Therapeutic response time of topical voriconazole 1% and intrastromal voriconazole 0.05% versus topical natamycin 5% monotherapy in Fusarium keratitis in rabbit.

BACKGROUND: Fungal keratitis can be more difficult to treat than bacterial keratitis with worse outcomes. OBJECTIVE: To evaluate the therapeutic response time of topical voriconazole combined with intrastromal voriconazole, and topical natamycin on Fusarium keratitis. METHODS: The stroma of corneas of twelve New Zealand White rabbits was inoculated with Fusarium sp spores. Seven days after inoculation, they were divided into 2 groups randomly. Group A was treated with topical natamycin 5% for 21 days. Group B was treated with intrastromal voriconazole 0.05% single injection at the beginning of treatment, continued with topical voriconazole 1% for 21 days. Clinical evaluations for epithelial defect size and clinical scores in each group were performed on 1st, 3rd, 7th, 10th, 14th and 21st days after treatment. Mycological examinations were performed before and after the treatment. RESULTS: After treatment, there was no statistically significant difference between natamycin and voriconazole in reducing epithelial defect size at first, second or third week after treatment (P = .15; P = .39; and P = .90). The clinical scores on both groups also showed no statistically significant differences at first, second and third weeks after treatment (P = .24; P = .09; and P = .32). Qualitative mycological evaluation before and after the treatment showed no statistically significant difference in KOH examination (P = 1; P = 1) and culture in Sabouraud dextrose agar (P = 1; P = 1). CONCLUSION: Intrastromal voriconazole injection combined with topical voriconazole seems to give similar response time but not earlier in improving clinical presentation of Fusarium keratitis as topical natamycin.

Gellan Gum Based Sol-to-Gel Transforming System of Natamycin Transfersomes Improves Topical Ocular Delivery.

Short precorneal residence time and poor transocular membrane permeability are the major challenges associated with topical ocular drug delivery. In the present research, the efficiency of the electrolyte-triggered sol-to-gel-forming system of natamycin (NT) transfersomes was investigated for enhanced and prolonged ophthalmic delivery. Transfersomes were optimized by varying the molar ratios of phospholipid, sorbitan monostearate (Span) and tocopheryl polyethylene glycol succinate (TPGS). NT transfersome formulations (FNs) prepared with a 1:1 molar ratio of phospholipid-to-Span and low levels of TPGS showed optimal morphometric properties, and were thus selected to fabricate the in situ gelling system. Gellan gum-based (0.3% w/v) FN-loaded formulations (FNGs) immediately formed an in situ gel in the simulated tear fluid, with considerable viscoelastic characteristics. In vitro cytotoxicity in corneal epithelial cells and corneal histology studies demonstrated the ocular safety and cytocompatibility of these optimized formulations. Transcorneal permeability of NT from these formulations was significantly higher than in the control suspension. Moreover, the ocular disposition studies of NT, from the FNs and FNGs, in New Zealand male albino rabbits demonstrated the superiority of the electrolyte-sensitive FNGs in terms of NT delivery to the ocular tissues.

Mycotic Antimicrobial Localized Injection: A Randomized Clinical Trial Evaluating Intrastromal Injection of Voriconazole.

