Immunologic graft reactions after nonmechanical corneal trephination using the excimer laser

Background: Nonmechanical trephination has been established as the standard procedure in penetrating keratoplasty (PK) for avascular corneal diseases at our institution. The purpose of this study was to analyze the incidence and reversibility of immunologic graft reactions after nonmechanical trephination and to detect potentially causative factors. Patients and methods: Out of a total series of 400 nonmechanical PKs, 286 consecutive procedures with sufficient follow-up performed between 07/1989 and 09/1997 were included in the study (104 × keratoconus, 78 × Fuchs' dystrophies, 31 ×bullous keratopathies, 28 × ulcers, 25 × avascular scars, 12 × stromal dystrophies, 4 × buphthalmos, 4 × others; 202 × PK only, 84 × combined procedures; 276 first PK). The age of the 138 females and 148 males at the time of surgery ranged from 16 to 89 (mean 55 ± 19) years. The recipient and donor trephinations were performed from the epithelial side using an 193-mm excimer laser (MEL50 or MEL60, Aesculap-Meditec, 1.5 ×1.5 mm spot mode, 16–24 mJ/pulse, repetition rate 30 or 25/s; metal masks). The shape of the recipient trephination was either circular with four or eight “orientation teeth” (n = 251; 5.0–8.0 mm diameter) or elliptical (n = 35, 6.0 × 7.0 to 7.5 × 8.5 mm diameter). In 62 % of procedures fresh or short-term-preserved donor tissue was used, and in 38 % of procedures the donor tissue was organ-culture-preserved. Results: During a mean follow-up of 22 ± 18 months (maximum 7.7 years), 10 acute diffuse (3 irreversible; 1.0 %) and 3 chronic focal endothelial graft reactions occurred (4.5 %) not earlier than 4 months and not later than 35 months after PK. Elective procedures (3.5 %) resulted in significantly (P = 0.01) less reactions than acute corneal ulcers (14.3 %). After 1, 2 and 3 years, the cumulative reaction rates (Kaplan-Meier values) were 1.3 %, 6.3 % and 13.9 % in elective procedures, none of which, however, occurred after 26 elliptical trephinations. With fresh or short-term-preserved donor tissue (4.2 %), graft reactions did not happen more frequently but earlier (12 ± 6 months) than with organ-culture-preserved donor tissue (2.2 %, 30 ± 6 months). In patients with keratoconus (4.9 %), reactions occurred more frequently (P = 0.05, LogRank) and earlier than in patients with Fuchs' dystrophy (1.3 %). Conclusions: In addition to well-established optical advantages, nonmechanical trephination seems to have no immunologic drawbacks.      

Classification of corneal topography after penetrating keratoplasty

Background: Semiquantitative classification of corneal topography after penetrating keratoplasty has the potential for focusing information about the areal dioptric power of the cornea. The purpose of this study was to objectify the procedure of manual semiquantitative classification using a Fourier transform of corneal topography power data and to correlate both methods. Patients and methods: Fifty patients each (30 keratoconus, 20 Fuchs dystrophy) underwent nonmechanical trephination (excimer laser MEL60, Aesculap-Meditec, Jena) in penetrating keratoplasty. All procedures (7.5-mm trephination diameter in Fuchs, 8.0 mm in keratoconus, double-running 10–0 nylon suture) were done by one surgeon. Pre-, intra- and postoperative treatment were identical. At the follow-up examinations, the keratometric astigmatism, qualitative and quantitative criteria of the automatic videokeratography, visual acuity and refraction were assessed. Corneal topography was classified both manually and based on Fourier coefficients. Results: After a mean follow-up of 24 ± 5 months, keratometric net astigmatism was 3.0 and 2.7 D with keratoconus and Fuchs dystrophy. Corneal topography analysis showed a higher orthogonality of the bow-tie shape and less asymmetry between opposite hemimeridians with increasing follow-up after keratoplasty. The semiquantitative classification showed a statistically significant correlation with the classification based on Fourier coefficients, especially with higher astigmatism and after suture removal (P = 0.04/0.01 before/after suture removal). Discussion: After nonmechanical trephination, the semiquantitative classification of corneal topography can be synthetized using Fourier analysis of corneal dioptric power data. In the future, this method may be favored for prediction of potential best-corrected visual acuity after penetrating keratoplasty.      

