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Pancreatic cancer is characterized by extensive resistance to conventional therapies, making clinical management a challenge. Here we map the epigenetic dependencies of cancer stem cells, cells that preferentially evade therapy and drive progression, and identify SWI/SNF complex member SMARCD3 as a regulator of pancreatic cancer cells. Although SWI/SNF subunits often act as tumor suppressors, we show that SMARCD3 is amplified in cancer, enriched in pancreatic cancer stem cells and upregulated in the human disease. Diverse genetic mouse models of pancreatic cancer and stage-specific Smarcd3 deletion reveal that Smarcd3 loss preferentially impacts established tumors, improving survival especially in context of chemotherapy. Mechanistically, SMARCD3 acts with FOXA1 to control lipid and fatty acid metabolism, programs associated with therapy resistance and poor prognosis in cancer. These data identify SMARCD3 as an epigenetic modulator responsible for establishing the metabolic landscape in aggressive pancreatic cancer cells and a potential target for new therapies., (© 2023. The Author(s).)

In Australia and Denmark, women aged 50-70 years are more likely than younger women to consume alcohol at levels that exceed national low risk drinking guidelines. To explore and possibly help explain this sociocultural shift in patterns of alcohol use, this research investigated the social construction of alcohol use amongst 49 women (25 in Northern Denmark, 24 in Western Australia) aged 50-69 years. The women viewed drinking as normal and acceptable. While some women reported reducing their drinking due to health concerns, others neutralised alcohol-related health risks through compensatory behaviours including exercise. Such constructions arguably serve to sustain at-risk drinking amongst some women. Our research highlights that interventions to minimise alcohol-related health risks amongst middle-aged and young-old women should acknowledge that women's social construction of their drinking practices may prioritise subjective experiences of "being in control" while drinking, over biomedical understandings of the health impacts of alcohol., (© 2019 Foundation for the Sociology of Health & Illness.)

Exercise, spending time in nature and feeling part of a supportive community all contribute to better physical and mental health and to healthy ageing. This focused ethnography investigates how participation in self-organised ocean swimming groups contributes to healthy ageing amongst older men and women in the Australian coastal city of Perth. It explores the ways marine life, personal experiences and social connectedness mediate their group use of public blue space, and highlights that group membership promotes participants' enhanced health and wellbeing, and supports development of self-efficacy and resilience. These findings suggest that more inclusive access to ocean swimming and other forms of active or adventure-based leisure activities should be advocated from a public health perspective., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Venous thromboembolism (VTE) is a life-threatening complication of anti-neutrophil cytoplasmic autoantibody (ANCA) vasculitis whose mechanism remains incompletely elucidated. We tested the hypothesis that elevated microparticle tissue factor activity (MPTFa) or anti-plasminogen antibodies (anti-Plg) may identify patients at risk for VTE., Methods: In this prospective study, patients were enrolled during active disease and followed longitudinally. Twelve patients who experienced a VTE (VTE pos ) were compared with patients without VTE (VTE neg , n  = 29) and healthy controls (HC, n  = 70). MPTFa, anti-Plg, interleukin-6, high-sensitivity C-reactive protein (hs-CRP), D-dimer, serum creatinine, and serum albumin were assessed. Fisher's exact tests and Wilcoxon tests compared categorical and continuous variables, respectively. Cox regression for time to VTE or last follow-up was performed., Results: VTE pos patients had higher MPTFa (peak median = 14.0, interquartile range = 4.3-36.6) than HC (0, 0-3.5) and VTE neg patients (0, 0-1.4). In time-to-event analysis, MPTFa was associated with VTE when measured during both active disease (hazard ratio [HR]; 95% confidence interval [CI]: 1.04; 1.01-1.08) and remission (1.4; 1.11-1.77). Anti-Plg during remission was also associated with VTE (1.17; 1.03-1.33). Each g/dl decrease of serum albumin was associated with a 4-fold increase in VTE risk (4.4; 1.5-12.9). Adjusting for estimated glomerular filtration rate (eGFR), anti-Plg during remission remained significantly associated with VTE., Conclusion: Elevated MPTFa and increased anti-Plg in remission are strong indicators of VTE independent of renal function. Association of anti-Plg during remission with VTE implies hypercoagulability even during disease quiescence. Hypoalbuminemia strongly portends VTE risk, which is a novel finding in ANCA vasculitis. A thrombotic signature would allow improved management of patients to minimize VTE risk and complications of anticoagulation., (© 2019 International Society of Nephrology. Published by Elsevier Inc.)

