AIMTo determine the effect of pH, osmolality, and buffering system on the oxygen permeability (Dk) of soft contact lenses.METHODSTwo hydrogel lenses (nelfilcon A and etafilcon A) and 2 silicone hydrogel lenses (lotraf...AIMTo determine the effect of pH, osmolality, and buffering system on the oxygen permeability (Dk) of soft contact lenses.METHODSTwo hydrogel lenses (nelfilcon A and etafilcon A) and 2 silicone hydrogel lenses (lotrafilcon A and balafilcon A) were used in the study. These lenses were incubated in phosphate-buffered saline (PBS) and borate-buffered saline (BBS) solutions adjusted by 0.8 pH increments to a pH in the range of 5.8-9.0 or in hypotonic (280 mOsmol/kg), isotonic (310 mOsmol/kg) and hypertonic (380 mOsmol/kg) PBS solutions. Polarographic method was used for measuring the Dk and lenses were stacked as 4 layers to correct the boundary effect.RESULTSDk values of all contact lenses measured in BBS solutions were more stable than those in PBS solutions. Especially the etafilcon A lens showed a relative big change compared with other types of contact lenses at the same conditions. When the osmolality of PBS solution increased from hypotonic to hypertonic, Dk of all contact lenses decreased. Variations in Dk existed depending on lens materials, etafilcon A lens was the most affected and nelfilcon A was the least affected by osmolality.CONCLUSIONFrom the result obtained, it is revealed that Dk of contact lenses is changed by the pH, osmolality, and buffering condition of tear. Thus, Dk of contact lens can be varied by the lens wearers' physiological and/or pathological conditions.展开更多
Purpose: Reasons for the lack of success for contact lens patients range from poor fit, to discomfort or to a less than optimum wearing schedule. This project was a preliminary investigation of customized soft toric c...Purpose: Reasons for the lack of success for contact lens patients range from poor fit, to discomfort or to a less than optimum wearing schedule. This project was a preliminary investigation of customized soft toric contact lenses as an alternative for unsuccessful contact lens patients or potential drop-outs. Methods: Fifteen healthy non-compromised, previously unsuccessful contact lens wearing patients (13 women, 2 men) with ages from 21 to 33 years (25.1 ± 2.7 years) were the subjects for this study. They were empirically fitted with 15 astigmatic and 5 spherical customized SpecialEyes soft contact lenses. Visual acuities, comfort, lens movement, and rotation were evaluated. Results: Patients fitted with customized SpecialEyes soft contact lenses had statistically significant better visual acuities than with Phoropter Manifest Refraction. The lenses used in this study centered well and moved no more than 1 mm upon each blink. Lens rotation was less than 10 degrees for all toric lenses. Patients gave very positive vision and comfort ratings. Conclusion: This preliminary study supports the application of a software program to empirically design and manufacture Special Eyes custom soft lenses based upon corneal topographical parameters and subjective manifest refraction for those patients who either have challenging corneal parameters, high sphero-cylindrical prescriptions, or are currently dissatisfied with their contact lenses and are potential drop-outs.展开更多
Purpose: To investigate the efficacy and complications of continuous wear of etafilcon A for therapeutic use. Materials and Methods: The subjects were 228 eyes of 219 outpatients prescribed contact lens (CL) for one w...Purpose: To investigate the efficacy and complications of continuous wear of etafilcon A for therapeutic use. Materials and Methods: The subjects were 228 eyes of 219 outpatients prescribed contact lens (CL) for one week of continuous therapeutic wear during 10 years. The reason for prescription of CLs, the primary disease, the duration of CL wear and the complications were assessed retrospectively. Results: The predominant reason for prescription of CLs was relief of pain or a foreign-body sensation (62.3%) and protection of the corneal epithelium (20.6%). The primary disease was post-penetrating keratoplasty (36.8%), followed by corneal epithelial erosion (14.5%), post-lamellar keratoplasty (14.0%) and bullous keratopathy (12.2%). The average duration of wearing single lens was 6.5 ± 3.2 days. The average duration of wearing CLs in total was 9.2 ± 10.7 months. The most frequent problem associated with continuous wear of CLs was their dropping out of CLs (12.3%). The complications associated with CLs included conjunctivitis with papillary hyperplasia, corneal erosion and superficial punctate keratitis, but corneal ulcer and corneal infiltrates were not found. Conclusion: Serious complications were not shown changing the lenses every week to keep to the prescribed time limit for continuous therapeutic wear, even if corneal epithelial barrier function is impaired.展开更多