深板层角膜移植-一种新的光学性角膜移植技术

深板层角膜移植适合于角膜基质异常及/或混浊但内皮健康者,其恢复角膜透明性的效果与穿透性角膜移植相当。这一手术的最大优点是能避免术后排斥反应、无须内皮健康的供体。经过多年的改进,手术技术已有明显进步,但仍存在操作难度较大、费时、受体基质去除不彻底、术中后弹力膜微穿孔的缺点。随着手术技术的进一步完善,临床上相当部分的穿透性角膜移植可被深板层角膜移植取代。(眼科,2006,15:156-158)     

Mechanism of immune tolerance induced by donor derived immature dendritic cells in rat high-risk corneal transplantation

AIM: To study the role of immature dendritic cells (imDCs) on immune tolerance in rat penetrating keratoplasty (PKP) in high-risk eyes and to investigate the mechanism of immune hyporesponsiveness induced by donor-derived imDCs.METHODS:Seventy-five SD rats (recipient) and 39 Wistar rats (donor) were randomly divided into 3 groups:control, imDC and mature dendritic cell (mDC) group respectively. Using a model of orthotopic corneal transplantation in which allografts were placed in neovascularized high-risk eyes of recipient rat. Corneal neovascularization was induced by alkaline burn in the central cornea of recipient rat. Recipients in imDC group or mDC group were injected donor bone marrow-derived imDCs or mDCs of 1×10⁶ respectively 1 week before corneal transplantation via tail vein. Control rat received the same volume of PBS. In each group, 16 recipients were kept for determination of survival time and other 9 recipients were executed on day 3, 7 and 14 after transplantation. Cornea was harvested for hematoxylin-eosin staining and acute rejection evaluation, Western blot was used to detect the expression level of Foxp3.RESULTS: The mean survival time of imDC group was significantly longer than that of control and mDC groups (all P<0.05). The expression level of Foxp3 on CD4⁺CD25⁺T cells of imDC group (2.24±0.18) was significantly higher than that in the control (1.68±0.09) and mDC groups (1.46±0.13) (all P<0.05).CONCLUSION: Donor-derived imDC is an effective treatment in inducing immune hyporesponsiveness in rat PKP. The mechanism of immune tolerance induced by imDC might be inhibit T lymphocytes responsiveness by regulatory T cells.     

The effects of changed biomechanical parameters on measurements of intraocular pressure in keratoconus patients

Background: Keratoconus is associated with changes in the corneal structure, such as defects of Bowman's layer, a decrease of corneal thickness etc. They result in alterations of some of the biomechanical parameters of the cornea, namely, rigidity and elasticity. The present study was performed to examine how impression tonometry and applanation tonometry for determination of intraocular pressure (IOP) are affected by the changed biomechanical parameters associated with keratoconus. Patients and methods: We examined 20 normal subjects (40 eyes) and 17 keratoconus patients (25 eyes). The corneal thickness was measured by ultrasound pachymetry in the corneal center. In the keratoconus patients, an additional measurement was made at the conus peak. The corneal curvature was determined using the TMS keratoscope. The IOP measurements were made with the Schi?tz tonometer (10 g). For comparison, additional IOP measurements in the corneal center and, in the keratoconus group, on the conus peak were made with the applanation tonometer. Results: The normal subjects had a central corneal thickness of 548 ± 30 μm, compared to 505 ± 42 μm in the corneal center and 425 ± 41 μm on the conus peak in keratoconus patients. The average corneal curvature was 43.3 ± 1.8 D in the normal subjects and 47.8 ± 4.1 D in keratoconus patients. Applanation tonometry produced results on 11.33 ± 1.43 mm Hg in the normal group (corneal center) compared to values of 12.00 ± 2.55 mm Hg (corneal center) and 7.30 ± 1.95 mm Hg (conus peak) in the keratoconus cohort. The coefficient of rigidity was 0.0236 ± 0.0026 μl⁻¹ in the normal subjects, compared to 0.0173 ± 0.0050 μl⁻¹ in the keratoconus patients. Conclusion: The morphological changes associated with keratoconus may cause tonometry errors.      

