A human corneal ulcer caused by Thelazia callipaeda in Southwest China: case report.

In this study, we describe a rare human case with corneal ulcer caused by thelaziosis in a 69-year-old man in Southwest China. A male nematode was discovered and removed from the patient's right eye with a long spicule and further identified by sequencing mitochondrial cox1 gene. The ophthalmologic and molecular biological evidence demonstrates the corneal ulcer caused by T. callipaeda infection, which is mainly distributed in Asian and European countries. Most T. callipaeda infections are emerged in the conjunctiva, leading to conjunctivitis. To the best knowledge of the authors, corneal ulcers caused by T. callipaeda have not been reported yet.

Evaluation of the sensitivity to chlorhexidine, voriconazole and itraconazole of T4 genotype Acanthamoeba isolated from Mexico.

Free-living amoebae of the genus Acanthamoeba are the etiological agents of cutaneous lesions, granulomatous amoebic encephalitis (GAE) and amoebic keratitis (AK), which are chronic infections with poor prognosis if not diagnosed promptly. Currently, there is no optimal therapeutic scheme to eradicate the pathologies these protozoa cause. In this study we report the morphological and molecular identification of three species of the genus Acanthamoeba, belonging to T4 group; A. polyphaga isolated from the corneal ulcer of a patient sample of AK case; A. castellanii isolated from the contact lens of an AK patient and A. palestinensis obtained from a soil sample. The in vitro activity of chlorhexidine, itraconazole and voriconazole drugs against trophic stage was also evaluated through a colorimetric assay based on the oxidation-reduction of alamar blue. The strains in the study were sensitive to the evaluated drugs; although when determining the 50% inhibitory concentration (IC50) statistically significant differences were observed. A. castellanii showed to be highly sensitive to voriconazole (0.66 ±â€¯0.13 µM) but the least sensitive to chlorhexidine and itraconazole (8.61 ±â€¯1.63 and 20.14 ±â€¯4.93 µM, respectively), A. palestinensis showed the highest sensitivity to itraconazole (0.502 ±â€¯0.11 µM) and A. polyphaga expressed moderate sensitivity to chlorhexidine and itraconazole and lower sensitivity to voriconazole (10.10 ±â€¯2.21 µM). These results showed that species of the genus Acanthamoeba express different sensitivity to the tested drugs, which could explain the problems surrounding the establishment of a treatment of choice in the infections caused by these amoebae. We consider that although chlorhexidine and itraconazole show good activity on these amoebae and have been used in cases of AK in Mexico with acceptable results, voriconazole should be considered as the first therapeutic option of future Acanthamoeba infections that will be diagnosed in our country.

Prospective Study of the Diagnostic Accuracy of the In Vivo Laser Scanning Confocal Microscope for Severe Microbial Keratitis.

