A new surgical technique for deep stromal, anterior lamellar keratoplasty

AIMS: To describe a new surgical technique for deep stromal anterior lamellar keratoplasty. METHODS: In eye bank eyes and sighted human eyes, aqueous was exchanged by air, to visualise the posterior corneal surface--that is, the "air to endothelium" interface. Through a 5.0 mm scleral incision, a deep stromal pocket was created across the cornea, using the air to endothelium interface as a reference plane for dissection depth. The pocket was filled with viscoelastic, and an anterior corneal lamella was excised. A full thickness donor button was sutured into the recipient bed after stripping its Descemet's membrane. RESULTS: In 25 consecutive human eye bank eyes, a 12% microperforation rate was found. Corneal dissection depth averaged 95.4% (SD 2.7%). Six patient eyes had uneventful surgeries; in a seventh eye, perforation of the lamellar bed occurred. All transplants cleared. Central pachymetry ranged from 0.62 to 0.73 mm. CONCLUSION: With this technique a deep stromal anterior lamellar keratoplasty can be performed with the donor to recipient interface just anterior to the posterior corneal surface. The technique has the advantage that the dissection can be completed in the event of inadvertent microperforation, or that the procedure can be aborted to perform a planned penetrating keratoplasty.     

Deep anterior lamellar keratoplasty for post-LASIK ectasia

PURPOSE: To describe 2 cases of post-laser in situ keratomileusis (LASIK) ectasia managed with deep anterior lamellar keratoplasty (DALK). METHODS: Clinical findings, surgical interventions, and outcomes are reported. The surgical technique of DALK is described. RESULTS: Two patients developed progressive loss of vision after LASIK surgery with enhancement procedure(s). Corneal ectasia was diagnosed on the basis of clinical findings, progressive central corneal thinning on pachymetry, and topographical changes with irregular astigmatism and inferior corneal steepening. Both patients underwent uneventful DALK surgery, in which the anterior 80% of the central corneal stroma was replaced by a donor button and sutured in place. The postoperative recovery was uneventful, except for mild interface haze in 1 case, which resolved within 2 weeks of surgery. However, 1 patient underwent additional surgery, including clear lens extraction with intraocular lens placement, astigmatic keratotomies, and photorefractive keratectomy (PRK) to achieve good unaided visual acuity. At last follow-up, at least 2 years after DALK, both patients were satisfied with their vision. Their uncorrected visual acuity (UCVA) was 20/60+ and 20/40- in their operated eyes, improving to 20/40+ and 20/30- with minimal refractive corrections. The grafts and lamellar interfaces were clear. CONCLUSIONS: We believe that DALK should be considered as an alternative to penetrating keratoplasty for the surgical management of post-LASIK ectasia.     

A quick surgical technique for deep, anterior lamellar keratoplasty using visco-dissection

PURPOSE: To describe a new surgical technique for deep, anterior lamellar keratoplasty using a viscoelastic for dissection of Descemet's membrane (DM) from the posterior stroma. METHODS: Through a paracentesis, aqueous was exchanged by air to visualize the posterior corneal surface-i.e., the air-to-endothelium interface. Using the interface as a reference plane, a 30 gauge needle was inserted into the cornea to just anterior to DM. Viscoelastic was injected to separate DM from the posterior stroma, and a recipient, anterior lamella was excised. A full-thickness donor button was sutured into the recipient bed, after stripping its DM. RESULTS: In 25 eye bank eyes, the procedure could be completed in 20 eyes; in 5 eyes, DM ruptured during visco-dissection. With light microscopy, dissection depth was located at the level of DM. In two patient eyes the procedure could be completed. In a third patient eye DM ruptured during visco-dissection, and the procedure was converted into a penetrating keratoplasty. CONCLUSION: Using visco-dissection, a lamellar keratoplasty can be performed quickly, with the donor-to-recipient interface just above the recipient DM, i.e., with a nearly perfect anatomical replacement of all corneal stroma. There is substantial risk of rupture or microperforation of DM during surgery.     

部分板层角巩膜移植术治疗角膜皮样瘤

目的：观察部分板层角巩膜移植术治疗角膜皮样瘤的疗效。方法：对17例角膜皮样瘤患者,用比瘤体直径大0．25mm的环钻划界,在病灶处做部分板层角膜及巩膜切除,在供体眼球相应部位钻取直径比植床大0．25mm的植片,行部分板层角巩膜移植术。术后随访4月－6月。结果：17例（17眼）中,15例（15眼）上皮光滑,植片透明。2例（2眼）术后3周出现层间新生血管,经抗排斥治疗后消退。无一例肿瘤复发。全部恢复正常眼表结构。结论：相应部位的部分板层角巩膜移植术是治疗角膜皮样瘤的较理想的方法。     

A new surgical technique for keratoglobus-tectonic lamellar keratoplasty followed by secondary penetrating keratoplasty.

