Search

Background:. Evaluation of practice patterns by American Board of Plastic Surgery (ABPS) diplomates allows for a greater understanding as to how the field is progressing. Understanding evolving procedural trends can give insight into plastic surgeons’ subspecialty focus and influence resident training to prepare them for future practice. Methods:. American Society of Plastic Surgeons member only projections for aesthetic and reconstructive procedures were reviewed from 1999 to 2018 in 5-year increments to identify shifts in frequency between the beginning (1999–2003) and end (2014–2018) of the timeframe. Tracer utilization for all four ABPS modules were also examined between 2014 and 2018. Descriptive statistics were performed to identify significant changes (P < 0.05) in subspecialty focus and procedure trends. Results:. Annual procedure incidence between 2014 and 2018 was compared with that between 1999 and 2003. The annual number of procedures more than doubled from 3,244,084 to 6,628,082. Among reconstructive procedures, there was a statistically significant increase in the number of breast reconstruction, breast implant removal, and maxillofacial surgery procedures, and a statistically significant decrease in the number of procedures focused on reconstruction of birth defects, burn injuries, and hand anomalies. In aesthetic surgery, significant increases were seen in the number of augmentation mammoplasty, abdominoplasty, and mastopexy procedures, with significant decreases in the number of blepharoplasty and rhinoplasty procedures. Conclusions:. Understanding the changing practice patterns of ABPS diplomates is essential to define the direction that our specialty is taking over time, and to guide program directors in plastic surgery on areas of focus for appropriate training of plastic surgeons.

Summary:. Asian rhinoplasty generally requires augmentation procedures rather than reduction. Alloplastic grafts are fraught with higher complication rates. Autologous cartilage grafts are safer. However, Asian patients typically do not have adequate septal cartilages, and other autologous cartilage grafts may cause surgical site morbidities, prolonged surgical time, and complications, including warping and infection. Asian rhinoplasties were performed using fresh frozen cartilage by the senior author. Patients’ demographics and medical histories were recorded. Anthropometric measurements (nasofrontal angle, nasofacial angle, nasolabial angle, and Goode ratio) were taken on two-dimensional photographs. FACE-Q scales were used to assess patient-reported outcomes. Five Asian patients underwent rhinoplasty using the fresh frozen cartilage and were followed up for an average period of 14.2 ± 3.35 months. There was no resorption, warping, or infection. Anthropometric measurements showed no significant changes 2–4 months or 8–20 months after surgery. At the time of the 1-year follow-up, mean FACE-Q Satisfaction with Nose, and Satisfaction with Nostrils scores improved from 35.2 ± 10.06 to 60 ± 15.48 (P = 0.0002), and 42.6 ± 20.31 to 59.8 ± 38.21 (P = 0.12), respectively. Fresh frozen cadaveric cartilage is a novel option for Asian rhinoplasty. Our study demonstrated its safety and satisfying surgical outcomes.

Purpose: To test the impact of professional management of soft contact lens wear on symptoms and ocular complications., Methods: Subjective symptoms and ocular complications of soft CL users who did not seek professional follow-up care (self-managed, SM), were compared to users who were prescribed CLs and their care professionally managed in optometry practices (PM), and to a control group of non-CL wearers. Habitual visual acuity, subjective dry-eye symptoms, and corneal abnormalities were assessed in all participants. CL wearers filled-out a usage habits questionnaire, and their CL fit was assessed. Outcomes were compared using Kruskal-Wallis and Chi Squared tests., Results: The SM, PM, and non-CL wearers cohorts included 127 (mean age:24.3±5.1, median:23, range:16-45 years,104 female), 132 (mean age:25.5±6.2, median:23, range:18-43 years,103 female), and 56 (mean age:22.3±3.5, median:21, range:18-39 years,36 female) participants, respectively. Meibomian gland dysfunction grade (p = 0.004, p<0.0001), limbal redness (both p = 0.04), corneal neovascularization (both p = 0.003), and papillary conjunctivitis (p<0.0001,p = 0.005) were significantly worse in SM CL wearers compared with both the non-CL wearers and PM CL wearers, respectively. Conjunctival staining was significantly worse in the SM cohort compared with the PM cohort (p = 0.01). 38.6% of the SM compared with 22.8% of the PM CL wearers, had an inappropriate refractive correction (p = 0.006). SM CL wearers wore CLs significantly more years (mean and median 1 year,p = 0.008), for more daily hours (mean and median of 2 hours,p<0.00001), and tended to nap or sleep with their CLs compared with the PM CL wearers (47 vs. 29,p = 0.02). The cohorts did not differ in their subjective symptoms., Conclusions: Complications are significantly more prevalent in SM CL wearers compared with PM CL wearers, and SM CL wearers tend to wear CLs with incorrect powers, and are less compliant with napping or sleeping with the CLs compared with PM CL wearers. These findings emphasize the importance of fitting, patient education and follow-ups in CL wearers., Competing Interests: Cooper-Vision Israel provided contact lens solutions that were provided to participants of the study. This does not alter our adherence to PLOS ONE policies on sharing data and materials. There are no patents, products in development, or marketed products associated with this research to declare., (Copyright: © 2024 Gantz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objectives: Limited literature supports the value of routine contact lens examinations. The purpose of this study is to document complications diagnosed when subjectively successful planned replacement soft contact lens patients are evaluated to renew their existing contact lens prescriptions., Methods: Asymptomatic soft contact lens patients who presented to the University Eye Center at Ketchum Health (Anaheim, CA) and the Eye and Vision Center at the Massachusetts College of Pharmacy and Health Sciences (Worcester, MA) for routine contact lens comprehensive exams to renew existing contact lens prescriptions were professionally evaluated and their complications documented. All subjects presented without complaint and had a history of subjectively successful planned replacement soft lens wear for at least 1 year., Results: A total of 202 subjects were recruited from both sites (age range 16-72 years; 76 male, 126 female; spherical contact lens optical power equivalent range: +7.75D to -19.25D). Considering health issues, one hundred and five (52%) patients were found to exhibit at least one undiagnosed complication (95% CI: 0.45-0.59): 70% were diagnosed with contact lens driven ocular complications; 54% were diagnosed with non-contact lens driven ocular health issues; and 4% showed signs of undiagnosed systemic disease. Of note, complication prevalence increases to 72% overall if both contact lens fit issues and contact lens care compliance problems are included as complications in analysis., Conclusions: A striking ocular health and contact lens complication rate in asymptomatic soft contact lens wearers is demonstrated across two different study sites. This data suggests that asymptomatic as well as symptomatic contact lens wearers require routine professional evaluations., (Copyright © 2020 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Objective: The purpose of this study is to determine the peripheral oxygen transmissibility (pDk/t) and respective central oxygen transmissibility (cDk/t) in soft contact lenses (SCLs) which might preclude SCL-driven corneal neovascularization (NV) in healthy myopic SCL users., Methods: Twenty subjectively successful SCL-wearing patients who presented with asymptomatic but active peripheral corneal NV (not ghost vessels) were recruited as study patients. Twenty-one patients who did not have NV were similarly recruited as controls. Demographic data were collected. Corneal NV was documented and photographed. Current habitual SCLs were collected and thicknesses measured to allow for the calculation of both pDk/t and cDk/t and estimation of local tear oxygen tensions., Results: No statistical differences between study and control groups in patient age, refraction, or the numbers of years, days per week, or hours per day patients reported SCL wear were identified. Statistically significant differences were found between the two groups for both pDk/t (P=0.006) and cDk/t (P=0.004): mean (±SD) pDk/t was 38.0±23.5 and 19.2±17.7 Fatt units for control and study corneas, respectively. Mean cDk/t were 80.0±54.4 and 36.8±33.1 Fatt units for control and study corneas, respectively. Peripheral tear oxygen tension that "protected" corneas from vascular filling was over 84 mm Hg., Conclusion: Maintaining a pDk/t above 30 to 40 Fatt units with daily wear SCLs should protect most normal corneas from NV as a complication of SCL wear.

