Assessment of differential intraocular pressure response to dexamethasone treatment in perfusion cultured Indian cadaveric eyes.

The purpose of the present study was to assess the differential intraocular pressure response (IOP) to dexamethasone (DEX) treatment at two dose levels (100 or 500 nM) in perfusion cultured Indian cadaveric eyes to investigate glucocorticoid (GC) responsiveness. In a human organ-cultured anterior segment (HOCAS) set-up, the eye pressure was monitored for every 24 h post DEX infusion (100 or 500 nM) or 0.1% ethanol treatment for 7 days after baseline stabilization. The expression of DEX-inducible proteins such as myocilin and fibronectin in HOCAS-TM tissues was assessed by immunostaining. Elevated IOP was observed in 6/16 eyes [Mean ± SEM (mΔIOP): 15.50 ± 1.96 mmHg; 37.5% responders] and 3/15 eyes (Mean ± SEM mΔIOP: 10 ± 0.84 mmHg; 20% responders) in 100 nM and 500 nM dose groups respectively. Elevated IOP in GC responder eyes was substantiated with a significant increase in myocilin (11.8-fold; p = 0.0002) and fibronectin (eightfold; p = 0.04) expression as compared to vehicle-treated eyes by immunofluorescence analysis. This is the first study reporting the GC responsiveness in Indian cadaveric eyes. The observed GC response rate was comparable with the previous studies and hence, this model will enable us to investigate the relationship between differential gene expression and individual GC responsiveness in our population.

Improving eye care in residential aged care facilities using the Residential Ocular Care (ROC) model: study protocol for a multicentered, prospective, customized, and cluster randomized controlled trial in Australia.

BACKGROUND: Older adults in residential aged care facilities have unnecessarily high levels of vision impairment (VI) which are largely treatable or correctable. However, no current comprehensive eye health service model exists in this setting in Australia. We aimed to determine the clinical, person-centered, and economic effectiveness of a novel eye care model, the Residential Ocular Care (ROC). METHODS/DESIGN: This protocol describes a multicentered, prospective, randomized controlled trial. A total of 395 participants with distance vision < 6/12 (0.30 LogMAR) and/or near vision N8 (1.00 M) or worse will be recruited from 38 urban and rural aged care facilities across Victoria, Australia. Aged care facilities will be randomized (1:1) to one of two parallel groups. Participants in the ROC group will receive a comprehensive and tailored eye care pathway that includes, as necessary, refraction and spectacle provision, cataract surgery, low vision rehabilitation, and/or a referral to an ophthalmologist for funded treatment. Usual care participants will be referred for an evaluation to the eye care service associated with the facility or an eye care provider of their choice. The primary outcome will be presenting near and distance vision assessed at the two- and six-month follow-up visits, post baseline. Secondary outcomes will include vision-specific quality of life, mobility, falls, depression, and eye care utilization at two and six months. An incremental cost-effectiveness analysis will also be undertaken. DISCUSSION: The ROC study is the first multicentered, prospective, customized, and cluster randomized controlled trial in Australia to determine the effectiveness of a comprehensive and tailored eye care model for people residing in aged care facilities. Results from this trial will assist health and social care planners in implementing similar innovative models of care for this growing segment of the population in Australia and elsewhere. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry, ACTRN12615000587505 . Registered on 4 June 2015 - retrospectively registered.

Assessment of Startle Response and Its Prepulse Inhibition Using Posturography: Pilot Study.

Purpose. The aim of this study was to evaluate the possibility of using static posturography in the assessment of sensorimotor gating. Subjects and Methods. Fourteen subjects took part in the experiment. The inhibitory mechanisms of startle reflex were used as the measure of sensorimotor gating. It was evoked by a strong acoustic stimulus (106 dB SPL, 40 ms) which was preceded by the weaker similar signal (80 dB SPL, 20 ms). A stabilographic platform was used to measure sensorimotor gating. Results. Results of static posturography show that the postural sway caused by the reaction to a strong acoustic stimulus is significantly smaller when this stimulus is preceded by the signal of lower intensity (prepulse). Such assessment is only possible in eyes open conditions. Conclusions. Static posturography can be simple and effective method used for diagnosis of sensorimotor gating in humans.

Kilovoltage radiosurgery with gold nanoparticles for neovascular age-related macular degeneration (AMD): a Monte Carlo evaluation.