Significance: Determining risk factors for posterior capsule opacification will allow for further interventions to reduce the risk of development and thus additional procedures., Purpose: The purpose of this study was to investigate risk factors associated with development of clinically significant posterior capsule opacification requiring yttrium aluminum garnet (YAG) capsulotomy., Methods: Medical records of patients (≥18 years) who underwent cataract surgery between January 1, 2011, and March 31, 2014, at Kresge Eye Institute were reviewed. Three hundred eyes requiring YAG capsulotomy up to 3 years after cataract surgery were included in the YAG capsulotomy group. Three hundred eyes not requiring YAG capsulotomy up to 3 years after cataract surgery were selected via age-matched simple randomization (control group)., Results: The YAG capsulotomy group included patients with younger age (65.8 ± 11.3 vs. 70.1 ± 10.6 years, P < .001), more men (42.67 vs. 34.67%, P = .04), fewer patients with hypertension (73.00 vs. 83.00%, P < .001), and more patients with hydrophilic intraocular lenses (74.67 vs. 47.00%, P < .001). Logistic regression analysis demonstrated a negative association between YAG capsulotomy and age (coefficient, -0.04; 95% confidence interval [CI], 0.95 to 0.98; P < .001) and hydrophobic intraocular lenses (coefficient, -1.50; 95% CI, 0.15 to 0.33; P < .001), and a positive association with presence of glaucoma (coefficient, 0.88; 95% CI, 1.39 to 4.17; P = .002). Elapsed time to YAG capsulotomy was sooner in patients with a history of uveitis (95% CI, 5.10 to 9.70 months; P = .02) and insertion of hydrophilic intraocular lenses (95% CI, 18.67 to 21.57 months; P < .001)., Conclusions: Results of this study suggest that development of visually significant posterior capsule opacification is associated with younger age, glaucoma, and hydrophilic intraocular lenses, and it occurs earlier among those with hydrophilic intraocular lenses and a history of uveitis.

The iconic helical structure of DNA is stabilized by the solvation environment, where a change in the hydration state can lead to dramatic changes to the DNA structure. X-ray diffraction experiments at cryogenic temperatures have shown crystallographic water molecules in the minor groove of DNA, which has led to the notion of a spine of hydration of DNA. Here, chiral nonlinear vibrational spectroscopy of two DNA sequences shows that not only do such structural water molecules exist in solution at ambient conditions but that they form a chiral superstructure: a chiral spine of hydration. This is the first observation of a chiral water superstructure templated by a biomolecule. While the biological relevance of a chiral spine of hydration is unknown, the method provides a direct way to interrogate the properties of the hydration environment of DNA and water in biological settings without the use of labels.

Objectives: This research aimed to identify older Australian drinkers' knowledge about Australian Alcohol Guidelines and their beliefs about the risks and benefits of alcohol; their recall of alcohol-related issues being raised with them by their community pharmacist and General Practitioner (GP); and their receptiveness to alcohol-related information being provided by either health professional., Methods: This research was conducted in Perth, Western Australia. Flyers calling for participants were placed in local health and service centres, and advertisements were placed in local media. Participants who met eligibility requirements were posted a survey pack (n = 190) including an information letter, consent form, quantitative survey, and return addressed, postage paid envelope. 188 people aged over 60 years returned completed questionnaires., Key Findings: Women were more familiar with national alcohol guidelines, and were more conservative about the potential health benefits of alcohol. While 90% of participants were receptive to their GP asking about their alcohol use, only 30% of men and 20% of women recalled their GP raising this issue with them in the prior 12 months. Of these, high-risk drinkers were six times more likely than low-risk drinkers to have been asked by their GP. Likewise, 50% of men and 65% of women were receptive to having alcohol-related health conversations with their community pharmacist, but less than 4% recalled their pharmacist raising this issue. Participants were most receptive to receiving information about alcohol-medication interactions., Conclusions: This research highlights that prescribing and dispensing medication represents the ideal opportunity for health professionals to deliver alcohol-related information to older people., (© 2016 Royal Pharmaceutical Society.)

Chiral sum frequency generation spectroscopy (SFG) is of great interest for studying biological systems, among others. Whereas the chiral response in circular dichroism is about 0.1% of the achiral response, the chiral SFG response can be the same order of magnitude as the achiral SFG signal. However, chiral SFG is limited by the attainable signal-to-noise of the weak nonlinear signals and therefore extremely sensitive to proper alignment. We present a robust method for chiral SFG and demonstrate the use on solid-air surfaces with achiral and chiral molecules. We simultaneously measure two orthogonal polarizations-either the interference chiral SFG (±45° polarized) or the pure chiral and achiral SFG-using a waveplate and beam displacer. Both optics are placed in the detection arm and can be easily incorporated into any SFG setup. Furthermore, we employ self-referencing to calibrate alignment for each sample individually using a polarizer in the detection arm. These methods greatly increase the reliability and quality of chiral SFG measurements.

Introduction: The safety, cost efficacy, and time-to-treatment benefit of air transport of stroke patients have been acknowledged. We describe stroke patients transported to our facility by helicopter emergency medical services (HEMS) from a large rural area and compare 2 consecutive 3-year periods., Methods: A retrospective chart review was conducted of all patients transferred by HEMS to our facility over 6 years. Data collected included patient demographics, pretransport imaging interpretation, final diagnosis, treatment, and outcomes. Trends between period 1 (January 1, 2003'December 31, 2005) and period 2 (January 1, 2006'December 31, 2008) were examined., Results: A total of 347 acute stroke patients were transported by HEMS to our facility. The final diagnosis was intracerebral hemorrhage in 44%, subarachnoid hemorrhage in 24%, subdural hematoma in 14%, ischemic stroke or transient ischemic attack in 9%, and a nonstroke diagnosis in 7% of patients. Conventional cerebral angiography was performed in 28% of patients, and neurosurgical intervention, hematoma evacuation, or aneurysm clipping was performed in 32%. A final diagnosis of ischemic stroke or transient ischemic attack increased 3 times (4% vs. 12%, P < .05) from period 1 to 2. There was also a significant increase in the number of patients receiving intravenous tissue plasminogen activator before transport (0% vs. 3%, P < .01)., Conclusions: The majority of our patients transported by HEMS for the management of acute stroke undergo urgent specialized diagnostics or interventions. This supports the role of interhospital HEMS transport in extending access to care in rural communities., (Copyright © 2013 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.)

