Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 6839928

Cataract, pattern stimulation and visually evoked potentials.

G H van Lith·W Hekkert-Wiebenga
View original source ↗Export metadata ↓

Abstract

Visually evoked potentials on pattern stimulation are lowered by cataracts via scatter, absorption and defocusing. These effects have to be known before pattern stimulation can be fruitfully applied in patients when a lowered vision cannot or can hardly be explained by the cataract. It was remarkable that pattern responses were relatively good as compared to visual acuity. With a pattern of 80' check size and 80% contrast all patients with a visual acuity of more than 0.1 had recognizable responses; this holds also true with 40' check size and 40% contrast in all patients with a visual acuity of more than 0.3. Reversely, with 10' check size and 10% contrast only half of the normal subjects had detectable responses.

Explore related subjects

CataractEvoked Potentials, VisualHumansVision TestsVisual AcuityJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

G H van Lith, W Hekkert-Wiebenga. 1983-02-28. Cataract, pattern stimulation and visually evoked potentials.. https://doi.org/10.1007/bf00140467

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

KLF5 promotes proliferation, migration, and autophagy-/EMT‑associated molecular changes in lens epithelial cells via transcriptional activation of THBS1 in traumatic cataract.

PURPOSE: Traumatic cataract is a common blinding eye disease after ocular trauma, and its pathogenesis is closely related to lens epithelial cell dysfunction, while the definite molecular regulatory mechanism between upstream transcription factor and downstream target gene remains poorly clarified. This study aimed to clarify the role and molecular mechanism of the krüppel-like factor 5 (KLF5)/ thrombosponin 1 (THBS1) axis in regulating proliferation, migration, epithelial-mesenchymal transition and autophagy of lens epithelial cells in traumatic cataract, and to explore its potential clinical therapeutic value. METHODS: The GSE295383 dataset in the gene expression omnibus (GEO) database was downloaded, and the differentially expressed genes (DEGs) were screened by linear models for microarray data (limma) package of R language. Combined with Weighted gene co-expression network analysis (WGCNA), the gene co-expression network was constructed and the key modules were screened. Gene ontology (GO), kyoto encyclopedia of genes and genomes (KEGG) and gene set enrichment analysis (GSEA) combined with human transcription factor target (hTFtarget) and JASPAR databases were used to predict the upstream transcription factors of THBS1. Subsequently, SRA01/04 cells were induced with transforming growth factor-beta 2 (TGF-β2) to construct a cataract cell model. RESULTS: THBS1 and KLF5 were highly expressed in LECs exposed to TGF-β2. KLF5 could activate THBS1 transcription by binding to THBS1 promoter - 174 to -165 sites. Knockdown of THBS1 inhibited TGF-β2-induced viability, proliferation, migration, and altered the expression of epithelial-mesenchymal transition (EMT)- and autophagy-related markers in LECs. Knockdown of KLF5 downregulated THBS1 expression and produced a similar inhibitory effect, while overexpression of THBS1 reversed the effect of KLF5 knockdown. CONCLUSIONS: This study demonstrated that KLF5 promoted the proliferation, migration, and EMT‑associated molecular changes of LECs in traumatic cataract through transcriptional activation of THBS1, and regulated the expression of autophagy‑related markers in LECs, suggesting that KLF5/THBS1 axis might be a potential target for the treatment of traumatic cataract.

Cataract↗
PubMed2007

Solubility, uptake and biocompatibility of lutein and zeaxanthin delivered to cultured human retinal pigment epithelial cells in tween40 micelles.

Carotenoids lutein and zeaxanthin are proposed to protect ocular tissues from free-radical damage that can cause cataract and age-related macular degeneration (AMD). They accumulate selectively in the lens and macular region of the retina. Changes in the retinal pigment epithelium are characteristic in AMD. Efficient uptake is essential to study the intracellular effects of carotenoids in cell cultures. For in vitro experiments carotenoids are often dissolved in organic solvents like tetrahydrofuran (THF), dimethylsulfoxide (DMSO) and n-hexane, but difficulties have been associated with these application methods. Recently, O'Sullivan et al. (SM O'Sullivan et al., Br J Nutr 91 (2004) 757) developed a method whereby carotenoids could be delivered to cultured cells without the cytotoxic side effects often observed when organic solvents are used. We modified this method and investigated the effects of different carotenoid-formulations (ethanol/Tween40, methanol/tween40 and acetone/Tween40) on the uptake of lutein and zeaxanthin by differentiated ARPE-19 cells, cell viability and the expression of the "stress" gene HO-1, which is easily induced by a range of stimuli including chemical and physical agents. Micelle formulations prepared with ethanol/Tween40 resulted in the lowest LDH release, the highest carotenoid uptake and the lowest stress response (changes in HO-1 mRNA expression).

Cataract↗
PubMed2007

Determining corneal power using Orbscan II videokeratography for intraocular lens calculation after excimer laser surgery for myopia.

PURPOSE: To assess the accuracy of Orbscan II slit-scanning videokeratography for intraocular lens (IOL) calculation in eyes with previous photorefractive surgery for myopia. SETTING: Private practice, St. Louis, Missouri, USA. METHODS: Corneal power (K) was measured by manual keratometry, Placido-based videokeratography (Atlas), slit-scanning videokeratography (Orbscan II), and contact lens overrefraction in 21 post-photoablation eyes having cataract surgery. Postoperative data collected after phacoemulsification were used to back-calculate corneal power (BCK). The BCK values were statistically compared at 3.0 to 6.0 mm central Orbscan II curvature and power measurements, including total axial power, total tangential power, total mean power, and total optical power. Similar comparisons were made to Atlas curvature at the 0.0 to 10.0 mm zones. RESULTS: The mean corneal power after refractive surgery based on BCK values using the Holladay 2 formula (BCK H2) was 39.35 diopters (D) +/- 2.58 (SD). The mean manual value (40.52 +/- 1.95 D) and Atlas-based values were statistically higher than BCK H2 values (P<.001). The mean corneal power calculated from historical data was 39.33 +/- 2.70 D (P = .83 to BCK H2; n = 19) and from contact lens overrefraction, 41.38 +/- 3.11 D (P = .19; n = 5). Orbscan II parameters (n = 21) of the total mean power (3.0 mm, 39.10 +/- 2.63 D), total tangential power (3.0 mm, 39.11 +/- 2.60), total axial power (5.0 mm, 39.19 +/- 2.55 D), and total optical power (3.0 mm, 39.08 +/- 2.78 D; 4.0 mm, 39.39 +/- 2.76 D) were statistically similar to both the historical and BCK H2 values (P>.11). If used prospectively, 80.9% of eyes would have been within +/-0.50 D of the targeted refraction using a 4.0 mm total optical power, 76.2% using a 5.0 mm total axial power, and 42.1% using the historical method. CONCLUSION: The Orbscan II 5.0 mm total axial power and 4.0 mm total optical power can be used to more accurately predict true corneal power than the history-based method and may be particularly useful when pre-LASIK data are unavailable.

Cataract↗