5-year follow-up of combined non-topography guided photorefractive keratectomy and corneal collagen cross linking for keratoconus

AIM: To evaluate the visual outcomes of simultaneous non-topography guided photorefractive keratectomy (PRK) and corneal collagen cross-linking (CXL) in eyes with keratoconus 5y after the procedure. METHODS: Prospective, interventional, non-randomized, and non-controlled case series design was used. Sixty eyes of 30 patients (16 males and 14 females; age: 21-41y) with mild, non-progressive (stages 1-2) keratoconus were enrolled. Refraction, uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) , flat and steep keratometry readings, and adverse events were evaluated preoperatively and postoperatively. Data were collected preoperatively and postoperatively at 3mo, 1, 2, 3, 4, and 5y follow-up visits after combined non-topography-guided PRK with CXL was performed. All patients had at least 5y of follow-up. RESULTS: All study parameters showed a statistically significant improvement at 5y over baseline values. The mean follow-up time was 68.20±4.71mo (range: 60-106mo). Patients showed a significant improvement in UDVA from 1.24±0.79 logMAR prior to combined non-TG-PRK+CXL to 0.06±0.15 logMAR postoperatively at the time of their last follow-up visit. CDVA significantly increased from 0.06±0.19 logMAR preoperatively to 0.03±0.12 logMAR postoperatively. A significant decrease in the mean spherical equivalent (SE) refraction was observed from -2.28±1.8 to -0.79±0.93 diopters (D) (P<0.05), and the manifest sphere decreased from -1.62±1.23 to -0.27±0.21 D (P=0.001). The manifest cylinder significantly decreased from -1.73±0.86 to -0.29±0.34 D postoperatively (P=0.001). The mean steep keratometry was 45.13±1.32 vs 47.28±2.12 D preoperatively (P<0.05), and the preoperative mean steepest keratometry (Kmax) 48.6±3.1 was reduced significantly to 46.8±2.9 postoperatively (P<0.05). CONCLUSION: Combined non-TG-PRK with 15min CXL is an effective and safe option for correcting mild refractive error and improving visual acuity in patients with mild stable keratoconus.     

快速角膜胶原交联治疗进展期圆锥角膜的临床研究

目的:探讨紫外光照射仪快速跨上皮胶原交联治疗进展期圆锥角膜的临床效果.方法:收集2014-12/2017-02在我院确诊为进展期圆锥角膜患者52例102眼的临床资料(角膜最大曲率值Kmax<60.0D,角膜厚度≥400μm),进行回顾性分析和随访,所有患者手术前后常规行裸眼和最佳矫正视力、眼压、裂隙灯显微镜、角膜地形图、光学相干断层扫描(optical coherence tomography,OCT)、角膜内皮镜、眼前节彩照等检查.结果:原发性圆锥角膜患者52例102眼中,男36例70眼,女16例32眼,平均年龄19.5±4.6岁.所有患者术前最佳矫正视力(LogMAR视力表)平均为0.84±0.89,术后最佳矫正视力平均为0.69±0.72,两者比较差异无统计学意义(P=0.398).所有患者术前裸眼视力(LogMAR视力表)平均为1.02±0.62,术后裸眼视力平均为0.85±0.59,两者比较差异无统计学意义(P=0.154).所有患者术前眼压平均为12.95±4.40mmHg,术后眼压平均为11.92±3.66mmHg,两者比较差异无统计学意义(P=0.272).角膜内皮镜检查结果提示,手术前后内皮细胞密度和形态无改变(P=0.552).角膜地形图检查结果提示,所有患者术后Kmax平均值为50.83±3.48D,较术前Kmax(平均值为52.05±3.63 D)降低,且两者比较差异有统计学意义(P=0.017),所有患者术后角膜平均曲率值(AveK)为47.74±2.51D,较术前AveK平均值(48.73±4.33D)降低,且两者比较差异有统计学意义(P=0.041).术后所有患者采用前节OCT随访角膜胶原交联深度,平均交联深度位于192±23.6μm.角膜厚度值术后与术前比较,差异无统计学意义(P=0.816),无1例患者术后出现严重的手术相关并发症.结论:快速角膜胶原交联治疗进展期圆锥角膜患者术后角膜K值有下降的趋势,且随访期间情况稳定.同时对角膜内皮和眼内结构没有损伤,无严重手术相关并发症,该治疗方法是一种性价比较高的治疗方式.     

