Intracameral moxifloxacin: in vitro safety on human ocular cells

Safety of intracameral application of moxifloxacin and dexamethasone (Vigadexa®) after phacoemulsification surgery

BACKGROUND

Intracameral antibiotics, such as moxifloxacin and cefuroxime, are safe to corneal endothelial cells and effective prophylaxis of endophthalmitis after cataract surgery. Corneal endothelial cells decrease in density after cataract surgery. Any substance used in the anterior chamber may affect corneal endothelial cells and lead to a greater decrease in density. This study wants to determine the percentage of endothelial cell loss after cataract extraction by phacoemulsification with off-label intracameral injection of moxifloxacin and dexamethasone (Vigadexa®).

METHODS

An observational retrospective study was performed. The clinical records of patients undergoing cataract surgery by phacoemulsification plus intracameral injection of Vigadexa® were analyzed. Endothelial cell loss (ECL) was calculated using preoperative and postoperative endothelial cell density. The relation of endothelial cell loss with cataract grade using LOCS III classification, total surgery time, total ultrasound time, total longitudinal power time, total torsional amplitude time, total aspiration time, estimated fluid usage, and cumulative dissipated energy (CDE) was studied using univariate linear regression analysis and logistic regression analysis.

RESULTS

The median loss of corneal endothelial cells was 4.6%, interquartile range 0 to 10.4%. Nuclear color and CDE were associated with increased ECL. ECL>10% was associated with age and total ultrasound time in seconds.

CONCLUSIONS

The endothelial cell loss after the intracameral use of Vigadexa® at the end of cataract surgery was similar to the reported in other studies of cataract surgery without the use of intracameral prophylaxis for postoperative endophthalmitis (POE). This study confirmed the association of CDE and nuclear opalescence grade with postoperative corneal endothelial cell loss.

Consensus and controversies in the science of endophthalmitis management: Basic research and clinical perspectives

Infectious endophthalmitis is a severe intraocular infection caused by bacteria, or less commonly by fungi. It can occur after penetrating eye procedures, trauma, or the spread of infection from contiguous structures or via emboli from distant organs. Because of the time-critical nature of the treatment, endophthalmitis is treated with the clinical diagnosis and modified by the microbiological report of the intraocular contents. The current strategy for managing endophthalmitis relies on pre-clinical literature, case series, and one large multi-center randomized clinical trial on post-cataract surgery endophthalmitis. Culture-susceptibility of the microorganisms from undiluted vitreous guides the definitive treatment in non-responsive cases. Strategies to reduce the incidence of endophthalmitis after penetrating eye procedures have been developed concurrently with refined means of treatment. Despite these advances, outcomes remain poor for many patients. Although consensus articles have been published on managing endophthalmitis, treatment patterns vary, and controversies remain. These include (1) the use of newer methods for early and precise microbiological diagnosis; (2) the choice of intravitreal antibiotics; (3) the need for systemic therapy; (4) early and complete vitrectomy. Here, we review the current consensus and address controversies in diagnosing and managing endophthalmitis. This review is intended to familiarize physicians and ophthalmologists with different aspects of endophthalmitis management to make informed decisions.

Macular and choroidal thickness after intracameral moxifloxacin for prevention of postcataract endophthalmitis

PURPOSE

To determine any changes in macular or choroidal thickness associated with the use of intracameral moxifloxacin as postcataract endophthalmitis prophylaxis.

SETTING

University of Campinas, Campinas, São Paulo, Brazil.

DESIGN

Prospective, randomized, partially masked, single-site clinical trial.

METHODS

Phacoemulsification surgery patients in the experimental group (Group A) received a 0.03 mL intracameral injection of undiluted moxifloxacin from a sealed bottle immediately after phacoemulsification surgery (150 μg in 0.03 mL-Vigamox solution), whereas the control group (Group B) did not. Investigators evaluated in masked fashion macular and choroidal thickness using spectral-domain optical coherence tomography preoperatively and postoperatively.

RESULTS

A total of 93 patients were included (48 in Group A and 45 in Group B). Baseline parameters were similar between the groups. Either of the 2 parameters assessed differed statistically between the groups or preoperatively vs postoperatively. On postoperative day 30, central macular thickness was 8.85 ± 14.78 μm in Group A and 10.26 ± 22.44 μm in Group B (P = .7232); choroidal thickness as measured by enhanced depth imaging (EDI) was 1.45 ± 16.13 μm in Group A and 3.74 ± 16.15 in Group B (P = .5017). On postoperative day 60, central macular thickness was 19.53 ± 39.28 μm in Group A and 17.14 ± 53.68 μm in Group B (P = .8363); EDI was 5.08 ± 21.96 μm in Group A and 5.24 ± 15.8 in Group B (P = .9752).

