角膜基质透镜在角膜溃疡或穿孔修复中的应用

目的：研究由全飞秒激光SMILE手术所得的角膜基质透镜作为角膜移植材料治疗角膜溃疡的临床疗效。

方法：回顾性病例研究。收集本院2017-01/06角膜溃疡患者6例6眼,其中细菌性、真菌性、深层异物伴感染各1例1眼,角膜穿孔3例3眼。采用由全飞秒激光SMILE手术所得的角膜基质透镜作为角膜移植的材料进行修复手术,确保植片与角膜层间无空气间隙。术后随访1～6(平均3.71±1.56)mo,观察手术前后视力、角膜移植物存活情况及术后并发症发生情况等。

结果：所有患者均在控制感染下顺利完成手术,无术中并发症。术后所有角膜植片透明。末次随访时,患者最佳矫正视力(best corrected visual acuity,BCVA)较术前明显改善(0.48±0.12 vs 1.50±0.08),差异具有统计学意义(P<0.01)。

结论：来源于全飞秒激光屈光手术的角膜基质透镜用于角膜溃疡修复是安全有效的,但植片的远期疗效尚需进一步观察。     

Alcohol delamination of the corneal epithelium for recurrent corneal erosion syndrome

AIM: To evaluate the outcomes of alcohol delamination (ALD) of the corneal epithelium for the treatment of recurrent corneal erosion syndrome (RCES) and to implement a standardized treatment protocol for this condition utilizing evidence based practice and the findings of an internal audit. METHODS: A retrospective analysis of 42 eyes of 40 patients diagnosed with RCES who were treated with ALD between January 2006 and March 2016 was conducted. Patients had 20% alcohol applied to the cornea with the use of a well for 40s. Patients were reviewed one week later in the Outpatient Department. Outcome criteria were established based on standards from other studies in the medical literature. These included, a treatment success rate of at least 72% (defined as complete resolution of symptoms one month after treatment), a postoperative complication a rate of <5% (mainly infective keratitis, and subepithelial haze), and the absence of any detrimental effect on visual acuity in ≥95% of patients. RESULTS: The mean age at the time of ALD was 41.17±13.44y. Patients were followed for an average of 12.8±15.65mo. The majority were female (52.5%, n=21) and the majority of eyes treated with ALD were left eyes (62.9%, n=26). Trauma was the primary aetiology in our study population. Treatment was successful in 73.8% (n=31) of eyes and in 75% (n=30) of patients. Recurrence occurred in 26.2% of eyes at a mean of 10.41±12.63mo post treatment. CONCLUSION: ALD is an efficacious and cost-effective primary surgical intervention for RCES.     

角膜切口对白内障手术后散光的影响

目的:观察沿角膜散光陡峭轴方向做透明角膜切口行白内障超声乳化联合人工晶状体植入术后散光和视力的变化。方法:根据IOL-Master检测结果选择角膜最大屈光力轴行3.0mm透明角膜切口做白内障超声乳化术42眼作为观察组(A组),常规颞上(右眼)、鼻上(左眼)3.0mm透明角膜切口白内障超声乳化术68眼作为对照组(B组)。检测术前、术后1d;1wk;1,3mo角膜散光和视力变化。结果:A组术前、术后1d;1wk;1,3mo视力分别为0.2±0.24,0.73±0.37,0.78±0.38,0.94±0.36,0.76±0.13;B组为0.17±0.2,0.82±0.3,0.84±0.2,0.77±0.26,0.8±0.36;差异无统计学意义(P>0.05)。A组术前、术后1d;1wk;1,3mo角膜散光度分别为1.01±0.10D,1.33±0.13D,1.15±0.14D,0.90±0.13D,0.89±0.12D;B组为0.95±0.13D,1.25±0.15D,1.07±0.13D,0.87±0.12D,0.82±0.11D。术后1d;1wk;1mo与术前相比散光度均无统计学意义(P>0.05)。两组术后3mo散光度与术前相比差异有统计学意义(P<0.05)。两组术后3mo裸眼视力≥0.8者分别为21眼(50%)和32眼(47%),两者相比有统计学意义(P<0.05)。结论:沿陡轴透明角膜切口白内障超声乳化联合人工晶状体植入术有助于患者视力提高及减少术后角膜散光。     

Effects of corneal neovascularization on the manifestations of Avellino corneal dystrophy (granular corneal dystrophy type II)