This work uses Monte Carlo radiation transport simulation to assess the potential benefits of gold nanoparticles (AuNP) in the treatment of neovascular age-related macular degeneration with stereotactic radiosurgery. Clinically, a 100 kVp x-ray beam of 4 mm diameter is aimed at the macula to deliver an ablative dose in a single fraction. In the transport model, AuNP accumulated at the bottom of the macula are targeted with a source representative of the clinical beam in order to provide enhanced dose to the diseased macular endothelial cells. It is observed that, because of the AuNP, the dose to the endothelial cells can be significantly enhanced, allowing for greater sparing of optic nerve, retina and other neighboring healthy tissue. For 20 nm diameter AuNP concentration of 32 mg g(-1), which has been shown to be achievable in vivo, a dose enhancement ratio (DER) of 1.97 was found to be possible, which could potentially be increased through appropriate optimization of beam quality and/or AuNP targeting. A significant enhancement in dose is seen in the vicinity of the AuNP layer within 30 µm, peaked at the AuNP-tissue interface. Different angular tilting of the 4 mm beam results in a similar enhancement. The DER inside and in the penumbra of the 4 mm irradiation-field are almost the same while the actual delivered dose is more than one order of magnitude lower outside the field leading to normal tissue sparing. The prescribed dose to macular endothelial cells can be delivered using almost half of the radiation allowing reduction of dose to the neighboring organs such as retina/optic nerve by 49% when compared to a treatment without AuNP.

The assessment of anterior and posterior ocular structures in hyperopic anisometropic amblyopia.

BACKGROUND: The aim of this study was to examine the relationship or differences in ocular structures of amblyopic eyes compared to fellow eyes in children and young adults with hyperopic anisometropic amblyopia. MATERIAL/METHODS: Hyperopic participants with anisometropic amblyopia, defined as the presence of best-corrected visual acuity differences of at least 2 Snellen lines and 1.5 diopters between amblyopic and fellow eyes, were studied. Using the IOL Master, Pentacam Scheimpflug imaging and Spectralis optical coherence tomography, the axial length, corneal curvature, and anterior chamber depth (ACD), as well as the thickness of the cornea, peripapillary retinal nerve fiber layer (RNFL), and macula, were compared between children and young adults and between their amblyopic and fellow eyes. RESULTS: In 53 participants with hyperopic anisometropic amblyopia, there were significant differences in the anterior corneal curvature, ACD and axial length between the amblyopic and fellow eyes of all the patients. The mean central macular thickness in the amblyopic eyes was significantly thicker (P=.001) in the group aged 5 to 12 years; however, this was not the case in the group aged 13 to 42 years. There was no significant difference in average RNFL thickness in either group. CONCLUSIONS: We found significantly greater mean central macular thickness in anisometropic amblyopic eyes among participants aged 5 to 12 years, but not among those who were older. Similarly, the interocular differences in axial length parameters seemed to be related to the central macular thickness differences between the amblyopic and fellow eyes in the younger group.

[Assessment of age-old cataract phacoemulsification influence on the morphometric parameters of eye and intraocular pressure level].

Morphometric parameters, hemodynamic and hydrodynamic of the eye before and after cataract phacoemulsification with IOL implantation were studied. 74 patients (97 eyes) with a cataract at the age of 53-79 years including, 49 women and 25 men were examined. Established: it is advisable to make cataract phacoemulsification with IOL implantation in patients accompanied by increased blood flow in the early stages of cataract development.

Outcomes of a nontransfer protocol for mild traumatic brain injury with abnormal head computed tomography in a rural hospital setting.

OBJECTIVE: This study sought to investigate outcomes after a novel nontransfer protocol for mild traumatic brain injuries patients with small intracranial hemorrhage (ICH) in a rural trauma center without neurosurgical capabilities. METHODS: This was a retrospective cohort study. In 2007, a nontransfer protocol was implemented at a Level III Trauma Center. It included adult patients from April 2007 through December 2012 with mild traumatic brain injury (mTBI) (Glasgow Coma Scale score 13 to 15) and computed tomography (CT) showing small ICH and no coagulopathy. The following ICHs were allowed: 1) minimal or small traumatic subarachnoid hemorrhage, 2) punctuate or minimal superficial cerebral contusion, 3) punctuate or minimal intraparenchymal hemorrhage, or 4) very small subdural hemorrhage (SDH) without mass effect (a very thin smear SDH along the tentorium or falx). CT scans were reviewed by the on-call neurosurgeon at an affiliated Level I Trauma Center, and consensus was obtained on the suitability for nontransfer. RESULTS: A total of 76 patients were included. The median hospital length of stay was 1 day (interquartile range = 1 day). No patient required a neurosurgical intervention or postadmission transfer to a Level I facility. There were no in-hospital deaths, and all patients were discharged with stable head CTs and in good neurologic condition. Two patients were readmitted for nonprotocol-related reasons: 1 acute-on-chronic SDH 6 weeks postdischarge, and 1 visual eye change with normal CT 2 days postdischarge. CONCLUSIONS: Our 6-year study corroborates the low neurosurgical rate reported in the literature for mTBI with small ICH. Nontransfer protocols may lead to a more efficient use of hospital resources while providing safe, effective and economical health care.