Objectives: To quantify tear elimination rate (ER) underneath silicone hydrogel (Si-Hy) and scleral gas permeable (GP) contact lenses (CLs)., Methods: Subjects successfully using either well-fitting soft Si-Hy CLs or scleral GP CLs were recruited. Most scleral GP CL wearers had irregular corneas (e.g., keratoconus). An objective fluorometer measured decay of fluorescein isothiocyanate dextran dye signal (70 kD MW) from which the tear ER in %/min was calculated. For GP scleral lenses, the ER was determined for both the initial settling period and the 30- to 60-min period, and without lenses. All ERs were calculated from 5 to 30 min to avoid reflex tearing effects., Results: Fourteen soft Si-Hy CL and 12 scleral GP CL wearers completed the study. The ER for the scleral GP CL wearers averaged 0.57 (±0.6) %/min for the 0- to 30-min and 0.42 (±0.5) %/min for the 30- to 60-min period (P=0.515). Non-CL wear tear ER in these same subjects averaged 34.17 (±15.9) %/min and was significantly different versus both scleral GP wear periods (both P values <0.001). The ER for the soft Si-Hy CL wearers, 5 to 30 min, averaged 6.09 (±2.8) %/min., Conclusions: Our data demonstrate significantly less ER in well-fit scleral GP CL wearers compared with soft Si-Hy CL wearers for both the settling and longer wear periods (both P values <0.001). Moreover, slightly greater tear exchange was observed during the scleral GP CL settling period than later, which may reflect a change over time in tear vault thickness.

Purpose: Oxygen is essential for aerobic mammalian cell physiology. Oxygen tension (PO2) should reach a minimum at some position within the corneal stroma, and oxygen flux should be zero, by definition, at this point as well. We found the locations and magnitudes of this "corneal equilibrium flux" (xmin) and explored its physiological implications., Methods: We used an application of the Monod kinetic model to calculate xmin for normal human cornea as anterior surface PO2 changes from 155 to 20 mmHg., Results: We find that xmin deepens, broadens, and advances from 1.25 μm above the endothelial-aqueous humor surface toward the epithelium (reaching a position 320 μm above the endothelial-aqueous humor surface) as anterior corneal surface PO2 decreases from 155 to 20 mmHg., Conclusions: Our model supports an anterior corneal oxygen flux of 9 μL O2 · cm · h and an epithelial oxygen consumption of approximately 4 μL O2 · cm · h. Only at the highest anterior corneal PO2 does our model predict that oxygen diffuses all the way through the cornea to perhaps reach the anterior chamber. Of most interest, corneal oxygen consumption should be supported down to a corneal surface PO2 of 60 to 80 mmHg but declines below this range. We conclude that the critical oxygen tension for hypoxia induced corneal swelling is more likely this range rather than a fixed value.

Purpose: The main goal of this current work is to use an updated calculation paradigm, and updated boundary conditions, to provide theoretical guidelines to assist the clinician whose goal is to improve his or her scleral gas permeable (GP) contact lens wearing patients' anterior corneal oxygen supply., Methods: Our model uses a variable value of corneal oxygen consumption developed through Monod equations that disallows negative oxygen tensions within the stroma to predict oxygen tension at the anterior corneal surface of scleral GP contact lens wearing eyes, and to describe oxygen tension and flux profiles, for various boundary conditions, through the lens, tears, and cornea. We use several updated tissue and boundary parameters in our model. Tear exchange with GP scleral lenses is considered nonexistent in this model., Results: The majority of current scleral GP contact lenses should produce some levels of corneal hypoxia under open eye conditions. Only lenses producing the thinnest of tear vaults should result in anterior corneal surface oxygen tensions greater than a presumed critical oxygen tension of 100 mmHg. We also find that corneal oxygen tension and flux are each more sensitive to modification in tear vault than to changes in lens oxygen permeability, within the ranges of current clinical manipulation., Conclusions: Our study suggests that clinicians would be prudent to prescribe scleral GP lenses manufactured from higher oxygen permeability materials and especially to fit without excessive corneal clearance.

The cornea is precious to sight. Its intricate cellular arrangement and physiology enable it to be transparent and refractive. Corneal dystrophies (CDs) impact vision at various decades of life depending on the dystrophy at hand. Left untreated, visual ramifications ensue. This review article will summarize the current knowledge of the various CDs and the relatively controversial classification based on new genetic knowledge and clinical and histological characteristics. The application of contact lenses, both soft and rigid, has a place in the care and rehabilitation of these unique corneas.

Objective: We calculated corneal surface oxygen tension under hybrid contact lenses (CLs) by extending existing models of CL oxygen diffusion to the circumstances of hybrid CL designs with tear vaults., Methods: Theoretical oxygen tensions at the corneal surface, if tear mixing and exchange are excluded, are calculated for hybrid CL (modern, high oxygen-permeable rigid center) designs with a single chamber corneal model using a computer software spreadsheet. Several specific in vivo instances of hybrid CL tear vaults are measured by both slitlamp biomicroscopy and optical coherence tomography (OCT)., Results: No significant difference was found between central thickness of hybrid CL rigid portions measured by Vigor gauge and OCT. The amount of central tear vault thickness was found to be significantly greater, however, when interpolated from biomicroscope images (500-1,554 μm, simulating a poorly fit lens) than from either OCT images (0-91 μm) or direct measurement through OCT software (0-96 μm). Using all measurements, excluding any potential contributions from tear exchange or mixing, we predict corneal surface tear pO2 values under several hybrid CLs to range from zero under a lens with an excessive vault to 112 mm Hg under a lens with a minimal vault., Conclusions: Tear vaults beneath the gas permeable portion of the hybrid CLs of 100 μm or less resulted in acceptable corneal surface oxygen values. Where tear vaults are greater than about 100 μm, predicted anterior corneal surface pO2 values are less likely to be adequate for optimal corneal physiology. Any significant tear exchange, however, should increase these values. Although measuring tear thickness, we noted that the photographic biomicroscope and the OCT methods provided inconsistent results, and thus limited the reliability of our primary result.

