Outcomes of Boston keratoprosthesis in aniridia: a retrospective multicenter study

PURPOSE: To evaluate the long-term outcomes of keratoprosthesis as an alternative surgical procedure in the management of aniridic keratopathy. DESIGN: Retrospective, multicenter case series. METHODS: Fifteen adult patients (16 eyes) with aniridia who were deemed at high risk for regular donor corneal transplantation underwent a Boston type I keratoprosthesis procedure for visual rehabilitation. Device retention rate, preoperative and postoperative visual acuity, and intraoperative and postoperative complications were studied. RESULTS: The mean age of the patients was 45 (median 50) years. Six of the patients were females. Eleven patients had previously undergone donor corneal transplantations (average two grafts), with failure. In 10 patients, the keratoprosthesis surgery was combined with other procedures such as cataract extraction, tube shunt implantation, vitrectomy, and intraocular lens removal. No intraoperative complications were encountered. The follow-up ranged from two months to 85 months, with a median of 17 months. All devices remained in situ throughout the entire follow-up period. The visual acuity improved in all but one patient from a median of counting fingers (light perception to 20/300) to 20/200 (hand motions to 20/60). Comorbid preoperative conditions particularly optic nerve and foveal hypoplasia limited the final postoperative vision. No endophthalmitis or extrusion of the device occurred. One device required repair procedure without necessitating a removal. CONCLUSIONS: Keratoprosthesis offers significant vision benefits in this patient group.     

Penetrating keratoplasty combined with vitreoretinal surgery for severe ocular injury with blood-stained cornea and no light perception

OBJECTIVE: To evaluate the effects of treatment of severe ocular injury with blood-stained cornea and no light perception by combined penetrating keratoplasty and vitreoretinal surgery, and to analyze the relevant factors. METHODS: Records of 7 severely injured eyes of 7 patients with blood-stained cornea and no light perception who underwent penetrating keratoplasty combined with vitrectomy using a temporary keratoprosthesis were evaluated retrospectively. The preoperative visual acuity was no light perception in all injured eyes with a mean intraocular pressure of 3 mm Hg and a range from 2 to 5 mm Hg. The average interval from emergency wound closure to vitrectomy was 18 days with a range from 12 to 21 days. The mean follow-up was 28 months with a range from 26 to 30 months. RESULTS: The postoperative visual acuity was better than light perception in 5 eyes with the best corrected visual acuity from light perception to 0.06. The retina was attached in 5 eyes. The postoperative intraocular pressure ranged from 5 to 15 mm Hg with a mean of 12 mm Hg; it was significantly higher than the preoperative one (p < 0.05). The postoperative complications mainly included temporary intraocular elevation (1 eye), corneal neovascularization (4 eyes), corneal rejection (4 eyes), retinal detachment (2 eyes) and ocular atrophy (2 eyes). CONCLUSION: Penetrating keratoplasty combined with vitrectomy using a temporary keratoprosthesis is a safe and effective method in treating severe ocular injury with blood-stained cornea and no light perception.     

Cornea sparing by endoscopically guided vitreoretinal surgery

PURPOSE: To report a series of eyes with acute severe corneal edema and vitreoretinal complications treated with endoscopic vitreous surgery without a keratoprosthesis to the cornea. DESIGN: Retrospective, small, noncomparative case series. PARTICIPANTS: Seven patients with unilateral acute severe corneal edema, poor view of the fundus, and vitreoretinal complications were reviewed. Five eyes were postcataract surgery, one eye was postpenetrating intraocular blunt trauma by a ferrous foreign body, and one eye had endophthalmitis. INTERVENTION: Vitreous surgery was performed on each eye under the guidance of endoscopy. Topical steroid treatment was administered to the cornea for several weeks after the vitreoretinal surgery, until the corneal edema had been completely resolved. MAIN OUTCOME MEASURES AND RESULTS: The edematous corneas recovered within an average of 9 weeks (range, 6-13 weeks). The preoperative visual acuity ranged from 6/90 to hand motion at 0.5 m, and the final postoperative visual acuity was 6/30 or better after an average follow-up of 14 months (range, 3-23 months). CONCLUSIONS: (1) Endoscopic surgery for vitreoretinal complications in eyes with acute severe corneal edema can obviate keratoprosthesis and keratoplasty. (2) By minimizing further damage to the corneal endothelium, endoscopic vitreoretinal surgery might benefit corneal recovery.     

