Toric人工晶状体在合并高度角膜散光白内障中的应用

目的：评估Bi-Flex toric人工晶状体在合并散光的白内障中的应用。

方法：回顾性研究包括16例22眼合并2.50D以上散光的白内障患者。测量了术前与术后的裸眼视力、最佳矫正视力、客观及主观验光、角膜散光仪和角膜地形图测量的散光值。术后人工晶状体屈光轴位置使用向量进行分析。

结果：术后,主观验光散光值从4.05D±1.53D显著降低至1.35D±0.86D,(P<0.05)。屈光轴位置指标J₀,从术前的-0.81±2.02D降至 -0.12±0.62D(P<0.05)。裸眼视力和最佳矫正视力术后1mo时均显著改善(P<0.05),分别为0.24±0.19和0.06±0.08。人工晶状体屈光轴旋转程度平均为2.95±5.25度,86.36%的患眼旋转程度小于10度。术前、术后角膜散光计测量值未见显著差异(J₀ 和J₄₅均有P>0.05)。

结论：对于合并大于2.50D散光的白内障患者,Bi-Flex toric人工晶状体植入是安全有效的治疗方法。     

Comparison of Ziemer FEMTO LDV “Classic” and “Crystal Line” femtosecond laser flap quality by Fourier-domain optical coherence tomography

AIM: To compare the regularity and accuracy of laser in situ keratomileusis (LASIK) flaps created by the Ziemer FEMTO LDV “Classic” (Ziemer “Classic”) and Ziemer FEMTO LDV Crystal Line femtosecond laser (Ziemer Crystal Line).METHODS:Fourier-domain optical coherence tomography (RTVue OCT) was used tomeasure the morphology of 200 LASIK flaps of 100 consecutive patients created with the Ziemer Classic (100 flaps) or the Ziemer Crystal Line (100 flaps) at one week postoperatively. Flap thickness was evaluated at 36 specified measurement points on each flap. For all procedures with both lasers, the nominal flap thickness was 110µm.RESULTS:The mean flap thickness of the Ziemer Crystal Line group(102.49±2.68µm) was thinner than that of the Ziemer Classic group (107.65±5.09µm) (P<0.01). Average thickness of all flaps was uniform within 4µm at all measurement points. The flaps in the Ziemer Crystal Line group were more regular than those in the Ziemer Classic group when measured from the center to the periphery. The maximum deviation from the nominal 110µm of 36 measurements was 8µm in the Ziemer Classic group, while in the Ziemer Crystal Line group it was 9µm. Within the 3 600 measurements on the 100 eyes, differences greater than 20µm were observed 0.14% in the Ziemer Classic group, and 0.04% in the Ziemer Crystal Line group.CONCLUSION:The flaps created with the Ziemer FEMTO LDV Crystal Linefemtosecond laser are more uniform and thinner than those created by the Ziemer FEMTO LDV Classic femtosecond laser.     

Non-cycloplegic spherical equivalent refraction in adults:comparison of the double-pass system, retinoscopy, subjective refraction and a table-mounted autorefractor

