10 research outputs found
Comment on amniotic membrane covering promotes healing of cornea epithelium and improves visual acuity after debridement for fungal keratitis
Comment & Respons
Construction of a patterned hydrogelfibrous mat bilayer structure to mimic choroid and Bruch's membrane layers of retina
Deterioration of retina and death of the retinal cells due to age, diabetes, or occlusion can cause retinal degeneration which leads to loss of vision. In this study, it is aimed to design a bilayered matrix to mimic the choroid and the Bruch's membrane of the retinal tissue. As choroid, a microchanneled network resembling a fractal tree design was fabricated by photolithography over photo-cross-linkable methacrylated hyaluronic acid hydrogel. Gelatin or collagen was immobilized into the microchannels to enhance adherence of Human Umbilical Vein Endothelial Cells (HUVEC). At late culture periods (2 weeks), formation of tubular structures due to proliferation of the attached cells was observed. As Bruch's membrane, an electrospun fibroin nanofiber mat was produced to grow retinal pigment epithelium (RPE) cells on. Cellular interactions between RPE and HUVEC in the microchannels were investigated in a coculture model in a noncontact mode. It was deduced that by combining the RPE layer on the highly permeable Bruch's membrane with the choroid layer populated by HUVECs, a retinal substitute which might have a potential for use in the treatment of retinal diseases is possible. (c) 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2166-2177, 2016
Color vision versus pattern visual evoked potentials in the assessment of subclinical optic pathway involvement in multiple sclerosis
Background: Optic pathway involvement in multiple sclerosis is frequently the initial sign in the disease process. In most clinical applications, pattern visual evoked potential (PVEP) is used in the assessment of optic pathway involvement. Objective: To question the value of PVEP against color vision assessment in the diagnosis of subclinical optic pathway involvement. Materials and Methods: This prospective, cross-sectional study included 20 multiple sclerosis patients without a history of optic neuritis, and 20 healthy control subjects. Farnsworth-Munsell (FM) 100-Hue testing and PVEPs to 60-min arc and 15-min arc checks by using Roland-Consult RetiScan® system were performed. P 100 amplitude, P 100 latency in PVEP and total error scores (TES) in FM 100-Hue test were assessed. Results: Expanded Disability Status Scale score and the time from diagnosis were 2.21 ± 2.53 (ranging from 0 to 7) and 4.1 ± 4.4 years. MS group showed significantly delayed P 100 latency for both checks (P 0.05 for all). 14 MS patients (70%) had an increased TESs in FM-100 Hue, 11 (55%) MS patients had delayed P 100 latency and 9 (45%) had reduced P 100 amplitude. The areas under the ROC curves were 0.944 for FM-100 Hue test, 0.753 for P 100 latency, and 0.173 for P 100 amplitude. Conclusions: Color vision testing seems to be more sensitive than PVEP in detecting subclinical visual pathway involvement in MS
Acute Effect of Cigarette Smoking on Pupil Size and Ocular Aberrations: A Pre- and Postsmoking Study
Aim. To evaluate the acute effects of cigarette smoking on photopic and mesopic pupil sizes and wavefront aberrations. Methods. Cigarette smoker volunteers were recruited in the study. Photopic and mesopic pupil sizes and total ocular aberrations were measured before smoking and immediately after smoking. All volunteers were asked to smoke a single cigarette containing 1.0 mg nicotine. Pupil sizes and total ocular aberrations were assessed by optical path difference scanning system (OPD-Scan II ARK-10000, NIDEK). Only the right eyes were considered for statistical analysis. The changes of pupil size and total ocular aberrations after smoking were tested for significance by Wilcoxon signed ranks test. Results. Mean photopic pupil size decreased from 3.52 ± 0.73 mm to 3.29 ± 0.58 mm (P=0.001) after smoking. Mean mesopic pupil size was also decreased from 6.42 ± 0.75 mm to 6.14 ± 0.75 mm after smoking (P=0.001). There was a decrease in all the measured components of aberrations (total wavefront aberration, higher-order aberration, total coma, total trefoil, total tetrafoil, total spherical aberration and total higher-order aberration) after smoking; however the differences were insignificant for all (P>0.05). Conclusion. Our results indicate that pupil constricts after smoking. On the other hand, smoking does not alter ocular aberrations
Acute Effect of Cigarette Smoking on Pupil Size and Ocular Aberrations: A Pre-and Postsmoking Study
Aim. To evaluate the acute effects of cigarette smoking on photopic and mesopic pupil sizes and wavefront aberrations. Methods. Cigarette smoker volunteers were recruited in the study. Photopic and mesopic pupil sizes and total ocular aberrations were measured before smoking and immediately after smoking. All volunteers were asked to smoke a single cigarette containing 1.0 mg nicotine. Pupil sizes and total ocular aberrations were assessed by optical path difference scanning system (OPD-Scan II ARK-10000, NIDEK). Only the right eyes were considered for statistical analysis. The changes of pupil size and total ocular aberrations after smoking were tested for significance by Wilcoxon signed ranks test. Results. Mean photopic pupil size decreased from 3.52 ± 0.73 mm to 3.29 ± 0.58 mm ( = 0.001) after smoking. Mean mesopic pupil size was also decreased from 6.42 ± 0.75 mm to 6.14 ± 0.75 mm after smoking ( = 0.001). There was a decrease in all the measured components of aberrations (total wavefront aberration, higher-order aberration, total coma, total trefoil, total tetrafoil, total spherical aberration and total higher-order aberration) after smoking; however the differences were insignificant for all ( > 0.05). Conclusion. Our results indicate that pupil constricts after smoking. On the other hand, smoking does not alter ocular aberrations