Disease relevance of Sclera

• Latrotoxin receptor (CL1AA) and optimedin were shown to be expressed in the iris and ciliary body, as well as in the ganglion and inner nuclear cell layers of the retina, whereas the rat orthologue of the human HNOEL-iso gene was expressed in the iris and sclera and less actively in the trabecular meshwork, retina, and optic nerve [1].
• RESULTS: Sixteen (80%) of 20 cases developed severe scleral necrosis that required tectonic surgery after bare sclera pterygium excision with mitomycin C or beta-irradiation [2].
• The significance of hypertelorism, obliquity of eyes, long palpebral fissures, blue scleras, depressed bridge of nose, and prominent upper vermilion border is discussed [3].
• Peripapillary atrophy was divided into (1) a central zone (zone Beta) with visible, large choroidal vessels and sclera, and (2) a peripheral zone (zone Alpha) with irregular hyper- and hypopigmentation [4].
• Synthesis of nitric oxide (NO) was blocked by L-NMMA (200 mg kg-1 b.w., i.v.). PGF2 alpha-IE induced marked hyperemia of the surface structures of the eye (conjunctiva, eye lids, nictitating membrane, anterior sclera), as well as increased blood flow of the anterior uvea [5].

High impact information on Sclera

• ELISA studies and crossed immunoelectrophoresis demonstrated that purified dermatan sulphate proteoglycans isolated from bovine sclera did not react with these antibodies but that the antibody to cartilage proteoglycan reacted with other molecules extracted from sclera [6].
• Surprisingly, the TIGR message, which is abundantly transcribed in the trabecular meshwork and also in the ciliary body and the sclera, is not expressed in the optic nerve whose degeneration is, however, the primary lesion of POAG [7].
• IGF-II mRNA was expressed by the loose mesenchymal orbital tissue as it differentiated to form the sclera, but not in the compact mature sclera or cornea, or in the ectodermally derived retina or skin [8].
• These data represent the first demonstration of TGF-beta3 expression in the sclera and implicate all three TGF-beta isoforms in the control of scleral remodeling during myopia development [9].
• Reduced collagen fibril diameter is also observed in the sclera of eyes with high myopia [10].

Chemical compound and disease context of Sclera

• PURPOSE: To evaluate the safety and efficacy of intraoperative daunorubicin during a bare sclera procedure in primary pterygium surgery and to compare with conjunctival autograft [11].
• METHODS: Fresh sclera was inoculated with Staphylococcus aureus, Streptococcus pneumoniae, or Pseudomonas aeruginosa and transferred to preservative vials containing glycerin, 95% ethanol, or trypticase soy broth (control) and stored at room temperature [12].
• Various ocular structures (iris, ciliary body, choroid, retina, sclera, optic nerve) were enucleated from human eyes suffering endophthalmitis, perforative wounds of cornea and/or sclera, or uncontrolled glaucoma, and were tested for their histamine content [13].
• We previously reported that expression of retinoic acid receptor beta increases in the sclera of the 2-week-old chick with form deprivation myopia (FDM) and that all-trans-retinoic acid (t-RA) influences proliferation and differentiation of scleral cells [14].

Biological context of Sclera

• The sclera of embryonic (days 10 and 14) and young adult (2-week posthatching chicks) contains distinct binding sites for insulin and for insulin-like growth factor-1 (IGF-1) [15].
• The insulin binding site in the sclera is specific for insulin since it has a high affinity for insulin and a lower affinity for IGF-1 (IC50 for unlabeled insulin = 0.4 nM; unlabeled IGF-1 = 5.0 nM) [15].
• At intraocular pressures higher than the systolic arterial blood pressure there was still some accumulation of 2-DG in the intraocular tissues, but no blood flow, which indicates that glucose could diffuse into the eye through the sclera [16].
• We wanted to determine changes in gene expression in the operated and companion eye following lensectomy, especially for extracellular matrix in the sclera [17].
• RESULTS: Latanoprost or PhXA34 had no or only a slight effect on the regional blood flow when measured 1, 2 1/2, 3, 4 1/2, and 6 hours after dose administration, with the exception of the anterior sclera, in which a moderate increase in blood flow was detected [18].

