青少年近视配戴角膜塑形镜前后眼轴长度的变化

目的：观察青少年近视配戴角膜塑形镜前后眼轴长度的变化。

方法：选取2014-07/2017-10在西安交通大学第一附属医院眼视光中心配戴角膜塑形镜的8～16岁青少年近视102例为研究对象,观察其戴镜后1、2、3a眼轴变化情况,对研究对象的右眼数据进行统计分析。

结果：青少年近视102例配戴角膜塑形镜3a后,眼轴增长0.42±0.37mm,低、中、高度近视组眼轴分别增长0.65±0.35、0.32±0.37、0.30±0.29mm,高度近视组(夜戴角膜塑形镜联合白天全矫框架眼镜)眼轴增长最慢; 配戴时间与戴镜前屈光度、起始治疗年龄之间均存在交互作用(P<0.001); 而配戴时间和性别之间无交互作用(F=0.292,P=0.695),男、女性戴镜后的眼轴变化速率未见差异。

结论：低、中、高度近视青少年配戴角膜塑形镜后眼轴长度均有增长,高度近视青少年夜间配戴角膜塑形镜联合白天全矫框架眼镜眼轴增长速度慢于低中度近视者。     

角膜塑形镜治疗后光学区偏离中心对控制近视的影响

目的：观察和分析角膜塑形镜治疗后角膜形态的变化,评估角膜塑形镜治疗后光学区偏离中心对控制近视的影响。

方法：回顾性临床研究。对134例134眼近视患儿配戴角膜塑形镜矫治近视,平均年龄10.66±1.79岁, 均取右眼数据进行研究。分别在戴镜前及戴镜后3、6、12、18、24mo检查视力、眼轴和角膜地形图。使用SPSS19.0进行统计学分析。

结果：戴镜后3、6、12、18、24mo的光学区偏瞳孔中心距离分别为0.84±0.45、0.77±0.40、0.79±0.41、0.78±0.41、0.79±0.42mm,差异无统计学意义(F=1.187,P=0.319)。戴镜24mo后平均光学区偏中心距离为0.79±0.35mm,眼轴增长均值为0.32±0.30mm。戴镜24mo后平均偏中心距离轻度(<0.5mm)、中度(0.5～1.0mm)、重度(>1.0mm)的眼轴增长分别为0.45±0.34、0.32±0.28、0.23±0.29mm,差异有统计学意义(F=3.825,P=0.024)。戴镜后的平均偏中心距离和眼轴增长经线性回归分析,其线性关系有统计学意义(F=7.246,P=0.008),线性回归方程Y=0.478-0.194X。戴镜24mo后,18眼有重影,其偏中心距离均值1.18±0.36mm; 116眼无重影,其偏中心距离均值0.73±0.31mm,偏中心距离比较差异有统计学意义(t=5.59,P<0.01)。

结论：光学区偏中心距离在角膜塑形镜治疗3mo后趋于稳定,且对控制近视的效果和视觉质量有影响。     

角膜塑形镜控制青少年单眼近视的临床观察

目的：观察角膜塑形镜控制青少年单眼近视的临床效果。

方法：选取2014-06/2016-03于我院视光门诊单眼验配角膜塑形镜的单眼近视患者56例112眼,将配戴角膜塑形镜的眼作为试验组,未作处理的另一眼作为对照组。观察戴镜前和戴镜12mo后屈光度、角膜曲率、眼轴长度变化情况。

结果：戴镜12mo后,试验组屈光度增加量(0.29±0.15D)与对照组(0.76±0.41D)差异显著(t=2.8631,P<0.001); 试验组水平角膜曲率变化量(0.27±0.11D)与对照组(0.20±0.14D)无差异(t=0.8204,P>0.05); 试验组眼轴长度增加量(0.14±0.10mm)与对照组(0.32±0.14mm)差异显著(t=2.7518,P<0.001)。

