Effect of topical bovine colostrum in wound healing of corneal surface after acute ocular alkali burn in mice.

The purpose of this study was to evaluate the effect of bovine colostrum (BC) in the regeneration of corneal epithelial cells on an ocular alkali burn model. Twenty-four C57BL/6 mice were categorized into two gender/age-matched groups for treatment. Two days after inducing a corneal alkali burn in all left eyes with 4 µl of sodium hydroxide 0.15 mol/l, both eyes of group 1 were treated with BC 4 times per day, and both eyes of group 2 were treated with isotonic saline solution (SS). The epithelial defect was photographed and measured by fluorescein staining on days two, four, seven, and ten. Ocular burn damage was assessed with a pre-established classification in clock hours from the limbus. After 10 days both eyes were processed, half of the group's corneas were assessed histopathologically, and the other half was used for pro/anti-inflammatory cytokine quantification using ELISA. BC treated (Group 1) corneas revealed significantly improved fluorescein staining score for limbal involvement when compared to SS treated (Group 2) corneas at days 4 (p = 0.013), 7 (p < 0.001), and 10 (p < 0.001), respectively. No differences were noted in limbal involvement at day 2 between the two groups (p > 0.99). The overall change (difference in slope) in fluorescein staining for limbal involvement between days 2 and 10 was -0.1669 (p = 0.006). Histologic examinations and cytokine measurements of group 2 demonstrated a strong inflammatory component compared to group 1. Our data indicates that topical application of BC facilitates corneal re-epithelialization and wound healing by suppressing the inflammatory process in an ocular alkali burn model.

Outcomes of different concentrations of human amniotic fluid in a keratoconjunctivitis sicca-induced mouse model.

To compare the effects of different concentrations of topical human amniotic fluid (HAF) in a mouse model of dry eye, forty C57BL/6 mice were divided into 4 treatment groups: 20 % HAF, 50 % HAF, 100 % HAF, and isotonic salt solution (control). Dry eye was induced by an injection of botulinum toxin B into the lacrimal gland. Tear production, ocular surface fluorescein staining, and blink rate were evaluated in each mouse at 5 time points during a 4-week period. Goblet cell density was assessed in stained histological sections. Regarding tear production, 20, 50, and 100 % HAF groups were all different from the control group (P < 0.001) at week 1. However, there were no statistically significant differences between the 20, 50, and 100 % HAF groups. At week 2, 20, 50, and 100 % HAF groups had significant improvement in staining score and were significantly different from the control group (P = 0.047, P = 0.005, and P = 0.001, respectively). No difference in spontaneous blink rate was observed between groups, at any time point. Goblet cell density was significantly decreased in the control group compared to the HAF treatment groups. All tested concentrations of topical HAF were effective and superior than the control in this keratoconjunctivitis sicca-induced mouse model. Further studies are needed to evaluate the effects of HAF on the human ocular surface.

Characteristics of Endophthalmitis after Cataract Surgery in the United States Medicare Population.

PURPOSE: Endophthalmitis is a rare but sight-threatening infection after cataract surgery. Roughly one third of eyes remain blind after treatment. We report United States population-based data on microbiological investigations and treatment patterns plus risk factors for poor outcomes. DESIGN: Retrospective cohort study. PARTICIPANTS: Medicare beneficiaries from 5 states in whom endophthalmitis developed within 6 weeks after cataract surgery in 2003 and 2004. METHODS: We identified endophthalmitis cases occurring after cataract surgery using Medicare billing claims. We contacted treating physicians and requested they complete a questionnaire on clinical and microbiological data and submit relevant medical records. Two independent observers reviewed materials to confirm that cases met a standardized definition. MAIN OUTCOME MEASURES: Positive culture results, vitrectomy status, microbiology spectrum, and final visual acuity. RESULTS: In total, 615 cases met our case definition. Initial visual acuity was counting fingers or worse for 72%. Among 502 cases with known culture results, 291 (58%) had culture positive results. Twelve percent had positive results for streptococci. More than 99% of cases were treated with intravitreal vancomycin. Vitrectomy was performed in 279 cases (45%), including 201 cases with initial acuity better than light perception. Rates of vitrectomy varied across states, with California having the highest rate and Michigan having the lowest (56% and 19% of cases, respectively). Overall, 43% of individuals achieved visual acuity of 20/40 or better. Poor initial acuity (adjusted odds ratio [OR], 1.08; 95% confidence interval [CI], 1.04-1.12 per 0.10 logarithm of the minimum angle of resolution units), older age at diagnosis (OR, 1.22; 95% CI, 1.03-1.45 per 5-year increase), and more virulent organisms were important predictors of poor final visual acuity. Cases with streptococci infection were 10 times more likely to have poor final acuity than coagulase-negative staphylococci cases (adjusted OR, 11.28; 95% CI, 3.63-35.03). Vitrectomy was not predictive of final visual acuity (adjusted OR, 1.26; 95% CI, 0.78-2.04). CONCLUSIONS: Population-based data on the microbiology of acute postoperative endophthalmitis in the United States after cataract surgery are consistent with prior reports. Vitrectomy usage is higher than that recommended from the Endophthalmitis Vitrectomy Study, with no evidence of increased benefit.

