调制传递函数对全飞秒激光近视屈光手术后早期视觉质量的评价

背景 全飞秒激光辅助的屈光手术已广泛用于临床,其术后术眼视觉质量的改善情况是临床医师关注的主要问题.调制传递函数（MTF）是评价视觉质量的主要指标. 目的 研究近视患者行全飞秒激光屈光手术后在明暗条件下（3 mm或6 mm瞳孔直径）MTF的变化,以评价术后的早期视觉质量. 方法 采用回顾性系列病例观察的研究方法,选取2012年7-10月在南京军区南京总医院行全飞秒激光屈光手术的中低度近视[等效球镜度（SE）为-2.25 ～-5.75 D]患者23例40眼作为研究对象,分析并比较术眼术前及术后1d、1周、1个月的视力变化;用i-Trace视功能分析仪测量术眼3 mm和6 mm瞳孔直径下术前及术后1d、1周、1个月总像差、低阶像差和高阶像差的MTF值,比较3 mm和6 mm瞳孔直径间不同像差MTF的差异.分别对瞳孔直径3 mm或6 mm时在最佳矫正视力（BCVA）状态下测量的术前及术后1d、1周、1个月间在5、10、15、20、25 c/d空间频率下的MTF值进行比较. 结果 与术前裸眼视力和BCVA比较,术眼术后1d、1周、1个月的视力逐渐提高,各时间点间视力的比较差异有统计学意义（F=10.341,P=0.000）;术眼术后屈光度平均矫正量为3.795 D.术后1d、1周、1个月,3 mm瞳孔直径下总像差、高阶像差和低阶像差下MTF值随时间的延长均有升高的趋势,但差异均无统计学意义（P＞0.05）.6 mm艟孔直径下术后各时间点总像差、低阶像差下MTF值明显高于术前,差异均有统计学意义（P＜0.05）,而术前及术后各时间点高阶像差MTF值的变化差异无统计学意义（F=0.260,P=0.854）.与3 mm瞳孔直径下比较,术眼术前及术后1个月6 mm瞳孔直径下低阶像差和高阶像差的MTF值明显下降,差异均有统计学意义（术前：P=0.050、0.001;术后：P=0.012、0.001）.3 mm瞳孔直径下各空间频率的MTF值差异均无统计学意义（均P＞0.05）,而6 mm瞳孔直径下各时间点10、15、20、25 c/d空间频率下MTF值随着术后时间的延长均逐渐升高,差异均有统计学意义（P=0.044、0.043、0.024、0.014）. 结论 全飞秒激光近视屈光手术能够消除低阶像差,术后MTF值明显提高,患者裸眼视力提高,从而改善患者的视觉质量.应用MTF值能够客观地分析全飞秒激光近视屈光手术后视觉质量的变化.     

暗室瞳孔直径下Nd:YAG激光后囊膜切开术后屈光状态及视觉质量的变化

目的　探讨暗室瞳孔直径下Nd:YAG激光后囊膜切开术后的屈光状态、高阶像差（higher order aberration，HOA）、视觉相关生活质量变化特点。方法　收集2017年9月至11月在我院就诊的后发性白内障患者57例73眼。所有患者均行Nd:YAG 激光后囊膜切开术治疗，切开直径为暗室下瞳孔直径（3~4 mm），观察激光术前后最佳矫正视力（best corrected visual acuity，BCVA）、屈光状态及Catquest-9SF量表总分和各问题得分的变化，应用KR-1W视觉质量分析仪分别测量分析4 mm和6 mm瞳孔直径下激光术前后HOA的变化。结果　Nd:YAG激光后囊膜切开术后BCVA（0.095±0.020）较术前（0.550±0.039）显著提高，差异有统计学意义（P<0.05）；术前球镜度数、等效球镜度数分别为（-0.938±0.209）D、（-1.581±0.207）D，术后分别为（-0.658±0.218）D、（-1.204±0.213）D，手术前后差异均有统计学意义（均为P<0.05）；术后Catquest-9SF量表总分及各问题得分均较术前显著提高，差异均有统计学意义（均为P<0.05）；4 mm、6 mm瞳孔直径下的全眼及眼内总HOA、三阶像差、四阶像差、三叶草像差、彗差、二阶像差术后较术前显著降低，差异均有统计学意义（均为P<0.05）。结论　暗室瞳孔直径下Nd:YAG激光后囊膜切开术后，屈光状态呈远视漂移，高阶像差明显降低，视力及视觉相关生活质量问卷评分显著提高，患者视觉质量明显改善。     

