Changes in endothelial cell density following penetrating keratoplasty and deep anterior lamellar keratoplasty

AIM: To compare the corneal endothelial cell density (ECD) of clear grafts after penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK). METHODS: The study included 44 and 54 patients treated with PK and DALK, respectively, between March 2006 and April 2010. Corneal ECD was examined using specular microscopy at postoperative 1, 3, 6, 12, and 18 months, and the values were compared. RESULTS: Corneal ECD reduction in the PK group was 7.4%, 15.2%, 23.5%, and 28.9% at 3, 6, 12 and 18 months respectively after surgery, compared with 4.2 % in the first month (P<0.01). These figures were 3.0%, 6.7%, 7.2%, and 7.7% at 3, 6, 12 and 18 months respectively, compared with 2.2 % in the first month in the DALK group (P>0.05). CONCLUSION: Compared with DALK,PK significantly reduced ECD of the clear grafts. These results suggest that survival of endothelial cells in grafts is better after DALK than after PK.     

Comparison of contrast sensitivity and visual acuity between deep anterior lamellar keratoplasty and penetrating keratoplasty in patients with keratoconus

AIM: To evaluate postoperative visual acuity and contrast sensitivity results following deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in patients with keratoconus (KC). METHODS: All the patients’ records with KC who had PK or DALK surgery between May 2010 and May 2011 were retrospectively reviewed. Sixty patients who underwent successful corneal transplantation for KC: 30 eyes underwent DALK and 30 eyes underwent PK were included in this study. Preoperative and postoperative mean logarithm of the minimum angle of resolution (logMAR) uncorrected visual acuity (UCVA), logMAR best spectacle-corrected visual acuity (BSCVA) and intraocular pressure (IOP) were evaluated. Contrast sensitivity tests (CS) were done preoperative and 2 months after all sutures had removed. All surgeries were performed under regional anesthesia (retrobulbar anesthesia) by 1 surgeon (B.K.) who was experienced in penetrating and lamellar keratoplasty techniques.RESULTS: The mean age of the DALK group was 29.67±4.95 (range 18-40) years and the PK group was 28.7±3.53 (range 18-39) years. Preoperatively there was no significant difference in the logMAR UCVA, logMAR BSCVA and IOP between the DALK (1.281±0.56; 0.97±0.85; 12.07±2.12mmHg) and PK (1.34±0.21; 0.98±0.21; 13±2.12mmHg) groups. One-year after surgery there was no significant difference in the mean logMAR UCVA and IOP between the DALK (0.46±0.37; 11.73±2.1mmHg) and PK (0.38±0.21; 12±2.12mmHg) groups. The mean contrast sensitivity was evaluated by CC-100 Topcon LCD at 1.5, 2.52, 4.23, 7.10 and 11.91 cycles per degree (cs/deg) spatial frequencies before and 2 months after the all sutures had removed. CONCLUSION: All patients with keratoconus in both DALK and PK groups performed good visual function postoperatively. The mean contrast sensitivity increased considerably at all spatial frequencies compared with preoperative levels in the DALK and PK groups. The mean post-operative evaluation of contrast sensitivity measurements was not significantly different between the two groups.     

Comparison of deep lamellar keratoplasty and penetrating keratoplasty for lattice and macular corneal dystrophies

PURPOSE: To compare the therapeutic outcomes after deep lamellar keratoplasty (DLKP) and penetrating keratoplasty (PKP) in patients with lattice corneal dystrophy (LCD) and macular corneal dystrophy (MCD). DESIGN: Age-matched control study. METHODS: We reviewed the clinical records of 84 eyes with LCD or MCD who had DLKP (41 eyes) or PKP (43 eyes). Primary pathology consisted of 60 eyes with LCD and 24 eyes with MCD. DLKP was performed by either removing stromal tissue gradually, or by viscodissection of Descemet's membrane. Graft clarity, best-corrected visual acuity (BCVA), endothelial density, and complications were compared between DLKP and PKP, as well as between LCD and MCD. RESULTS: All 84 eyes showed a postoperative improvement in visual acuity. The median final BCVA was not significantly different between PKP and DLKP groups. Endothelial cell loss rates were similar for DLKP and PKP. While the MCD-DLKP group showed progressive decrease in endothelial density, this was not observed in the LCD-DLKP group after surgery. In the DLKP group, most of the complications occurred intraoperatively or in the early phase, whereas late phase complications such as endothelial rejection and secondary glaucoma were the main complications in the PKP group. CONCLUSIONS: PKP is no longer an automatic choice for the surgical treatment for LCD and MCD; DLKP seems to be a safe alternative. While DLKP is a favorable method for LCD, MCD may not be a good candidate, as it might show progressive decrease in the corneal endothelium postoperatively.     