PURPOSE: To determine the diagnostic accuracy of in vivo confocal microscopy (IVCM) for moderate to severe microbial keratitis (MK). DESIGN: Double-masked prospective cohort study. PARTICIPANTS: Consecutive patients presenting to Aravind Eye Hospital, Madurai, India, between February 2012 and February 2013 with MK (diameter ≥3 mm, excluding descemetocele, perforation, or herpetic keratitis). METHODS: Following examination, the corneal ulcer was scanned by IVCM (HRT3/RCM, Heidelberg Engineering, Heidelberg, Germany). Images were graded for the presence or absence of fungal hyphae or Acanthamoeba cysts by the confocal microscopist who performed the scan (masked to microbial diagnosis) and 4 other experienced confocal graders (masked to clinical features and microbiology). The regrading of the shuffled image set was performed by 3 graders, 3 weeks later. Corneal-scrape samples were collected for microscopy and culture. MAIN OUTCOME MEASURES: The main outcome measures were sensitivity, specificity, and positive and negative predictive values of IVCM compared with those of a reference standard of positive culture or light microscopy. Sensitivities and specificities for multiple graders were pooled and 95% confidence intervals calculated using a bivariate random-effects regression model. RESULTS: The study enrolled 239 patients with MK. Fungal infection was detected in 176 (74%) and Acanthamoeba in 17 (7%) by microbiological methods. IVCM had an overall pooled (5 graders) sensitivity of 85.7% (95% confidence interval [CI]: 82.2%-88.6%) and pooled specificity of 81.4% (95% CI: 76.0%-85.9%) for fungal filament detection. For Acanthamoeba, the pooled sensitivity was 88.2% (95% CI: 76.2%-94.6%) and pooled specificity was 98.2% (95% CI: 94.9%-99.3%). Intergrader agreement was good: κ was 0.88 for definite fungus; κ was 0.72 for definite Acanthamoeba. Intragrader repeatability was high for both definite fungus (κ: 0.88-0.95) and definite Acanthamoeba classification (κ: 0.63-0.90). IVCM images from 11 patients were considered by all 5 graders to have a specific organism present (10 fungus, 1 Acanthamoeba) but had negative results via culture and light microscopy. CONCLUSIONS: Laser scanning IVCM performed with experienced confocal graders has high sensitivity, specificity, and test reproducibility for detecting fungal filaments and Acanthamoeba cysts in moderate to large corneal ulcers in India. This imaging modality was particularly useful for detecting organisms in deep ulcers in which culture and light microscopy results were negative.

Degeneration and Regeneration of Subbasal Corneal Nerves after Infectious Keratitis: A Longitudinal In Vivo Confocal Microscopy Study.

PURPOSE: To investigate the longitudinal alterations of subbasal corneal nerves in patients with infectious keratitis (IK) during the acute phase, cessation of treatment, and the recovery phase by in vivo confocal microscopy (IVCM). DESIGN: Prospective, longitudinal, case-control, single-center study. PARTICIPANTS: Fifty-six eyes of 56 patients with the diagnosis of bacterial (n=28), fungal (n=15), or Acanthamoeba (n=13) keratitis were included in the study. Thirty eyes of 30 normal volunteers constituted the control group. METHODS: Corneal sensation and serial IVCM of the central cornea were performed prospectively using the Heidelberg Retina Tomograph 3/Rostock Cornea Module (Heidelberg Engineering, Heidelberg, Germany). The IVCM images were assessed at 3 time points: at the acute phase (first visit to the cornea service), at cessation of antimicrobial treatment, and up to 6 months after the resolution of infection. MAIN OUTCOME MEASURES: Total nerve number and length, main nerve trunks, branching, and corneal sensation were assessed during the follow-up period. RESULTS: Corneal nerves were reduced significantly during the acute phase in eyes with IK compared with controls across all subgroups, with total nerve length of 5.47±0.69 mm/mm2 versus 20.59±1.06 mm/mm2 (P<0.0001). At the cessation of treatment, corneal nerves in patients with IK had regenerated, including total nerve length (8.49±0.94 mm/mm2; P=0.02) and nerve branch length (4.80±0.37 mm/mm2; P=0.005). During the recovery phase, after resolution of infection, corneal nerves regenerated further, including total nerve length (12.13±1.97 mm/mm2; P=0.005), main nerve trunk length (5.80±1.00 mm/mm2; P=0.01), and nerve branch length (6.33±0.76 mm/mm2; P=0.003) as compared with the acute phase, but were still significantly lower when compared with controls (P<0.05 for all parameters). Corneal degeneration and regeneration correlated with corneal sensation (r=0.47; P=0.0009). CONCLUSIONS: Patients with IK who sustain profound loss of corneal nerves during the acute phase of infection demonstrate increased corneal nerve density during the first 6 months after the resolution of infection. However, despite significant nerve regeneration, corneal nerve density does not recover fully and remains low compared to controls. By providing an objective methodology to monitor corneal re-innervation, IVCM adds potentially important findings that may have implications for clinical management and surgical planning.

Bilateral Mooren's ulcer in a child secondary to helminthic infestation of the gastrointestinal tract.