非球面和球面人工晶状体植入术后高阶像差的比较

目的对比同一个体两眼分别植入非球面和球面人工晶状体(IOL)后高阶像差的差异。设计前瞻性、病例对照研究。研究对象33例(66眼)双眼老年性白内障患者。方法患者接受超声乳化白内障吸除术后,两眼分别植入球面(Canon Staar KS-3)和非球面(Canon Staar KS-3Ai)IOL。按照IOL设计的差异分成两组,球面组和非球面组,手术后3个月观察患者的视力、最佳矫正视力、IOL位置、屈光状态、高阶像差、瞳孔大小等指标。比较两组高阶像差的差异。主要指标视力、最佳矫正视力,IOL的居中性、屈光状态、瞳孔直径、3阶像差、4阶像差、4阶球差(Z40)、5阶像差及总高阶像差的均方根(RMS)。结果在瞳孔直径6mm时,非球面IOL组的4阶像差(0.193±0.098)μm、4阶球差(0.037±0.099)μm、总像差RMS(0.498±0.072)μm均低于球面IOL组(0.403±0.155)μm、(0.381±0.142)μm、(0.737±0.164)μm,而在瞳孔直径6mm时的3阶和5阶像差RMS,瞳孔直径5mm时总像差RMS两组间比较差异无统计学意义(P均>0.05)。低对比度条件下,10例(30%)非球面组患者视物较球面组患者清晰。瞳孔6mm时,非球面组和球面组平均近视漂移分别是(-0.29±0.09)D和(-0.87±0.16)D,差异有统计学意义(P=0.033)。结论植入非球面IOL后,虽然可以明显降低4阶球差,但是两组间在术后视力和最佳矫正视力方面并没有统计学差异,高阶像差的差异主要表现夜间近视漂移的减少和瞳孔直径5mm以上时的低对比度视力的提高。     

轴性高度近视眼高阶像差与眼轴长度及屈光度的相关性研究

目的　研究轴性高度近视眼4 mm及6 mm瞳孔直径下眼球高阶像差的特点及其与眼轴长度和眼球屈光度的相关性。方法　选取北京大学国际医院眼科轴性高度近视患者共30例（30眼）,眼轴长度均≥26 mm,等效球镜度数≤-6.00 D。OPD-Scan Ⅲ光学视觉质量分析仪测量4 mm及6 mm瞳孔直径下患者角膜、眼内及全眼高阶像差,应用IOL-Master测量患者眼轴长度。使用SPSS 20.0软件进行统计学分析,采用配对样本t检验比较4 mm与6 mm瞳孔直径下角膜、眼内及全眼高阶像差的差异,Pearson相关性分析用于分析4 mm与6 mm瞳孔直径下各高阶像差与眼轴长度及等效球镜度数的相关性。结果　4 mm瞳孔直径下角膜高阶像差、眼内高阶像差及全眼高阶像差分别为（0.125±0.040）μm、（0.140±0.042）μm和（0.136±0.052）μm,均较6 mm瞳孔直径下的（0.422±0.110）μm、（0.348±0.101）μm、（0.341±0.109）μm显著降低,差异均有统计学意义（均为P＜0.001）;4 mm瞳孔直径下角膜高阶像差与全眼高阶像差相比差异无统计学意义（P=0.193）;6 mm瞳孔直径下角膜高阶像差比全眼高阶像差显著升高（P=0.002）。4 mm瞳孔直径、6 mm瞳孔直径下各高阶像差与等效球镜度数和眼轴长度均无显著相关性（均为P>0.05）。结论　轴性高度近视患者6 mm瞳孔直径比4 mm瞳孔直径下角膜高阶像差、眼内高阶像差及全眼高阶像差均显著增加。4 mm瞳孔直径及6 mm瞳孔直径下各高阶像差与等效球镜度数和眼轴长度均无显著相关性。眼内高阶像差对角膜高阶像差可能有补偿作用,眼内球差在角膜高阶像差的补偿中可能起重要作用。     