无缝线深板层角膜内皮移植术的研究进展

角膜内皮失代偿可严重影响视力,以往多采用的穿透性角膜移植手术(PKP)具有术后高度散光、移植片排斥等并发症,严重限制了术后视力的提高.如果能够单纯地进行后弹力层和内皮细胞层的移植,将减少手术操作所带来的受体角膜损伤并能更好地恢复术后视力.近年来,无缝线深板层角膜内皮移植手术的优点已逐渐获得公认;其中深板层角膜内皮细胞移植手术(DLEK)手术难度较大,限制了其在临床的广泛开展.而通过剥除受体角膜的后弹力层和内皮层来制作植床的角膜内皮移植手术即角膜后弹力层剥除内皮细胞移植手术(DSEK)已经取得了较好的手术效果.本文归纳、分析了DSEK的手术方法、效果及并发症等.     

角膜深板层内皮移植术的临床初步研究

目的　探讨用微型角膜刀行角膜深板层内皮移植术的适应证、手术原则、临床疗效及并发症的预防及处理。方法　用微型角膜刀对 6例患者 6只患有大疱性角膜病变眼行深板层角膜内皮移植术。其中 1例为前段玻璃体切除加后房型人工晶状体缝线固定术联合角膜深板层内皮移植术 ,1例为临时人工角膜下玻璃体切除加球内异物取出术联合角膜深板层内皮移植术。术后随访 6～ 9个月。结果　 5例患者视力明显提高 ,患者术后平均角膜内皮细胞密度为 (2 4 81± 2 12 )个 /mm2 ,角膜中央厚度平均为 (5 4 9± 6 1) μm ,散光为 (2 0 4± 1 19)D ,未发生严重并发症。 结论　用微型角膜刀行角膜深板层内皮移植术是治疗大疱性角膜病变的可选术式。与传统的穿透性角膜移植相比 ,该术式有望成为角膜内皮移植的技术平台 ,但远期疗效尚需继续随访。     

Comparison of refractive changes after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus

Purpose  

To compare refractive changes occurring after deep anterior lamellar keratoplasty (DALK) or penetrating keratoplasty (PKP) in patients with keratoconus.     

Scattered light and visual function in a randomized trial of deep lamellar endothelial keratoplasty and penetrating keratoplasty

PURPOSE: To compare vision, intraocular forward light scatter and corneal backscatter between deep lamellar endothelial keratoplasty (DLEK) and penetrating keratoplasty (PK) for endothelial dysfunction. DESIGN: A randomized clinical trial. METHODS: Thirteen eyes (12 patients) were randomized to DLEK with a 9 mm scleral incision, and 15 eyes (14 patients) were randomized to PK. The primary outcome was high-contrast best spectacle-corrected visual acuity (BSCVA) at 12 months after surgery; intraocular forward light scatter and corneal backscatter were measured at one, three, six, and 12 months after surgery. RESULTS: BSCVA at 12 months was 0.34 +/- 0.16 logMAR (logarithm of the minimum angle of resolution) for DLEK and 0.25 +/- 0.21 logMAR for PK (P = .23; minimum detectable difference at 12 months was 0.23 logMAR). The change in postoperative forward light scatter after DLEK correlated with the change in BSCVA (r = -0.66; P < .001; n = 11). Corneal backscatter was higher after DLEK than after PK at three and six months in the anterior third (P < or = .005), at one through 12 months in the middle third (P < .001), and at one through six months in the posterior third (P < or = .02) of the cornea. Backscatter after DLEK did not return to normal through 12 months (P < .001). CONCLUSIONS: BSCVA was similar at one year after DLEK and PK. Improvement in BSCVA after DLEK correlated with decreasing forward light scatter. Increased backscatter after DLEK originated not only from the posterior cornea (interface) but also from the host cornea, which might limit visual outcomes after posterior lamellar keratoplasty.     