[Ocular blood flow assessment in normal subjects and in patients with hyperglycemia based on the results of ultrasonic examination in experiment].

Scheme of ocular blood flow in rats was developed and main blood flow parameters were studied using color Doppler mapping, energetic mapping and impulse Doppler ultrasonography. Features of ocular blood flow changes are revealed in experimental model of streptozotocin induced diabetes mellitus during 12 months of follow-up. Inferior ophthalmic artery showed the most significant changes. Decrease of all parameters of blood flow velocity was found in central retinal artery, central retinal vein and in posterior long ciliary arteries. Increase of resistance index was observed during the entire follow-up period. Revealed data show development of hemodynamic changes before clinical signs of retina damage ip rats with hyperglycemia.

An assessment of the ocular safety of excipient maleic acid following intravitreal injection in rabbits.

Maleic acid was formulated in 0.7% saline and injected intravitreally in rabbits in order to evaluate ocular safety and tolerability. Maleic acid was formulated within a narrow pH range (2-3), administered in a fixed volume (100 µl), and concentrations ranged from 0.00 to 2.00 mg/eye (0.00 to 12.30 mM vitreous). Ocular evaluations were conducted at 2, 4, and 8 days post injection. Ocular irritation responses were observed at doses from 0.50 mg/eye (3.07 mM vitreous) to 2.00 mg/eye (12.30 mM vitreous) and included conjunctival redness and scleral swelling. Chemosis was observed at 2.00 mg/eye (12.30 mM vitreous). Funduscopic evaluations revealed enlarged retinal blood vessels and optic disk swelling at doses ≥1.50 mg/eye (9.22 mM vitreous), retinal folds and retinal discoloration at 2.00 mg/eye (12.30 mM vitreous). Histopathologic evaluations on days 4 and 8 post injection revealed retinal degeneration at doses ≥1.0 mg/eye (6.15 mM vitreous), conjunctival inflammation at doses ≥1.5 mg/eye (9.22 mM vitreous), and retinal pigment epithelial hypertrophy, optic nerve demyelination, anterior chamber fluid, and conjunctival fibrosis at 2.00 mg/eye (12.30 mM vitreous) maleic acid. The data suggest that maleic acid formulations at ≥1.00 mg/eye (6.15 mM vitreous) were not suitable for intraocular indications.

Understanding dry eye disease: a managed care perspective.

Dry eye disease (DED) is a multifactorial disorder that results in eye discomfort, visual disturbance, and often ocular surface damage. This supplement to The American Journal of Managed Care discusses the prevalence of DED and the economic burden associated with DED. The etiology and pathophysiology of DED will also be discussed, including disease progression and impact on the patient's quality of life. With greater understanding of the pathophysiology of DED, there are numerous available therapies/strategies for the management of the disorder, ranging from artificial tear substitutes, anti-inflammatory agents, secretagogues, punctal plugs, and systemic immunosuppressives, to surgery. This activity will aim to provide managed healthcare professionals with an understanding of when and how to use these different strategies to reduce morbidity and prevent complications.

Assessment of targeting accuracy of a low-energy stereotactic radiosurgery treatment for age-related macular degeneration.

Age-related macular degeneration (AMD), a leading cause of blindness in the United States, is a neovascular disease that may be controlled with radiation therapy. Early patient outcomes of external beam radiotherapy, however, have been mixed. Recently, a novel multimodality treatment was developed, comprising external beam radiotherapy and concomitant treatment with a vascular endothelial growth factor inhibitor. The radiotherapy arm is performed by stereotactic radiosurgery, delivering a 16 Gy dose in the macula (clinical target volume, CTV) using three external low-energy x-ray fields while adequately sparing normal tissues. The purpose of our study was to test the sensitivity of the delivery of the prescribed dose in the CTV using this technique and of the adequate sparing of normal tissues to all plausible variations in the position and gaze angle of the eye. Using Monte Carlo simulations of a 16 Gy treatment, we varied the gaze angle by ±5° in the polar and azimuthal directions, the linear displacement of the eye ±1 mm in all orthogonal directions, and observed the union of the three fields on the posterior wall of spheres concentric with the eye that had diameters between 20 and 28 mm. In all cases, the dose in the CTV fluctuated <6%, the maximum dose in the sclera was <20 Gy, the dose in the optic disc, optic nerve, lens and cornea were <0.7 Gy and the three-field junction was adequately preserved. The results of this study provide strong evidence that for plausible variations in the position of the eye during treatment, either by the setup error or intrafraction motion, the prescribed dose will be delivered to the CTV and the dose in structures at risk will be kept far below tolerance doses.