To report an unusual association of bilateral Mooren's ulcer in a child with helminthic infestation of gastrointestinal tract. A 6-year-old female presented with redness, watering and photophobia in left eye for 2 months and in right eye for 2 weeks. BCVA was 20/200 in OD and 20/400 OS. Superior peripheral corneal ulcer of 8 × 2 mm was present in the right eye and 8 × 3 mm perforated limbal corneal ulcer with staphyloma was present in the left eye. Hemogram revealed microcytic hypochromic anemia, eosinophilia and elevated ESR. No organism was isolated on corneal scraping. Stool examination revealed presence of Ancylostoma duodenale. Therapy included fortified topical antibiotics, cycloplegics, lubricants and oral albendazole. Conjunctival recession and crescentic therapeutic penetrating keratoplasty was done in OD and OS respectively. At 18 months follow up, there was no recurrence in any of the eyes. Bilateral Mooren's ulcer may be present with gastrointestinal hookworm infestation. Prompt and appropriate management may provide optimal therapeutic success.

Riboflavin and ultraviolet light a therapy as an adjuvant treatment for medically refractive Acanthamoeba keratitis: report of 3 cases.

PURPOSE: To present the first 3 cases of Acanthamoeba keratitis (AK), unresponsive to medical treatment, that were successfully treated with a novel adjunctive therapy using ultraviolet light A (UVA) and riboflavin (B2). DESIGN: Interventional case series. PARTICIPANTS: Two patients with confirmed AK and 1 patient with presumptive AK, which were all refractive to multidrug conventional therapy. INTERVENTION: Two treatment sessions involving topical application of 0.1% B2 solution to the ocular surface combined with 30 minutes of UVA irradiation focused on the corneal ulcer. MAIN OUTCOME MEASURES: Clinical examination by slit lamp, confocal microscopy, and histopathology, when available. RESULTS: All patients in these series showed a rapid reduction in their symptoms and decreased ulcer size after the first treatment session. The progress of the clinical improvement began to slow after 1 to 3 weeks of the first application and was then renewed after the second application. All ancillary signs of inflammation mostly resolved after the second treatment session. The ulcers in all patients continued to decrease and were closed within 3 to 7 weeks of the first application. Two patients developed dense central corneal scars, and penetrating keratoplasty was performed for visual rehabilitation. Histopathologic examination of the excised tissue revealed no Acanthamoeba organisms. The remaining patient had no symptoms or signs of infection, both clinically and by confocal microscopy, and was left with a semitransparent eccentric scar that did not affect visual acuity. CONCLUSIONS: The adjunctive use of UVA and B2 therapy seems to be a possible alternative for selected cases of medication-resistant AK.

A case of descemet's membrane rupture in a patient affected by Acanthamoeba Keratitis.

OBJECTIVES: We report ultrasound biomicroscopy (UBM) evidence of Descemet's membrane rupture in a patient affected by Acanthamoeba keratitis without corneal perforation. METHODS: A 38-year-old woman who was a habitual wearer of monthly disposable soft contact lens was admitted to our unit for a severe ulcerated corneal abscess. Two days after admission, the patient presented acute stromal hydrops. Ultrasound biomicroscopy examination revealed a Descemet's membrane rupture and an inflammatory reaction in the anterior chamber. Smears with Gram 17 staining and cultural examination revealed the presence of Acanthamoeba. We started specific therapy with propamidine 0.1% and polyhexamethylene biguanide 0.02% eyedrops; we suspended propamidine therapy after 2 weeks form the onset, when the ulcer had recovered, and we continued topical therapy with polyhexamethylene biguanide 0.02% for 6 months. We performed UBM examinations at each control visit during the follow-up that lasted for 18 months. RESULTS: At 1-month's follow-up, the symptoms and corneal alterations had significantly improved, while UBM revealed a spontaneous reattachment of the endothelium-Descemet layer. At 12 months' follow-up, best-corrected visual acuity had improved from hand movements at onset to 20/40, and no sign of intraocular involvement was evidenced. CONCLUSIONS: Acanthamoeba is a ubiquitous protozoan that can affect the cornea, even colonizing the deep layers, causing rupture of the Descemet's membrane. Ultrasound biomicroscopy examination confirmed the severe pathogenicity of this parasite and confirmed that only a prompt diagnosis can limit the damage caused by this affection.