Randomized clinical trial of deep lamellar keratoplasty vs penetrating keratoplasty

PURPOSE: To prospectively compare the safety and efficacy of deep lamellar keratoplasty (DLKP) and penetrating keratoplasty (PKP). DESIGN: Prospective, randomized clinical trial. METHODS: Consecutive 26 eyes of 24 patients who had stromal opacity without endothelial abnormalities were randomly assigned to either PKP or DLKP. Best-corrected visual acuity (BCVA), contrast visual acuity, glare test, intraocular pressure, corneal topography, endothelial density, and pachymetry were measured before and after surgery. RESULTS: Two eyes in the DLKP had rupture of the Descemet membrane and one of the eyes developed endothelial decompensation. One eye in the PKP group showed decreases in vision due to secondary glaucoma. None of the eyes developed immunologic rejection. The PKP group showed a tendency of faster recovery in BCVA than the DLKP group, but the difference was not statistically significant. Contrast visual acuity, glare test, and corneal topography did not show significant differences between the two groups. The intraocular pressure was significantly higher at 12 months in the PKP group (P =.004), but not in the DLKP group (P =.41) compared with preoperative values. While the PKP group showed progressive decrease in endothelial density over 24 months, this was not observed in the DLKP group after surgery. Difference in endothelial density at 24 months reached statistical significance (P =.04). CONCLUSIONS: We found that DLKP was superior to PKP in its safety such as continuous decreases of endothelium or increases in intraocular pressure. However, endothelial damage can also occur in DLKP, especially in cases of intraoperative Descemet membrane rupture. With the development of easier surgical techniques, DLKP may be a first choice of keratoplasty in most eyes without endothelial abnormalities.     

深板层角膜移植术与穿透角膜移植术治疗圆锥角膜临床疗效的Meta分析

背景临床上正在广泛开展各种角膜移植术以治疗圆锥角膜,其中深板层角膜移植术（DLKP）是目前的研究热点之一,但其临床疗效及安全性备受关注。目的探讨临床研究中DLKP和穿透角膜移植术（PKP）治疗圆锥角膜的有效性与安全性。方法应用循证医学的研究方法,检索美国国立医学图书馆（PubMed数据库）、循证医学数据库（Cochranelibrary）、荷兰医学与文摘（EMbase）和中国知网（CNKI）,对有关DLKP和PKP治疗圆锥角膜临床疗效的随机对照研究与非随机对照试验进行方法学和质量评价,并根据评价结果对临床随机对照试验（RCT）进行Meta分析。采用RevMan5．0统计学软件进行统计分析。结果共纳入已发表的关于DLKP和PKP治疗圆锥角膜的临床对照研究文献11篇,样本量2950眼,其中RCT3篇,非随机对照试验文献8篇。结果显示,DLKP组患者术后最佳矫正视力（BCVA）≥0．5的眼数少于PKP组,差异有统计学意义（RR=0．91,95％CI：0．84～0．99,P=0．030）;两组BCVA≥1．0者差异不明显。DLKP组术后残余屈光不正的等效球镜度数较PKP组更偏向于近视,但差异无统计学意义（RR=-0．60,95％CI：-1．43～0．23,P=0．150）,而术后散光情况两组间差异无统计学意义[加权平均数（WMD）=0．21,95％CI：-0．48～0．91,P=0．550];在保护角膜内皮方面,DLKP组术后平均角膜内皮细胞计数多于PKP组;在移植排斥反应方面,DLKP组术后总移植排斥反应发生率较PKP低（RR=0．47,95％CI：0．27～0．80,P=0．006）,尤其是内皮型移植排斥反应,DLKP组基本不发生（RR=0．06,95％CI：0．01～0．31,P=0．001）。结论PKP在术后BCVA和屈光力方面有一定优势,但DLKP术后发生内皮型排斥反应和内皮衰竭的概率低,安全性更好。因此,DLKP为治疗轻度、中度圆锥角膜提供了一个安全、有效的手术方式选择。     