结论：角膜塑形镜可通过减缓眼轴增长来控制近视度数的增加,从而延缓近视的发展。     

低浓度阿托品联合角膜塑形镜矫治近视的临床观察

目的：观察低浓度阿托品滴眼液联合角膜塑形镜治疗青少年低中度近视的有效性及安全性。

方法：选取2016-05/2018-08于我院就诊的青少年低中度近视患者126例126眼(均取右眼数据),使用夜戴型角膜塑形镜1mo后随机进行分组,试验组患者63眼每晚联合应用低浓度(0.01%)阿托品滴眼液1次,对照组患者63眼每晚联合应用聚乙二醇滴眼液1次。随访观察眼轴、等效球镜度、最佳矫正近视力、瞳孔直径、调节幅度、泪膜破裂时间、眼压的情况。

结果：联合治疗1a,试验组和对照组低度近视患者眼轴分别增长0.13±0.03、0.22±0.05mm,中度近视患者眼轴分别增长0.12±0.03、0.20±0.05mm; 低度近视患者等效球镜度分别增加0.16±0.07、0.21±0.08D,中度近视患者等效球镜度分别增加0.16±0.05、0.20±0.09D,两组之间眼轴和等效球镜度变化均有差异(均P<0.05)。治疗1a后,两组患者最佳矫正近视力、泪膜破裂时间、眼压均无差异(P>0.05),但试验组患者瞳孔直径较对照组明显增大,调节幅度较对照组降低(P<0.05)。

结论：0.01%阿托品滴眼液联合角膜塑形镜能更有效控制青少年近视进展,且安全有效。     

角膜塑形镜矫正近视对角膜形态的变化及影响

目的：探讨配戴角膜塑形镜矫正近视对角膜形态的变化及影响。

方法：选择2015-01/2016-12期间在我院接受配戴角膜塑形镜矫正近视的90例患者为研究对象,根据配戴方式不同分为观察组(夜戴)45例90眼和对照组(日戴)45例90眼,观察比较两组患者配戴角膜塑形镜前、配戴后1wk,1、3、6mo时的等效球镜度(spherical equivalent,SE)、裸眼视力(uncorrected visual acuity,UCVA)、角膜曲率及角膜中央厚度。

结果：两组患者在戴镜后1wk,1、3、6mo时测量角膜中央厚度均明显低于戴镜前,差异有统计学意义(P<0.05); 观察组在戴镜后1、3、6mo时测量角膜中央厚度均明显低于对照组,差异有统计学意义(P<0.05); 两组患者配戴角膜塑形镜后1wk,1、3、6mo时的角膜曲率值均明显低于本组配戴角膜塑形镜前,且配戴前后差异具有统计学意义(P<0.05)。观察组配戴角膜塑形镜6mo时的角膜曲率(40.0±0.5D)明显低于对照组配戴角膜塑形镜6mo时的角膜曲率(41.3±0.9D),且组间差异具有统计学意义(P<0.05); 在戴镜3mo时观察角膜上皮染色率,观察组上皮染色率阳性占49%(44/90),对照组上皮染色率阳性占29%(26/90),两组均以0级、1级为主; 随着角膜塑形镜配戴时间延长,两组患者的SE水平都呈下降趋势,且均明显低于配戴之前。配戴6mo时观察组SE水平(-0.42±0.20D)明显低于对照组SE水平(-0.52±0.19D),差异具有统计学意义(P<0.05); 两组患者配戴角膜塑形镜后UCVA值明显升高,且与配戴前相比差异具有统计学意义(P<0.05)。

结论：配戴角膜塑形镜可降低近视度数,提高视力,且夜间配戴效果相对优于白天配戴。     

环曲面与球面角膜塑形镜控制青少年中低度近视的效果比较

目的：比较环曲面和球面角膜塑形镜对青少年中低度近视的控制效果。

方法：回顾性分析2020-07/2021-06于上海德目佳苑眼科门诊部就诊并验配角膜塑形镜的中低度青少年近视患者169例290眼的临床资料，根据配戴的角膜塑形镜类型分为环曲面组(81例135眼)和球面组(88例155眼)。记录治疗前后视力和眼轴变化情况，评估治疗效果。