PURPOSE: To develop a technique that achieves satisfactory visual rehabilitation in keratoglobus, without the problems of re-epithelialization failure and with minimal risk of graft rejection. METHODS: A patient with bilateral keratoglobus and visual acuities of light perception in the right eye and 6/60 in the left underwent a tectonic lamellar keratoplasty to the right eye. The cornea was first trephined to the depth of the anterior stroma within the limbus. A lamellar dissection technique then was used to tunnel into sclera under the limbus to preserve stem cells. The host corneal epithelium was completely débrided, and a donor corneoscleral button, denuded of its endothelium, was laid on top. A paracentesis was made, and aqueous was aspirated until the anterior chamber had collapsed enough to take up a more physiologic shape. The donor corneoscleral graft was sutured into the prefashioned scleral bed with long, interrupted sutures. Once in situ, the donor graft was débrided of epithelium, and the host limbus was sutured on to it, covering its scleral component. Six months later, a penetrating keratoplasty was performed. The same procedure was performed on the left eye 2 years later. RESULTS: The right eye maintained a best-corrected visual acuity of 6/60 for 16 months after the penetrating graft until the graft decompensated, leaving a final acuity of counting fingers. The left eye maintained a best-corrected visual acuity of 6/18. CONCLUSION: Tectonic lamellar keratoplasty to preserve the host limbus, followed by secondary penetrating keratoplasty, is a realistic alternative to other procedures for the surgical management of keratoglobus.     

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)     

局部切除合并部分异体板层角巩膜移植治疗角膜皮样瘤

目的 观察局部切除合并异体板层角巩膜移植治疗角膜皮样瘤的临床效果。方法 对107例110眼角膜皮样瘤用比瘤体大0．5mm的环钻划界，行病灶处角巩膜组织板层切除，于供体眼球相应部位钻取形状和厚度相似的板层角巩膜植片，植片比植床直径大0．25mm，角膜侧行连续缝合，巩膜侧行间断缝合。结果 随访6个月～5年，所有植片愈合良好，7眼出现植片下新生血管及植片轻度水肿，抗排斥治疗后血管萎缩、消退。术后正常眼表结构恢复快，视力及角膜散光较术前改善（P〈0．05）。2例复发，无层间植入等并发症。结论 局部彻底切除合并相应部位的异体板层角巩膜移植是治疗角膜皮样瘤的较理想的方法。     

Deep lamellar keratoplasty as surgical management of anterior and posterior segment injuries to the eye.

PURPOSE: To report on the feasibility of combined deep lamellar keratoplasty and vitreoretinal surgery in one patient with corneal opacity associated with retinal detachment. METHODS: A 35-year-old man presented with a major hematocornea and retinal detachment after experiencing a right ocular trauma with corneoscleral wound 1 month earlier. We elected to perform deep lamellar keratoplasty to perform vitreoretinal surgery through the bared Descemet's membrane within the same surgical procedure. RESULTS: Deep lamellar keratoplasty offered perfect visibility of the anterior and posterior segments of the eye through the bared Descemet's membrane during the 4-hour operation. Descemet's membrane was resilient enough to maintain remarkable tightness of the anterior chamber throughout vitreoretinal surgery procedures (vitrectomy, peeling of epiretinal membranes, encircling scleral buckling). Unfortunately, despite our efforts and extended operative time, the retina could not be restored to its position because of the high baseline level of ocular impairment. CONCLUSION: The combined procedure (deep lamellar keratoplasty and pars plana vitrectomy) appeared to be a good and feasible alternative to the temporary keratoprosthesis usually applied in that situation.     

Simplified technique for deep anterior lamellar keratoplasty

PURPOSE: To describe a new technique for performing deep anterior lamellar keratoplasty (DALK) that can be done without special instruments and where deep stromal dissection can be performed under direct visualization. METHODS: In this prospective, noncomparative case series, DALK was performed by first creating a scleral pocket incision to initiate corneal dissection and continuing further dissection under direct visualization after partial trephination. Fourteen eyes of 13 patients with corneal pathology not involving endothelium were operated on by using the new technique. RESULTS: Accidental entry into the anterior chamber occurred in only 1 eye (7.1%). After a mean follow-up of 10.3 +/- 4 months, the graft was clear in 12 eyes (92.3%), and all 12 eyes had a best-corrected visual acuity of 20/60 or better at this time. CONCLUSIONS: Our technique for DALK offers an alternative to the currently used techniques.     