CONCLUSIONS

The application of intracameral injection of 0.03 mL of undiluted 0.5% moxifloxacin during phacoemulsification surgery as endophthalmitis prophylaxis induced no changes in macular or choroidal thickness.

Toxic Anterior Segment Syndrome with Intracameral Moxifloxacin: Case Report and Review of the Literature

A case of severe anterior segment toxicity secondary to high-volume, undiluted intracameral moxifloxacin for endophthalmitis prophylaxis is reported. We examine the other reported cases of toxicity after intracameral moxifloxacin, as well as iris depigmentation and transillumination syndromes after oral and topical fluoroquinolone exposure. Additionally, we review the literature on safety, efficacy, and appropriate dosing of intracameral antibiotics with a focus on moxifloxacin.

Evaluation of moxifloxacin-induced cytotoxicity on human corneal endothelial cells

Moxifloxacin hydrochloride (MXF) is widely used for the prevention of bacterial endophthalmitis after intraocular surgeries. However, the safety issue of intracameral injection of MXF for human corneal endothelial cells (HCECs) is still debatable. In this study, we investigated concentration-dependent cytotoxicity (0.05–1 mg/ml) of MXF for immortalized HCECs (B4G12 cell) and the underlying mechanism. Reactive oxygen generation (ROS) and cell viability after MXF exposure was measured. Flow cytometric analysis and TUNEL assay was used to detect apoptotic HCECs after MXF exposure. Ultrastructure of damaged HCECs by MXF was imaged by transmission electron microscope. Western blot analysis and caspase 2, 3 and 8 analysis were used to reveal the underlying mechanism of MXF induced damage in HCECs. We found that MXF induced dose-dependent cytotoxicity in HCECs. MXF exposure increased ROS generation and induced autophagy in HCECs. Increased LDH release represented the cellular membrane damage by MXF. In addition, caspases activation, Bax/Bcl-xL-dependent apoptosis pathway and apoptosis inducing factor nuclear translocation were all involved in MXF induced HCECs’ damage, especially after exposure to high dose of MXF (0.5 and 1.0 mg/ml). These findings suggest that MXF toxicity on HCECs should be thoroughly considered by ophthalmologists when intracameral injection of MXF is planned.

Commonly used intracameral antibiotics for endophthalmitis prophylaxis: A literature review

Endophthalmitis is a serious complication of cataract surgery that occurs in thousands of patients each year. To decrease the incidence of postoperative endophthalmitis, many surgeons inject intracameral antibiotics (cefuroxime, moxifloxacin, and vancomycin) routinely at the end of surgery. A large number of recently published retrospective studies and large database analyses have reported decreased endophthalmitis rates with routine antibiotic use, and the only prospective, multicenter, randomized trial performed by the European Society of Cataract and Refractive Surgery demonstrated that intracameral cefuroxime decreases the incidence of postoperative endophthalmitis. Routine cefuroxime use has become common in many European countries, whereas moxifloxacin is the most commonly used drug in India, and vancomycin use predominates in Australia. The decision regarding whether or not to use intracameral prophylaxis and the drug that is selected varies considerably throughout the world because of antibiotic availability and cost, and the spectrum of causative organisms. Adverse events due to intracameral antibiotics are infrequent, but complications such as hemorrhagic occlusive retinal vasculitis have been reported. Because additional prospective, comparative trials have not been performed, a consensus regarding best practices to prevent postoperative endophthalmitis has not been reached. Additionally, many surgeons do not routinely use intracameral antibiotics because they believe them unnecessary with modern aseptic techniques, small incision surgery, and shorter operating times. We discuss the most commonly used intracameral antibiotics, present the risks and potential benefits of this approach, and highlight challenges with drug compounding and safety.

Toxicities of and inflammatory responses to moxifloxacin, cefuroxime, and vancomycin on retinal vascular cells

