Prospective, Randomized Clinical Trial of Povidone-Iodine 1.25% Solution Versus Topical Antibiotics for Treatment of Bacterial Keratitis.

PURPOSE: To compare povidone-iodine 1.25% ophthalmic solution with topical antibiotics for treatment of bacterial keratitis in areas of the world where use of effective topical antibiotics may not be an option. STUDY DESIGN: Randomized, controlled, investigator-masked clinical trial. METHODS: We randomized 172 individuals with bacterial keratitis to topical treatment with povidone-iodine or antibiotics (neomycin-polymyxin B-gramicidin in the Philippines; ciprofloxacin 0.3% in India). Using survival analysis, we compared intervals from start of treatment to "presumed cure" (primary outcome measure, defined as a closed epithelial defect without associated inflammatory signs) and to "recovering" (residual epithelial defect <1 mm2 with only minimal inflammation). RESULTS: Median interval to presumed cure in the Philippines was 7 days for povidone-iodine and 7 days for neomycin-polymyxin B-gramicidin (95% confidence interval [CI] for difference in median interval, -9.5 to 0.7 days) and in India was 12 days for povidone-iodine and 17 days for ciprofloxacin (95% CI, -35.2 to 3.2 days). Hazard ratio (HR) for presumed cure among those treated with povidone-iodine (vs antibiotics) was 1.46 in the Philippines (95% CI, 0.90-2.36; P = .13) and 1.70 in India (95% CI, 0.73-3.94; P = .22). Comparisons of intervals to recovering and HR for recovering also revealed no significant differences between treatment groups in either country. CONCLUSIONS: There is no significant difference between the effect of topical povidone-iodine 1.25% and topical antibiotics commonly available in the developing world for treatment of bacterial keratitis. Povidone-iodine 1.25%, which is widely available and inexpensive, can be considered for treatment of bacterial keratitis when antibiotic treatment is not practical.

Essential oils in ocular pathology: an experimental study.

INTRODUCTION: The antimicrobial activity of essential oils (EOs) has been known for ages; in particular, the EOs of Melaleuca alternifolia, Thymus vulgaris, Mentha piperita, and Rosmarinus officinalis have been used for the treatment of fungal and bacterial infections. METHODOLOGY: This study focused on the in vitro cytotoxicity to normal human conjunctiva cells and antimicrobial activity of 20 EOs. RESULTS: The oils tested showed no cytotoxic effect at very low concentrations. Rosmarinus officinalis, Melaleuca alternifolia, and Thymus vulgaris L. red thyme geraniol sel oils had good antimicrobial activity against Gram-positive and Gram-negative strains. CONCLUSIONS: The results of this study are of great interest and may have a major impact on public health, providing useful tips to optimize the therapeutic use of some natural drugs.

Keratitis due to Fusarium langsethiae: clinical profile, molecular identification, and susceptibility to antifungals.

We report a case of keratitis due to Fusarium langsethiae in a 56-year-old man. The patient presented with pain and tearing of 10 days duration in the right eye, which had sustained a paddy stalk injury. On examination, a hypopyon corneal ulcer was noted in the right eye. Multiple scrapings were obtained from the affected part of the cornea. A lactophenol cotton blue wet mount and a Gram-stained smear of scrapings were made. Scrapings were also inoculated on various culture media, including Sabouraud dextrose agar (SDA). A fungal etiology was sought by conventional microbiological techniques and polymerase chain reaction. In vitro susceptibility testing was performed by an agar dilution method. Direct microscopy of corneal scrapings revealed septate hyphae, leading to initiation of intensive topical therapy with natamycin (5 %). However, the keratitis progressed, necessitating therapeutic penetrating keratoplasty. White, powdery-like colonies, with abundant aerial mycelium, were recovered on SDA from corneal scrape material. Based on macroscopic and microscopic morphological features, the isolated fungus was initially identified as a Fusarium species. Sequence analysis of the 28S rRNA region of the fungal genome led to a specific identification of F. langsethiae. Antifungal susceptibility testing results suggested that the strain isolated was susceptible to voriconazole, ketoconazole, and itraconazole. To our knowledge, this is the first reported case of keratitis due to F. langsethiae; attention is drawn to the unique characteristics of the fungal isolate, difficulties in identification and non-responsiveness to medical therapy.