0．2％酒石酸溴莫尼定滴眼液对国人瞳孔影响的观察

目的本研究旨在探讨0.2%酒石酸溴莫尼定滴眼液(阿法根)在不同亮度条件下对正常人瞳孔大小的影响。方法24名志愿者的右眼给与0.2%阿法根滴眼液1滴,在给药前及给药后30 m in、4 h和6 h分别以红外线瞳孔测量仪在不同亮度条件下测定瞳孔的大小。结果在亮条件下(150 cd/m2)及暗条件下(0.2 cd/m2),相对于给药前的瞳孔平均直径,给药后30 m in、4 h和6 h后的瞳孔平均直径均明显减小,以上数值分别为:(4.7±0.5)mm、(3.6±0.4)mm、(3.7±0.5)mm和(3.8±0.6)mm(P<0.05);(6.1±0.6)mm、(4.3±0.3)mm、(4.0±0.6)mm和(4.7±0.52)mm(P<0.05)。结论0.2%阿法根对正常人瞳孔有着显著的缩瞳作用,符合α2-肾上腺素能受体激动后反馈抑制肾上腺素释放的药理学作用。     

准分子激光角膜屈光手术对人眼高阶像差的影响

目的评价不同屈光手术方式治疗屈光不正前后的高阶像差的改变。方法近视患者777例（1554眼）,按屈光度分为低、中、高三组,各206、950、398眼。根据患者自愿原则,分别给予不同的屈光手术治疗。其中,准分子激光原位角膜磨镶术（LASIK）1136眼,角膜地形图引导的LASIK术（TOGCA）404眼,波前像差引导的LASIK术（WAGCA）14眼。采用iTrace全功能视觉分析仪测量手术前后角膜及晶状体的高阶像差。采用方差分析和配对t检验对所得数据进行统计学分析。结果近视眼患者术前角膜与晶状体各像差互为补偿。角膜高阶像差：术前不同屈光度组间角膜高阶像差的差异无统计学意义,术后各组角膜高阶像差的增加随着屈光矫正度数的增加而增加,其中增加最大的是球差,TOGCA患者术后球差增加较小。晶状体高阶像差：术前高度近视组较低、中度近视组有更多的总高阶像差和球差,手术前后晶状体高阶像差的差异无统计学意义。结论角膜和晶状体高阶像差互为补偿,人眼高阶像差对视觉质量影响较小。屈光手术导致人眼高阶像差的增加,而个体化切削术能减少高阶像差的产生,提高屈光手术患者的视觉质量。     

