Photoactivated riboflavin treatment of infectious keratitis using collagen cross-linking technology.

PURPOSE: To evaluate riboflavin/ultraviolet-A (UVA) as an adjunct treatment for infectious keratitis. METHODS: This prospective, dual-center, interventional case series included cases of infectious keratitis that were treated by instilling riboflavin 0.1% solution for 30 minutes to saturate the cornea, followed by exposure to 365-nm UVA light (3 mW/cm(2)) for 15 to 45 minutes, with continued instillation of riboflavin. Eyes continued on standard antibiotic treatment. The primary outcome measures were the times to resolution of the infiltrate and the epithelial defect. RESULTS: Forty patients aged 14 to 86 years were enrolled. Seven (18%) eyes had a previous keratoplasty. Bacterial species were identified in 24 eyes, fungal in 7, protozoan in 2, viral in 1, and no organism in 6. The maximum infiltrate diameter ranged from 1 to 12 mm and the epithelial defect diameter was 0 to 8 mm before treatment. In 6 cases (2 bacterial, 3 fungal, and 1 without growth), the keratitis did not resolve successfully and the eye received a penetrating keratoplasty (PK). In 1 eye with prior PK, the infection resolved following treatment, but a regraft was required to address perforation of the PK incision. CONCLUSIONS: Riboflavin/UVA should be avoided in eyes with prior herpes simplex but otherwise posed no obvious safety risk in this series and appeared to be most effective when the infection depth was limited. The success rate was higher for bacterial infections than fungal infections. Randomized studies against antibiotics alone are needed to further evaluate efficacy.

Can intraocular lenses deliver antibiotics intracamerally?

PURPOSE: To determine the therapeutic concentrations of moxifloxacin achieved in an artificial anterior chamber by soaking the hydrophobic acrylic AcrySof™ SA60 (Alcon Inc.) intraocular lens (IOL) and the hydrophilic collamer Afinity™ CQ2015 (Staar Inc.) IOL in commercially available moxifloxacin 0.5% (Vigamox™; Alcon Inc.). METHODS: Forty IOLs (20 Acrysof SA60 and 20 Afinity CQ2015) were soaked in 1 mL of commercially available moxifloxacin 0.5%: 10 of each IOL for 1 min, and another 10 of each IOL for 10 min. The IOLs were placed on absorbent pads for 10 s on each side to dry excess liquid, and then placed in vials of 10 mL balanced salt solution (BSS™) for 30 min. Five milliliters of the balanced salt solution was removed and analyzed by high-pressure liquid chromatography to determine antibiotic levels. RESULTS: The moxifloxacin levels achieved after soaking the hydrophobic SA60 lens were 0.238 and 0.342 µg/mL for 1 and 10-min soaks, respectively. The moxifloxacin levels achieved after soaking the hydrophilic CQ2015 lens were 0.283 and 0.717 µg/mL for 1 and 10-min soaks, respectively. CONCLUSIONS: Both lenses were capable of delivering clinically significant antibiotic levels after a 1-min soak. Moxifloxacin concentrations reached at both 1 and 10-min soak times exceed the MIC(90) of the most common pathogens responsible for postoperative endophthalmitis. The antibiotic-soaked IOL has potential to become a clinically significant technique in the prevention of postoperative endophthalmitis.

In vitro antimicrobial efficacy of riboflavin and ultraviolet light on Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Pseudomonas aeruginosa.

PURPOSE: Ultraviolet (UV) light and riboflavin has been developed as a collagen cross-linking treatment for corneal ectasia. This treatment has also been used to treat infectious corneal ulcers with apparent favorable results. In this experiment, the antibacterial action of riboflavin alone, UV light alone, and the combination of riboflavin and UV light was tested on Staphylococcus aureus, methicillin-resistant S aureus (MRSA), and Pseudomonas aeruginosa. METHODS: Thirty agar plates with S aureus overlays were used. Ten plates were exposed to riboflavin (0.1% solution in dextran) alone, 10 plates were exposed to UV light (365 nm) alone, and 10 plates were exposed to a combination of riboflavin and UV light. Fifteen agar plates with MRSA and 15 plates with P aeruginosa were tested. Five plates of each group were exposed to riboflavin, 5 plates of each group were exposed to UV light alone, and 5 plates of each group were exposed to a combination of riboflavin and UV light. All plates were incubated for 24 hours and then analyzed. RESULTS: All plates exposed to riboflavin alone showed no bacterial death. All S aureus and MRSA plates exposed to UV light alone showed no bacterial growth. Three of five P aeruginosa plates exposed to UV light alone showed no bacterial death; two of five P aeruginosa plates exposed to UV light alone showed minimal inhibition. All plates exposed to the combination of riboflavin and UV light showed bacterial death. CONCLUSIONS: Riboflavin in combination with UV light is an effective modality to eradicate the bacteria S aureus, MRSA, and P aeruginosa.

