PTK在再次准分子激光角膜切削术中的应用

目的 探讨用PTK技术矫治因PRK术后出现的严重不规则角膜散光并欠矫的方法,观察其疗效。方法 参考角膜地形图,先使用阻滞剂粘弹剂保护角膜凹面再行PTK术,得到光滑的角膜表面后,再次准分子激光角膜切削术。结果 3例5眼均获得良好的疗效,术后裸眼视力1.0,角膜透明。随访2年疗效巩固,手术前后的角膜地形图可以证明。结论 采用PTK技术治疗因PRK术出现的不规则散光是有效的。     

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.     

准分子激光屈光性角膜切削术治疗高度近视探讨

目的探讨准分子激光角膜切削术(PRK)治疗高度近视的效果.方法应用VISX20/20B型准分子激光仪,采用多光区切削法治疗-15D以上超高度近视.术后随访19～38月,并对结果进行分析.结果术前最佳矫正视力0.69±0.19,术后裸眼视力0.61±0.11.术后3月左右角膜上皮下混浊(haze)明显,1年后最轻,该组haze平均(0.53±0.17)级,屈光度回退平均(3.15±1.56)D.结论对于角膜较薄,不适于准分子激光原位角膜磨削术(LASIK)的超高度近视患者,PRK的多光区切削方式仍不失为一种安全、有效且稳定性较好的方法.     

Mitomycin C application after photorefractive keratectomy in high,moderate, or low myopia: Systematic review and meta-analysis

Photorefractive keratectomy (PRK) is considered a safe approach laser procedure with a clinical significance in correcting myopia results. PRK requires removing the whole superficial epithelium. The integrity of the epithelial basement membrane and the deposition of abnormal extracellular matrix can put the cornea in a probable situation for corneal haze formation. Mitomycin C (MMC) is applied after excimer laser ablation as a primary modulator for wound healing, limiting corneal haze formation. We aim to summarize the outcomes of MMC application after laser ablation. We searched Scopus, PubMed, Cochrane CENTRAL, and Web of Science till December 2020 using relevant keywords. The data were extracted and pooled as mean difference (MD) or risk ratio (RR) with a 95% confidence interval (CI), using Review Manager software (version 5.4). Our analysis demonstrated a statistically significant result for MMC application over the control group in terms of corneal haze formation postoperatively (RR = 0.29, 95% CI: [0.19, 0.45], P < 0.00001). Regarding corrected distance visual acuity (CDVA), no significant difference was observed between the MMC group and the control group (MD = 0.02; 95% CI: [-0.04, 0.07]; P = 0.56). Regarding the uncorrected distance visual acuity (UDVA), the analysis favored the MMC application with (MD -0.03, 95% CI: [-0.06, -0.00]; P = 0.05). There was no statistically significant increase in complications with MMC. In conclusion, MMC application after PRK is associated with a lower incidence of corneal haze formation with no statistically significant side effects. The long term effect can show improvement regarding UDVA favoring MMC. However, there is no significant effect of MMCs application regarding CDVA, and SE.     

飞秒激光小切口角膜基质透镜取出术与经上皮准分子激光角膜切削术矫治中低度近视术后患者功能性光学区的对比研究

目的　探讨飞秒激光小切口角膜基质透镜取出术（small incision lenticule extraction，SMILE）与经上皮准分子激光角膜切削术（transepithelial photorefractive keratectomy，TransPRK）矫治近视术后功能性光学区的大小并分析可能的影响因素。方法　收集2017年11月至2018年2月在我院接受角膜屈光手术的近视及近视散光患者102 例，均纳入右眼进行分析。其中SMILE组62例62眼，TransPRK组40例40眼，分别于术前及术后3个月应用Pentacam三维眼前节分析系统测量功能性光学区的大小，对比分析两组术后功能性光学区的变化特点及可能的影响因素。结果　SMILE组及TransPRK组术前功能性光学区分别为（7.18±1.00）mm和（7.33±0.81）mm，术后3个月两组分别为（6.00±0.78）mm及（5.77±0.82）mm，与术前相比均显著缩小（均为P=0.000），其中SMILE组较术前缩小（1.18±1.00）mm，TransPRK组缩小（1.56±1.02）mm。SMILE组术后功能性光学区较TransPRK组大，差异有统计学意义（P=0.038）。两组术后功能性光学区的缩小与术前等效球镜度数均呈显著负相关（均为P＜0.05），与角膜曲率变化量、球差变化量及Q值变化量均呈显著正相关（均为P＜0.01）。结论　SMILE与TransPRK术后功能性光学区均显著缩小，在相同手术光学区设计的情况下，SMILE较TransPRK术后获得了更大的功能性光学区。     