AIM:To assess the effect of myopia on the thickness of retinal nerve fiber layer (RNFL) measured by 3D optical coherence tomography (3D-OCT) in a group of nonglaucomatous Chinese subjects.METHODS:Two hundred and fifty-eight eyes of 258 healthy Chinese myopic individuals were recruited and four groups were classified according to their spherical equivalent (SE):low myopia (n=42, -0.5D<SE<-3.0D), moderate myopia (n=120, -3.0D≤SE<-6.0D), high myopia (n=58, -6.0D≤SE<-8.0D) and extreme high myopia (n=38, SE≥-8.0D). The RNFL thickness profile including superior, nasal, inferior and temporal quadrant and each of the 12 clock-hour thicknesses were measured by 3D-OCT. The RNFL thicknesses among four sample groups were performed by one-way analysis of variance (one-way ANOVA) and least significant difference test (LSD test). Correlations between RNFL thickness and axial length/spherical equivalent were performed by linear regression analysis.RESULTS: The overall RNFL parameters shown significant differences between groups excluding 7, 9, 10, 11 o’clock hour thickness. The RNFL thickness of superior, nasal, inferior, average and 1, 2, 3, 4, 5, 6, 12 o’clock sectors were decreased with the increasing axial length and higher degree of myopia. In contrast, as axial length and the degree of myopia increased, the temporal and 8, 9 o’clock sectors thicknesses were increased. A considerable proportion of myopic eyes were classified as outside the normal limits. Six o’clock was the most notable of the total, which 43.4% were outside the normal limits.CONCLUSION:On the measurement of RNFL, the characteristics of RNFL with the change of the degree of myopia were observed. As the degree of myopia increases, the RNFL thickness measured by 3D-OCT including the average and superior, nasal, inferior sectors decreases. And due to the change of RNFL thickness, it should be considered when using OCT to access for the damage of glaucoma especially people with myopia.     

Clinical evaluation of the L80 autorefractometer

Background: A clinical evaluation of the L80 wave+ autorefractometer (Visionix Luneau, Chartres, France) was performed to evaluate its validity and repeatability compared with non‐cycloplegic subjective refraction. The L80 wave+ autorefractometer is a new instrument based on the Hartmann‐Shack principle that has a specific autorefraction function using the wavefront device and can also measure keratometry, topography of the cornea and higher‐order aberrations. Methods: Refractive error measurements were obtained from 100 eyes of 50 subjects (age, 25 ± 2.71 years) subjectively by one masked practitioner and objectively with the L80 wave+ autorefractometer (with a 3.0 mm pupil) by a second practitioner. Intra‐test and inter‐test (within a week after the initial objective measures) variability was assessed on 28 new subjects (56 eyes). Results: The results of the objective and subjective measurements of refractive error were very similar (mean difference 0.03 ± 0.47 D, p = 0.49 for sphere; 0.05 ± 0.27 D, p = 0.06 for cylinder; 0.06 ± 0.44 D, p = 0.20 for spherical equivalent; 0.01 ± 0.13 D, p = 0.37 for J₀ and ‐0.005 ± 0.12 D, p = 0.69 for J₄₅). High intra‐test and inter‐test repeatability were demonstrated for all parameters measured and found comparable with other clinical autorefractors. Conclusion: The L80 wave+ autorefractometer represents a reliable and valid objective refractive tool for general optometric practice.     

Cycloplegic refraction in preschool children: comparisons between the hand-held autorefractor, table-mounted autorefractor and retinoscopy

Aims: It is common for refraction to be measured using different testing methods in children, with much debate still ongoing on the preferred method. Therefore, we compared cycloplegic refraction measurements using three objective methods in a large cohort of children. Methods: We present the findings from a total of 51 children who were recruited and examined as part of the Strabismus, Amblyopia and Refractive error in Singapore preschool children (STARS) study. Each child underwent a comprehensive eye examination, which included cycloplegic refraction using a hand‐held autorefractor (Retinomax), a table mounted autorefractor (Canon FK‐1) and streak retinoscopy. Spherical equivalent (SE) was calculated as (sphere + half of minus cylinder) and astigmatism was determined using the negative cylindrical component. Results: The current study sample consisted of 29 boys and 22 girls aged between 24 and 72 months (mean age 52.3 months). The mean spherical equivalent (SE) using the table‐mounted autorefractor (1.03 ± 1.64 D) was not significantly different from the streak retinoscopy (1.09 ± 1.58 D, p = 0.66). However, the mean SE using the hand‐held Retinomax (0.80 ± 1.43 D) was significantly different (more ‘minus’p = 0.0004) to streak retinoscopy. The astigmatism measured using the hand held (?0.89 ± 0.51 D) and table‐mounted autorefractor (?0.83 ± 0.61 D) were significantly greater than that obtained with streak retinoscopy (?0.58 ± 0.56, p = 0.0003). Conclusions: The table‐mounted autorefractor provided a reading more similar to that of streak retinoscopy than to that of the hand‐held autorefractor. However, there were only small differences in mean SE (<0.32 D) between the hand‐held Retinomax and the other methods, which will have implications in research investigations of refractive error.     