The chronic effects of sulfur mustard exposure.

Whilst the acute effects of sulfur mustard have been relatively well characterised, the chronic effects of short term but significant exposures are still evolving. The approximately 30,000 Iranian victims of CW exposure from the 1980 to 1988 Iran-Iraq war who are currently being followed form a key population who are now 20 years post-exposure. The key chronic findings in this population reflect the common acute effects of sulfur mustard, and are related to the skin, eye and respiratory system. Excluding pruritus, skin changes appear to settle. Eye symptoms are slowly progressive, however a severe, rapid onset form of keratitis is seen to develop in a number of patients after a latent period of 15-20 years. The respiratory tract also shows progressive deterioration, with bronchiolitis obliterans now being considered the main pathological feature of "mustard lung". In addition, there are other potential effects of sulfur mustard exposure which become evident only in the longer term and which are being investigated, including the development of cancer, immunological and neuropsychiatric changes, and reproductive effects. Finally, a chronic effect of sulfur mustard exposure that is now becoming apparent is the wider long-term social and economic effects of these illnesses on individuals and their families.

Non-invasive biometric assessment of ocular rigidity in glaucoma patients and controls.

PURPOSE: To determine in vivo whether a pharmacologically induced change in intraocular pressure (IOP) leads to measurable changes in axial eye length and whether there is a difference between glaucoma patients and control subjects. METHODS: 42 subjects (19 patients with primary open angle glaucoma and 23 control patients matched for age and gender) underwent axial eye length measurement using partial coherence laser interferometry and measurement of IOP using dynamic contour tonometry before and 2 h after oral intake of 500 mg acetazolamide. Student's t-test was used to compare differences in the means. RESULTS: An identical drop in IOP was induced in both the glaucoma (mean+/-SEM: 2.90+/-0.44 mmHg, n=19) and the control group (mean+/-SEM: 3.17+/-0.32 mmHg, n=23). The change in axial eye length was significantly smaller (P=0.026) in the glaucoma group (mean+/-SEM: -14.2+/-3.2 microm, n=19) compared with the control group (mean+/-SEM: -23.0+/-2.98 microm, n=23). CONCLUSIONS: Our results strongly suggest that the ocular rigidity is increased in patients with established glaucoma in comparison to control subjects. Ocular rigidity could play a role in the pathogenesis and pathophysiology of glaucoma. Determination of ocular rigidity could be helpful in detection of glaucoma.

[Eyeball structure changes in high myopic patients and their significance for forensic assessment].

There are irreversible eyeball structural changes in high myopic patients. These changes include axial length, corneal radius, anterior chamber depth, fundus degeneration, macula thickness, etc. There is a close relationship between the damage degree of visual function and these changes. The incidence of complications, such as vitreous opacity, posterior vitreous detachment, cataract, glaucoma, posterior staphyloma and retina detachment, is also highly related to the myopia diopter. More and more researches have indicated that the myopia diopter and the level of visual function are affected by multiple factors. It is promising to detect all of these changes by different kinds of methods, and to assess visual function through these changes. By clarifying these changes, it is also useful to distinguish traumatic damage from disease to provide evidence for forensic assessment of eye injuries.

Ocular effects of exposure to industrial chemicals: clinical management and proteomic approaches to damage assessment.

Industrial chemicals in a variety of applications are often found in highly populated areas and their presence carries risks. The threat of serious consequences from inadvertent or intentional events involving hazardous chemicals is a possibility. Extremism and/or other illicit activities pose environmental threats from chemical exposures. We present here a review of the threat of ocular injury in small-and large-scale chemical releases and discuss mechanisms of damage and repair to the eyes. The emerging field of proteomics has been described in relation to its potential role in the assessment of ocular changes following chemical exposures and management of ocular trauma.