去上皮快速角膜胶原交联术治疗进展期圆锥角膜

目的：研究去上皮快速角膜胶原交联术(CXL)治疗进展期圆锥角膜的疗效。

方法：回顾性研究。收集2020-04/2021-12就诊于宁夏回族自治区人民医院 宁夏眼科医院行去上皮快速CXL的进展期圆锥角膜患者32例43眼。于术前及术后1、3、6mo行裂隙灯、眼压、裸眼视力、矫正视力、角膜内皮镜、眼前节分析仪Pentacam和可视化角膜生物力学Corvis ST检查,记录手术前后角膜情况、裸眼视力(UCVA)、最佳矫正视力(BCVA)、角膜内皮数、角膜最大曲率(Kmax)、角膜厚度最薄点(TCT)、前后表面K1、K2值、矫正眼内压(bIOP)、第一次压平时间(A1T)、第一次压平长度(A1L)、第一次压平速度(A1V)、第二次压平时间(A2T)、第二次压平长度(A2L)、第二次压平速度(A2V))、最大形变幅度(HCDA)、最大形变曲率半径(HCR)、最大压陷时两峰间距(HCPD)、第1次压平时角膜硬度(SP-A1))值。

结果：术前、术后6mo UCVA(LogMAR)(1.06±0.49、0.78±0.39)和BCVA(LogMAR)(0.48±0.34、0.38±0.29)比较均有差异(P<0.05),角膜内皮细胞比较无差异(2917.39±288.38 vs 2959.19±336.27cells/mm²,P=0.477)。手术前后Kmax、TCT、前表面K1、K2值、后表面K1值比较均有差异(P<0.05),且均在术后1mo升高,术后3mo后恢复至术前水平,而后表面K2值比较无差异。手术前后A1T、HCPD、SP-A1比较差异均有统计学意义(P<0.05),A1L、A1V、A2T、A2L、A2V、HCDA、HCR、bIOP比较无差异(P>0.05)

结论：去上皮快速CXL在术后6mo内能够阻止进展期圆锥角膜进展并且具有一定的安全性。     

圆锥角膜患者角膜光密度与形态及生物力学的相关性研究

目的:探讨圆锥角膜患者角膜光密度与角膜形态参数及生物力学特性的相关性。方法:回顾性病例研究。收集2020-01/12在郑州市第二人民医院就诊的原发性圆锥角膜患者48例70眼,使用Pentacam眼前段分析系统测量角膜形态,包括角膜前表面中央扁平子午线曲率(K1)、角膜前表面陡峭子午线曲率(K2)、角膜前表面中央平均曲率(Km)、角膜前表面最大曲率(Kmax)、角膜前表面高度(ACE)、角膜后表面高度(PCE)、最薄点角膜厚度(TCT),以及圆锥锥顶距角膜顶点的距离(DCA)。测量不同分区不同层次的角膜光密度。使用可视化角膜生物力学测量仪观察角膜形变过程并测量相关参数,包括第一次压平时间(AT1),第一次压平长度(AL1),第一次压平速度(V1),第二次压平时间(AT2),第二次压平长度(AL2),第二次压平速度(V2),最大压陷时间(HCT),最大压陷形变幅度(HCDA),最大压陷曲率半径(HCR),最大压陷峰距(HCPD),硬度参数(SPA1),水平方向Ambrósio相关厚度(ARTh)。结果:圆锥角膜患者距角膜顶点≤2mm前层光密度与K1、K2、Km、Kmax均呈正相关(r=0.291、0.315、0.315、0.387;P=0.015、0.008、0.008、0.001)。距角膜顶点≤2mm、>2mm且≤6mm前层及全层、>2mm且≤6mm后层光密度与ACE均呈正相关(r=0.465、0.302、0.317、0.291、0.335;P<0.01、P=0.011、0.008、0.014、0.005);上述各区域各层的光密度与PCE均呈正相关(r=0.565、0.369、0.348、0.306、0.284;P<0.01、P=0.002、0.003、0.010、0.017)。距角膜顶点≤2mm前、中、后及全层光密度,>2mm且≤6mm中、后及全层光密度均与AL1均呈负相关(r=-0.284、-0.290、-0.245、-0.326、-0.282、-0.395、-0.310;P=0.017、0.015、0.041、0.006、0.018、0.001、0.009)。距角膜顶点≤2mm中层光密度、>2mm且≤6mm中、后层光密度与AL2呈负相关(r=-0.246、-0.256、-0.256;P=0.041、0.032、0.032)。距角膜顶点≤2mm前层光密度与HCR呈负相关(r=-0.308,P=0.010)。距角膜顶点≤2mm中、后层光密度、>2mm且≤6mm中层光密度与HCT均呈负相关(r=-0.292、-0.340、-0.262;P=0.014、0.004、0.028)。距角膜顶点≤2mm前层及全层光密度、>2mm且≤6mm后层光密度与ARTh呈负相关(r=-0.430、-0.293、-0.319;P<0.01,P=0.014、0.007)。结论:圆锥角膜患者角膜光密度测定值与角膜形态和生物力学特性相关,可能成为圆锥角膜的潜在诊断指标。     