结果：治疗后1a，环曲面组和球面组患者裸眼视力均较治疗前改善(P<0.01)，眼轴均较治疗前有所增长(P<0.01)，但两组间裸眼视力(0.014±0.043、0.017±0.047LogMAR)和眼轴增长量(0.18±0.22、0.19±0.22mm)均无显著差异(P>0.05)。

结论：环曲面和球面角膜塑形镜均可提升中低度近视青少年裸眼视力，近视控制效果无显著差异。     

CRT与VST设计角膜塑形镜对低E值角膜形态近视的控制效果比较

目的：观察和分析配戴CRT与VST设计角膜塑形镜对低E值角膜形态控制青少年近视发展的有效性及安全性的对比研究。

方法：前瞻性研究，选取2020-01/2021-12于我院视光门诊就诊配戴角膜塑形镜的青少年近视患者100例100眼，取右眼数据用于研究。按等效球镜分低度近视组(-1.00--3.00 D)和中度近视组(-3.25--5.00 D)，各50例。组内采用随机数字表法分为CRT组和VST组，各25例。测量各组配戴前后裸眼视力、屈光度、眼轴(AL)、泪膜破裂时间(BUT)、角膜内皮细胞密度、角膜点染分级、镜片偏位情况、MRT 15°-30°处视网膜近视离焦量。随访1.5 a。

结果：低度近视中，CRT组和VST组配戴角膜塑形镜后裸眼视力各时间点无差异，中度近视数组塑形后裸眼视力CRT组优于VST组，两组1 d，1 wk的视力有差异(t=-9.474、-12.067，均P<0.01)，其他时间点两组均无差异。戴镜后6 mo，1.5 a，低度近视、中度近视中CRT组和VST组AL增加量均无差异，但CRT组比VST组增长少。两组戴镜后6 mo，1.5 a的双眼BUT及角膜内皮细胞密度均无差异。从两组的角膜损伤来看CRT组角膜损伤低于VST组，但无差异(Z=-1.803，P=0.071)，CRT组镜片偏位情况优于VST组(Z=-4.629，P<0.001)； MRT 15°-30°处视网膜近视离焦量，低度近视中两组无差异，中度近视中1、3、6 mo离焦量有差异(t=-3.949，P=0.008； t=-5.833，P<0.001； t=-6.231，P<0.001)，CRT组能产生更多的近视性离焦量。

结论：对于对低E值角膜形态的患者，CRT采用角膜8 mm处的矢高值来验配，不局限于角膜E值，塑形更快，塑形后裸眼视力更好，特别对于中度近视能获得更好的白天视力，从控制近视来看，CRT验配中抬高反转区(RZD)，产生小的中央光学区能产生更大的周边近视性离焦，但两组控制眼轴增长之间无明显差异。两组的角膜损伤少，对近视控制安全性一致。     

低浓度阿托品联合角膜塑形镜治疗青少年中低度近视的疗效

目的：分析角膜塑形镜联合低浓度阿托品对青少年中低度近视的控制效果。

方法：选取2016-01/06我科收治的中低度近视青少年患者76例152眼,按照自愿原则分为角膜塑形组36例72眼与角膜塑形镜联合低浓度阿托品组40例80眼(联合组),两组患者均配戴角膜塑形镜,联合组加用0.1g/L阿托品滴眼液点眼,均随访1a,检查戴镜前后裸眼视力、屈光度、眼轴长度、眼压、泪膜功能及角膜各参数的变化,统计并发症发生率。

结果：戴镜前、戴镜1a两组裸眼视力、屈光度、眼轴长度、眼压比较无差异(P>0.05),联合组戴镜前、戴镜1a裸眼视力变化幅度高于角膜塑形镜组,屈光度及眼轴长度差值低于角膜塑形镜组(P<0.05); 戴镜前,两组患者泪膜脂质层厚度(LLT)、客观散射指数(OSI)、泪膜破裂时间(BUT)比较无差异(P>0.05),戴镜1a,联合组LLT、BUT高于角膜塑形镜组,OSI低于角膜塑形镜组(P<0.05); 戴镜前,两组患者角膜曲率、角膜厚度、前房深度比较无差异(P>0.05),戴镜1a,联合组角膜曲率、角膜厚度、前房深度变化幅度均低于角膜塑形镜组(P<0.05); 两组患者并发症发生率比较无差异(P>0.05)。

