Posterior lamellar keratoplasty: DLEK to DSEK to DMEK.
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Corneal Transplantation↗
Biomedical subjects
Gerrit R J Melles
Publications and source records attributed to Gerrit R J Melles.
Descemet membrane endothelial keratoplasty (DMEK).
PURPOSE: To describe Descemet membrane endothelial keratoplasty (DMEK) with organ cultured Descemet membrane (DM) in a human cadaver eye model and a patient with Fuchs endothelial dystrophy. METHODS: In 10 human cadaver eyes and 1 patient eye, a 3.5-mm clear corneal tunnel incision was made. The anterior chamber was filled with air, and the DM was stripped off from the posterior stroma. From organ-cultured donor corneo-scleral rims, 9.0-mm-diameter "DM rolls" were harvested. Each donor DM roll was inserted into a recipient anterior chamber, positioned onto the posterior stroma, and kept in position by completely filling the anterior chamber with air for 30 minutes. RESULTS: In all recipient eyes, the donor DM maintained its position after a 30-minute air-fill of the anterior chamber followed by an air-liquid exchange. In the patient's eye, 1 week after transplantation, best-corrected visual acuity was 1.0 (20/20) with the patient's preoperative refraction, and the endothelial cell density averaged 2350 cells/mm. CONCLUSION: DMEK may provide quick visual rehabilitation in the treatment of corneal endothelial disorders by transplantation of an organ-cultured DM transplanted through a clear corneal tunnel incision. DMEK may be a highly accessible procedure to corneal surgeons, because donor DM sheets can be prepared from preserved corneo-scleral rims.
Corneal Transplantation↗
Endothelial cell density after deep anterior lamellar keratoplasty (Melles technique).
PURPOSE: To measure the recipient endothelial cell loss after the Melles technique for deep anterior lamellar keratoplasty. METHODS: In 21 eyes of 21 patients, a deep anterior lamellar keratoplasty procedure was performed. Before surgery and at 6, 12, and 24 months after surgery, specular microscopy was performed to evaluate the endothelial cell density. For each postoperative time interval, the mean endothelial cell loss relative to the preoperative value was calculated. RESULTS: Mean postoperative endothelial cell loss averaged 283 cells/mm(2) (+/- 293) at 6 months, 335 cells/mm(2) (+/- 309) at 12 months, and 421 cells/mm(2) (+/- 316) at 24 months. Estimate relative endothelial cell density losses obtained by mixed model analysis of variance were 11.1%, 2.0%, and 1.2%, respectively, each time compared with its previous measurement point. Second order comparisons showed that the loss within the first 6 months was significantly higher than after 6 months. CONCLUSION: In deep anterior lamellar keratoplasty, the recipient corneal endothelium showed a small initial drop in endothelial cell density followed by a physiologic rate of cell loss. Cell survival after lamellar keratoplasty may be expected to be better when compared with that following penetrating keratoplasty.
Adult↗
Endothelial cell density after posterior lamellar keratoplasty (Melles techniques): 3 years follow-up.
PURPOSE: To report the midterm endothelial cell density measurements after posterior lamellar keratoplasty (Melles techniques). DESIGN: Cohort study. METHODS: Fifteen consecutive eyes of 15 patients in whom a posterior lamellar keratoplasty procedure was performed for pseudophakic bullous keratopathy or Fuchs' endothelial dystrophy were evaluated. In 11 corneas the donor tissue was inserted through a 9.0-mm sclerocorneal pocket incision (technique A); in four cases the donor was folded and inserted through a 5.0-mm incision (technique B). Specular microscopy was performed at 6, 12, 24, and 36 months after surgery, to measure the endothelial cell density. RESULTS: Mean postoperative endothelial cell density averaged 2,126 cells/mm(2) (+/-548) at 6 months, 1,859 cells/mm(2) (+/-477) at 12 months, 1,385 cells/mm(2) (+/-451) at 24 months, and 1,047 cells/mm(2) (+/-425) at 36 months. CONCLUSION: In posterior lamellar keratoplasty, the donor corneal endothelium showed a decrease in cell density similar to that after conventional full-thickness penetrating keratoplasty.