单纯性近视屈光不正眼高阶像差的观察

目的 观察年龄18～28岁青年人群眼球高阶像差的分布特点以及近视性屈光不正与高阶像差的关系.方法 对42只正视眼和112只单纯性近视眼使用 Hartmann-Shack原理设计的COAS波前像差仪进行波前像差检查,分别提取不同瞳孔直径时高阶像差的均方根(RMS)值,对比分析不同屈光状态组之间的高阶像差的差异性.结果 正视组和近视各组间在3～6mm 瞳孔直径下球差、慧差、三叶草、总高阶像差以及3rd至6th高阶像差差异有统计学意义.5mm和6mm瞳孔直径下,正视组和近视各组球差、三叶草、总高阶像差以及3rd、4th、6th高阶像差差异有统计学意义.瞳孔直径对高阶像差的影响显著,高阶像差随瞳孔变化的趋势表现出不一致性,随着瞳孔直径增大相应增加,总体以3rd和4th像差变化显著.各屈光度组的全眼高阶像差变异度较大,球差、三叶草分布离散程度分别于5mm和6mm瞳孔直径下差异有统计学意义(F=2.74,P=0.0454;F=3.93,P=0.0102).结论 正常人眼的高阶像差个体差异较大,近视的屈光度对高阶像差有一定的影响.     

近视LASIK手术后高阶像差的改变

目的分析LASIK手术对高阶像差的影响，分析IASIK术的近视屈光度与LASIK术后眼的高阶像差的关系。方法采用WASCA波前像差仪测量150眼LASIK术前及术后1月及3月瞳孔直径分别为小瞳孔（3mm）及人瞳孔（6．25mm）时的总高阶像差的均方根及第三和第四阶像差的Zemike系数，并计算出球差、慧差、第三及第四阶像差的均方根。对结果进行方差分析和直线相关分析。结果LASIK术后，大瞳孔直径和小瞳孔直径下高阶像差均明显增高。无论瞳孔人小．术后3月较1月时高阶像差均轻微下降。人瞳孔直径下，光区直径为6．25mm时，术后球差、第四阶像差和总高阶像差与术前屈光度存在正相关。结论IASIK术后，高阶像差明显增高，尤以球差最明显。术前屈光度越高，手术所导致的高阶像差也越大，屈光度过高的近视眼不宜采用波前像差引导的个体化屈光手术。     

眼高阶像差评价分析

目的 :评价眼高阶像差的分布状况、影响因素及临床意义。方法 :利用基于Tscherning像差原理的Allegrettowaveanalyzer对 78例 ( 14 8眼 )要行LASIK治疗病人进行像差测量 ,其近视等效球镜为 -1 75D～ -10 0 0D ,年龄 19～ 3 6岁。比较眼在 4mm和 7mm瞳孔直径下眼高阶像差的分布及LASIK手术对眼高阶像差的影响。结果 :14 8眼近视者眼高阶像差 (即第三、四、五、六阶像差 )在 7mm瞳孔直径下的均方根值分别为 :RMS3 0 17± 0 0 7、RMS40 14± 0 14、RMS5 0 0 7± 0 0 5、RMS60 0 6± 0 0 6总的眼高阶像差RMSh为 0 2 6± 0 15 ,分别比 4mm瞳孔直径下增加97%、 194%、 110 %和 10 9% ,差别有统计学意义 (P <0 0 1) ;Lasik术后 1个月复查眼高阶像差均有不同程度增加 (从 5 3 %～88% ) ,其中第五阶像差增加最大 ,这会影响术后早期特别是低照明条件下的视力质量。结论 :在正常条件下 (瞳孔直径在 2 5～ 4mm) ,眼高阶像差处于一个低水平 ,随着瞳孔增大 (≥ 7mm )眼高阶像差尤其是球差、慧差成倍增加 ,屈光手术后也有类似情况 ,这将影响眼视觉质量     

