SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Scleral lens

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: To assess the relationship between the thinnest corneal location and the steepest and maximum elevation corneal locations in subjects with keratoconus and the effect of gas permeable contact lens wear on the location of these points.

Concepts: Cornea, Lens, Orthokeratology, Contact lens, Contact lenses, Keratitis, Keratoconus, Scleral lens

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Scleral contact lenses (ScCL) have gained renewed interest during the last decade. Originally, they were primarily used for severely compromised eyes. Corneal ectasia and exposure conditions were the primary indications. However, the indication range of ScCL in contact lens practices seems to be expanding, and it now increasingly includes less severe and even non-compromised eyes, too. All lenses that partly or entirely rest on the sclera are included under the name ScCL in this paper; although the Scleral Lens Education Society recommends further classification. When a lens partly rests on the cornea (centrally or peripherally) and partly on the sclera, it is called a corneo-scleral lens. A lens that rests entirely on the sclera is classified as a scleral lens (up to 25mm in diameter maximum). When there is full bearing on the sclera, further distinctions of the scleral lens group include mini-scleral and large-scleral lenses. This manuscript presents a review of the current applications of different ScCL (all types), their fitting methods, and their clinical outcomes including potential adverse events. Adverse events with these lenses are rare, but the clinician needs to be aware of them to avoid further damage in eyes that often are already compromised. The use of scleral lenses for non-pathological eyes is discussed in this paper.

Concepts: Eye, Cornea, Lens, Orthokeratology, Contact lens, Contact lenses, Keratoconus, Scleral lens

1

Keratoconus (KC) is a progressive corneal ectasia linked to thinning of the central cornea. Hard contact lenses, rigid gas permeable lenses, and scleral lenses are the primary treatment modalities for early to mid- stages of KC to correct refractive error and astigmatism that develops as a result of an irregular corneal structure. These treatments are associated with significant drawbacks, including reduced availability of the tear film and oxygen to the corneal epithelium and stroma. However, it remains unknown whether hypoxia affects corneal integrity in the KC pathobiology. A number of studies have associated elevated oxidative stress with KC both in vitro and ex vivo. We hypothesized that KC-derived corneal fibroblasts are more susceptible to hypoxia-induced oxidative stress compared to healthy controls leading to exacerbation of corneal thinning in KC. This study investigated the effects of hypoxia on ECM secretion, assembly, and matrix metalloproteinase (MMP) expression in human corneal fibroblasts from healthy controls (HCFs) and KC patients (HKCs) in vitro. HCFs and HKCs were cultured in 3D constructs for 3 weeks and maintained or transferred to normoxic (21% O2) or hypoxic (2% O2) conditions, respectively, for 1 additional week. At the 4 week time-point, constructs were isolated and probed for Collagen I, III, and V, keratocan and MMP-1, -2, -3, -9, and -13, as well as hypoxia markers, hypoxia inducible factor-1α and lactoferrin. Conditioned media was also collected and probed for Collagen I, III, and V by Western blot. Thickness of the ECM assembled by HCFs and HKCs was measured using immunofluorescence microscopy. Results showed that hypoxia significantly reduced Collagen I secretion in HKCs, as well as upregulated the expression of MMP-1 and -2 with no significant effects on MMP-3, -9, or -13. ECM thickness was reduced in both cell types following 1 week in a low oxygen environment. Our study shows that hypoxia influences collagen and MMP expression by HKCs, which may have consequential effects on ECM structure in the context of KC.

Concepts: Cornea, Corneal transplantation, Astigmatism, Contact lens, Contact lenses, Tears, Keratoconus, Scleral lens

0

To develop a methodology to reliably determine the thickness profile of scleral contact lenses and examine the relationship between the centre and average lens thickness for a range of lens designs and back vertex powers.

Concepts: Cornea, Myopia, Lens, Contact lens, Corrective lens, Intraocular lens, Corrective lenses, Scleral lens

0

Debris accumulation in the postlens fluid reservoir during scleral lens wear is clinically observed. We evaluated a method to quantify increases in turbidity of the postlens fluid reservoir by assessing changes in optical density of the fluid over time and compared these changes during 2 hr of scleral lens wear using three different lens designs.

Concepts: Scientific method, Light, Liquid, Scleral lens

0

This study showed an improvement in three-dimensional depth perception of subjects with bilateral and unilateral keratoconus with rigid gas-permeable (RGP) contact lens wear, relative to spectacles. This novel information will aid clinicians to consider RGP contact lenses as a management modality in keratoconic patients complaining of depth-related difficulties with their spectacles.

Concepts: Cornea, Depth perception, Myopia, Contact lens, Contact lenses, Corrective lens, Keratoconus, Scleral lens

0

To summarize the research findings on the ocular surface profile, to provide a definition and a classification of the corneoscleral shape, and to offer guidelines in selecting scleral lens design.

Concepts: Lens, Scleral lens

0

To assess the visual quality achieved by fitting corneo-scleral contact lenses (CScL) for keratoconus management.

Concepts: Evaluation, Contact lens, Keratoconus, Scleral lens

0

To describe indications and outcomes of patients fitted with the EyePrintPRO therapeutic scleral lens.

Concepts: Cornea, Myopia, Lens, Contact lens, Contact lenses, Corrective lens, Keratoconus, Scleral lens

0

To analyze the state of scientific publications in the field of scleral lenses applying a bibliometric study.

Concepts: Scientific method, Mathematics, Academic publishing, Science, Research, State, Scleral lens