Aged↗
A technique to excise the descemet membrane from a recipient cornea (descemetorhexis).
OBJECTIVE: To describe a technique for excision of the Descemet membrane (DM) from the recipient eye for preparation of a recipient stromal bed in posterior lamellar keratoplasty. METHODS: In 10 human eye bank eyes and 3 patients, recipient eyes had a 5.0-mm scleral tunnel incision made extending 1.0 mm into the peripheral cornea at the 12 o'clock surgical position. The anterior chamber was completely filled with air, and a reflective glide was placed through the incision onto the iris, to better visualize DM. A 9.0-mm mark was made onto the corneal epithelium to outline the area from which the Descemet membrane was to be removed. With a custom-made scraper, the DM was then carefully stripped off the posterior stroma by loosening the membrane at the 6 o'clock position and pulling it toward the incision at 12 o'clock. The excised DMs were evaluated by light and electron microscopy. RESULTS: In all recipient eyes, DM could be easily and completely removed from the posterior corneal stroma. Microscopy showed isolated DMs without stromal tissue elements. CONCLUSION: With the technique described, DM can be excised in a controlled fashion without damaging the posterior corneal stroma, to quickly create a recipient stromal bed before implantation of a donor posterior lamellar disk in posterior lamellar keratoplasty.
Corneal Stroma↗
Trypan blue staining in vitreoretinal surgery.
PURPOSE: To evaluate the efficacy of trypan blue for staining the internal limiting membrane (ILM) and epiretinal membranes (ERM) in vitreoretinal surgery. DESIGN: Prospective noncomparative case series. PARTICIPANTS: Fifty eyes of 50 patients with macular pucker (n = 22), macular hole (n = 18), or a combination (n = 2), proliferative vitreoretinopathy (n = 5), or diabetic retinopathy (n = 3). METHODS: Trypan blue 0.2% was used to stain the ILM or ERM during vitreoretinal surgery. MAIN OUTCOME MEASURES: The intraoperative visibility of the membranes was scored as poor, moderate, good, or excellent. RESULTS: The application of trypan blue onto the ILM or the ERM resulted in a useful bluish staining, facilitating the identification, delineation, and removal of the membranes in all surgeries. No residual staining or adverse effects related to the dye were observed. CONCLUSIONS: Trypan blue stains both ILM and ERM and might be an useful tool in vitreoretinal surgery.
Adult↗
Trypan blue staining of epiretinal membranes in proliferative vitreoretinopathy.
OBJECTIVE: To determine whether trypan blue staining facilitates epiretinal membrane (ERM) removal in proliferative vitreoretinopathy. METHODS: In 10 patients undergoing vitrectomy for proliferative vitreoretinopathy, ERM peeling was performed without staining the tissue, until no additional ERMs were clearly visible. Then, after a fluid-air exchange, 0.06% trypan blue solution was applied onto the retinal surface. After 1 minute, all excess dye was removed and, after an air-fluid exchange, ERM peeling was completed. Excised ERM specimens were analyzed by transmission electron microscopy. MAIN OUTCOME MEASURES: For each patient, the efficacy of trypan blue staining of ERMs during surgery was scored. RESULTS: In all patients, intraoperative staining of ERMs with trypan blue was found to be a useful adjunct, since the dye consistently improved direct visualization and delineation of ERMs and facilitated ERM removal. A clear contrast was created between the stained ERMs and the nonstaining, underlying retina. Electron microscopy showed that only ERM tissue was removed. No adverse reactions related to the use of the dye were observed up to 3 months after surgery. CONCLUSIONS: Trypan blue may be an important new tool in the surgical management of proliferative vitreoretinopathy, since it may allow a more complete and safer ERM removal.
Aged↗
Trypan blue capsular staining to "find" the leading edge of a "lost" capsulorhexis.