SMILE术后视觉质量分析

目的 根据SMILE术矫正近视的初期临床结果,评估其对视力、高阶像差及对比敏感度的影响,分析术前屈光度与术后高阶像差的关系.方法 回顾性病例研究.选择在南京军区南京总医院眼科进行SMILE术的40例近视患者（76眼）.利用iTrace视觉分析仪测量并计算出术前,术后1d、1周、1个月、3个月在小瞳孔（3 mm）及中等瞳孔（5 mm）时的角膜总高阶像差、球差、彗差、三叶草的均方根值（RMS）,并检测屈光度、UCVA、调制传递函数（MTF）值、对比敏感度.对结果数据进行方差分析和直线相关分析.结果 手术后,5 mm瞳孔直径和3 mm瞳孔直径下高阶像差均轻微增高.5 mm瞳孔下,术后1个月总高阶像差、球差RMS值较术前明显增加（P＜0.05）,术后3个月球差RMS值有所增加（P＜0.05）;3 mm瞳孔下,术后1个月球差RMS值与术前相比,差异无统计学意义,术后3个月球差RMS值较1个月时明显增加（P＜0.05）.无论瞳孔大小,术后总高阶像差、彗差、三叶草RMS值与术前屈光度存呈正相关.5、10、15、20、25、30 c/d空间频率下,术后1 d MTF值较术前明显增加,差异有统计学意义（P＜0.01）,术后1周较术后1d有所减少（P＜0.05）.在3、6、12、18 c/d下术后对比敏感度随着随访时间的增加而增加.术中、术后没有发现严重的并发症.结论 SMILE术能有效矫正近视,提高UCVA,但是高阶像差有所增加,尤以球差最明显.术前屈光度越高,手术所导致的高阶像差也越大.     

Effect of brimonidine tartrate 0.15% on night-vision difficulty and contrast testing after refractive surgery

PURPOSE: To evaluate the efficacy of brimonidine tartrate ophthalmic solution 0.15% in patients with night-vision difficulties after laser refractive surgery. SETTING: Center for Refractive Surgery, Walter Reed Army Medical Center, Washington, District of Columbia, USA. METHODS: Six patients with significant night-vision complaints after refractive surgery were enrolled in this study after other treatable causes of night-vision difficulty such as residual refractive error and dry eye were excluded. Low-contrast visual acuity (LCVA) over a range of contrasts (1.25% to 25%) and small letter contrast sensitivity were tested at photopic (100 cd/m(2)) and mesopic (1 cd/m(2)) luminance levels, with and without a standard glare source. Testing was performed before brimonidine tartrate ophthalmic solution 0.15% was administered. Measurements were repeated 1 hour and 1 month after the use of brimonidine tartrate. RESULTS: One hour after using brimonidine tartrate 0.15% solution, patients had significant improvement in LCVA, LCVA with glare, and contrast sensitivity. After 1 month of treatment, all 6 patients reported subjective improvement in night vision and there was a significant difference in performance in mesopic LCVA and mesopic LCVA with glare. The mean pupil size before administration of brimonidine tartrate ophthalmic solution 0.15% was 6.44 mm +/- 1.11 (SD). Pupil size 1 hour after instillation had decreased to 4.53 +/- 1.27 mm and at 1 month had increased to 6.50 +/- 0.94 mm. CONCLUSION: Brimonidine tartrate ophthalmic solution 0.15% improved contrast sensitivity and acuity and decreased night-vision difficulty for up to 1 month in patients with significant complaints after refractive surgery.     

Miotic effect of brimonidine tartrate 0.15% ophthalmic solution in normal eyes

PURPOSE: To evaluate the effect of brimonidine tartrate 0.15% ophthalmic solution (Alphagan P) on pupil diameter in eyes of healthy adults under different luminance conditions. SETTING: Center for Refractive Surgery, Ophthalmology Service, Department of Surgery, Walter Reed Army Medical Center, Washington, DC, USA. METHODS: Using a Colvard pupillometer, the pupil diameter was measured in 15 eyes of 15 healthy adults under 3 luminance conditions (scotopic, mesopic, photopic). The luminance of the room was measured using the Minolta LS-110 Luminance Meter. Pupil diameter was remeasured using the same technique 30 minutes, 4 hours, and 6 hours after administration of 1 drop of brimonidine tartrate 0.15% ophthalmic solution. RESULTS: Under scotopic conditions (luminance 0.0 candelas [cd]/m(2)), the pupil diameter decreased by 1.0 mm or more in 100%, 87%, and 60% of eyes at 30 minutes, 4 hours, and 6 hours, respectively (P<.005); under mesopic conditions (luminance 0.2 cd/m(2)), in 93%, 73%, and 40% of eyes, respectively (P<.005); and under photopic conditions (luminance 150.2 cd/m(2)), in 73%, 87%, and 67% of eyes, respectively (P<.005). CONCLUSIONS: Brimonidine tartrate 0.15% ophthalmic solution produced a significant miotic effect under all 3 luminance conditions. The reproducible miotic effect under scotopic and mesopic conditions may help postoperative refractive patients who report night-vision difficulties related to a large pupil.     