Prophylactic intracameral injection of antibiotics is commonly used to prevent endophthalmitis after cataract surgery. However, devastating visual complications have been reported including hemorrhagic occlusive retinal vasculitis (HORV).To determine the toxic and inflammatory effects of moxifloxacin, cefuroxime, and vancomycin on human retinal vascular cells, human retinal vascular endothelial cells (RVEC) and pericytes were exposed to three antibiotics, and the adverse effects were assessed by membrane damage, loss of intrinsic esterase activity, kinetic cell viability, and inflammatory cytokine secretion. Their retinal toxicity was examined by live/dead assays after an intravitreal injection of the three antibiotics into mice eyes. In vascular cells in culture, membrane damage and loss of esterase activity were induced after exposure to the three antibiotics. The toxic effects were most obvious after moxifloxacin (RVEC, ≥125 μg/mL; pericytes, ≥1000 μg/mL) at 24 h. Cefuroxime also reduced esterase activity and the membrane integrity of vascular cells but were less toxic than moxifloxacin. Kinetic cell viability testing showed that 500 μg/mL of moxifloxacin exposure induced significant decrease (29%) in the viability as early as 1 h. When the inflammatory effects of the antibiotics were examined, a significant induction of IL-8 was observed especially by RVECs after exposure to cefuroxime or vancomycin which was exacerbated by L-alanyl-γ-D-glutamyl-meso-diaminopimelic acid (Tri-DAP), a NOD1 ligand. Intravitreal injections in mice showed that cefuroxime and vancomycin caused retinal and vascular toxicity extending to the inner nuclear layers. Collectively, moxifloxacin causes immediate damage to retinal vascular cells in vitro, while cefuroxime and vancomycin induced significant inflammatory effects on vascular endothelial cells and caused retinal toxicity. Surgeons need to be cautious of the toxicity when antibiotics are used prophylactically especially by intravitreal administration.

Penetration of 0.3% ciprofloxacin, 0.3% ofloxacin, and 0.5% moxifloxacin into the cornea and aqueous humor of enucleated human eyes

We aimed to quantify the penetration of ciprofloxacin, ofloxacin, and moxifloxacin into the cornea and aqueous humor of cadaver eyes. A total of 60 enucleated eyes, not eligible for corneal transplantation, were divided into three groups and immersed in commercial solutions of 0.3% ciprofloxacin, 0.3% ofloxacin, or 0.5% moxifloxacin for 10 min. Whole corneas and samples of aqueous humor were then harvested and frozen, and drug concentrations analyzed by liquid chromatography tandem mass spectrometry. The mean corneal concentration of moxifloxacin was twice as high as ofloxacin, and the latter was twice as high as ciprofloxacin. The mean concentration of moxifloxacin in the aqueous humor was four times higher than the other antibiotics, and the mean concentrations of ciprofloxacin and ofloxacin were statistically similar. The amount of drug that penetrated the anterior chamber after a 10-min immersion was far below the safe limit of endothelial toxicity of each preparation. Moxifloxacin demonstrated far superior penetration into the cornea and anterior chamber of cadaver eyes compared to ciprofloxacin and ofloxacin. One should not expect endothelial toxicity with the commercial eye drops of ciprofloxacin, ofloxacin, and moxifloxacin that reach the anterior chamber through the cornea.

Moxifloxacin Concentration and Proteomic Analysis of Aqueous Humor in Human Uveitis Associated with Oral Moxifloxacin Therapy

PURPOSE

The aim was to report the aqueous humor moxifloxacin concentration and proteome profile of an individual with bilateral uveitis-like syndrome with pigment dispersion.

METHODS

Multiple reactions monitoring mass spectrometry quantified the aqueous concentration of moxifloxacin in the affected individual. Shotgun proteomic analysis performed via liquid chromatography tandem mass spectrometry (LC-MS/MS) defined the protein profile in the affected individual and unaffected control samples.

RESULTS

Moxifloxacin was present at higher than expected levels in aqueous humor 18 days following oral administration. One-third of the proteins were identified by significantly lower spectral counts in the aqueous of the individual with moxifloxacin associated uveitis compared to the unaffected control.

CONCLUSION

Moxifloxacin was detected in aqueous humor 18 days following the completion of oral administration. These results suggest that moxifloxacin toxicity may be responsible for the uveitis-like syndrome with pigment dispersion syndrome induced by moxifloxacin therapy.

[Ocular toxicity of intracamerally injected antibacterial and antifungal drugs (experimental and morphological study)]

OBJECTIVE

To study anterior eye segment toxicity of variously diluted brand name and generic antibiotic and antifungal drugs, including domestically produced generics (Moxifloxacin, asketin cefuroxime, amikacin, gentamicin, Diflucan, and amphotericin B), experimentally injected into the anterior chamber.

MATERIAL AND METHODS

A total of 13 Chinchilla rabbits were included in the experiment. Group 1 (6 rabbits) received sterile intracameral injections of 0.2 ml antibiotics and antifungals in concentrations suitable for intravenous administration (Moxifloxacin 1.6 mg/ml, Diflucan 2 mg/ml, and the following generics: asketin cefuroxime 125 mg/ml, amikacin 50 mg/ml, gentamicin 40 mg/ml, amphotericin B 50 mg/m). BSS was injected into the fellow eye for control. Group 2 (7 rabbits) also received sterile intracameral injections of 0.2 ml antibiotics and antifungals, which were the same as for group 1 but highly diluted (Moxifloxacin 150 μg/ml and 500 μg/ml, Diflucan 10 μg/ml, asketin cefuroxime 1 mg/ml, gentamicin 200 μg/ml, amikacin 400 μg/ml, amphotericin B 10 μg/ml).

