PTK+PRK治疗LASIK术中角膜瓣碎裂

目的研究激光辅助原位角膜磨镶术(LASIK)手术过程中,角膜瓣碎裂的处理及临床结果与疗效。方法对开展LASIK手术过程中,发生角膜瓣碎裂者行PTK(激光治疗性角膜切除术) PRK(激光屈光性角膜切削术),包括视力、屈光状态及术后Haze(混浊度)的情况,随访1周、1月、3月、6月、1年。结果自2000年5月～2004年5月共进行LASIK手术7 858眼,发生角膜瓣碎裂11例14眼,对其中7例8眼行PTK PRK。术后1周最佳矫正视力均大于0.6,Haze 0级;术后1月视力均大于1.0,Haze大于1级;术后3月、1年视力均大于1.0,Haze0级。结论PTK PRK治疗LASIK术中角膜瓣碎裂安全有效。     

屈光性角膜手术26743例的临床分析

目的总结准分子激光屈光性角膜手术10年的临床效果。方法1993年5月至2003年5月包括行PRK,LASEK及LASIK的患者共26743例,44580眼,应用数学模式建立数据库,进行数据统计分析。结果男14691眼,女29889眼;年龄9～57岁平均27.2岁;左22443眼,右22137眼。术前裸眼视力0.10±0.07;矫正视力0.98±0.37,其中≥0.543794眼,占98.2%,≥1.041066眼,占92.1%,≥1.52218眼,占5%;眼压15.76±7.25;屈光度球镜-0.75～-18.00D(-5.65±3.24D),柱镜-0.25～-5.00D(-0.051±0.77D);角膜曲率(K)值K143.94±3.57,K242.98±3.50。筛选圆锥角膜0.99%,亚临床圆锥角膜0.93%;眼底病变及视网膜周边变性0.39%,排除系统疾病及不宜行激光手术者。术后裸眼视力0.98±0.34,其中≥0.544580眼,占100%,≥1.044031眼,占98.8%,≥1.54732眼,占10.61%;矫正视力1.03±0.33;眼压14.87±7.06;屈光度球镜-0.001±0.058D,柱镜-0.000±0.027D;K值K138.07±9.83、K237.20±10.84。实际矫正度在预期矫正度±1.00范围内98.7%。临床、亚临床圆锥角膜及眼底病变者不手术;视网膜周边变性眼底激光1月后可手术,以LASEK为主。3种手术长期效果没有统计学差异。PRK1周内基质细胞明显减少,10d、1月基质细胞数量增加,3月减少,6月后逐渐恢复正常;LASIK各时间点角膜细胞变化     

Rose-k对临床期乳头型圆锥角膜矫正效果研究

目的：研究透气性硬性角膜接触镜Rosek对临床期乳头型圆锥角膜的矫正效果。方法：应用TMS IV角膜地形图仪将确诊为临床期乳头型圆锥角膜的患眼35例（轻度组15眼、中度组10眼、重度组10眼）,验配透气性硬性角膜接触镜Rosek（Rose-k）,并与其裸眼及配戴框架眼镜（SP）进行矫正视力的对比,1年内定期观察患眼的配适状态、角膜反应情况、矫正视力以及应用绝对等级角膜地形图比较分析患眼配戴Rose—k前后角膜中央曲率、锥顶曲率、最大子午线屈光度第6-8环的平均值（KS）、子午线屈光度第6-8环的平均值（AVERK）、角膜散光（CYL）、角膜表面非对称性指数（SAI）、角膜表面规则性指数（SRI）等各参数的变化,分析Rose—k对临床期乳头型圆锥角膜的矫正效果。结果：配戴框架眼镜的患眼矫正视力≥0．6者占35．0％,配戴Rose—k的患眼矫正视力≥0．6者占91．4％;配戴框架眼镜的患眼矫正视力≥1．0者占8．6％,配戴Rose—k的患眼矫正视力≥1．0者占31．4％。32眼（91．4％）为理想或可接受的三点接触的配适状态,3眼（8．6％）为可接受的两点接触的配适状态。配戴Rosek一年后,轻、中、重三组患眼的角膜中央曲率、锥顶曲率、KS值、AVERK值均有显著下降,轻度组患眼的CYL有显著下降,中、重组患眼的CYL呈下降趋势,但统计学无意义,轻、中、重三组患眼的SAI及SRI亦呈下降趋势,但统计学无意义。所有患眼均无严重并发症出现,配戴Rose—k前已出现的角膜斑翳无进一步加深,镜片的舒适度得到了每例患者的认可。结论：临床期乳头型圆锥角膜的患眼配戴Rosek不仅能获得理想的矫正视力、良好稳定的配适状态、舒适度和安全性,而且对病变区的角膜形态有明显的改善作用,值得临床推广。     

