Modified Scleral Flap Incision to Reduce Corneal Astigmatism after Intraocular Lens Implantation

To investigate a simple method during extracapsular cataract extraction with posterior chamber intraocular lens implantation in order to reduce surgically induced corneal astigmatism.Methods: A modified scleral flap incision was used in the extracapsular cataract extraction with intraocular lens implantation and the postoperative changes in conreal astigmatism was observed.Results: The peak value of postoperative corneal astigmatism was 3. 60 D, and the corneal astigmatism regression was 2. 11 D, surgically induced astigmatism was less significant in modified scleral flap incision group than that in conventional limbal incison group (P<0. 05).Conclusions: The modified scleral flap incision is an ideal incision for cataract extraction with intraocular lens implantation when phacoemulsifier is not available. Eye Science 1995; 11-. 136-139.     

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     

同轴微切口超声乳化手术对白内障的治疗效果及术后影响

目的：分析同轴微切口超声乳化手术对白内障的治疗效果及术后影响,探讨其临床应用价值。

方法：将300例300眼接受超声乳化手术治疗的白内障患者随机分为观察组和对照组,各150例150眼。观察组患者采用同轴微切口超声乳化手术治疗,对照组患者则采用传统同轴常规切口超声乳化手术治疗。对比分析两组的有效超声乳化时间(effective phaco time,EPT)、平均超声能量(average ultrasound energy,AVE)、术中前房稳定性、术后恢复时间,以及术前和术后1d,1wk,1、3mo时测得的裸眼视力(UCVA)、手术源性角膜散光度数及角膜内皮细胞丢失程度。

结果：两组EPT、AVE及术中前房稳定性均无明显统计学差异(P>0.05)。术前两组UCVA、角膜散光度数及角膜内皮细胞计数均无显著统计学差异(P>0.05)。观察组患者术后恢复时间明显短于对照组,差异有统计学意义(P<0.05)。与对照组比,观察组患者术后1d,1wk,1mo时UCVA均明显较好,差异有统计学意义(P<0.05); 术后1wk,1、3mo时,手术源性角膜散光度数均明显较低,差异有统计学意义(P<0.05); 术后1d,1wk,1、3mo时,角膜内皮细胞丢失率均明显较低,差异有统计学意义(P<0.05)。两组术后各时间点比较,UCVA、手术源性散光度数及角膜内皮细胞丢失率均有显著统计学差异(P<0.05)。

结论：同轴微切口超声乳化术治疗白内障,术后视力恢复快,角膜散光小,角膜内皮细胞丢失程度低,临床应用价值相对较高。     

Factors associated with corneal astigmatism change after ptosis surgery

AIM: To evaluate the predictive factors of postoperative corneal astigmatism change in ptosis patients who underwent ptosis surgical repair. METHODS: Patients who underwent levator resection at Oculoplastic service of the Department of Ophthalmology, Naresuan University Hospital, Thailand between September 2017 and August 2019 were retrospectively evaluated. Changes in degree and axis of corneal astigmatism after ptosis surgery were compared based on patient factors consisting of age at operation, sex, preoperative margin-reflex distance (MRD) 1, and preoperative degree and axis of corneal astigmatism. RESULTS: Forty-two eyes of 28 patients were included in the study. Wilcoxon signed ranks test showed a significant postoperative corneal astigmatism change only in a subgroup of eyes with preoperative astigmatism of ≥1.5 diopters (D; P=0.006). Furthermore, 72.2% (13/18) of the eyes with preoperative astigmatism of ≥1.5 D showed a reduction of astigmatism after eyelid surgery, with the mean astigmatic change of 0.65 D. Majority of preoperative eyes demonstrated with-the-rule astigmatism pattern (45.2%), of which 57.9% showed a reduced degree of astigmatism. CONCLUSION: In patients undergoing ptosis surgery, the data demonstrate for the first time the association between postoperative corneal astigmatism change and a preoperative corneal astigmatism of ≥1.5 D. Thus, we encourage considering severity of corneal astigmatism prior to cataract or refractive surgery planning in ptosis patients, especially with toric-intraocular lens, to avoid the possibility of calculation error.