Context: With one exception, a case report of amantadine-induced corneal toxicity has described reversible corneal edema., Objective: To report a patient with unrecognized amantadine-induced corneal edema., Design: Patient with schizophrenia and tardive dyskinesia developed bilateral corneal edema while receiving chronic amantadine hydrochloride. Both eyes underwent successful phakic Descemet's stripping automated endothelial keratoplasty, and histopathologic examination of the excised host tissue was performed., Results: Despite initial clearing of the donor lenticules, both eyes later experienced nonimmunologic graft failure, probably related to continued amantadine corneal toxicity. After discontinuation of the amantadine, one graft demonstrated partial clearing. Histopathology demonstrated endothelial cell loss. Specular microscopy demonstrated pleomorphism and disruption of the orderly hexagonal array., Conclusions: Chronic amantadine hydrochloride therapy may be responsible for irreversible corneal edema and may lead to graft failure in unrecognized cases.

The purpose of this study was to determine the effect of hypoxia on caspase-8 and -9 gene and protein expression and activity in corneal epithelium. Non-transformed human corneal epithelial cells (HCEC) were cultured in 2% oxygen. A cDNA expression array coupled with densitometric analysis was used to compare relative mRNA expression levels of 96 apoptosis-related genes in hypoxic and normoxic HCEC. Caspase-8, caspase-9, FLIP, Fas, FasL, and TNFalpha protein expression was assessed further using Western blot analysis and ELISA. Caspase-8 and -9 activities were measured using a fluorometric activity assay. Hypoxia did not affect caspase-8 or -9 gene or protein expression in HCEC, however caspase-9 activity was significantly increased. Hypoxia significantly suppressed the activity of caspase-8. FLIP and Fas gene and protein expression were not significantly altered in hypoxic cells compared to normoxic controls. mRNA and protein levels of TNFalpha and TNFR-1 were significantly decreased, while FasL mRNA and proteins levels were significantly increased in hypoxic HCEC. In corneal epithelium stressed by hypoxia caspase-9 activity is upregulated, suggesting that apoptosis proceeds via the mitochondrial pathway. Caspase-8 activity may be suppressed because the loss of TNFalpha and TNFR-1 gene and protein expression inhibits the initial formation of a death signaling complex.

Purpose: Corneal clarity is frequently reduced during vitrectomy and scleral buckling surgery secondary to epithelial edema, requiring epithelial debridement to improve visibility. The presence of toxic preservatives in the corneal lubricant solutions is hypothesized to be a contributing factor to epithelial edema during vitreo-retinal surgery., Design: Interventional study., Methods: We compared prospectively the corneal clarity and epithelial debridement frequency in 71 patients within a single institution in whom either Goniosol (2.5% methylcellulose, boric acid, edetate disodium, sodium borate, potassium chloride, water, and 0.01% benzalkonium chloride) or GenTeal gel (0.3% hydoxypropyl-methylcellulose, carbopol 980, phosphonic acid, sorbitol, water, and 0.028% sodium perborate) was used as a corneal lubricant during the course of vitrectomy surgery using sutured contact lenses. Corneal clarity was subjectively graded in a scale of I to IV during surgery. Statistical analysis was made between these two groups for parametric and categorical data., Results: All eyes started with a corneal clarity grade of I (best possible). Corneal clarity decreased significantly faster in eyes where Goniosol was used to a median grade of III at 1 hour of surgical time. In eyes where GenTeal gel was used, corneal clarity decreased much slower, to a median grade of I at 1 hour of surgical time. The difference in frequency of epithelial debridement was also statistically significant: 54% and 14% for Goniosol and GenTeal eyes, respectively. Other factors that may cause corneal epithelial edema and affect corneal clarity were not statistically different between the Goniosol and the GenTeal groups, including median operative time, estimated intraocular pressure, pre- and intraoperative topical solutions and medications, and number of prior ocular procedures., Conclusions: The use of GenTeal gel as a corneal lubricant maintains corneal clarity longer than Goniosol during the course of vitrectomy surgery using a contact lens viewing system, limiting the need for epithelial debridement.

Laminin 5 functions to promote cell-matrix adhesion and therefore is hypothesized to abrogate apoptosis initiated through the loss of epithelial cell contact with extracellular matrix. Laminin 5 levels are decreased in epithelial cells cultured in a hypoxic environment. Exposure of epithelial cells to hypoxia may induce apoptotic pathways transmitted through changes in mitochondrial membrane potential. Using an apoptosis assay based on mitochondrial membrane integrity, the effect of hypoxia (2% oxygen) on human corneal epithelial cell viability was determined. Both a virally transformed corneal epithelial cell line and third passage corneal epithelial cells were resistant to hypoxia-mediated apoptosis for up to 5 days in culture. However, at 7 days in culture, a statistically significant increase in apoptosis was noted in hypoxic corneal epithelial cells compared to normoxic (20% oxygen) controls. Increased apoptosis in hypoxic epithelium at 7 days in culture correlated with decreased deposition of laminin 5 into the extracellular matrix, as determined by western blot analysis and immunofluorescence microscopy. Additionally, the extracellular processing of the alpha3 and gamma2 chains of laminin 5 was negatively impacted by corneal epithelial cell exposure to hypoxia for 7 days. Treatment of human corneal epithelial cells cultured in 20% oxygen with function-inhibiting antibodies to laminin 5 for 2 or 3 days resulted in a statistically significant decrease in proliferation, and concomitant increase in apoptosis, compared with untreated normoxic controls. Based on these results, it appears that mechanisms of hypoxia-mediated apoptosis in human corneal epithelial cells may be initiated by the loss of processed laminin 5 in the extracellular matrix or by the loss of laminin 5-epithelial cell communication and transmitted through mitochondria.