长期配戴角膜接触镜使角膜中央厚度变薄

目的：探讨长期持续配戴软性角膜接触镜者和长期配戴硬性透氧性接触镜者与无角膜接触镜配戴史者中央角膜厚度的差异。方法：应用超声角膜测厚仪检测无角膜接触镜配戴史者500例（918眼）、长期持续配戴软性角膜接触镜2年以上200例（386眼）和长期配戴RGP≥1年者100例（195眼）的中央角膜厚度。结果：无角膜接触镜配戴史者,平均角膜中央厚度为（528．5923．37）μm,长期持续配戴软性角膜接触镜者,平均中央角膜厚度为（512．31±21．73）μm,配戴RGP者平均中央角膜厚度为（515．03±22．97）μm。配戴软性角膜接触镜者与正常者比较,差异有显著性（P〈0．05）。配戴RGP者与正常者比较,差异有显着性（P〈0．05）,配戴软性角膜接触镜者与RGP者比较,差异无显著性（P〉0．05）。结论：长期持续配戴软性角膜接触镜者和RGP者平均中央角膜厚度均薄于无角膜接触镜配戴者。     

PureVision纯视角膜接触镜的治疗应用观察（上）

目的：评估博士伦PureVision纯视连续过夜配戴接触镜的治疗应用的指征与效果。方法：非随机选用中山眼科中心门诊与住院病例29例31眼．包括需要缓解疼痛与刺激症．保护角膜和促进角膜创面愈合等病例。采用PureVision纯视镜片连续过夜配戴治疗的同时．根据眼病性质、局部适当给予抗生素或人工泪液,定期检查或询问疼痛缓解情况、眼部改变、镜片的配适状态、镜片沉淀物以及眼部并发症。结果：病例共29例（31眼）．观察时间3～57天,平均209天。眼病包括大泡性角膜病变（6例6眼）．角膜炎合并小穿孔或后弹力层膨出5例（5眼）．化学烧伤上皮缺损6例（7眼）。角膜移植术或创伤缝线刺激3例（3眼）。丝状角膜炎3例（3眼）,角膜上皮糜烂2例（3眼）．反复性角膜上皮剥脱症1例（1眼）。角膜板层裂伤与上皮缺损1例（1眼）．外伤性白内障摘除术后持续上皮溃疡1例（1眼）,角膜缘移植＋羊膜移植术后1例（1眼）。用于缓解疼痛与刺激症为目的者21例（22眼）,疼痛完全缓解或部分缓解达1。0％。促进角膜愈合者20例《22眼）j完全治愈15例（16眼）占72．7％．部分改善者4例（5眼）占227％。绷带保护角膜作用21例（23眼）,其中20例22眼（957％）均有满意的保护作用,仅1例因配适不良无效。结论：结果表明,PureVision纯视角膜接触镜对于多种角膜病、眼表病及角膜术后角膜保护、促进角膜愈合和缓解疼痛刺激等有显著疗效：镜片具有高透氧性能及抗沉淀性好,可大大减少眼部并发症发生的危险．这种新型的镜片可作为理想首选的治疗性应用镜片。     