角膜后弹力层剥除内皮移植术治疗大泡性角膜病变的初步疗效观察

目的 探讨角膜后弹力层剥除内皮移植手术的适应证、手术方法以及对大泡性角膜病变的疗效与并发症的处理.方法 非随机回顾性系列病例研究.选择2006年9月至2007年10月于中山大学中山眼科中心住院的8例(8只眼)大泡性角膜病变患者行角膜后弹力层剥除内皮移植术.术中剥除患眼角膜中央部直径7.75 mm的后弹力层和病变的内皮层,再将植床周边部基质表面刮粗糙,然后按常规角膜内皮移植术的方法植入内皮植片.术后观察植片与植床贴合和植片移位等情况.随访3～9个月,记录患者视力、植片透明度、角膜散光及内皮细胞密度.结果 8例患者术后植片与植床贴合良好,未出现植片移位.术后第1天,1例患者出现继发性闭角型青光眼,术后48 h后缓解.8例患者术后植片透明,术前存在眼痛的6例患者术后眼痛缓解.8例患者术后视力均提高,最好矫正视力为0.3～0.7,平均角膜散光度数为(1.90±0.70)D,平均内皮细胞密度为(2014±192)个/mm2.结论 与深板层角膜内皮移植术比较,角膜后弹力层剥除内皮移植术的操作较简单,对受体角膜和前房的创伤更小.术中将植床周边部基质表面刮粗糙,可有效预防术后植片移位.     

Assessment of refractive change following photorefractive keratectomy: keratometry versus computerized videokeratography

Summary The purpose of this study was to determine which corneal curvature values most closely correlated to change in subjective manifest refraction following excimer laser photorefractive keratectomy (PRK). Methods: Excimer laser PRK was performed on ten eyes of ten patients (mean age: 37.3 years). Preoperative refractive errors ranged from –2.25 to –8.75 diopters. Preoperatively and 1 month postoperatively, we determined the spherical equivalent of the manifest refraction (corrected for a 12 mm vertex distance) and measured corneal power using standard keratometry (Bausch and Lomb keratometer) and computerized videokeratography (EyeSys Corneal Analysis System). We collected five corneal values: standard keratometry, videokeratography-derived simulated keratometric readings calculated using the axial, instantaneous and refractive formulas, and corneal refractive power over the central 3-mm zone (effective refractive power); apart from the traditional refractive index of the cornea (n = 1.3375), we used the refractive value of the anterior corneal stroma (n = 1.376). For each of the five corneal values, we subtracted the change in corneal power from the change in manifest refraction and calculated the means and standard deviations. Results: The mean differences between the refraction and the corneal values for a refractive index of 1.3375/1.376 were: 0.89 ± 0.54^*/1.26 ± 0.59* for standard keratometry; 1.64 ± 0.75^*/1.37 ± 0.7*, 4.03 ± 1.86^*/3.86 ± 1.87*, and 1.16 ± 0.76^*/0.91 ± 0.74* for the axial, instantaneous, and refractive videokeratography values, respectively; and 0.83 ± 1.03^*/0.39 ± 1.08 for the effective refractive power (*, p < 0.05). Conclusions: In our series, only the values for the effective refractive power, calculated with the refractive index of the anterior stroma of the cornea, were not statistically different from the change in manifest refraction.      