PURPOSE: To evaluate the corneal deposits of Avellino corneal dystrophy (ACD) in patients with corneal neovascularization from pterygium or phthisis bulbi as a way of understanding the pathogenesis of ACD. METHODS: Five patients with ACD with pterygium, 10 patients with ACD (age >50 years) without pterygium, 1 patient with ACD with phthisis bulbi with corneal neovascularization, and 1 patient with ACD with phthisis bulbi without corneal neovascularization were examined. The corneal deposits of all patients were assessed by slit-lamp examination and reviewed with biomicroscopic photographs. The distance between the limbus and the nearest corneal opacities was measured. RESULTS: In eyes with vascularized nasal pterygia, there was a granule-free zone adjacent to the advancing edge of the pterygium so that the distance between the nasal limbus and the most nasally located granule exceeds that of the distance between the limbus and the closest granule elsewhere on the cornea. In patients with ACD with phthisis bulbi, no granular deposits were observed in the cornea with neovascularization, but there were deposits in the cornea without neovascularization. CONCLUSION: Corneal neovascularization prevents the deposition of corneal opacities in patients with ACD.     

近视眼角膜不同区域厚度差异及其与屈光度和曲率的关系

目的 探讨近视眼患者角膜不同区域厚度及其差异与屈光度、曲率之间的关系.方法 横断面研究.近视及近视散光患者264例(458眼),男122例,女142例.应用Pentacam眼前节测量分析系统对近视眼角膜厚度进行测量分析,选取角膜顶点、中央、最薄点;角膜厚度及角膜前表面切线曲率测量均取以角膜顶点为中心的2 mm、4 mm、6 mm、8 mm直径虚拟圆,以双眼颞侧水平设为0°,右眼顺时针、左眼逆时针递增记录可查位点的角膜厚度平均值及角膜切线曲率平均值.依据屈光状态不同分为低度近视组(屈光度≤-3.00 D)、中度近视组(-3.00 D＜屈光度≤-6.00 D)和高度近视组(-6.00 D ＜屈光度).多组间比较采用方差分析,左右眼比较应用独立样本t检验,不同位点角膜厚度相关性以及角膜厚度与其他因素相关性应用Pearson相关分析.结果 458眼角膜顶点、中央、最薄点厚度平均值分别为(529.58±22.38) μm、(529.75±22.51)μm、(527.78±22.71)μm.围绕角膜顶点的不同直径虚拟圆上角膜厚度最大平均值均位于90°位点,其平均值分别为(544.14±22.07) μm、(583.15±24.72) μm、(646.27±27.34) μm、(716.52±27.70)μm.围绕角膜顶点的2 mm、4 mm、6 mm、8 mm直径虚拟圆上角膜厚度最小平均值分别位于315°、315 °、337.5°、342°,其平均值分别为(532.48±23.51) μm、(549.24±26.97) μm、(590.02±27.06) μm、(657.37±32.03) μm.左右眼角膜中央、顶点和最薄点厚度呈正相关(r=0.768、0.548、0.671,P均＜0.05).低、中、高屈光度与角膜不同区域厚度的平均值均无相关性,低、中、高屈光度组角膜厚度与切线曲率均无相关性.结论 近视眼患者角膜不同直径虚拟圆范围内,上方角膜厚度最厚,颞侧及颞下方角膜厚度最薄.角膜厚度与屈光度和角膜前表面曲率均无相关性.     

Influence of corneal astigmatism, corneal curvature and meridional differences on corneal hysteresis and corneal resistance factor

Background: This study investigated the influence of corneal astigmatism, corneal curvature and meridional differences on corneal hysteresis (CH) and the corneal resistance factor (CRF) in a group of normal Chinese persons. Methods: Ninety‐five participants were recruited and data from the eye with higher corneal astigmatism were analysed. The anterior corneal curvature was measured by corneal topography. The Goldmann‐correlated intraocular pressure (IOPg), corneal‐compensated intraocular pressure (IOPcc), CH and CRF at different meridians (default horizontal position, 10°, 20° and 30° along the superotemporal and inferonasal meridians) were obtained from an ocular response analyser. The corneal powers at these specific meridians also were calculated. Results: At the default position, the IOPg and CRF had weak correlations with corneal astigmatism, while the IOPcc and CH were not significantly correlated with corneal astigmatism. Both the IOPg and IOPcc were measured significantly higher at the default position. The CH and CRF were lower at the default position but the difference in the CRF from obliquity could not reach statistical significance. The CH was not significantly correlated with the corneal power at all meridians. The CRF correlated with the corneal power only at 30° superotemporal. Conclusion: Corneal astigmatism and head tilt did not have much effect on the measurement of CH and the CRF, both of which were lowest along the horizontal meridian. Clinically, the difference was small. The influence of corneal power on CH and the CRF was minimal.     

