配戴离焦RGPCL对高度近视儿童角膜屈光力及散光量的影响

目的：对比观察高度近视儿童配戴离焦硬性透气性角膜接触镜(RGPCL)前后角膜屈光力改变,并分析配戴后镜片对角膜屈光力及散光量的影响。

方法：自身前后对照研究。收集2019-06/2020-06在西安市第一医院眼视光中心就诊并验配离焦RGPCL的8～12岁高度近视儿童30例60眼。使用TMS-4N角膜地形图仪测量基线及戴镜0.5、1a时戴镜状态下角膜切向屈光力,分析角膜鼻侧(N)、颞侧(T)、上方(S)和下方(I)角膜最大屈光力值及中央顶点处角膜屈光力改变情况,同时以1mm为间隔采集前述4个方位角膜屈光力以及角膜顶点处屈光力,采集范围为1～4mm,分析戴镜前后各点位屈光力变化情况。戴镜0.5,1a时后要求停戴1wk后复测眼轴、屈光度和角膜地形图,分析戴镜后较基线时眼轴、等效球镜度、散光和角膜屈光力等改变情况。

结果：配戴离焦RGPCL时鼻侧(N)、颞侧(T)、上方(S)和下方(I)的角膜最大屈光力在0.5、1a时较戴镜前均显著增加,与角膜顶点处屈光力相比均表现为正相对屈光力,与戴镜前的负相对屈光力相比具有显著差异。在戴镜0.5、1a时复诊时戴镜状态下角膜相对周边屈光力朝正屈光力方向改变,除T1点位周边负屈光力增加外,其余各轴向各点位周边屈光力均显著增加。配戴0.5a后角膜陡K值变平0.11±0.10D,simK值减少0.20±0.18D,1a后角膜陡K值变平0.10±0.12D,平均K值变平0.02±0.05D,simK值减少0.16±0.13D。戴镜0.5、1a时后角膜平K较基线变化无差异。

结论：配戴离焦RGPCL状态下角膜最大屈光力较角膜顶点处均表现为正相对屈光力,且4条轴向上各点位角膜相对周边负屈光力均由负值转变为正值。戴镜1a内眼轴和等效球镜度均较基线时增加,而散光量减少,角膜屈光力呈陡K变平趋势。     

软性与透气性硬性角膜接触镜配戴者角膜地形图及前房深度对比分析

目的　比较配戴软性及硬性角膜接触镜对角膜形态及前房深度的影响。方法　选取屈光不正患者６０例（１２０眼）,分别予以配戴软性角膜接触镜（ｓｏｆｔｃｏｎｔａｃｔｌｅｎｓ,ＳＣＬ）及透气性硬性角膜接触镜（ｒｉｇｉｄｇａｓｐｅｒｍｅａｂｌｅｃｏｎｔａｃｔｌｅｎｓ,ＲＧＰＣＬ）,其中ＳＣＬ组３０例（６０眼）,ＲＧＰＣＬ组３０例（６０眼）,ＯｂｓｃａｎⅡ角膜地形图观察戴镜前及戴镜后１ａ、２ａ角膜屈光力、角膜前后表面Ｄｉｆｆ值、中央角膜厚度、前房深度的变化。结果　戴镜前ＲＧＰＣＬ组角膜上下表面屈光力差值为（０．９８±０．４９）Ｄ,戴镜后１ａ为（０．６６±０．４３）Ｄ,戴镜后２ａ为（０．５９±０．３７）Ｄ,均较戴镜前减小（Ｐ＜０．０５）;戴镜后１ａ、２ａ角膜前表面屈光力均较戴镜前降低,差异均有统计学意义（均为Ｐ＜０．０５）。ＳＣＬ组戴镜后１ａ、２ａ角膜前后表面屈光力、Ｉ－Ｓ值、前后表面Ｄｉｆｆ值、前房深度与戴镜前比较,差异均无统计学意义（均为Ｐ＞０．０５）;戴镜前中央角膜厚度为（５４９±２６）μｍ,戴镜后１ａ为（５２７±２９）μｍ,与戴镜前比较差异无统计学意义（Ｐ＞０．０５）,戴镜后２ａ为（５０９±３１）μｍ,与戴镜前比较差异有统计学意义（Ｐ＜０．０５）。结论　长期配戴ＲＧＰＣＬ对角膜代谢和功能影响不明显,且能够提供更好的光学矫正效果。     

