Late corneal hydrops after penetrating keratoplasty for keratoconus

PURPOSE: To report 2 cases of corneal hydrops occurring in eyes with previously healthy corneal grafts. METHODS: Retrospective case series. A report of 2 presenting cases. Both patients underwent a full ophthalmic clinical examination and anterior segment optical coherence tomography (OCT). RESULTS: Two patients with longstanding corneal grafts for keratoconus presented with an acute painful red eye and reduced vision. They were found to have acute hydrops with breaks in and detachments of Descemet membrane. CONCLUSIONS: Keratoconic patients with longstanding corneal grafts who present acutely with corneal edema must be carefully examined not only for signs of graft rejection or failure but also for acute hydrops. Important differentiating signs may be a Descemet break or detachment and the presence of stromal edema across the donor-host corneal interface.     

Rapid visual recovery after penetrating keratoplasty for keratoconus

Purpose: To ascertain the level and speed of visual recovery after penetrating keratoplasty for keratoconus. Method: A retrospective review was performed of 100 consecutive cases of penetrating keratoplasty for keratoconus, performed between 1999 and 2005. Review assessed visual function and the speed at which patients achieved a functional best corrected visual acuity (BCVA) of ≥6/12 either with glasses or phoropter. Analysis of visual, refractive and keratometric results were made on 76 eyes that had reached 6 months after suture removal. Intraoperative and postoperative complications including graft rejections were recorded. Results: Post keratoplasty, 43.4%, 78.9% and 96.1% of patients achieved a BCVA of 6/12 or better by 1, 3 and 6 months, respectively. The mean time to achieve a BCVA of 6/12 was 9.6 weeks. Only 5.3% of patients required a rigid gas permeable contact lens. Overall 42.4% of patients had unaided visual acuity of 6/12 or better at 12 months. The mean refractive cylinder and standard deviation was 2.78 ± 1.6 D, and the mean spherical equivalent was ?1.12 ± 2.9 D. There were no significant intraoperative complications, and although 3.9% of eyes had at least one graft rejection episode there were no graft failures. Conclusion: Penetrating keratoplasty is an effective method for treating advanced keratoconus. By 3 months almost all patients are able to achieve a BCVA of 6/12 or better with progressive improvement over time. This technique allows almost half of patients to achieve an unaided vision of 6/12 or better with sutures in situ.     

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）     

圆锥角膜行板层角膜移植术和穿透性角膜移植术后屈光状态的比较

目的探讨圆锥角膜行板层角膜移植术(LKP)和穿透性角膜移植术(PKP)术后屈光特征及变化趋势。方法对因圆锥角膜行LKP 30只眼与PKP 25只眼进行回顾性研究,通过比较两组术后不同时间点以及全拆线前后的最佳矫正视力(BCVA)、等效球镜(SE)、平均角膜曲率及角膜散光值,分析两种术式术后屈光状态的特征及变化趋势。结果 LKP与PKP术后BCVA均呈逐渐上升趋势,全拆线后LKP平均提高0.27±0.16,PKP为0.25±0.24;等效球镜向近视方向改变,全拆线前后比较LKP改变为(-2.29±4.58)D,PKP为(-6.24±2.71)D,两者之前有差异;平均角膜曲率逐渐增大,全拆线前后比较LKP增大4.11±2.94,PKP为5.71±2.53,两者之间无差异;角膜散光逐渐减小,全拆线前后比较LKP减小5.31±7.96,PKP为1.06+4.47,两者之间有差异。结论圆锥角膜行LKP和PKP两种术式相比,术后均BCVA逐渐上升,等效球镜向近视方向发展,平均角膜曲率增大而散光减小,但LKP较PKP拆线时间早,全拆线前后相比LKP角膜散光变化较大而PKP的等效球镜变化较大。     

Outcomes of penetrating keratoplasty in keratoconus

PURPOSE: Keratoconus (KCN) is one of the most common indications of corneal transplantation in Iran. This study was conducted to determine the outcomes of penetrating keratoplasty (PK) for KCN in patients operated in a private practice setting from 1994 to 2001. METHODS: This longitudinal retrospective study included 164 eyes of 164 patients. Variables included preoperative keratometry, trephination and suturing techniques, donor-recipient disparity, surgical complications, immunologic rejection, graft clarity, postoperative spherical and cylindrical refractive error, keratometry, uncorrected and best spectacle-corrected visual acuity, suture management, and the results of keratorefractive procedures. RESULTS: Patients were followed for a mean period of 33.5 months. Mean postoperative best spectacle-corrected visual acuity (BSCVA) at last follow-up was 0.14 +/- 0.11 LogMAR (20/25); mean spherical error and mean corneal astigmatism were -0.61 +/- 2.6 and 3.4 +/- 1.8 D, respectively. Final visual outcomes were not significantly correlated with trephination and suturing techniques or severity of the ectasia. Although donor-recipient disparity did not affect final astigmatism, more myopic shift was observed with greater disparity, but this finding was not of statistical significance. Overall, 26.8% of the patients required keratorefractive surgery, which resulted in 2.9 D reduction in corneal astigmatism. Immunologic graft rejection occurred in 28% of cases; however, all episodes responded to medical management, and none resulted in graft failure. CONCLUSION: Penetrating keratoplasty is a safe and effective procedure with remarkable optical and visual outcomes for patients with keratoconus who are contact lens intolerant or have unacceptable corrected visual acuity. Neither severity of the disorder nor trephination and suturing techniques significantly affects final visual outcomes. Less graft-recipient disparity (0.25 versus 0.50 mm) seems to induce less myopic shift.     

