scholarly journals Evaluation of the impact of tear layer thickness in scleral lenses on the optical quality of the eye by means of Optical Quality Analysis System (OQAS)

2018 ◽  
Vol 96 (S261) ◽  
pp. 127-128
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhonghao Ren ◽  
Liyan Xu ◽  
Qi Fan ◽  
Kaili Yang ◽  
Shengwei Ren ◽  
...  

Purpose. The study aimed to evaluate the visual quality of forme fruste keratoconus (FFK) and mild and moderate keratoconus by using an optical quality analysis system II (OQAS-II) and to explore the correlation between optical quality parameters and the disease progression. Methods. Twenty-one normal eyes, twenty-one FFK eyes, twenty-one mild keratoconus eyes, and twenty-one moderate keratoconus eyes were included in this prospective study. The optical quality parameters, such as object scatter index (OSI), modulation transfer function cutoff (MTF cutoff), strehl ratio (SR), and OQAS-II values at contrasts of 100% (OV-100), 20% (OV-20), and 9% (OV-9), were measured by OQAS-II. The repeatability of these parameters was analyzed by intraclass correlation coefficient (ICC), repeatability coefficient (RC), and coefficient of variation (CVw). Correlations between optical quality parameters and mean central keratometry readings (Kmean) were evaluated. The sensitivity and specificity of the parameters were analyzed using the receiver operating characteristic (ROC). Results. All the optical quality parameters among four groups showed good repeatability (all ICC≥0.75). The MTF cutoff, SR, OV-100, OV-20, OV-9 in FFK, mild and moderate keratoconus eyes were significantly lower than those in the normal group (all P<0.05). The ROC analyses of the MTF cutoff, SR, OV-100, OV-20, and OV-9 showed significant area under the curve (AUC) in discriminating FFK form normal, mild keratoconus from FFK, and moderate keratoconus from mild keratoconus (all P<0.05). The OSI in mild and moderate keratoconus eyes were significantly higher than that in FFK and normal group (all P<0.05), while the OSI showed no significant difference between the FFK group and normal group (P>0.05). The ROC analyses of the OSI showed significant AUC in discriminating mild keratoconus from FFK and moderate keratoconus from mild keratoconus (all P<0.05). In addition, the MTF cutoff was closely correlated to Kmean in keratoconus eyes (r = −0.710, P<0.001). Conclusion. The repeatability of OQAS-II is good in measuring visual quality of normal as well as FFK, mild, and moderate keratoconus. The visual quality of the FFK, mild, and moderate keratoconus is worse than that in normal eyes. The OQAS-II has the potential value in screening FFK from normal eyes and might be a useful tool for evaluating the progression of keratoconus.


2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Yu-jing Wang ◽  
Yan-ning Yang ◽  
Lin-ying Huang ◽  
Bo Wang ◽  
Yu-can Han ◽  
...  

Background.To evaluate the optical quality and related factors in patients with ocular hypertension (OHT).Methods.This was a prospective case-control study. A total of 12 eyes with OHT and 20 control eyes underwent testing with Optical Quality Analysis System II (OQAS II) to evaluate the modulation transfer function cut off frequency (MTF cutoff), the Strehl 2D ratio (SR), objective scatter index (OSI), tear-film mean OSI (TFOSI), and the OQAS values (OV100%,OV20%, and OV9%).Results.The optical quality of patients with OHT declined, with lower MTF cutoff (OHT 36.86 ± 7.11 cpd , controls 48.50 ± 4.04 cpd,t=-4.60,P<0.05), lower SR (OHT 0.22 ± 0.04, controls 0.27 ± 0.05,t=-2.72,P<0.05), lower OV100% (OHT 1.26 ± 0.25, controls 1.61 ± 0.14,t=-4.03,P<0.05), lower OV20% (OHT 1.27 ± 0.27, controls 1.72 ± 0.20,t=-4.00,P<0.05), and lower OV9% (OHT 1.30 ± 0.25, controls 1.69 ± 0.32,t=-2.28,P<0.05). There were not any statistically significant differences in OSI and TFOSI. The MTF cutoff in patients with OHT was correlated significantly with age (r=-0.59,P<0.05).Conclusions.Optical quality of patients with OHT is reduced, with lower MTF cutoff, SR, OV100%, OV20%, and OV9%. MTF cutoff is negatively related to age.