RESULTS

There were no toxic effects in group 1 after BSS and Moxifloxacin 1.6 mg/ml injections into the anterior chamber. However, high concentrations of other antibiotic and antifungal drugs were associated with changes in the corneal endothelium of various severity (from cytoplasmic swelling of the endothelial cells to their complete desquamation), as well as fibrin exudation in the posterior chamber. In group 2 neither of injected drugs caused toxic, allergic, or inflammatory reactions according to histopathological examination.

CONCLUSION

The experiment proved safety of the intracameral route of administration for highly diluted medications from the list and also demonstrated the absence of toxic reaction after intracameral injection of Moxifloxacin 1.6 mg/ml.

Safety of prophylactic intracameral moxifloxacin ophthalmic solution after cataract surgery in patients with penetrating keratoplasty

AIM

To determine the safety of prophylactic intracameral moxifloxacin after cataract surgery in patients with penetrating keratoplasty (PKP).

METHODS

In this retrospective study of consecutive patients who had phacoemulsification cataract surgery after PKP, were treated with intracameral moxifloxacin 0.5% ophthalmic solution (0.5 mg/0.1 mL). The main outcome measures were anterior chamber reaction, best corrected visual acuity (BCVA), corneal endothelial cell count (ECC), and central corneal thickness (CCT).

RESULTS

Fifty-five patients were recruited (26 males, 29 females). The mean age was 54.36±4.97y (range 45-64y). All eyes had improved postoperative BCVA. The mean BCVA was 0.25 preoperatively and 0.57 postoperatively, which was statistically significant (P<0.001). One eye had 3+, 7 eyes had 2+, 12 eyes had 1+ and 8 eyes had trace amount of aqueous cells on the first day after surgery. All eyes had no anterior chamber cells at subsequent follow up examinations. Effective phacoemulsification time was 4.33±1.01s. The mean ECC was 2340.20 cells/mm(2) preoperatively and 1948.75 cells/mm(2) 1mo postoperatively (P<0.001). The increase of 21.09 µm in postoperative pachymetry 1mo after surgery was statistically significant (P<0.001).

CONCLUSION

No untoward effects were observed after intracameral injection of moxifloxacin (0.5 mg/0.1 mL) in terms of anterior chamber reaction, CCT, ECC, and visual rehabilitation at the conclusion of cataract surgery in patients with PKP.

Comparison of toxicities of moxifloxacin, cefuroxime, and levofloxacin to corneal endothelial cells in vitro

PURPOSE

To evaluate and compare the toxic effects of moxifloxacin, cefuroxime, and levofloxacin on human corneal endothelial cells in vitro and determine the safe intracameral concentrations for them.

SETTING

Tottori University, Tottori, Japan.

DESIGN

Experimental study.

METHODS

Human corneal endothelial cells in culture were exposed to moxifloxacin, cefuroxime, and levofloxacin at concentrations up to 2000 μg/mL. Evaluation of membrane damage was determined by ethidium homodimer-1 uptake and cell viability, by intrinsic esterase activity. The inhibitory effects of the 3 antibiotics on the constitutive secretion of interleukin-6 (IL-6) by human corneal endothelial cells were determined by enzyme-linked immunosorbent assay.

RESULTS

The acute effects (6 hour) of the 3 antibiotics on membrane damage and cell death were dose-dependent for moxifloxacin and levofloxacin (≥ 500 μg/mL). For cefuroxime, membrane damage was not observed at 6 hours and only slight damage was detected at 24 hours at concentrations higher than 500 μg/mL. The half maximum inhibitory concentrations on cell viability of moxifloxacin, levofloxacin, and cefuroxime were 487 μg/mL, 578 μg/mL, and 1600 μg/mL, respectively. The inhibitory effects of the 3 antibiotics on the constitutive secretion of IL-6 were observed at 15.6 μg/mL or higher, indicating the antibiotics can impair the secretion of the protective cytokine even at low concentrations.

CONCLUSIONS

Moxifloxacin at more than 500 μg/mL caused damage to the cell membranes of corneal endothelial cells; even higher concentrations decreased cell viability. Considering the lower minimum inhibitory concentration for inhibiting 90% growth by moxifloxacin, intracameral moxifloxacin at 500 μg/mL or less is recommended for prophylactic use.

FINANCIAL DISCLOSURE

Dr. Inoue is a medical advisor to Alcon Japan Ltd. No author has a financial or proprietary interest in any material or method mentioned.

Safety of intracameral injection of moxifloxacin using total replacement technique (bag and chamber flushing)

PURPOSE

To assess the safety of intracameral injection of moxifloxacin (MFLX) using the total replacement technique [bag and chamber (BC) flushing].