目的:研究儿童配戴RGP镜片后角膜敏感性的变化。方法:采用问卷的形式收集基本信息,应用Cochet and Bonnet aesthesiometer测量67例134眼角膜敏感性,按照不同分组进行比较分析。结果:儿童戴镜1～12mo组,戴镜1～5a组中央部和下方角膜敏感...目的:研究儿童配戴RGP镜片后角膜敏感性的变化。方法:采用问卷的形式收集基本信息,应用Cochet and Bonnet aesthesiometer测量67例134眼角膜敏感性,按照不同分组进行比较分析。结果:儿童戴镜1～12mo组,戴镜1～5a组中央部和下方角膜敏感性明显下降(中央P=0.000,下方P=0.002),而2组之间的差异无显著意义(中央P=0.997,下方P=0.056)。儿童戴镜1～5a组颞侧,鼻侧,上方角膜敏感性明显下降(颞侧P=0.000,鼻侧P=0.000,上方P=0.001),戴镜1～5a组与戴镜1～12mo组(颞侧P=0.133,鼻侧P=0.125,上方P=0.205),未戴镜组与戴镜1～12mo组(颞侧P=0.06,鼻侧P=0.200,上方P=0.207),差异均无显著意义。儿童与成年人分别配戴RGP镜片1～12mo和1～5a,中央角膜敏感性无显著差异(1～12moP=0.343,1～5aP=0.105)。结论:RGP镜片对于儿童和成人的中央角膜敏感性的影响是相似的。但由于儿童自身的特点,为儿童验配RGP仍应慎重。展开更多
文摘AIMTo determine the effect of pH, osmolality, and buffering system on the oxygen permeability (Dk) of soft contact lenses.METHODSTwo hydrogel lenses (nelfilcon A and etafilcon A) and 2 silicone hydrogel lenses (lotrafilcon A and balafilcon A) were used in the study. These lenses were incubated in phosphate-buffered saline (PBS) and borate-buffered saline (BBS) solutions adjusted by 0.8 pH increments to a pH in the range of 5.8-9.0 or in hypotonic (280 mOsmol/kg), isotonic (310 mOsmol/kg) and hypertonic (380 mOsmol/kg) PBS solutions. Polarographic method was used for measuring the Dk and lenses were stacked as 4 layers to correct the boundary effect.RESULTSDk values of all contact lenses measured in BBS solutions were more stable than those in PBS solutions. Especially the etafilcon A lens showed a relative big change compared with other types of contact lenses at the same conditions. When the osmolality of PBS solution increased from hypotonic to hypertonic, Dk of all contact lenses decreased. Variations in Dk existed depending on lens materials, etafilcon A lens was the most affected and nelfilcon A was the least affected by osmolality.CONCLUSIONFrom the result obtained, it is revealed that Dk of contact lenses is changed by the pH, osmolality, and buffering condition of tear. Thus, Dk of contact lens can be varied by the lens wearers' physiological and/or pathological conditions.
文摘Purpose: Reasons for the lack of success for contact lens patients range from poor fit, to discomfort or to a less than optimum wearing schedule. This project was a preliminary investigation of customized soft toric contact lenses as an alternative for unsuccessful contact lens patients or potential drop-outs. Methods: Fifteen healthy non-compromised, previously unsuccessful contact lens wearing patients (13 women, 2 men) with ages from 21 to 33 years (25.1 ± 2.7 years) were the subjects for this study. They were empirically fitted with 15 astigmatic and 5 spherical customized SpecialEyes soft contact lenses. Visual acuities, comfort, lens movement, and rotation were evaluated. Results: Patients fitted with customized SpecialEyes soft contact lenses had statistically significant better visual acuities than with Phoropter Manifest Refraction. The lenses used in this study centered well and moved no more than 1 mm upon each blink. Lens rotation was less than 10 degrees for all toric lenses. Patients gave very positive vision and comfort ratings. Conclusion: This preliminary study supports the application of a software program to empirically design and manufacture Special Eyes custom soft lenses based upon corneal topographical parameters and subjective manifest refraction for those patients who either have challenging corneal parameters, high sphero-cylindrical prescriptions, or are currently dissatisfied with their contact lenses and are potential drop-outs.
文摘Purpose: To investigate the efficacy and complications of continuous wear of etafilcon A for therapeutic use. Materials and Methods: The subjects were 228 eyes of 219 outpatients prescribed contact lens (CL) for one week of continuous therapeutic wear during 10 years. The reason for prescription of CLs, the primary disease, the duration of CL wear and the complications were assessed retrospectively. Results: The predominant reason for prescription of CLs was relief of pain or a foreign-body sensation (62.3%) and protection of the corneal epithelium (20.6%). The primary disease was post-penetrating keratoplasty (36.8%), followed by corneal epithelial erosion (14.5%), post-lamellar keratoplasty (14.0%) and bullous keratopathy (12.2%). The average duration of wearing single lens was 6.5 ± 3.2 days. The average duration of wearing CLs in total was 9.2 ± 10.7 months. The most frequent problem associated with continuous wear of CLs was their dropping out of CLs (12.3%). The complications associated with CLs included conjunctivitis with papillary hyperplasia, corneal erosion and superficial punctate keratitis, but corneal ulcer and corneal infiltrates were not found. Conclusion: Serious complications were not shown changing the lenses every week to keep to the prescribed time limit for continuous therapeutic wear, even if corneal epithelial barrier function is impaired.
文摘目的:研究儿童配戴RGP镜片后角膜敏感性的变化。方法:采用问卷的形式收集基本信息,应用Cochet and Bonnet aesthesiometer测量67例134眼角膜敏感性,按照不同分组进行比较分析。结果:儿童戴镜1～12mo组,戴镜1～5a组中央部和下方角膜敏感性明显下降(中央P=0.000,下方P=0.002),而2组之间的差异无显著意义(中央P=0.997,下方P=0.056)。儿童戴镜1～5a组颞侧,鼻侧,上方角膜敏感性明显下降(颞侧P=0.000,鼻侧P=0.000,上方P=0.001),戴镜1～5a组与戴镜1～12mo组(颞侧P=0.133,鼻侧P=0.125,上方P=0.205),未戴镜组与戴镜1～12mo组(颞侧P=0.06,鼻侧P=0.200,上方P=0.207),差异均无显著意义。儿童与成年人分别配戴RGP镜片1～12mo和1～5a,中央角膜敏感性无显著差异(1～12moP=0.343,1～5aP=0.105)。结论:RGP镜片对于儿童和成人的中央角膜敏感性的影响是相似的。但由于儿童自身的特点,为儿童验配RGP仍应慎重。