Potent cholinesterase inhibitors such as sarin, induce an array of harmful effects including hypersecretion, convulsions and ultimately death. Surviving subjects demonstrate damage in specific brain regions that lead to cognitive and neurological dysfunctions. An early accumulation of acetylcholine in the synaptic clefts was suggested as the trigger of a sequence of neurochemical events such as an excessive outpour of glutamate and activation of its receptors. Indeed, alterations in NMDA and AMPA central receptors' densities were detected in brains of poisoned animals. Attempts to improve the current cholinergic-based treatment by adding potent anticonvulsants or antiglutamatergic drugs produced unsatisfactory results. In light of recent events in Syria and the probability of various scenarios of military or terrorist attacks involving organophosphate (OP) nerve agent, research should focus on finding markedly improved countermeasures. Caramiphen, an antimuscarinic drug with antiglutamatergic and GABAergic facilitating properties, was evaluated in a wide range of animals and experimental protocols against OP poisoning. Its remarkable efficacy against OP exposure was established both in prophylactic and post-exposure therapies in both small and large animals. The present review will highlight the outstanding neuroprotective effect of caramiphen as the optimal candidate for the treatment of OP-exposed subjects., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Purpose: The purpose of this study was to evaluate the complexity and effectiveness of fitting bitoric rigid gas permeable contact lenses (RGPCLs), compared to spherical RGPCLS, when used in the correction of high amounts of post-penetrating keratoplasty astigmatism., Methods: Records of post-penetrating keratoplasty (PKP) patients being managed with bitoric RGPCLs were compared to controls (post-PKP patients managed with spherical RGPCLs). Factors that were analyzed included the number of diagnostic RGPCLs used to assess the initial fit, the number of RGPCLs ordered to finalize the fit and the number of total doctor visits to finalize the fit., Results: Fourteen eyes of 14 patients satisfied the study criteria. The average amount of total astigmatism in this study group was 10.0D±5.0 compared to the control group which was 3.3D±2.6. The number of diagnostic RGPCLs used for the study group was 1.2±0.4 compared to 1.0±0.0 for the control group. The mean number of contact lenses ordered to complete the fitting for the study group was 1.9±0.7 compared to the control which was 2.1±0.8. The study group presented for an average of 6.3±1.6 visits whereas the control group presented for 4.9±1.1 visits. Contact lens corrected acuity for the study group was 0.101±0.11 (20/25) compared to the control group 0.08±0.12 (20/24)., Conclusions: The complexity of fitting bitoric RGPCLs was found to be similar to fitting spherical RGPCLs on post-PKP eyes and the visual outcomes were not different., (Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

We report the long-term clinical courses of 8 aphakic eyes of 2 sets of siblings who used contact lenses for both refractive correction and amblyopia treatment following neonatal cataract extraction. Early cataract removal, aggressive contact lens use, and robust professional supervision seem to have substantially contributed to visual success in our four patients. All eyes did well visually with contact lenses, all developing acuities close to 20/20 despite contact lens and non-contact lens related complications that were managed. Complications of most concern were corneal neovascularization and glaucoma. We believe this to be the first case series documenting consistent long-term visual and ocular health outcomes of sets of bilaterally aphakic siblings optically treated with contact lenses., (Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Objectives: This is a prospective study in an urgent-care ophthalmic setting to investigate contact lens (CL) complications and their association with extended wear (EW)., Methods: Data on CL designs, care system(s), and ocular complications were collected over a 6-month period., Results: One thousand three hundred and sixty-nine patients presented to the Jules Stein Eye Institute urgent care with symptoms of eye problems. Of these, 56 were identified with diagnoses etiologically associated with CL wear, and 49 were studied. The five most common ocular diagnoses found in our study were in the following order: epithelial staining or abrasion/epithelial defect, conjunctival injection, papillae, corneal neovascularization, and presumed microbial keratitis (PMK). Fifteen of 49 patients were diagnosed with PMK. The mean number of complications was 3.43 per eye. Most of the patients (65%) reported some form of EW. Analysis of the patients with PMK showed an association with EW. There seemed to be no statistical difference in the number of complications per symptomatic eye with hydrogel and silicone hydrogel lenses although 13 of the 15 patients with PMK were silicone hydrogel wearers., Conclusions: We studied various aspects of care and compliance in an urgent-care population and found that most of our urgent-care patients slept with CLs on their eyes. Symptomatic CL wear-related complications, and specifically MK, strongly correlate with EW with less relation to lens design, material, and wear modality. We therefore conclude that CL EW is a risk factor leading to urgent-care visits.

Some organophosphorus compounds (OPs) are nerve agents that continue to concern military personnel and civilians as potential battlefield and terrorist threats. Additionally, OPs are used in agriculture where they are associated with numerous cases of intentional and accidental misuse. These toxicants induce an array of deleterious effects including respiratory distress, convulsions and ultimately death. A mechanism involving a rapid and potent inhibition of peripheral and central cholinesterases leading to a massive buildup of acetylcholine in synaptic clefts was suggested as the underlying trigger of the toxic events. Indeed, therapy comprised of an acetylcholinesterase reactivator (i.e., oxime) and a cholinergic antagonist (e.g., atropine) is the accepted major paradigm for protection. This approach yields a remarkable survival rate but fails to prevent neurological and behavioral deficits. Extensive research revealed a complex picture consisting of an early activation of several neurotransmitter systems, in which the glutamatergic plays a pivotal role., Data accumulated in recent years support the concept that multi-targeting of pathways including glutamatergic and cholinergic circuits is required for an effective treatment. Drugs that demonstrate the ability to interact with several systems (e.g., caramiphen) were found to afford a superior protection against OPs as compared to specific antimuscarinic ligands (e.g., scopolamine). Compounds that potently block muscarinic receptors, interact with the NMDA ion channel and in addition are able to modulate σ(1) sites and/or GABAergic transmission seem to represent the emerging backbone for novel antidotes against OP poisoning. Several multifunctional drugs are already used for complex diseases e.g., cancer and depression., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

The main injuries among victims of the terrorist act in the Tokyo subway resulted from sub-lethal inhalation and whole body exposure to sarin vapor. In order to study the long term effects of such exposure and to simulate these conditions, freely moving rats were exposed to sarin vapor (27.2±1.7 μg/l) for 10 min. About 50% of the rats showed no overt symptoms and the rest had mild to moderate clinical symptoms that subsided within 4h following exposure. A reduction of weight was noted during the first 3 days with full recovery on the 4th day. Rat's heart was challenged with epinephrine 1 and 6 months post exposure. A significant reduction in the threshold for epinephrine-induced arrhythmia (EPIA) was noted in rats exposed to sarin. A time dependent increase in the kD and Bmax values of muscarinic auto receptors (M2) was recorded in the rat's cortex and striatum. No changes were recorded in the rats' brain trans locator protein (TSPO) levels, concomitant with no observed changes in the animals' performance in A Morris water maze test. A significant increase in open field activity was noted 6 months following exposure to sarin vapor as well as a significant decrease in prostaglandin E₂ (PGE₂) production in the brain. It is speculated that down regulation of the M2 auto receptor function, caused hyper reactivity of the cholinergic system which leads to the changes described above. The continuous reduction in M2 auto-receptor system through an unknown mechanism may be the cause for long lasting decline in sarin-exposed casualties' health., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Sulfur mustard (HD), a very potent alkylating agent and lipopolysacchride (LPS), are both well characterized inflammatory factors. We have found that concomitant exposure of murine macrophage cells (RAW264.7) to LPS and HD induced protection against HD induced cytotoxicity. Both HD and LPS induce release of inflammatory markers in RAW264.7 cells. However, there are marked differences in the repertoire of inflammatory factors released by the two toxins: While exposure to HD, induced a dose-dependant death of these cells, no significant change in survival rate was observed following LPS (1-100 ng/ml) exposure. Additionally, LPS elicited a robust nitric oxide (NO) and TNF-alpha secretion whereas HD was practically ineffective. Both toxins increased PGE(2) secretion in a concentration dependent manner. Treatment of HD-exposed RAW264.7 cells with anti-inflammatory drugs such as dexamethazone (5 muM), voltaren (diclofenac) (8 muM) or doxycycline (5 muM), decreased the release of cytokines but had no effect on cell viability. Simultaneous application of LPS (100 ng/ml) and HD (20-100 muM) resulted in an amelioration of HD cytotoxicity. Adding the NO generator S-nitrosoglutathione (GSNO) or inhibiting NO production using L-N(G)-monomethyl Arginine, had no effect on cell viability. Moreover, addition of PGE(2) (20 ng/ml) failed to induce any changes in cell viability under basal or HD-induced toxicity. In contrast, TNF-alpha (20 ng/ml) provided remarkable protection against HD-induced cell death. These findings strongly suggest that LPS exerts its protective action against HD toxicity through the generation of TNF-alpha and may provide better understanding of the mechanism of cytoprotection.