Keratoconjunctivitis caused by an unusual retained conjunctival foreign body: a frequently unrecognized entity.

PURPOSE: The purpose of this study is to describe a case series of keratoconjunctivitis caused by a retained bindi (dot) in six children who presented to a tertiary eye care facility in Southern India. PATIENTS AND METHODS: Over a period of 11 years (January 2000 and January 2012), six children (all female, ranging in age from 6 months to 3 years) were diagnosed with ocular manifestations subsequent to a retained bindi. RESULTS: All patients presented with redness, photophobia, extensive lacrimation, and blepharospasm. Two patients presented with mucopurulent conjunctivitis, three patients with suppurative keratitis and one patient presented with corneal epithelial defect. After removal of the foreign body the response to topical antibiotics was good in five of six cases, whereas one patient required therapeutic keratoplasty. CONCLUSIONS: Young children presenting with unilateral keratitis and conjunctivitis should alert the clinician to the possibility of a retained foreign body in the eye.

Keratitis due to the wood saprobic ascomycete, Auerswaldia lignicola (Family Botryosphaeriaceae), in a carpenter in India.

Keratitis due to Auerswaldia lignicola in a 32-year-old Indian male carpenter is described. At presentation, the patient reported persistent pain and tearing (left eye) in spite of topical antimicrobial therapy for more than 3 weeks. Clinically, mycotic keratitis was suspected, and direct microscopy of corneal scrapings stained by lactophenol cotton blue and Gram stains revealed broad septate hyphae. Intensive topical antifungal therapy was then given for 15 days. The keratitis continued to progress, necessitating therapeutic penetrating keratoplasty. Following the keratoplasty, there was rapid reduction in inflammation and gradual quietening of the eye. Brown-black fungal colonies resembling Lasiodiplodia theobromae were isolated from corneal scrape and corneal button (post-surgery) material on Sabouraud glucose-neopeptone agar; however, sporulation did not occur, so the morphological identification could not be confirmed. Sequence analysis of the 18S rRNA region of extracted fungal genomic DNA yielded an identification of A. lignicola Ariyawansa, J.K. Liu & K.D. Hyde; the sequence data have been deposited in GenBank (A. lignicola strain DK/V4, accession number KC866317.1). Medical management of keratitis due to such rarely reported fungal species may be difficult, necessitating surgical procedures.

Spectrum of bacterial keratitis at a tertiary eye care centre in India.

AIM: To report the aetiological spectrum and susceptibility patterns of bacteria isolated from patients with corneal ulceration. METHOD: The microbiological data of all patients with suspected infectious corneal ulceration who presented to the ocular microbiology service at this centre between 2005 and 2012 were reviewed retrospectively. RESULT: Microorganisms were recovered from 1665 (77%) of the 2170 ulcers. Bacterial isolates accounted for 1205 of the organisms isolated. The most common bacterial pathogens isolated were various species of Staphylococcus, representing 777 (64.5%), followed by Staphylococcus spp. (148; 12.3%) and Pseudomonas aeruginosa (117; 9.7%). High percentages of Gram-positive bacteria were susceptible to gatifloxacin (>94%), followed by ofloxacin and moxifloxacin. Almost 90% of Pseudomonas aeruginosa isolates were susceptible to ciprofloxacin and moxifloxacin. Sixty-two (44%) of 140 isolates of Streptococcus pneumoniae, 79 (14.8%) of 534 isolates of Staphylococcus epidermidis, and 33 (14%) of 234 isolates of Staphylococcus aureus were resistant to three or more antibiotics. CONCLUSION: Staphylococcus spp. were the most common bacterial pathogens isolated from patients with keratitis in this setting. High percentages of Gram-positive and Gram-negative bacteria were susceptible to gatifloxacin and moxifloxacin, respectively. Interestingly, a high percentage of Streptococcus pneumoniae isolates were found to be resistant to three or more antibiotics.

In vitro efficacy of contact lens solutions against various corneal fungal isolates.

