Spontaneous Descemet Membrane Detachment After Penetrating Keratoplasty-Clinical Presentation and Outcome of Air/Gas Descemetopexy.

PURPOSE: To describe the clinical characteristics and treatment of spontaneous Descemet membrane (DM) detachment occurring decades after penetrating keratoplasty (PK). METHODS: A multicenter interventional case series design was used. We reviewed the medical records of 4 patients with a history of PK presenting with spontaneous DM detachment at 3 university hospitals in Israel and an ocular surgery institute in The Netherlands in 2016 to 2019. Patient demographic and clinical data, postoperative best corrected visual acuity, findings on preoperative and postoperative anterior segment optical coherence tomography (AS-OCT), and graft survival were recorded. RESULTS: Patients were aged 46 to 50 years. All had undergone PK for keratoconus 20 to 26 years previously. Patients presented within 18 to 180 days of onset of visual disturbance. Symptoms included sudden painless visual loss (2 patients), gradual visual loss and foreign body sensation (1 patients), and visual loss not otherwise specified (1 patient). Slit-lamp examination showed corneal edema, and AS-OCT showed DM detachment of variable extent. In 2 patients, the initial diagnosis was graft rejection and failure. Treatment consisted of anterior chamber injection of air (n = 3) or 20% SF6 (n = 1). In 3 patients, the DM reattached and the cornea regained its clarity. The fourth patient had persistent DM detachment that required repeated PK. CONCLUSIONS: Spontaneous DM detachment can mimic late graft failure in patients after PK. If diagnosed early, DM reattachment may be performed by air/gas injection, avoiding repeated keratoplasty. Eyes with presumed late penetrating graft rejection or failure should be examined by AS-OCT to exclude DM detachment.

Spontaneous reattachment of Descemet membrane detachment after deep anterior lamellar keratoplasty: A case report.

RATIONALE: To report a case of late spontaneous reattachment of Descemet membrane (DM) detachment after deep anterior lamellar keratoplasty (DALK). PATIENT CONCERNS: A 50-year-old woman with stromal corneal scarring underwent a DALK with the big bubble technique. The DM detachment and double anterior chamber were observed on the first day after operation. DIAGNOSES: Descemet membrane detachment after deep anterior lamellar keratoplasty [Oculus Dexter (OD), indicates right eye]. INTERVENTIONS: Sterile air injection was unsuccessful. Conservative observation was performed. OUTCOMES: During the follow-up, the donor cornea kept transparent and no edema was observed. The DM reattached spontaneously at the fifth months post-DALK. LESSONS: The present case suggests that the retained host DM may result in DM detachment after DALK. For the DM detachment without roll rim, the detachment may spontaneously reattach in several months after surgery.

Efficacy and safety of Descemet's membrane endothelial keratoplasty versus Descemet's stripping endothelial keratoplasty: A systematic review and meta-analysis.

PURPOSE: Based on current evidence, the efficiency and safety of Descemet's membrane endothelial keratoplasty (DMEK) was compared with that of Descemet's stripping endothelial keratoplasty (DSEK). METHODS: Pubmed, Embase, Web of Science, the Cochrane Database and conference abstracts were comprehensively searched for studies that compared the efficacy and safety of DMEK and DSEK. The efficacy outcome was the postoperative best-corrected visual acuity (BCVA). The safety outcomes included the postoperative endothelial cell density (ECD) and complications such as graft detachment, graft rejection, graft failure, postoperative elevated intraocular pressure (IOP), tissue loss, etc. The outcomes were pooled using random-effects models with Stata 13.0 software. Heterogeneity was qualified with Q statistic and I2/H2 statistic. Publication bias was assessed using funnel plot, Begg rank correlation test, and Egger or Horbard linear regression. RESULTS: 19 articles were eligible, and 1124 eyes and 1254 eyes were included in the DMEK and DSEK groups, respectively. The overall pooled estimates showed a significantly better postoperative BCVA, a comparable ECD and an increased graft detachment rate in the DMEK group compared with the DSEK group (BCVA: mean difference (MD) = -0.15, 95% CI = -0.19 to -0.11, P<0.001; ECD: MD = 14.88, 95% CI = -181.50 to 211.27, P = 0.882; graft detachment rate: OR = 4.56, 95% CI = 2.43 to 8.58, P<0.001). Except for the postoperative ECD, which was changed to be higher in the DSEK group than the DMEK group, the learning curve did not have a marked effect on the comparison outcome of the BCVA and graft detachment rate based on the estimates pooled from studies that collected data during the DMEK learning phase (ECD (learning curve): MD = -361.24, 95% CI = -649.42 to -73.07, P = 0.014). CONCLUSION: Although DMEK is a more technically difficult and challenging procedure, it may represent a safe and more efficient alternative to DSEK for the treatment of corneal endothelial diseases, even during its learning curve.