多焦软性角膜接触镜对周边屈光度及周边角膜屈光力的影响

目的：:观察配戴多焦软性角膜接触镜引起的周边屈光度及周边角膜屈光力的变化,研究二者之间的关系。方法：:自身对照研究。于2020年10月1─15日在温州医科大学收集成年近视受检者18例,在配戴单焦软性角膜接触镜（简称单焦软镜）和多焦软性角膜接触镜（简称多焦软镜）状态下分别采用红外自动验光仪和角膜地形图测量周边屈光度及周边...     

硬性透气性角膜接触镜与软性角膜接触镜对中低度近视患者角膜形态的影响

目的　探讨屈光不正患者长期配戴软性角膜接触镜（soft contact lens,SCL）和硬性透气性角膜接触镜（rigid gas permeable contact lense,RGPCL）对角膜形态参数的影响。方法　收集视光学中心验配角膜接触镜的屈光不正患者60例(120眼),按照患者配戴SCL或RGPCL分为SCL组和RGPCL组（两组均为30例60眼）,在戴镜前及戴镜后1 a、2 a测量2组患者中央角膜厚度、内皮细胞密度、六角形细胞比例及变异系数,并对2组数据进行对比。结果　SCL组:戴镜后2 a,中央角膜厚度(509±31)μm较戴镜前(549±26)μm明显下降（P<0.05）;角膜内皮细胞密度为(2819.3±169.2）个·mm^-2,较戴镜前密度(3182.6±162.3）个·mm^-2减少;六角形细胞比例（51.52±4.69）%较戴镜前（61.45±4.58）%降低（P<0.05）;内皮细胞变异系数（39.14±3.15）较戴镜前（33.47±2.83）增加（P<0.05）。RGPCL组戴镜前后中央角膜厚度、角膜内皮细胞密度、六角形细胞比例及内皮细胞变异系数比较,差异均无统计学意义（均为P>0.05）。结论　与配戴SCL相比,配戴RGPCL对屈光不正患者的角膜形态和功能影响不明显,更适合长期配戴。     

青少年近视性屈光参差配戴角膜塑形镜的临床效果

目的：观察青少年近视性屈光参差配戴角膜塑形镜的临床效果。方法：回顾性队列研究。收集浙江大学医学院附属第二医院眼科中心从2015年12月至2017年6月之间开始配戴角膜塑形镜的患者32例,年龄8～16（11.2±2.2）岁,随访时间2年。双眼等效球镜屈光度差值≥1.00 D,滴用睫状肌麻痹剂后的等效球镜度范围为-0.75～-6.00 D。患者分为高屈光度眼组（两眼中屈光度较高眼）和低屈光度眼组（两眼中屈光度较低眼）,每组32眼,均配戴角膜塑形镜。观察双眼戴镜前以及戴镜后半年、1年、1.5年,2年的眼轴变化。数据采用配对t检验进行比较。结果：双眼眼轴差值由戴镜前（0.46±0.24 mm） 下降到戴镜2年后（0.33±0.28 mm）,差异有统计学意义（t=5.038,P<0.001）,高屈光度眼组戴镜2年后眼轴变化量（0.38±0.21）mm小于低屈光度眼组眼轴变化量（0.51±0.26 mm）,差异有统计学意义（t=6.52,P<0.001）。结论：青少年长期配戴角膜塑形镜可以减小近视性屈光参差双眼之间的眼轴差值,减少屈光参差量,可以更有效减缓近视屈光度较高眼的眼轴增长,配戴角膜塑形镜是改善屈光参差的一种有效方式。     