Purpose: To compare neodymium:YAG (Nd:YAG) laser effects on acrylic, silicone, and poly(methyl methacrylate) (PMMA) intraocular lens (IOL) polymers., Methods: Ten Nd:YAG laser exposures were produced in each of 6 implantation-quality acrylic (Alcon MA60BM), silicone (Staar AQ1016), and PMMA (Alcon MC60BM) IOLs under identical conditions. Each polymer type was irradiated at 6 power settings (0.3, 0.5, 1.0, 1.5, 2.0, and 3.0 mJ) and at 2 focal points (midpoint of lens optic and on the posterior surface to which a cellophane membrane was affixed). The linear extent of the damage was measured using light microscopy. Specimens exposed to 1.0 mJ were processed for scanning electron microscopy., Results: The damage threshold (> or = 5 microns depth) was 0.3 mJ for silicone and 1.0 mJ for acrylic and PMMA IOLs. At the clinically relevant power levels, 1.0 to 2.0 mJ, the depth of damage in the acrylic polymer was 11.9 to 30.5 times less than the depth in the silicone polymer. Similarly, the depth of damage in the PMMA polymer was 5.4 to 52.6 times less than the depth in the silicone polymer. The morphologic pattern of damage in the silicone IOL showed a deep, irregularly configured trough with meandering tendrils. Acrylic IOL damage morphology consisted of an ameboid-shaped entry site without radiating fractures and mild posterior penetration. Poly(methyl methacrylate) IOL damage consisted of a shallow focal trough with radiating fractures., Conclusions: The silicone IOL polymer had the lowest threshold for laser-induced damage and greater linear extension of damage than the PMMA and acrylic IOL polymers. Poly(methyl methacrylate) and silicone polymers exhibited collateral damage or ejected particulates adjacent to the entry site, whereas the acrylic polymer showed a discrete locus of damage.

Background and Objective: To determine the effect of photorefractive keratectomy (PRK) on intraocular steroid penetration., Materials and Methods: To assess steroid penetration after PRK, four rabbits underwent unilateral myopic 9.90-D PRK procedures. The other eye was left undisturbed as a control. One week later both eyes received hourly doses of radiolabeled topical dexamethasone., Results: No significant difference in corneal tissue [(mean +/- 1 SD) PRK 4.8 +/- 1.1 micrograms/g, control 5.2 +/- 1.2 micrograms/g] or aqueous humor concentration [(mean +/- 1 SD) PRK 0.8 +/- 0.12 microgram/ml, control 0.9 +/- 0.05 microgram/ml] of dexamethasone was seen., Conclusions: Dexamethasone penetration in eyes 1 week following PRK is similar to that of the unablated cornea.

Purpose: To assess the use of corneal topography in conjunction with slitlamp biomicroscopy and retinoscopy to diagnose keratoconus in a large group of patients with Ehlers-Danlos syndrome (EDS)., Setting: Kresge Eye Institute, Wayne State University, Detroit, Michigan, USA., Methods: Thirty-six patients (72 eyes) with genetically typed EDS had slitlamp biomicroscopy, retinoscopy, and videokeratography with the EyeSys instrument. The presence or absence of slitlamp keratoconus findings was correlated to a presumptive diagnosis based on corneal topography using derived topographic indexes associated with keratoconus. These topographic indexes included central corneal power, (CCP), difference in CCP, inferosuperior asymmetry (I-S) value, and asphericity (Q). Axial and profile difference maps were generated and analyzed for findings suggestive of keratoconus., Results: In 72 eyes, no keratoconus was found using slitlamp biomicroscopy. No eye had an I-S value greater than 1.60 diopters (D), 2 eyes had a CCP greater than 46.50 D, and 2 eyes had a Q value less than -1.00. Eight of 36 pairs of eyes had an intereye CCP greater than 0.92 D. In both eyes of the patient with Q values less than -1.00 the profile difference maps were mildly abnormal., Conclusions: Slitlamp biomicroscopy of the cornea was unremarkable in all patients. Only 1 patient had Q values and profile difference maps that were mildly suggestive of keratoconus. Even after adding topography to the examination, it appears that keratoconus in a known population of patients with EDS remains rare.

Purpose: To compare the residual adherence of viscoelastics to the corneal endothelium following phacoemulsification in an in vitro rabbit model., Setting: Departments of Ophthalmology and Anatomy, Wayne State University, Detroit, Michigan, USA., Methods: Three groups of 10 rabbit eyes each had a lensectomy via phacoemulsification using sodium hyaluronate (Amvisc Plus, Healon GV) or sodium chondroitin sulfate-sodium hyaluronate (Viscoat) as the viscoelastic agent. After phacoemulsification and cortex removal, a central corneal block was excised, cryofixed, and processed for light and electron microscopy. Viscoelastic thickness was determined by a calibrated reticule on the light microscope or a calibrated measuring program in the electron microscope. The nonparametric statistical test, Kruskal-Wallis, was used to compare viscoelastic groups., Results: Median phacoemulsification time between viscoelastic agents was not significantly different. Median viscoelastic thicknesses were 13.0 microns for Amvisc Plus, 0.4 micron for Healon GV, and 375.0 microns for Viscoat. Each was significantly different from the others (Kruskal-Wallis, P < .001)., Conclusions: Median thickness of Amvisc Plus, Healon GV, and Viscoat remaining adherent to the corneal endothelium after phacoemulsification was markedly different. Viscoat provided the greatest amount of viscoelastic material adjacent to the corneal endothelium.