PURPOSE: To determine if there is a benefit to adjuvant intrastromal voriconazole (ISV) injections for primary treatment of filamentous fungal keratitis. DESIGN: Outcome-masked, randomized controlled clinical trial. PARTICIPANTS: Patients with moderate vision loss resulting from a smear-positive fungal ulcer. METHODS: Study eyes were randomized to topical natamycin plus ISV injection versus topical natamycin alone. MAIN OUTCOME MEASURES: The primary outcome of the trial was microbiological cure on 3-day repeat culture analysis. Secondary outcomes included microbiological cure on 7-day repeat culture analysis; 3-week and 3-month best spectacle-corrected visual acuity; infiltrate or scar size or both; rate of perforation; therapeutic penetrating keratoplasty (TPK); and other adverse events. RESULTS: A total of 151 patients with smear-positive ulcers were screened and 70 were enrolled at Aravind Eye Hospital, Pondicherry, India. Baseline cultures grew Fusarium in 19 samples (27%), Aspergillus in 17 samples (24%), and other filamentous fungi in 19 samples (27%) and showed negative results in 13 samples (19%). Those randomized to ISV injection had 1.82 times the odds of 3-day culture positivity after controlling for baseline culture status (95% confidence interval [CI], 0.65-5.23; P = 0.26, bias-corrected logistic regression) and 1.98 times the odds of positive 7-day culture results, after controlling for baseline culture status (95% CI, 0.69-5.91; P = 0.20, bias-corrected logistic regression). Those randomized to ISV injection showed 0.5 logMAR lines (approximately 0.5 Snellen lines) of decreased visual acuity (95% CI, -2.6 to 3.6 lines; P = 0.75) and 0.55 mm worse infiltrate or scar size or both at 3 months after controlling for baseline values (95% CI, -0.13 to 1.25; P = 0.11). Intrastromal voriconazole injections showed a 2.85-fold increased hazard of perforation after controlling for baseline infiltrate depth (95% CI, 0.76-10.75; P = 0.12) but no difference in the rate of TPK (hazard ratio, 0.95; 95% CI, 0.44-2.04; P = 0.90). CONCLUSIONS: There seems to be no benefit to adding ISV injections to topical natamycin in the primary treatment of moderate to severe filamentous fungal ulcers. Studies consistently suggest that voriconazole has a limited role in the treatment of filamentous fungal ulcers.

Fungal keratitis: An overview of clinical and laboratory aspects.

Mycotic keratitis or keratomycosis is a fungal infection with global distribution. The dominant aetiology of this disease varies based on geographical origin, socioeconomic status, and climatic condition. Generally, Aspergillus spp. and Fusarium spp. are common in tropical and subtropical regions and Candida spp. are dominant in temperate areas. Demonstration of fungal elements in microscopic examination besides the isolation of fungi in culture is the gold standard of laboratory diagnosis. As the culture is a time-consuming procedure, other approaches such as in vivo confocal microscopy which produces real-time imaging of corneal tissue and molecular techniques have been developed to facilitate rapid diagnosis of fungal keratitis. The first choice of treatment is topical natamycin, although topical amphotericin B is the best choice for Aspergillus and Candida keratitis. Regarding the diversity of fungal aetiology and the emergence of drug resistance in some genera and species, proper identification using molecular methods and antifungal susceptibility testing could provide useful data. Furthermore, as the better efficacy of combination therapy in comparison to monotherapy is reported, in vitro determination of interactions between various drugs seem informative. This review aims to provide a general and updated view on the aetiology, risk factors, epidemiology, clinical and laboratory diagnosis, and management of fungal keratitis.

Fungal keratitis due to Schizophyllum commune: an emerging pathogenic fungus.

Fungal keratitis due to Schizophyllum commune is very rare. In this study, we report the clinical and microbiological profile of five patients with fungal keratitis due to S. commune. Direct microscopic examination of corneal scrapings from all five patients showed septate branching hyaline fungal filaments. Similarly, in all five patients Sabouraud dextrose agar (SDA) plates inoculated with corneal scrapings showed white, cottony colonies on the second day of incubation. Lactophenol cotton blue stained wet preparation of 7-day-old colonies on SDA revealed clamp connections and no spores. The fungus was identified by its characteristic clamp connections, fan-shaped bracket fruiting body with pinkish-grey longitudinally split-radiating gills. The phenotypic identification of one of the five isolates further conformed by ITS sequencing. Treatment outcome was available for two of the five patients; in these two patients, the keratitis resolved with topical natamycin.

Effects of Antifungal Soaked Silicone Hydrogel Contact Lenses on Candida albicans in an Agar Eye Model.