复合型人工角膜植入治疗重度角膜盲及并发症处理

目的 探讨钛支架复合型人工角膜植入治疗重度角膜盲的临床价值,以及并发症的处理.方法 回顾性系统病例研究.2002年3月至2005年6月期间中山大学中山眼科中心共完成永久性人工角膜植入9例(单侧眼9只),均为男性,年龄28～52岁.所有患者均为双眼损伤,受伤时间为1.5～5.0年.其中碱烧伤6只眼,爆炸伤3只眼,术前视力均为光感,其中2例光定位不准;均为多次角膜移植以及眼表重建手术失败的难治性重度角膜盲患者.手术分两阶段:一期手术显微镜下行钛支架复合型人工角膜植入联合自体耳软骨移植加固,二期行人工角膜前膜剪开,建立镜柱光学通路.术后评价视力恢复情况,分析并发症的发生原因,探讨相应的处理对策.结果 患者随诊时间1～3年.术后7只眼裸眼视力≥0.1,其中2只眼经镜片矫正后达到0.6.术前光定位不准的2例患者术后视力为0.02和0.04.术后并发症的发生情况为复发性人工角膜前膜5例,进行前膜切除,其中1例联合施行自体唇黏膜移植;角膜局限性融解1例,进行脱细胞真皮加固;人工角膜后膜1例,显微镜下施行后膜钩除术.以上并发症经相应处理均得到控制.随访期内所有人工角膜均保持原位,未发生人工角膜排出、房水渗漏.结论 人工角膜移植是使严重角膜盲患者复明的有效手段,联合自体耳软骨加固可减少并发症的发生,提高人工角膜植入的生物相容性.(中华眼科杂志,2009,45:104-109)     

AlphaCor™ keratoprosthesis: postoperative development of six patients

Purpose  AlphaCor™ (Argus Biomedical Pty. Ltd., Perth, Australia) is an artificial, soft, one-piece keratoprosthesis (KPro) indicated for severe corneal conditions not treatable by a donor graft. To evaluate the efficacy and visual restoring of six patients with complete corneal opacification and deep neovascularizations treated with AlphaCor™. Methods  A retrospective review of six patients with a history of corneal opacification treated with keratoprosthesis surgery. AlphaCor™ synthetic cornea was implanted into the corneal stroma. During the follow-up time, slit-lamp and ultrasound examinations, best corrected visual acuity (BCVA), and intraocular pressure measurements were performed. Results  Six eyes with corneal scarring and vascularizations in three to four quadrants of six patients to years of age underwent a keratoprosthesis procedure. The follow-up time was 13–36 months; mean 23 months. The operation procedure was not limited by severe complications. The preoperative BCVA was hand movement to light perception. The postoperative BCVA ranged between 20/200 and 80/100. Intraocular pressure was controlled in all cases. Three patients developed a melting of the anterior corneal lamella. The keratoprosthesis had to be explanted (15–34 months after implantation) and was replaced by a donor cornea. Conclusions  Further evaluation is needed to evaluate the role of AlphaCor™ as a keratoprosthesis.     

Boston type 1 keratoprosthesis for severe blinding vernal keratoconjunctivitis and Mooren’s ulcer

Indications for the Boston keratoprosthesis differ throughout the world depending on the prevailing regional causes of end-stage corneal disease. We report the short term anatomical and functional outcomes of the Boston type 1 keratoprosthesis for severe bilaterally blinding vernal keratoconjunctivitis and Mooren’s ulcer. A retrospective chart review was conducted of 2 patients who underwent several unsuccessful ocular surface reconstruction procedures before Boston type 1 keratoprosthesis implantation. The anatomical and visual outcomes of the Boston type 1 keratoprosthesis at 1 year of follow-up were assessed clinically and by anterior segment optical coherence tomography imaging. The keratoprosthesis was retained in both the eyes at 1 year postoperatively with a best-corrected visual acuity of 20/30 in both patients. To our knowledge this is the first report of successful Boston keratoprosthesis implantation for these two unusual indications.     

Legeais BioKpro III keratoprosthesis implantation: long term results in seven patients

AIMS: The long term results of the Legeais BioKpro III keratoprosthesis are presented for seven patients with severe corneal scarring. METHODS: The study took place at Moorfields Eye Hospital, London. Patients had either end stage ocular surface disease or corneal opacification after multiple failed graft surgery, with the potential for significant visual improvement. After insertion the device was covered with a conjunctival flap or buccal mucous membrane graft, which was later opened to expose the optic. The outcome measures were vision, complications, and retention of the device. RESULTS: The BioKpro III was inserted into seven patients with severe corneal scarring: ocular cicatricial pemphigoid, measles keratitis, thermal injury, Stevens-Johnson syndrome, aniridia, chemical injury, and congenital rubella. The follow up was 18-48 months. The keratoprosthesis failed in six, because of extrusion occurring 2-28 months postoperatively. Retroprosthetic membranes occurred in three patients, and endophthalmitis in one. Vision improved from hand movements to 6/12 in the only patient who retained the KPro; however he was troubled by mucus accumulation on the optic. CONCLUSIONS: The one success has been in a patient with thermal burns. The remaining results have been poor, with the KPro extruding in six of the seven patients.     