Central lamellar keratoplasty with peripheral intralamellar tuck: a new surgical technique for keratoglobus

PURPOSE: To report a new technique of lamellar keratoplasty in a case of keratoglobus. METHODS: A patient with bilateral keratoglobus with maximal thinning in the juxtalimbal periphery underwent a lamellar procedure in the right eye. The visual acuity was 3/60. Refraction was not possible due to severe irregular astigmatism, and the central pachymetry was 430 microm. A central 8.5 mm diameter lamellar dissection along with a peripheral intrastromal pocket up to the limbus was fashioned. The donor corneal button (12 mm) denuded of its endothelium was beveled at the periphery to create a flange. This flange was tucked into the peripheral pocket and the graft was sutured with interrupted nylon sutures. RESULTS: No intra-or postoperative complication was encountered. Reepithelialization was complete within 1 week. At 1 month postoperatively, the preoperative keratometric astigmatism of >12 D decreased to <2.75 D. The spectacle-corrected visual acuity at 1 month was 6/18. CONCLUSIONS: This new technique of central lamellar keratoplasty with intralamellar tucking of the peripheral flange for keratoglobus not only provides optical clarity and tectonic support but also helps in preservation of the host limbal stem cells.     

A new surgical technique of microkeratome-assisted deep lamellar keratoplasty with a hinged flap

We describe a new surgical technique of microkeratome-assisted deep lamellar keratoplasty for treating patients with corneal stromal disease and normal endothelium. A microkeratome is used to create a hinged anterior stromal flap in the host cornea, and the diseased stroma is resected or ablated. A complementary donor stromal button, prepared using a microkeratome and an artificial anterior chamber, is transplanted prior to repositioning of the flap. The flap may be lifted at a later date, and an excimer laser used to correct residual refractive errors. Notwithstanding the preliminary and theoretical nature of this report, this technique may improve the outcomes of deep lamellar keratoplasty and may allow for decreased postoperative complications. Arch Ophthalmol. 2000;118:1112-1115     

Vitrectomy technique in anterior segment surgery.

Instruments designed primarily for vitreous surgery were used in 74 anterior segment operations. In each case the instrument was introduced into the eye through a limbal incision. This preliminary report shows that this new approach offers several advantages over conventional methods in selected cases. It is of particular value in the management of presenile and complicated cataracts and in the removal of capsulo-lenticular remnants and pupillary membranes. A larger number of cases and longer follow-up are necessary to define further the specific indications and limitations of this technique.     

部分板层角巩膜移植术治疗角膜皮样瘤的疗效分析

目的:观察部分板层角巩膜移植术治疗角膜皮样瘤的疗效。方法:我们对15例角膜皮样瘤进行了部分板层角巩膜移植术。术后随访6mo～4a。结果:所有病例术后外观明显改善。15例15眼中14例14眼角膜植片透明。只有1例术后2wk出现排异反应经治疗植片恢复透明。结论:部分板层角巩膜移植术是目前治疗角膜皮样瘤的一种较理想的治疗方法。     

A new donor cornea harvesting technique for posterior lamellar keratoplasty

AIMS: To describe a technique for posterior lamellar keratoplasty donor preparation. METHODS: In an experimental study eight human donor research corneas were mounted onto an artificial anterior chamber and deep stromal pockets dissected. Four corneas were mounted in the standard endothelial side down orientation and dissected using standard instruments (group 1). Another four corneas were mounted endothelial side up and dissected using a flat spatula (group 2). Trephined lamellar graft thickness was assessed by ultrasound pachymetry. The grafts were also analysed using vital staining of the endothelium and standard histological preparation. RESULTS: Achieved posterior graft thickness was 118 (SD 32) microm (group 1) and 92 (23) microm (group 2) (p=0.324). Percentage of devitalised endothelial cells was 0.86% (1.48%) (group 1) and 3.9% (2.9%) (group 2) (p=0.185). The dissections using both harvesting techniques remained in plane and were smooth. CONCLUSIONS: A blunt spatula and endothelium side up orientation on an artificial anterior chamber can be used to create posterior lamellar dissections without compromising endothelial cell number or planarity when compared to standard endothelium side down harvest.