Analysis of corneal tomography in select Black and LatinX children.

PURPOSE: Keratoconus (KC) is a bilateral and often asymmetric disease which can progress to corneal thinning and protrusion. Keratoconus in children appears to be more aggressive than in adults. Research on pediatric keratoconus is limited, and treatments rely on research and experience in adult populations. The current study aimed to provide an analysis on the distribution of the corneal tomography measurements in an underserved, Black and LatinX, primarily low-income pediatric population. METHODS: This was a prospective study approved by the Illinois College of Optometry's IRB. A total of 2133 children, presented to a school-based vision clinic within the Chicago Public Schools, were included in the analysis and were classified into three age groups: 3-6 years, 7-12 years, and 13-18 years. Four specific tomography measurements were obtained from the Pentacam (BAD Final D, ART-Max, I-S Ratio, and Thinnest Point Asymmetry). RESULTS: The mean front corneal astigmatism of the study cohort was -1.39D ± 1.45. Tomography indices means were 0.95 ± 0.74 for BAD Final D, 457.34 ± 94.83 for ART-Max, 0.01 ± 0.68 for I-S ratio, and 9.60 ± 25.55 for Thinnest Point Asymmetry. A statistically significant difference was observed among age groups for BAD Final D (p < 0.001), ART-Max (p < 0.001) and Thinnest Point Asymmetry (p = 0.006). CONCLUSION: This study provided the first set of normative data for a pediatric population on the four tomography measurements, offering a reference for potential diagnosis of keratoconus for Black and LatinX children. Further study could include evaluation of additional races along with a comparison with the adult data, which will provide guidance on evaluating the current keratoconus diagnosis criteria to aid early diagnosis of keratoconus in the pediatric population.

Impact of intravenous thrombolysis and emergent carotid stenting on reperfusion and clinical outcomes in patients with acute stroke with tandem lesion treated with thrombectomy: a collaborative pooled analysis.

BACKGROUND AND PURPOSE: Tandem anterior circulation lesions in the setting of acute ischemic stroke (AIS) are a complex endovascular situation that has not been specifically addressed in trials. We determined the predictors of successful reperfusion and good clinical outcome at 90 days after mechanical thrombectomy (MT) in patients with AIS with tandem lesions in a pooled collaborative study. METHODS: This was a retrospective analysis of consecutive patients presenting to 18 comprehensive stroke centers with AIS due to tandem lesion of the anterior circulation who underwent MT. RESULTS: A total of 395 patients were included. Successful reperfusion (modified thrombolysis in cerebral infarction score 2b-3) was achieved in 76.7%. At 90 days, 52.2% achieved a good outcome (modified Rankin Scale score 0-2), 13.8% suffered a parenchymal hematoma and 13.2% were dead. Lower National Institutes of Health Stroke Scale score [odds ratio (OR), 1.26; 95% confidence intervals (CI), 1.07-1.48, P = 0.004], Alberta Stroke Program Early CT Score ≥7 (OR, 2.00; 95% CI, 1.07-3.43, P = 0.011), intravenous thrombolysis (OR, 1.47; 95% CI, 1.01-2.12, P = 0.042) and stenting of the extracranial carotid lesion (OR, 1.63; 95% CI, 1.04-2;53, P = 0.030) were independently associated with successful reperfusion. Lower age (OR, 1.58; 95% CI, 1.26-1.97, P < 0.001), absence of hypercholesterolemia (OR, 1.77; 95% CI, 1.10-2.84, P = 0.018), lower National Institutes of Health Stroke Scale scores (OR, 2.04; 95% CI, 1.53-2.72, P < 0.001), Alberta Stroke Program Early CT Score ≥7 (OR, 2.75; 95% CI, 1.24-6.10, P = 0.013) and proximal middle cerebral artery occlusion (OR, 1.59; 95% CI, 1.03-2.44, P = 0.035) independently predicted a good 90-day outcome. CONCLUSIONS: Intravenous thrombolysis and emergent stenting of the extracranial carotid lesion were predictors of a successful reperfusion after MT of patients with AIS with tandem lesion of the anterior circulation.