Snailtracks of the corneal endothelium

An unusual pattern of corneal endothelial cell alterations has been observed at the slitlamp in eyes following intraocular surgery. Because of their appearance, we have called these changes "snailtracks". We have commonly seen these snailtracks following extracapsular cataract extraction. Similar changes have been noted in cadaver corneas stored in McCarey-Kaufman (M-K) medium. This study presents information which suggests that these changes represent corneal endothelial cell damage.     

Injuries of the corneal endothelium

Examples of "endogenous" or direct and "endogenous" or indirect endothelial trauma are presented. Corneal contusion, McCannel suture, YAG laser iridectomy, congenital luxation of the lens, and chronic over wearing of contact lenses all cause traumatic changes. The etiology and effects of these changes are discussed. Specular microscopy of the corneal endothelium permits good clinical control of both the trauma and wound healing.     

Characterization of the aspheric corneal surface with intrastromal corneal ring segments.

PURPOSE: Anterior corneal surface asphericity was examined in eyes of Phase II clinical trial participants, before and after intrastromal corneal ring segments (ICRS, Intacs) refractive surgery, and surveyed for relationship to clinical visual performance. METHODS: Aspheric test objects with surface asphericity (Q) ranging from -0.01 Q to -1.44 Q and base radius of curvatures ranging from 7.5 mm to 9.0 mm were measured topographically using videokeratography. Radius of curvature asphericity profile plots were produced for test objects and compared to similar plots created for trial participant eyes (n=25) to quantify corneal asphericity. The potential effects of different amounts of corneal asphericity were assessed using measurement of uncorrected and spectacle-corrected visual acuity and photopic contrast sensitivity. RESULTS: Preoperative corneal asphericity ranged from -0.01 Q to -0.81 Q and postoperative from -0.01 Q to -1.44 Q. Preoperative uncorrected visual acuity was significantly related to corneal asphericity; more myopic eyes tended to have more prolate corneal asphericity. Corneal asphericity was not significantly related to spectacle-corrected visual acuity or photopic contrast sensitivity, before or after surgery. CONCLUSION: Postoperative corneal asphericity values demonstrated that intrastromal corneal ring segments (Intacs) produced a prolate aspheric surface for myopic correction from -1.00 D to -6.00 D. This study indicated that the range of corneal asphericity measured in these 25 eyes, before and after surgery, provided good visual acuity and normal contrast sensitivity.     

Outcomes of corneal transplantation: a corneal surgeon vs the general ophthalmologist

AIMS: The aim of this study was to examine the outcomes of corneal transplantation in cases performed by a group of general ophthalmologists and those performed by an ophthalmologist with a subspecialist interest in corneal surgery. METHODS: A retrospective analysis of the outcomes in corneal transplantation was carried out for a 4-year period in three separate units in South Wales. In addition to patient demographic details, the primary diagnosis, type of keratoplasty performed, and outcome of surgery were noted. The data were analysed statistically by the Mann-Whitney U-test (one-tailed). RESULTS: Group A (n=35) was defined as those patients whose surgery was performed by a general ophthalmologist. There were seven surgeons in this group with a mean of five procedures each over the study period. Group B (n=54) were all operated on by the same surgeon. The mean age in both groups was similar with group A comprising of 66% males with 50% males in group B. The commonest indication for surgery in both groups was endothelial cell failure In group A, graft clarity at 1 year was 83% for all aetiologies and 73% at 2 years. In group B, the results were 97 and 92%, respectively. In group A, overall 56% achieved 6/18 or better compared with 68% in group B. In group A 73% had an improvement of one or more lines compared with 84% in group B (P=0.085). Reasons for graft failure in both groups were similar. CONCLUSION: The success rate of corneal transplantation carried out by general ophthalmologists in this study is reduced when compared with cases performed by a corneal surgeon. The explanation for this is not clear, but is undoubtedly multifactorial.     

Orbscan测量近视眼角膜厚度

目的评价裂隙扫描角膜地形图/角膜测厚系统(Orbscan corneal topography system)在分析近视眼角膜厚度分布特征中的应用价值.方法应用Orbscan(Orbtek,Salt Lake     

Refracting the corneal graft

Patients who have undergone penetrating keratoplasty have unique postoperative refractive requirements. These include irregular astigmatism, high corneal toricity, and anisometropia. We present a stepwise clinical approach for accurate, efficient refraction of these patients, utilizing visual acuity measurement, retinoscopy, subjective refraction, keratometry, photokeratoscopy, and diagnostic rigid contact lens application.