Objectives: To evaluate which factor(s) might predict excellent Snellen visual acuity results in unilateral nontraumatic pediatric aphakes., Methods: Retrospective review of all unilateral pediatric aphakic patients seen in a specialty contact lens clinic between 1982 and 2009. Inclusion criteria as follows: (1) cataract extraction before age 6 weeks, (2) no other health complications, (3) contact lens fitting within 3 weeks postsurgery, and (4) measurable subjective visual performance on a clinical Snellen acuity chart. Fifteen patients were identified: 10 patients with persistent fetal vasculature syndrome (PFV) and 5 patients with the diagnosis of idiopathic congenital cataract (ICC)., Results: Final Snellen acuity results showed seven patients (46.67%) developed excellent Snellen visual acuities (defined as 20/50 or better), four patients (26.67%) developed moderate Snellen visual acuities (20/125 to 20/60), and four total patients (26.67%) developed poor Snellen visual acuities (worse than 20/200). Analysis used descriptive statistics., Conclusions: Approximately 50% of our unilateral nontraumatic pediatric aphakic patients aged older than 5 years achieved excellent Snellen visual acuity in the aphakic eye. The amount of surgical or ocular complications seems to have an inverse relationship with Snellen visual acuity in PFV. Patching compliance, without implying cause-effect direction, also had a direct relationship with final Snellen visual acuity for patients. Early cataract extraction, good to moderate patching compliance, and aggressive early contact lens management can lead to moderate to excellent Snellen visual results in several unilateral pediatric aphakic patients.

The hormonal changes associated with immobilization stress (IMO) include a swift increase in corticosterone (CORT) concentration and a decrease in circulating testosterone (T) levels. There is evidence that the production of the short-lived neuromodulator nitric oxide (NO) is increased during stress in various tissues, including the brain. NO also suppresses the biosynthesis of T. Both the inducible and the neuronal isoforms of NO synthase (iNOS and nNOS, respectively) have been implicated in this suppression, but the evidence has not been conclusive. We used adult wild-type (WT) and nNOS knockout male mice (nNOS-/-) to assess the respective roles of CORT and nNOS-derived NO in stress mediated inhibition of T production. Animals were assigned to either basal control or 3-hour IMO groups. No difference in basal plasma and testicular T levels were observed between WT and nNOS-/-, although testicular weights of mutant mice were slightly lower compared to WT animals. The plasma contents of luteinizing hormone (LH) and CORT in unstressed mice of both genotypes were similar. Exposure to 3 hours of IMO increased plasma CORT and decreased T concentrations in mice of both genotypes. However, comparable levels of plasma LH and testicular nitrite and nitrate (NOx), NO stable metabolites, were detected in control and stressed WT and nNOS-/- mice. Adrenal concentrations of NOx declined after IMO, but the reduction was not statistically significant. These findings implicate CORT rather than NO generated by nNOS in the rapid stress-induced suppression of circulating T.

Purpose: This study is a cross-sectional analysis of the types and prevalence of contact lens (CL)-related complications among CL wearing patients seen in a university clinic setting., Methods: Data on CL material and design, care system, and ocular complications were recorded and statistically analyzed for CL wearers., Results: Of the 572 patients (846 eyes) recruited during the study, approximately 50% of the eyes had at least one CL-related complication. Rigid gas permeable (GP) CLs had a statistically lower (P<0.01) average number of complications (0.54 +/- 0.68) than soft contact lenses (SCLs) (0.85 +/- 0.82). Papillae and giant papillary conjunctivitis were the most prevalent complications in both GP and SCL wearers. Silicone SCLs (0.79 +/- 0.76) had a slightly lower, although not statistically different (P=0.23), rate of complication than nonsilicone SCLs (0.90 +/- 0.87). Although not statistically significant (P=0.29), extended wear CL use had a higher complication rate (0.93 +/- 0.84) compared with daily wear (0.73 +/- 0.79). Use of "other" solution, including generic and private label solutions, had the highest rate of complications for both SCLs (1.11 +/- 1.27) and GPs (0.96 +/- 0.93) compared with name brand solutions., Conclusions: The prevalence of CL-related complications, regardless of lens design, material, and wear modality, highlights the importance of early detection with appropriate professional management and treatment.

Purpose: Traumatic aniridia is often associated with severe anterior segment disruption, resulting in aphakia and corneal irregularity. Previous treatments included corneal tattooing and prosthetic contact lens correction. In the last 15 years, artificial iris implants have been demonstrated as safe and efficacious for reducing glare. Corneal scarring and irregularity from trauma still need to be addressed after artificial iris implantation., Method: This case report describes a patient who was rehabilitated with a custom rigid gas permeable contact lens after Morcher iris reconstruction lens implantation., Results: The patient experienced a significant decrease in photophobia glare sensitivity and achieved mechanical, physiologic and optical success, but only limited tolerance with the contact lens., Conclusions: Iris reconstruction lens implantation followed by rigid contact lens fitting is an option for correcting the aperture and optical defects of traumatic aniridia.

Potent cholinesterase inhibitors (e.g., soman, sarin), induce a wide range of deleterious effects including convulsions, behavioral impairments and ultimately, death. Due to the likelihood of various scenarios of military or terrorist attacks by these and other chemical weapons, research has to be aimed at finding optimal therapies. Early accumulation of acetylcholine in synaptic clefts was suggested to trigger an array of toxic events including an excessive release of glutamate, culminating in the activation of its receptors. Stimulation of the N-Methyl-D-Aspartate (NMDA) subtype of these receptors was associated with the neuronal injury that initiates organophosphate-induced brain damage. The notion of a stepwise mechanism yielded treatments based on a combination of an immediate administration of enzyme reactivators and anticholinergic drugs. This strategy dramatically increased survival rates but did not abolish convulsions and failed to prevent the ensuing cognitive dysfunction. Efforts to improve this paradigm by adding anticonvulsants or antiglutamatergic drugs with anti-epileptic characteristics produced dubious results. Under these conditions, benactyzine and caramiphen, agents with anticholinergic and antiglutamatergic properties, provided improved protection when introduced as adjunct agents to oximes, reversible cholinesterase inhibitors and/or specific antimuscarinic drugs such as atropine. In contrast, the specific antimuscarinic drug scopolamine failed to block soman-induced changes in glutamatergic and behavioral parameters even when given prophylactically. These findings along with a large number of additional reports led towards the conclusion that the therapeutic advantage of drugs such as benactyzine and caramiphen could derive from their ability to modulate central cholinergic and glutamate neurotransmission.