PURPOSE: To investigate the susceptibility of different fungal corneal isolates to commercially available contact lens disinfecting solutions. METHODS: Thirteen filamentous fungal isolates (9 Aspergillus spp, 3 Fusarium spp, 1 Curvularia sp.) recovered from corneal infections were used. The following solutions were tested: Arion Cronos, Complete Revitalens, Dua Elite, Opti-Free Express, Regard, Oxysept Comfort, and Oxysept Comfort without catalase. Suspensions of the different fungal isolates were made in the solutions (10(6) colony-forming units/mL). After 1 h (Arion Cronos only), 6, 8, and 24 h, aliquots of suspension were removed and seeded on Sabouraud agar plates. RESULTS: After a 6-h exposure, only 3% hydrogen peroxide-based Oxysept Comfort without catalase eradicated all the fungi tested. All the other solutions were partly ineffective at killing some of the fungal isolates, even after a 24-h exposure. The worst performance was given by Regard and Dua Elite, which, after a 6-h exposure, showed growth of 12 and 10 of the 13 fungal strains tested, respectively. CONCLUSIONS: Most contact lens disinfecting solutions may not be sufficiently effective, if contact lens care systems become contaminated with filamentous fungi. In our experiment, only an exposure to 3% hydrogen peroxide without a neutralizer for at least 6 h was always able to kill an inoculum of different fungal strains.

Oxidative stress in experimental rodent corneas infected with aflatoxigenic and nonaflatoxigenic Aspergillus flavus.

PURPOSE: To seek a possible association between aflatoxigenicity and oxidative stress in keratitis caused by Aspergillus flavus in an experimental rodent model. METHODS: Wistar rats were divided into 3 groups of 6 each. Group 1 served as mock-inoculated controls. Experimental fungal keratitis was induced in group 2 and group 3 rats using aflatoxigenic and nonaflatoxigenic A. flavus conidial suspensions, respectively, and clinical features were scored for 5 days after inoculation. At this time, animals were killed, and test corneas were excised and examined histologically. Expression of IL-1ß and TNF-α genes was sought in excised corneas. Levels of malondialdehyde (MDA) and reduced glutathione (GSH) and activities of key antioxidant enzymes were measured in excised corneas and fungal mycelial homogenates. Antioxidant enzyme isoforms were sought in mycelial homogenates by native polyacrylamide gel electrophoresis. RESULTS: Mean levels of MDA and GSH and mean activities of catalase, superoxide dismutase, and glutathione peroxidase were significantly (P < 0.05) higher in a mycelial homogenate of aflatoxigenic A. flavus than in the nonaflatoxigenic mycelial homogenate. Increased numbers of well-stained isoforms were detected in aflatoxigenic mycelial homogenates. Significantly (P < 0.05) higher expression profiles of IL-1ß and TNF-α genes, MDA and GSH levels, and antioxidant enzyme activities were noted in group 2 rat corneas than in group 3 rat corneas. Clinical and histological scores suggested a more severe keratitis in group 2 rat corneas than in group 1 and group 3 rat corneas. CONCLUSIONS: Aflatoxigenicity is associated with more intense oxidative stress in experimental A. flavus keratitis.

Susceptibility of various corneal fungal isolates and Pseudomonas aeruginosa to contact lens disinfecting solutions.

INTRODUCTION: We aimed to investigate the susceptibility of a combined inoculum of Pseudomonas aeruginosa and different fungal strains to 6 soft contact lens disinfectants. METHODOLOGY: One corneal isolate of P. aeruginosa and 13 corneal fungal isolates (9 Aspergillus spp, 3 Fusarium spp, 1 Curvularia sp.) were used. The following solutions were tested: Arion Cronos, Complete RevitaLens, Dua Elite, Opti-Free Express, Regard, Oxysept Comfort, and Oxysept Comfort without catalase. The effect of the solutions was assessed on a combined inoculum of P. aeruginosa plus 1 fungal strain. Suspensions of P. aeruginosa and fungi were made in the solutions (1x106 colony-forming units/mL). After 1 hour (Arion Cronos only), 6, 8, and 24 hours, aliquots of suspension were removed and seeded on Luria-Bertani and Sabouraud agar plates. RESULTS: After 6 hours' exposure, all the solutions but Dua Elite and Oxysept Comfort eradicated P. aeruginosa. Conversely, apart from 3% hydrogen peroxide-based Oxysept Comfort without catalase, which eradicated all the fungi tested after 6 hours, all the other solutions were partly ineffective at killing some of the fungal isolates, even after 24 hours' exposure. CONCLUSIONS: Most contact lens disinfectants may be ineffective if contact lens care systems become co-contaminated with P. aeruginosa and fungi. In our experiment, only exposure to 3% hydrogen peroxide without neutralizer for at least 6 hours was always able to kill a combined inoculum of P. aeruginosa and different fungal strains.