METHODS

The anterior chamber including the area behind the intraocular lens was irrigated and replaced using BC flushing. In Group A, 36 patients received balanced salt solution irrigation in the right eye and intracameral MFLX (150 μg/mL: 33-fold dilution of 0.5% eye drops) in the left eye. In Group B, 33 patients received intracameral MFLX in the right (500 μg/mL: 10-fold dilution) and left eyes (150 μg/mL: 33-fold dilution). Visual acuity, intraocular pressure, corneal endothelial cell density, corneal thickness, and foveal thickness were recorded before and up to 3 months after surgery.

RESULTS

In either group, there were no statistically significant differences between the right and left eyes with respect to visual acuity, intraocular pressure, corneal endothelial cell count, and foveal thickness before and at 3 months after surgery. There was no difference in corneal thickness before and at 3 months after surgery. In patients who received 500 μg/mL MFLX during surgery, central corneal thickness at 1 week after surgery was significantly reduced.

CONCLUSIONS

In the present study, there was no adverse effect associated with intracameral injection of 150-500 μg/mL MFLX. Moreover, our results supported the safety of BC flushing. Thus, BC flushing, which can irrigate the inside of the capsular bag and attain stable antibiotic concentrations, appears to be a favorable technique for intracameral injection of MFLX.

Does moxifloxacin alter oxidant status in the cornea? An experimental study

OBJECTIVE

In this experimental study, we investigated the possible effects of intracameral moxifloxacin on oxidative stress parameters and endothelial cell morphology in corneal tissue.

METHODS

In total, 30 rats were randomly assigned to three groups of 10 rats: the sham group (Group 1, n = 10); the control group (Group 2), where balanced salt solution (BSS) was administered at a dose of 0.01 cc (n = 10); and the treatment group (Group 3), where moxifloxacin was administered at a dose of 0.05 mg/0.01 cc (n = 10). Total antioxidant status (TAS) and total oxidant status (TOS) in corneal tissue and blood samples were measured and the oxidative stress index (OSI) was calculated. Also, corneal tissue histopathology was evaluated with caspase-3 and caspase-8 staining. Apoptotic activity was also evaluated.

RESULTS

In blood samples, TAS, TOS, and OSI levels were not statistically significantly different (all p > 0.05). Compared with the sham and control groups, TOS and OSI levels in cornea tissue were significantly different in the moxifloxacin group (all p < 0.05). However, compared with the control group, no statistically significant difference was found in the sham group (all p > 0.05). Compared with the sham and control groups, apoptotic activity was higher in the moxifloxacin group, in both immunohistochemical staining for caspase-3 and caspase-8.

CONCLUSIONS

Intracameral moxifloxacin injection seems to be safe systemically, but it may have toxic effects on corneal tissues, as suggested by oxidative stress parameters and a histopathological evaluation.

Cohort study of intracameral moxifloxacin in postoperative endophthalmitis prophylaxis

We conducted a cohort study to evaluate post-cataract surgery endophthalmitis rates in relation to prophylactic intracameral moxifloxacin administration. A total of 2332 patients (2674 eyes) who underwent phacoemulsification by a single surgeon from January 2007 through December 2012 were included in the study. A total of 1056 eyes did not receive intracameral prophylactic moxifloxacin and the antibiotic was injected in 1618 eyes. The incidence of presumed postoperative endophthalmitis in the 2 groups was calculated. The rate of presumed infectious endophthalmitis after cataract surgery between January 2007 and June 2009 (without intracameral moxifloxacin) was 0.094%. The rate in the second period, from July 2009 to December 2012 (with prophylactic intracameral moxifloxacin), was 0%. In our patients, a decline in the incidence of presumed infectious postoperative endophthalmitis appeared to be associated with the application of intracameral moxifloxacin.

Antiproliferative and cytotoxic properties of moxifloxacin on rat retinal ganglion cells

Abstract Purpose: To evaluate the antiproliferative and cytotoxic properties of moxifloxacin on cultured rat retinal ganglion cells (RGC5).

MATERIALS AND METHODS

Rat retinal ganglion cells were exposed to various concentration of moxifloxacin (5-1500 μg/mL). For antiproliferative properties, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) test was performed. Cellular cytotoxicity was assessed by using the Live/Dead viability/cytotoxicity assay and analyzed by fluorescence microscopy after 24 and 72 h of incubation, respectively.

RESULTS

Neither cytotoxic nor antiproliferative effect of moxifloxacin was observed below 50 μg/mL on RGC5 cells after 24 and 72 h of incubation. At higher concentrations of moxifloxacin (150 μg/mL, 500 μg/mL, and 1500 μg/mL (p < 0.001)) the number of viable cells and the proliferation rate of RGC5 were significantly reduced.