结论：角膜塑形镜联合低浓度阿托品可改善青少年中低度近视患者裸眼视力,控制屈光度、眼轴增长,对角膜形态及泪膜功能无明显负面影响,安全性高。     

夜戴型角膜塑形镜对近视患者睡眠质量的影响

目的：观察配戴夜戴型角膜塑形镜对近视患者睡眠质量的影响。

方法：选取就诊于福建中医药大学附属人民医院眼科配戴夜戴型角膜塑形镜的近视患者30例58眼为试验组,随机选取同期配戴框架眼镜的近视患者30例60眼作为对照组。所有患者分别于戴镜前和戴镜后1、3mo应用匹茨堡睡眠质量指数量表(Pittsburgh Sleep Quality Index,PSQI)进行睡眠质量评估, 观察比较两组患者的睡眠质量。

结果：试验组患者戴镜前、戴镜后1、3mo等效球镜度数分别为-2.78±0.90、-0.30±0.31、-0.28±0.30D,戴镜后1、3mo分别与戴镜前比较,差异均有统计学意义(P<0.05)。戴镜前、戴镜后1、3mo试验组PSQI评分分别是2.13±1.36、2.47±1.98、1.74±1.39分。试验组与对照组比较,戴镜后3mo主观睡眠质量评分的差异具有统计学意义(P<0.05),而PSQI评分和入睡时间、睡眠时间、睡眠效率、睡眠障碍、催眠药物、日间功能的评分差异均无统计学意义(P>0.05)。

结论：配戴夜戴型角膜塑形镜对近视患者总体睡眠质量无明显影响,在配戴初期患者主观睡眠质量下降。     

角膜塑形镜对青少年近视患儿正相对调节力的影响

目的：观察配戴角膜塑形镜对于青少年近视患儿正相对调节力(PRA)改变的影响。

方法：回顾性病例分析。分析2016-09/2017-12间在我院视光科门诊初次就诊的青少年近视性屈光不正患儿122例244眼。其中选择角膜塑形镜矫正者63例(塑形镜组),选择框架眼镜矫正者59例(框架眼镜组),比较两组患儿治疗前及治疗6mo时双眼PRA的改变情况。

结果：治疗前塑形镜组PRA值-0.83±0.23D,框架眼镜组-0.77±0.24D(t=-1.457,P>0.05)。治疗前塑形镜组眼轴24.84±0.90mm,框架眼镜组24.78±0.86mm(t=0.550,P>0.05)。治疗6mo时塑形镜组PRA值-2.27±0.37D,与治疗前有差异(t=37.070,P<0.001)。治疗6mo时框架眼镜组PRA值-0.83±0.24D,与治疗前无差异(t=1.565,P>0.05)。治疗后塑形镜组PRA优于框架组(t=-25.271,P<0.001)。治疗6mo时塑形镜组眼轴24.86±0.91mm,与治疗前24.84±0.90mm有差异(t=-2.453,P<0.05)。治疗6mo时框架眼镜组眼轴24.97±0.86mm,与治疗前24.78±0.86mm有差异(t=39.135,P<0.001)。治疗6mo时两组眼轴无差异(t=-0.932,P>0.05)。

结论：青少年近视患儿配戴塑形镜相比配戴框架眼镜在治疗6mo时可明显提高其双眼PRA储备,但两者眼轴改变差异不明显。     

The future of clinical trials of myopia control

In the field of myopia control, effective optical or pharmaceutical therapies are now available to patients in many markets. This creates challenges for the conduct of placebo-controlled, randomised clinical trials, including ethics, recruitment, retention, selective loss of faster progressors and non-protocol treatments:

1. Ethics: It is valid to question whether withholding treatment in control subjects is ethical.
2. Recruitment: Availability of treatments is making recruitment into clinical trials more difficult.
3. Retention: If masking is not possible, parents may immediately withdraw their child if randomised to no treatment.
4. Selective loss: Withdrawal of fast progressors in the control group leading to a control group biased towards low progression.
5. Non-protocol treatment: Parents may access other myopia treatments in addition to those within the trial.