Post-operative ocular infection due to Streptococcus dysgalactiae subspecies equisimilis.

Ocular infections due to Streptococcus dysgalactiae subsp. equisimilis are rare. In the present report, three patients with a history of uncomplicated small incision cataract surgery with intraocular lens implantation developed exogenous endophthalmitis due to Streptococcus dysgalactiae subsp. equisimilis. The identification of the organisms was confirmed by PCR for a 16S rRNA sequence specific to the species S. dysgalactiae. Intravitreal treatment of cefazolin and amikacin, in addition to topical ofloxacin and tobramycin, resulted in resolution of infection in all three patients. Our reports indicate the importance of bacterial culture and molecular identification in the diagnosis of S. dysgalactiae subsp. equisimilis infection in the eye.

Keratitis due to Chaetomium sp.

Aim. To describe keratitis due to Chaetomium sp. occurring in a 65-year-old woman who presented with a corneal ulcer with hypopyon of the right eye with a history of trauma by vegetable matter. Method. Multiple scrapings were obtained from the ulcer. A lactophenol cotton blue wet mount and a Gram-stained smear of the scrapings were made. Scrapings were also inoculated onto various culture media. Results. Direct microscopy of corneal scrapings revealed moderate numbers of septate fungal hyphae. Greenish-yellow-coloured fungal colonies with aerial mycelium were observed in culture of the corneal scrapes. On the basis of colony characteristics and conidial structure, the fungal isolate was identified as Chaetomium sp. The patient was treated with topical natamycin (5%) hourly and cyclopentolate 1% drops 3 times a day. After 4 weeks of therapy, the hypopyon had disappeared, the epithelial defect had healed, and the stromal infiltration had almost completely resolved; the visual acuity of the eye improved from hand movements to (1/2)/60. Conclusion. Fungi of the genus Chaetomium, which are rare causes of human disease (systemic mycosis, endocarditis, subcutaneous lesions), may also cause ocular lesions.

Keratitis due to Aspergillus flavus: clinical profile, molecular identification of fungal strains and detection of aflatoxin production.

PURPOSE: To document the clinical profile of patients with keratitis due to Aspergillus flavus and to elaborate on differences in the aflatoxin-producing potential of keratitis strains versus environmental strains of A. flavus. METHODS: Over a 6-month period, strains of Aspergillus flavus were isolated in culture from corneal scrape or biopsy material of patients who presented with suppurative keratitis (clinical isolates). The strains were confirmed to be A. flavus by molecular methods (amplification of the internal transcribed spacer 2 [ITS 2] region and direct sequencing followed by comparative GenBank analysis). The aflatoxin-producing potential of each strain was determined by thin-layer chromatography. The ability of each strain to form sclerotia in Czapek-Dox agar (CDA) after 7 days incubation at 30 degrees C in the dark and to produce a beige ring in yeast extract sucrose agar supplemented with methyl beta-cyclodextrin and sodium desoxycholate (YESD medium) after 3 days incubation at 30 degrees C was also assessed. For comparison, the tests were also run on 10 strains of A. flavus (identity confirmed by molecular methods) collected from local farming areas (environmental isolates). RESULTS: Aflatoxin B1 was detected in 16 (80%) of 20 culture filtrate or mycelial homogenate samples of the clinical isolates (mean concentration: 366.7+/-125.4 parts per billion [ppb]) but in only eight (40%) of 20 samples of environmental isolates (mean concentration: 306.6+/-125.4 ppb). Seven of the eight aflatoxin-producing clinical isolates and two of the four aflatoxin-producing environmental isolates formed sclerotia (>400 microm) and a beige ring in culture. CONCLUSIONS: Aflatoxin B1 was detected in a significantly higher percentage of growth samples of clinical isolates (80%) than growth samples of environmental isolates (40%) (chi(2)=6.667; p=0.0098); the therapeutic implications of this finding require further study. The production of sclerotia and a beige ring in culture appear to be useful markers of aflatoxin-producing potential in strains of A. flavus isolated from keratitis.