Introduction: The goal of this study was to apply a theoretical analysis of the relationship between contact lens oxygen transmissibility and tear layer oxygen tension to silicone hydrogel toric lenses and thereby model the success of such lenses in decreasing corneal hypoxia., Method: Lens thickness was measured at different points along the vertical meridian of one prism-ballasted, one dynamic-stabilized silicone hydrogel toric lens design, and one control "traditional" hydrogel toric lens design. Using lens thickness measurements and the nominal oxygen permeability values of these three lens designs, the subsequent oxygen tension in the tear layer trapped between the contact lens and the anterior cornea (P2) were calculated for both open- and closed-eye conditions using a single corneal chamber model with a personal computer program., Results: We found that cylindrical powers, regardless of lens materials, did not have a statistically significant effect on lens thickness (F=0.30, p=0.5834) to the limitation of our measurements, while contact lens type, spherical power, location on lens, and axis of cylindrical power were all found to do so. When multi-factor ANOVA was applied to the lens thickness and P2 data, contact lens location had a statistically significant effect on P2 values for both prism-ballasted (F=640.16, p<0.0001) and dynamic-stabilized toric lenses (F=352.85, p<0.0001). When the same statistical methodology was used to compare the relative performance of all three lenses on P2 during daily wear, the average P2 values for the three different lens brands were all statistically significantly different, while under closed-eye conditions the average P2 values for both silicone hydrogel toric lenses were no longer statistically significantly different (F=1.00, p=0.3178)., Conclusion: Assuming that the critical P2 was 100 mmHg, we predicted that silicone hydrogel toric soft lenses would provide reasonable anterior corneal oxygenation, certainly much enhanced over the environment predicted under traditional hydrogel designs, especially during daily (e.g. open eye) wear. Substantial corneal hypoxia continued to be predicted during extended wear of all lenses, but especially so with the use of traditional hydrogels.

The highly toxic organophosphorous compound VX [O-ethyl-S-(isoporopylaminoethyl) methyl phosphonothiolate] undergoes an incomplete decontamination by conventional chemicals and thus evaporates from urban surfaces, e.g., pavement, long after the initial insult. As a consequence to these characteristics of VX, even the expected low levels should be examined for their potential to induce functional impairments including those associated with neuronal changes. In the present study, we developed an animal model for subchronic, low-dose VX exposure and evaluated its effects in rats. Animals were exposed to VX (2.25 microg/kg/day, 0.05 LD(50)) for three months via implanted mini osmotic pumps. The rapidly attained continuous and marked whole-blood cholinesterase inhibition (approximately 60%), fully recovered 96 h post pump removal. Under these conditions, body weight, blood count and chemistry, water maze acquisition task, sensitivity to the muscarinic agonist oxotremorine, peripheral benzodiazepine receptors density and brain morphology as demonstrated by routine histopathology, remained unchanged. However, animals treated with VX showed abnormal initial response in an Open Field test and a reduction (approximately 30%) in the expression of the exocytotic synaptobrevin/vesicle associate membrane protein (VAMP) in hippocampal neurons. These changes could not be detected one month following termination of exposure. Our findings indicate that following a subchronic, low-level exposure to the chemical warfare agent VX some important processes might be considerably impaired. Further research should be addressed towards better understanding of its potential health ramifications and in search of optimal countermeasures.

Freely moving rats were exposed to sarin vapor (34.2+/-0.8 microg/l) for 10 min. Mortality at 24 h was 35% and toxic sings in the surviving rats ranged from sever (prolonged convulsions) through moderate to almost no overt signs. Some of the surviving rats developed delayed, intermittent convulsions. All rats were evaluated for long-term functional deficits in comparison to air-exposed control rats. Histological analysis revealed typical cell loss at 1 week post inhalation exposure. Neuronal inflammation was demonstrated by a 20-fold increase in prostaglandin (PGE(2)) levels 24 h following exposure that markedly decreased 6 days later. An additional, delayed increase in PGE(2) was detected at 1 month and continued to increase for up to 6 months post exposure. Glial activation following neural damage was demonstrated by an elevated level of peripheral benzodiazepine receptors (PBR) seen in the brain 4 and 6 months after exposure. At the same time muscarinic receptors were unaffected. Six weeks, four and six months post exposure behavioral evaluations were performed. In the open field, sarin-exposed rats showed a significant increase in overall activity with no habituation over days. In a working memory paradigm in the water maze, these same rats showed impaired working and reference memory processes with no recovery. Our data suggest long lasting impairment of brain functions in surviving rats following a single sarin exposure. Animals that seem to fully recover from the exposure, and even animals that initially show no toxicity signs, developed some adverse neural changes with time.

Sarin, a potent cholinesterase inhibitor, induces an array of toxic effects including convulsions and behavioral impairments. We report here on the protection provided by post-exposure antidotal treatments against a lethal dose of sarin (1.2xLD50) by scopolamine, benactyzine, trihexyphenidyl or caramiphen, administered 5, 10 or 20 min after the initiation of convulsions. A mixture of the oxime TMB4 and atropine (TA) was injected 1 min following poisoning a paradigm that may represent a scenario reminiscent of a terror incident. Surviving TA-treated rats exhibited marked tonic-clonic convulsions, weight loss, poor clinical status and abnormal cognitive performance as assessed by the Morris water maze. Additionally, a dramatic increase in the density of peripheral benzodiazepine receptors (PBRs), a faithful marker for neuronal damage, was noted. Animals treated 5 min after the development of toxic signs with benactyzine, trihexyphenidyl or caramiphen demonstrated control levels of PBR values, whereas scopolamine produced binding densities significantly above basal levels. Examined at the 10-min time point, scopolamine and trihexyphenidyl afforded no protection against brain damage and did not differ from TA-injected rats. All four drugs failed to significantly prevent the alterations when applied 20 min after onset of convulsions. Assessment of learning processes yielded similar results, where caramiphen exibited some protection at the 20-min time point. Our results show that caramiphen and benactyzine, agents with combined anticholinergic and antiglutamatergic pharmacological profiles, offer considerable shielding against sarin, even when their administration is delayed.

Purpose: Patients who have received Radial Keratotomy (RK) often require custom rigid gas permeable (GP) contact lenses to correct residual refractive errors post surgery. This paper is a long-term extension of a case report originally published in 1988 describing the course of a post-RK patient fitted with ortho-K design GP lenses., Methods: Visual acuities (VA), corneal curvatures, and refractive errors were collected from both the patient's medical record and the original case report published in 1988. These data were then plotted on graphs to observe the long-term effects of RK and rigid contact lens wear., Results: Although there was substantial fluctuation in refractive errors, VAs, and corneal curvatures shortly following RK, the patient's long-term results post-RK have remained relatively stable for the past decade., Conclusions: Although RK decreased our patient's myopia for about 6 diopters per eye, ortho-K appeared ineffective for our patient over the long term. It is important for practitioners to know the process involved in treating post-RK patients and to understand that large overall lens diameters, sometimes reverse geometry design, GP lenses with good edge lifts, often provide reasonable mechanical and physiological fits while optimizing visual outcomes for these patients.