高度近视白内障患者A超／角膜曲率计和IOL-Master人工晶状体度数的测量比较

目的：通过研究接触式A超和新型非接触式光学相干生物测量仪IOL—Master两种方法测量高度近视白内障患者眼轴长度的特点,比较两种方法的准确性,探讨其对轴性高度近视眼合并白内障IOL度数的准确预测是否有指导意义。方法：分析2008年8月～2009年4月在我院行白内障超声乳化摘除及人工晶状体植入术的高度近视20例（26眼）白内障患者,术前分别用A超和IOL—Master两种方法测量其眼轴长度（L）,用角膜曲率计和IOL—Master测量其角膜曲率（K）,用SRK／T公式计算人工晶状体的度数,在患者术后3个月随访验光,检查患者的屈光状态。结果：A超测量的眼轴为（28．45±2．01）mm,范围在25．44～32．53ram;IOL-Master为（28．85±2．05）mm,范围在25．36～32．82mm;角膜曲率计测量的角膜曲率为（44．06±1．41）D,范围在41．5～46．5D;IOL—Master测量的角膜曲率为（44．48±1．54）D,范围在41．28～47．19D。术后3个月绝对屈光误差≤±0．50D者,接触式A超测量的有8例,IOL-Master测量的有13例;绝对屈光误差≤±1．OOD者,接触式A超测量的有18例,IOL—Master测量的有17例。经人工晶状体植入术治疗高度近视的患者用A超和IOLMaster两种方法测得的眼轴长度存在差异,术后绝对屈光误差也存在明显差异。结论：眼轴增加是高度近视合并白内障超声乳化联合囊袋内人工晶状体植入术术后屈光度误差的主要原因,提高其眼轴测量的准确性是减少术后屈光度误差的关键。IOLMaster为我们提供了生物学测量的新选择,对高度轴性近视白内障手术人工晶状体的选择有重要意义。     

硬性透气性角膜接触镜对散光性弱视的矫治作用

目的：评价硬性透气性角膜接触镜（rigid gas permeable contactlens,RGPCL）对儿童散光性弱视的矫治作用及其安全性。方法：选取框架眼镜矫治效果欠佳的儿童散光性弱视23例（46眼）,其中,单纯远视性散光5眼,复合远视性散光23眼,复合近视性散光14眼,混合散光4眼。依据框架眼镜矫正视力分为轻度弱视组（13眼）,中度弱视组（22眼）,重度弱视组（11眼）。所有患儿配戴高透气性RGPCL,随访12个月,观察其矫治作用。结果：配戴RGPCL即时,矫正视力较框架眼镜提高1～4行,平均（2．7±0．9）行,达到或超过5．0者7眼（15．22％）。12个月后,28眼（60．87％）的矫正视力≥5．0,其中,轻度弱视组11眼（84．62％）,中度弱视组17眼（77．27％）,重度弱视组无一眼达到5．0。观察期内无严重角、结膜损伤以及感染等并发症发生,无因不能耐受而停戴者。     

高透氧性硬性角膜接触镜对青少年屈光参差性弱视的矫正作用

目的：评估高透氧性硬性角膜接触镜治疗青少年屈光参差性弱视的疗效。方法：为符合屈光参差性弱视诊断标准的35例患者,按规范的验配程序配戴RGP,分别比较配戴RGP前后的弱视眼矫正视力,以及随访1月、6月和1年后的弱视眼治疗效果。结果：在配戴RGP后,有74％的患者弱视眼矫正视力优于框架眼镜,随访第1个月、第6个月、1年后弱视眼矫正视力随着配戴时间延长逐渐提高,配戴1年后弱视治疗有效率达100％,治愈率达88．6％。弱视眼在配戴RGP后,以及随访1月、6月、1年后的矫正视力和框架眼镜均存在显著性差异（p〈0．05）,且随访1月后100％患者均感配戴舒适,随访期间未发现严重的接触镜并发症。结论：高透气性硬性角膜接触镜基于其优越的像质和并发症少等优点,是一种安全有效的青少年屈光参差性弱视的治疗方法。     