An outbreak of post-cataract surgery endophthalmitis caused by Pseudomonas aeruginosa.

OBJECTIVE: Infectious endophthalmitis is among the most serious complications of cataract surgery. Gram-negative bacteria, including Pseudomonas aeruginosa, are responsible for less than 30% of cases; however, their rapidity of infection and virulence often results in poor visual outcome despite prompt antibiotic treatment. The purpose of this study was to investigate an outbreak of post-cataract surgery P. aeruginosa endophthalmitis in India. DESIGN: Hospital-based case series. PARTICIPANTS: Twenty patients with acute postoperative endophthalmitis who underwent cataract surgery at one of the peripheral centers of Joseph Eye Hospital, Tiruchirapalli, Tamil Nadu, India, from February 23 to April 2, 2008. INTERVENTIONS: Vitreous aspirates and environmental surveillance specimens were inoculated for culture. Antibiotic susceptibility testing was performed by agar diffusion method. Polymerase chain reaction (PCR) with enterobacterial repetitive intergenic consensus (ERIC) primers (ERIC-PCR) was used to establish the clonal relationship between clinical and environmental isolates. MAIN OUTCOME MEASURES: Post-cataract surgery P. aeruginosa endophthalmitis. RESULTS: Pseudomonas aeruginosa was isolated from 20 eyes with postoperative endophthalmitis, the phacoemulsifier's internal tubes, the povidone-iodine solution, and the operating theater air-conditioning system. All strains were multidrug-resistant to cefazolin, chloramphenicol, tetracycline, aminoglycosides, and fluoroquinolones; conversely, most of them were susceptible to polymyxin B. Polymerase chain reaction with enterobacterial repetitive intergenic consensus primers disclosed 2 major clusters: six genetically identical clinical isolates shared 94% of similarity with the air-conditioning isolate; 11 other clinical isolates had 88% of similarity with the former strain. Despite the prompt use of intravitreal antibiotics, 10 patients had evisceration or phthisis of the affected eye. CONCLUSIONS: The outcome of cataract surgery-related P. aeruginosa endophthalmitis is poor. The detection of multidrug-resistant isolates is a serious problem, jeopardizing an appropriate choice of treatment. Polymerase chain reaction with enterobacterial repetitive intergenic consensus results strongly suggest that the main source of infection in this outbreak was the contaminated air-conditioning system. Polymerase chain reaction with enterobacterial repetitive intergenic consensus is an inexpensive, fast, reproducible, and discriminatory DNA typing tool for effective epidemiologic surveillance of clinical and environmental isolates of P. aeruginosa.

Use of chlorazol black E mounts of corneal scrapes for diagnosis of filamentous fungal keratitis.

PURPOSE: To determine whether chlorazol black E, a chitin-specific stain, can be used to detect fungal filaments in corneal scrapings and to compare its sensitivity as a diagnostic aid for fungal keratitis with that of gram and lactophenol cotton blue stains. DESIGN: Prospective study, laboratory investigation. METHODS: Between December 1, 2005 and July 31, 2006, corneal scrapes from 163 patients with ulcerative keratitis were used for culture and to prepare smears that were stained by lactophenol cotton blue, chlorazol black E, or gram stains. A diagnosis of fungal keratitis was established if fungal growth occurred on the inoculated areas of multiple culture plates. RESULTS: Fungi were isolated from corneal scrapes of 82 patients. Taking fungal culture positivity as the gold standard for diagnosis of fungal keratitis, direct microscopic examination of chlorazol black E mounts had a sensitivity of 82% and specificity of 98%; culture results and chlorazol black E results were identical in 89.6% of patients. Lactophenol cotton blue mounts and gram-stained smears had a sensitivity of 85%, specificity of 90% to 91%, and 88% agreement with culture results. CONCLUSIONS: Chlorazol black E can be used for detection of fungal filaments in corneal scrapings; however, it is less sensitive than lactophenol cotton blue and gram stains as a diagnostic aid for fungal keratitis.