PURPOSE: To evaluate the effects of two commercial silicone hydrogel contact lenses (CLs) soaked with natamycin (NA) or fluconazole (FL) on the growth of Candida albicans in an in vitro eye model. METHODS: Three-D printed molds were used as a cast for making eye-shaped models comprising potato dextrose agar. Senofilcon A (SA) and lotrafilcon B (LB) CLs were incubated with either 2 mL of NA or FL at a concentration of 1 mg/mL for 24 hr. To simulate a fungal infection, the eye models were coated with C. albicans. The drug-soaked lenses were placed on top of the eye models. Seven experimental conditions were examined: (1) NA-SA, (2) NA-LB, (3) FL-SA, (4) FL-LB, (5) SA, (6) LB, and (7) control-no lens. At specified time points (t=1, 8, 16, 24, 48 hr), the agar eyes from each experimental condition were removed from the incubator and photographed. The yeast cells from the 24 and 48 hr time point were also analyzed using light microscopy. RESULTS: At 24 and 48 hr, there was considerable growth observed for all conditions except for the NA-SA and NA-LB conditions. When observed under the microscope at 24 and 48 hr, the morphology of the yeast cells in the FL-SA and SA condition were similar to that of the control (oval shaped). There was limited hyphae growth observed for LB and significant visible hyphae growth for the NA-LB group. For NA-SA, NA-LB, and FL-LB groups, the cells were significantly smaller compared with the control. CONCLUSIONS: For NA-SA and NA-LB, there was limited growth of C. albicans observed on the eye models even after 48 hr. Under the microscope, the cell morphology differ noticeably between each testing condition, and is dependent on drug-lens combinations.

Formulation and antifungal performance of natamycin-loaded liposomal suspensions: the benefits of sterol-enrichment.

The aim of this study is to develop and evaluate food-grade liposomal delivery systems for the antifungal compound natamycin. Liposomes made of various soybean lecithins are prepared by solvent injection, leading to small unilamellar vesicles (<130 nm) with controlled polydispersity, able to encapsulate natamycin without significant modification of their size characteristics. Presence of charged phospholipids and reduced content of phosphatidylcholine in the lecithin mixture are found to be beneficial for natamycin encapsulation, indicating electrostatic interactions of the preservative with the polar head of the phospholipids. The chemical instability of natamycin upon storage in these formulations is however significant and proves that uncontrolled leakage out of the liposomes occurs. Efficient prevention of natamycin degradation is obtained by incorporation of sterols (cholesterol, ergosterol) in the lipid mixture and is linked to higher entrapment levels and reduced permeability of the phospholipid membrane provided by the ordering effect of sterols. Comparable action of ergosterol is observed at concentrations 2.5-fold lower than cholesterol and attributed to a preferential interaction of natamycin-ergosterol as well as a higher control of membrane permeability. Fine-tuning of sterol concentration allows preparation of liposomal suspensions presenting modulated in vitro release kinetics rates and enhanced antifungal activity against the model yeast Saccharomyces cerevisiae.

Cell penetrating peptides as efficient nanocarriers for delivery of antifungal compound, natamycin for the treatment of fungal keratitis.

PURPOSE: Enhancing the penetration ability of the antifungal drug natamycin, known to possess poor penetration ability through the corneal epithelium, by complexing with cell penetrating peptides. METHODS: The drug, natamycin was conjugated to a cell penetrating peptide, Tat-dimer (Tat2). The uptake ability of the conjugate in human corneal epithelial cells and its antifungal activity against filamentous fungi, F.solani has been elucidated. RESULTS: The cellular penetration ability of natamycin increased upon conjugation with Tat2. The conjugation between natamycin and Tat2 also lead to enhanced solubility of the drug in aqueous medium. The antifungal activity of the conjugate increased two- folds in comparison to unconjugated natamycin against clinical isolates of F.solani. CONCLUSION: The formation of CPP-natamycin complex is clinically significant as it may enhance the bioavailability of natamycin in corneal tissues and aid in efficient management of fungal keratitis.

Evaluation of corneal collagen cross-linking as an additional therapy in mycotic keratitis.