Topography versus non-topography-guided photorefractive keratectomy with corneal cross-linking variations in keratoconus

AIM: To compare the visual results of non-topography-guided and topography-guided photorefractive keratectomy (PRK) applying sequential and simultaneous corneal cross-linking (CXL) treatment for keratoconus. METHODS: Interventional and comparative prospective study. Sixty-nine eyes (36 patients) suffering from keratoconus (stages 1 Amsler-Krumeich classification) were divided into four groups: sequential topography-guided photorefractive keratectomy with CXL, simultaneous topography-guided photorefractive keratectomy with CXL, simultaneous non-topography guided photorefractive keratectomy with CXL, and sequential non-topography guided photorefractive keratectomy with CXL. The main outcome measures were pre- and postoperative uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (CDVA), manifest refraction, contrast sensitivity, and keratometry. RESULTS: All analyzed visual, contrast sensitivity, and refractive parameters showed a significant improvement in the four groups (all P<0.05). A noticeable improvement was seen in keratometry in all the groups, and a remarkable difference was observed between topography-guided groups in comparison to non-topography-guided groups (P<0.05). Interestingly, the improvement in all parameters showed a degree of stability to the end of the follow-up. CONCLUSION: The treatment priorities in all four groups are safety, efficacy, and predictability in the correction of the sphero-cylindrical errors in mild and moderate keratoconus. No significant differences among groups in the recorded objective outcomes were found.     

【In Press】 Five-year follow-up of combined non-topography guided photorefractive keratectomy and corneal collagen cross linking for keratoconus

AIM: To evaluate the visual outcomes of simultaneous non-topography guided photorefractive keratectomy (PRK) and corneal collagen cross-linking (CXL) in eyes with keratoconus 5 y after the procedure. METHODS: Prospective, interventional, non-randomized, and non-controlled case series design was used. Sixty eyes of 30 patients (16 males and 14 females; age: 21-41y) with mild, non-progressive (stages 1-2) keratoconus were enrolled. Refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, flat and steep keratometry (K) readings, and adverse events were evaluated preoperatively and postoperatively. Data were collected preoperatively and postoperatively at 3-months, 1-, 2-, 3-, 4-, and 5-year follow-up visits after combined non-topography-guided PRK with CXL was performed. All patients had at least 5y of follow-up. RESULTS: All study parameters showed a statistically significant improvement at 5y over baseline values. The mean follow-up time was 68.20±4.71mo (range: 60-106mo). Patients showed a significant improvement in UDVA from 1.24±0.00 logMAR prior to combined non-TG-PRK+CXL to 0.06±0.00 logMAR postoperatively at the time of their last follow-up visit. CDVA significantly increased from 0.06±0.00 logMAR preoperatively to 0.03±0.00 logMAR postoperatively. A significant decrease in the mean spherical equivalent (SE) refraction was observed from -2.28±1.8 to -0.79±0.93 diopters (D) (P<0.05), and the mean cylinder decreased from -1.628±0.76 (preoperative) to -0.25±0 (postoperative) (P=0.001). The mean keratometry was 45.13±0.00 vs 47.28±0.00 D preoperatively (P<0.05), and the manifest astigmatism significantly decreased from -1.63±0.76 to -0.25±0 (P=0.001). CONCLUSION: Combined non-topography-guided PRK with 15min is an effective and safe option for correcting mild refractive error and improving visual acuity in patients with mild stable keratoconus.     

Surgical management of uveitis-glaucoma-hyphema syndrome

AIM: To compare corneal demarcation line depth in both accelerated epithelium-off and trans-epithelium cross linking (CXL) using anterior segment optical coherence tomography (AS-OCT) and its relation to maximum keratometry (Kmax) progression in both techniques.METHODS: A prospective comparative interventional study where patients with mild to moderate keratoconus (KC) were classified into two groups: accelerated epithelium-off and trans-epithelium CXL based on corneal pachymetry. Assessment of corneal demarcation line (DL) depth was carried out after 3mo by AS-OCT. Kmax readings were evaluated after one year follow up using the Scheimpflug imaging system. RESULTS: Study included 74 eyes of 44 patients. Group A underwent epithelium-off CXL (41 eyes), while Group B underwent trans-epithelium CXL (33 eyes). At 3mo follow up, mean corneal DL depth in Group A was 219.9±58.4 µm while in Group B was 127.2±7.8 µm (P<0.05). The mean Kmax changed from 51.9±3.9 to 51.3±4.2 diopters in Group A and from 53.1±4.1 to 53.6±5 diopters in Group B with insignificant difference in Kmax changes in either group (P>0.05). In addition, no significant change in corneal pachymetry was found in both groups (mean change at 1y: 6.4±4.7 and -10.1±2.3 µm in Group A and B respectively).CONCLUSION: Despite a significantly deeper corneal DL depth created by accelerated epithelium-off CXL technique compared to accelerated trans-epithelium CXL, there is no significant impact on keratoconus progression.     