长期配戴角膜接触镜对角膜形态的影响

目的 比较分析长期配戴软性角膜接触镜（SCL）及硬性透气性角膜接触镜（RGPCL）患者的中央角膜厚度（CCT）、角膜曲率及角膜内皮细胞形态之间的差别.方法 选取有角膜接触镜配戴适应证的屈光不正患者共172例（300眼）,除屈光不正外无其他任何眼病.根据患者的主观要求及眼部情况分为SCL配戴组（59例102眼）和RGPCL配戴组（113例198眼）.配戴方法均为日戴型连续配戴,即每日戴镜时间不少于6 h.随访时间为3年.分别于配戴前、配戴后6个月和3年进行检查,采用非接触式角膜内皮镜测量CCT、角膜内皮细胞计数、六角形比例及变异系数,采用电脑验光仪测量角膜曲率.对两组戴镜前后的各参数进行配对t检验,组间比较采用两独立样本t检验.结果 中央角膜厚度：戴镜后3年,SCL组CCT较戴镜前减少（27.1±0.8）mm,差异有统计学意义（P＜0.05）;RGPCL组CCT较戴镜前减少（3.1±2.2）mm,差异无统计学意义（P＞0.05）;两组间比较,戴镜前和戴镜后6个月时CCT差异无统计学意义,但在戴镜后3年时RGPCL组CTT较SCL组厚,两组差异有统计学意义（P＜0.05）.角膜曲率：SCL组戴镜后各时间点水平曲率和垂直曲率与术前比较,差异均无统计学意义;RGPCL组戴镜后各时间点与戴镜前比较,差异均有统计学意义（P＜0.05）;两组间比较,戴镜后3年RGPCL组角膜曲率较SCL组小,两组差异有统计学意义（P＜0.05）.角膜内皮细胞密度：SCL组和RGPCL组戴镜后角膜内皮细胞密度较戴镜前均有降低,差异均有统计学意义.戴镜后3年,SCL组和RGPCL组角膜内皮细胞密度分别降低了（368.5±31.5）个/mm^2和（140.2±5.6）个/mm^2,差异有统计学意义（P＜0.05）.六角形比例和变异系数：SCL组戴镜后3年与戴镜前比较,差异有统计学意义（P＜0.05）;RGPCL组戴镜前后变化不明显;两组间比较,戴镜后3年两组差异有统计学意义（P＜0.05）.结论 长期配戴RGPCL对患者角膜形态及功能的影响较小,同长期配戴SCL相比具有更高的安全性.     

近视屈光度数与角膜屈光力和非球面系数的相关性

目的：对不同近视屈光状态下人眼角膜总屈光力、后表面屈光力、眼轴、角膜非球面参数 Q 值、中央角膜厚度（central cornea thickness, CCT）及眼压进行测量,并探讨近视度数与上述相关参数的关系。 方法：近视患者138例138眼（所有患者选择右眼进行分析）,根据综合验光仪测量的近视度数,患者分为三组：低度近视组（-1.00D～-3.00D）,中度近视组（-3.25D～-6.00D）,高度近视组（〉-6.00D）。各眼使用Pentacam眼前节分析仪（德国,Oculus公司）进行检测,获得角膜总屈光力和后表面屈光力以及Q值,使用非接触式眼压测量仪（日本Canon公司）测量眼压,使用 A 超测量仪（美国Tomey公司AL-3000）测量中央角膜厚度（CCT）和眼轴长度。数据采用Pearson相关性分析、单因素方差分析进行处理。 结果：近视度数与眼轴呈负相关（r=-0.682, P〈0.001）,与角膜屈光力无相关性（r=0.009, P=0.925）,眼轴与角膜屈光力呈负相关（r=-0.554, P〈0.001）。近视度数与Q值呈正相关（r=0.674, P〈0.001）,Q值与眼压成呈负相关（ r=-0.375, P=0.01）。近视度数与CCT及眼压无相关性（ r=-0.138, P=0.141;r=-0.121, P=0.157）。 结论：角膜屈光力在近视发展过程中有正视化作用,Q值与近视度数及眼压的相关关系对指导角膜屈光手术有临床意义。     