BACKGROUND: To report the treatment outcomes of mycotic keratitis with collagen cross-linking. DESIGN: Retrospective study. PARTICIPANTS: Patients with smear-positive moderate mycotic keratitis. METHODS: A retrospective case-file analysis was performed to identify cases of moderate mycotic keratitis treated with and without additional collagen cross-linking, in addition to intensive topical antifungal therapy. Patients in which collagen cross-linking was performed on the day of presentation (group 1) were compared with patients who received medical treatment alone in the form of 5% natamycin eye drops (group 2). MAIN OUTCOME MEASURES: The primary outcome measure was the time taken for resolution of infection. RESULTS: Overall, 41 cases were included for analysis (group 1, 20 cases; group 2, 21 cases). Mean age of the patients was comparable in both groups (46.5 ± 17.01 vs. 41.2 ± 20.7 years; P = 0.36). Average infiltrate size was 16.35 ± 6.8 mm(2) in group 1 and 17.09 ± 7.4 mm(2) in group 2 (P = 0.83). Overall, Aspergillus was the most commonly isolated organism (n = 4 group 1; n = 6 group 2). Resolution of infection was observed in 18 cases (90%) in group 1 and 18 (85.71%) cases in group 2. The average healing time was 30.85 ± 26.6 days in group 1, while it was 31.28 ± 19.97 days in group 2 (P = 0.94). Final best-corrected visual acuity in group 1 was 1.13 ± 0.55 and 1.25 ± 0.46 in group 2 (P = 0.46). A tectonic keratoplasty was performed in two cases in group 1 and three cases in group 2 (P = 1.00). CONCLUSIONS: In our study, additional collagen cross-linking treatment did not have any advantage over medical management in cases with moderate mycotic keratitis.

Nanomicelles empower natamycin in treating fungal keratitis: An in vitro, ex vivo and in vivo study.

Fungal infections of cornea are important causes of blindness especially in developing nations with tropical climate. However, the challenges associated with current treatments are responsible for poor outcome. Natamycin is the only FDA-approved antifungal drug to treat fungal keratitis, but unfortunately due to its poor water solubility, it is available as suspension. The marketed suspension (5% Natamycin) has rapid precorneal clearance, poor corneal permeability, a higher frequency of administration, and corneal irritation due to undissolved suspended drug particles. In our study, we developed clear and stable natamycin-loaded nanomicelles (1% Natcel) to overcome the above challenges. We demonstrated that 1% Natcel could permeate the cornea better than 5% suspension. The developed 1% Natcel was able to provide sustained release for up to 24 h. Further, it was found to be biocompatible and also improved the mean residence time (MRT) than 5% suspension in tears. Therefore, the developed 1% Natcel could be a potential alternative treatment for fungal keratitis.

Comparative evaluation of topical versus intrastromal voriconazole as an adjunct to natamycin in recalcitrant fungal keratitis.

OBJECTIVE: To compare the efficacy of topical voriconazole and topical natamycin with that of intrastromal voriconazole and topical natamycin in patients with recalcitrant fungal keratitis. DESIGN: Randomized clinical trial. PARTICIPANTS: Forty eyes of 40 patients with fungal keratitis (positive smear or culture results or both) larger than 2 mm, involving up to two thirds of the stromal depth, and not responding to topical natamycin therapy for 2 weeks were recruited. INTERVENTION: The patients were randomized to receive either topical 1% voriconazole therapy (n = 20) or intrastromal injections of voriconazole 50 µg/0.1 ml (n = 20). The patients in both groups continued topical natamycin 5% every 4 hours until the ulcer healed. MAIN OUTCOME MEASURES: Primary outcome measure was best spectacle-corrected visual acuity (BSCVA) 3 months after intervention, and secondary outcome measures were time to healing and the size of the scar. RESULTS: The patients in both groups had comparable baseline parameters. The mean BSCVA after treatment was 1.295 ± 0.5 logarithm of the minimum angle of resolution (logMAR) units in the topical group and 1.692 ± 0.29 logMAR units in the intrastromal group. The visual acuity after treatment was significantly better in the topical voriconazole group (P = 0.008). Nineteen patients receiving topical voriconazole and 16 patients who were given intrastromal voriconazole healed with therapy. CONCLUSIONS: Topical voriconazole seems to be a useful adjunct to natamycin in fungal keratitis not responding to topical natamycin. Intrastromal injections did not offer any beneficial effect over topical therapy.