Prospective study of lotrafilcon B lenses comparing 2 versus 4 weeks of wear for objective and subjective measures of health, comfort, and vision.

OBJECTIVE: To examine potential changes in comfort, ocular health, and vision between 2 weeks and 1 month for wearers of lotrafilcon B lenses. METHODS: Up to 120 current wearers of lotrafilcon B lenses were recruited to wear a new pair of lenses for 1 month, using their habitual lens care system. Subjective ratings, biomicroscopy scores, visual acuity, and lens assessments were recorded at 2 weeks and at 1 month. In addition, participants responded to 4 Likert-type statements regarding comfort and vision after the full month of wear. RESULTS: No significant differences were noted in biomicroscopy scores between 2 weeks and 1 month. Noninferiority from 2 weeks to 1 month was established for subjective ratings of visual clarity (P=0.003; n=112) and ocular redness (P<0.001; n=112); the other 7 subjective ratings (for comfort, dryness, etc.) decreased less than 1 unit on 10-point scales. Significant majorities of respondents (all P<0.001 vs. 50%) agreed or strongly agreed that the lenses provided excellent comfort (83.5% of respondents) and clear vision (83.5%) throughout the month and that comfort (71.5%) and vision (77.9%) were the same at the end of the month as at the beginning of the month. Two adverse events occurred during the trial. Both were asymptomatic and considered clinically insignificant. CONCLUSIONS: Significant majorities of patients agreed that the lenses provided consistent comfort and vision throughout the month. Most wearers of lotrafilcon B lenses did not perceive substantial deteriorations in comfort or vision over the recommended wearing interval. Outcomes support monthly replacement of these lenses.

Mechanisms for LEPR-mediated regulation of leptin expression in brown and white adipocytes in rat pups.

To investigate the underlying mechanisms for leptin receptor (LEPR)-mediated regulation of leptin gene (Lep) expression in brown (BAT) and white (WAT) adipose tissue and resultant effects on plasma leptin concentrations (plasma-LEP), we examined effects of sympathetic nervous system (SNS) activity, caloric balance, and body fat content on leptin mRNA levels in BAT and WAT in 10-day-old rat pups segregating for Lepr(fa). In mother-reared pups, Lep mRNA levels were fa/fa > +/fa = +/+ in BAT and was fa/fa > +/fa > +/+ in WAT. The genotype effects on Lep expression in BAT and plasma-LEP were virtually eliminated when the differences in SNS activity between fa/fa and +/fa pups were equalized by artificial rearing of pups under thermoneutral conditions with or without oral norepinephrine (NE) administration. NE administration alone had little effect on the Lepr(fa)-dependent stratification of Lep expression in WAT. BAT-Lep mRNA was the main determinant of plasma-LEP. Metabolic rate, a surrogate indicator of SNS activity, explained 87% of the variation in BAT-Lep mRNA (R(2) = 0.93), whereas caloric balance (40%) and body fat mass (6%) accounted for most of the variation in WAT-Lep mRNA (R(2) = 0.53). We conclude that feedback regulation of Lep expression in BAT is primarily via central nervous system-mediated effects of leptin on SNS activity, whereas the control of leptin expression in WAT is more likely via mechanisms not directly dependent on SNS activity.

Leptin responsiveness of juvenile rats: proof of leptin function within the physiological range.