CONCLUSIONS

These results suggest a dose-dependent cytotoxic and antiproliferative effect of moxifloxacin on RGC5. Therefore, intracameral application of moxifloxacin should be used cautiously in patients with increased risk of retinal ganglion cells damage, particularly in glaucoma patients.

In vitro moxifloxacin drug interaction with chemotherapeutics: implications for retinoblastoma management

Retinoblastoma (RB) is a common malignant intraocular tumor primarily affecting children. Multidrug resistance (MDR) proteins (P-gp and MRPs) mediated chemoresistance have been considered as a major cause of treatment failure in treatment of RB. Ocular cells have shown good tolerability against moxifloxacin (MFX). Hence, the aim of present study was to investigate the effect of moxifloxacin on the functionality of MDR proteins. Furthermore, we have also examined an interaction of MFX with anticancer agents (Topotecan, etoposide and vinblastine) for RB treatment. For interaction of MFX with efflux transporter, model cell lines transfected with the efflux transporters (MDCK-MDR1 and MDCK-MRP2) were used to perform uptake and bi-directional transport experiments. Modulation of anticancer induced cell cytotoxicity, pro-inflammatory cytokines (IL-6 and IL-8) release and caspase-3 enzyme activity in presence of MFX was also evaluated. Result indicates that MFX is a substrate of both MDR1 and MRP2 efflux transporters. Furthermore elevation of anticancer uptake and bi-directional transport, reduction in IC50 cytotoxic value and modulation of antiproliferative and cytokines release in presence of MFX by anticancer agents was observed. Our results demonstrate that MFX may not only modulate the permeability of anticancer agents at efflux sites but it may also potentiate antiproliferative activity of anticancer agents in retinoblastoma cells. This study may be further extended to explore in vivo outcome of this finding.

Efficacy and safety of prophylactic intracameral moxifloxacin injection in Japan

PURPOSE

To report endophthalmitis rates after cataract surgery and the incidence of complications after intracameral moxifloxacin injection.

SETTING

Nineteen clinics in Japanese institutions.

DESIGN

Retrospective survey cohort study.

METHODS

The number of surgeries and endophthalmitis cases in the past 4 years before and after the introduction of intracameral moxifloxacin was evaluated. The survey was performed by mail or interview in February 2013.

RESULTS

All institutions used total-replacement administration rather than small-volume injection. At 3 institutions, 50 to 100 μg/mL moxifloxacin; at 9 institutions, 100 to 300 μg/mL moxifloxacin; and at 7 institutions, 500 μg/mL moxifloxacin was administered. The highest concentration (500 μg/mL) was administered in 14,124 cases. Endophthalmitis cases occurred 1 month or sooner postoperatively in 8 of 15,958 cases (ie, 1 in 1955) without intracameral moxifloxacin administration and in 3 of 18,794 cases (ie, 1 in 6265) with intracameral moxifloxacin administration.

CONCLUSIONS

Intracameral moxifloxacin (50 to 500 μg/mL) administration decreased the risk for endophthalmitis by 3-fold. In more than 18,000 cases, moxifloxacin administration of 500 μg/mL or less did not result in severe complications, such as toxic anterior segment syndrome or corneal endothelial cell loss.

Moxifloxacin modifies corneal fibroblast-to-myofibroblast differentiation

BACKGROUND AND PURPOSE

Fibroblast-to-myofibroblast differentiation is associated with scarring, an important issue in corneal surgery. Moxifloxacin (MOX), commonly applied to prevent post-operative infection, would benefit more if it modifies fibroblast-to-myofibroblast differentiation other than antimicrobial activity. Our purpose was to explore whether MOX has anti-fibrotic effect in human corneal fibroblasts (HCFs).

EXPERIMENTAL APPROACH

HCFs were incubated in MOX-containing medium concurrently with TGF-β1 (co-treatment), before (pretreatment) or after (post-treatment) adding TGF-β1. HCF contractility was evaluated with a type I collagen gel contraction assay. Expression of α-smooth muscle actin (α-SMA), Smad2, phospho-Smad2-Ser467, Smad4 and Smad7 was determined by immunoblotting. Formation of α-SMA-positive filaments and distribution of active Smad2 were observed under confocal microscopy. Expression of TGF-β receptor types I (TGFBR1) and II (TGFBR2) was assessed with flow cytometry.

