To validate changes in intraocular pressure (IOP) after phacoemulsification with intraocular lens (IOL) implantation without pressure-lowering surgery in previously unoperated eyes of normal and ...glaucoma patients.
University Eye Clinic, Otto-von-Guericke-University, Magdeburg, Germany.
Cohort study.
The IOP in both eyes of patients was determined by Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) 1 to 2 days before and after uneventful unilateral surgery. Central corneal thickness was used to correct raw GAT readings.
Of the 50 patients having unilateral phacoemulsification, 29 had had cataract extraction in the contralateral eye. The mean baseline IOP was 17.4 ± 4.4 mm Hg (GAT) and 16.6 ± 2.9 mm Hg (DCT). Postoperatively, the GAT IOP decreased to 16.4 ± 6.5 mm Hg and the DCT IOP increased slightly to 17.1 ± 4.1 mm Hg. The mean tonometer difference (ΔIOP = GAT - DCT) amounted to ΔIOP(pre) = +0.75 ± 2.69 mm Hg in phakic eyes and ΔIOP(post) = -0.70 ± 3.76 mm Hg in pseudophakic eyes (P=.0011). Consistent results were found in pairs of phakic eyes and pseudophakic eyes (mean IOP 18.0 ± 4.8 mm Hg GAT and 17.0 ± 3.3 mm Hg DCT). In fellow eyes, the mean GAT reading was 13.4 ± 4.4 mm Hg and the mean DCT value, 14.8 ± 2.4 mm Hg. ΔIOP(phakic) was +1.04 ± 2.75 mm Hg and ΔIOP(pseudophakic) was -1.48 ± 2.78 mm Hg (P=.00000021).
The GAT IOP readings in pseudophakic eyes seemed to be falsely low. Hence, special attention in the screening, diagnosis, and management of glaucoma is necessary.
In this study, we hypothesize that the worldwide distribution of cognitive ability is determined in part by variation in the intensity of infectious diseases. From an energetics standpoint, a ...developing human will have difficulty building a brain and fighting off infectious diseases at the same time, as both are very metabolically costly tasks. Using three measures of average national intelligence quotient (IQ), we found that the zero-order correlation between average IQ and parasite stress ranges from r = −0.76 to r = −0.82 (p < 0.0001). These correlations are robust worldwide, as well as within five of six world regions. Infectious disease remains the most powerful predictor of average national IQ when temperature, distance from Africa, gross domestic product per capita and several measures of education are controlled for. These findings suggest that the Flynn effect may be caused in part by the decrease in the intensity of infectious diseases as nations develop.
We present novel clinical observations on negative dysphotopsia (ND) in eyes that have undergone cataract surgery. In the past, shadow effects were alleged to be located in the far peripheral ...temporal visual field 50° to 100° away from the optical axis. In a small series of eight patients we found evidence of photic effects, described by the patients as shadows in the periphery that were objectively located much more centrally. In all cases, we could find an association of these phenomena with the blind spot. We hypothesize that the memory effect of the blind spot which is dislocated and changed in magnification due to replacement of the crystalline lens could be one determinant for pseudophakic ND. The scotoma of the optic nerve head and the main arteries and veins of the phakic eye are displaced in the pseudophakic eye depending on the specific characteristics and position of the intraocular lens within the eye.
Epidemiologic autopsy studies show mixed Alzheimer's disease (AD)/vascular pathology in many patients. Moreover, clinical research shows that it is not uncommon for AD and vascular dementia (VaD) ...patients to be equally impaired on memory, executive, or other neurocognitive tests. However, this clinical heterogeneity has not been incorporated into the new diagnostic criteria for AD (Dubois et al., 2010; McKhann et al., 2011).
The current research applied Latent Class Analysis (LCA) to a protocol of six neuropsychological parameters to identify phenotypic subtypes from a large group of AD/VaD participants. Follow-up analyses examined difference between groups on neuroradiological parameters and neuropsychological measures of process and errors.
223 AD/VaD patients were administered a comprehensive neuropsychological protocol. Measures of whole brain and hippocampal volume were available for a portion of the sample (n = 76).
LCA identified four distinct groups: moderate/mixed dementia (n = 54; 24.21%), mild/mixed dementia (n = 91; 40.80%); dysexecutive (n = 49, 21.97%), and amnestic (n = 29, 13.00%). Follow-up analyses comparing the groups on neuropsychological process and error scores showed that the dysexecutive group exhibited difficulty sustaining mental set. The moderate/mixed group evidenced pronounced impairment on tests of lexical retrieval/naming along with significant amnesia. Amnestic patients also presented with gross amnesia, but showed relative sparing on other neuropsychological measures. Mild/mixed patients exhibited milder memory deficits that were intermediary between the amnestic and moderate/mixed groups.
There are distinct neuropsychological profiles in patients independent of clinical diagnosis, suggesting that the two are not wholly separate and that this information should be integrated into new AD diagnostic paradigms.
Abstract
Purpose: To determine the interaction between corneal topographic and tomographic parameters and dry eye syndrome (DES) in keratoconus (KC) patients.