In vitro uptake and release of natamycin from conventional and silicone hydrogel contact lens materials.

OBJECTIVES: To investigate the uptake and release of the antifungal ocular drug, natamycin from commercially available conventional hydrogel (CH) and silicone hydrogel (SH) contact lens (CL) materials and to evaluate the effectiveness of this delivery method. METHODS: Five commercial SH CLs (balafilcon A, comfilcon A, galyfilcon A, senofilcon A, and lotrafilcon B) and four CH CLs (etafilcon A, omafilcon A, polymacon, vifilcon A) were examined in this study. These lenses were incubated with natamycin solubilized in dimethyl sulfoxide, and the release of the drug from these lenses, in Unisol 4 pH 7.4 at 32±1°C, was determined using UV-visible spectrophotometry at 305 nm over 24 hours. RESULTS: There was a significant uptake of natamycin between 0 hour and 24 hours (P<0.05) for all CL materials. However, there was no significant difference between any of the lens materials, regardless of their composition (P>0.05). There was a significant difference in release between all the SH materials (P<0.05) and CH materials (P<0.05). All CL materials showed a significant increase in the release of natamycin until 1 hour (P<0.05), which was followed by a plateau (P>0.05). Overall, the release of natamycin was higher in CH than SH lenses (P<0.001). CONCLUSIONS: All CLs released clinically relevant concentrations of natamycin within 30 minutes, but this release reached a plateau after approximately 1 hour. Further CL material development will be necessary to produce a slow and sustained drug releasing device for the delivery of natamycin.

[Fungal keratitis caused by Scedosporium apiospermum: first report from Turkey]. / Scedosporium apiospermum'a Bagli Fungal Keratit: Ülkemizden Ilk Olgu.

Fungal keratitis, an eye infection with poor prognosis, is difficult to treat and can lead to loss of vision. Among filamentous fungi Scedosporium spp. rarely lead to fungal keratitis. Here we present a case of keratitis caused by Scedosporium apiospermum. A 61-year-old female patient was admitted to our hospital with the complaints of right eye pain and decreased vision after a foreign body trauma to the right eye. The patient was diagnosed as keratitis by biomicroscopic examination. Conjunctival swabs collected from both eyes were inoculated onto sheep blood agar, chocolate agar, eosin methylene blue agar and Sabouraud dextrose agar. Corneal scrapings from the right eye were inoculated onto the same solid media by "C-streak" method, and in brain-heart-infusion broth by immersion. While gram-stained smears of conjunctival swabs showed no significant finding, smears of corneal scrapings revealed abundant neutrophils and profuse septate hyphae. Fungal keratitis was diagnosed and topical enhanced amphotericin B (0.5 mg/ml) therapy was initiated with netilmicin sulfate and oxytetracycline HCl plus polymyxin B sulfate. At the 10th day of therapy a mold growth was detected in corneal scraping cultures and was identified microscopically as S.apiospermum. Based on the relevant literature, therapy was changed to enhanced topical voriconazole (2 mg/ml) applied hourly, plus systemic voriconazole administration. At the third day of treatment, reduction of epithelial defect and decline in the focus of keratitis were observed. In the following days, however, a progression occurred in the focus of keratitis and 5% natamycin ophthalmic suspension was added to the therapy. Since the patient did not respond to any of the medical treatments, therapeutic penetrating keratoplasty was planned; yet, the patient refused the operation and was discharged with her own request. As far as the local literature was concerned, this is the first report of keratitis caused by S.apiospermum in Turkey. Though a very rare causative agent of keratitis, S.apiospermum is generally resistant to antifungal therapy and often require surgical treatment. Especially in patients with predisposing factors, this organism should be kept in mind as a potential causative agent and relevant microbiological examinations should be performed.

Fungal scleral keratitis caused by Phomopsis phoenicicola.