屈光参差儿童单眼配戴角膜塑形镜的临床效果

目的：评估屈光参差儿童单眼配戴角膜塑形镜控制近视、矫正屈光参差的临床效果。方法：回顾性自身对照病例研究。收集2014 年1 月至2016 年12 月在温州医科大学附属眼视光医院单眼接受角膜塑形镜治疗的屈光参差儿童40 例,年龄9～15 岁,随访时间1 年。双眼根据是否配戴角膜塑形镜分为配戴角膜塑形镜眼组（戴镜眼组）和未配戴角膜塑形镜眼组（未戴镜眼组）。戴镜眼组40眼,等效球镜度（-2.51±0.95）D;未戴镜眼组40眼,等效球镜度（0.10±0.52）D。双眼屈光度数差异范围1.00～4.38 D,平均（2.61±1.04）D。观察戴镜前及戴镜1 年后的双眼裸眼视力（UCVA）、屈光度数、眼轴、前房深度及角膜形态参数等变化,并对数据进行配对t检验和Pearson相关分析。结果：单眼配戴角膜塑形镜1年后,双眼UCVA（LogMAR）差值由0.77±0.29下降至0.17±0.22（t=-15.865,P < 0.001）,双眼屈光度数的差值由（2.61±1.04）D下降至（2.07±1.05）D（t=-7.366,P < 0.001）,双眼眼轴的差值由（0.97±0.66）mm降至（0.67±0.63）mm（t=-5.995,P < 0.001）,双眼前房深度的差值由（0.47±0.11）mm下降至（0.01±0.13）mm（t=-2.704,P=0.027）。相关性分析发现戴镜后屈光参差减少量仅与双眼眼轴差值变化量、双眼UCVA差值变化量具有相关性（r=0.539、0.418,P < 0.001）。结论：单眼配戴角膜塑形镜对屈光参差儿童是一种安全、有效的控制近视进展、矫正屈光参差的临床方法。     

应用共聚焦显微镜评价角膜接触镜对SBK术后角膜神经再生的影响

目的利用活体共聚焦显微镜（IVCM）观察配戴角膜接触镜对前弹力层下激光角膜磨镶术（SBK）后角膜基底下神经纤维（CSNFs）修复的影响,探讨IVCM在评价屈光手术神经损伤修复中的价值。方法前瞻性队列研究。选择2010年5月至2011年6月在北京同仁眼科中心行SBK术患者43例（86眼）,年龄18~35岁,屈光度-2.75~-10.00 D,部分患者术前均配戴过软性角膜接触镜。将患者分为4组：组I,戴镜时间≤5年,共10例;组II,戴镜时间＞5~10年,共6例;组III,戴镜时间大于＞10年,共4例;组IV（对照组）,无角膜接触镜配戴史,共23例。分别于术前,术后1、3、6个月采用IVCM观察CSNFs的密度、数量级弯曲度,并通过评分评价CSNFs再生速度。数据采用独立样本t检验、单因素方差分析和χ2检验进行统计分析。结果术前不同戴镜时间患者角膜中央CSNFs密度、数量及弯曲度比较差异无统计学意义（F=1.042、1.947、0.821,P＞0.05）,但配戴时间大于10年的患者神经密度和数量较低,弯曲度较高。术后6个月角膜中央再生CSNFs密度、数量明显低于术前,弯曲度高于术前（t=6.150、-4.141、9.709,P＜0.01）。术后6个月不同戴镜时间组角膜中央再生CSNFs密度、数量及弯曲度差异无统计学意义（F=1.472、0.318、0.353,P＞0.05）,但随戴镜时间延长,数量和密度下降,弯曲度增高;不同戴镜时间对SBK术后CSNFs再生速度的影响差异无统计学意义（χ2=4.273、8.806、5.364,P＞0.05）,但配戴角膜接触镜大于10年患者术后3和6个月再生CSNFs进入角膜中央3 mm区域的比例低于其他各组。结论配戴角膜接触镜时间对SBK术前后CSNFs无显著影响,但长时间配戴可延缓术后CSNFs的修复。IVCM可客观、定量评价SBK术后角膜神经的损伤与修复。     