Endoscopic transnasal canaliculorhinostomy for refractory common canalicular obstruction with an unidentifiable lacrimal sac

AIM: To compare the safety and efficacy of conventional versus accelerated (9 mW/cm2) CXL in progressive keratoconus at the 2-year follow-up. METHODS: In this prospective study, consecutive progressive keratoconus patients were randomized to receive either conventional CXL (CCXL) or accelerated CXL (ACXL, using hydroxypropyl methylcellulose-assisted riboflavin imbibition for 10min) at 9 mW/cm2. Visual, refractive, keratometric, topographic, and aberrometric outcomes and stromal demarcation line depth (DLD) measurements were compared at the end of a 2-year follow-up. RESULTS: Thirty-two eyes from 32 patients in the CCXL and 27 eyes from 27 patients in the ACXL groups completed 2-year follow-ups. At 2 years post-CXL, both uncorrected and corrected visual acuities improved significantly in both groups. The improvements in keratometric readings, flattening rate (flattening of the Kmax more than 1D), 3 topographic indices, and vertical coma were significantly better in the CCXL group compared to the ACXL group (P<0.05). The DLD as measured by anterior segment optical coherence tomography or in vivo confocal microscopy was better detectable and significantly deeper in the CCXL group compared to the ACXL group. The deeper DLD was found to be significantly correlated with improvements in the mean keratometry measurements. Progression was noted in 11.1% of eyes in the ACXL group, whereas progression was not observed in any patient eye in the CCXL group. CONCLUSION: In this prospective randomized study, ACXL was less effective in halting the progression of keratoconus at a 2-year follow-up compared to CCXL.     

圆锥角膜快速跨上皮交联手术前后Corvis ST参数的重复性及差异性

目的:评估圆锥角膜快速跨上皮交联手术前以及术后1mo Corvis ST参数的重复性及差异性。方法:研究纳入了30例30眼圆锥角膜患者进行分析。圆锥角膜患者术前和术后1mo分别进行三次Corvis ST重复测量。采用组内相关系数(ICC)、克伦巴赫alpha系数(Cronbach'α)、可重复性系数(RC)和变异系数(CV)评估Corvis ST参数的可重复性。采用配对t检验或Wilcoxon秩和检验评估术前与术后Corvis ST参数的差异。结果:术前39个Corvis ST参数中,26个(66.67%)参数重复性较好,6个(15.38%)参数重复性中等,7个(17.95%)参数的重复性较差。交联术后1mo,34个(87.18%)参数的重复性较好,3个(7.69%)参数重复性中等,2个(5.13%)参数的重复性较差。与术前相比,交联术后1mo圆锥角膜患者的眼压、生物力学校正眼压、第一次压平时间、曲率半径、第一次压平时的形变幅度、最大压陷偏离长度、角膜硬度参数值增加;而陡峭曲率、平坦曲率、平均曲率、第二次压平时间、2 mm最大形变幅度比值和综合半径值降低(均P<0.05)。结论:交联手术前和术后1mo Corvis ST参数均具有较好的可重复性,术后1mo圆锥角膜患者的角膜硬度较术前增加。     

微创超声乳化手术前后角膜前后表面及不同区域范围角膜参数的变化

目的：比较白内障微创超声乳化手术前后角膜前表面屈光力(ASF)、角膜真实净屈光力(TNP)和总角膜屈光力(TCRP)分布特点及角膜前后表面曲率半径比(B/F ratio)差异。

方法：前瞻性研究。收集2020-12/2021-05就诊于潍坊眼科医院行2.2mm微切口超声乳化白内障吸除联合人工晶状体植入术的年龄相关性白内障患者156例156眼。术前及术后3mo行Pentacam眼前节生物测量仪检查，收集以角膜顶点和以瞳孔为中心2、4、6mm环上和区域内ASF、TNP和TCRP，以及手术前后B/F ratio。