Rose Bengal Photodynamic Antimicrobial Therapy for Patients With Progressive Infectious Keratitis: A Pilot Clinical Study.

PURPOSE: To report clinical outcomes of rose bengal photodynamic antimicrobial therapy (RB-PDAT) as an adjunct treatment for severe, progressive infectious keratitis. DESIGN: Consecutive interventional case series. METHODS: Patients with progressive infectious keratitis unresponsive to standard medical therapy underwent RB-PDAT at the Bascom Palmer Eye Institute from January 2016 through March 2018. RB-PDAT was performed by applying a solution of rose bengal (0.1% or 0.2% RB in balanced salt solution) to the de-epithelialized cornea for 30 minutes, followed by irradiation with a 6 mW/cm2 custom-made green LED source for 15 minutes (5.4 J/cm2). RESULTS: The current study included 18 patients (7 male and 11 female) ranging from 17 to 83 years old. Acanthamoeba was the most frequent microbe (10/17; 59%), followed by Fusarium spp. (4/17; 24%), Pseudomonas aeruginosa (2/17; 12%), and Curvularia spp. (1/17; 6%); 1 patient had no confirmed microbiologic diagnosis. Main clinical risk factor for keratitis included contact lens wear (79%). The average area of epithelial defect prior to first RB-PDAT was 32 ± 27 mm2 and average stromal depth hyperreflectivity measured with anterior segment optical coherence tomography was 269 ± 75 µm. Successful RB-PDAT (avoidance of therapeutic keratoplasty) was achieved in 72% of the cases, with an average time to clinical resolution (decreased pain and inflammation with re-epithelialization and infiltrate resolution) of 46.9 ± 26.4 days after RB-PDAT. Time of follow-up after RB-PDAT was 13.3 ± 5.7 months. CONCLUSION: RB-PDAT can be considered as an adjunct therapy for cases of severe, progressive infectious keratitis before performing a therapeutic keratoplasty.

Clinical profile, risk factors and outcome of medical, surgical and adjunct interventions in patients with Pythiuminsidiosum keratitis.

PURPOSE: To report clinical profile and compare management options for Pythium keratitis. METHOD: Retrospective interventional study of 46 patients diagnosed as Pythium keratitis by PCR DNA sequencing from January 2014 to July 2017. Interventions were categorised into medical management (MM) (topical azithromycin and linezolid with oral azithromycin at presentation), surgery (S) (therapeutic penetrating keratoplasty, TPK), surgical adjunct (SA) (cryotherapy±alcohol with TPK) and medical adjunct (MA) (MM after TPK). RESULTS: Primary treatment included MM (1 eye), SA (3 eyes) and S (42 eyes). Recurrence occurred in 27/43 eyes (MM+S group). Second surgery (S) was required in 11 eyes (TPK-2), with additional procedures (SA) in 10 eyes and evisceration in five eyes. 8/43 eyes received MA after TPK-1. One eye required TPK-3. Recurrence occured in all eyes that received MA (100%) and in 28 of 54 TPKs (51.8%) (TPK 1+2+3) in 42 eyes. Recurrence was noted in 1/14 (7.1%) that underwent SA. CONCLUSION: The currently available and recommended treatment for Pythium keratitis is surgical by means of a TPK and in worse cases evisceration. In our study, MM/MA measures showed no benefit with recurrence or worsening of infection requiring resurgery. Almost 50% of TPKs had a recurrence requiring resurgery. However, adjunctive procedures during TPK appear to have additional benefit with low risk of recurrence and could be included as routine care.

The Acanthamoeba-Fungal Keratitis Study.