青少年高度近视眼患者长期配戴角膜塑形镜的效果观察

目的：探讨角膜塑形镜矫正青少年高度近视眼的效果。方法回顾性研究。选择配戴角膜塑形镜的青少年高度近视眼患者30例,平均年龄为（15±2）岁,平均球镜度数（-7.34±0.91）D,平均裸眼视力0.89±0.29（LogMAR视力表）;平坦角膜曲率（43.54±1.16）D;平均眼轴长度（26.38±0.94）mm。根据屈光及眼部检查结果配戴角膜塑形镜,并按屈光不正程度选择日戴和夜戴两种配戴方式。观察戴镜6个月及1、2、3、4、5年的摘镜视力、平坦角膜曲率、球镜度数及眼轴长度与配戴前的变化。戴镜前后各参数比较采用单因素方差分析,两两比较采用单因素方差分析的多重比较分析,不同配戴方式的戴镜前后同一时间比较采用成组t检验。结果30例高度近视眼患者配戴角膜塑形镜5年期间,裸眼视力及角膜曲率戴镜后较戴镜前变化明显,裸眼视力在戴镜后较戴镜前均有不同程度提高（各观察点LogMAR视力为0.45±0.31、0.49±0.32、0.43±0.30、0.47±0.31、0.58±0.35、0.53±0.27;F=10.725,P=0.000）,角膜曲率较戴镜前趋于平坦（5年观察期角膜曲率分别为41.14±1.54、41.75±1.88、41.54±2.10、41.73±1.89、41.94±1.61、40.70±1.67;F=10.161,P=0.000）,屈光度数在戴镜前2年间较戴镜前下降明显,后期观察与配镜前无明显差异性变化（观察期间屈光度分别为-5.23±1.81、-5.59±2.75、-6.29±2.12、-6.63±2.31、-6.83±2.33、-7.01±1.81;F=4.929,P=0.000）,屈光度维持较稳定。眼轴仅戴镜第5年的变化稍有增长,其余不同戴镜时间段与配戴前比较差异无无统计学意义（5年期间眼轴变化分别为26.41±0.90、26.68±0.93、26.69±1.06、26.75±0.94、26.81±1.04、27.04±1.01;F=1.831,P=0.094）,眼轴增长控制理想。戴镜期间所有患者均未出现严重的并发症而导致放弃配戴。结论高度近视眼患者配戴角膜塑形镜5年控制近视效果明显,未见严重的并发症。（中华眼科杂志,2015,51：515-519）     

Rigid gas-permeable contact lens fitting in LASIK patients for the correction of multifocal corneas

BACKGROUND: Laser in situ keratomileusis (LASIK) has recently become the most commonly performed refractive surgery procedure. Results are promising in correcting low to moderate myopia. Most complications occur during the surgeon's learning curve. One of the complications is a decentration of the ablated area that causes monocular diplopia and a nocturnal halo phenomenon due to a multifocality of the corneal surface overlying the entrance pupil. The corneal shape is significantly altered after LASIK. We evaluate the efficacy of rigid gas-permeable contact lens designs and fitting techniques used in eight eyes with multifocal LASIK ablations to correct haloes and impaired night vision complaints. METHODS: We used large-diameter tetra-curved rigid gas-permeable (RGP) contact lenses for visual recovery in eight eyes of seven LASIK patients. We used the power on the transition zone of the corneal topographic map, 0.2 mm outside the ablated refractive area, for selection of the back optic zone radius of the RGP contact lenses. Procedures for lens fitting are described. Visual acuity (high-contrast logarithm of the minimum angle of resolution, LogMAR) was measured before- and 6 months after contact lens fitting. RESULTS: Large-diameter tetra-curve RGP lenses with a mean diameter of 11.85 (SD 0.16) mm were successfully used in LASIK patients with multifocal corneas. Mean best spectacle-corrected visual acuity was +0.3 LogMAR (SD 0.19; in Snellen equivalent, 20/40) and improved significantly with the contact lenses to +0.08 LogMAR (SD 0.11; in Snellen equivalent, 20/25, P=<0.01). During the follow-up period of 16.7 months, the average daily wearing time of the lenses was 12.5 h. Contact lenses with a standard geometry were not useful due to excessive movement and inadequate centration. CONCLUSIONS: Contact lenses with large diameters, in combination with selection of the back optic zone radius 0.2 mm peripheral of the refractive ablation zone, facilitate contact lens fitting to restore best-corrected visual acuity in LASIK patients with multifocal corneas.     

