-epithelialisation between treatment groups.
The importance of these results cannot be understated: there is a great unmet need for effective therapies against infectious keratitis (corneal infection), which is a major cause of global blindness. This is set against a background of increasing antimicrobial drug resistance. For example, the last new antibiotic was discovered in 1987, and bacteria have continued to develop resistance to the drugs we currently have available to treat them.
But there is another important benefit that PACK-CXL has over antimicrobial treatment: doctor time. PACK-CXL can successfully treat most cases with a single treatment. Antimicrobial therapy requires intensive, hourly, round-the-clock treatment with frequent, regular follow-ups from a doctor. In developing countries, this level of care is often out of the reach of most of the population for a number of reasons:
- The cost is prohibitive. Even if a patient could afford the first treatment, they might not afford the subsequent appointments. This is clearly a bad situation, as the patient requires intensive and frequent therapy for effective treatment to occur.
- Access to doctors is limited. Most ophthalmologists in developing countries are located in large population centers, where the hospitals are. Most of the population live in distant, rural areas.
- Loss of vision equals loss of livelihood. Most people in developing countries work in agriculture, and vision loss can severely inhibit people from continuing to do that job. Worse, one of the most common causes of infectious keratitis is fungi introduced to the cornea through plant material scratching the eye.
The development of battery-powered, portable cross-linking devices that can be used anywhere means that PACK-CXL can be brought to even the most rural of locations, which can in many cases, in a single treatment, effectively treat the infection, saving these people’s vision. Which all underlines the importance of the results from this landmark PACK-CXL trial.
Click on the image below to view the PDF.
Hafezi F, Hosny M, Shetty R, et al. PACK-CXL vs. antimicrobial therapy for bacterial, fungal, and mixed infectious keratitis: a prospective randomized phase 3 trial. Eye Vis (Lond). 2022;9(1):2.