PURPOSE: To ascertain the incidence of Acanthamoeba keratitis and the coexistence of Acanthamoeba and fungi in microbial keratitis. DESIGN: Prospective cross-sectional study. METHODS: Patients presenting with stromal keratitis were additionally tested for Acanthamoeba irrespective of the clinical diagnosis. Culture positivity was the gold standard. RESULTS: Of the 401 cases included in the study, 40 were positive for Acanthamoeba (10%); of these 40, 16 were positive for both Acanthamoeba and fungi (4.5% of the study group was Acanthamoeba and fungal keratitis positive); 5 were positive for Acanthamoeba and bacteria; and 2 had triple infection with Acanthamoeba, fungi, and bacteria. Ring infiltrates and stromal edema are frequently associated with Acanthamoeba keratitis, as well as in Acanthamoeba coinfections. Ring infiltrates in particular were more frequently seen in the Acanthamoeba and fungal keratitis group (8/16) and they were often yellowish with hyphate edges (vs ring infiltrates only, which are seen in the patients with Acanthamoeba alone). Only 2 patients were contact lens wearers: however, they presented with history of trauma. CONCLUSIONS: Acanthamoeba coinfections are much more frequent and are not restricted to contact lens users. Anticipating coinfections is necessary for establishing a diagnosis as well as for appropriate and timely therapeutic interventions.

Distinguishing infective versus noninfective keratitis.

For the purpose of this symposium, the term "keratitis" implies suppurative nonviral and viral keratitis. Corneal ulcers have been described in ancient literature. But even today, despite the availability of a wide range of newer antimicrobials and new diagnostic techniques, infective keratitis continues to pose a diagnostic and therapeutic challenge. This article focuses on the key diagnostic clinical features of the most common organisms causing infective keratitis - bacteria, fungi, viruses, nocardia and acanthamoeba - in India. While the clinical features in some cases are fairly straightforward, most cases challenge the clinician. We describe the salient clinical features which can help arrive at a diagnosis to begin appropriate treatment immediately, prior to the laboratory report.

Acanthamoeba keratitis--importance of the early diagnosis.

This is a case report of Acanthamoeba as a causative agent of keratitis at the Department of Ophthalmology, University Hospital Rijeka. Delay in treatment led to an advanced stage of the disease with multiple complications. Initially, presented symptoms were similar to those of herpetic keratitis. In the mean time progression of the disease led to a cloudy cornea with a stromal ring infiltrate, poor vision, elevated intraocular pressure, a mature cataract and finally corneal melt. Corneal scrapings were obtained from a 28 years old female patient, wearing soft contact lenses and with poor lens hygiene. Acanthamoeba cysts were identified by the cytological examination. Culture of the corneal scraping had confirmed Acanthamoeba as the etiological agent. Making the diagnosis of Acanthamoeba is difficult. We presented this case of delayed diagnosis and unfavorable outcome as a reminder that clinical suspicion remains the most important diagnostic tool. Contact lens wears with a new diagnosis of herpes simplex keratitis are in high risk group, especially those with significant pain or poor response to conventional therapy. We also wanted to point out the possibility of an early, prompt and inexpensive diagnosis with the cytological examination.

Bilateral Acanthamoeba ulcer in a user of disposable soft contact lenses: a tragic incident or a consequence of the aggressive policy of soft contact lens trading?

This is the report of a case of bilateral Acanthamoeba keratitis in a 19-year-old woman who bought a pair of disposable soft contact lenses in a boutique. She wore this same pair of lenses for 3 months daily without the appropriate care. This led to bilateral corneal transplantation with cataract extraction and also trabeculectomy in the right eye. When last seen, both grafts were crystal clear but the visual acuities were far from satisfactory. She also had bilateral secondary glaucoma, barely controlled by topical medication. Actually, the physical features and the wearing time characteristics of the disposable soft contact lenses created unprecedented difficulties to the medical surveillance of their wearers. Without the right assistance they tend to become careless regarding routine cleaning. They also feel free to buy less expensive lenses, to use saline instead of lens solutions, to violate the limits of wearing time and to extend the use over the sleeping period. Additionally, the aggressive marketing and the wide distribution of these lenses increase the chances that economically or educationally unprepared people will acquire them. The question that remains is: Is the present case an accidental event or an example of what is likely to happen in the future if the indiscriminate selling of disposable soft contact lenses continues to evolve?