结果：术后3mo，以角膜顶点为中心2mm直径环上和区域内ASF值较术前均无差异(均P>0.05)，而4、6mm直径环上和区域内ASF值较术前均有差异(均P<0.05)； 以瞳孔为中心2mm直径环上及区域内ASF值较术前均无差异(均P>0.05)。以角膜顶点为中心和以瞳孔为中心2、4、6mm直径环上和区域内TNP、TCRP值较术前均有差异(均P<0.05)。术前以角膜顶点为中心和瞳孔为中心在2mm与6mm之间环上和4mm与6mm之间环上TCRP值均有差异(均P<0.0167)； 在2mm与6mm区域内TCRP值均有差异(均P<0.0167)； 术后3mo，以角膜顶点为中心和瞳孔为中心环上TCRP值在2mm与6mm之间、4mm与6mm之间均有差异(均P<0.0167)，而以角膜顶点为中心和瞳孔为中心区域内TCRP值仅在2mm与6mm直径范围内有差异(P<0.0167)。B/F ratio术前为81.79%±1.87%，术后3mo为80.68%±2.23%(P<0.001)。

结论：白内障手术前后以角膜顶点和以瞳孔为中心的不同直径环上及区域内各项角膜屈光力参数会有一定的变化和差异，人工晶状体度数计算的K值选择及基于角膜特性的人工晶状体个体化选择时应予以考虑。     

Comparison of total corneal power measurements obtained with different devices after myopic keratorefractive surgery

AIM: To analyze the differences, agreements, and correlation among total corneal power parameters generated by different instruments after myopic keratorefractive surgery. METHODS: The prospective cross-sectional study included patients who underwent myopic keratorefractive surgery and received measurements of corneal power 3mo after surgery. Automated keratometer was used for the measurement of simulated keratometry (SimK), swept-source optical coherence tomography (SS-OCT) based biometer for total keratometry (TK), anterior segment-OCT for real keratometry (RK), and Scheimpflug keratometer for the true net power (TNP), the total corneal refractive power (TCRP) and equivalent K-readings (EKR). The differences among these parameters were analyzed, and the agreements and correlation between SimK and other total corneal power parameters were investigated. RESULTS: A total of 70 eyes of 70 patients after myopic keratorefractive surgery were included. The evaluated corneal power parameters were as follows: SimK 38.32±1.93 D, TK 37.54±2.12 D, RK 36.64±2.09 D, TNP 36.56±1.97 D, TCRP 36.70±2.01 D, and EKR 37.55±2.00 D. Pairwise comparison showed that there were significant differences (P<0.001) among all parameters except for between TK and EKR, RK and TNP, RK and TCRP (P=1.000, 1.000, 1.000, respectively). The limits of agreement between SimK and TK, RK, TNP, TCPR, and EKR were 1.08, 1.08, 1.43, 1.48, and 1.73 D, respectively. All parameters showed good correlation with SimK, and the correlation coefficients were 0.995, 0.994, 0.983, 0.982, and 0.975. CONCLUSION: Among the corneal power parameters after myopic keratorefractive surgery, the value of SimK is the largest, followed by TK and EKR, with TCRP, RK, and TNP being the smallest. The differences among the parameters may be attributable to the different calculation principles. Correct understanding and evaluation of corneal power parameters can provide a theoretical basis for taking advantage of the total corneal power to improve the accuracy of intraocular lens calculation after keratorefractive surgery.     

Comparative 2-year outcomes of conventional and accelerated corneal collagen crosslinking in progressive keratoconus

AIM: To evaluate the value of parameters on CT scan in predicting dysthyroid optic neuropathy (DON) and to provide guidance for early diagnosis of DON accordingly. METHODS: A total of 67 eyes of 35 patients with thyroid-associated ophthalmopathy (TAO) were included in this study. Patients were divided into 2 groups (DON group and non-DON group). Parameters were measured on high resolution CT, including muscle index (MI), superior ophthalmic vein (SOV) dilatation, extraocular muscle volume/orbit volume (MV/OV), and intracranial fat prolapsed, and be compared between these 2 groups. The relation between those parameters and visual function [visual acuity (VA) and visual field defect (VF defect)] were also evaluated. RESULTS: MI and MV/OV were significantly higher in DON group (P=0.00035 and P=0.00026). No significant difference was detected regarding intracranial fat prolapse existence and SOV dilatation (P=0.36899 and P=0.14594). MV/OV was found to have significant negative correlation with both VF defect (P=0.02730) and VA (P=0.0000) while MI was found to have weak negative linear correlation with VA only (P=0.00017). The area under receiver operating characteristic curves was 0.82 for MV/OV and 0.75 for MI. The best performance in detecting DON was achieved when MV/OV is set at 0.20 with 72% sensitivity and 87% specificity and MI is set at 0.52 with 64% sensitivity and 80% specificity. CONCLUSION: MI and MV/OV are predictive parameters for DON. Together with clinical manifestations, MV/OV≥0.2 can be used as a good indicator for DON in TAO patients.     