[Critical endothelial procedures during posterior lamellar graft preparation and transplantation]. / Endothelkritische Prozeduren während der Herstellung und Transplantation posteriorer lamellärer Hornhauttransplantate.

BACKGROUND: In view of the very low proliferation rate and functional importance of the corneal endothelium in maintaining corneal transparency, safeguarding the integrity of this monolayer plays a central role in posterior lamellar corneal transplantation. Several critical endothelial procedural stages are necessary to carry out such a transplantation. OBJECTIVE: This article presents various preparatory and operative approaches for carrying out the necessary and critical stages within the framework of posterior lamellar corneal transplantation and concentrates on the question of optimization. METHODS: A review of our own studies and studies of other groups is presented. RESULTS: For the performance of critical endothelial procedural steps, a variety of approaches are available. These range from preparation and insertion of the transplant, through the manipulation during centralization up to the effects of postoperative air or gas bubble tamponade. CONCLUSION: Because endothelial damage can permanently impair the integrity of lamellar transplants, a minimal handling and no touch policy should be strived for in all critical procedures. Long-term data on the follow-up course will show which of the procedures favored by various authors lead to the best postoperative results.

Biomechanical relationships between the corneal endothelium and Descemet's membrane.

The posterior face of the cornea consists of the corneal endothelium, a monolayer of cuboidal cells that secrete and attach to Descemet's membrane, an exaggerated basement membrane. Dysfunction of the endothelium compromises the barrier and pump functions of this layer that maintain corneal deturgesence. A large number of corneal endothelial dystrophies feature irregularities in Descemet's membrane, suggesting that cells create and respond to the biophysical signals offered by their underlying matrix. This review provides an overview of the bidirectional relationship between Descemet's membrane and the corneal endothelium. Several experimental methods have characterized a richly topographic and compliant biophysical microenvironment presented by the posterior surface of Descemet's membrane, as well as the ultrastructure and composition of the membrane as it builds during a lifetime. We highlight the signaling pathways involved in the mechanotransduction of biophysical cues that influence cell behavior. We present the specific example of Fuchs' corneal endothelial dystrophy as a condition in which a dysregulated Descemet's membrane may influence the progression of disease. Finally, we discuss some disease models and regenerative strategies that may facilitate improved treatments for corneal dystrophies.

The Ultrastructures and Mechanical Properties of the Descement's Membrane in Fuchs Endothelial Corneal Dystrophy.

Fuchs endothelial corneal dystrophy (FECD), is the most common corneal endothelial dystrophy, and contributes up to 50% of all corneal transplantations performed in developed countries. FECD develops in Descemet's membrane (DM) and possibly alters the mechanical properties and internal structures in this basal lamina. In this work, the morphology and mechanical properties of FECD-DMs are studied by transmission electron microscopy (TEM) and quantitative dynamic atomic force microscopy (QD-AFM) at nano scale. Pathological wide-space collagens that are typical of FECD display different mechanical properties in that they are softer than the remaining tissue both for dehydrated- and fully hydrated samples. Additionally, the hydration level has major influence on the mechanical properties. These findings could help to further understand the structural changes in FECD, and possibly be useful for further characterization of the disease, the diagnosis and assessment or even pathologic analysis.

Tubulaciones retiniana externas / Outer Retinal tubulations

No disponible

Effects of graft thickness and asymmetry on visual gain and aberrations after descemet stripping automated endothelial keratoplasty.