Identifying Corneal Infections in Formalin-Fixed Specimens Using Next Generation Sequencing.

Purpose: We test the ability of next-generation sequencing, combined with computational analysis, to identify a range of organisms causing infectious keratitis. Methods: This retrospective study evaluated 16 cases of infectious keratitis and four control corneas in formalin-fixed tissues from the pathology laboratory. Infectious cases also were analyzed in the microbiology laboratory using culture, polymerase chain reaction, and direct staining. Classified sequence reads were analyzed with two different metagenomics classification engines, Kraken and Centrifuge, and visualized using the Pavian software tool. Results: Sequencing generated 20 to 46 million reads per sample. On average, 96% of the reads were classified as human, 0.3% corresponded to known vectors or contaminant sequences, 1.7% represented microbial sequences, and 2.4% could not be classified. The two computational strategies successfully identified the fungal, bacterial, and amoebal pathogens in most patients, including all four bacterial and mycobacterial cases, five of six fungal cases, three of three Acanthamoeba cases, and one of three herpetic keratitis cases. In several cases, additional potential pathogens also were identified. In one case with cytomegalovirus identified by Kraken and Centrifuge, the virus was confirmed by direct testing, while two where Staphylococcus aureus or cytomegalovirus were identified by Centrifuge but not Kraken could not be confirmed. Confirmation was not attempted for an additional three potential pathogens identified by Kraken and 11 identified by Centrifuge. Conclusions: Next generation sequencing combined with computational analysis can identify a wide range of pathogens in formalin-fixed corneal specimens, with potential applications in clinical diagnostics and research.

Hookworm infestation as a risk factor for Mooren's ulcer in South India.

OBJECTIVE: To investigate the association between Mooren's ulcer and intestinal hookworm infestation in South India. DESIGN: Prospective observational case-control study. PARTICIPANTS: Fifteen patients with Mooren's ulcer and 30 age- and gender-matched controls seen at Aravind Eye Hospital. METHODS: Stool samples from the Mooren's ulcer patients and controls were collected and analyzed for presence of hookworm infestation. MAIN OUTCOME MEASURE: Prevalence of hookworm infestation in Mooren's ulcer patients and controls. RESULTS: There was a statistically significant correlation between intestinal hookworm infestation and the occurrence of Mooren's ulcer (P = 0.009). Retrospective exploratory subgroup analyses suggested that the correlation between intestinal hookworm infestation and the occurrence of Mooren's ulcer in men (P<0.0001) was stronger than the correlation in women, with no statistically significant difference being observed in the prevalence of hookworm infestation between women with Mooren's ulcer and female control subjects (P>0.99). Similarly, when both the Mooren's ulcer and the control subject groups were analyzed retrospectively by age > 50 years or age < 50, subjects with an age over 50 demonstrated a stronger correlation between hookworm infestation and Mooren's ulcer than controls (P = 0.017), whereas there was no statistically significant difference in the prevalence of hookworm infection between Mooren's ulcer subjects and control subjects < or = 50 (P = 0.31). CONCLUSION: Intestinal hookworm infestation appears to be associated with the development of Mooren's ulcer in South India. Although the power of our retrospective exploratory subgroup analyses was limited by multiple testing and small sample sizes, these data suggest further that the correlation between intestinal hookworm infestation and the development of Mooren's ulcer may be greatest in male patients with more advanced age.

The clinical diagnosis of microbial keratitis.