气相色谱-脉冲火焰光度法测定水产品中有机锡的研究

目的建立气相色谱-脉冲火焰光度法（GC—PFPD）测定水产品中有机锡的研究。方法以氢溴酸＋四氢呋喃（1＋20）和0．03％环庚三烯酚酮-正己烷为萃取剂,凝胶渗透色谱法（GPC）净化,戊基溴化镁衍生后弗罗里硅土柱净化,气相色谱-脉冲火焰光度检测器（硫模式）检测。结果8种有机锡组分及内标分离良好,各组分相对响应因子的相对标准差（RSD）〈15％,2种基质3个水平加标的平均回收率为84．1％～116．6％,兄如小于20％,标准参考物（ERM—CE477）中3种丁基锡测定结果与定值一致。结论气相色谱-脉冲火焰光度检器测定法满足了水产品中多组分有机锡痕量检测的需要。     

超声波法制备两性壳聚糖衍生物及其抗菌性能

应用超声波辐射的方法,使壳聚糖和氯乙酸在Na0H-乙醇体系中反应,制备0-羧甲基壳聚糖（OCMC）．测定了四因素三水平正交试验中的羧甲基取代度（DS）和氨基（N2-）保留量（％）,优化了实验条件．选择较好的OCMC,以乙醇为溶剂,在超声波辐射下,通过和2,3一环氧丙基三甲基氯化铵（GTA）反应,合成具有抗菌性能的两性的季铵化D羧甲基壳聚糖（QOCMC）,并测定其季铵化取代度．红外光谱仪表征了其峰值的变化,扫描电镜表征其晶态结构的变化．通过对大肠杆菌和金黄色葡萄球茵最低抗茵浓度测试,得到QOCMC的最低抑茵浓度为OCMC的1／8,表明QOCMC的抗茵性能优于OCMC．     

A return to primitive practice? Radial keratotomy revisited

Recently, a refractive surgeon was quoted in the national and professional press as proposing that radial keratotomy (RK) is to be preferred over laser procedures, such as photorefractive keratectomy (PRK) and laser assisted in situ keratomileusis (LASIK). The rationale for this public recommendation was that the RK procedure achieves better visual results and fewer complications than the laser procedures. Peer reviewed literature on these refractive procedures was surveyed to establish the validity of such a statement and it was found that current data do not support the notion that RK results in better visual outcomes than PRK and LASIK The true incidence of complications is difficult to establish. However, when the post procedure chronic effects are compared between RK, PRK and LA SIK, it becomes apparent that the post-RK patient pays the highest price, by a large margin, in visual quality impairment and corneal health. Although the visual acuity outcomes for low to moderate myopes, when corrected by any of the three refractive procedures considered here, are not dramatically different, we concluded that RK is not the preferred methodology because of its associated chronic visual and corneal health complications.     

Permavision intracorneal inlay after sixteen years. Regression of initial refractive hyperopia

According to the available scientific literature, 77 patients underwent Permavision inlay worldwide, between 2004 and 2007. This study reported about the use of Permavision intracorneal inlay to increase the central corneal curvature and to correct hyperopia. A 32-year-old male patient went to the Tecnolaser Clinic Vision ® facilities for a refractive study. Preoperative refraction without cycloplegia was +6.00 D in the right eye (RE) and +4.00 in the left eye (LE). The surgery was performed for both eyes on December 2, 2003. The Carriazo-Barraquer mechanical microkeratome (Moria) was used to create a 180 μm-thick corneal flap with a diameter of 8.5 mm. After lifting the flap, the corneal inlay was placed centrally above the pupil and the flap was re-positioned. In this case report, the patient reverted to the initial refractive situation. The first refractive regression appeared at twelve-month follow-up. After sixteen years, it was found a decrease in maximum corneal curvature, an increase in mean corneal densitometry percentage, and no important changes in the central corneal thickness. In the reported case, the cornea reverted to its original shape. In the scientific literature, this is the first case report of a non-explanted Permavision inlay after sixteen years.     