学龄前儿童电脑验光和检影验光的对比研究

目的:比较电脑验光和检影验光在学龄前儿童客观屈光检查中的应用价值。方法:门诊屈光不正的学龄前儿童98例196眼,年龄3～6岁,使用10g/L阿托品眼膏涂眼,2次/d,连用4d,第5d停药后分别使用电脑验光和检影验光,结果进行统计学分析比较。结果:比较电脑验光和检影验光的结果显示远视球镜均值电脑验光法(2.70±2.75D)所测结果低于检影验光法(2.99±2.09D),行配对t检验,两种方法结果比较差异有统计学意义(P<0.05);近视球镜均值电脑验光法(-2.74±1.25D)所测结果高于检影验光法(-2.35±2.18D),结果比较差异有统计学意义(P<0.05);散光轴向两种方法比较差异无统计学意义(P>0.05),而散光度数值均值比较差异有统计学意义(P<0.05)。结论:电脑验光和检影验光法在学龄前儿童散瞳验光应用中各有利弊,临床工作中需结合使用。     

多种验光模式在LASIK术前检查中的应用

目的 比较准分子激光原位角膜磨镶术(LASIK)前多种验光模式的差异性和相关性.方法 前瞻性临床研究.拟接受LASIK手术122例(241眼),近视球镜度为-0.75～-13.25 D,平均(-5.57±2.40)D;柱镜度为-0.25～-5.50 D,平均(-0.96±0.66)D.术前分别进行检影验光、电脑验光、主觉验光以及OrbscanⅡ检查;术后1年进行主觉验光,对获得数据进行分析.检影验光、电脑验光与主觉验光结果的差异性采用单因素方差分析,Orbscan Ⅱ结果与主觉验光结果的差异性采用配对t检验.不同验光结果的相关性采用Pearson相关分析.结果 通过检影验光、电脑验光和主觉验光获得的球镜度分别为(-5.20±2.61)D、(-5.64±2.71)D和(-5.57±2.40)D,差异具有统计学意义(F=38.586,P＜0.01);检影验光、电脑验光和主觉验光获得的柱镜度分别为(-0.99±0.66)D、(-1.03±0.73)D和(-0.96±0.66)D,差异具有统计学意义(F=15.147,P＜0.01),OrbscanⅡ获得的柱镜度为(-1.16±1.84)D,与主觉验光的差异具有统计学意义(t=3.190,P＜0.01);检影验光、电脑验光和OrbscanⅡ提示的散光轴向与主觉验光结果差异均无统计学意义.不同验光模式所得的验光结果均具有密切的线性相关(r均＞0.9,P＜0.01).结论 应采取多种验光手段对预进行LASIK手术患者的屈光状态进行综合评估,以确保手术效果.     

Retinoscopy/autorefraction: which is the best starting point for a noncycloplegic refraction?

PURPOSE: The aim of this study was to estimate the agreement between an autorefractor (Nidek ARK 700A, Gamagori, Japan) and retinoscopy with subjective refraction. METHODS: Measurements of autorefraction obtained with the ARK700A and retinoscopy were performed on 192 right eyes from 192 healthy young adults and compared with subjective refraction. These measurements were performed without cycloplegia. The age range was 18 to 34 years, with a mean value of 21.6 years and an SD of 2.66 years. RESULTS: A comparison of the autorefractor and subjective refraction results shows that (1) for the mean spherical equivalent (M), the autorefractor yields more negative values (-0.44 +/- 0.54 D; p = 0.000); (2) for the Jackson cross-cylinder at axis 0 degrees (J0), the autorefractor yields more positive values than the subjective ones (0.05 +/- 0.13 D; p = 0.000); and (3) for the Jackson cross-cylinder at axis 45 degrees (J45), the autorefractor results are more negative (-0.02 +/- 0.09 D; p = 0.019). The differences found for each component M, J0, and J45 are statistically significant. By comparing retinoscopy with the subjective examination, there are no statistically significant differences found for the M component (-0.02 +/- 0.33 D; p = 0.304). For the J0 and J45 components, the differences are statistically significant (0.07 +/- 0.10 D, p = 0.000; -0.01 +/- 0.08 D, p = 0.008). CONCLUSIONS: The present results confirm that when performed by an experienced clinician, retinoscopy is more accurate than automatic refraction, giving a better starting point to noncycloplegic refraction.     