2019 ◽  
Author(s):  
Yang Zhang ◽  
Ailing Bian ◽  
Qijun Hang ◽  
Qi Zhou

Abstract Purpose To investigate if optical quality assessed by Optical Quality Analysis System(OQAS)is a new factor for psychological disturbance and vision related quality of life(QoL) in Chinese patients with primary open angle glaucoma (POAG).Methods Cross-sectional study. OQAS, automated static perimetry, the Hospital Anxiety and Depression Scale (HADS) Questionnaire and the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) were used to assess optical quality, vision field, psychological health and QoL in 64 POAG patients. Correlation between the OQAS parameters and QoL or psychological health was analyzed by linear regression model.Results OQAS parameters, the modulation transfer function cut off frequency (MTF cutoff) and the mean OQAS values (mean OV), were significantly related to mean deviation (MD). Statistically significant correlation was also found between MTF cutoff, the mean OV and QoL in more than half of the NEI VFQ-25 subscale scores and the composite. The correlation coefficients between OQAS parameters and QoL were similar to those between MD and QoL in most of the subscale scores. HADS-Depression and HADS-Anxiety scores significantly correlated with MD in the worse eye, the composite and 3subscales of NEI VFQ-25, general health, social function and mental health, but uncorrelated with optical quality parameters measured by OQAS.Conclusions OQAS assessed optic quality is negatively related to MD and is a valid indicator for vision related QoL, but not for psychological health in our study group. OQAS might be an alternative or supplement to perimeter in POAG patients.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bo Lu ◽  
Weijie Zhu ◽  
Yu Fan ◽  
Dong Shi ◽  
Liwei Ma

Abstract Background A prospective cohort study was performed to evaluate whether the Optical Quality Analysis System (OQAS) can serve as a valuable additional indicator for appropriate posterior capsulotomy referral. Methods One hundred and five eyes from 96 patients undergoing capsulotomy were divided into precapsulotomy logMAR CDVA ≤0.1 group and logMAR CDVA > 0.1 group. CDVA, and the Visual Function 14 index (VF-14) score were estimated before and 1 month after capsulotomy. The objective scattering index (OSI) value was measured by using the OQAS. Posterior capsule opacification (PCO) severity was assessed with Evaluation of PCO 2000 (EPCO 2000) software. Results In logMAR CDVA > 0.1 group, the correlations of OSI, logMAR CDVA, EPCO score and VF-14 score were very strong preoperatively. In logMAR CDVA ≤0.1 group, preoperatively, OSI was correlated with logMAR CDVA (r = 0.451), EPCO score (r = 0.789), and VF-14 score (r = 0.852). LogMAR CDVA has weak correlation with VF-14 score (r = − 0.384) and EPCO score (r = 0.566). VF-14 score was correlated with EPCO score (r = − 0.669). In the logMAR CDVA ≤0.1 group, there was no significant difference in logMAR CDVA between precapsulotomy and postcapsulotomy (P > 0.05). In the two groups, all the other optical quality parameters were significantly improved after capsulotomy (P < 0.05). In logMAR CDVA > 0.1 group, the area under the curve of the ROC of the OSI was 0.996 (P = 0.000). In logMAR CDVA ≤0.1 group, the area under the curve of the ROC of the OSI was 0.943 (P = 0.000). Conclusions The OSI was useful for evaluating of PCO and prediction of beneficial capsulotomy. Especially for patients with slight PCO and better visual acuity, OSI is more valuable than CDVA and completely objective examination. Trial registration The study protocol was registered at the Chinese Clinical Trial Registry. Register: ChiCTR1800018842 (Registered Date: October 13th, 2018).


2012 ◽  
Vol 236-237 ◽  
pp. 839-843
Author(s):  
Xiao Meng Cui ◽  
Guang Xue Chen ◽  
Huan Mei Wang ◽  
Lin Lin Chen

In this study we present a new framework to assess line micro quality of multicolor prints adapted to a low-cost image quality analysis system based on common flatbed scanner. The contribution elements including quality metrics, measurement principle, applying methods and detection instrument, which were complemented and sorted in terms of ISO 13660 standard, were described and a case experiment was conducted to survey the output performance of both inkjet printer and xerographic printer, two most popular digital printing technologies. Their qualities were compared in details rendering angle such as width and straightness of line, raggedness and blurriness in line edges, as well as darkness and contrast in color. The results verify the efficiency and shortcomings of the framework. Meanwhile, the metric values let us take an investigation in the character of each digital printing technology in micron size.