Background and Objective: To determine if the technical aspects of phacoemulsification for removal of cataract following pars plana vitrectomy differ from those of phacoemulsification for removal of cataract in nonvitrectomized eyes., Patients and Methods: Twenty-two eyes that had undergone prior vitrectomy were identified through a retrospective review of chart notes and operative records of 1039 consecutive cataract extractions performed by one surgeon., Results: Complications of proliferative diabetic retinopathy was the most common indication for prior vitrectomy. The predominant lens change was nuclear sclerosis. Deep anterior chambers with large anterior to posterior excursions of the iris lens diaphragm with simultaneous fluctuation in pupil size occurred during phacoemulsification. The posterior capsule was flaccid and mobile during lens cortex removal. No posterior capsules ruptured. Postoperative visual acuity improved in 91% of the patients., Conclusions: Prior vitrectomy was associated with diabetes and nuclear sclerotic cataract. Phacoemulsification in this patient population was associated with inadequate pupillary mydriasis, superior conjunctival scarring, intraoperative anterior chamber depth, pupil size, and iris lens excursions that hindered phacoemulsification tip placement. Posterior capsules were excessively flaccid, prone to rapid anterior and posterior excursions, and may have plaques that are resistant to intraoperative removal.

The authors describe the unexpected finding of cicatrization of posterior chamber lens haptics to the pars plana. This was found during removal of a secondary, transscleral sewn-in pseudophakos during a retinal reattachment procedure. Ophthalmic history and intraoperative photography revealed pars plana cicatrization of haptics. Despite removal of trans-scleral prolene fixation sutures and application of gentle traction, the posterior chamber lens haptics remained firmly adherent to pars plana retina. The haptics were amputated to prevent significant chorioretinal damage. The conventional belief that all sewn-in posterior chamber intraocular lenses cause little or no scarring response around the haptics may be unfounded.

Purpose: Possible toxic effects of ofloxacin on human corneal endothelia were assessed by using electron microscopy and in vitro specular perfusion., Methods: Five pairs of corneas [with one cornea of each pair receiving balanced salt solution (Endosol; Allergan, Irvine, CA, U.S.A.) and the other receiving Endosol with 10 micrograms/ml of ofloxacin] underwent perfusion for 3 h with corneal pachymetry every 15 min followed by tissue fixation. A mean corneal swelling rate was calculated from a first-order regression line fit for each of the five experiments. The swelling rates between groups was compared by-using a paired t test. Scanning and transmission electron micrographs were examined for cellular architecture. Another group of five pairs of corneas was perfused the same way with the only difference being a test dose of 30 micrograms/ml., Results: The mean swelling rate for corneas perfused with 10 micrograms/ml of ofloxacin of -3.5 microns/h was not significantly different from that of the Endosol-alone corneas at -3.0 microns/h (p = 0.71). The mean swelling rate for corneas perfused at 30 micrograms/ml of ofloxacin was -4.1 microns/h, not significantly different from Endosol-alone perfused corneas at -6.5 microns/h (p = 0.08). No consistent ultrastructural changes could be attributed to exposure to 10 or 30 micrograms/ml of ofloxacin., Conclusion: Human corneal endothelium can be exposed to ofloxacin at a dose of 30 micrograms/ml for a period of 3 h without adverse ultrastructural or physiologic side effects.

To assess whether a 4 mm scleral tunnel incision with a 1.5 mm internal corneal lip (three-step procedure) causes increased endothelial cell loss and damage to the cornea, we retrospectively evaluated the outcomes of 20 patients (40 eyes) who had a standard 4 mm scleral tunnel incision (two-step procedure) in one eye followed by a three-step incision in the second eye, with in situ phacoemulsification and insertion of a foldable silicone lens in each eye. Mean phacoemulsification time was 2.4 +/- 1.1 minutes for the two-step incisions and 3.4 +/- 1.4 minutes for the three-step incisions. Preoperative and postoperative endothelial cell counts were obtained to determine the effects of surgery on the corneal endothelium. Although the three-step procedure had a trend toward increased endothelial cell loss from the central corneal region compared with the two-step incision, the result was neither clinically nor statistically significant. The difference between the three-step and two-step incisions in postoperative endothelial cell counts from the superior corneal region was statistically significant. The difference in postoperative counts from the inferior region was not statistically significant. Although the three-step 4 mm incision does seem to affect the corneal endothelium, its clinical significance is unknown.