IMPORTANCE: Understanding the contribution of graft thickness and asymmetry to visual gain and posterior corneal (PC) higher-order aberrations (HOAs) may assist optimizing visual outcomes after Descemet stripping automated endothelial keratoplasty (DSAEK). OBJECTIVE: To investigate the effects of graft thickness and asymmetry on visual gain and aberrations after DSAEK. DESIGN: Retrospective analysis of an interventional case series of eyes undergoing DSAEK. Visual gain was defined as the difference between preoperative and 6-month postoperative best-corrected visual acuity in logMAR equivalents. Graft thickness was measured by anterior-segment optical coherence tomography. Corneal topography and HOAs were measured by Scheimpflug imaging. Raw posterior corneal (PC) elevation data were exported and fitted against a best-fitted sphere, providing a measure of donor lenticule asymmetry. Correlation analysis was performed among visual gain, graft thickness, graft asymmetry, and PC HOAs. SETTING: University Eye Clinic Maastricht. PARTICIPANTS: Seventy-nine eyes with corneal endothelial dysfunction. EXPOSURE: All patients underwent DSAEK [corrected]. MAIN OUTCOMES AND MEASURES: Visual gain, graft thickness, graft asymmetry, and PC HOAs. RESULTS: Mean best-corrected visual acuity improved from 0.63 logMAR equivalents preoperatively to 0.25 logMAR equivalents postoperatively (P < .001). Mean (SD) graft thickness of the series was 97 (25) (range, 39-145) µm. After excluding patients with vision-limiting comorbidities, visual gain significantly correlated with graft thickness (r = -0.35 [P = .02]). This correlation was strongest in patients with pseudophakic bullous keratopathy (r = -0.62 [P = .01]). Graft thickness significantly correlated with graft asymmetry in the 4- and 6-mm zones (r = 0.32 [P = .007] and r = 0.32 [P = .006], respectively), which in turn correlated with all but spherical PC HOAs. CONCLUSIONS AND RELEVANCE: After DSAEK, visual gain shows a significant correlation with graft thickness in patients without vision-limiting comorbidities. This relationship is strongest in patients with pseudophakic bullous keratopathy. Graft thickness also correlates with graft asymmetry, which in turn correlates with all but spherical PC HOAs. These findings may assist surgeons in choosing DSAEK graft thickness and shape, particularly in eyes without vision-limiting comorbidities. Further randomized trials are needed to investigate the relationship between graft thickness and visual gain after DSAEK.

A fluid mechanical explanation of the spontaneous reattachment of a previously detached Descemet membrane.

Descemet membrane detachment (DMD) is a rare but potentially serious surgical complication that arises most often during cataract surgery. A recent study (Couch, S. M. & Baratz, K. H. (2009) Cornea, 28, 1160-1163) cited the case of a patient with DMDs in both eyes, noting that though one detachment was surgically repaired, the other spontaneously reattached and needed no further treatment. A fluid mechanical model of buoyancy-driven aqueous humour flow in the anterior chamber around a DMD is developed to explain this phenomenon. The analytical model is based on the lubrication theory limit of the Navier-Stokes equations. The flow is determined for a fixed geometry and the possible motion of the DMD is then analysed. Numerical calculations are also carried out (using COMSOL© Multiphysics) to confirm the lubrication theory results. The analytical and numerical results both show that, under the correct conditions, either spontaneous reattachment or worsening of the tear may occur. We conclude that it is possible that clinical outcomes for DMDs may be controlled by adjusting the temperature difference across the eye and/or the orientation of the patient.

Descemet's stripping endothelial automated keratoplasty using Tan EndoGlide endothelium insertion system.