The Auckland Cataract Study: demographic, corneal topographic and ocular biometric parameters

Purpose : To determine patient demographics and the ocular biometric parameters in patients presenting for cataract surgery within the public hospital system, in a defined New Zealand population. Method : Prospective study of 502 eyes of 488 consecutive patients undergoing cataract surgery. A clinical assessment, including refraction, keratometry (K), A‐scan ultrasound and Orbscan II computerized topography was performed on each eye. Results : The mean age of the group was 74.9 ± 9.8 years (mean ± SD) with a female predominance (62%). Ethnic origin included 72% European, 8% Maori, 10% Pacific Islander, 4% Asian, 3% Indian and 3% other ethnic origins. The mean Log MAR visual acuity of eyes prior to cataract surgery was 0.88 ± 0.57 (approximately 6/48^–1). Corneal topographic (keratometric) maps were classified into five groups: 34% round, 10% oval, 31% symmetrical bow tie, 12% asymmetrical bow tie and 13% irregular. The mean steepest K measurement was 44.1 ± 1.7 D, the median keratometric astigmatism 0.89 D (range 0.0–6.5 D) and the steepest corneal meridian was horizontal in 50% and vertical in 43%. Seven per cent of corneas were spherical. Refraction revealed a mean sphere of 0.0 ± 3.1 D and a mean cylinder of –1.2 (range 0.0–7.5 D). Refractive astigmatism was with‐the‐rule in 15%, against‐the‐rule in 50% and oblique in 15%, with 20% spherical. Axial length was a mean of 23.14 ± 1.03 mm. Conclusion : Patients presenting for cataract surgery in this study were predominantly elderly, female, of European Caucasian ethnicity and exhibited relatively poor corrected visual acuity in the affected eye. Interestingly, 41% of eyes demonstrated bow‐tie topographic patterns, largely exhibiting with‐the‐rule astigmatism. However, assessment by keratometry or refraction highlighted against‐the‐rule more frequently; this may have implications for combined cataract and astigmatic surgery. The mean axial length was slightly shorter than expected for a group of predominantly European ethnic origin, although the mean refractive error was emmetropic.     

手持电脑验光仪在招飞体检中的应用

目的：比较手持电脑验光仪与带状光检影仪在招飞屈光检查中屈光值测量的差异,探讨手持电脑验光仪在招飞体检中应用的可行性。
　　方法：对进入屈光检查的招飞学生317名634眼散瞳后,分别用手持电脑验光仪和带状光检影仪进行验光检查。对主要指标(球镜度数、柱镜度数及轴向)的屈光值进行差异性检验和相关性分析,并对淘汰率进行比较分析。
　　结果：手持电脑验光仪球镜和柱镜屈光度值较视网膜检影结果偏负,其差异有统计学意义(P<0.05),但具有统计学相关性(r=0.733,0.694),两者轴位的检验结果差异无统计学意义(P>0.05)。手持验光仪淘汰率较检影高,存在有误淘现象。
　　结论：手持电脑验光仪与检影测量结果有较好的一致性,在招飞屈光检查中有应用的价值。     

��bereinstimmung subjektiver und objektiver Refraktionsmessungen nach INTRACOR-Femtosekundenlaser-Behandlung

Background

The goal of this study was to determine the accuracy of autorefraction measurements in patients after INTRACOR intrastromal femtosecond laser treatment of presbyopia by comparing the agreement between the subjective and objective refraction.