Objective: To investigate the ultrastructural and physiologic effects of exposure of the human corneal endothelium to mitomycin at concentrations of 20 micrograms/mL and 200 micrograms/mL using electron microscopy and in vitro specular perfusion techniques., Methods: Four pairs of corneas (with one cornea of each pair receiving balanced salt solution [BSS Plus, Alcon Laboratories, Fort Worth, Tex] and the other receiving BSS Plus with 20 micrograms/mL of mitomycin) suitable for transplantation, except for extremes of age or systemic disease, underwent perfusion with corneal thickness measured serially every 15 minutes followed by fixation for electron microscopy. Mean corneal swelling rate was calculated for all four experiments, and the control group that received BSS Plus was compared with the group that received mitomycin using a paired t test. Electron micrographs were examined in a masked fashion. Similar studies were performed using two pairs of corneas that received 200 micrograms/mL of mitomycin., Results: The mean swelling rate for corneas perfused with 20 micrograms/mL of mitomycin (-4.1 microns/h) was not significantly different from that seen in tissue perfused with BSS Plus (-4.2 microns/h). No consistent ultrastructural changes could be attributed to exposure to 20 micrograms/mL of mitomycin. Perfusions of mitomycin at 200 micrograms/mL resulted in prompt corneal swelling with marked ultrastructural alterations compared with tissue perfused with BSS Plus., Conclusion: Human corneal endothelium may be exposed to undiluted (200 to 500 micrograms/mL) mitomycin with inadvertent entry into the anterior chamber during dissection of the scleral flap bed in trabeculectomy followed by application of mitomycin. This will result in prompt destruction of the endothelium. Exposure to 20 micrograms/mL of mitomycin, a level exceeding the concentration that may be present in the aqueous humor after its proper application, appears nontoxic in this system.

Background: Long scleral tunnel dissection techniques have been developed for cataract surgery incisions. These incisions reduce postoperative astigmatism and keratorefractive instability. If fashioned correctly, the internal lip of the incision produces a tight seal to the anterior chamber, permissible of sutureless surgery. The behavior of such a wound during intraocular infection is unknown., Methods: The authors describe two elderly patients in whom postoperative bacterial endophthalmitis was accompanied by infectious scleritis, infectious sclerokeratitis or keratitis, and rapid scleral flap necrosis. One of the patients had a painless disease process., Results: Intraocular isolates of Staphylococcus aureus and Streptococcus equinus were recovered from the two patients, respectively. Management was complicated by loss of tectonic integrity that followed scleral flap necrosis, by impaired vitreoretinal visualization associated with rapidly progressive sclerokeratitis or keratitis, and by bacterial scleritis in the base of the scleral flap. No light perception was retained in either eye., Conclusion: Scleral tunnel incisions create a potential abscess cavity. Although a rare occurrence, postoperative endophthalmitis in such an eye may present major surgical and therapeutic problems intrinsic to the wound design.

Purpose: Use of fluoroquinolone agents as single drug treatment for severe bacterial keratitis requires that adequate stromal drug concentrations are achievable that exceed the MIC90 for common corneal pathogens. The purpose of this study, therefore, is to document the human stromal penetration of the fluoroquinolone, ciprofloxacin, in human tissue obtained from patients undergoing penetrating keratoplasty., Methods: Twelve patients, all with intact corneal epithelia, received 0.3% ciprofloxacin (Ciloxan) eyedrops every 15 minutes for the first hour and then every hour for 10 hours before their scheduled keratoplasty. Corneal tissue samples obtained from the excised buttons at the time of surgery were frozen and subsequently analyzed for drug concentration using high-pressure liquid chromatography., Results: A mean corneal tissue concentration of 5.28 +/- 3.4 micrograms/g tissue (mean +/- standard deviation) of ciprofloxacin was determined. Tissue levels ranged from 1.43 micrograms/g of tissue to 10.58 micrograms/g of tissue., Conclusion: Ciprofloxacin penetration was variable in patients with an intact epithelium and, in some cases, did not exceed the MIC90 for some gram-positive organisms. The presence of an epithelial defect is expected to potentiate the penetration of ciprofloxacin to most likely exceed the MIC90 for most corneal pathogens.

Implantation of a Molteno drainage shunt has been shown to be effective in advanced glaucoma. Foreign substances within the anterior chamber have been known to cause progressive endothelial cell loss. We undertook a study to evaluate the endothelial effects of an indwelling Molteno drainage shunt. Nineteen patients who underwent uneventful implantation of a Molteno drainage shunt for advanced aphakic or pseudophakic glaucoma were followed up. Serial endothelial cell counts were obtained in a masked fashion. During follow-up periods ranging from 5.4 to 25.7 months, endothelial cell loss averaged two cells per square millimeter per postoperative month with a 95% confidence interval of positive seven cells to negative ten cells per square millimeter per postoperative month. No clinically significant progressive trend in endothelial cell loss was seen in patients undergoing uncomplicated Molteno drainage procedures. Larger sample sizes with longer follow-up will be necessary to establish whether a Molteno drainage shunt causes clinically remarkable endothelial cell loss.

Variables in intraocular lens (IOL) power calculations include axial length, average dioptric power of the cornea, and an assumed pseudophakic anterior chamber depth (ACD). In the case of transscleral suture-fixated posterior chamber (PC) IOLs, ACD depends on the placement of the suture and thus might be expected to vary more than it does in eyes with capsular-fixated IOLs. To assess the degree of this variation, we determined the postoperative pseudophakic ACD using A-scan ultrasonography in 15 patients with transscleral suture-fixated PC-IOLs. The mean pseudophakic ACD (posterior corneal vertex to anterior pseudophakos) was 3.47 +/- 0.69 mm. The mean absolute discrepancies in ACD between these measured values and those predicted by the original Binkhorst and the most recent Holladay formulas were 0.579 +/- 0.513 mm and 0.639 +/- 0.519 mm, respectively. In 11 of 15 eyes, the measured ACD was within 1 mm of that predicted by either the Binkhorst or Holladay formula, suggesting that either will provide reasonable estimates of ACD for IOL power calculations for suture-fixated PC-IOLs.