核黄素/紫外线A诱导的角膜交联术治疗 薄角膜圆锥角膜术后3年疗效

目的：评估核黄素/紫外线A胶原角膜交联术（CXL）治疗薄角膜圆锥角膜患者术后的长期疗效。方法： 前瞻性研究。收集2015年1-7月因圆锥角膜于山东大学附属省立医院眼科行CXL治疗的患者19例（32 眼），其中男12例（21眼），女7例（11眼）。以角膜基质厚度400 µm为分界线，将圆锥角膜患者分为薄 角膜组和厚角膜组。薄角膜组使用低渗性核黄素溶液进行角膜交联术治疗，厚角膜组使用等渗核 黄素溶液进行CXL治疗，术后随访3年，观察角膜最大K（Kmax）值、裸眼视力（UCVA）、最佳矫正 视力（BCVA）、最薄处角膜厚度（TCT）、眼压及角膜内皮细胞计数（ECD）等参数变化。采用重复测 量方差分析、t检验、Wilcoxon符号秩和检验、Mann-Whitney U检验进行数据处理。结果：薄、厚角 膜组术后Kmax值随时间延长均持续降低（F=24.364，P<0.001；F=10.427，P=0.001）；薄角膜组术前， 术后1、2、3年Kmax值分别为（60.51±6.11）D、（57.43±6.82）D、（56.13±6.85）D、（54.97±6.66）D， 术后各时间点与术前相比差异均有统计学意义（t=3.670，P=0.002；t=4.637，P<0.001；t=5.816，P< 0.001）；厚角膜组术前，术后1、2、3年Kmax值分别为（54.56±6.27）D、（53.25±6.42）D、（52.32± 6.47）D、（51.58±6.70）D，术后各时间点与术前相比差异均有统计学意义（t=2.266，P=0.040； t=3.302，P=0.005；t=3.769，P=0.002）；术前薄角膜组Kmax值高于厚角膜组（t=2.714，P=0.011），术 后1、2、3年2组间Kmax值差异无统计学意义。术后3年，薄角膜组UCVA、BCVA、TCT与术前 相比差异有统计学意义（Z=-2.716，P=0.007；Z=-3.063，P=0.002；t=4.468，P<0.001），厚角膜组 UCVA、BCVA、TCT与术前相比差异有统计学意义（t=3.572，P=0.003；Z=-2.956，P=0.003；Z= -3.410，P=0.001）。2组眼压、ECD与术前相比差异均无统计学意义。薄、厚角膜组术前组间及术后 3年组间UCVA、BCVA、眼压、ECD比较差异均无统计学意义；术前、术后3年组间TCT差异有统计 学意义（Z=-4.816，P=0.001；Z=-4.024，P<0.001）。结论：CXL可以安全有效地控制薄角膜圆锥角膜 患者病情进展，提高视力。     

离子导入辅助角膜交联治疗青少年圆锥角膜

目的：评估离子导入辅助的跨上皮角膜交联治疗青少年圆锥角膜的安全性和有效性。方法：搜集12例(年龄12~18岁,平均15.8±2.08岁)进展期圆锥角膜患者,共15眼,采用0.1%核黄素蒸馏水溶液,离子导入(1 mA电流)辅助跨上皮给药5min,紫外线A(370 nm,3 mW/cm2)照射30min。记录术前、术后3mo和1a的裸眼视力、最佳矫正视力、K1、K2、最大K值、平均K值、角膜散光度数、角膜内皮细胞密度、眼内压、最薄角膜厚度、角膜顶点厚度。角膜参数应用角膜地形图评估,角膜内皮细胞密度应用非接触角膜内皮镜检查。结果：角膜交联1a后,裸眼视力、最佳矫正视力、K1、K2、最大K值、平均K值、角膜散光度数、角膜内皮细胞密度和眼内压均无显著变化。最薄角膜厚度从468.08±33.40μm下降到447.46±40.20μm (t=4.379,P=0.001),差异有统计学意义。角膜顶点厚度从476.07±35.96μm下降到454.60±49.32μm(t=4.270,P=0.001),差异有统计学意义。结论：采用0.1%核黄素蒸馏水溶液的离子导入辅助的角膜交联治疗青少年圆锥角膜是安全、有效的,1 a内能够阻止病情恶化,但是长期效果有待于进一步观察。     

Factors affecting outcomes of corneal collagen crosslinking treatment

Purpose

To assess the effects of preoperative patient characteristics on clinical outcomes of corneal crosslinking (CXL) treatment in patients with progressive keratoconus.

Methods

This retrospective study comprised 96 eyes of 96 patients who had unilateral CXL treatment for progressive keratoconus. All patients underwent a complete ophthalmological examination and corneal topography at baseline and 1 year. Subgroup analyses were performed according to the age (<30 and≥30 years), gender, preoperative corrected distance visual acuity (CDVA, <0.3 and ≥0.3 logMAR (log of the minimum angle of resolution)), preoperative maximum keratometry (K, <54 and ≥54 D), baseline topographic cone location (central, paracentral, and peripheral), and preoperative thinnest pachymetry (<450 and ≥450 μm) to determine the associations between preoperative patient characteristics and outcomes (changes in visual acuity and maximum keratometry) of CXL treatment.