飞秒激光辅助穿透性角膜移植术的早期临床研究

目的:评价应用飞秒激光辅助穿透性角膜移植术(FSPKP)的早期疗效及安全性。方法:回顾性分析46例48眼FS-PKP术病例。术前最佳矫正视力为2.35±1.01(标准对数视力表),角膜病变累及全层,包括圆锥角膜、白斑、外伤性瘢痕等。采用飞秒激光制作不同直径和边缘形状的全层角膜植片与对应植床,进行角膜移植术,术后治疗与常规穿透性角膜移植术(传统PKP)相同。评价指标包括术前及术后1,6,10mo的裸眼视力(UCVA)、最佳矫正视力(BCVA)、角膜散光(CA)值、手术并发症。将同期完成的43例44眼传统PKP病例作为对照组。两组数据采用统计软件SPSS 18.0成组设计的两样本均数比较和χ2检验。结果:所有手术均顺利完成,术后视力均有不同程度的提高;在与传统PKP的比较中,两种术式的术后UCVA在术后1mo时分别是3.48±0.43和2.97±1.14,有显著的统计学差异(P=0.009);术后3mo时UCVA分别是3.86±0.25和3.74±0.73,术后6mo时分别是4.04±0.23和3.98±0.29,均无统计学差异(P=0.146,P=0.56);FSPKP组术后1mo BCVA优于传统PKP手术组,差异有显著统计学意义(P=0.002),而术后6,10mo,两组的BCVA比较无统计学差异(P6mo=0.132,P10mo=0.47);但在术后散光、高眼压、切口裂开等方面FS-PKP组的发生率明显低于传统PKP组,有统计学差异(P<0.05)。结论:与传统的穿透性角膜移植相比,飞秒激光辅助的穿透性角膜移植术后早期的视力恢复快,角膜散光值和并发症的发生率显著降低,体现了这一新技术的临床优越性。     

Can we overcome the challenges of sutures in lamellar keratoplasty?

Lamellar keratoplasty (LK) is a technique which can be followed for both tectonic and optical purposes. We describe a technique of sutureless anterior LK by fixing the donor lenticule to the recipient bed using fibrin glue. LK was performed in an eye with corneal opacity using the manual dissection method. The donor lenticule was cut with a microkeratome after fixing the corneoscleral rim in an artificial anterior chamber. The size of the donor lenticule was 8.5 mm and fixed to the recipient bed with fibrin glue. The surgical time was reduced significantly with this technique. There was an uneventful postoperative period during the follow-up of 12 months. Best corrected visual acuity improved from hand movement to 20/60. Thus, the use of fibrin glue for fixing the anterior lamellar lenticule is a viable option for both optical and anatomical purposes.     

Evidence-Based Endothelial Rehabilitation

ABSTRACT

Endothelial keratoplasty (EK) has replaced penetrating keratoplasty (PKP) as the preferred surgical therapy for corneal endothelial dysfunction. However, recent nationwide corneal graft registry data showed few advantages to EK relative to PKP with respect to graft survival and visual outcomes. This article compares the published outcomes and complications of EK to those of PKP. EK demonstrates superior spectacle corrected visual outcomes, fast recovery, less graft rejection, and higher patient satisfaction, particularly in studies performed by high-volume surgeons/centers. Endothelial cell loss in EK, while higher at early time points, was equivalent or superior at five-years’ follow-up and graft survival was equivalent to or superior to PKP in these centers/studies. Continued standardization and simplification of EK procedures may allow surgeons who perform a lower volume of EK to achieve results that mirror those of high-volume centers/surgeons and close the potential gap in outcomes demonstrated in the registry data.     

DALK und perforierende Laserkeratoplastik bei fortgeschrittenem Keratokonus

Background

In cases of contact lens intolerance and/or central corneal scars, corneal transplantation is indicated for advanced keratoconus. This can be performed as deep anterior lamellar keratoplasty (DALK) or as penetrating keratoplasty (PKP). The German keratoplasty registry shows that the proportion of anterior lamellar grafts in Germany has remained stable at approximately 5?% in recent years.

Methods

Up to now DALK has not been technically standardized but can result in a good visual acuity using the big bubble technique if Descemet’s membrane is laid bare intraoperatively. In 10–20?% a conversion to PKP is required if perforation of Descemet’s membrane occurs. In cases of advanced keratoconus PKP is still the method of first choice especially after corneal hydrops due to rupture of Descemet’s membrane. Non-contact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and those with repeat grafts in cases of keratoconus recurrence due to the graft being too small. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved by a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually depending on corneal size (as large as possible and as small as necessary). Limbal centration is given priority intraoperatively due to optical displacement of the pupil.