We propose that future trials may adopt one of the following designs:

1. Non-inferiority trials using an approved drug or device as the control. The choice will depend on whether a regulatory agency has approved the drug or device.
2. Short conventional efficacy trials where data are subsequently entered into a model created from previous clinical trials, which allows robust prediction of long-term treatment efficacy from the initial efficacy.
3. Virtual control group trials based on data relating to axial elongation, myopia progression or both, accounting for subject's age and race.
4. Short-term control data from a cohort, for example, 1 year or less, and applying an appropriate, proportional annual reduction in axial elongation to that population and extrapolating to subsequent years.
5. Time-to-treatment-failure trials using survival analysis; once a treated or control subject progresses or elongates by a given amount, they exit the study and can be offered treatment.

In summary, the future development of new treatments in myopia control will be hampered if significant changes are not made to the design of clinical trials in this area.     

近视回归镜控制青少年近视发展的临床观察

目的:临床观察近视回归镜对青少年近视发展的防治作用。方法:随机选取52例在我院视光中心就诊的年龄在9~18岁近视患者配戴近视回归镜作为治疗组,观察裸眼视力变化,屈光度变化,眼轴长度及角膜曲率变化情况.并与52例年龄及屈光度相似的近视患者配戴框架眼镜作为对照组,观察时间12mo。结果:治疗组屈光度增加<0.50D者38例(76眼)有效率73.1%,对照组屈光度增加<0.50D者18例(36眼)有效率34.6%,两组间有显著差异(P<0.01);治疗组裸眼视力下降<2行者39例(78眼)有效率73.6%,对照组裸眼视力下降<2行者10例(20眼)有效率19.2%,两组间差异有显著性(P<0.05);眼轴长度及角膜曲率值变化治疗组与对照组之间无明显差别。结论:近视回归镜对青少年近视发展有延缓作用。     

Choroidal Thickness and Its Association With Age,Axial Length,and Refractive Error in Chinese Adults

PurposeTo identify the association between the choroidal thickness (ChT) with age and axial length (AL) under different refractive errors (REs) in Chinese adults.MethodsSwept-source optical coherence tomography was used to measure ChT in 2126 right eyes of 2126 participants. The participants were classified as having pathologic myopia (PM), high myopia without PM (HM), low myopia (LM), and nonmyopia (non-M) according to their REs and META-PM (the Meta-Analysis of Pathologic Myopia) classification criteria.ResultsThe mean age was 52.49 ± 20.39 years (range, 18−93 years), and the mean RE was −5.27 ± 5.37 diopters (D; range, −25.5 to +7.75 D). The mean average ChT was 159.25 ± 80.75 µm and decreased in a linear relationship from non-M to PM (190.04 ± 72.64 µm to 60.99 ± 37.58 µm, P < 0.001). A significant decline in ChT was noted between 50 and 70 years (r = −0.302, P < 0.001) and less rapidly after the age of 70 years (r = −0.105, P = 0.024). No correlation was noted between age and ChT under 50 years (P = 0.260). A significantly higher association with AL was noted in the central fovea (β^HM = −23.92, β^LM = −23.88, β^Non-M = −18.80, all P < 0.001) and parafoveal ChT (β^HM = −22.87, β^LM = −22.31, β^Non-M = −18.61, all P < 0.001) when compared with the perifoveal region (β^HM = −19.80, β^LM = −18.29, β^Non-M = −13.95, all P < 0.001). Within each group of PM, HM, LM, and non-M, regression analysis showed that the coefficients of age and AL with different macular regions of ChT varied significantly.ConclusionsChT was negatively correlated with age after 50 years. The thinning of the choroid was more prominent in the center and parafoveal regions as AL increased. Varied distributions of ChT decrease associated with AL and age were noted among different refractive groups.     