Antimicrobial activity of acrylic intraocular lenses soaked in fourth generation fluoroquinolones.

PURPOSE: The aim of this study was to determine whether a commercially available brand of intraocular lenses (IOLs) soaked in moxifloxacin or gatifloxacin for 1 or 60 min have antimicrobial properties. METHODS: The IOLs (N = 8-10/group) were soaked in saline, physiologic-strength moxifloxacin (1.8 microg/mL), or gatifloxacin (0.48 microg/mL) for 60 min or commercial-strength moxifloxacin (5 mg/mL) or gatifloxacin (3 mg/mL) for 1 or 60 min. Presoaked IOLs and gatifloxacin antibiotic disks were plated on agar with quality-controlled ATCC 25923 Staphylococcus aureus overlay. Bacterial kill zones were measured after 24 h. RESULTS: IOLs soaked in physiologic-strength gatifloxacin or saline for 60 min produced no measurable bacterial kill zone, and the mean bacterial kill zone for IOLs soaked in physiologic-strength moxifloxacin was significantly greater (P = 0.011, 0 vs. 3.88 +/- 3.18 mm, respectively). Soaking the IOLs in commercial-strength moxifloxacin or gatifloxacin for 1 or 60 min produced significantly larger bacterial kill zones (P < 0.0001, mean: > or =33 mm for all groups). Soaking for 1 min produced a significantly larger mean bacterial kill zone by moxifloxacinthan gatifloxacin-treated IOLs (P = 0.002, 38.80 +/- 3.74 mm, 34.30 +/- 1.34 mm, respectively). The mean bacterial kill zone was significantly larger for IOLs soaked in commercial-strength moxifloxacin for 1 versus 60 min (P = 0.002, 38.80 +/- 3.74 mm, 33.56 +/- 1.42 mm, respectively). There was no significant difference in the mean bacterial kill zone between IOLs soaked for 1 or 60 min in commercial-strength gatifloxacin (34.30 +/- 1.34 mm, 33.67 +/- 0.50 mm, respectively).

Nepafenac-associated corneal melt.

We describe a patient with systemic graft-versus-host disease who developed a nonhealing epithelial defect after cataract surgery that healed on cessation of a topical nonsteroidal antiinflammatory drug (NSAID) (ketorolac). The patient developed a central corneal perforation in the fellow eye while on a new NSAID formulation (nepafenac) after routine cataract surgery. Our case suggests that new topical NSAIDs may be similar to older NSAID formulations in promoting corneal melting in patients predisposed to poor epithelialization and corneal wound healing.

Tegaderm transparent dressing (3M) for the treatment of chronic exposure keratopathy.

We report an effective alternative treatment of profound chronic exposure keratopathy in a proptotic eye due to intraorbital extension of basal cell carcinoma. The corneal surface gradually reepithelialized in a 6-week period after the first application of Tegaderm transparent dressing (3M, St. Paul, MN, U.S.A.) with instillation of antibiotic ointment on the ocular surface. The patient has been comfortable with an intact epithelial surface, a vascularized cornea, and nonirritated surrounding skin after changing the Tegaderm dressing daily for 15 months. There was no evidence of recurrent corneal ulceration or infiltrations. We conclude that Tegaderm represents a useful treatment of exposure keratopathy due to chronic proptosis.

Regression of presumed primary conjunctival and corneal intraepithelial neoplasia with topical interferon alpha-2b.

PURPOSE: To evaluate topical interferon alpha-2b (IFNalpha2b) as a lone therapy in the treatment of primary conjunctival and corneal intraepithelial neoplasia (CIN). METHODS: Noncomparative, prospective, interventional case series. Seven patients from three institutions, treated between February and October 1999, with presumed primary CIN lesions (clinically diagnosed by corneal specialists) were given topical IFNalpha2b drops (1 million units/mL) four to six times daily. Follow-up was performed biweekly until there was complete clinical resolution of the presumed CIN lesions. Patients were to continue topical IFNalpha2b drops for 1 month after clinical resolution. Patient charts and clinical photographs were reviewed, and data were analyzed. RESULTS: All seven eyes had complete resolution of the presumed CIN lesions after an average of 77.0 +/- 59.2 days (range, 28-188 days). Average posttreatment follow up was 12.4 +/- 2.5 months (range, 9-16 months). No patients were lost to follow-up. No recurrences have yet been seen. Side effects of treatment were limited to mild conjunctival hyperemia and follicular conjunctivitis in four (57.1%) eyes. In all cases, there was total resolution of conjunctival hyperemia and follicular changes within 1 month after cessation of the medication, without additional treatment. CONCLUSIONS: Topical IFNalpha2b alone may be an effective treatment of primary CIN. It appears to be a safe alternative to radiation, intralesional IFNalpha2b injection, and surgical excision with cryotherapy. Larger population studies with longer follow-up are recommended to better assess the risk of recurrence and other possible adverse effects.