Anatomical context of Sclera

• CRAD mRNA expression was widespread (relative abundance): kidney (100) > liver (92) > small intestine (9) = heart (9) > retinal pigment epithelium and sclera (4.5) > brain (2) > retina and vitreous (1.6) > spleen (0.7) > testis (0.6) > lung (0.4) [19].
• The dermatan sulfate proteoglycans of bovine sclera and their relationship to those of articular cartilage. An immunological and biochemical study [20].
• Keratocan is abundant in cornea and sclera and detected in much lesser amounts in skin, ligament, cartilage, artery, and striated muscles [21].
• The mean values for the diffusion coefficients of krypton obtained in this study were 1.6 X 10(-5), 0.76 X 10(-5), 0.80 X 10(-5), and 1.2 X 10(-5) cm.2 per second for the sclera, choroid, retina, and vitreous, respectively [22].
• When the apparatus was placed over the bulbar conjunctiva, a sufficient amount of 5-FU to inhibit fibroblast proliferation was introduced into the conjunctiva and sclera with a current of 0.5 mA passed for 30 seconds [23].

Associations of Sclera with chemical compounds

• These studies demonstrate that the larger dermatan sulfate proteoglycans of sclera and cartilage are chemically unrelated to each other and to the smaller dermatan sulfate proteoglycans isolated from these tissues [20].
• The distribution of proteoglycans and their association with collagen fibrils were studied in human and rabbit sclera following fixation of tissue in glutaraldehyde containing Cuprolinic Blue, a specific stain for proteoglycans when used in the presence of critical concentrations of electrolytes [24].
• Chicks were monocularly occluded for 10 days and the DNA, hydroxyproline, and glycosaminoglycan contents of the sclera were compared between the normal and the myopic eyes [25].
• PURPOSE: The present study was undertaken to determine whether exposure of the sclera to prostaglandin (PG)F(2alpha) or to the PGF(2alpha) analogue latanoprost acid alters mRNA for matrix metalloproteinases [26].
• Normal pigmented and albino rabbits showed similar levels of gentamicin in the cornea, aqueous, and vitreous; however, the drug was barely detectable in iris, choroid-retina, and sclera of pigmented animals, presumably on account of an interaction with melanin-containing tissues [27].

Gene context of Sclera

• RESULTS: Normal human uvea, retina, sclera, and conjunctiva constitutively expressed TLR4, MD-2, and CD14 mRNA [28].
• However, collagen I immunoreactivity in sclera and associated structures was greater in Col1a1(r/r) mice than in Col1a1(+/+) mice [29].
• Among the eye tissues analyzed, Myoc/Tigr mRNA was detected in the combined tissues of the eye angle, sclera, cornea, retina, and optic nerve head [30].
• Low levels of Eya2 expression was detected in retina, sclera, and cornea [31].
• MMP-2 was found in sclera, cornea, choroid, vitreous, RPE and retina but was absent from lens [32].

Analytical, diagnostic and therapeutic context of Sclera

• All the large proteoglycans, i.e. from tendon, sclera, cartilage and aorta, appear to contain the structure typical for the hyaluronic acid-binding region, both shown by enzyme-linked immunosorbent assay and by content of peptides unique for this region [33].
• RT-PCR analysis of total RNA isolated from human sclera and HSFs confirmed the presence of EP(1), EP(2), and FP receptor subtypes [34].
• In contrast, other cell types of the normal human cornea, conjunctiva, retina, and sclera did not express TLR4/MD-2 protein in vivo as detectable by immunohistochemistry [28].
• After 6 to 8 weeks, the rats were anesthetized with a subcutaneous injection of urethane, and the sclera was exposed [35].
• Additionally, we used radial immunodiffusion to measure levels of Factor B, IgG, IgA and albumin in the anterior and posterior sclera [36].

References