KEY RESULTS

MOX did not affect gel contractility or α-SMA filament formation in HCFs without TGF-β1 stimulation. MOX did, however, retard HCF-containing gel contractility and α-SMA filament formation following TGF-β1 stimulation in the pretreatment and co-treatment groups but not in the post-treatment group. MOX blocked the expression of Smad2, phospho-Smad2-Ser467 and TGFBR1 under TGF-β1 incubation. Additionally, MOX enhanced Smad7 expression in TGF-β1-incubated HCFs, but did not interfere with TGF-β-triggered Smad2 nuclear translocation or Smad4 expression.

CONCLUSIONS AND IMPLICATIONS

MOX inhibited TGF-β-induced fibroblast-to-myofibroblast differentiation via blocking TGFBR1 and enhancing Smad7 expression. MOX should be used before or during surgery to achieve these effects. These results suggest a de novo mechanism by which MOX participates in corneal wound healing.

Assessment of vitreous drug concentration in the porcine eye following intracameral injection or irrigation with moxifloxacin

Introduction

Posterior capsule rupture causes instant vitreous contamination, resulting in endophthalmitis. However, transfer of intracameral moxifloxacin (MFLX) to the vitreous has not been examined in detail. We investigated vitreous antibiotic concentrations following intracameral MFLX in both ruptured and intact posterior capsular eyes.

Methods

Experiment 1: Intraocular lenses were inserted into 21 extracted porcine eyes by one of the following three methods: (1) Irrigation: Throughout surgery, 33-fold diluted MFLX irrigation solution (150 μg/mL) was used; (2) Bag and chamber flushing: After surgery, the anterior chamber and area behind the intraocular lenses were irrigated with 30-fold diluted MFLX (167 μg/mL) using a 5 mL syringe; (3) Simple injection: Tenfold diluted MFLX (50 μg in 0.1 mL) was injected intracamerally at the conclusion of surgery. The eyeballs were frozen and the anterior, central, and posterior portions of the vitreous were cubed. After defrosting, concentrations were measured using high-performance liquid chromatography. Experiment 2: The same procedure was conducted for 18 eyes in which the posterior capsule had been ruptured.

Results

Experiment 1: Transfer of intracameral MFLX to the anterior vitreous was approximately 1% (1.56–2.20 μg/mL) regardless of the administration method. Experiment 2: MFLX reached a high concentration in the vitreous with irrigation solution administration (maximum 30.22 μg/mL). The concentrations reached by simple injection or flushing were significantly less than those obtained by irrigation.

Conclusion

With an intact posterior capsule, intracameral MFLX exhibited limited effects on vitreous concentration. Despite the fact that the risk of infection clearly increases in cases of ruptured capsule, no special infection prevention protocol has been proposed. It was confirmed that irrigation solution caused vitreous contamination in ruptured eyes within only a short irrigation time. In this case, intracameral administration did not necessarily achieve preventive concentrations for endophthalmitis, but it appears that an effective drug concentration can be achieved in the vitreous by the administration of irrigation solution.

Ocular pharmacokinetics, safety and efficacy of intracameral moxifloxacin 0.5% solution in a rabbit model

PURPOSE

This study was carried out to determine the ocular pharmacokinetics, efficacy and potential endothelial toxicity of moxifloxacin (MF) after a single intracameral bolus injection of 500 µg/0.1 ml in a rabbit model.

MATERIALS AND METHODS

Forty-eight eyes of 24 New Zealand White Rabbits were separated into six groups, each including four rabbits. 0.1 ml of 0.5% intracameral moxifloxacin (500 µg) injection was injected to the right eyes and 0.1 ml of balanced salt solution to the left eyes (control). Aqueous humor (AH) and vitreous samples were collected at the 0.5th, 1st, 3rd, 6th, 12th and 24th hours from both eyes of group 1, 2, 3, 4, 5 and 6, respectively. MF concentrations were determined by high performance liquid chromatography. These were compared with the minimum inhibitory concentrations (MIC) and mutant prevention concentrations (MPC) for frequent endophthalmitis pathogens. Electron and light microscopical evaluation of the corneas were performed.

RESULTS

Moxifloxacin reaches higher concentration than the MIC of all common endophthalmitis pathogens in the AH and exceeds the mutant prevention concentration levels for Streptococcus pneumonia, Streptococcus viridans, flouroquinolone susceptible Coagulase-negative staphylococcus and flouroquinolone susceptible Staphylococcus aureus for 6 h. The half-life of moxifloxacin in the AH was 2.2 h. Electron and light microscopic evaluation revealed no noticeable sign of toxicity.

CONCLUSIONS

Peroperative intracameral moxifloxacin injection for endophthalmitis prophylaxis is a safe and effective method in uncomplicated phacoemulsification surgery.

