RGPCL矫正60例中低度近视的初步观察

目的评价高透氧性硬性角膜接触镜(RGPCL)矫正控制中低度近视屈光不正的效果。方法采用RGPCL矫正120眼中低度近视性屈光不正,统计矫正后当天、1年时近视屈光度、散光度的变化。结果观察组的近视度和散光度随戴镜时间延长相对稳定。结论RGPCL对中低近视的度数控制有效。     

Proximity factor in image size magnification for optical instruments in general

A general expression is derived for the proximity factor in near image size magnification for an arbitrary instrument in front of an arbitrary eye. The proximity factor is a 2 x 2 matrix. The instrument and eye may be astigmatic and have decentred elements. The image on the retina may be blurred or not. The analysis is exact within the limitations of linear optics. The general results are specialized for the case of a stigmatic instrument and a stigmatic eye. The results are applied to the case of a thick, possibly bitoric, spectacle lens. The Appendix treats two numerical examples.     

Contact lens fitting following corneal graft surgery

Contact lens fitting may be required following keratoplasty for either optical or thera‐peutic reasons. Optical indications for contact lens fitting include the correction of irregular astigmatism, high regular astigmatism, anisometropia and secondary aniseikonia, as well as simple ametropia, where the patient desires to wear contact lenses in preference to spectacles. Therapeutic lenses are not routinely fitted following kerate plasty, although this management is advised in certain cases, such as when there are protruding sutures or epithelial healing is impaired. Designing a contact lens for a patient who has undergone keratoplasty will require the practitioner to carefully assess all the relevant features of the corneal graft. In this regard, there are many factors that need to be considered including the diameter of the graft zone, the topographical relationship between the host cornea and donor cornea, the corneal (graft) toricity and the location of the graft. Special designs, such as reverse geometry lenses, or more complex contact lens modalities, such as piggyback contact lens systems, may be required to achieve success in fitting.     

准分子激光屈光性角膜切削术治疗近视和近视散光3年疗效分析

目的 :评价准分子激光角膜切削术 (photorefoactivekeratecomy ,PRK)治疗近视、近视散光的远期疗效。方法 :按术前屈光度将 2 0 9例 (3 77例 )屈光度为 - 1 5 0～ 1 6 0D的患者分为二组 ,低中度组 (I组 )为 - 1 5 0～ - 6 0 0D(2 3 8眼 ) ,高度组 (II组 )为 - 6 2 5～ - 1 6 0 0D(1 3 9眼 )。应用美国Visx2 0 /2 0准分子激光仪对上述二组患者行PRK治疗 ,并对患者术后 3年的屈光度、视力、角膜屈光力、角膜厚度、并发症进行随访观察。结果 :I组、II组中屈光度 <± 1D者分别占 94 5 %和 6 1 9% ;≥± 2 0 0D分别占 0 % ,2 3 7%。术后裸眼视力≥ 0 5者在I组、II组中分别占 99 6 %和 79 9% ;≥ 1 0者分别占 85 3 % ,48 2 %。角膜屈光力两组均在术后 6个月稳定 ,角膜上皮下雾状混浊O级在I组、II组分别为1 0 0 %和 98 6 % ,术后眼压两组均正常。结论 :准分子激光屈光性角膜切削术治疗近视、近视散光效果肯定 ,尤对低中度患者疗效更佳     

抗青光眼术后的白内障摘除术对角膜高度散光的矫正

目的：探讨抗青光眼术后的白内障摘除术根据术前角膜散光轴向选择不同位置切口对角膜高度散光的矫正效果。方法：伴有角膜高度散光的34例(34眼)抗青光眼术后行白内障囊外摘除加后房型人工晶状体植入术患者，根据术前角膜散光轴向选择白内障切口位置，同时保护原有滤过泡。观察术后1W、4W、12W和24W角膜散光度的变化情况。结果：术后1W、4W、12W、24W角膜散光度较术前降低，差异有显著性(P=0．003，0．010，0．(109，0．011)；术后1W、4W、12W和24W角膜散光度相比差异无显著性(P=0．121)。结论：抗青光眼术后的白内障摘除术选择不同位置切口所产生的手术性散光使切口方向上的屈光力减少，而使与其垂直轴向上屈光力增加，从而在一定程度上矫正术前角膜高度散光。     

