Corneal deposits after the topical use of ofloxacin in two children with vernal keratoconjunctivitis

Topical cenegermin associated ocular surface and contact lens drug precipitate deposit formation

Purpose

To report for the first time drug precipitate deposit formation on both the ocular surface and bandage contact lens (BCL) of a patient treated with topical cenegermin.

Observations

A patient suffering from stage III neurotrophic keratitis developed extensive ocular surface and BCL deposits over the eight week course of her topical cenegermin therapy. The ocular surface deposits were weakly adherent, detaching and clearing from the cornea within minutes of BCL removal. They reappeared rapidly and repeatedly however after each of five BCL exchanges. Symptom wise, the patient was unaware of their presence. Of historical note, this patient: (1) developed BCL ciprofloxacin deposits while undergoing a traditional neurotrophic keratitis treatment regimen, (2) did not develop corneal drug precipitate deposits within the placebo arm of the cenegermin clinical trial (vehicle only without cenegermin or BCL), and (3) did not develop corneal deposits with a latter BCL-free cenegermin treatment course.

Conclusions and Importance

Topical cenegermin can produce extensive drug precipitate deposits on both the ocular surface and contact lens when used in conjunction with a bandage contact lens. Such deposits: (1) may represent an esthetic issue only as at least in our patient they were not symptom provoking, questionably interfered with the clinical course of the cenegermin therapy and did not require drug cessation, (2) may implicate both contact lenses and high frequency drug application as previously unidentified but formal risk factors for drug precipitate deposit formation, and (3) may act as a time-release medication reservoir enhancing drug delivery and long-term treatment efficacy.

Corneal deposition of fluoroquinolones after penetrating keratoplasty: case series

Purpose: To report three cases of fluroquinolone deposition in the cornea after topical administration post-penetrating keratoplasty. Case reports: Herein we report three patients ranging in age from 42-65 years who underwent keratoplasty with cataract extraction, with intraocular lens implantation in the first two cases and left aphakic due to a posterior capsular tear in the third case. The first two patients received ciprofloxacin-dexamethasone combination drops, and developed drug deposition, which was observed at the first follow-up after 7 and 10 days respectively. The third patient received prednisolone acetate and ofloxacin eyedrops postoperatively, and developed drug deposits in the cornea after 20 days. In all of the three patients, the fluroquinolone group of drugs was discontinued and the cornea cleared gradually over the next 3-4 weeks. Although the cornea cleared, the first two grafts failed due to recurrent viral infection in one case, and graft rejection in the other case. Conclusion: Deposition of many different fluroquinolones in the cornea has been reported after a variety of surgeries, including penetrating keratoplasty. Drug deposition post-penetrating keratoplasty may seem innocuous due to self-resolution on cessation of the drugs, but it may have deleterious effects on graft survival. Hence, fluroquinolones, especially ciprofloxacin, should be cautiously used in patients undergoing penetrating keratoplasty if frequent dosing is prescribed or if used concurrently with other topical medications containing preservatives.

Sparfloxacin-associated corneal epithelial toxicity

Sparfloxacin is a broad-spectrum fluoroquinolone antibiotic commonly used for various bacterial corneal infections. Topical use of fluoroquinolones is considered to be safe leading to their widespread use. Common indications include blepharitis, conjunctivitis and corneal ulcers. However, unsupervised prolonged use is associated with deposition of crystalline material in the epithelial and anterior stromal layers of the cornea. These may be associated with significant visual symptoms including diminution of vision and glare/photophobia. We present a case of a 40-year-old man who was treated with topical 0.3% sparfloxacin unsupervised for a long time. The patient developed significant visual impairment due to diffuse epitheliopathy. Cessation of the drug was slowly followed by reversal of manifestations and normalisation of corneal morphology.

New insight into non-healing corneal ulcers: iatrogenic crystals

AIMS

To characterise and correlate crystalline precipitations implicated in non-healing corneal ulceration in two patients with a previous history of acanthamoeba keratitis.