Results

In the entire study population, mean CDVA and maximum K significantly improved after CXL treatment (P<0.001). Patients with a preoperative CDVA of 20/40 Snellen equivalent or worse (≥0.3 logMAR) experienced more visual improvement after CXL treatment (P<0.001). However, an age ≥30 years and a baseline thinnest pachymetry less than 450 μm were found significantly associated with more flattening in maximum keratometry (P=0.024, P=0.005 respectively). Gender, preoperative maximum K, and baseline topographic cone location did not show significant effect on postoperative visual acuity and maximum keratometry (P>0.05).

Conclusions

In patients with progressive keratoconus, age, baseline visual acuity, and baseline thinnest pachymetry seem to affect the success of the CXL treatment.     

Intrastromal corneal ring segments for management of keratoconus

Keratoconus is a progressive corneal ectasia, which can be managed both by conservative measures like glasses or contact lenses in non-progressive cases or surgical procedures like collagen crosslinking (CXL) with or without adjuvant measures like intrastromal corneal rings segments (ICRS) or topography guided ablation. Various kinds of ICRS are available to the surgeon, but it is most essential to be able to plan the implantation of the ring to optimize outcomes.

Aims:

The aim of this study is to evaluate the visual outcome and progression in patients of keratoconus implanted with ICRS.

Materials and Methods:

Two different types of ICRS-Intacs (Addition Technology) and Kerarings (Mediphacos Inc.) were implanted in 2 different cohorts of patients and were followed-up to evaluate the outcome of the procedure. All patients underwent a complete ocular examination including best spectacle corrected visual acuity, slit lamp examination fundus examination, corneal topography and pachymetry. The ICRS implantation is done with CXL to stop the progression of the disease. Improvement in uncorrected visual acuity (UCVA), best spectacle corrected visual acuity and topographic changes were analyzed.

Results:

A significant improvement in keratometry and vision was seen in both groups.

Conclusion:

ICRS have been found to reduce corneal irregularity and flatten keratometry with improvement in UCVA and best corrected visual acuity.     

超声乳化白内障吸除术前后不同测量中心患者角膜参数的差异和一致性

目的　探讨超声乳化白内障吸除术前后不同测量中心患者角膜参数的差异和一致性。方法　选取2020年10月至2021年5月在潍坊眼科医院行超声乳化白内障吸除术及Pentacam检查的白内障患者共148例（148眼）。根据Pentacam测量模式“以角膜顶点为中心”或“以瞳孔为中心”分为角膜顶点组和瞳孔中心组。术前及术后3个月,通过Pentacam测量手术前后以角膜顶点为中心和以瞳孔为中心2 mm、4 mm、6 mm圆环和区域模式下患者角膜前表面屈光力（ASF）、角膜真实净屈光力（TNP）和总角膜屈光力（TCRP）;以角膜顶点为中心和以瞳孔为中心测量的同一指标之间采用Kendall W值进行一致性分析。结果　术前圆环模式下:角膜顶点组4 mm ASF、4 mm TNP、6 mm TNP、4 mm TCRP均较瞳孔中心组高,6 mm TCRP较瞳孔中心组低（均为P<0.05）;其余指标两组间差异均无统计学意义（均为P>0.05）。术前区域模式下:角膜顶点组4 mm ASF、2 mm TNP、4 mm TNP、6 mm TNP、4 mm TCRP均较瞳孔中心组高（均为P<0.05）;其余指标两组间差异均无统计学意义（均为P>0.05）。术后3个月仅圆环模式下角膜顶点组2 mm ASF较瞳孔中心组高,差异有统计学意义（P<0.05）;其余指标两组间差异均无统计学意义（均为P>0.05）。术前及术后3个月不同模式下两组患者各指标Kendall W值位于0.978～0.999间,各项结果一致性较好（均为P<0.05）。结论　超声乳化白内障吸除术前后患者角膜不同区域和不同中心范围内部分角膜参数有所变化,总体比较以角膜顶点为中心和以瞳孔为中心测量的角膜参数一致性较好。     