配戴角膜塑形镜后镜片偏心的两种测量方法比较

目的：:对比分析配戴角膜塑形镜后2种镜片偏心的测量方法。方法：:回顾性临床研究。选取2016年8月至2018年10月在温州医科大学附属眼视光医院完成角膜塑形镜验配并持续戴镜24个月的近视儿童77例,将戴镜前和戴镜3个月后的角膜地形图对比构建切向差异图,分析戴镜前和戴镜3个月后Kappa角距离的变化情况,然后通过MATL...     

Silicone hydrogel mini‐scleral contact lenses in early stage after corneal collagen cross‐linking for keratoconus: a retrospective case series

Background : The aim was to the evaluate performance of a novel silicone hydrogel mini‐scleral contact lens (SHmS) for optical correction of keratoconus in the early stages after the corneal collagen cross‐linking procedure (CXL). Methods : We retrospectively analysed the visual acuity improvement and corneal adaptation in the first 10 eyes of nine patients fitted with SHmS lenses one to 3.5 months after corneal collagen cross‐linking. The lenses were designed to rest over the patients’ sclera and peri‐limbal cornea and vault the central cornea with minimal support over it. Visual acuities with manifest refraction and contact lenses, refractive and topographical values (Kmin and Kmax) were evaluated on lens dispensing and after six month of lens wearing. Ocular physiological responses were evaluated using the Institute of Eye Research (IER) grading scales. Results : SHmS fitting was performed 2.1 ± 0.97 (SD) months after collagen cross‐linking. Mean follow up was 10.9 ± 4.41 months (range six to 18 months). Mean decimal visual acuity with SHmS was 0.66 ± 0.22 (approximately 6/9 Snellen fraction, range 0.3 to 0.1) or 0.75 ± 0.14 (approximately 6/8.1, range 0.5 to 1.0), when omitting two amblyopic eyes. Nine (90 per cent) eyes were successfully fitted, that is, able to wear the lenses for 10 hours per day or longer. Mean wearing time was 11.7 hours (range six to 14) per day. No corneal neovascularisation or papillary reaction was found in all fitted eyes. Conclusions : SHmS contact lenses provide successful visual rehabilitation shortly after corneal collagen cross‐linking. This new soft contact lens design with scleral fixation and minimal apical touch was demonstrated to be safe shortly after collagen cross‐linking, as the avoidance of contact with the treated zone minimises contact lens influence on corneal recovery.     

Rigid contact lens fitting relationships in keratoconus. Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study Group.

PURPOSE: Although the influence of flat-fitting contact lenses on corneal scarring in keratoconus is frequently debated, the current standard of care with regard to the apical fitting relationship in keratoconus remains undocumented. METHODS: Patients were examined at baseline in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study (N = 1209). Patients wearing a rigid contact lens in one or both eyes (N = 808) had their habitual rigid contact lenses analyzed, and the fluorescein patterns and base curves were compared to the first definite apical clearance lens (FDACL). The FDACL is the flattest lens in the CLEK Study trial lens set that exhibits an apical clearance fluorescein pattern. For patients wearing a rigid contact lens in both eyes, one eye was selected randomly for analysis. RESULTS: Twelve percent of the rigid contact lens-wearing eyes were wearing lenses fitted with apical clearance based upon the clinician's fluorescein pattern interpretation. The remainder (88%) was wearing lenses fitted with apical touch. For mild (steep keratometric reading <45 D) keratoconus corneas, the mean estimate of the base curve to cornea-fitting relationship was 1.18 D flat (SD +/- 1.84 D); moderate (steep keratometric reading: 45 to 52 D) corneas were fitted on average 2.38 D flat (SD +/- 2.56 D); and severe (steep keratometric reading > 52 D) corneas were fitted an average of 4.01 D flat (SD +/- 4.11 D). CONCLUSIONS: Despite the potential risk for corneal scarring imposed by flat-fitting rigid contact lenses, most CLEK Study patients wear flat-fitting lenses. Overall, rigid lenses were fitted an average of 2.86 D (SD +/- 3.31 D) flatter than the FDACL.     