Purpose: To describe an interesting case in which use of standard corneal topography in isolation from clinical observations could have misdiagnosed keratoconus as regular astigmatism., Methods: Single patient case report., Results: Our patient received the correct diagnosis and appropriate contact lens treatment that resulted in optimal vision and tolerance. CONCLUSIONS. Use of either or both careful clinical slit lamp biomicroscopy and history or more sophisticated corneal topography analysis can detect keratoconus that standard corneal topography used in isolation from other clinical investigations may misdiagnose.

Purpose: Case report on the clinical implications of mini-scleral gas-permeable contact lenses in the treatment of corneal disorders., Methods: Three patients with different corneal disorders were fitted with Jupiter design mini-scleral gas-permeable contact lenses., Results: All three patients achieved excellent vision and comfort. The contact lenses were tolerated well, and no complications were observed., Conclusions: Mini-scleral gas-permeable contact lenses provide a good option for patients who require gas-permeable contact lenses for optimal visual function but do not tolerate corneal contact lenses. Mini-scleral lenses are also an excellent therapeutic tool in the treatment of at least some forms of severe dry eyes.

Immobilization stress (IMO) induces a rapid increase in glucocorticoid secretion [in rodents, corticosterone CORT)] and this is associated with decreased circulating testosterone (T) levels. Nitric oxide (NO), a reactive free radical and neurotransmitter, has been reported to be produced at higher rates in tissues such as brain during stress. The biosynthesis of T is also known to be dramatically suppressed by NO. Specifically, the inducible isoform of nitric oxide synthase (iNOS) was directly implicated in this suppression. To assess the respective roles of CORT and NO in stress-mediated inhibition of T production, adult wild-type (WT) and inducible nitric oxide synthase knockout (iNOS(-/-)) male mice were evaluated. Animals of each genotype were assigned to either basal control or 3-h IMO groups. Basal plasma and testicular T levels were equivalent in both genotypes, whereas testicular weights of mutant mice were significantly higher compared with WT animals. Exposure to 3-h IMO increased plasma CORT and decreased T concentrations in mice of both genotypes. Testicular T levels were also affected by stress in WT and mutant males, being sharply reduced in both genotypes. However, the concentrations of nitrite and nitrate, the stable metabolites of NO measured in testicular extracts, did not differ between control and stressed WT and iNOS(-/-) mice. These results support the hypothesis that CORT, but not NO, is a plausible candidate to mediate rapid stress-induced suppression of Leydig cell steroidogenesis.

Purpose: To identify baseline demographic and clinical factors associated with undergoing penetrating keratoplasty (PK) in a prospective cohort of 1,065 keratoconus patients followed for eight years in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study., Design: Multicenter, prospective, observational cohort study., Methods: We report the rate of PK over eight years and baseline factors predictive of PK in 1,065 patients who, at the time of study enrollment, had not undergone PK in either eye., Results: Eighty-two percent of patients completed the eight-year close-out visit. Twelve percent (126 of 1,065) had PK in one (9.3%) or both eyes (2.5%). Baseline factors associated with increased likelihood of PK included younger age, steeper keratometric values, worse visual acuity, corneal scarring, poorer contact lens comfort, and poorer vision-related quality of life. The percent of eyes undergoing PK was 15% for patients 40 years old and younger, 28% for eyes with a steep keratometric value greater than 52 diopters, 33% for visual acuity less than 20/40, and 24% for eyes with corneal scarring., Conclusions: The CLEK Study confirmed previous reports of the increased likelihood of PK associated with corneal scarring, steeper keratometry values, poorer visual acuity, and poorer contact lens comfort. The CLEK Study is among the first to report an increased risk of PK associated with younger age, worse vision-related quality of life, and flatter contact lens fits. Knowledge of these factors is beneficial to clinicians in patient education and may be useful in disease management.

Background: Models of oxygen delivery to the cornea with contact lens wear have considered the customary situation of one lens being worn on the cornea. However, two lenses, such as a rigid lens piggybacked on a soft lens, may be worn by patients with special ocular and visual needs. This paper extends existing single lens models to circumstances where two lenses offer resistance to oxygen in series., Methods: Theoretical oxygen tensions are calculated for tear layers trapped beneath piggyback contact lens systems (and scleral lenses) and the anterior corneal surface with a simple single chamber corneal model using a personal computer software spreadsheet., Results: Acceptable values are anticipated for contact lens materials of modern oxygen permeability values of approximately 60-100 Fatt Dk units under open eye conditions., Conclusions: The results of this spreadsheet model of oxygen supply to the anterior corneal surface offer a useful guide to clinicians concerned about providing their patients with physiologically acceptable piggyback lens systems.

Epinephrine-induced arrhythmias (EPIA) are known to be associated with local cardiac cholinergic activation. The present study examined the development of QT prolongation and the effect on EPIA of whole-body exposure of animals to a potent acetylcholine esterase inhibitor. Freely moving rats were exposed to sarin vapor (34.2 +/- 0.8 microg/liter) for 10 min. The electrocardiograms (ECG) of exposed and control animals were monitored every 2 weeks for 6 months. One and six months post exposure, rats were challenged with epinephrine under anesthesia, and the threshold for arrhythmias was determined. Approximately 35% of the intoxicated rats died within 24 h of sarin exposure. Additional occasional deaths were recorded for up to 6 months (final mortality rate of 48%). Surviving rats showed, agitation, aggression, and weight loss compared to non-exposed rats, and about 20% of them experienced sporadic convulsions. Sarin-challenged rats with severe symptoms demonstrated QT segment prolongation during the first 2-3 weeks after exposure. The EPIA that appeared at a significantly lower blood pressure in the treated group in the first month after intoxication lasted for up to 6 months. This decrease in EPIA threshold was blocked by atropine and methyl-atropine. Three months post exposure no significant changes were detected in either k(D) or B(max) values of (3)H-N-methyl scopolamine binding to heart homogenates, or in the affinity of carbamylcholine to cardiac muscarinic receptors. The increase in the vulnerability to develop arrhythmias long after accidental or terror-related organophosphate (OP) intoxication, especially under challenging conditions such as stress or intensive physical exercise, may explain the delayed mortality observed following OP exposure.

Purpose: To evaluate the authors' experience fitting patients with pellucid marginal corneal degeneration (PMCD) with bitoric gas-permeable contact lenses., Methods: The records of 11 patients with a confirmed diagnosis of PMCD were retrospectively reviewed. The numbers of diagnostic contact lenses at the first visit, office visits, and lenses ordered to complete the fitting; uncorrected, spectacle-corrected, and contact lens-corrected Snellen visual acuities; contact lens success or failure; and complications encountered were all assessed. These data were compared to historic data for patients with other corneal irregularities (keratoconus, penetrating keratoplasty, and refractive surgery)., Results: The mean number of diagnostic contact lenses used at the first visit was 1.09 +/- 0.302, and the number of lenses ordered to complete the fitting was 1.82 +/- 1.33. The number of visits during 4 months was 6.18 +/- 2.14. Uncorrected visual acuity (logMAR) was 0.957 +/- 0.398 (20/181 in Snellen); the best-corrected spectacle visual acuity (logMAR) was 0.231 +/- 0.309 (20/34 in Snellen); and the best contact lens-corrected visual acuity (logMAR) was 0.0424 +/- 0.06275 (20/22 in Snellen). Corrected vision in eyes with PMCD improved approximately two lines with bitoric gas-permeable contact lenses compared to that achieved with spectacles. Ten (91) of the patients met the criteria of contact lens success during the 4-month follow-up period., Conclusions: Bitoric gas-permeable contact lenses achieved a comfortable and visually successful fit in most eyes with PMCD. Patients with PMCD used the fewest contact lenses and had the fewest lens exchanges, but required more office visits than other groups of patients with various corneal irregularities.