Patients and methods

In this study the data of 19 patients with a mean age of 56.5±6.0 years following INTRACOR treatment were analyzed pre-operatively and 12 months postoperatively. Measurements of the subjective refraction and the results of the autorefractor Nidek-660A in miosis were compared. INTRACOR is a refractive intrastromal femtosecond laser treatment to correct presbyopia. During the procedure a series of five concentric rings in the central stroma are cut which cause a change in the curvature of the cornea.

Results

The differences in sphere and spherical equivalent between subjective refraction and autorefraction were not significant (t-test p>0.05 and Wilcoxon test p>0.05). Comparing the cylinder of the two measurements a significant difference (t-test p<0.05) was found. Focusing on the difference of the postoperative measurements of the subjective refraction and autorefraction a correlation (within ±0.5?D) of 89% in the sphere, 100% in cylinder and 68% in the spherical equivalent was detected. With one exception the differences in sphere, cylinder and the spherical equivalent were within ±1.25?D. In several patients the performance of the autorefraction with the Nidek-660A was somewhat complicated and the measures had to be repeated frequently.

Conclusion

The agreement between subjective refraction and objective measurements of the Nidek-660A of patients following INTRACOR-treatment was good. However there was a significant difference in the cylinder values. Therefore thorough comparison of measurements obtained with the autorefractor and the subjective refraction is recommended.     

Objective autorefraction in posterior chamber pseudophakia.

Automated refraction with the Canon RK-1 Autoref keratometer was evaluated in 110 eyes (110 patients) six to eight weeks after they had undergone extracapsular cataract extraction with posterior chamber intraocular lens implantation and achieved a best corrected visual acuity of at least 6/12. Autorefraction readings were obtained in 100 (91%) of these eyes. The agreement between autorefraction and clinical refraction data was 98% for spherical equivalence less than 0.51 dioptres (D), 95% for sphere power less than 0.51D, 94% for cylinder power less than 0.51D, and 85% for cylinder axis less than 11 degrees. Autorefraction can provide acceptably accurate postoperative refraction values in pseudophakic eyes.     

Use of the HARK autorefractor in children

PURPOSE: We investigated the reliability, accuracy, and repeatability of an autorefractor with the capability of over-refracting and measuring visual acuity for use in children in a prospective study. METHODS: Before and after cycloplegia, 68 children (mean +/- SD age, 10 +/- 3 years, range 5-16 years) underwent autorefraction twice with the HARK 599 Autorefractor (Humphrey Instruments Inc., San Leandro, CA), subjective over-refraction through the HARK autorefractor, and subjective refraction using a phoro-optometer. After cycloplegia, retinoscopy was performed. Results are reported for one eye (left) of each child. RESULTS: For 68 eyes of 68 children, before and after cycloplegia, correlation coefficients (R) for autorefraction reproducibility exceeded 0.95 for all comparisons of sphere and cylinder. R for spherical values for autorefraction vs. over-refraction was 0.93 and vs. subjective refraction 0.83 before cycloplegia and 0.94 and 0.97 after cycloplegia. Comparing values before and after cycloplegia, autorefraction, over-refraction, and subjective refraction, the data correlated > 0.81 for sphere and 0.75 to 0.87 for cylinder. Cycloplegic retinoscopy compared with autorefraction, over-refraction, and subjective refraction had R > 0.86 for sphere and cylinder for all comparisons except one. Cycloplegia increased the proportion of spherical equivalent values within 0.625 D of the subjective refraction from 41 of 68 eyes (61%) for auto- and over-refraction to 64 (94%) and 51 (75%) of the 68 eyes, respectively. A visual acuity of 20/30 or better was produced in 50 of 68 (73%) eyes with automated refraction before and after cycloplegia and in 62 (92%) with subjective refraction before cycloplegia and subjective refraction and retinoscopy after cycloplegia. Subjective over-refraction did not significantly improve the visual acuity. CONCLUSIONS:In children, HARK autorefraction improved in accuracy, when compared to subjective refraction, and the level of visual acuity improved after cycloplegia. Over-refraction through the instrument did not improve the results before or after cycloplegia.     