Results

Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces vertical tilt and horizontal torsion of the graft in the recipient bed, thus resulting in significantly less all-sutures-out keratometric astigmatism (2.8 D versus 5.7 D), higher regularity of the topography (SRI 0.80 vs. 0.98) and better visual acuity (0.80 vs. 0.63) in contrast to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP.

Conclusions

In cases with optimal course DALK achieves the same visual outcome as mechanical PKP but the healthy endothelium can be preserved and endothelial immune reactions are prevented in keratoconus. In contrast to the undisputed clinical advantages of excimer laser keratoplasty with orientation teeth/notches in keratoconus, the major disadvantage of femtosecond laser application is still the necessity of suction and applanation of the cone during trephination.     

Black diaphragm intraocular lens implantation and penetrating keratoplasty in aphakic eyes with traumatic aniridia

AIM: To evaluate the long-term outcome of implantation of black diaphragm intraocular (BDI) lens combined with penetrating keratoplasty (PKP) for managing aphakic eyes with traumatic aniridia and corneal damage.METHODS: Six aphakic eyes of six patients with traumatic aniridia and corneal damage had BDI lens implantation at Qingdao Eye Hospital, Shandong Eye Institute from June 2008 to November 2011. Medical records of the patients were reviewed. Three patients received PKP and after 12-18months were implanted with BDI lens. The other three patients completed PKP and BDI lens implantation at the same time. The corrected visual acuity, intraocular pressure and number of corneal endothelial cells were monitored.RESULTS: The patients were followed up for an average of 24.3±12.1months (range 14-48 months). All BDI lenses were located well. The best corrected visual acuity got improved in 5 patients (0.1-1.0) and decreased in 1 patient from 0.4 to 0.2. Three patients had normal intraocular pressure (IOP) after implantation. Two patients required antiglaucoma medications to control IOP within the normal range and 1 patient implanted Ahmed glaucoma valve to control IOP. The corneal grafts kept transparent in all eyes and the corneal endothelial counting >1 000/mm², although two patients experienced acute graft rejection and loss more than 30% corneal endothelial cells.CONCLUSION: Implantation of BDI lens combined with PKP is an effective option for managing aphakic eyes with traumatic aniridia and corneal damage. Although the results in our study are encouraging, additional studies of the long-term safety and efficacy are required. A larger study population and longer follow-up may be beneficial.     

Spontaneous Corneal Clearance in the Presence of a Partially Detached Graft after Non-Descemet Stripping Automated Endothelial Keratoplasty

PurposeTo report the explantation of a detached and opaque donor disc as an alternative to secondary keratoplasty in a case of persistent graft detachment followed by spontaneous clearance of the recipient cornea after non-Descemet stripping automated endothelial keratoplasty (non-DSAEK).ResultsFour months after graft explantation, BSCVA was 0.5 and endothelial cell density (ECD) was 1,221 cells/m². After 13 months, BSCVA was still 0.6 while ECD had fell to 800, and 2 years later, the endothelium decompensated. BSCVA was 0.3 and ECD was not measurable.ConclusionsTo our knowledge this is the first report of explantation of an endothelial graft as an alternative to re-keratoplasty in a case of spontaneous corneal clearance. This minimally invasive treatment may be considered in similar cases. However, due to the ongoing loss of endothelial cells after endothelial keratoplasty, a re-keratoplasty may still be needed in the long termKey Words: Spontaneous corneal clearance, Non-Descemet stripping automated endothelial keratoplasty, Contact inhibition     

Safety of prophylactic intracameral moxifloxacin ophthalmic solution after cataract surgery in patients with penetrating keratoplasty