We report a case of scleral keratitis caused by Phomopsis phoenicicola. Pterygium surgery was a predisposing factor, and the patient was treated with natamycin and fluconazole eye drops and oral fluconazole. The fungus was identified by sequencing of the internal transcribed spacer (ITS) region of the fungal ribosomal DNA (rDNA) locus and confirmed on the basis of its typical pycnidia and conidia.

Voriconazole versus natamycin as primary treatment in fungal corneal ulcers.

BACKGROUND: To evaluate the efficacy of topical 1% voriconazole versus 5% natamycin in treatment of fungal corneal ulcers. DESIGN: A prospective, randomized pilot study in a tertiary care hospital. PARTICIPANTS: Thirty patients of microbiologically proven fungal keratitis divided randomly in two groups of 15 patients each. METHODS: Two groups were treated with either 5% natamycin (group A) or 1% voriconazole (group B) topically as a primary treatment for fungal keratitis. The mean size, depth of infiltrate and LogMAR visual acuity at presentation were comparable in both groups (P > 0.05). Patients were followed up for minimum of 10 weeks or till complete resolution of ulcer, whichever was later. Cultures to identify the causative organisms were performed. MAIN OUTCOME MEASURE: Time of resolution of the ulcer. RESULTS: Twenty-nine of the total 30 patients showed complete resolution. Average time of resolution and gain in LogMAR visual acuity was 24.3 days and 1.12 in group A and 27.2 days and 0.77 in group B. These were comparable in the two groups (P > 0.05%). Aspergillus spp. (40%) and Curvularia spp. (30.0%) were found to be most common isolates. CONCLUSION: Topical 1% voriconazole was found to be safe and effective drug in primary management of fungal keratitis, its efficacy matching conventional natamycin. There was no added advantage of using topical 1% voriconazole over topical natamycin as primary treatment in fungal keratitis.

Pseudodendritic fungal epithelial keratitis in an extended wear contact lens user.

PURPOSE: Pseudodendritic keratitis in a contact lens wearer is generally associated with acanthamoeba keratitis. We report a case of isolated pseudodendritic fungal epithelial keratitis that occurred in an extended wear contact lens user. METHODS: A 48-year-old woman was evaluated in our clinic for a 36-hour history of left eye pain. She wore extended wear soft contact lenses and frequently rinsed her eyes with tap water. Her left cornea had a paracentral 3-mm area of epithelium with raised ridges in a pseudodendritic pattern. The underlying corneal stroma was normal. A therapeutic and diagnostic corneal scraping of the lesion was performed and sent for Gomori methenamine silver (GMS) staining. The clinical concern was for epithelial acanthamoeba keratitis. RESULTS: The GMS staining revealed septate fungal hyphae within sheets of corneal epithelium. The patient was started on frequent alternating natamycin (5%) and amphotericin B (0.15%) antifungal eyedrops and exhibited a rapid clinical response. Her keratitis completely resolved, and her vision returned to her baseline of 20/25. Corneal fungal cultures showed no growth. CONCLUSIONS: Our case is an extremely unusual presentation of fungal keratitis, which rarely presents as a pseudodendritic epithelial keratitis. There are two previous similar case reports initially misdiagnosed as acanthamoeba keratitis. Clinicians should be aware that isolated fungal epithelial keratitis can present as a distinct entity and should be considered in the differential diagnosis of pseudodendritic keratitis. The GMS staining is an excellent diagnostic test in a patient presenting with pseudodendritic keratitis because it allows rapid diagnosis of acanthamoeba and fungal infections.

[External otitis in children: etiology and principles of therapy].

External otitis accounts for 21 to 25% of all inflammatory ear diseases. This paper presents the original data providing a deeper insight into etiology of this disease taking into consideration the great variety of its pathogenic agents, the possibility of development of mixed forms, and changes of whether conditions at the peak of morbidity. In addition, the results of assessment of the efficacy of Pimafucort designed for both mono- and combined therapy of the disease of interest are reported.

