Faculty Bibliography

Purpose of Review: In this review, we summarize both contrast fractional flow reserve (cFFR) and computed tomography fractional flow reserve (CT-FFR) as novel modalities to evaluate the hemodynamic significance of coronary artery stenoses and to guide percutaneous coronary intervention (PCI). Recent Findings: Implementation of cFFR can reduce the time, cost, effort, and patient discomfort associated with traditional adenosine FFR. Clinical outcomes following cFFR-guided revascularization are currently under investigation. Emerging data on the use of CT-FFR in patients with acute coronary syndromes may increase the use of this technology in acute settings, while virtual stenting applications to model the hemodynamic results of stent placement may help optimize PCI planning.
Summary: Using contrast media already available for traditional angiography, cFFR yields results that are highly reproducible and correlate more closely with traditional adenosine FFR than the distal/aortic pressure ratio (Pd/Pa) or the instantaneous wave-free ratio (iFR). Based upon computational fluid dynamics, CT-FFR provides a non-invasive estimate of the traditional adenosine FFR and predicts ischemia more accurately than nuclear imaging. Therefore, CT-FFR has begun to take on a gatekeeper role to minimize unnecessary invasive angiography.
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BACKGROUND AND PURPOSE/OBJECTIVE:RTT, caused by mutations in the methyl CPG binding protein 2 (MeCP2) gene, is a disorder of neuronal maturation and connections. Our aim was to prospectively examine FA by DTI and correlate this with certain clinical features in patients with RTT. MATERIALS AND METHODS/METHODS:Thirty-two patients with RTT underwent neurologic assessments and DTI. Thirty-seven age-matched healthy female control subjects were studied for comparison. With use of a 1.5T MR imaging unit, DTI data were acquired, and FA was evaluated to investigate multiple regional tract-specific abnormalities in patients with RTT. RESULTS:In RTT, significant reductions in FA were noted in the genu and splenium of the corpus callosum and external capsule, with regions of significant reductions in the cingulate, internal capsule, posterior thalamic radiation, and frontal white matter. In contrast, FA of visual pathways was similar to control subjects. FA in the superior longitudinal fasciculus, which is associated with speech, was equal to control subjects in patients with preserved speech (phrases and sentences) (P = .542), whereas FA was reduced in those patients who were nonverbal or speaking only single words (P < .001). No correlations between FA values for tracts and clinical features such as seizures, gross or fine motor skills, and head circumference were identified. CONCLUSIONS:DTI, a noninvasive technique to assess white matter tract pathologic features, may add specificity to the assessment of RTT clinical severity that is presently based on the classification of MeCP2 gene mutation and X-inactivation.

PURPOSE: Despite the established efficacy of mitomycin C (MMC) in preventing recurrence after pterygium surgery, there is no consensus on the optimal operative technique or dose of MMC. METHODS: The authors retrospectively evaluated 90 single-headed pterygium resections performed with excision of the entire pterygium to the plica and removal of all Tenon's membrane from the scleral bed and rectus muscle. Bare sclera was exposed to 0.4 mg/mL MMC for 5 minutes for primary pterygia and 6 minutes for recurrent pterygia. These procedures were compared to a previous series of 58 procedures using bare sclera technique with MMC, but without extensive Tenon's membrane removal. RESULTS: Extensive Tenon's membrane removal was associated with significantly fewer recurrences (6.7% vs. 21%; P< or =0.025) and significantly less pyogenic granuloma formation (24.4% vs. 40%; P< or =0.05). In addition, there were no vision-threatening complications, such as scleral melting or persistent corneal epithelial defects, in any of the patients. CONCLUSIONS: These findings suggest that complete removal of all Tenon's membrane in the affected quadrant combined with topical MMC in the aforementioned dose is a safe method of pterygium excision with a low rate of recurrence and pyogenic granuloma formation