AIM:To determine the safety of prophylactic intracameral moxifloxacin after cataract surgery in patients with penetrating keratoplasty (PKP).METHODS:In this retrospective study of consecutive patients who had phacoemulsification cataract surgery after PKP, were treated with intracameral moxifloxacin 0.5% ophthalmic solution (0.5 mg/0.1 mL). The main outcome measures were anterior chamber reaction, best corrected visual acuity (BCVA), corneal endothelial cell count (ECC), and central corneal thickness (CCT).RESULTS:Fifty-five patients were recruited (26 males, 29 females). The mean age was 54.36±4.97y (range 45-64y). All eyes had improved postoperative BCVA. The mean BCVA was 0.25 preoperatively and 0.57 postoperatively, which was statistically significant (P<0.001). One eye had 3+, 7 eyes had 2+, 12 eyes had 1+ and 8 eyes had trace amount of aqueous cells on the first day after surgery. All eyes had no anterior chamber cells at subsequent follow up examinations. Effective phacoemulsification time was 4.33±1.01s. The mean ECC was 2340.20 cells/mm² preoperatively and 1948.75 cells/mm² 1mo postoperatively (P<0.001). The increase of 21.09 μm in postoperative pachymetry 1mo after surgery was statistically significant (P<0.001).CONCLUSION: No untoward effects were observed after intracameral injection of moxifloxacin (0.5 mg/0.1 mL) in terms of anterior chamber reaction, CCT, ECC, and visual rehabilitation at the conclusion of cataract surgery in patients with PKP.     

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.     

简化DSEK技术在复杂性大泡性角膜病变中的应用

目的观察简化的后弹力层撕除角膜内皮移植术(Descemet’s stripping endothelial keratoplasty,DSEK)治疗复杂性大泡性角膜病变的疗效。设计回顾性病例系列。研究对象2015年12月至2017年8月北部战区总医院接受手术治疗的11例(11眼)复杂性大泡性角膜病变患者。方法所有患者接受了DSEK,术中所有供体植片采用手工剖切制作,平均直径(8.05±0.57)mm,植片均采用滑板法植入。主要指标术后早期植片贴附情况及并发症;随访1年时最佳矫正视力(BCVA)、角膜散光、植片透明度和厚度、内皮细胞密度和手术并发症。结果11眼中8眼术后植片与植床贴附良好;3眼术后植片半脱位,经再次前房注气后植片贴附良好。1眼术后4个月继发开角型青光眼。术后1年BCVA 7例患者≥0.3;平均角膜散光度数为(1.83±0.46)D;11眼植片均透明,平均植片厚度(126±19)μm;平均内皮细胞密度(954±218)个/mm2;11眼均无排斥反应发生。结论复杂性大泡性角膜病变行简化DSEK可获得满意的疗效。     

Laser intrastromal keratoplasty--case report

PURPOSE: To evaluate the feasibility of correcting high hyperopia by means of intrastromal implantation of a laser shaped corneal lenticule prepared from a human donor eye. METHODS: A female patient with high hyperopia and irregular astigmatism resulting from multiple laser in situ keratomileusis procedures and lamellar keratoplasty underwent laser intrastromal keratoplasty. Her preoperative uncorrected visual acuity (UCVA) was 20/300 and best spectacle-corrected visual acuity (BSCVA) was 20/100 with a refraction of +8.00 -1.00 x 130 degrees. Corneal topography showed a highly irregular corneal surface. Central corneal thickness was 398 microm. Lenticule preparation included mechanical de-epithelialization of a human donor eye, keratectomy with a microkeratome, user-designed software combining a photorefractive keratectomy (PRK) treatment for +8.00 D sphere, an ablation zone of 7.0 mm, and a circumferential cut (internal diameter of 6.5 mm) for tissue ablation. Implantation involved re-lifting the flap, positioning the lenticule onto the corneal bed, and repositioning of the flap. RESULTS: The operation was uneventful as was the early postoperative follow-up. BSCVA improved to 20/50 with +1.00 -2.25 x 120 degrees at 2 months postoperatively. Corneal topography showed a more regular cornea with increased curvature in all meridians. Central corneal thickness increased to 600 microm. CONCLUSION: Laser intrastroma keratoplasty may be an option for correcting high hyperopa and irregular astigmatism in eyes with a thin corneal bed.     

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.