Corneal morphology and visual outcomes in LASIK patients after orthokeratology: A pilot study

A statement of Significance

For the first time, this study shows that corneas that previous undergone orthokeratology treatment do not respond differently to LASIK compared with previous soft contact lens wear experience.

Accelerated versus standard corneal collagen cross-linking in pediatric keratoconus patients: 24 months follow-up results

Purpose

To compare the 24 month visual, refractive, topographic and aberrometric results of the accelerated and standard corneal collagen cross-linking (CXL) in pediatric keratoconus patients.

The AS biometry technique--a novel technique to aid accurate intraocular lens power calculation after corneal laser refractive surgery.

Intraocular lens power (IOL) calculation for cataract surgery has been shown to be inaccurate after photorefractive keratectomy (PRK), laser-assisted subepithelial keratectomy (LASEK) and laser in situ keratomileusis (LASIK). Many techniques exist to calculate corneal power with varying results and require the clinician to be aware of the pitfalls of IOL power calculation in post-refractive eyes. The AS biometry method proposed here is a simple method which does not rely on the calculation of corneal power. This new method is compared to the current gold standard the clinical history method (CHM). Twenty-nine eyes of 15 patients had routine biometry prior to LASIK, LASEK or PRK. The range of pre-operative spherical equivalent refractive error was -5.37 to +4.00 diopters. The post-operative refraction was measured at 3-6 months. The IOL power calculation was calculated using the AS biometry method and the CHM. The two methods were compared using the Student's paired t-test and the Bland Altman technique. There was no statistical difference between the AS biometry method and the CHM. The paired Student's t-test comparing the AS biometry method and the CHM showed no statistical difference, t=0.33 with a p-value of 0.75, at a 95% confidence interval. The authors conclude that the AS biometry technique is as accurate as the CHM. The former is a simpler method which avoids many of the pitfalls and confounding factors involved in IOL power calculation following corneal excimer laser surgery. However, like the CHM it requires measurements prior to laser surgery.     

The use of the Ocular Response Analyser to determine corneal hysteresis in eyes before and after excimer laser refractive surgery

Purpose

To compare corneal biomechanical parameters and two measures of intraocular pressure (IOP) in eyes before and after excimer laser refractive surgery, with the Ocular Response Analyser (ORA).

Materials and methods

Eighty normal eyes of 41 patients undergoing excimer laser refractive surgery in Birmingham, U.K. were recruited into three groups: Laser Assisted-Epithelial Keratomileusis (LASEK) (Myopes), Laser Assisted in Situ Keratomileusis (LASIK) (myopes) and LASIK (hyperopes). The preop and 3 months postop Goldmann correlated IOP (IOPg), corneal compensated IOP (IOPcc), corneal hysteresis (CH), and corneal resistance factor (CRF) were measured by the ORA. Central corneal thickness (CCT) was measured using ultrasonic pachymeter. The differences of the changes in IOPg, IOPcc, CH, CRF and CCT between the three groups were estimated. A General Linear Model was selected to investigate the influence of gender, age, initial conditions (CH, CRF, CCT, IOPcc and IOPg) and changes in CCT on the measured IOP.

Results

The differences between the mean IOPg, CH and CRF after refractive surgery were statistically significant for all three groups. The hyperopic LASIK group had a significantly smaller change compared to the other groups (which had no statistical significance). The preop IOPg, preop CH and gender were significant predictors of the changes in measured pressure and biomechanical parameters after surgery in the myopic groups only.

Conclusion

CH and CRF were found to decrease after both myopic and hyperopic refractive surgery. CH and CRF measurement may prove important tools to clarify the role of corneal biomechanics for refractive surgery.     