OBJECTIVE:To utilize neuroimaging procedures to assess the extent of cerebral involvement in female subjects heterozygous for X-linked adrenoleukodystrophy (X-ALD). METHODS:Brain MRI studies were performed in 76 female subjects heterozygous for X-ALD (mean age 43 years, range 8 to 75 years). Sixty-five had clinical evidence of spinal cord involvement resembling that in males with adrenomyeloneuropathy (AMN), two had clinical evidence of cerebral involvement, and nine showed no neurologic abnormality. Readers blinded to clinical findings further analyzed abnormal MRI studies. In eight women whose MRI results were normal, four-slice long echo time MRS imaging (MRSI) studies were performed and compared to those of eight age-matched controls. RESULTS:MRI results were normal in 65 subjects and abnormal in 11. In eight of the latter group, the MRI changes were judged to be due to causes other than X-ALD. Lesions were attributed to X-ALD in the remaining three. Two of these patients had lesions that resembled those in male patients with cerebral X-ALD. In one patient with a mild AMN-like syndrome, brain MRI abnormalities were confined to the corticospinal tract. When compared to those of controls, MRSI studies in eight female patients with normal results on brain MRI showed a significant reduction of N-acetylaspartate/creatine and N-acetylaspartate/choline ratios in the internal capsule and corticospinal projection fibers. The N-acetylaspartate/choline ratio was significantly reduced in the parieto-occipital white matter and the choline/creatine ratio was significantly increased in the frontal white matter. CONCLUSION/CONCLUSIONS:Brain involvement demonstrable by MRI is rare in female subjects heterozygous for X-ALD, including those who have clinical evidence of spinal cord involvement. Nevertheless, N-acetylaspartate levels are reduced in the corticospinal projection fibers in female subjects with normal results on MRI, suggesting axonal dysfunction.

PURPOSE: A body of clinical and laboratory evidence suggests that tinted spectacle lenses may have an effect on visual performance. The aim of this study was to quantify the effects of spectacle lens tint on the visual performance of 25 subjects with cataracts. METHODS: Cataracts were scored based on best-corrected acuity and by comparison with the Lens Opacity Classification System (LOCS III) plates. Visual performance was assessed by measuring contrast sensitivity with and without glare (Morphonome software version 4.0). The effect of gray, brown, yellow, green and purple tinting was evaluated. RESULTS: All subjects demonstrated an increase in contrast thresholds under glare conditions regardless of lens tint. However, brown and yellow lens tints resulted in the least amount of contrast threshold increase. Gray lens tint resulted in the largest contrast threshold increase. CONCLUSIONS: Individuals with lenticular changes may benefit from brown or yellow spectacle lenses under glare conditions

PURPOSE: To determine the correlation between the aesthetics of lens tints preferred for cosmesis and lens tints preferred for viewing. METHODS: Thirty-five subjects (mean age: 25; 49% male, 51% female) with no significant ocular pathology participated in the study. Median visual acuity was 20/20. Color vision testing was performed on each subject using Ishihara plates, and those with abnormal scores were excluded from the study. Subjects were shown nine pre-selected tinted lenses (50% transmittance) of variable wavelengths. These lenses were mounted on two separate color backgrounds, one white and the other approximating their skin tone. Subjects were asked to choose from each background which tinted lens they would most prefer to wear and which lens they would least prefer to wear. The subjects were then shown a series of eight pictures (four nature photographs and four paintings) with different dominant wavelengths. Subjects were asked to grade the aesthetic effect of a clear lens and each of the nine tinted lenses on the appearance of the pictures. Chromaticity coordinates were calculated for each lens and picture. RESULTS: The blue lens was the most frequently chosen preferred lens to wear, followed by green, purple, and gray. The least preferred lenses were yellow, brown, and pink. For viewing the nature photographs, the clear lens was preferred over any of the tinted lenses. For viewing the paintings, the purple lens was most preferred. The yellow lens was least preferred for both photographs and paintings. CONCLUSIONS: Younger individuals with no significant ocular pathology preferred viewing both nature photographs and paintings through tinted lenses that did not, or only slightly, altered the chromaticity of the image. Whereas a clear lens was favored over the tinted lenses for viewing the photographs, some tinted lenses (purple and pink) were preferred for viewing paintings. There was no correlation between the most favored lens tint chosen based purely on cosmesis and the most favored lens tint based on viewing preference. However, the least preferred lens tint for cosmesis and viewing was yellow