Anterior chamber contamination during phacoemulsification and manual small-incision cataract surgery.

PURPOSE: To compare the per-operative contamination of anterior chamber among eyes undergoing manual small-incision cataract surgery (MSICS) and phacoemulsification (PE). DESIGN: Prospective, randomized, interventional clinical trial. METHODS: In this study conducted at a tertiary-care center in southern India, 150 eyes undergoing cataract surgery were randomly allocated to undergo MSICS (group A, 75 eyes) and PE (group B, 75 eyes). Aqueous samples were taken before and at the end of surgery. Collected material was subjected to standard microbiological analysis. No preoperative antibiotics were used, but povidone-iodine 5% drops were instilled before surgery. Main outcome measures studied were the incidence of positive cultures in aqueous samples obtained from eyes in both groups. RESULTS: The incidence of anterior chamber contamination in the MSICS group (4%) did not significantly differ from the PE group (2.7%; P = .65). CONCLUSIONS: Incidence of anterior chamber contamination is similar among eyes undergoing MSICS and PE.

Comparison of topical gatifloxacin 0.3% and ciprofloxacin 0.3% for the treatment of bacterial keratitis.

PURPOSE: To compare the bacteriologic and clinical efficacy of gatifloxacin and ciprofloxacin for the treatment of bacterial keratitis. DESIGN: Prospective, randomized clinical trial. METHODS: A total of 104 eyes of 104 patients with bacterial keratitis seen at a tertiary eye-care center were randomized to treatment with gatifloxacin 0.3% eyedrops (GAT group, 50 eyes) or ciprofloxacin 0.3% eyedrops (CIP group, 54 eyes). Patients and the treating physician were masked to the antibiotic being used. Main outcome measure studied was healing of the ulcer. Patients lost to follow-up before complete healing were excluded from further analysis. RESULTS: A significantly higher proportion of ulcers in the GAT group exhibited complete healing compared with those in the CIP group (39 eyes [95.1%] vs 38 [80.9%]; P=.042). Gatifloxacin demonstrated a significantly better action than ciprofloxacin against gram-positive cocci in vitro (P<.001), and the percentage of ulcers caused by these pathogens that healed in the GAT group was significantly better than in the CIP group (P=.009). Mean time taken for healing of ulcer and the efficacy against gram-negative bacteria did not significantly differ between the two groups. CONCLUSIONS: Gatifloxacin had a significantly better action against gram-positive cocci both in vitro and in vivo when compared with ciprofloxacin. In view of these organisms being the leading cause of keratitis worldwide, gatifloxacin may be a preferred alternative to ciprofloxacin as the first-line monotherapy in bacterial keratitis.

Trimethoprim-sulphamethoxazole therapy in Nocardia keratitis.

PURPOSE: To describe the clinical features, microbiological features and treatment outcome of nine patients with Nocardia keratitis treated with topical trimethoprim- sulphamethoxazole drops. METHODS: Retrospective review of nine patients with culture-proven Nocardia keratitis. RESULTS: Nine patients with Nocardia keratitis were treated with topical trimethoprim-sulphamethoxazole drops. The average duration of treatment was 25 +/- 9 days. Five of the nine patients presented with superficial ulcers with margins studded with yellowish white discrete pinhead sized infiltration; the other four patients had deep stromal infiltration. Complete healing of the ulcer was achieved in six out of the nine patients with topical trimethoprim- sulphamethoxazole alone or in combination with ciprofloxacin 0.3% eye drops. CONCLUSION: Topical application of trimethoprim-sulphamethoxazole appears to be effective therapy for superficial keratitis due to Nocardia.