PURPOSE: To evaluate the ability of ophthalmologists to predict the laboratory results of presumed microbial keratitis and to explore which findings may influence diagnostic prognostication. DESIGN: Prospective, cross-sectional study. METHODS: Fifteen ophthalmologists completed study forms at the initial presentation of patients with presumed microbial keratitis. After predicting the category of microbial recovery, clinicians submitted corneal scrapings for masked laboratory processing. The relative effects of ocular inflammatory signs on correct microbial diagnosis were explored with Poisson regression. RESULTS: Clinical examiners correctly predicted the presence or absence of microbial recovery in 79 (76%) of 104 ulcerative keratitis cases and successfully distinguished among bacterial, fungal, and amebic keratitis for 54 (73%) of 74 culture-positive infections, although only 31 (42%) were subcategorized properly. The positive predictive value of clinical diagnosis was 65% (95% confidence interval [CI], 43% to 84%) for 20 eyes with Pseudomonas keratitis cases, 48% (95% CI, 32% to 63%) for 38 other bacterial keratitis, 45% (95% CI, 17% to 77%) for 13 fungal keratitis, and 89% (95% CI, 52% to 100%) for nine Acanthamoeba keratitis cases. The recognition of Pseudomonas keratitis significantly improved by the occurrence of a larger infiltrate (P = .02), and correctly predicting Acanthamoeba keratitis was enhanced by observing a ring infiltrate (P < .001). Antimicrobial use before referral significantly attenuated clinical diagnosis (P = .03) and hampered microbial recovery (P = .004). CONCLUSIONS: Established Pseudomonas keratitis and Acanthamoeba keratitis can be suspected before laboratory confirmation, but overlapping inflammatory features and recent empiric antimicrobial treatment limits etiologic recognition of most microbial corneal infections.

Microbial keratitis in South India: influence of risk factors, climate, and geographical variation.

PURPOSE: To determine the influence of risk factors, climate, and geographical variation on the microbial keratitis in South India. METHODS: A retrospective analysis of all clinically diagnosed infective keratitis presenting between September 1999 and August 2002 was performed. A standardised form was filled out for each patient, documenting sociodemographic features and information pertaining to risk factors. Corneal scrapes were collected and subjected to culture and microscopy. RESULTS: A total of 3,183 consecutive patients with infective keratitis were evaluated, of which 1,043 (32.77%) were found to be of bacterial aetiology, 1,095 (34.4%) were fungal, 33 (1.04%) were Acanthamoeba, 76 (2.39%) were both fungal and bacterial, and the remaining 936 (29.41%) were found to be culture negative. The predominant bacterial and fungal pathogens isolated were Streptococcus pneumoniae (35.95%) and Fusarium spp. (41.92%), respectively. Most of the patients (66.84%) with fungal keratitis were between 21 and 50 years old, and 60.21% of the patients with bacterial keratitis were older than 50 (p < 0.0001) (95% CI: 5.19-7.19). A majority of patients (64.75%) with fungal keratitis were agricultural workers (p < 0.0001) [odds ratio (OR): 1.4; 95% CI: 1.19-1.61], whereas bacterial keratitis occurred more commonly (57.62%) in nonagricultural workers (p < 0.0001) (OR: 2.88; 95% CI: 2.47-3.36). Corneal injury was identified in 2,256 (70.88%) patients, and it accounted for 92.15% in fungal keratitis (p < 0.0001) (OR: 7.7; 95% CI: 6.12-9.85) and 100% in Acanthamoeba keratitis. Injuries due to vegetative matter (61.28%) were identified as a significant cause for fungal keratitis (p < 0.0001) (OR: 23.6; 95% CI: 19.07-29.3) and due to mud (84.85%) for Acanthamoeba keratitis (p < 0.0001) (OR: 26.01; 95% CI: 3.3-6.7). Coexisting ocular diseases predisposing to bacterial keratitis accounted for 68.17% (p < 0.0001) (OR: 33.99; 95% CI: 27.37-42.21). The incidence of fungal keratitis was higher between June and September, and bacterial keratitis was less during this period. CONCLUSION: The risk of agricultural predominance and vegetative corneal injury in fungal keratitis and associated ocular diseases in bacterial keratitis increase susceptibility to corneal infection. A hot, windy climate makes fungal keratitis more frequent in tropical zones, whereas bacterial keratitis is independent of seasonal variation and frequent in temperate zones. Microbial pathogens show geographical variation in their prevalence. Thus, the spectrum of microbial keratitis varies with geographical location influenced by the local climate and occupational risk factors.