Las lecciones derivadas del ASA Closed Claims Project (ASACCP). Proyecto de la ASA acerca de las razones que promovieron demandas contra anestesiólogos cuyos casos estuviesen ya archivados. 5a. parte: Pérdida de la visión y otras complicaciones oculares del postoperatorio / Lessons learned from the ASA Closed Claims Project (ASACCP). ASA project about the reasons for wich claims against anesthesiologists were renewed in cases that had already been closed. Part 5: Loss of vision and other postoperative ocular complications

A pesar de ser la ceguera postoperatoria una complicación rara en la cual la neuropatía isquémica del nervio óptico parecer ser la causa predominante, ella se habría incrementado en los últimos tiempos, por lo menos en lo que respecta a la frecuencia con que aparece descripta en la literatura médica. El ASACCP, luego de analizar más de 5.800 expedientes cuyos juicios por presunta mala praxis estaban concluídos, descubrió que solamente el 3 por ciento de las demandas estaban relacionadas con amaurosis postoperatoria en cirugías no oftalmológicas. A partir de este estudio, y con el objeto de ahondar más en las causas de una complicación tan grave, en junio de 1999 la ASA formó una comisión especial dentro del ASACCP (ASA Closed Claims Proyect), el Postoperative Visual Loss Registry (PVLR) que elaboró un formulario para ser llenado, en forma anónima, por los miembros de la entidad cuando se enfrentan con un caso de lesión ocular postoperatoria. En este trabajo se analizan las causas dela ceguera postoperatoria y se describe su aparición durante distintos procedimientos quirúrgicos y anestésicos.

Use of preoperative assessment of positionally induced cyclotorsion: a video-oculographic study.

PURPOSE: Positionally induced cyclotorsion could be an important factor concerning correction of astigmatism in refractive surgery. The method of binocular three dimensional infrared video-oculography (3D-VOG) was used to determine a possible influence of body position on cyclotorsion. METHODS: 38 eyes (19 healthy subjects, median value of age 25.5) with normal binocular vision were examined using 3D-VOG. This method records ocular motions and positions of both eyes simultaneously in the x, y, and z axis. Cycloposition of the eyes was recorded first in a seated position (both eyes open, test 1), then in a supine position (right eye closed, test 2), occlusion of both eyes (test 3), both eyes open (test 4). Cyclovergence was calculated as the difference between the right and the left eye positions. RESULTS: The range of cyclotorsion of the right and left eye in all four tests was between 1.13 degrees excyclotorsion and 0.34 degrees incyclotorsion. There was no statistically significant difference of the median values for torsion for the four test situations. Concerning the influence of body position on cyclotorsion, a statistically significant difference between the different test positions and settings did not exist. Median values for right/left torsion/cyclovergence were: 0.17/0.04/0.02 (test 1), -0.31/-0.71/-0.16 (test 2), -1.09/-0.60/0.82 (test 3), 0.28/0.28/-0.82 (test 4). CONCLUSIONS: Cyclotorsion does not significantly change between seated and supine position in subjects with normal binocular vision and stable fixation. In these subjects, an erroneous refractive surgery due to incorrect measurement of the axis of astigmatism in the seated position and performing the refractive surgery in the supine position, is very unlikely.

Color Doppler assessment of normal ocular blood flow.

The purpose of this study was to determine the role of CDI in the assessment of normal ocular vasculature. Color and pulsed Doppler examinations were performed in 20 healthy subjects. The principal orbital vessels were detected: ophthalmic, central retinal, lacrimal, and posterior ciliary arteries and, in a small percentage, superior ophthalmic, central retinal, and vortex veins; blood flow of arterial vessels was studied by measuring TAV, St, PS, MD, ED, PI, and RI; the morphology of the spectral waveform also was investigated. Our results suggest that duplex color Doppler may be of value in ocular vasculature examination.

Assessment of the nervous system.

This article describes the examination of the neurologic and ophthalmic systems in ruminants. Neuroanatomy with respect to lesion localization is reviewed. Pertinent age and species differences are addressed. The practical aspects of assessing the neurologic system are stressed, and the reader is directed to other sources of information for assistance in determining the differential diagnosis and therapy of neurologic disease.

The use of laboratory animals in toxicology: an ophthalmoscopic assessment.

In a recent text by Grant (3), approximately 2,800 substances are listed as having some type of untoward effect on ocular tissue. The kinds of substances that may cause toxic damage/effects range from carbolic acid (2) to oxygen (1). It is the purpose of this communication to briefly review ocular toxicology as investigated in laboratory animals.