Self‐assessment of refractive errors using a simple optical approach

Background

This explorative study investigated procedures for the self‐assessment of spherocylindrical refractive errors.

Methods

Eighteen participants with a mean age of 34.0 ± 8.8 years were enrolled. Adjustable Alvarez lenses were mounted in a rotatable ring holder and two procedures were tested for the self‐adjustment: (1) rotation of the lens in three meridians: 0°, 60° and 120° and (2) rotation of the optotypes in the same meridians. Starting from maximum positive power, the participants were required to decrease the power of the Alvarez lens until the optotypes (0.0 logMAR) appeared to be clear the first time. Best‐corrected visual acuity (BVA) was measured using a psychophysical staircase procedure. Bland–Altmann analysis was carried out in order to calculate the limits of agreement between the self‐refraction method and the standard subjective refraction.

Results

Using procedure 1, 77 per cent of the subjects achieved a VA ≥ 0.1 logMAR (6/7.5) and the same was true for 88 per cent of the subjects using procedure 2. Using procedure 1, a significantly worse BVA was found, when compared to subjective refraction (ΔVA = ?0.15 logMAR, F_3,140 = 7.11, p = 0.046, median test). Analysis of variance (ANOVA) analysis showed a significant influence of the refraction method on the oblique astigmatism component J₄₅ but not for the spherical equivalent M and the straight astigmatism component J₀ (M: F_3,140 = 0.532, p = 0.661; J₀: F_3,140 = 0.056, p = 0.983; J₄₅: F_3,140 = 13.97, p < 0.001; ANOVA). The limits of agreement for the spherical equivalent error M were ± 1.10 D and ± 1.20 D and for the astigmatic components J₀ ± 0.78 D and ± 0.59 D and for J₄₅ ± 0.62 D and ± 0.54 D, for procedure 1 and procedure 2, respectively.

Conclusions

Fixed adjustable Alvarez lenses and rotatable stimuli can provide a fast and precise self‐assessment method to measure the spherocylindrical error of the eye.

     

Cataract and its surgery in Fiji

Background: To characterize cataract and its surgery among adults aged ≥40 years in Fiji. Design: Population‐based cross‐sectional survey using multistage cluster random sampling. Participants: 1381 (= 73.0% participation); eight provinces on Viti Levu. Methods: Interview‐based questionnaire; visual acuity measured; autorefraction; dilated ocular examination. Main Outcome Measures: Prevalence; predictors; surgical outcomes. Results: Being Indian (P = 0.001), elderly (P < 0.001), and previous/current smoker (P = 0.036) were predictive of at least one unoperated vision‐impairing or operated cataract. Gender (P = 0.062) and diabetes (P = 0.384) were not. Unoperated cataract (predominantly nucleosclerosis) was the second most frequent (25.0%) cause of low vision (<6/18, ≥6/60) and commonest (71.1%) of blindness (<6/60). Ethnicity‐gender‐age‐domicile adjusted and extrapolating to the Fiji population aged ≥40 years, prevalence of cataract‐induced low vision and blindness were each 1.7% (95% confidence interval [CI] 1.0–2.4%). At least one eye of 4.6% and both of 1.8% participants had surgery (86.4% extracapsular). Gender (P = 0.213), age (P = 0.472) and rural/urban domicile (P = 0.895) were not predictors of surgery among those who required it in at least one eye. After intraocular lens surgery: 50.7% had pupillary posterior capsular opacification; mean spherical equivalent was ?1.37 ± 1.95D (range, ?6.38 to +2.25D); mean cylindrical error was 2.31 ± 1.75D (range, 0.0 to 8.75D); ≥N8 for 39.5%; ≥6/18 for 56.6%; <6/60 for 19.7%, with 2.6% no light perception. Ethnicity‐gender‐age‐domicile adjusted and extrapolating to the Fiji population aged ≥40 years, Cataract Surgical Coverage (Person) was 47.5% (95%CI 29.2–65.8%) at <6/18, and 65.2% (95%CI 37.8–92.6%) at <6/60. Conclusions: Fiji cataract services and outcomes compare favourably with those of neighbouring Papua New Guinea and Timor Leste.     