Bag and chamber flushing: a new method of using intracameral moxifloxacin to irrigate the anterior chamber and the area behind the intraocular lens

BACKGROUND

Intracameral moxifloxacin is currently administered by injecting small doses (0.05-0.2 mL) of either undiluted or diluted solutions. It is difficult to ensure delivery of small amounts of antibiotic into the area behind the intraocular lens (IOL). Moreover, the anterior chamber pressure decreases as the tip of irrigation is removed, often leading to contaminated fluid flowing into the chamber. Conventional intracameral injection administers the diluted antibiotic without irrigating the recontaminated anterior chamber. Therefore, we developed a method of intracameral moxifloxacin delivery which flushes both the anterior chamber and the area behind the IOL immediately after surgery.

METHODS

Surgical technique (bag and chamber flushing = BC flushing): After removing the viscosurgical device, 1.5-1.8 mL diluted moxifloxacin was injected. Both the anterior chamber and the area behind the IOL were irrigated by lifting the IOL edge so that a stream of solution could circulate behind the IOL. Experiment 1 (pig): The anterior chamber was filled with condensed milk, and irrigated with 150-fold diluted moxifloxacin (33.3 μg/mL) in six eyes (BC flushing) to observe the irrigating effect. The anterior aqueous humor was sampled. Experiment 2 (human): A conventional intracameral injection (500 μg/mL) or BC flushing (33.3 μg/mL) was followed by sampling 0.1 mL of the anterior aqueous humor in six eyes each. High-performance liquid chromatography was performed to determine antibiotic levels.

RESULTS

Experiment 1: The antibiotic concentration in the anterior chamber was 33.0 μg/mL (99.0 % was displaced). The area behind the IOL was not effectively irrigated without inserting the cannula tip. Experiment 2: The final antibiotic concentration was 152.3 μg/mL using the conventional method and 29.4 μg/mL using the BC flushing (88.3 % was displaced).

CONCLUSION

BC flushing technique enables surgeons to completely displace the anterior chamber including the posterior IOL surface, resulting in effective irrigation and a stable antibiotic concentration in virtually all cases.

[Intracameral moxifloxacin: a safe option for endophthalmitis prophylaxis? In vitro safety profile for intraocular application]

BACKGROUND

Moxifloxacin (Vigamox), a 4th-generation fluoroquinolone, covers most isolates causing endophthalmitis. It is safe and effective for systemic and topical use; however, only very limited data are available on prophylactic intracameral administration to prevent endophthalmitis. This study investigated the safety of Vigamox for intracameral application in a cell-culture model.

METHODS

The endothelial toxicity of moxifloxacin (Vigamox) was evaluated in cultured human corneas. Primary human retinal pigment epithelium cells (RPEs), trabecular meshwork cells (TMCs), lens epithelium cells (LECs), and corneal endothelial cells (CECs) were treated with concentrations of Vigamox. Toxic effects were evaluated after 24 h (MTT assay and live-dead assay). By treating TMC, CEC, and RPE cells either with oxidative stress or tumor necrosis factor-alpha (TNF-a), lipopolysaccharide (LPS), and interleukin-6 (IL-6), the effects of moxifloxacin on cellular viability under conditions of inflammation were investigated.

RESULTS

No corneal endothelial toxicity could be detected after 30 days of treatment with moxifloxacin 500 microg/ml. Primary RPEs, TMCs, LECs, and CECs showed adverse effects on proliferation and viability only at concentrations higher than 150 microg/ml moxifloxacin. After preincubation with TNF-a, LPS, and IL-6 for 24 h and subsequent treatment with moxifloxacin at concentrations of 10-150 microg/ml for 24 h, no significant decrease in proliferation or viability was observed. H2O2 exposure did not increase cellular toxicity

CONCLUSION

Vigamox did not show significant toxicity on primary RPEs, TMCs, LECs, CECs, or human corneal endothelium at concentrations up to 150 microg/ml. The MIC90 of moxifloxacin for pathogens commonly encountered in endophthalmitis is known to be in the range of 0.25-2.5 microg/ml. Therefore, intracameral use of Vigamox at concentrations up to 150 microg/ml may be safe and effective for preventing endophthalmitis after intraocular surgery.

Endophthalmitis: Pathogenesis, clinical presentation, management, and perspectives

Endophthalmitis is a rare but sight-threatening complication that can occur after ocular surgery or trauma or as a consequence of systemic infection. To optimize visual outcome, early diagnosis and treatment are essential. Over recent decades, advances in hygienic standards, improved microbiologic and surgical techniques, development of powerful antimicrobial drugs, and the introduction of intravitreal antibiotic therapy have led to a decreased incidence and improved management of endophthalmitis. However, endophthalmitis still represents a serious clinical problem. This review focuses on current principles and techniques for evaluation and treatment of endophthalmitis. In addition, it addresses recent developments regarding antimicrobial treatment and prophylaxis of infectious endophthalmitis.