高度近视儿童青少年配戴多焦点软性接触镜延缓近视进展的有效性研究

目的　评估高度近视儿童青少年配戴多焦点软性亲水性接触镜延缓近视进展的有效性。方法　回顾性研究。纳入2018年11月到2020年2月于天津市眼科医院视光中心配戴多焦点软性亲水性接触镜的近视儿童青少年36例和配戴单光框架眼镜者36例（均选取右眼）,年龄为8~15岁,等效球镜度（SE）为-5.00~-10.00 D。记录患者年龄、性别等信息,收集患者基线及戴镜1年后的主觉屈光度、眼轴长度等指标。采用独立样本t检验分析两组患者基线与1年后的SE变化量及眼轴长度变化量,采用多元线性回归分析影响屈光度及眼轴长度变化的因素,二元Logistic回归分析影响进展性近视发展的因素。结果　配戴多焦点软性亲水性接触镜组患儿与单光框架眼镜组患儿相比,两组间1年的SE变化量及眼轴长度变化量差异均有统计学意义（t=5.407,P<0.001;t=-2.763,P=0.007）。多元线性回归分析发现,SE进展的主要影响因素是戴镜组别和基线眼轴长度,回归方程:SE=3.982+0.458×戴镜组别-0.138×基线眼轴长度（R²=0.375,调整R²=0.357）;眼轴变化主要影响因素为戴镜组别,回归方程:AL=0.116+0.120×戴镜组别（R²=0.097,调整R²=0.097）。对于是否成为进展性近视儿童来说,配戴单光框架眼镜组的风险是多焦点软镜的12.571倍。结论　高度近视儿童青少年配戴多焦点软性接触镜能延缓近视进展（65.4%）及眼轴生长（33.3%）。     

The effects of long-term contact lens wear on corneal thickness, curvature, and surface regularity

PURPOSE: To evaluate the effect of long-term contact lens wear on corneal thickness, curvature, and surface regularity. DESIGN: A prospective, clinic-based, case-control study. PARTICIPANTS: A total of 40 eyes of 20 normal subjects and 64 eyes of 35 subjects wearing contact lenses for more than 5 years were evaluated. METHODS: The Orbscan Corneal Topography System was used to evaluate the entire corneal thickness and curvature, anterior curvature and the anterior and posterior elevation topographic patterns in normal eyes and subjects wearing contact lenses on a regular basis for more than 5 years. Indices of TMS-1 Corneal Topography System were used to determine corneal surface regularity in subjects wearing contact lenses and normal eyes. All topographic examinations were performed after contact lenses had been removed for at least 2 weeks. MAIN OUTCOME MEASURES: The entire corneal thickness, curvature, surface regularity index (SRI), surface asymmetry index (SAI), potential visual acuity (PVA) and topographic patterns were compared between normal eyes and subjects wearing contact lenses for more than 5 years. RESULTS: The 64 eyes of 35 subjects evaluated by the Orbscan instrument had an average of 13.45 +/- 6.42 years of contact lens wear. The mean corneal thickness in the center and in eight peripheral areas measured in contact lens wearing subjects was significantly reduced by about 30 to 50 microm compared to normal subjects (P < 0.001 for central and peripheral sites). No correlation was noted between central corneal thickness and degree of myopia in diopters (r = 0.15, 0.10 < P < 0.25). The corneal curvature, maximum keratometry (Max K) and minimum keratometry (Min K) readings, were significantly steeper in eyes wearing contact lenses than normal eyes (P < 0.01 for Max K and Min K measured by both instruments). No difference in the mean corneal astigmatism was noted between groups. The SRI and SAI, but not the PVA index, of the TMS-1 were significantly greater in contact lens wearers than in the control group (P < 0.01 for both SRI and SAI, P = 0.15 for PVA). The color-coded patterns of all curvature and elevation maps made with both instruments showed no significant difference between subjects wearing contact lenses and the control group. There was no significant difference between corneal curvature measurements taken with the Orbscan System or the TMS-1 System in both normal and contact lens groups. CONCLUSIONS: Long-term contact lens wear appears to decrease the entire corneal thickness and increase the corneal curvature and surface irregularity.     