PURPOSE: To describe an effective surgical technique to visualize an obscured leading edge of a capsulorhexis. DESIGN: Prospective, interventional case series. METHODS: In six eyes of six patients in which the capsulorhexis was started but could no longer be seen during surgery, the anterior chamber was irrigated to remove all viscoelastic, and 0.3-ml trypan blue 0.06% was applied onto the anterior lens capsule to stain and visualize the leading edge of the capsulorhexis. RESULTS: In all patients, the leading edge of the capsulorhexis was quickly visualized by using the dye. No adverse reactions were observed up to 1 year after surgery. CONCLUSION: Trypan blue staining of the anterior lens capsule is an effective and apparently safe technique to "find" a "lost" capsulorhexis during surgery.
Capsulorhexis↗
Corneal endothelial cell density after trypan blue capsule staining in cataract surgery.
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Aged↗
Trypan-blue-stained viscoelastic material for ophthalmic surgery.
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Coloring Agents↗
Sutureless, posterior lamellar keratoplasty: a case report of a modified technique.
PURPOSE: To describe a technique for sutureless, posterior lamellar keratoplasty. METHODS: The procedure was performed for a case of pseudophakic bullous keratopathy. Through a 5.0-mm, self-sealing scleral tunnel incision, a stromal pocket was dissected across the cornea, just above Descemet's membrane. An 8.5-mm diameter posterior lamellar disc, consisting of posterior stroma, Descemet's membrane, and endothelium, was transplanted without suture fixation. RESULTS: One week after surgery, the best spectacle corrected visual acuity (BSCVA) was 0.8 (20/25), with S -1.5 and C -1.0 x 85 degrees. After 1 year, the posterior transplant was clear and in position, and the BSCVA was 0.8 with S -1.5 and C -1.75 x 80 degrees. Pachymetry measured 0.60 mm. Endothelial cell counts averaged 1390 cells/mm2. CONCLUSION: Sutureless, posterior lamellar keratoplasty may be an effective new surgical approach for managing corneal endothelial disorders.
Corneal Diseases↗
Transplantation of Descemet's membrane carrying viable endothelium through a small scleral incision.
PURPOSE: To design a technique for transplantation of the Descemet's membrane (DM) as a carrier for its endothelium, while maintaining the low-astigmatic recipient anterior corneal curvature. METHODS: In a human eye bank eye model, recipient eyes (n = 15) had a 5.0-mm scleral tunnel incision made, extending 1.0 mm into the peripheral cornea. A 9.0-mm-diameter Descemeto rhexis was created, i.e., a circular portion of DM was stripped from the posterior stroma. With use of a custom-made inserter, a 9.0-mm-diameter donor DM carrying autologous donor endothelium was brought into the anterior chamber and positioned against the recipient posterior stroma. The procedure was evaluated by keratometry, endothelial vital and supravital staining, and light microscopy. RESULTS: Mean postoperative astigmatism was 1.0 D (+/-0.6 D). Implanted donor DM showed an intact endothelial cell layer, with 3.4% (+/-1.1%) dispersed focal cell death. Microscopy showed normal endothelial cell morphology and complete apposition of the donor DM against the recipient posterior stroma. CONCLUSIONS: DM can be transplanted in vitro with acceptable damage to the donor endothelium and with little induced astigmatism.
Cell Survival↗
New techniques in lamellar keratoplasty.
In the past years, several lamellar keratoplasty surgical techniques have been developed, modified or improved in the past years, including microkeratome assisted anterior and posterior lamellar keratoplasty, anterior lamellar keratoplasty using air-dissection or visco-dissection, sutureless posterior lamellar keratoplasty, LASIK for postkeratoplasty astigmatism, and excimer laser assisted keratophakia for keratoconus or to manage complications after LASIK. These procedures may continue to gain interest as alternative procedures for a penetrating keratoplasty in the treatment of various corneal disorders.
Corneal Transplantation↗
Posterior lamellar keratoplasty.
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Corneal Transplantation↗