Visual outcome of excimer laser photorefractive keratectomy for myopia: A comparison of three laser delivery systems in Australia

Purpose: To compare the performance of the three excimer laser delivery systems in correcting myopia. Methods: The first generation ercimer laser systems produced by Summit, VEX and LEI were examined. The first 40 consecutive eyes with six-month refractive results were selected from the LEI centre. Forty consecutive eyes, matched for age and attempted corrections, were then selected from each of the Summit and VEX centres, The postoperative visual results were examined retrospectively and compared among the three groups. Results: At six-month follow-up, the mean and standard deviation of the spherical equivalent refraction were +0.27 (SD, 0.65) dioptre in the Summit group, -0.33 (SD, 0.83) dioptre in the VISX group and -0.62 (SD, 0.89) dioptre in the LEI group (P= 0.0001, ANOVA). Thirty-five eyes (88%) in the Summit group, 33 eyes (83%) in the VISX group and 28 eyes (70%) in the LEI group achieved corrections within 1 dioptre of intended corrections (P = 0.131, χ² test). Four eyes (10%) in the Summit group, two eyes (5%) in the VISX group and one eye (3%) in the LEI group were over-corrected by more than 1 dioptre at six-month follow-up. Unaided visual acuity (Snellen equivalent) was 6/12 or better in 37 eyes (93%) in the Summit group, 34 eyes (85%) in the VISX group and 34 eyes (87%) in the LEI group (data missing in one eye). Loss of one or more lines of best corrected visual acuity (Snellen equivalent) was found in 6 of 39 eyes (15%) in the Summit group, 10 of 40 eyes (25%) in the VISX group and 4 of 36 eyes (11%) in the LEI group (P= 0.258, χ² test). Regression between one and six month follow-up differed significantly (P= 0.001, ANOVA) among the groups, with the mean of -1.25 (SD, 0.94) dioptres in the Summit group, -0.59 (SD, 1.01) dioptre in the VISX group and -0.40 (SD, 0.99) dioptre in the LEI group. Conclusions: Statistically comparable results were found in the three groups in terms of refraction and visual acuity six months after myopic photorefractive keratectomy. No statistical differences were found between the groups in terms of significant overcorrection or loss of best corrected acuity. The group treated using the Summit system demonstrated significantly greater regression than the other groups, necessitating larger initial hyperopic shifts.     

羊膜移植对激光角膜光学切除术后haze形成的影响

目的 探讨羊膜移植对激光角膜光学切除术（photorefractive keratectomy,PRK)后上皮下混浊（haze)的影响。方法 对18只新西兰白兔双眼行PRK,术后一眼立即行角膜表面羊膜移植术,另眼作为对照。术后4周和8周用裂隙灯检查角膜haze形成情况。将兔于术后1、4、8周处死,取下角膜进行常规组织切片,分别进行HE染色、AgNOR染色和胶原染色检查。结果 术后4周和8周,羊膜移植组haze轻于对照组。术后1、4、8周,羊膜移植组切削区中央上皮层厚度明显小于对照组（P＜0．05）,切削区边缘上皮层厚度两组间无显著差异（P＞0．05）;术后4周和8周,羊膜移植组术区前基质角膜细胞数较对照组少（P＜0．05）,且增殖活性较对照组低,Ⅲ型胶原形成少。结论 羊膜移植能抑制RK后基质角膜细胞增殖和Ⅲ型胶原形成而有效的减轻haze的形成。     

准分子激光屈光性角膜切削术治疗近视眼的远期效果分析

目的：评价准分子激光屈光性角膜切削术（ＰＲＫ）治疗不同程度近视眼的远期疗效。方法：应用ＶＩＳＸ２０／２０型准分子激光机对２５８只不同程度的近视眼进行ＰＲＫ治疗,对３～５年随 是行统计分析,按术前近视度分两组,Ａ组－１．００～－６．００Ｄ（等球镜,下同）１１６只眼,Ｂ组－６．２５～－１２．００Ｄ１４２只眼。结果：经ＰＲＫ治疗后,Ａ组裸眼视力≥１．０占８６．２％,≥０．５占９７．４％,剩余屈光度为（－