Effect of brimonidine tartrate ophthalmic solution 0.2% on pupil size in normal eyes under different luminance conditions

PURPOSE: To evaluate the effect of brimonidine tartrate ophthalmic solution 0.2% (Alphagan) on pupil size in normal eyes. Three luminance conditions were used to assess the potential use of brimonidine in postoperative refractive patients who experience nighttime vision problems related to large pupil size. SETTING: McDonald Eye Associates, Fayetteville, Arkansas, USA. METHODS: Pupil size was measured in 16 eyes of 16 participants with the Colvard pupillometer under 3 luminance conditions. One drop of brimonidine 0.2% was administered to each patient. Pupil size was then measured using the same technique 30 minutes and 4 and 6 hours after drop administration. RESULTS: Under scotopic conditions, 100% of the pupils showed significant miosis at 30 minutes (P <.05). The effect continued in all eyes for 4 hours. At 6 hours, a miotic effect was still present in 81.3%. However, under photopic luminance, there was no significant effect on pupil size in all 16 eyes (P >.05). The pupil size in 5 eyes (31.2%) was not affected at 30 minutes or 4 or 6 hours. At 6 hours, 15 eyes (93.8%) had returned to their preinstillation size. CONCLUSION: Brimonidine tartrate 0.2% had a significant effect in decreasing pupil size under scotopic conditions. The results indicate that the drug can decrease night-vision difficulties such as halos, star bursts, glare, and monocular diplopia in postoperative refractive patients.     

Efficacy of brimonidine tartrate 0.2% ophthalmic solution in reducing halos after laser in situ keratomileusis

PURPOSE: To quantitatively evaluate the effect of brimonidine tartrate 0.2% (Alphagan) on halo and pupil size in patients who had symptomatic night-vision difficulties after laser in situ keratomileusis (LASIK). SETTING: Nune Eye Hospital, Seoul, Korea. METHODS: This study comprised 28 eyes of 14 patients with symptomatic night-vision difficulties after LASIK. Pupil diameter was measured with a Colvard pupillometer (Oasis Medical, Inc.). Quantitative analysis of halos was performed by measuring the area using a new computerized method. Pupil size and halo size were evaluated under scotopic and normal room light conditions. Alphagan was administered, and the effect was measured after 30 minutes and 1, 6, 12, and 24 hours. RESULTS: There was a statistically significant correlation between pupil size and halo size (r = 0.527; P<.0001; slope = 691.6 pixel/mm). Pupil size and halo size decreased significantly 30 minutes after Alphagan instillation under both luminance conditions (all P< .0001). Under normal room light, the pupil and halo remained decreased until the last measurement at 24 hours. Under scotopic conditions, the pupil returned to its preinstillation size at 24 hours while the halo remained decreased. The maximum effect on halos was observed after 6 hours, when the mean reduction over preinstillation size was 28.2% and 29.1% under normal room light conditions and scotopic conditions, respectively. CONCLUSION: Alphagan effectively reduced halo size and pupil size in postoperative LASIK patients with night-vision symptoms.     