两种微角膜刀所制角膜瓣对LASIK术后角膜循规性散光的影响

目的　探讨两种微角膜刀所制角膜瓣对LASIK术后角膜循规性散光的影响。方法　循规性近视散光患者 96人 ( 180眼 )随机分为Ⅰ、Ⅱ两组 ,分别采用MoriaLSK -One平推式气动微角膜刀和MoriaM 2旋转式微角膜刀制做角膜瓣 ,然后进行激光手术。术后 6个月观察患者的角膜散光及角膜散光轴的变化。结果　术后 6个月 ,Ⅰ组、Ⅱ组角膜散光值分别为 0 3 6± 0 13D和 0 5 2±0 0 9D ,与术前相比 ,分别下降 1 3 5± 0 11D ,1 0 8± 0 10D ,差异显著 (P <0 0 1)。而散光轴无明显改变。结论　与MoriaLSK -One平推式气动微角膜刀相比 ,MoriaM 2旋转式微角膜刀所制角膜瓣有产生循规性角膜散光的趋势     

Surgical approaches to correct corneal astigmatism at time of cataract surgery: a mini-review

Among refractive errors, astigmatism is the most common optical aberration, where refraction changes in different meridians of the eye. It causes blurred vision at any distance and includes corneal, lenticular, and retinal astigmatism. Cataract surgery used to cause a progressive increase in the pre-exisiting corneal astigmatism because of creating a surgically induced astigmatism, for example, a large size surgery incision. The development of surgical techniques during last decades has made cataract surgery interchange to treat preoperative corneal astigmatism at time of surgery. Nowadays, three surgical approaches can be used. By placing a sutureless clear corneal incision on the steep meridian of the cornea, a preoperative corneal astigmatism less than 1.0 D can be corrected. Single or paired peripheral corneal relaxing incisions (PCRIs) provide 1.0-3.0 D corneal astigmatism correction. PCRIs are typically used for treating 1.0-1.5 D of regular corneal astigmatism, if more than 2.0 D, the risk of overcorrection and irregular astigmatism is increased. When toric intraocular lenses (IOLs) are unavailable in markets, PCRIs are still a reasonable option for patients with up to 3.0 D of pre-existing corneal astigmatism. Toric IOLs implantation can correct 1.0-4.5 D of corneal astigmatism. Several IOLs are approved to correct a high degree of corneal astigmatism with cylinder power up to 12.0 D. These approaches can be used alone or in combination.     

PRK治疗复性近视散光效果分析

目的探讨PRK治疗复性近视散光的临床疗效.方法按术前欲矫正球镜屈光度将88眼分为A(≤-6D,62眼)、B(≥-6.25D,26眼)两组,回顾性分析随访1年后的残留球镜度、散光度和非矫正视力情况.结果术后B组球镜度仍高于A组(-0.83D和-0.44D,P=0.0005).两组除术后3个月时,手术前后散光度均无明显差别(P>0.05).两组间非矫正视力在整个随访期间差别均有非常显著性意义(P<0.01).结论由于对高度近视矫正得不够彻底,PRK仅对球镜度低于-6D以下的复性近视散光疗效确切.     

屈光参差性弱视儿童视网膜光学相干断层成像研究

目的：应用视网膜光学相干断层成像方法（OCT）研究屈光参差性弱视儿童视网膜神经纤维层（RNFL）和黄斑中心凹厚度,探讨弱视的发病机制。方法对屈光参差性单眼弱视儿童38例进行OCT检查,据弱视眼屈光状态分为远视散光弱视组18例,单纯远视弱视组20例,对侧健眼为正常对照组。分析比较三组视盘周围RNFL厚度和黄斑中心凹厚度的差异。结果远视散光弱视组、单纯远视弱视组和正常对照组视盘周围RNFL厚度分别为115.77±13.42μm、111.34±10.30μm 和103.05±11.10μm,黄斑中心凹厚度分别为198.86±28.30μm、191.98±27.81μm,181.18±29.06μm。两弱视组分别与正常对照组、两弱视组组间比较视盘周围RNFL厚度及黄斑中心凹厚度,差异均有统计学意义,P＜0.05。结论屈光参差性弱视其弱视眼视盘周围RNFL厚度及黄斑中心凹厚度较对侧正常眼增厚,且远视散光弱视眼厚于单纯远视弱视眼。