AcrySof IQ Toric人工晶状体植入矫正角膜散光的疗效

目的：评价白内障手术中植入AcrySof IQ Toric散光型人工晶状体矫正角膜散光的效果及人工晶状体在囊袋内的稳定性。

方法：对21例26眼伴有角膜规则散光的白内障患者,植入AcrySof IQ Toric散光型人工晶状体,观察术前及术后裸眼视力、最佳矫正视力; 术前角膜散光、预计散光、总散光,术后角膜散光及残余散光; 以及术后人工晶状体旋转度。

结果：术后所有患者裸眼视力及最佳矫正视力均明显提高; 术后残留散光0.55±0.33D,与术前总散光2.05±0.57D相比明显下降(t=13.574,P<0.05); 与术前预留散光0.47±0.19D比较无统计学意义(t=1.149,P>0.05)。术后3mo角膜散光-1.89±0.53D,与术前角膜散光2.01±0.58D相比无差异(t=1.908,P>0.05); 所有26眼的人工晶状体旋转度均<20°,平均旋转为(3.65±2.86)度。

结论：白内障超声乳化吸除联合AcrySof IQ Toric IOL植入矫正散光手术,能够有效的减少患者的散光,术后IOL旋转稳定性良好,是治疗白内障合并散光患者的有效的手术方法。     

近视儿童配戴单光镜后的周边屈光研究

目的:研究近视儿童配戴单光镜后对周边视网膜屈光状态的影响。方法:采用自身对照研究。入选10～15岁近视儿童48例,睫状肌麻痹下使用Grand Seiko WAM5500型红外验光仪测量右眼视网膜中心凹0°以及鼻颞侧10°,20°,30°的屈光值,分别在裸眼和配戴单光眼镜时测量。结果:近视儿童的平均屈光度为-3.99±1.22D,相对周边屈光度在水平视野上为远视性离焦。随着注视角度的增大,相对远视性离焦量增大。戴镜后的相对周边远视性离焦量较裸眼时增大(P<0.01)。戴镜前后的J180及J45相比较无统计学差异。结论:近视儿童配戴单光镜后周边视网膜远视性离焦量增大。根据周边视网膜的聚焦状态改进镜片的设计可能会成为近视矫正的新思路。     

Safety,efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000‐Hz scanning spot excimer laser

Purpose: To evaluate the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000‐Hz scanning spot excimer laser (Concept System 1000; WaveLight GmbH, Erlangen, Germany). Methods: LASIK was performed on twenty eyes with myopia or myopic astigmatism (mean spherical equivalent refraction: ?3.97 ± 1.72 dioptres (D); mean cylinder: ?0.84 ± 0.77 D) using a microkeratome for flap creation and the Concept System 1000 for photoablation. Patients were examined preoperatively as well as 1, 3 and 6 months after the treatment. Manifest sphere and cylinder, uncorrected (UCDVA) and best corrected (BCDVA) distance visual acuity, corneal topography and pachymetry were analysed. Results: We observed no adverse events that might have been associated with the use of a repetition rate of 1000 Hz. All eyes maintained or had improved BCDVA at 6 months after treatment when compared to preoperative values. Six months after LASIK, UCDVA was 20/20 or better in 85% and 20/25 or better in 100% of the eyes. The spherical equivalent refraction was within ±0.50 D in 95% of the eyes at 6 months after surgery. The refraction stayed stable over time; 95% of the eyes changed <0.5 D postoperatively. Conclusion: LASIK with the prototype 1000‐Hz excimer laser was safe, efficient and predictable. The postoperative refraction was stable over time. There were no specific clinical side‐effects that might be associated with the use of such a high repetition rate.