The Normative Retinal and Choroidal Thicknesses of the Rabbit as Revealed by Spectral Domain Optical Coherence Tomography

Purpose@#We used spectral domain optical coherence tomography (SD-OCT) to assess the retinal and choroidal thicknesses of the rabbit, a commonly used animal model of ophthalmic disease. We report normative datasets. @*Methods@#Semi-automated measurements were made on 15 normal right eyes of New Zealand white rabbits. Total retinal, inner retinal layer, outer retinal layer, choroidal, ganglion cell layer, ganglion cell complex, inner nuclear layer, and outer nuclear layer thicknesses were measured at fixed distances (0, 1, 2, 3, 4, and 5 mm) below the optic nerve head. @*Results@#Total retinal layer (Pearson’s correlation coefficient [CC] = -0.778, p < 0.05), inner retinal layer (CC = -0.710, p < 0.05), outer retinal layer (CC = -0.495, p < 0.05), ganglion cell complex (CC = -0.292, p < 0.05), ganglion cell layer (CC = -0.284, p < 0.05), and outer nuclear layer thicknesses (CC = -0.760, p < 0.05) decreased with the distance from the optic nerve head. Inner nuclear layer thickness correlated negatively with the distance from the optic nerve head, but the correlation coefficient was low (CC = -0.263, p < 0.05). Choroidal thickness increased with the distance from the optic nerve head (CC = 0.511, p < 0.05). @*Conclusions@#Rabbit retinal thicknesses were measured and analyzed by the distance from the optic nerve head. The datasets will serve as standards when using rabbits.

The Normative Retinal and Choroidal Thicknesses of the Rabbit as Revealed by Spectral Domain Optical Coherence Tomography

Purpose@#We used spectral domain optical coherence tomography (SD-OCT) to assess the retinal and choroidal thicknesses of the rabbit, a commonly used animal model of ophthalmic disease. We report normative datasets. @*Methods@#Semi-automated measurements were made on 15 normal right eyes of New Zealand white rabbits. Total retinal, inner retinal layer, outer retinal layer, choroidal, ganglion cell layer, ganglion cell complex, inner nuclear layer, and outer nuclear layer thicknesses were measured at fixed distances (0, 1, 2, 3, 4, and 5 mm) below the optic nerve head. @*Results@#Total retinal layer (Pearson’s correlation coefficient [CC] = -0.778, p < 0.05), inner retinal layer (CC = -0.710, p < 0.05), outer retinal layer (CC = -0.495, p < 0.05), ganglion cell complex (CC = -0.292, p < 0.05), ganglion cell layer (CC = -0.284, p < 0.05), and outer nuclear layer thicknesses (CC = -0.760, p < 0.05) decreased with the distance from the optic nerve head. Inner nuclear layer thickness correlated negatively with the distance from the optic nerve head, but the correlation coefficient was low (CC = -0.263, p < 0.05). Choroidal thickness increased with the distance from the optic nerve head (CC = 0.511, p < 0.05). @*Conclusions@#Rabbit retinal thicknesses were measured and analyzed by the distance from the optic nerve head. The datasets will serve as standards when using rabbits.

Semi-quantitative strain elastography may facilitate pre-surgical prediction of mandibular lymph nodes malignancy in dogs

Evaluation of mandibular lymph nodes in a patient with head and neck cancer is important for stage determination and prognosis development, and, in human medicine, the use of sonoelastography for differentiating between non-metastatic and metastatic lymph nodes has been reported. Our prospective, cross-sectional study aimed to evaluate the diagnostic performance of strain elastography and to determine elastographic cut-off values for predicting malignancy. Sixty-six mandibular lymph nodes were included (clinical healthy, n = 45; non-metastatic, n = 8; and metastatic, n = 13). Elastographic images were evaluated qualitatively (elastographic pattern) and semi-quantitatively (mean hue histogram and stiffness area ratios). Elastographic patterns were classified as grades 1 to 4, according to the percentage of high elasticity determined by visualization. The mean hue histogram was defined based on as the mean pixel color values within the lymph node. Stiffness area ratios were determined by computer program analysis of the stiff area. Among the criteria, receiver operating characteristic curve analyses revealed cut-off values for the prediction of malignancy of 92.26 for mean hue histogram (sensitivity: 100%, specificity: 92%), and 0.17 for stiffness area ratios (sensitivity: 86%, specificity of 100%). Reproducibility and repeatability were excellent. In conclusion, semi-quantitative evaluation via strain elastography holds potential for predicting lymph node malignancy.

Comparison of Nd:YAG Capsulotomy Rates between Hydrophobic and Hydrophilic Intraocular Lenses