Bactericidal Efficacy of High Irradiance Ultraviolet A Photoactivation of Riboflavin Versus Standard Corneal Cross-Linking Protocol In Vitro.

PURPOSE: The purpose of this study was to compare the efficacy of high ultraviolet A (UVA) irradiance photoactivation of riboflavin (vitamin B2) versus the standard corneal cross-linking protocol on bacterial viability. METHODS: Methicillin-sensitive Staphylococcus aureus (MSSA) Newman strain and methicillin-resistant multidrug-resistant S. aureus (MDR-MRSA) USA300, CA409, CA127, GA656, and NY315 strains were exposed to a UVA energy dose of 5.4 to 6 J/cm 2 by 2 high irradiance regimens: A) 30 mW/cm 2 for 3 minutes and B) 10 mW/cm 2 for 10 minutes with B2 0.1%. Control groups included B2/UVA alone, CA409 exposed to standard B2 0.1% + UVA (3 mW/cm 2 for 30 minutes), and an untreated sample. Cell viability was assessed. Triplicate values were obtained. The Mann-Whitney test and Student t test were used for statistical analysis. RESULTS: There was no difference comparing the median bacterial load (log CFU/mL) of the untreated samples versus regimen A: Newman P = 0.7, CA409 P = 0.3, USA300 P = 0.5, CA127 P = 0.6, GA656 P = 0.1, and NY315 P = 0.2 ( P ≥ 0.1); and B: Newman P = 0.1, CA409 P = 0.3, USA300 P = 0.4, CA127 P = 0.6, GA656 P = 0.1, and NY315 P = 0.3 ( P ≥ 0.1). Standard regimen killed 100% of CA409. CONCLUSIONS: Photoactivation of B2 by high UVA irradiance does not seem to be effective for bacterial eradication in this study.

Pseudo second anterior lens capsule during post-vitrectomy cataract surgery: A case report.

Purpose: To report the unexpected finding of a membrane resembling a second anterior lens capsule during cataract surgery after previous pars plana vitrectomy (PPV) with silicone oil tamponade for retinal detachment. Observations: A 26-year-old male with a history of two retinal detachment repairs of the right eye over a 5-month period, presented with decreased vision. The first retinal detachment repair was performed with a 23-gauge PPV and the second with a 25-gauge PPV, scleral buckle and placement of silicone oil. Additional ocular history includes bilateral megalocornea, high myopia, and temporal lens coloboma. Upon presentation, slit lamp exam showed migration of silicone oil to the anterior chamber and a nuclear cataract. A decision was made to perform combined silicone oil removal and cataract extraction with intraocular lens (IOL) implant of the right eye. After capsulorrhexis, hydrodissection of the lens was not completed successfully since the presence of a membrane was detected. This membrane was cut, achieving partial completion of the second capsulorrhexis, which was further advanced using a forceps following the contour of the first capsulorrhexis. The cataract was removed without further difficulty and the IOL was placed into the capsular bag with good centration. The membrane was submitted to pathology, and upon microscopic examination was found to represent fibrocellular tissue with some cells expressing PAX8 and cytokeratin AE1/AE3. Conclusions and importance: This case reports the unusual finding of a membrane that behaved as a second anterior lens capsule intraoperatively and that expressed novel pathology markers. These findings may better prepare ophthalmologists for similar pathologies they may encounter during capsulorrhexis.

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.

Analysis of protein composition of rabbit aqueous humor following two different cataract surgery incision procedures using 2-DE and LC-MS/MS.

BACKGROUND: The aqueous humor (AH), a liquid of the anterior and posterior chamber of the eye, comprises many proteins with various roles and important biological functions. Many of these proteins have not been identified yet and their functions in AH are still unknown. Recently, our laboratory published the protein database of AH obtained from healthy rabbits which expanded known protein identifications by 65%. Our present study extends our previous work and analyses AH following two types of cataract surgery incision procedures (clear corneal and limbal incisions) by using two dimensional gel electrophoresis (2-DE) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Although both incision protocols are commonly used during cataract surgeries, the difference in protein composition and their release into AH following each surgery has never been systematically compared and remains unclear. The first step, which is the focus of this work, is to assess the scale of the protein change, at which time does maximum release occurs and when possible, to identify protein changes. RESULTS: Samples of AH obtained prior to surgery and at different time points (0.5, 2, 12, 24 and 48 hours) following surgery (n = 3/protocol) underwent protein concentration determination, 2-DE and LC-MS/MS. There was a large (9.7 to 31.2 mg/mL) and rapid (~0.5 hour) influx of proteins into AH following either incision with a return to baseline quantities after 12 hours and 24 hours for clear corneal and limbal incision, respectively. We identified 80 non-redundant proteins, and compared to our previous study on healthy AH, 67.5% of proteins were found to be surgery-specific. In addition, 51% of those proteins have been found either in clear corneal (20%) or limbal incision (31%) samples. CONCLUSIONS: Our results imply that a mechanism of protein release into AH after surgery is a global response to the surgery rather than increase in amount of protective proteins found in healthy AH and a mechanism of protein release for each type of incision procedure could be different. Although the total protein concentration was increased (at 0.5 and 2 hour time points and between types of surgery) many of 2-DE protein spots were similar based on 2-DE and MS analyses, and only a small number of protein spots changed with either the time points or surgical conditions (0.4 -1.9%). This suggests that the high protein content is due to an increase in the concentration of the same proteins with only a few unique proteins being altered per time point and with the different surgery type. This is the first report on the comparison of AH protein composition following two different cataract surgery procedures and it establishes the basis for better understanding of protein release into AH during events such as cataract surgery or other possible intervention to the eyes.