Effect of brimonidine tartrate 0.2% ophthalmic solution on pupil size

PURPOSE: To evaluate the effect of brimonidine tartrate 0.2% ophthalmic solution on pupil size under scotopic and photopic luminance conditions in persons considering laser refractive surgery. SETTING: Ophthalmic Health Center, Tel Aviv, Israel. METHODS: The pupil size was measured in 36 eyes of 36 participants under scotopic and photopic conditions using the Colvard pupillometer (Oasis Medical) before and after brimonidine tartrate drops were administered. The pupil size was subsequently measured after 30 minutes and 4 and 6 hours. RESULTS: No difference was found in pupil size before brimonidine tartrate instillation in eyes with light or dark irides. Before instillation, the mean photopic pupil size was 4.81 mm +/- 0.54 (SD) (range 4.0 to 6.0 mm). At 30 minutes, all pupils became miotic, with a mean size of 3.77 +/- 0.51 mm (range 3.0 to 5.0 mm) (P<.0001). After 6 hours, 27.8% of the pupils had returned to their previous size. Before brimonidine tartrate administration, the mean scotopic pupil size was 6.22 +/- 0.73 mm (range 5.0 to 8.0 mm). There was significant miosis to 4.57 +/- 0.84 mm (range 3.0 to 6.5 mm) (P<.0001) that continued for at least 6 hours. The miotic effect of brimonidine tartrate was stronger in eyes with light irides. CONCLUSIONS: Brimonidine tartrate caused significant miosis, especially under scotopic conditions, most likely from its alpha-2 adrenergic effect. Under photopic luminance conditions, the miotic effect was pronounced.     

Changes in wavefront aberration with pharmaceutical dilating agents

PURPOSE: Finding the best way to capture the wavefronts of small pupils for refractive surgery has become a more pressing issue as the general population ages. This study explores whether pharmaceutical dilation impacts wavefront measurement and pupil centroid. METHODS: Baseline measurements were performed on 32 eyes using the VISX WaveScan Wavefront system. Pupils were dark adapted. One drop of 0.05% tropicamide was placed in each eye, and wavefront measurements were conducted at 10, 20, and 30 minutes. One drop each of 0.5% tropicamide and 2.5% phenylephrine were administered after the measurements. Wavefronts were captured again 30 minutes after the last eye drop. All patients returned for repeated procedures. Wavefront analysis was performed using the same pupillary area as the smallest capture from the same visit. Pupil center shift was taken into account. RESULTS: Mean patient age was 40 +/- 12 years (range: 20 to 59 years). Mean dark-adapted pupil was 6.40 +/- 1.17 mm. Pupil centers shifted randomly after pharmacological dilation compared to the dark-adapted condition. Pupil centers of 45% of the population shifted by > or = 0.2 mm. Repeatability coefficients were established for the wavefront measurements. After controlling for pupil diameter and pupil center, total high order aberrations root-mean-square (RMS) had changed significantly in 18% of the population. The diluted tropicamide formula, which caused less dilation effect, also induced less high order aberration RMS change. CONCLUSIONS: Pharmaceutical dilation agents cause random shifts of the pupil centroid from the dark-adapted pupil condition and could induce changes in wavefront measurements. Caution is required when resorting to dilation to obtain a wavefront measurement of smaller pupils.     

Brimonidine versus dapiprazole: Influence on pupil size at various illumination levels

PURPOSE: To evaluate the influence of dapiprazole versus brimonidine on pupil size at various illumination levels. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. METHODS: In randomized prospective study, 19 healthy volunteers received 2 ophthalmic solutions, dapiprazole and brimonidine, 1 in each eye, for intraindividual comparison. Before and after application, pupil diameter was measured using an infrared binocular pupillometer at 3 illumination levels (0.03, 0.82, and 6.4 lux). RESULTS: Only slight pupil dilation was observed under scotopic conditions after application of both agents. After 20 minutes, the median reduction in pupil width was 1.4 mm for brimonidine and 0.9 mm for dapiprazole. These effects were statistically significant for both agents (both P < .001). The maximum effect was observed after 40 minutes and remained stable through the next measurement at 180 minutes. Under mesopic lighting conditions, only a slight effect (<1 mm) was seen. CONCLUSIONS: Pupil mydriasis at scotopic illumination levels was reduced by both drugs in a similar fashion. Because of the slightly stronger effect of brimonidine, application of this agent 20 minutes before activities in dimly lit areas or at night may be recommended for photic phenomena following refractive surgery.     