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。     

Corneal graft rejection after penetrating keratoplasty for keratoconus in Turner's syndrome

PURPOSE: To report a patient with Turner's syndrome who developed graft rejection after penetrating keratoplasty (PK) for keratoconus and to review the ophthalmic literature on the association between keratoconus and Turner's syndrome. METHODS: A woman with bilateral keratoconus and Turner's syndrome (45,XO) was referred for progressive visual loss in the right eye. Best-corrected visual acuity was 20/400 in the right eye. Slit-lamp examination revealed corneal thinning with ectatic protrusion of the central cornea and Vogt's striae in the right eye. The patient underwent PK in the right eye in January 2001. She developed graft rejection in April 2003 and visual acuity dropped to hand motion. After treatment with topical and systemic steroids and systemic cyclosporine A, visual acuity recovered to 20/80 in July 2003. RESULTS: The authors know of only three other reported patients (six eyes) with keratoconus in Turner's syndrome. Five eyes underwent PK with good visual rehabilitation, but one developed immunologic graft rejection 7 years after surgery. On the whole, considering the current report and the other cases described in the literature, graft rejection occurred in 2 out of 6 eyes (33.3%). The graft survival rate was 80% after 2 years and 40% after 7 years. CONCLUSIONS: The results suggest that grafts for keratoconus in patients with Turner's syndrome might have an increased risk of immunologic rejection. Corneal grafts in Turner's syndrome need to be monitored closely. Early detection of graft rejection and aggressive treatment with topical and systemic steroids and systemic cyclosporine A can save the graft and restore useful vision.     

Refractive surgery for graft-induced astigmatism after penetrating keratoplasty for keratoconus.

Of a series of 201 corneal transplants for keratoconus over a 20-year period, 42 grafts (39 eyes of 38 patients) required further surgery because of intolerable astigmatism (range, -3 diopters [D] to -18 D; mean, 8.9 D). Relaxing incisions, compressive resuturing, and augmented relaxing incisions were the techniques used. All procedures resulted in a similar mean reduction in cylinder -3.6 to 5 D, but the outcome with augmented relaxing incisions was less predictable. Six grafts required two or more procedures for a satisfactory outcome. All patients had corrected visual acuity of 20/30 or better after surgery, and 75% had visual acuity of 20/20 or better. The cumulative time until 90% of the grafts had useful vision was 32 months after refractive surgery. Relaxing incisions offer the prospect of more rapid visual rehabilitation than compressive resuturing.     

圆锥角膜穿透性角膜移植术后远期疗效动态分析

目的 动态分析圆锥角膜穿透性角膜移植术后的远期效果。方法 收集本院22例27只眼因圆锥角膜行部分穿透性角膜移植术12m至192m的患者，分别进行视力、屈光度、散光及角膜地形图的检查，并对数据进行分析。结果 术前与术后1周，拆线前、后与术后2y～5y视力比较，差异有显著意义（P＜0．01或P＜0．05）。术后2y～5y与术后5y～16y相比差异无显著性（P＞0．05）。术后各随访阶段散光度比较差异无显著意义（P＞0．05）。圆锥角膜术后两种类型角膜地形图参数差异有显著意义（P＜0．01）。结论 圆锥角膜穿透性角膜移植术后疗效显著，无复发倾向，穿透性角膜移植术是圆锥角膜重要的治疗方法。     

Corneal endothelium after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus: a four-year comparative study

Purpose:

To compare the status of corneal endothelium and central corneal thickness within the first four postoperative years after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in patients with keratoconus.

Materials and Methods:

Thirty-nine eyes (Group A) which had PK and 44 eyes (Group B) which had DALK for the treatment of keratoconus were included in this retrospective study. The endothelial cell density (ECD), the mean endothelial cell area and the coefficient of variation of cell area were assessed with a non-contact specular microscope, and the central corneal thickness (CCT) was measured with an ultrasound pachymeter.