Variables affecting rigid contact lens comfort in the collaborative longitudinal evaluation of keratoconus (CLEK) study.

PURPOSE: To identify factors associated with rigid contact lens comfort in keratoconus. METHODS: Baseline data from the 16 Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study clinical sites were analyzed for all patients wearing a rigid contact lens in their more severely keratoconic eye (as determined by steep keratometry). Corneal transplant patients, patients who did not wear a rigid contact lens in either eye, patients who did not wear a rigid lens in their worse eye, and patients with missing contact lens comfort data were excluded from the sample. A total of 751 eyes were included. Variables assessed included measures of disease severity, visual acuity through the patients' habitual rigid contact lenses, contact lens wearing time, the apical fitting relationship of the contact lens, the degree of peripheral clearance, and the presence of corneal scarring and staining. Comfort was measured by asking the patients "In general, how comfortable are your contact lenses?" (1 = very comfortable through 5 = very irritating). RESULTS: Measures of disease severity (steep keratometry and the first definite apical clearance lens) were not associated with lens comfort. There was no difference in self-reported contact lens comfort between patients fitted with apical touch vs. apical clearance. Patients with a peripheral clearance rating of "minimal unacceptable" (more common among patients with milder keratoconus) were approximately half as likely to report good contact lens comfort compared with patients with "average" peripheral clearance (unadjusted odds ratio, 0.39; 95% confidence interval, 0.19 to 0.79). There was no association between contact lens comfort and the other peripheral clearance ratings compared with ratings of average. CONCLUSIONS: There does not appear to be an association between decreasing patient-reported rigid lens comfort and increasing disease severity as measured by steep keratometry or first definite apical clearance lens in this sample. The apical fitting relationship (flat vs. steep) does not appear to be associated with patient-reported comfort. Minimal peripheral clearance may contribute to decreased rigid contact lens comfort in keratoconus.     

Effect of peripheral defocus on axial growth and modulation of refractive error in children with anisohyperopia

Purpose

To establish whether axial growth and refractive error can be modulated in anisohyperopic children by imposing relative peripheral hyperopic defocus (RPHD) using multifocal soft contact lenses.

Methods

This study is a prospective, controlled paired-eye study with anisohyperopic children. Axial growth and refractive error were observed without intervention for the first 6 months of the 3-year trial with participants wearing single vision spectacles. Then, participants wore a centre-near, multifocal, soft contact lens (+2.00 D add) in their more hyperopic eye for 2 years, with a single vision contact lens worn in the fellow eye if required. The ‘centre-near’ portion of the contact lens in the more hyperopic eye corrected distance refractive error while the ‘distance’ portion imposed hyperopic defocus in the peripheral retina. Participants reverted to single vision spectacles for the final 6 months.

Results

Eleven participants, mean age of 10.56 years (SD 1.43; range 8.25–13.42), completed the trial. No increase in axial length (AL) was found during the first 6 months in either eye (p > 0.99). Axial growth across the 2-year intervention period was 0.11 mm (SEM 0.03; p = 0.06) in the test eye versus 0.15 mm (SEM 0.03; p = 0.003) in the control eye. AL was invariant during the final 6 months in both eyes (p > 0.99). Refractive error was stable during the first 6 months in both eyes (p = 0.71). Refractive error change across the 2-year intervention period was −0.23 D (SEM 0.14; p = 0.32) in the test eye versus −0.30 D (SEM 0.14; p = 0.61) in the control eye. Neither eye demonstrated a change in refractive error during the final 6 months (p > 0.99).

Conclusions

Imposing RPHD using the centre-near, multifocal, contact lens specified here did not accelerate axial growth nor reduce refractive error in anisohyperopic children.