To bridge the gap between studies demonstrating leptin's role in protecting fat stores when food is scarce and other studies demonstrating the effects of treatment with leptin at doses that increase plasma levels to values found in overfed animals, we investigated whether leptin serves an adipostatic function within the normal range of free-feeding lean animals, i.e. within the very small range of endogenous plasma levels at which no leptin resistance occurs. For this purpose we applied recombinant leptin via mini-osmotic pumps to rats between 15 and 24 days of age and between 25 and 34 days of age and studied its dose-dependent effects on body mass and fat mass at plasma leptin concentrations extending down to the normal levels in lean animals. Using percentage change of fat mass (relative to that of saline-treated littermates) as the measure, a linear dose-response curve was found up to doses of 2 microg g(-1) day(-1), corresponding to plasma leptin concentrations between the normal physiological range and 50 ng ml(-1). In 15- to 24-day-old animals, analysis of the correlation (r = -0.89) between individual plasma concentrations and the corresponding leptin-induced changes of body fat content for a range extending down towards zero (i.e. towards the average fat content of the controls) yielded a zero value of 3.1 ng ml(-1), which was within the 2-4 ng ml(-1) range of plasma leptin concentrations found in the control pups. Likewise, regression analysis for the data from the 25- to 34-day-old pups (r = -0.88), for which the control range was 1-3 ng ml(-1), yielded a zero value of 1.9 ng ml(-1). We conclude that normal plasma leptin levels represent an adipostatic signal. Steady-state levels of plasma leptin in free-feeding lean animals thus provide a signal not only for protecting sufficiency but also for limiting increases of body fat stores.

Mutation in the leptin receptor (Leprfa) causes fat-storage-independent hyperleptinaemia in neonatal rats.

The plasma leptin concentration adjusted for fat mass is affected by mutant gene dosage in older animals segregating for Leprfa. Because the plasma of neonatal rats contains leptin, although their adipocytes contain virtually no triglyceride, we determined whether mutation dose-dependent differences in plasma leptin concentration exist before the postnatal onset of triglyceride storage. Plasma samples were obtained 10 min after birth of each rat pup and leptin concentration determined by radioimmunoassay. Plasma leptin in homozygous wild-type (+/+) pups was 1.6 +/- 0.2 ng/ml (n = 20) and 2.4 +/- 0.2 ng/ml in +/fa (n = 32) littermates (least-square means +/- SE, P < 0.05, two-way ANOVA with litter and genotype as factors). The corresponding values for +/fa (n = 21) and fa/fa (n = 15) littermates were 2.4 +/- 0.2 and, 4.0 +/- 0.3 ng/ml respectively (P < 0.001). Leprfa gene dose-dependent elevations in plasma leptin are, therefore, present at birth and constitute the only Leprfa-related phenotypic trait presently known to precede the onset of increased fat storage.

Leptin responsiveness and gene dosage for leptin receptor mutation (fa) in newborn rats.

To determine the degree to which the leptin receptor mutation (fa) influences the responsiveness to leptin during the first postnatal week, we injected recombinant leptin (600 pmol. g-1. day-1 sc from day 1 to day 7) into wild-type (+/+), heterozygous (+/fa), and fatty (fa/fa) rat pups. Growth and final body fat content of these leptin-treated pups were compared with those of saline-treated littermates of the same genotype. The body mass of the leptin-treated +/+ pups, but not that of the +/fa and fa/fa pups, increased more slowly than that of their respective controls, and fat content at day 7 was reduced by 37% in +/+ pups, by 22% in +/fa pups, but not at all in fa/fa pups. Plasma leptin remained excessively high throughout the day under this treatment, but a 30-fold lower leptin dose, causing only moderate changes of plasma leptin, still reduced the body fat of +/+ pups significantly. We conclude that leptin participates in the control of even the earliest stages of fat deposition and that the response to supraphysiological doses of leptin is markedly reduced in 1-wk-old pups with one fa allele and absent in pups with two fa alleles.

Circumscribed posterior keratoconus.

BACKGROUND: Posterior keratoconus is characterized by an internal protrusion of the posterior corneal surface and associated localized or diffuse stromal thinning. Two cases of circumscribed (localized) posterior keratoconus are presented that are representative of the spectrum of the anomaly. CONCLUSIONS: The clinical and histological appearance of posterior keratoconus and its differential diagnosis from other corneal ectasias and developmental anomalies are reviewed to enable the eye care practitioner to better diagnose and manage this rare anterior segment disorder.

[The predictive value of the GRF-stimulation test]. / Die Aussagekraft des GRF-Stimulationstests.