Intraocular minocycline for the treatment of ocular pythiosis.

PURPOSE: A case of ocular pythiosis successfully treated with surgery and intraocular and oral minocycline is reported. SUMMARY: A 30-year-old man who wore corrective contact lenses traveled to Brazil and Colombia where he swam in salt and fresh waters while wearing contact lenses. He sought treatment at an emergency department after 2 weeks of suffering with a painful corneal ulcer, redness, and loss of vision in his right eye that had been treated at other centers with ophthalmic moxifloxacin for 10 days and with fortified topical antibiotics (amikacin and vancomycin) for 2 days. Examination using a slit lamp revealed a deep central corneal ulcer with surrounding white infiltrate, endothelial plaque, and hypopyon. Due to infection severity, the patient was admitted and received empirical antibiotic therapy and i.v. and topical antifungals. During the first corneal transplantation, the patient's original infection relapsed and was treated with voriconazole and liposomal amphotericin B intraocular injections. A subsequent infection developed, and a second keratoplasty was performed. One month after hospital admission, the patient was diagnosed with ocular pythiosis and therapy with oral minocycline was initiated. After severe infection relapse in the anterior chamber, the patient underwent a third penetrating keratoplasty, where minocycline intraocular injection was administered. After this intervention, complete infection control was achieved, and the patient was discharged 45 days after admission with oral minocycline and 1% cyclosporine and 0.3% ofloxacin eye drops. CONCLUSION: A patient with ocular pythiosis was successfully treated with penetrating keratoplasty and 2 months of treatment with intracameral and oral minocycline.

Diagnosis and Treatment of Pythium Insidiosum Corneal Ulcer in a Chinese Child: A Case Report and Literature Review.

BACKGROUND Pythium insidiosum keratitis is a rare but sight-threatening disease with a high morbidity rate. It can be misdiagnosed as fungal keratitis in clinic settings. We report a case of severe Pythium insidiosum keratitis in a Chinese child, treated with combined approaches. CASE REPORT A 7-year-old boy from Hainan province in the south of China developed a suppurative corneal ulcer after being in a forest. A mass of hyphae was detected by confocal imaging in vivo, fungal smear test, and histochemical examination. Treatment with Natamycin, fluconazole, and Voriconazole for 1 month was unsuccessful, and a penetrating keratoplasty with anterior vitrectomy was performed. The infection reappeared 1 day after surgery, immediately after which anterior chamber irrigation with 0.02% Fluconazole and amphotericin B solution was performed. Finally, the globe was saved and there was no further recurrent infection. A cultured mycelial organism, which was hard to identify by biomorphology, was confirmed by PCR to be Pythium insidiosum. The zoospores were observed in water environments. The imaging characteristics of P. insidiosum in confocal microscopy are described herein. CONCLUSIONS This is the first case of Pythium insidiosum keratitis reported in China. It can be misdiagnosed as fungal keratitis in the clinic. Improving the awareness of clinicians, promoting early diagnosis, and a multidisciplinary approach, especially early surgery, improve the prognosis.

Rare Case of Polymicrobial Keratitis With Balantidium coli.

PURPOSE: To report a rare case of polymicrobial keratitis due to Balantidium coli and gram-negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumoniae, in a soft contact lens (CL) wearer. METHODS: We report a case of CL-related keratitis due to B. coli, P. aeruginosa, and K. pneumoniae. RESULTS: The culture of the corneal scrapings, the CL cleaning solution, and the CL revealed the growth of a rare ciliated parasite, B. coli, along with gram-negative bacteria, namely, P. aeruginosa and K. pneumoniae. The patient was successfully treated with topical broad-spectrum antibiotics and intravenous metronidazole. CONCLUSIONS: Polymicrobial keratitis has seldom been reported with B. coli as the causative agent. CL wear can be a risk factor for this infection. Treatment with topical antibiotics may not suffice, and the intravenous route of antiprotozoal drugs may be a useful adjunct. Increasing awareness, early diagnosis, and treatment may improve the final visual outcome.