The free radical nitric oxide (NO), generated through the oxidation of L-arginine to L-citrulline by NO synthases (NOSs), has been shown to inhibit steroidogenic pathways. NOS isoforms are known to be present in rat and human testes. Our study examined the sensitivity of Leydig cells to NO and determined whether NOS activity resides in Leydig cells or in another cell type such as the testicular macrophage. The results showed a low level of L-[14C]arginine conversion in purified rat Leydig cell homogenates. Administration of the NOS inhibitor L-N(G)-nitro-arginine methyl ester (L-NAME), or the calcium chelator ethylenebis (oxyethylenenitrilo)tetraacetic acid (EGTA), had no effect on L-[14C]citrulline accumulation. Increased intracellular Ca2+ concentrations that were induced by a calcium ionophore, or the addition of luteinizing hormone (LH), failed to affect NO formation in intact cells that were cultured in vitro. Introduction of a high concentration of the NO precursor L-arginine did not decrease testosterone (T) production, and NOS inhibitors did not increase T biosynthesis. However, exposing Leydig cells to low concentrations of the NO donor S-nitrosoglutathione (GSNO) induced a dramatic blockade of T production under basal and LH-stimulated conditions. DNA array assays showed a low level of expression of endothelial NOS (eNOS), while the neuronal and inducible isoforms of NOS (nNOS and iNOS) were below detection levels. Reverse transcriptase-polymerase chain reaction (RT-PCR) analyses confirmed these findings and demonstrated the presence of high iNOS messenger RNA (mRNA) levels in activated testicular macrophages that produced large amounts of NO. These data suggest that, while T production in rat Leydig cells is highly sensitive to NO and an endogenous NO-generating system is not present in these cells, NOS activity is more likely to reside in activated testicular macrophages.

Several drugs of abuse are known to produce an array of deleterious effects, including alterations in neuronal circuitry and, ultimately, neuronal degeneration. For instance, methamphetamine was shown to induce substantial nigrostriatal dopaminergic terminal damage, including an increase in glial fibrillary acidic protein, a marker for astrocyte proliferation. Nevertheless, there was almost no attempt to define neurodegeneration by measuring the abundance of reactive microglia. In fact, some investigators fail to differentiate between astrocytes and microglia and claim glial fibrillary acidic protein to be a marker for gliosis. To date, there are numerous methods designed to assess brain neuropathologies resulting from a wide arsenal of insults. Regardless of the cause of neuronal damage, reactive glial cells always appear at and around the site of degeneration. These cells are distinguished by the exceptional abundance of peripheral benzodiazepine receptors (PBRs; omicron3 sites), particularly as compared to surrounding neurons. Measuring the binding of specific ligands to these PBRs (for example, [3H]PK 11195) offers a unique indirect marker for reliable impairment estimation in the central nervous system. Moreover, the availability of agents such as [11C]PK 11195 paved the road to in vivo animal and human brain positron emission tomography scanning, demonstrating inflammation-like processes in several diseases. Additionally, the measurement of increased binding of PBR ligands provides a faithful indicator for the behavioral and cognitive deficits accompanying neuronal injury.

Purpose: To report the utility of genetic testing in the diagnosis and management of patients with suspected corneal dystrophies., Design: Case report., Methods: A 58-year-old man with a history of recurrent corneal erosions was diagnosed with bilateral anterior basement membrane dystrophy and unilateral lattice corneal dystrophy. All 17 exons of the TGFBI gene were screened for mutations previously associated with lattice corneal dystrophy as well as novel coding region changes., Results: No mutations were found in the 17 exons of the TGFBI gene. A nucleotide change in exon 6 (651C>G) did not result in a change in the encoded amino acid (Leu217Leu)., Conclusions: In cases of suspected TGFBI corneal dystrophies, genetic testing is a useful tool to confirm the clinical diagnosis. In this case of suspected unilateral lattice corneal dystrophy, screening of the TGFBI gene ruled out the diagnosis, raising the possibility that the corneal changes were related to the coexistent anterior basement membrane dystrophy.

Purpose: Progressive corneal astigmatism occurring at least 10 years after penetrating keratoplasty for keratoconus is a late-phase complication of surgery. This report characterizes this condition in a series of patients from three corneal referral centers in the United States., Methods: Charts were retrospectively reviewed which met the following criteria: penetrating keratoplasty performed for keratoconus at least 10 years ago, keratometry or simulated keratometry from topography as well as manifest refraction recorded at least 6 months after the last suture removal ("baseline"), and an increase in corneal astigmatism of at least three D over baseline recorded at least 5 years later. Patients who had any other corneal or intraocular surgery performed were excluded., Results: Data from 15 patients (11 males and 4 females) who had penetrating keratoplasties performed by 8 different surgeons are included in this descriptive series. Postoperative follow-up averaged 17.27 years (range 11-24 years). The average donor button size was 7.83 mm (range 7.25-8.5 mm). Baseline corneal astigmatism was obtained an average of 5.2 years after penetrating keratoplasty (range 1.5-16 years) and was on average 3.57 +/- 1.8 D (10 with-the-rule [WTR], 3 against-the-rule [ATR], 2 oblique). Corneal astigmatism significantly increased to an average of 11.23 +/- 3.56 D (range 8.00-19.37 D, P < 0.0001) and most astigmatism was regular and WTR (9 WTR, 3 ATR, 3 oblique) 15.3 years (range 10-22 years) after surgery. Inferior steepening on topography was often noted, even those with oblique and ATR axes., Conclusions: High, late-stage, regular astigmatism after penetrating keratoplasty for keratoconus is described in a series of patients occurring at least 10 years after surgery. Possible mechanisms of this progressive astigmatism are recurrence of keratoconus in the graft, progressive corneal thinning of the host cornea, or progressive misalignment of the graft-host interface over time.

We studied oxygen supply to the contact lens covered cornea by means of a complex calculation method. We measured lens thicknesses, both centrally and at a 3mm peripheral location, of a range of optical powers of two different spherical silicone hydrogel contact lens designs (manufactured by Ciba Vision and Bausch & Lomb) and one "traditional" hydrogel. Using the measured values of lens thickness and the nominal oxygen permeabilities of these three plastics, we calculated the oxygen tension level in the tear layer posterior to the contact lens and anterior to the cornea and the oxygen flux through these contact lenses, under both open- and closed-eye conditions. We conclude that variable thicknesses of the silicone hydrogel contact lenses does not significantly affect the oxygen tension in the entrapped tear layer, given their high oxygen diffusion coefficients, under open-eye conditions, and probably only minimally under closed-eye conditions as well.