Five year follow up of biocolonisable microporous fluorocarbon haptic (BIOKOP) keratoprosthesis implantation in patients with high risk of corneal graft failure

AIM: To study the anatomical and visual performance following implantation of a model of artificial cornea and to evaluate the postoperative long term complications. METHODS: 11 eyes of 11 patients with bilateral corneal blindness considered as potentially having high risk of failure of penetrating corneal keratoplasty were implanted with biocolonisable Kpro keratoprosthesis (BIOKOP I, FCI, Rantigny, France) in the period between January 1996 and May 1998. Only one eye was implanted in all patients and followed up for a period of 60 months. The visual outcome, anatomical and functional stability, complications, and the general performance of the keratoprosthesis were evaluated. RESULTS: The keratoprosthesis (BIOKOP I) only 36.3% remained in position to date. In the patients' last visit five eyes (45.4%) were blind and one (9.0%) showed a slight improvement in the best corrected visual acuity (BCVA) in comparison to preoperative tests. Six eyes (54.5%) showed improved BCVA before having postoperative complications. Four eyes underwent replacement of a BIOKOP I Kpro with a BIOKOP II as a result of extrusion. The keratoprostheses remained anatomically in situ for a mean of 25.5 months and their functional performance period was limited to a mean of 22 months. CONCLUSION: Corneal keratoprosthesis (BIOKOP I, II) does not provide a stable anatomical relation with the surrounding ocular structures. Its ability to restore vision is limited to a short postoperative period in eyes implanted with severe ocular surface disease.     

Boston keratoprosthesis restoring vision in an unusual case of end-stage limbal stem cell deficiency following exposure to Euphorbia latex

We report the functional outcome of a patient who had undergone Boston keratoprosthesis type I for extensive ocular surface damage caused by latex of Euphorbia. The milky sap or latex of the Euphorbia plant is highly toxic and an irritant to the skin and eye. Damage to the eye ranges from mild to severe corneal edema, epithelial defects, anterior uveitis, secondary elevated intraocular pressure and, rarely, limbal stem cell deficiency with corneal neovascularization. A restrospective review was conducted of this patient for more than 1 year. During this period he was given subconjunctival bevacizumab injection to regress the corneal vascularization without much benefit, before finally performing Boston keratoprosthesis type I. The patient was evaluated periodically for both anatomical and visual outcome. At the end of 1-year follow-up the keratoprosthesis is well retained with a best-corrected visual acuity of 20/40 in the affected eye.     

Deep anterior lamellar keratoplasty combined with autologous limbal stem cell transplantation in unilateral severe chemical injury

PURPOSE: To evaluate the efficacy of deep anterior lamellar keratoplasty combined with autologous limbal stem cell transplantation for ocular surface reconstruction and visual rehabilitation in eyes with unilateral, late-stage, severe chemical injury. METHODS: This was a retrospective, noncomparative, interventional case series that included 7 eyes of 7 patients, with severe unilateral late stage chemical injury, exhibiting corneal vascularization, conjunctivalization, and extensive corneal scarring were treated at the C. J. Shah Cornea Service, Sankara Nethralaya, a tertiary care center. Surgical procedures included releasing symblepharon adhesions, excising epibulbar fibrous tissue, superficial keratectomy to remove fibrovascular tissues over cornea, deep anterior lamellar dissection, grafting a lamellar corneal button, and transplanting autologous limbal graft, with or without amniotic membrane transplantation. The main outcome measures were relief of patient symptoms, postoperative recovery of the ocular surface, corneal clarity, corneal epithelial stability, and best corrected visual acuity. RESULTS: The mean duration between the injury and surgery was 24.4 +/- 21.8 months. No intraoperative complications were noted. Successful epithelialization was achieved in all eyes. The reconstructed corneal surface remained stable during the entire follow-up period (mean follow-up, 16.57 +/- 5.12 months). All patients had resolution of ocular symptoms. Remarkable improvement in vision was noted in all (85.7%) except 1 eye in which recovery was limited due to amblyopia. The average best corrected visual acuity at last follow-up was 20/50. No complications were noted in the donor fellow eye. CONCLUSIONS: DALK combined with autologous limbal transplantation can restore a healthy, stable ocular surface, besides providing a clear cornea that remarkably improves the visual acuity, in patients with unilateral, late stage, severe chemical injury.