PURPOSE: To compare neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy rates between hydrophobic and hydrophilic intraocular lenses. METHODS: The present retrospective study enrolled patients who received cataract surgery from a single surgeon between July 2006 to December 2009. Patients included in the study were implanted with SA60AT hydrophobic spherical intraocular lenses (Alcon, Fort Worth, TX, USA, 268 eyes) or I-FLEX hydrophilic spheric intraocular lenses (i-Medical®, Ophthalmic International Heidelberg GmbH, Mannheim, Germany, 331 eyes). The Nd:YAG capsulotomy rates and best-corrected visual acuity (BCVA) were compared between the two groups for 2 years after the operation. RESULTS: The mean follow-up period was 23.5 months and 22.6 months and the mean age was 68.6 years and 70.3 years in the SA60AT and I-FLEX groups, respectively. Follow-up periods were longer in the SA60AT group (p = 0.035), but ages were not significantly different between the two groups (p = 0.367). Nd:YAG laser capsulotomy rates were 6.3% in the SA60AT group and 11.2% in the I-FLEX group. Nd:YAG laser capsulotomy rates were significantly higher in the I-FLEX group (p = 0.020). BCVA before and after the Nd:YAG laser capsulotomy was not significantly different. CONCLUSIONS: Nd:YAG laser capsulotomy rates were higher in the I-FLEX hydrophilic spheric intraocular lens group than in the SA60AT hydrophilic spheric intraocular lens group. Adhesion between capsular bag and intraocular lens by bioadhesive character of hydrophobic acryl intraocular lens may contribute to the prevention of lens epithelial migration and posterior capsule opacification.

Comparison of Nd:YAG Capsulotomy Rates between Hydrophobic and Hydrophilic Intraocular Lenses

PURPOSE: To compare neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy rates between hydrophobic and hydrophilic intraocular lenses. METHODS: The present retrospective study enrolled patients who received cataract surgery from a single surgeon between July 2006 to December 2009. Patients included in the study were implanted with SA60AT hydrophobic spherical intraocular lenses (Alcon, Fort Worth, TX, USA, 268 eyes) or I-FLEX hydrophilic spheric intraocular lenses (i-Medical®, Ophthalmic International Heidelberg GmbH, Mannheim, Germany, 331 eyes). The Nd:YAG capsulotomy rates and best-corrected visual acuity (BCVA) were compared between the two groups for 2 years after the operation. RESULTS: The mean follow-up period was 23.5 months and 22.6 months and the mean age was 68.6 years and 70.3 years in the SA60AT and I-FLEX groups, respectively. Follow-up periods were longer in the SA60AT group (p = 0.035), but ages were not significantly different between the two groups (p = 0.367). Nd:YAG laser capsulotomy rates were 6.3% in the SA60AT group and 11.2% in the I-FLEX group. Nd:YAG laser capsulotomy rates were significantly higher in the I-FLEX group (p = 0.020). BCVA before and after the Nd:YAG laser capsulotomy was not significantly different. CONCLUSIONS: Nd:YAG laser capsulotomy rates were higher in the I-FLEX hydrophilic spheric intraocular lens group than in the SA60AT hydrophilic spheric intraocular lens group. Adhesion between capsular bag and intraocular lens by bioadhesive character of hydrophobic acryl intraocular lens may contribute to the prevention of lens epithelial migration and posterior capsule opacification.

Cerebellar maturation ratio of forebrain and brainstem at magnetic resonance imaging in the micropig / 대한수의학회지

The study of pigs as a human disease model has been conducted in neuroscience. But the morphological development of pig brain by using MRI is rare. The purpose of this study is to determine whether cerebellum maintains consistent proportion to other brain regions in aging. Clinically healthy sixteen micropigs, 1, 2, 4, and 8 months were studied. The micropigs were anesthetized with isoflorane. MRI was acquired using a 0.3T system. To figure out development of ratio that allowed identification of normal cerebellum size, we measured the area of the cerebellum, brainstem, and forebrain from the mid-sagittal brain images on T1W. Mid-sagittal cross-sectional area (CSA) of total brain, forebrain, brainstem, and cerebellum were expressed as absolute values and also as percentages which were compared between the four age groups of micropigs for the purpose to define the effect of age on brain morphometry. It was found that there was not a significant difference in the percentage of the brain occupied by an individual region between groups although the absolute CSA differed significantly among age groups. There was no effect of age on the ratio between the cerebellum and total brain in 4 age groups. The normal size of cerebellum changes during brain development maintained a consistent ratio to other brain regions in normal micropigs. The ratio of CSA quantified on the mid-sagittal MR images offers a suitable method to detect presence of cerebellar anomalies in micropigs.

Evaluation of the lateral ventricle using MRI in normal micropigs / 대한수의학회지

This study was undertaken to assess the lateral ventricle, which was some portion of brain and related to congenital anomalies, from 1, 2, 4, and 8 months of age in healthy micropigs. They were induced general anesthesia and performed magnetic resonance imaging (MRI) with a 0.3 Tesla magnet. Each age group was evaluated by three subjects such as lateral ventricular volume, ventricular volume ratio and asymmetry. T1 weighted transverse images were acquired for calculation of lateral ventricular and corresponding brain parenchyma areas. The ratio of bilateral ventricle areas used to analyze the asymmetry. The mean ventricular volumes of each month were 676.74 +/- 25.58 mm3 (1 month-old), 630.64 +/- 143.84 mm3 (2 month-old), 992.12 +/- 106.03 mm3 (4 month-old) and 1172.62 +/- 237.57 mm3 (8 month-old), respectively. The ventricular volume ratio was the smallest at 2 month-old and re-increased from that age. The ratio was significantly different between 2 month-old and other age groups (p < 0.05). The value of bilateral area ratio showed within 1.5 in all experimental animals. Consequently the lateral ventricle showed a positive correlation with aging and symmetric shapes in both sides. The developmental pattern of the lateral ventricle provides basic data in micropigs as an experimental animal model for physiological and neurosurgical approach.