Nanocubosomal based in situ gel loaded with natamycin for ocular fungal diseases: development, optimization, in-vitro, and in-vivo assessment.

Natamycin (NT) is a synthetic broad-spectrum antifungal used in eye drops. However, it has low solubility and high molecular weight, limiting its permeation, and generally causes eye discomfort or irritation when administered. Therefore, the present study aimed to develop an ophthalmic in situ gel formulation with NT-loaded cubosomes to enhance ocular permeation, improve antifungal activity, and prolong the retention time within the eye. The NT-loaded cubosome (NT-Cub) formula was first optimized using an I-optimal design utilizing phytantriol, PolyMulse, and NT as the independent formulation factors and particle size, entrapment efficiency %, and inhibition zone as responses. Phytantriol was found to increase particle size and entrapment efficiency %. Higher levels of PolyMulse slightly increased the inhibition zone whereas a decrease in particle size and EE% was observed. Increasing the NT level initially increased the entrapment efficiency % and inhibition zone. The optimized NT-Cub formulation was converted into an in situ gel system using 1.5% Carbopol 934. The optimum formula showed a pH-sensitive increase in viscosity, favoring prolonged retention in the eye. The in vitro release of NT was found to be 71 ± 4% in simulated tear fluid. The optimum formulation enhanced the ex vivo permeation of NT by 3.3 times compared to a commercial formulation and 5.2 times compared to the NT suspension. The in vivo ocular irritation test proved that the optimum formulation is less irritating than a commercial formulation of NT. This further implies that the developed formulation produces less ocular irritation and can reduce the required frequency of administration.

[Characteristic appearance of early-stage Acanthamoeba keratitis].

PURPOSE: To clarify the characteristic appearances of early-stage Acanthamoeba keratitis (AK) and to investigate the effects of topical steroids on those appearances. SUBJECT AND METHODS: This study involved 25 eyes of 24 patients diagnosed as early-stage AK at Kyoto Prefectural University of Medicine between October 2002 and June 2008. All patients were contact lens wearers, and 23 patients (96%) were referred from other hospitals. Clinical findings in the medical records of all patients were analyzed retrospectively. RESULTS: Radial keratoneuritis was observed in 20 of 25 eyes (80%), and pseudodendritic lesions were observed in 15 eyes (60%). Only 1 eye (4%) showed neither of these two findings. Of the 10 eyes treated with topical steroids until the first presentation at our hospital, 6 eyes manifested radial keratoneuritis and/or pseudodendritic lesions after the discontinuation of that treatment. The visual prognosis was good in both groups, with or without topical steroid treatment. CONCLUSIONS: We found that radial keratoneuritis and pseudodendritic lesions are characteristic appearances of early-stage AK, and that topical steroid treatment might mask these characteristic findings.

Reduced administration frequency for the treatment of fungal keratitis: a sustained natamycin release from a micellar solution.

Background: Natamycin is the only topical ophthalmic antifungal drug approved by the Food and Drug Administration (FDA) of the United States, but has unsatisfactory factors such as high dosing frequency.Methods: We report the synthesis and preparation of self-assembled poly(ethylene glycol)-block-poly(glycidyl methacrylate) (PEG-b-PGMA) micelles. These nanoparticles exhibit sustained delivery of a hydrophobic natamycin by topical administration on eye due to the hydrolysable properties of PGMA segments of micelle. Hydrolysis of glycidyl groups within a physiologically relevant environment provides an additional driving force for drug release by generation of hydrophilic hydroxyl groups to 'push' the encapsulated hydrophobic drug away from the resultant hydrophilic domains and into surrounding environment.Results: In vitro and in vivo results revealed that the self-assembled micelles and the encapsulated natamycin were not cytotoxic and the released drug have strong antifungal ability to Candida albicans. Importantly, sustained natamycin release from micelles leads to the reduced administration frequency of natamycin from 8 times per day to 3 times per day in rabbits suffering from fungal keratitis (FK).Conclusion: This study demonstrates a facile method that can greatly reduce dosing frequency of natamycin administration and thus improve long-term patient compliance.