Infection with persister forms of Staphylococcus aureus causes a persistent skin infection with more severe lesions in mice: failure to clear the infection by the current standard of care treatment.

Staphylococcus aureus can cause persistent infections and is known to develop persister cells in vitro. However, the in vivo significance of in vitro persisters in general is largely unclear. Here, we evaluated S. aureus stationary phase cultures and biofilm bacteria enriched in persister bacteria in comparison with actively growing log phase bacteria in terms of their ability to cause disease in a mouse skin infection model. We found that mice infected with the stationary phase and biofilm bacteria, which were enriched with persisters, produced more pronounced skin lesions that took longer to heal, and had more severe skin pathology and higher bacterial load than mice infected with log phase bacteria. Using our persistent infection mouse model, we showed that the clinically recommended treatment for recurrent S. aureus skin infection, doxycycline + rifampin, was not effective in eradicating the bacteria in mice. Analogous findings were observed in a Caenorhabditis elegans model, where stationary phase S. aureus caused greater virulence or mortality than log phase bacteria as early as two days post-infection. Our findings associate in vitro persisters and biofilm bacteria with more persistent and more severe infections and emphasize the importance of quality or metabolic status of the inoculum bacteria (persister bacteria versus growing bacteria) not just the number of bacteria in causing disease. The persistent infection mouse model we developed with persister inocula should have implications for understanding the process of disease establishment and pathogenesis, for developing persistent infection animal models, and for developing more effective treatments for chronic persistent infections in general.

Dynamics of small-incision clear cornea wounds after phacoemulsification surgery using optical coherence tomography in the early postoperative period.

PURPOSE: To evaluate wound dynamics in the immediate postoperative period after phacoemulsification surgery using a small-incision clear cornea approach. METHODS: Eight patients underwent standard postoperative evaluation 24 hours after uneventful phacoemulsification surgery performed through a temporal or nasal clear corneal incision. Additional screening was performed with non-contact optical coherence tomography (Visante Anterior Segment OCT) to examine the corneal wounds. RESULTS: One patient showed partial spontaneous gaping in different areas of the incision, undetected at slit-lamp evaluation. This patient presented with a mild senile bilateral ptosis. Another patient showed localized gaping of the internal aspect of the corneal wound. Both patients had intraocular pressures of 10 mmHg, which were the lowest pressures recorded in the group. Four other incisions showed some degree of localized Descemet's membrane detachment in the vicinity of the wound, also undetected by slit-lamp evaluation. CONCLUSIONS: Small-incision clear cornea wounds may gape in the immediate postoperative period. If the gape occurs along the entire length of the wound, it may lead to inadvertent bacterial access into the anterior chamber. Optical coherence tomography also indicates that localized detachment of Descemet's membrane may be more common than observed with slit-lamp microscopy.

Analysis of clear corneal incision integrity in an ex vivo model.

PURPOSE: To determine the most favorable sutureless incision configuration to minimize extraocular fluid inflow after cataract surgery. SETTING: The Wilmer Eye Institute, Baltimore, Maryland, USA. METHODS: Five fresh human eyes were used in the study. Two 27-gauge needles connected to a saline solution bag and a digital manometer were inserted through the limbus 180 degrees from each other. Intraocular pressure (IOP) was maintained at 15 to 20 mm Hg. Three incisions were performed in different quadrants of each cornea: uniplanar 1.0 mm and 3.0 mm tunnel lengths and 2-step 3.0 mm tunnel length. India ink was applied to the incision site, and IOP fluctuation was induced by applying pressure to the limbal area of the opposite quadrant using an ophthalmodynamometer. Imaging was performed before and after pressure application. RESULTS: The linear distance of India ink inflow after pressure application was higher than the prepressure measurements in the 1.0 mm and 3.0 mm incision groups (P = .039 and P = .023, respectively). The maximum mean of inflow after pressure application was not higher than the prepressure measurement in the 2-step incision group (P = .105). The total ink area measured before and after pressure applications in the incisions of the 3 groups was not significantly different (P = .285). CONCLUSIONS: Intraocular pressure fluctuations may promote entry of bacteria-size particles into the eye when 1.0 mm and 3.0 mm single-plane incisions are performed. Stepped incisions seem to be more resistant to inflow in the presence of IOP fluctuation.