Results:

Mean ECD loss rate at two years was 36.24% in Group A and 18.12% in Group B (P<0.001). Mean ECD loss rate at four years was 47.82% in Group A and 21.62% in Group B (P<0.001). Mean annual ECD loss rate was calculated 14.12% per year in Group A and 5.78% per year in Group B. In the PK group, increase in mean CCT was 15.60% in two years and 15.03% in four years, while in the DALK group, mean CCT increased by 8.05% in two years and 9.31% in four years.

Conclusions:

As the majority of ectatic disorders such as keratoconus occur in young people, long-term endothelial cell survival following treatment with keratoplasty is essential for the long-term visual ability. Our finding that corneal endothelial cell loss in the DALK group occurs at a slower rate than in the PK group suggests DALK as a safer alternative to PK in these selected patients.     

Myopia following penetrating keratoplasty for keratoconus.

The frequent occurrence of spherical myopia after penetrating keratoplasty for keratoconus is partly the result of the excessive dioptric power of the grafted cornea which occurs when the diameter selected for the donor button is greater than the diameter of the host incision. This excessive power could be reduced by eliminating disparity between the diameters of the graft and host. To determine what proportion of the myopia in these eyes would persist as a result of axial myopia the axial lengths of 60 patients grafted for keratoconus and 25 emmetropic controls were compared. A keratometry, objective refraction, and contact probe ultrasonic biometry were performed on all eyes. A comparison of the results with a representational schematic eye indicated that the mean spherical refractive error of the grafted keratoconic eyes (-4.83 dioptres) was the combined effect of steepness of the corneal graft (mean radius of curvature 7.46 mm) and an abnormally great axial length (mean 24.84 mm). The increased axial length was mainly the result of elongation of the posterior segment of the globe with a small contribution from an increased anterior chamber depth. Though axial myopia is common in keratoconus, a further study of 70 keratoconic eyes that had not been grafted showed no statistically significant correlation between the posterior segment length and the severity of corneal ectasia. These data suggest that even if excessive corneal power is eliminated after penetrating keratoplasty for keratoconus the associated axial myopia would still produce a mean spherical refractive error of at least -2.8 dioptres.     

Urrets-Zavalia syndrome following penetrating keratoplasty for keratoconus

Background

Urrets-Zavalia syndrome (UZS) consists of a fixed dilated pupil associated with iris atrophy. It is a poorly understood complication following penetrating keratoplasty (PKP) for keratoconus (KC). In this work, we aim to establish the incidence, visual outcomes, and an understanding of UZS.

Methods

This was a retrospective single-center study in a tertiary eye service in the United Kingdom of consecutive patients with UZS following PKP for KC in a 10-year period. Post-operative complications, including raised intraocular pressure (IOP), were recorded. UZS patients and age-matched control patients who had undergone PKP for KC without developing UZS attended a comprehensive clinical assessment. Anterior segment indocyanine green (ICG) angiography assessed iris perfusion.

Results

The incidence of UZS was 16.2 %. There was no difference in LogMAR VA or Pelli–Robson contrast sensitivity between groups. There was higher first-day post-operative IOP in UZS (p?=?0.02). UZS patients had increased pupil size (p?=?0.09) with reduced response to pilocarpine 2 % (p?<?0.001). ICG angiography revealed delayed/reduced iris vasculature filling in UZS compared with normal filling patterns of controls.

Conclusions

Elevated post-operative IOP within 24 h was a significant factor in the development of UZS. Visual function in UZS patients was unaffected. UZS patients developed longstanding mydriasis with reduced reactivity to topical pilocarpine 2 %. ICG angiography confirmed iris vessel ischemia; supporting the theory that iris ischemia resulting from occlusion of iris root vessels due to elevated IOP causes UZS. We advocate rigorous intraoperative management of ocular viscoelastic devices and aggressive postoperative IOP control in patients undergoing PKP for KC.     

Recurrence of keratoconus in two corneal grafts after penetrating keratoplasty

PURPOSE: To report the recurrence of postkeratoplasty keratoconus in 2 corneal grafts harvested from the same donor. DESIGN: Interventional case reports. METHODS: A 21-year-old-man with advanced keratoconus in his right eye and a 28-year-old-woman with corneal leucoma in her right eye underwent penetrating keratoplasty with 2 grafts coming from the same donor. Approximately 1.5 years after grafting, corneal irregularity and astigmatism caused visual acuities of the patients to decrease to counting fingers. Clinical findings and corneal topography suggested the recurrence of keratoconus. A repeat keratoplasty was performed in both patients. RESULTS: Histopathology of the excised corneal grafts was consistent with keratoconus and confirmed the preoperative diagnosis. CONCLUSIONS: Recurrence of keratoconus in a patient who had no preexisting keratoconus and in 2 corneal grafts coming from the same donor suggested transmission of the disorder from the donor instead of true recurrence.     

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.