48 patients between one and seventeen years of age were stimulated with GRF (1-29) NH2. Seventeen of them showed a constitutional delay in growth and puberty, twenty-three suffered from growth-hormone deficiency (GHD) and eight had a suspected GHD as a result of pharmacological tests. Although the results demonstrate a high specificity for GH release in children with constitutional delay of growth and patients with functioning hypophyseal gland, the sensitivity for diagnosis of GHD was poor. The majority of GHD patients suffer from hypothalamic disorders and therefore respond to GRF. In conclusion, the GRF-stimulation test may be sufficient for differentiation of hypophyseal or hypothalamic disorders. However, GRF-stimulation test shows too many false positive results in hypothalamic growth disorders and therefore is not recommended for diagnosis of GHD.

Automated perimetry in the management of glaucoma.

As optometry's role and responsibilities increase, so does our need to understand and utilize new technological advances to aid in our understanding and management of ocular conditions. Automated perimetry represents one such technological improvement that enhances our ability to detect and analyze the visual field changes associated with glaucoma. An understanding of the automated perimeter's abilities and limitations is needed to effectively incorporate it into the management of glaucoma.

Trauma-induced altitudinal hemianopsia.

A 55-year-old Caucasian female presented with bilateral inferior altitudinal visual field defects which resulted from trauma suffered in an automobile accident. In addition, there was a bilateral reduction in visual acuities and bilateral optic disc pallor. Diagnostic and historical data suggested that the primary site of damage was at the occipital cortex. A subsequent bilateral anterior ischemic optic neuropathy process was also thought to have occurred.

Electrophysiological assessment of visual deficit in glaucoma.

Steady-state visual evoked potentials (VEP(S)) in response to contrast reversed vertical grating patterns and uniformly flickering fields were recorded in patients with glaucoma and in controls. In steady-state VEP(S), responses to temporal and spatial aspects of visual stimuli are combined, which makes the assessment of visual function dependent on their interaction. Fourier analysis of pattern reversal VEP waveforms showed marked deficits in temporal processing of spatial contrast for glaucoma patients. The degree of glaucomatous damage, as manifested by greater optic nerve atrophy and visual field loss, was correlated with progressive disruption of the VEP waveform and progressive failure in temporal processing of spatial contrast patterns. The VEP(S) in response to uniform full-field flicker showed no deficit.

Interexaminer reliability of the optic cup to disc ratio assessment.

Previous controlled reliability studies of cup to disc (C/D) ratio estimations may have been biased by lack of criteria for cup determination, small sample size; and/or large interval grouping of collected data. In our study four examiners independently estimated the C/D ratios of 40 patients by direct ophthalmoscopy using a contour criterion for cup determination. Results indicated that 75% of the estimate pairs differed by 0.10 or less. Fewer than 14% of the estimate pairs differed by 0.2 or greater. The results of the study suggest that when examiners use a specified criterion of contour cupping, interexaminer assessment of the C/D ratio estimation is clinically and statistically reliable.

Transient vision loss associated with Barlow's syndrome.

Barlow's syndrome, also known as mitral valve prolapse, is a common and generally benign cardiological condition. Various reports have implicated this syndrome in the precipitation of embolic oculo-ischemic events. A 33-year-old male presented with complaints of unilateral transient vision loss over a six-month period. Auscultation revealed a mid-systolic click and late systolic murmur, classic of Barlow's syndrome. Referral and subsequent echocardiography confirmed the diagnosis. Mitral valve prolapse should be considered in the differential diagnosis of transient vision loss in a young patient.

Contemporary viewpoints on pigmentary glaucoma.

The pigment dispersion syndrome occasionally results in a specific form of open angle glaucoma (pigmentary glaucoma). Recent evidence suggests a mechanical etiology of pigment liberation. Consideration of these etiological factors influences the optometric management of patients with pigment dispersion syndrome and pigmentary glaucoma. A review of anatomical and histological factors as well as a representative case report are presented.