Changes in the composition of stromal proteoglycans (PGs) have been previously demonstrated in corneal edema, wound healing, and disease. To examine if PGs are lost during corneal preservation, rabbit corneal PGs were radiolabeled in situ with 35S-sulfate and 3H-glucosamine, excised and stored in either modified McCarey-Kaufman medium (MMK), K-Sol (Coopervision-Cilco, Bellevue, WA, U.S.A.), corneal storage medium (CSM), or Dexsol (Chiron Ophthalmics, Irvine, CA, U.S.A.) for up to 14 days. The percentage of total radio-label lost was significantly greater from de-epithelialized corneas (p less than 0.05) and from corneas stored in CSM (p less than 0.05) or K-Sol (p less than 0.05). Corneas stored in CSM for 4 and 7 days were significantly more hydrated than corneas stored in MMK, K-Sol, or Dexsol. After 14 days of storage, all corneas were hydrated above control values with the Dexsol-stored cornea showing the least hydration. Results suggest that loss of stromal PGs during corneal storage is reduced with epithelial integrity and with preservation media containing dextran.

We have devised a new method to solubilize sclera in order to permit quantitative determination of tobramycin by commercially available and widely utilized means. The sclera, containing tobramycin, was digested with Alcalase (Subtilisn A, NOVO Enzymes) and the tobramycin level was quantitated by TDX autoflourophotometry. This technique is accurate and sensitive. The tissue digestion and antibiotic assay are relatively simple to perform and should be applicable to a variety of antibiotics and possibly other therapeutic agents.

Endothelial permeability (Pac) to carboxyfluorescein and Na+/K+ ATPase pump site density were determined in human corneas following storage for 4 or 7 days at 4 degrees C in either modified McCarey-Kaufman (mMK) or K-Sol media. Following 4 days of storage, Pac values for mMK- and K-Sol-preserved corneas were not significantly different from those of their prestorage mates. After 7 days of storage, however, corneas stored in K-Sol media showed a significant increase in Pac compared to their prestorage mates, whereas the mMK-stored corneas showed no change in Pac. Na+/K+ ATPase pump site density determined using [3H]ouabain was similar to a control group in the K-Sol-stored tissue but higher in the mMK-stored tissue following 7 days of storage. These studies suggest that mMK medium maintains endothelial barrier function and Na+/K+ ATPase pump site density at least as well as K-Sol medium through 7 days of corneal storage.

A mounting block for in vitro perfusion of the cat cornea is described. Using this apparatus and the techniques of Araie, the permeability (Pac) of the normal cat corneal endothelium to carboxyfluorescein was determined to be 2.5 +/- 0.2 x 10(-4) cm/min. To assess the sensitivity of this technique in determining changes in Pac associated with alterations in endothelial, morphology, three cats underwent 2 successive unilateral, central, 10 mm diameter circular areas of endothelial debridement 6 weeks apart. Six weeks following the second wounding all 3 animals underwent morphometric analysis and Pac determination. A trend toward an elevation in Pac with extreme reductions in cell density was observed.

We perfused the endothelia of isolated human corneas mounted in the specular microscope with BSS Plus containing 1,000-U/ml or 100-U/ml dilutions of two commercially available topical thrombin preparations. Corneas perfused with thrombin at 1,000 U/ml showed intracellular and intercellular vacuole formation and altered junctional complexes. As listed on the package inserts, the thrombin preparations contained preservatives and other additives that present a significant osmotic load in 1,000-U/ml preparations. Corneas perfused with 100-U/ml thrombin solutions showed a significant attenuation in their deswelling rate but no ultrastructural alterations. One available thrombin preparation when diluted to 100 U/ml had a glycine concentration associated with previous retinal electroretinography changes. Polyacrylamide gel electrophoresis of one manufacturer's thrombin solution showed multiple high and low molecular weight constituents. Analysis of particulate contamination showed one 100-U/ml thrombin preparation to have a large quantity of particulates. Although thrombin may be useful when applied topically as an aid in surgical hemostasis, its use intraocularly presents substantial concern regarding the preparation's purity, additives, contaminants, and adverse effects on ocular tissues.

Therapeutic use of contact lenses is an essential element in ophthalmic care. Materials currently in use include polymethyl methacrylate (PMMA), cellulose acetate butyrate, siloxane-containing polymethacrylates, silicones, and hydrogels. Suitability of a material for therapeutic contact lens use is determined by the physical, chemical, and mechanical properties (notably gas permeability and hydrophilicity, but also lipid absorption and lens movement, among others) and the condition to be treated; fabrication techniques are likewise important, affecting lens diameter and base curve. Selection and fitting of therapeutic contact lenses requires knowledge of how different contact lenses affect corneal physiology, as well as an understanding of the mechanisms whereby a contact lens can be therapeutic. In addition to these topics, general fitting guidelines are discussed, and results of therapeutic lens use in selected clinical situations (including recurrent erosion, metaherpetic ulcers and other epithelial defects, and keratitis sicca, and other dry eye states). Common therapeutic contact lens complications and their treatment are also discussed.