2017 ◽  
Vol 14 (3) ◽  
pp. 251
Author(s):  
Rita Yulianti ◽  
Emi Sukiyah ◽  
Nana Sulaksana

Daerah penelitian terletak di desa Muaro Limun, Kecamatan Limun Kabupaten Sarolangun Provinsi Jambi. Sungai limun, salah satu sungai besar di daerah kabupaten sarolangun yang dimanfaatkan oleh mayarakat sekitarnya sebagai sumber penghidupan. Penelitian bertujuan untuk mengetahui pengaruh kegiatan penambangan terhadap kualitas air sungai Batang Limun, dan perubahan sifat fisik dan  kimia yang diakibatkan   kegiatan penambangan.Metode yang digunakan adalah  metode grab sampel, serta stream sedimen untuk dianalis di laboratorium. Sejumlah sampel diambil di beberapa lokasi Penambangan Emas berdasarkan Aliran Sub-DAS dan dibandingkan dengan beberapa sampel lain yang diambil pada lokasi yang belum terkontaminasi oleh kegiatan penambangan. Analisis kualitas air mengacu pada  SMEWWke 22 tahun 2012 dan standar baku mutu air kelas II dalam PP No 82 yang dikeluarkan oleh Menteri Kesehatan No. 492/Menkes/Per/IV/2010. Diketahui sungai Batang Limun telah mengalami perubahan karakteristik fisika dan kimia. Dari grafik  kosentrasi kekeruhan, pH, TSS, TDS  Cu, Pb, Zn, Mn, Hg terlihat bahwa penambang emas tanpa izin (PETI) dengan cara amalgamasi yang menyebabkan terjadinya penurunan kualitas air sungai. Sejak tahun 2009 sampai tahun 2015  sungai Limun dan sekitarnya terus mengalami penurunan kualitas air. Penurunan kualitas yang cukup tinggi terjadi  yaitu peningkatan nilai Rata-rata konsentrasi merkuri pada sungai Batang Limun dari 0,18ppb (0,00018 mg/l)  menjadi 0,3ppb (0,0003 mg/l), peningkatan tersebut dipengaruhi oleh proses kegiatan penambangan dan nilai tersebut masih dibawah standar baku mutu air kelas II  pp nomor 82 tahun 2010.Kata kunci :   Kualitas Air, Sungai Limun,TSS, Merkuri, PETI Limun river is one of the major rivers in the area of Sarolangun, which utilized by the society as a source of livelihood. The aim of study  to analyze the effect of mining activities on  the water quality of Batang Limun River, and the changes of physical and chemical properties of water. The method used are grab  and stream samples to  sediment analyzed in the laboratory. A number of samples were taken at several locations based Flow Gold Mining Sub-watershed and compared to some other samples taken at the location that has not been contaminated by mining activities. Water quality analysis referring to SMEWW, 22nd edition 2012 and refers to Regulation No 82 that issued by Minister of Health No. 492 / Menkes / Per / IV / 2010.The results showed that the Limun river has undergone chemical changes in physical characteristics. These symptoms can be seen from the discoloration of clear water in the river before the mine becomes brownish after mining, based on graphic of muddiness concentration: pH, TSS, TDS Cu, Pb, Zn, Mn, Hg have seen that  the illegal miner which used amalgamation caused deterioration in water quality, data from 2009 to 2015 Limun river and surrounding areas continue to experience a decrease in water quality. The decreasing of water quality showed in the TSS parameter which found in the area is to high based on  the standard of water quality class II pp number 82 of 2010. An increase in the value of average concentrations of mercury in the Batang Limun river before mine 0,18ppb (0.00018 mg / l) into 0,3ppb (0.0003 mg / l) on the river after the mine. The increase was affected by the mining activities and the value is still below the air quality standard Grade II pp numbers 82 years 2010, although the value is still below with the standards quality standard, the mercury levels in water should still be a major concern because if it accumulates continuously in the water levels will increase and will be bad for health. In contrast to the concentration of mercury in sediments that have a higher value is 153 ppb (0,513ppm ) .Key Words :   Water Quality, Limun River, Mercury, Illegal gold mining


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