角膜塑形术联合框架眼镜矫正青少年高度近视的疗效

目的：观察并探讨角膜塑形术联合框架眼镜对青少年高度近视的矫正和控制效果。方法：选取青少年高度近视患者36例69眼,年龄9~15岁,等效球镜≧-6.00D,球镜度数≧-5.50D,夜间戴四区五弧设计的OK镜,目标降度( TP )=5.00 D。戴OK镜至少1 mo后,残余度数稳定后予框架眼镜矫正。随访观察2a的裸眼视力、屈光度、眼轴长度以及角膜健康状况。结果：(1)裸眼视力的变化：矫正前的裸眼视力为0.09±0.05,矫正1夜;1wk;1,3mo 后裸眼视力分别为0.27±0.14,0.54±0.18,0.78±0.24,0.81±0.19;矫正1夜;1wk;1mo后裸眼视力逐渐提高(P<0.05),1mo后视力趋于稳定;(2)屈光度的变化：矫正前的屈光度为-6.82±0.71D,联合矫正1a后的屈光度为-6.86±0.77D,差异无统计学意义( P>0.05);联合矫正2a 后的屈光度为-7.11±0.81D,比联合矫正前增加-0.29±0.37D,差异有统计学意义(P<0.05)。(3)眼轴的变化：矫正前的眼轴为26.18±0.57mm,患者联合矫正6mo 为26.19±0.54mm,1a 为26.21±0.47mm,眼轴长度与矫正前的眼轴长度差异无统计学意义(P>0.05);联合矫正2a后眼轴长度为26.37±0.59mm,比矫正前增长0.19±0.28mm (P<0.05);(4)轻度角膜点染发生率较高：经停戴、清洁镜片及使用保护角膜眼药水均能改善。未发现严重眼部并发症。结论：青少年高度近视眼行角膜塑形联合框架眼镜矫正后1a,近视未进展;联合矫正2a,近视仅有轻度进展。未发现严重眼部并发症。该方法相对安全,长期疗效仍需进一步观察。     

Parental awareness of the implications of myopia and strategies to control its progression: A survey-based study

Purpose

Myopia has emerged as a significant public health concern. Effective methods have now been developed to delay its onset and progression. However, this information may not be reaching parents, and they are key players in terms of implementing the necessary preventive measures. This study investigated parental awareness of myopia, its implications and the strategies available for controlling it.

Methods

A self-administered online survey was distributed to parents of children 6–16 years of age. To be eligible to respond, their child had to be myopic or at risk of developing myopia due to family history.

Results

A total of 330 parents completed the survey, of which 321 were included for analysis. Sixty-seven percent of respondents had at least one myopic son/daughter, and most were between −1.00 and −1.75 D. Among parents of myopic children, 20.9% thought that their child's myopia progressed moderately. Sixty-seven percent of parents had a significant level of concern about the progression of the myopia and felt that it was caused mainly by the use of electronic devices and genetics. A generalised linear model showed that parental concern was significantly predicted by the perception of evolution (p < 0.001) and the number of known health-related consequences (p < 0.001). Almost 40% of parents were unaware of the existence of myopia control strategies. Relatives and eye care practitioners are the main sources of information. The most well-known myopia control strategy was myopia control soft contact lenses (29.2%), although the option that most parents would opt for was spectacles with peripheral defocus lenses (47.1%). The selection of a contact-lens-based myopia control method correlated significantly with the age of the children (p < 0.001).

Conclusions

Society in general and parents in particular need more information about myopia, its consequences and the options available for its control. Eye care practitioners play an important role in this issue.     

Improving myopia awareness via school-based myopia prevention health education among Chinese students

AIM: To investigate the myopia awareness level, knowledge, attitude, and skills at baseline and to implement and evaluate the efficacy of myopia prevention health education among Chinese students. METHODS: A total of 1000 middle school students from 2 middle schools were invited to participate in the study, and myopia prevention health education was conducted. The students were assessed at baseline, followed by a survey. The efficacy of health education was evaluated using the self-comparison method pre- and post-health education. RESULTS: The study included 957 and 850 pre- and post-health education participants, respectively. The baseline knowledge of all respondents on myopic symptoms (87.5%), myopia is a risk of eyes (72.9%), myopia prevention (91.3%), myopia increases with age (86.7%), performing periodic eye examinations (92.8%), and one first, one foot, and one inch (84.8%) significantly increased after health education (P<0.001 for all). However, the percentage of students who still did not think it necessary to take breaks after 30-40min of continuous near work was 27.0%. The opinion that “myopia can be cured” was still present in 38.3%. CONCLUSION: Implementing school-based myopia prevention health education improves knowledge, attitudes, and skills regarding myopia among Chinese middle school students.     