Purpose: To quantify the complexity involved in fitting contact lenses on the eyes of patients with keratoconus., Methods: The contact lens care of one randomly selected eye each of 38 keratoconus patients was retrospectively analyzed and compared to that of 38 gender and age matched controls. We evaluated the number of diagnostic contact lenses used to establish the initial contact lens order, number of ordered rigid gas permeable (RGP) contact lenses needed to complete the fit, number of office visits during the initial 4 months of care, best spectacle and RGP contact lenses corrected Log MAR visual acuities, complications encountered, and whether or not the patient was successful in contact lens wear., Results: Keratoconic eyes statistically used more diagnostic lenses, more ordered lenses, and more office visits than did normal eyes. Visual acuities improved from an average of 20/40 with spectacles to an average of 20/20 by use of RGP contact lenses in keratoconic eyes. Visions were corrected to 20/20 with both spectacles and contact lenses in control eyes. Sixty nine percent (69%) of keratoconic eyes and 95% of controls were successful in contact lens wear., Conclusions: Contact lens care of keratoconic eyes is more challenging than care of normal eyes because of the need for more diagnostic and ordered contact lenses and the use of more professional time. Keratoconic eyes may suffer more complications than normals during contact lens care, but this does not affect the success rates, and such patients benefit from enhanced visual acuity with RGP contact lenses compared to that achieved with spectacles.

Purpose: To demonstrate the feasibility of contact lens fitting in keratoconus patients with INTACS inserts., Methods: A chart review was conducted of all patients with bilateral keratoconus who were treated with INTACS inserts on one eye and who were subsequently referred for contact lens fitting in a university based contact lens practice between April 2000 and April 2002. The study was a retrospective, non-comparative case series. The uncorrected and best spectacle corrected visual acuity (BSCVA) after INTACS implantation surgery, postoperative best contact lens-corrected visual acuity (BCLVA), number of diagnostic contact lenses used, number of contact lenses ordered within a 4-month follow-up period, contact lens complications encountered, final base curves, final lens powers, and final wearing times were determined., Results: Three keratoconic patients meeting the selection criteria were found through the chart review. Prior to surgery, all patients had uncorrected visual acuity (UCVA) of 2.0 logMAR (counting fingers). This improved to a mean of 0.81+/-0.25 logMAR (20/125-1) after surgery. Mean BSCVA also improved from 0.51+/-0.30 logMAR (20/60-2) to 0.30+/-0.16 logMAR (20/40). The mean postoperative best contact lens-corrected visual acuity was 0.02+/-0.10 logMAR (20/20-1). The number of diagnostic lenses ranged from 1 to 7. The numbers of contact lenses ordered during the 4-month follow up period ranged from 1 to 3. Two eyes were fitted with larger than usual lens designs made of rigid gas-permeable material and one eye was fitted with a toric soft lens. The final lens power ranged from +1.25 to -21.0D with a mean spherical equivalent of -7.46+/-11.89 D. Final wearing times ranged from 2.5 to 12.0h., Conclusion: Fitting contact lenses on keratoconus patients who have INTACS inserts is feasible and has a role in augmenting their vision.

Purpose: To report a case of severe bilateral deep stromal neovascularization and opacification associated with unmonitored contact lens wear., Design: Observational case report., Methods: A 46-year-old woman who had been using hydrogel contact lenses bought on the Internet without a prescription for 5 years was found to have dense, bilateral corneal opacities with deep stromal neovascularization., Results: The patient's contact lenses were found to be tight-fitting. Medical history and serological studies were negative for infectious or rheumatologic causes of interstitial keratitis., Conclusions: The deep stromal neovascularization and the associated corneal opacification are most likely related to the unmonitored contact lens use and the lack of routine eye examinations. We believe it is critical that all contact lens wearers receive professional eye care on a regular basis regardless of where they obtain their contact lens supplies.

Soman, a powerful inhibitor of acetylcholinesterase, causes an array of toxic effects in the central nervous system including convulsions, learning and memory impairments, and, ultimately, death. We report on the protection afforded by postexposure antidotal treatments, combined with pyridostigmine (0.1 mg/kg) pretreatment, against these consequences associated with soman poisoning. Scopolamine (0.1 mg/kg) or caramiphen (10 mg/kg) were administered 5 min after soman (1.2 LD50), whereas TAB (i.e., TMB4, atropine, and benactyzine, 7.5, 3, and 1 mg/kg, respectively) was injected in rats concomitant with the development of toxic signs. Atropine (4 mg/kg) was given to the two former groups at the onset of toxic symptoms. Caramiphen and TAB completely abolished electrographic seizure activity while scopolamine treatment exhibited only partial protection. Additionally, no significant alteration in the density of peripheral benzodiazepine receptors was noted following caramiphen or TAB administration, while scopolamine application resulted in a complex outcome: a portion of the animals demonstrated no change in the number of these sites whereas the others exhibited markedly higher densities. Cognitive functions (i.e., learning and memory processes) evaluated using the Morris water maze improved considerably by the three treatments when compared to soman-injected animals; the following rank order was observed: caramiphen > TAB > scopolamine. Additionally, statistically significant correlations (r = 0.72, r = 0.73) were demonstrated between two learning parameters and [3H]Ro5-4864 binding to brain membrane. These results show that drugs with a pharmacological profile consisting of anticholinergic and antiglutamatergic properties such as caramiphen and TAB, have a substantial potential as postexposure therapies against intoxication by organophosphates.

Purpose: To investigate the relationship between functional phenotype of and the associated human corneal infection., Methods: This was an experimental pilot study of patients presenting with corneal infections at the Jules Stein Eye Institute with presumed infection during the period from 12/30/97 to 9/1/00. Thirteen patients were admitted to the study based on positive identification of the causative pathogen as and patient consent. Data were collected (including bacterial cultures, lens wear schedule and care, gender and age, completed history questionnaire, clinical photographs). Statistical analysis of possible correlations was performed. Phenotypes of were determined, and clinical factors associated with infection were explored., Results: Both invasive and cytotoxic phenotypes of were isolated in equal proportion. Cytotoxic strains and invasive strains were found to be associated with patients younger than 50 years of age and older than 50 years of age, respectively., Conclusions: remains a significant pathogen in corneal infection, especially during contact lens wear. The age of the patient may influence the phenotype of causing infection. Since invasive and cytotoxic strains have different effects on corneal cells, treatment of the infection might require different approaches depending on this phenotype of the causative bacteria.

There are numerous methods designed to monitor brain neuropathologies resulting from a wide arsenal of insults. Regardless of the cause of neuronal death, reactive glial cells always appear at and around the site of degeneration. These cells are distinguished by the exceptional abundance of peripheral benzodiazepine receptors, particularly compared with surrounding neurons. Measuring the binding of specific ligands to these peripheral benzodiazepine receptors offers a unique indirect marker for reliable damage assessment in the CNS and a faithful indicator for the accompanying cognitive deficits.

Background: Cataracts pose a serious threat to the visual system in infants and children, requiring prompt surgical intervention and rehabilitation to optimize visual development. Glaucoma is a serious complication following cataract surgery in infants and can lead to loss of vision. Early diagnosis of glaucoma, however, can be quite challenging in these patients., Case Reports: Three cases are presented in which comeal edema was the initial presenting sign that led to the diagnosis of glaucoma during routine contact lens follow-up examinations for pediatric aphakia., Conclusion: The contact lens practitioner, during the course of management of aphakic infants and children, should always be suspicious of glaucoma as a complication of cataract surgery, and the presenting sign may be corneal edema.