Methods: Seventy-seven eyes of 49 ...patients with KC (age 34.4 ± 11.6 years) were enrolled in this study. In these 77 eyes we recorded surface regularity index (SRI), surface asymmetry index (SAI) and Klyce/Maeda KC index (KCI) using the Topographic Modeling System (TMS-5, Tomey, Tennenlohe, Germany), Index of Surface Variance (ISV), Index of Vertical Asymmetry (IVA), KC Index (KI), Center KC Index (CKI), Index of Height Asymmetry (IHA) and Index of Height Decentration (IHD) using Pentacam (Pentacam HR, Oculus, Germany). Patients were subdivided into mild (grade 1-2) and severe stage (grade 3-4) KC groups according to Pentacam grading.
To analyse tear film parameters we assessed in 77 KC eyes McMonnies questionnaire, Schirmer test and break-up time and in 26 eyes (10 eyes with mild KC, 16 eyes with severe KC) high-speed videokeratoscopy (during interblinking interval) using a novel commercially not available system (Tear Inspect). With Tear Inspect the analysed tear film parameters were (1) time of first irregularities of Placido rings and (2) time of eyelid closure. Patients were also subdivided into McMonnies questionnaire positive and negative groups.
Results: We did not find significant difference between patients with mild and severe KC in any of the examined tear film parameters (p > 0.66). There was no significant difference in SRI, SAI, KCI, ISV, IVA, KI, CKI, IHA and IHD in McMonnies test positive and negative KC patients (p > 0.07). There was no correlation between SRI, SAI, KCI, ISV, IVA, KI, CKI, IHA and IHD and any of the examined tear film parameters (without high-speed videokeratoscopy) neither in 77 KC patients nor in mild or severe KC eyes (r < 0.3).
Conclusions: There is no interaction between DES and topographic/tomographic changes in KC-patients.
The metaphase-to-anaphase I transition is a key step in the completion of meiosis I. In mouse oocytes, competence to exit
metaphase I (MI) is developmentally regulated and typically not acquired ...until the preovulatory stage. The possible role of
protein kinase C (PKC) in regulating this critical transition was assessed in both normal oocytes isolated from small antral
follicles (18-day-old B6SJLF1 mice), which have not yet developed the capacity to progress to metaphase II (MII), and also
oocytes defective in their ability to exit MI despite development to the preovulatory stage (24-day-old CX8 recombinant inbred
strains). In both systems, transient suppression of endogenous PKC activity by treatment with a PKC-specific inhibitor, bisindolylmaleimide
I (BIM), promoted the onset of anaphase I in a dose-dependent manner, while activation of PKC with the phorbol ester TPA blocked
progression to MII. Following a 2-h incubation with BIM, the majority of oocytes progressed to, and arrested at, MII. The
resulting MII oocytes were fertilizable in vitro, showing similar cleavage and blastocyst development rates between BIM treated
and untreated controls. Transferred embryos resulted in the development of pups to term in both groups. These data demonstrate
that PKC plays an important role in regulating the onset of anaphase I in mouse oocytes. Moreover, it is concluded that oocytes
isolated from small antral follicles become blocked at MI due to a PKC-mediated signal, suggesting that acquisition of competence
to complete meiosis I involves, in part, the control of PKC activity. Similarly, failure to regulate PKC activity at the preovulatory
stage likely promotes arrest at MI.
The Mouse Genome Database (MGD) is the community database resource for the laboratory mouse, a key model organism for interpreting the human genome and for understanding human biology and disease ...(http://www.informatics.jax.org). MGD provides standard nomenclature and consensus map positions for mouse genes and genetic markers; it provides a curated set of mammalian homology records, user-defined chromosomal maps, experimental data sets and the definitive mouse 'gene to sequence' reference set for the research community. The integration and standardization of these data sets facilitates the transition between mouse DNA sequence, gene and phenotype annotations. A recent focus on allele and phenotype representations enhances the ability of MGD to organize and present data for exploring the relationship between genotype and phenotype. This link between the genome and the biology of the mouse is especially important as phenotype information grows from large mutagenesis projects and genotype information grows from large-scale sequencing projects.
Purpose: To provide a mathematical calculation scheme for customized intraocular lens (IOL) design based on high resolution anterior segment optical coherence tomography (AS-OCT) of anterior eye ...segment and axial length data.
Material and Methods: We use the corneal and anterior segment data from the high resolution AS-OCT and the axial length data from the IOLMaster to create a pseudophakic eye model. An inverse calculation algorithm for the IOL back surface optimization is introduced. We employ free form surface representation (bi-cubic spline) for the corneal and IOL surface. The merit of this strategy is demonstrated by comparing with a standard spherical model and quadratic function. Four models are calculated: (1) quadratic cornea + quadratic IOL; (2) spline cornea + quadratic IOL; (3) spline cornea + spline IOL; and (4) spherical cornea + spherical IOL. The IOL optimization process for the pseudophakic eye is performed by numerical ray-tracing method within a 6-mm zone. The spot diagram on the fovea (forward ray-tracing) and wavefront at the spectacle plane (backward ray-tracing) are compared for different models respectively.
Results: The models with quadratic (1) or spline (3) surface representation showed superior image performance than the spherical model 4. The residual wavefront errors (peak to valley) of models 1, 2, and 3 are below one micron scale. Model 4 showed max wavefront error of about 15 µm peak to valley. However, the combination of quadratic best fit IOL with the free form cornea (model 2) showed one magnitude smaller wavefront error than the spherical representation of both surfaces (model 3). This results from higher order terms in cornea height profile.
Conclusions: A four-surface eye model using a numerical ray-tracing method is proposed for customized IOL calculation. High resolution OCT data can be used as a sufficient base for a customized IOL characterization.
PDF
