Title: Treatment of Pseudomonas Keratitis by Continuous Infusion of Topical Antibiotics with the Morgan Lens
Authors: Mingwu Wang, MD, PhD, Whitney A. Smith, MD, Joshua K. Duncan, DO, and Joseph M. Miller, MD, MPH.
Cornea, 2016 (Summary below prepared from the abstract of Dr. Wang’s presentation at the Association for Research in Vision and Ophthalmology conference, Seattle, WA, May, 2016, and the article published in 2016 in the journal Cornea)
Purpose: Despite following standard treatment, Pseudomonas keratitis can continue to progress and result in loss of vision or eye. Therefore, rapid containment of aggressive and refractory infection is imperative. Our cases demonstrate that Morgan Lens can be an effective topical antibiotic delivery vehicle in cases of advanced keratitis.
Methods: Two patients (three eyes) were included in this report. Patient 1 was an 11-year-old healthy female diagnosed with contact lens-related Pseudomonas keratitis in the right eye. Over a 2-week treatment including topical 15mg/ml tobramycin q1h and ciprofloxacin QID, the keratitis worsened and corneal perforation appeared imminent. Patient 2 was an 11-month old female with Apert syndrome who was admitted for a complicated pneumonia and on a respirator. Bilateral lagophthalmos led to exposure keratitis and subsequent Pseudomonas keratitis. Aggressive fortified antibiotics q1h over two days did not contain the destructive infection. In all affected eyes, a Morgan Lens was inserted under both eyelids, connected to IV tubing and the tubing taped to the forehead. In the intubated 11-month old patient with bilateral infections, the Morgan Lens was further secured in place by a temporary tarsorraphy. Ceftazidime (50mg/ml) was the key antibiotic infused at 20ml/hour through the IV tubing and Morgan Lens over the ocular surface.
Results: Three days after infusion through the Morgan Lens, corneal cultures became negative in all eyes. The infusion was continued for at least a week to ensure definitive eradication of the infection before switching to standard topical antibiotic therapy. Topical steroid and amniotic membrane were used as adjuncts when necessary in the acute recovery phase to control inflammation. A combined cataract and corneal transplant 9 months later in patient 1 led to a spectacle-corrected vision of 20/60. In patient 2, the corneas remain epithelialized with stable scars and await transplant surgeries after the lagophthalmos are corrected.
Conclusions: This application of the Morgan Lens is non-invasive and requires minimal training and monitoring by caregivers. It can deliver high concentration antibiotics to the entire ocular surface and possibly to the intraocular tissues as well. Continuous lavage is performed in standard concentrations at a rate sufficient to keep pathogens from accumulating. IV connectors allow for an easy switch between medications or simultaneous administration of multiple medications, and titration of dosing. Additionally, monitoring of therapeutic effects is not hindered. Our cases suggest that Morgan Lens can be very effective in treating severe and aggressive infectious keratitis or sclerokeratitis. It is cost-effective as the low demand for nursing care essentially eliminates the need for intensive care unit admission.
From the discussion: Continuous lavage with antibiotics using the Morgan Lens has been shown to be more effective than topical therapy in animal models and was able to achieve higher concentrations in the aqueous humor when compared with drops administered every 15 to 30 minutes. Applying drops at this frequency, or even hourly, is difficult for patients, and if admitted, often requires ICU-level nursing care with drastically increased cost. Human studies have shown that the use of the Morgan Lens is safe for up to 15 days. Because of its ease of use, efficacy, ready availability, and increased patient compliance, we strongly believe that continuous antibiotic infusion through the Morgan Lens should be considered a viable alternative therapy for refractory or fulminant corneal infections.