准分子激光原位角膜磨镶术对托吡卡胺角膜渗透性的影响

目的:探讨准分子激光原位角膜磨镶术(laser in situkera-tomileusis,LASIK)对托吡卡胺角膜渗透性的影响。方法:对34例(64眼)接受LASIK治疗的近视眼患者,于术前和术后1mo测量并比较10g/L托吡卡胺扩瞳后5,10,15,20min以及25min时的瞳孔大小,并记录瞳孔达到6mm大小所需时间。结果:平均中央角膜厚度由术前555.4±32.3μm下降至术后475.6±33.5μm,差异有显著意义。术后1mo10g/L托吡卡胺扩瞳后10,15,20min时的瞳孔直径明显大于术前相应时间点的瞳孔大小,而5,25min时的瞳孔大小无显著性差别。瞳孔达到6mm大小所需平均时间由术前14.66±4.28min减少至12.42±2.16min。结论:LASIK术后托吡卡胺的扩瞳作用显著加快。LASIK导致的角膜变薄增强了托吡卡胺的角膜渗透性。     

兔眼准分子激光原位角膜磨镶术后托吡卡胺滴眼前房浓度的改变

目的探讨准分子激光原位角膜磨镶术(LASIK)对托吡卡胺角膜通透性的影响。方法 24只新西兰白兔24只眼施行LASIK手术,于术前和术后30 d测量并比较1%托吡卡胺滴眼液扩瞳后10、15、30 min以及1、2h时的瞳孔大小,记录瞳孔达到6.0 mm大小所需时间,高效液相色谱法(HPLC)测量扩瞳后15 min托吡卡胺的房水浓度。结果术后30 d 1%托吡卡胺滴眼液扩瞳后15、30 min及1 h时的瞳孔直径明显大于术前对应时间点的瞳孔大小,而10 min以及2 h时的瞳孔大小无显著性差别;瞳孔达到6.0 mm大小所需平均时间由术前(16.40±4.28)min减少至(14.06±2.36)min;术后30 d托吡卡胺的房水浓度高于术前对应时间点。结论 LASIK术后托吡卡胺的前房浓度增加。LASIK导致的角膜生理特性的改变增强了托吡卡胺的角膜通透性。     

Effect of brimonidine tartrate 0.15% on scotopic pupil: controlled trial.

PURPOSE: The aim of this study was to evaluate the duration of the effect of one single dose of brimonidine tartrate 0.15% on pupil diameter, under scotopic conditions, when applied topically in 1 eye of normal subjects. METHODS: The eyes of 19 normal volunteers were randomized so that 1 eye had 1 drop of brimonidine tartrate 0.15% and the other received no medication. Pupil diameter was measured using an infrared pupillometer. The first measure was obtained before the instillation of brimonidine. After that, four measures, with 2-h intervals, were performed. RESULTS: From 19 participants, 14 were women and 5 were men, with a mean age of 25.05 years (standard deviation, +/- 6.98). Before brimonidine instillation, mean pupil diameter in the control eyes was 5.11 mm, and in the brimonidine eyes it was 5.15 mm. After 8 h, the mean pupil size was 4.01 mm in the treated eyes, and 4.56 mm in the untreated eyes. There was a tendency of miotic effect to be more important on the treated eye, as compared to the control eye in all intervals, but this did not reach statistical significance (P = 0.375). When comparing both eyes, independently of the periods, the treated eye had a smaller diameter than the untreated eye (P = 0.038). The miotic effect was observed for at least 8 h after instillation. CONCLUSIONS: Miotic response of brimonidine tartrate 0.15% lasted for at least 8 h and has a significant effect on the nontreated eye.