Contact lens complications among wearers in Ghana

PurposeContact lens (CL) practice is relatively new in Ghana; a country where the geographical location (warm climate) lends itself to harsh environmental conditions (high humidity) known to influence CL wear. Recent studies suggest an increase in CL wear (corrective and cosmetic), yet, there are no studies about CL-related complications. This study sought to determine the complications associated with CL wear in Ghana.MethodsThis was a retrospective cohort study. The medical records of contact lens wearers from five CL clinics in the two largest metropolises in Ghana, Accra and Kumasi, were reviewed. Included in the study were records of individuals who visited the clinics within the period of 2013–2016. Data on patients with contact lens-related complications were analyzed.ResultsThe prevalence of CL complications was 29.06 %. The mean ± SD age of patients with CL complications was 35 ± 15 years. Contact lens complications were more common in females (52.90 %). The majority of complications were in soft contact lens wearers (82.35 %). Refractive error correction was the most common indication for CL wear (61.76 %) among those with complications, followed by keratoconus (14.71 %), scarred blind eye (14.71 %), corneal ulcer (5.88 %) and anterior staphyloma (2.94 %). Contact lens complications reported were giant papillary conjunctivitis (41.18 %), corneal infiltrates (23.53 %), bacterial keratitis (14.71 %), corneal abrasion (11.76 %), dry eye (5.88 %) and corneal oedema (2.94 %). The causes of CL complication were inappropriate lens cleaning (29.41 %), poor hygiene (23.53 %), overnight contact lens wear (17.64 %), poor lens fit (14.71 %) and reaction to contact lens solution (14.71 %).ConclusionContact lens complications were more common in soft contact lens wearers in Ghana. Giant papillary conjunctivitis was the most common contact lens complication reported. Adherence to CL wear care regimen and good personal hygiene may prevent the majority of CL complications observed in Ghana.     

Quantitative assessment of post-LASIK corneal infiltration with frequency domain anterior segment OCT: A case report

We present the use of frequency domain (FD) optical coherence tomography (OCT) for quantitative assessment of the infiltration in the eye with post-laser in situ keratomileusis (LASIK) corneal inflammation. Serial OCT images are taken in a patient with post-LASIK inflammation and are used to see the response to treatment over a time period. Clinical value of FD-OCT as a diagnostic tool in objective assessment of corneal inflammation and response to treatment is shown.     

Clinical efficacy of amniotic membrane transplantation in the treatment of various ocular surface diseases.

PURPOSE: To investigate the efficacy of permanent amniotic membrane transplantation (AMT) for the treatment of various ocular surface diseases. METHODS: The medical records of 62 eyes from 58 patients who had undergone permanent AMT were reviewed. The amniotic patches were grafted for the treatment of neurotrophic ulcers (n=15), inflammatory corneal ulcers (n=15), scleral ulcers (n=11), painful bullous keratopathy (n=8) and pterygium as an adjuvant to a conjunctival autograft (n=13). Cryo-preserved or freeze-dried amniotic membrane (AM) were used. The overall success rate, the interval to epithelialization, pain-subsiding time, and complications were evaluated. The pain relief and the full epithelialization interval in the bullous keratopathy patients given the cryo-preserved AM were compared with those given the freeze-dried AM. RESULTS: The success rate in the patients with neurotrophic ulcer, inflammatory corneal ulcer, scleral ulcer and bullous keratopathy were 93.3%, 66.7%, 92.9% and 100%, respectively. A conjunctival autograft with AMT showed a 100% success rate without recurrence. The time to re-epithelialization was 24.4+/-24.2, 20.4+/-5.8, and 16.9+/-7.0 days in patients with neurotrophic, inflammatory and scleral ulcers, respectively (p=0.431). The pain relief interval in the cryo-preserved and freeze-dried AM group was 17.7 and 23.3 days, and the re-epithelialization interval was 29 and 22 days, respectively, which was insignificant. CONCLUSIONS: AMT has a high success in the treatment of neurotrophic, scleral ulcer, bullous keratopathy and pterygium with a low rate of complications but presented only partial success in the treatment of inflammatory corneal ulcers. The clinical efficacy of AMT was not related to the methods used to preserve the AM.