We reviewed the records of 20 consecutive eyes with pseudophakic bullous keratopathy associated with a closed-loop anterior chamber lens that underwent penetrating keratoplasty, total anterior vitrectomy, and anterior chamber intraocular lens exchange. On reexamination, all corneal grafts had remained clear during an average follow-up period of 15 months (range, four to 45 months). Seven eyes (35%) attained a visual acuity of 20/40 or better with spectacle correction; however, 15 of 20 eyes (75%) attained a best-corrected visual acuity of 20/40 or better using a pinhole and a gas-permeable contact lens. In five eyes visual acuity was 20/400 or poorer because of cystoid macular edema, as documented by fluorescein angiography, age-related macular degeneration, or optic atrophy. Localized, minimal peripheral anterior synechiae were present on gonioscopy in seven eyes. The one-piece flexible anterior chamber lens implants used for exchange appeared to be well tolerated in this series of patients.

Implantation of a hydrogel (IOGEL) intraocular lens in humans has been reported. The polyhydroxyethyl methacrylate (poly HEMA) matrix of this hydrogel is permeable to water soluble drugs and may adsorb agents used intracamerally during cataract extraction or topically during the postoperative period. This study compared the in vitro uptake and release of chloramphenicol, dexamethasone, epinephrine, pilocarpine, and bovine serum albumin by polymethylmethacrylate and hydrogel intraocular lenses with that of the intact crystalline lens of humans and rabbits. An in vivo study compared the uptake and release of chloramphenicol and dexamethasone by hydrogel lenses implanted in the anterior chamber of rabbit eyes with that of the rabbit's crystalline lens. The in vitro uptake and washout of epinephrine and pilocarpine by the hydrogel lens was comparable to the human lens. Uptake of chloramphenicol and dexamethasone by the hydrogel lens exceeded that of the human lens and, following a two-hour washout period, the dexamethasone content of the hydrogel lens remained significantly greater than the human lens. The uptake and washout of bovine serum albumin by the hydrogel lens was half that of the human lens. In vivo, the hydrogel lens efficiently eluted both chloramphenicol and dexamethasone. These studies show that a hydrogel lens will not act as a significant depot for drugs in the eye.

When viscoelastic agents that contain hyaluronate sodium are used during anterior segment surgical procedures, it is common for some of the material to remain intraocularly after the surgery is completed. A variety of drugs, used intracamerally or topically following surgery, are also present. These drugs may be bound to the polyanionic hyaluronate molecule. This occurrence may cause drug alterations in therapeutic effectiveness, pharmacokinetics, and toxicity. To investigate the possibility for drug-viscoelastic agent adsorption, in vitro drug-binding studies were performed on three commercial viscoelastic agents; undiluted aliquots of Amvisc, Healon, or Viscoat were mixed with radiolabeled D-threo-chloramphenicol, dexamethasone, L-epinephrine, or pilocarpine hydrochloride, placed in dialysis membranes, and dialyzed for 24 hours against an isotonic phosphate buffer. The calculated drug binding by a viscoelastic agent ranged from 0% to 1.5%. These extremely low values for in vitro drug uptake by viscoelastic agents made it unlikely that any significant drug-viscoelastic agent interaction would occur in the postoperative eye.

Endothelial permeability was examined in rabbit and human corneas using an in vitro perfusion system with 5(6)-carboxyfluorescein as the permeability tracer. Following endothelial removal, the permeability of de-epithelialized rabbit corneas increased from 3.19 x 10(-4) cm min-1 to 31.21 x 10(-4) cm min-1, and de-epithelialized human donor corneal permeability values increased from 2.26 to 12.85. In human corneas, no correlation was seen between endothelial permeability and donor age, moist chamber storage time, endothelial cell density, coefficient of variation of cell area, or percent hexagonal cells. A positive correlation was found between permeability and time between donor death and enucleation. Donor eyes from three separate populations, having undergone cataract surgery prior to death (aphakic, posterior and anterior chamber implants), all showed a significant increase in permeability. Neither Type I nor Type II diabetes had an effect on the endothelial permeability of human donor corneas.

The search for an ideal intraocular irrigating solution is of paramount importance to te ophthalmic surgeon. An intraocular irrigating solution, as well as surgical technique, can have deleterious effects on ocular tissues. Since an intraocular irrigating solution comes in contact with the cornea, lens, trabecular meshwork, uvea, vitreous, and retina, and ideal irrigant would be ome that ensures biological function for all of these tissues. In a practical sense, the best irrigant is one that causes the least possible damage to the structural integrity and function of the intraocular environment. This paper summarizes the development, uses, and efficacy of intraocular irrigating solutions as currently used during intraocular surgery.

Cynomolgus monkeys were anesthetized with either intravenous (IV) ketamine hydrochloride, IV ketamine and intramuscular (IM) diazepam, IM methohexital sodium and IM pentobarbital sodium, or endotracheal halothane. Intraocular pressure, aqueous humor flow rate (F), anterior chamber volume, corneal endothelial transfer coefficient (Ka), and anterior chamber elimination coefficient (Ke) were determined noninvasively, using applanation tonometry, keratometry, pachymetry, and fluorophotometry. Arterial blood gases (ABG), acid-base balance, and mean arterial pressure (MAP) were monitored. The IOP was highest with ketamine and lowest with pentobarbital. The F and Ke were about 30% lower with halothane than with the other regimens, while Ka was highest with ketamine. The ABG and MAP were within normal physiologic limits with the three noninhalation regimens; pH was within normal limits with all four regimens. The MAP was lowest and PO2 highest with halothane, while pH was highest with pentobarbital.