深板层角膜移植术与穿透性角膜移植术治疗真菌性角膜溃疡的效果比较

目的 比较深板层角膜移植术(DLKP)和穿透性角膜移植术(PKP)两种术式治疗真菌性角膜溃疡的效果.方法 回顾性系列病例研究.2004至2006年在宁波鄞州人民医院眼科中心临床诊断明确的真菌性角膜溃疡患者17例(17眼),其中8例行DLKP,平均年龄38.6岁,9例行PKP,平均年龄51.0岁.术后随访时间12～24个月,记录两组患者的最佳矫正视力、角膜屈光状态、角膜内皮计数及并发症.计数资料采用x2检验,计量资料采用独立样本t检验进行分析.结果 两组患者术后的视力均较术前提高,最好的最佳矫正视力达1.0,两组差异无统计学意义.DLKP组术后散光小于PKP组,差异有统计学意义(x2=12.07,P<0.05),两组散光度均低于5.00 D.术后6个月、12个月角膜内皮细胞计数DLKP组较PKP组高,差异有统计学意义(t=3.899、7.618,P<0.05).深板层角膜移植患者排斥反应的发生率较穿透性角膜移植患者低(x2=132.26,P<0.01).结论 真菌性角膜溃疡患者DLKP术后最佳矫正视力略优于PKP,角膜散光度比PKP低,并发症也较少.DLKP能减少排斥反应的发生,降低手术的失败率,是治疗真菌性角膜溃疡的一种安全有效的方法.     

深板层角膜移植及穿透角膜移植治疗圆锥角膜的对比研究

目的:观察圆锥角膜患者行深板层角膜移植和穿透角膜移植术后视力、角膜曲率及角膜内皮细胞的变化。方法:将2003-01/2009-07在我院行手术治疗的42例47眼圆锥角膜患者分为两组,一组接受深板层角膜移植(27眼),另一组接受穿透角膜移植(20眼)。观察两组患者术后3,6,12,18mo的裸眼视力、最佳矫正视力、角膜地形图改变和角膜内皮细胞状态。结果:深板层角膜移植组术后裸眼视力平均提高4行,最佳矫正视力平均提高7行,无排斥反应发生。穿透角膜移植术后裸眼视力平均提高5行,最佳矫正视力平均提高8行,有5例发生排斥反应。两种术式相比,术后散光程度无明显差异,深板层角膜移植组角膜内皮细胞丢失速率低于穿透角膜移植组。结论:对于非急性期圆锥角膜患者深板层角膜移植术优于穿透角膜移植术。     

深板层角膜移植术与穿透性角膜移植术治疗圆锥角膜的临床分析

目的 探讨深板层角膜移植术（DLKP）与穿透性角膜移植术（PKP）对圆锥角膜的不同临床疗效。方法采用病例对照研究设计,选择自2003年4月至2006年4月期间于我院行DLKP11例（11只眼）和PKP18例（18只眼）的29例圆锥角膜患者资料。对术前、术后的未矫正视力（UCVA）、最好矫正视力（BCVA）、植片情况、散光状况及手术并发症等进行分析。结果DLKP术后9例患者BCVA高于0．5,PKP术后14例患者BCVA高于0．5。DLKP组术后的平均球镜度数（DS）为（-1．21±3．36）D,平均柱镜度数（DC）为（-4．03±1．87）D,PKP组术后平均DS和DC分别为（-3．86±2．43）D和（-3．43±2．31）D,两组间比较差异均无统计学意义（DS：t=2．135,P=0．46;DC：t=-0．643,P=0．528）。共焦显微镜检查显示,DLEK组与PKP组术后角膜植片的上皮细胞、上皮细胞基底层及前弹力层角膜在形态上基本相似,均表现为植片基质细胞胞核略小,排列稍显紊乱,有裂隙样暗纹。DLKP组患侧眼内皮细胞的形态基本正常,平均密度为（2311．72±439．73）个／mm^2,对侧眼为（2477．81±535．92）个／mm^2,二者差异无统计学意义（t=1．06,P=0．78）;PKP组患侧眼内皮细胞面积较大,细胞大小不均匀,非六角形细胞比例高,平均密度为（1642．17±583．41）个／mm^2,明显低于对侧眼（2739．05±401．77）个／mm^2,二者之间比较差异有统计学意义（Z=7．32,P=0．006）。DLKP组的并发症主要是术中后弹力层穿孔、缝线松脱及层间浑浊等。PKP组的并发症主要是缝线松脱、眼压升高、排斥反应及内皮功能衰竭。结论DLKP术后的屈光状况与PKP术接近,虽然手术操作难度较高,但是术后发生内皮排斥和内皮衰竭的机率低、安全性高。（中华腰群杂志,2007,43：583-588）