View revision history Report problem with Article. Citation, DOI and article data. Rezaee, A. Tenon capsule. Reference article, Radiopaedia. Tenon fascia fascia bulbi bulbar sheath Tenon's capsule. URL of Article. Tenon capsule is composed of anterior and posterior parts: the anterior, or muscular, part is a thick fibrous tissue containing collagen, elastin and smooth muscles the posterior part is merely condensed collagen fibers History and etymology It is named after the French surgeon and pathologist JR Tenon , who described it in Related pathology subconjunctival fat prolapse.
Observations of the episclera and Tenon's capsule posterior to the equator have so far been limited mostly to surgical situations e.
Histologic studies have rarely been focused on the posterior episclera or Tenon's capsule. The clinical introduction of optical coherence tomography OCT has made it possible to visualize the posterior ocular segment including the sclera. Imamura et al. Using swept-source OCT as a further refinement of the OCT technology, we observed the full posterior sclera in a previous study of eyes with high myopia. Thus, the purpose of the present swept-source OCT study was to perform a further analysis of collected images, with a focus on the features of the episclera and Tenon's capsule in the posterior segment of eyes with high myopia.
The Ethics Committee of the Tokyo Medical and Dental University approved the investigation and confirmed that the methods used in our study conformed to the tenets of the Declaration of Helsinki. The ethics committee waived informed consent, since this study involved a reevaluation of images collected in our previously approved study, and since the previously collected data were deidentified. Exclusion criteria were a lack of clear OCT images, and a history of previous vitreoretinal surgery, since it could have affected the scleral curvature.
All patients underwent a comprehensive ophthalmologic examination including refraction, ocular biometry for measurement of axial length IOLMaster; Carl Zeiss Meditec Co. The optical coherence tomography examination was carried out using a prototype of a swept-source OCT device Topcon Corp.
This device had an A-scan repetition rate of , Hz. The light source used was a wavelength-sweeping laser centered at nm with a bandwidth of approximately nm. The effective bandwidth was roughly 60 nm due to water absorption. The imaging depth in the tissue was 2. Our scanning protocol included a pattern of mm long radial scans along 12 meridians centered on the fovea. A single image was made up of A-line scans acquired in 10 ms. Each scan consisted of 32 B-scan images which were recorded and averaged by postprocessing to yield a despeckled, high-quality B-scan image.
Since the scleral shape was bent, the scleral thickness was measured along an axis orientated perpendicularly to the eye surface Fig. Figure 1. View Original Download Slide. Methods used to measure the thickness of the sclera, episclera, and Tenon's capsule. The thickness was measured along the perpendicular axis to the curvature of the retinal pigment epithelium. Double-headed red arrow : sclera. Blue bar : episclera. Yellow bar : Tenon's capsule. Note: Cross-section of an intrascleral blood vessel surrounded by loose tissue.
The sclera appears thickened in that region. The choroid is barely detectable except for a few large vessels. Figure 1 Methods used to measure the thickness of the sclera, episclera, and Tenon's capsule. The statistical analysis was carried out using a commercially available statistical software program SPSS version Since the parameters were not normally distributed, as shown by the Kolmogorov-Smirnov test, the statistical significance of the differences between the two groups of eyes was assessed by the Mann-Whitney U test for unpaired samples.
The differences in measurements between two locations within the same eye were examined by the Wilcoxon-test for paired samples. Additionally, we carried out a 1-way ANOVA to compare the measurements obtained at different locations in the same eye.
All P -values were two-sided and considered to be statistically significant if their value was lower than 0. Out of highly myopic eyes, which had undergone swept-source OCT examination in the study period, the entire sclera was visualized in all 12 radial foveal scans in eyes The episclera appeared as a relatively uniform structure with a reflectivity that was slightly lower than the scleral reflectivity Fig.
The episclera was closely attached to the outer surface of the sclera in most areas; although in some regions, especially in the macular area, the episclera was clearly separated from the outer surface of the sclera Figs. The latter finding suggested that the episclera represented a different tissue, distinct from the sclera proper. The border between the sclera and episclera was relatively clear in most eyes due to differences in reflectivity between these tissues.
Because the subfoveal choroid was too thin to be measured in most eyes included in our study, choroidal thickness was not included in the list of outcome parameters. Background: The microscopic and macroscopic anatomy of the anterior and posterior Tenons capsule is described.
Methods: An observational anatomic study of twelve orbits of 6 cadavers mean age After orbital exenteration, an X-shaped incision was made in the specimens to include the posterior part of the globe.
It is slung like a hammock below the eyeball, being expanded in the center, and narrow at its extremities which are attached to the zygomatic and lacrimal bones respectively. Relations to extraocular muscles It is perforated by the tendons of the ocular muscles, and is reflected backward on each as a tubular sheath.
Category : Anatomy. Cookies help us deliver our services.
0コメント