MATERIALS AND METHODS

Persistence of acanthamoeba and secondary bacterial infection was excluded with negative corneal scrapes. Confocal microscopy identified crystal-like deposits within the corneal stroma. To investigate possible precipitating combinations, all concurrent treatments at the time of presentation were mixed in wells, with observation of precipitate formation. Precipitates were observed with phase-contrast microscopy, and subsequently characterised via crystallography techniques and electrospray ionisation mass spectrometry.

RESULTS

Combinations of dexamethasone 0.1% minims and chlorhexidine gluconate 0.2% formed an amorphous material characterised by electrospray ionisation mass spectrometry as an insoluble chlorhexidine salt. Combinations of chloramphenicol drops and timolol 0.5% formed a crystal identified via X-ray crystallography as santite (K(B₅O₆(OH)₄).(H₂O)₂). This is a borate mineral identified in nature, arising from thermal springs, but never reported in biological tissues. Clinical improvement was observed following the cessation of the implicated precipitating combinations.

CONCLUSION

Our observations suggest iatrogenic precipitate formation, with a potential deleterious effect upon healing. The substrates for these precipitates include several frequently prescribed topical ophthalmic treatments. These findings shed new light on the aetiopathogenesis of non-healing corneal ulceration, and have broad implications on topical prescribing for this challenging condition.

Preparation and evaluation of thermosensitive liposomal hydrogel for enhanced transcorneal permeation of ofloxacin

Ofloxacin, available as ophthalmic solution, has two major problems: first, it needs frequent administration every 4 hours or even every 1 hour to treat severe eye infection; second, there is formation of white crystalline deposit on cornea due to its pH-dependent solubility, which is very low at pH of corneal fluid. In order to provide a solution to previous problems, ofloxacin in this study is prepared as topically effective in situ thermosensitive prolonged release liposomal hydrogel. Two preparation procedures were carried out, leading to the formation of multilamellar vesicles (MLVs) and reverse-phase evaporation vesicles (REVs) at pH 7.4. Effects of method of preparation, lipid content, and charge inducers on encapsulation efficiency were studied. For the preparation of in situ thermosensitive hydrogel, chitosan/beta-glycerophosphate system was synthesized and used as carrier for ofloxacin liposomes. The effect of addition of liposomes on gelation temperature, gelation time, and rheological behaviors of the hydrogel were evaluated. In vitro transcorneal permeation was also determined. MLVs entrapped greater amount of ofloxacin than REVs liposomes at pH 7.4; drug loading was increased by including charge-inducing agent and by increasing cholesterol content until a certain limit. The gelation time was decreased by the addition of liposomes into the hydrogel. The prepared liposomal hydrogel enhances the transcorneal permeation sevenfold more than the aqueous solution. These results suggested that the in situ thermosensitive ofloxacin liposomal hydrogel ensures steady and prolonged transcorneal permeation, which improves the ocular bioavailability, minimizes the need for frequent administration, and decreases the ocular side effect of ofloxacin.

Corneal deposits and topical ofloxacin—the effect of polypharmacy in the management of microbial keratitis

PURPOSE

To report six cases of corneal deposits after administration of topical ofloxacin in the treatment of bacterial keratitis.

METHOD/RESULT

Six cases of microbial keratitis treated with multiple topical medications, including topical ofloxacin, resulted in corneal precipitates and poor wound healing. In five cases, the precipitates resolved with discontinuation of ofloxacin treatment. However, in one patient, some residual deposits persisted following discontinuation of ofloxacin. The cornea epithelialised, but deposits were identified subepithelially.

DISCUSSION

Fluoroquinolone antibiotic drops have been extensively used in bacterial keratitis because of their ease of availability, broad spectrum of activity, and lack of toxicity. While corneal precipitates have been reported with cases of topical ciprofloxacin and norfloxacin, little has been documented on corneal deposits and topical ofloxacin in the treatment of bacterial keratitis. The predisposing factors resulting in corneal deposits and the role of polypharmacy are important features that may impair epithelialisation. Clinical management should be aimed at reducing the toxic environment and promoting ocular surface stability.