跨上皮快速角膜胶原交联术治疗进展期圆锥角膜

目的:研究跨上皮快速角膜胶原交联术(CXL)治疗进展期圆锥角膜的临床效果和安全性。方法:前瞻性自身前后对照研究。收集自2016-08/2019-11在我院进行跨上皮快速CXL的进展期圆锥角膜患者37例47眼,分析患者术前,术后1、3、6、12mo的裸眼视力(UCVA)和最佳矫正视力(BCVA)、屈光状态、角膜透明度、角膜前表面最大K值(Kmax)、角膜最薄点厚度、角膜内皮细胞计数、眼压。结果:术后1、3、6、12mo患者UCVA较术前提高,但总体比较无差异(F=1.372,P=0.261)。患者术后1、3、6、12mo的BCVA均较术前提高,总体比较有差异(F=3.308,P=0.019),进一步比较发现术后3、6、12mo的BCVA与术前比较有差异(P=0.04、0.01、0.007)。患者术后1、3、6、12mo的球镜度数、柱镜度数、Kmax、角膜最薄点厚度与术前总体比较无差异(F=0.293、1.378、2.448、1.970,P=0.881、0.258、0.061、0.116)。术后1mo患者角膜内皮细胞计数与术前比较无差异(t=1.156,P=0.25)。患者术后各时间点眼压与术前比较无差异(F=1.221,P=0.321)。术后7眼出现角膜Haze(1级~2级),术后3~6mo有5眼Haze消退,角膜恢复透明,1眼遗留角膜云翳,1眼角膜中央基质线状混浊,但均未对视力造成影响。结论:跨上皮快速CXL可以显著提高圆锥角膜患者BCVA,稳定患者屈光状态、角膜形态和厚度,阻止或延缓圆锥角膜进展,使患者获得更好的视功能,同时手术时间短,术后并发症少,具有较好的安全性。     

Accelerated versus standard corneal cross linking in the treatment of ectasia post refractive surgery and penetrating keratoplasty: a medium term randomized trial

AIM: To compare the clinical outcomes of the standard corneal cross linking (CXL) and the accelerated CXL in patients with progressive corneal ectasia post refractive surgery and penetrating keratoplasty. METHODS: Totally 120 eyes of 83 patients scheduled to receive either standard CXL (3 mW/cm2 for a period of 30min) or accelerated CXL (18 mW/cm2 for a period of 5min). The main outcomes for comparison were the change in: maximum-K reading (K-max), manifest refractive spherical equivalent (SE), central corneal thickness (CCT), and the best corrected distance visual acuity (CDVA). RESULTS: One hundred and eleven eyes completed the study. The main outcome measurement was the K-max reading. Both group showed significant improvement in the value postoperatively at 6 and 12mo. The mean change in the standard group was 1.21±0.11 D and in the accelerated group was 0.90±0.05 D at the end of 12mo postoperatively, with no statistically significant difference between the 2 groups. Similarly, CDVA improved significantly from their preoperative value in the standard group by 2.98±0.11 letters, and in the accelerated group by 2.20±0.06 letters, with no statistically significant difference between the two groups. Both of the SE, and CCT showed no statistically significant difference at the end of follow up period in each group. CONCLUSION: Both standard CXL and accelerated CXL are safe and effective treatment in halting ectasia after corneal refractive surgery. The accelerated CXL results are comparable to the standard CXL with short time exposure of the cornea to ultraviolet irradiation, leading to reduced operation time, reduced operative ocular discomfort, and corneal haze.     

Corneal crosslinking for keratoconus in Japanese populations: one year outcomes and a comparison between conventional and accelerated procedures

Purpose

We retrospectively investigated the efficacy of corneal crosslinking (CXL) on progressive keratoconus in a Japanese population and compared the outcomes of conventional and accelerated CXL.

Study design

A retrospective cohort study

Methods

A total of 108 consecutive eyes in 95 patients (75 men; 21.9 ± 6.2 years) with progressive keratoconus were enrolled. The epithelium was ablated in all eyes. After presoaking the corneal stroma in riboflavin, UV-A was irradiated at 3.0 mW/cm² (conventional CXL) for 30 min on 23 eyes and 18.0 mW/cm² for 5 min (accelerated CXL) on 85 eyes. Best spectacle-corrected visual acuity (BSCVA), manifest refraction, keratometric value, corneal thickness, corneal endothelial cell density (ECD), intraocular pressure, and complications were evaluated at 1, 3, 6, and 12 months after the procedure.

Results

BSCVA, manifest refraction, ECD, and corneal thickness did not change significantly after both procedures. The keratometric value was significantly decreased from the preoperative value at 12 months (p < 0.001). Progression to more than 1.0 D after CXL was observed in 10 eyes (9.3%). The ΔKmax was negatively associated with preoperative Kmax (p < 0.001) and positively associated with preoperative thinnest corneal thickness (p < 0.001). Both treatment modules showed no significant difference in all parameters.

Conclusion

CXL was as effective in treating keratoconus in Japanese patients as in individuals of other ethnicities. Overall, CXL could be performed using either the conventional or accelerated approach to halt the progression of keratoconus in Japanese populations.