Comparison of form-deprived myopia and lens-induced myopia in guinea pigs

AIM: To study the efficacy difference between form-deprived myopia (FDM) and lens-induced myopia (LIM), the degree of myopia, axial length and pathological changes of the posterior sclera from guinea pigs were evaluated.METHODS: Four-week pigmented guinea pigs were randomly assigned into 3 groups, including normal control (n=6), FDM group with monocular cover (n=11) and LIM group with monocular -7D lens treatment (n=11). FDM group was form-deprived while LIM group was lens-induced for 14 d. Refractive error and axial length were measured prior to and post treatment, respectively. Morphological changes of sclera were examined using both light and electronic microscopes.RESULTS: After 14d treatment, refractive errors for FDM group and LIM group were -3.05±0.71D and -2.12±1.29D, respectively, which were significantly more myopic than that of normal controls and fellow control eyes (P<0.01). As for axial length, it was 7.93±0.03 mm for FDM group and 7.89±0.06 mm for LIM group, which were significantly longer than both normal and fellow controls (P<0.01). With respect to both refractory error and axial length, the differences between FDM group and LIM group were not significant (P>0.05). Under light microscope, both FDM group and LIM group showed thinned sclera, disarrangement of fibrosis and enlarged disassociation between fibers. Consistently, ultrastructural examination showed degenerated fibroblasts and thinned fibers in posterior sclera.CONCLUSION:Following two weeks of myopia induction in guinea pigs, with regard to the degree of myopia, axial length and pathological alterations, there was no significant difference between FDM and LIM models. Therefore, FDM and LIM are equally effective and useful as a model of experimental myopia and guinea pigs are ideal animals for induction of experimental myopia because their high sensitivity to both form-deprivation and lens-induction.     

Contralateral effect in progression and recovery of lens-induced myopia in mice

Purpose

Apart from genetic factors, recent animal studies on myopia have focused on localised mechanisms. In this study, we aimed to examine the contralateral effects of monocular experimental myopia and recovery, which cannot be explained by a mere local mechanism.

Methods

One eye of 3-week-old C57BL/6 male mice was fitted with a −30 dioptre (D) lens. The mice were distributed into two groups based on different conditions in the contralateral eye: either no lens (NLC) (n = 10) or a Plano lens on the contralateral eye (PLC) group (n = 6). Mice receiving no treatment on either eye were set as a control group (n = 6). Lenses were removed after 3 weeks of myopia induction. All mice were allowed to recover for 1 week in the same environment. Refractive status, axial length (AL) and choroidal thickness were measured before myopia induction, after 1 and 3 weeks of lens wear and after 1 week of recovery.

Results

One week after removing the lenses, complete recovery was observed in the eyes that wore the −30 D lenses. In both the PLC and NLC groups, the refractive status showed a myopic shift after lens removal. Additionally, the choroid was significantly thinned in these eyes. The −30 D wearing eye showed a significant increase in AL after 3 weeks of lens wear. While the AL of the −30 D wearing eye ceased to grow after the lens was removed, the AL in the PLC and NLC contralateral eyes increased, and the binocular ALs gradually converged.

Conclusions

Recovery of lens-induced myopia was observed in mouse models. In the fellow eyes, the effects, including thinning of the choroid and changes in refractive status, were triggered by contralateral visual cues.     

中西疾坪论治疗近视进展

全球近视发病率呈上升趋势，东亚更是最高发地区，中国、日本和新加坡近年患近视人数骤升；中国患者人数已突破六千万，居世界之首。近视的成因复杂，已知其与环境及遗传因素有关，长期近距离视物是促成近视的主要原因；中医学则责之于心肝肾不足。本文综述近视的分类、成因、中西医治疗方法、前沿性治疗、饮食疗法以及近视的预防。