PURPOSE: The purpose of this study was to evaluate early visual and refractive outcomes of Descemet's stripping endothelial keratoplasty (DSAEK). METHOD: Nine eyes of 7 male and 2 female patients, mean age 73 years, were treated with DSAEK. Eight had pseudophakic bullous keratopathy and 1 had advanced Fuch's syndrome. Patients were followed up for a mean of 11.4 months (range, 4-26). The DSAEK technique consisted of stripping Descemet's membrane and endothelium from a recipient cornea and transplanting the posterior stroma and endothelium of a donor cornea using the Tan EndoGlide. The mean operating time was 61.89 minutes (standard deviation [SD], 9.3). RESULTS: The median donor diameter was 8.375 mm (range, 8.25-8.75) and the mean donor thickness was 114.4 µm (range, 98-129). Mean preoperative sphere was -2.41 that changed postoperatively in -1.21. Mean endothelial cell loss was 25% (range, 23%-45%) at 6 months after surgery. Corneal pachymetry was reduced from 796.6 µm preoperatively to 535.5 µm postoperatively. Best corrected vicual acuity (BCVA) was 20/40 or better postoperatively and exceeded the preoperative BCVA in all eyes. No graft failure was present. Two partial graft dislocations (1st and 5th postoperative day) were observed. One graft was successfully attached after reinjecting an air bubble (rebubbling) in the anterior chamber and the other graft was reattached with 4 10/0 nylon sutures after failed rebubbling. CONCLUSIONS: The key to successful endothelial transplantation is the protection and preservation of as many donor endothelial cells as possible. The TAN EndoGlide is a device that consistently delivers a donor lenticule through a small incision with minimal endothelial loss, while making the insertion procedure relatively reliable and consistent, with the surgeon in full control of the donor at all stages of insertion. The endothelial cell loss during this technique is comparable (if not better) with other endothelial graft insertions systems.

Spontaneous resolution of extensive descemet membrane detachment caused by sodium cyanide injury to the eye.

PURPOSE: To describe the clinical course, ultrasonographic and confocal microscopic findings in a patient who developed a large Descemet membrane (DM) detachment that resolved spontaneously after ocular sodium cyanide injury. METHODS: Case report. RESULTS: The patient presented with severe corneal stroma edema, a large detachment of DM, iritis, and anterior subcapsular lens opacity in the left eye caused by contact with 5% sodium cyanide. The ultrasound biomicroscopic and in vivo confocal microscopic examination exhibited the configuration of the DM detachment and extensive damage of corneal cells. Although no viable endothelial cells were observed with in vivo confocal microscopy, the DM spontaneously reattached 11 days after injury, coincident with increased intraocular pressure. However, persistent corneal edema and iris atrophy were observed 6 months after DM reattached. CONCLUSIONS: Sodium cyanide can cause severe injuries to the cornea and the anterior segment. Extensive DM detachment may resolve spontaneously despite the absence of viable endothelial cells.

Rupture pressure of the posterior lamella obtained during big-bubble deep anterior lamellar keratoplasty.

PURPOSE: To investigate the pressure required to rupture the posterior lamella obtained during the presumed Descemet membrane-baring big-bubble technique of deep anterior lamellar keratoplasty (DALK). METHODS: DALK using the big-bubble technique was carried out on donor corneoscleral discs mounted on an artificial anterior chamber. Once the anterior lamella was removed, the chamber was connected to a mercury manometer. The pressure inside the chamber was increased until rupture occurred or the manometer reached its measurement limit. RESULTS: The deep lamella ruptured at 252 mm Hg in one cornea, at 270 mm Hg in another, and had not ruptured at 300 mm Hg (upper limit of the manometer) in the remaining 18 donor corneas. CONCLUSIONS: The posterior lamella of big-bubble DALK probably confers significant structural integrity on the globe.

Agudeza visual y densidad de células endoteliales tras queratoplastia endotelial de membrana de Descemet (DMEK) / Visual acuity and endothelial cell density following Descemet membrane endothelial keratoplasty (dmek)

Objetivo: Evaluación de los resultados visuales y de la densidad de células endoteliales en los 120 primeros ojos sometidos a queratoplastia endotelial de membrana de Descemet (DMEK) como tratamiento para la distrofia endotelial de Fuchs. Material y métodos: Se evaluaron los primeros 120 ojos sometidos a DMEK. En todos ellos se midió la agudeza visual mejor corregida (AVMC) antes y al 1, 3 y 6 meses después de la cirugía, así como la densidad celular endotelial (DCE) antes y a los 6 meses. Resultados: En los ojos con trasplante exitoso y sin patologías concomitantes (n=96), se observo una AVMC en el 77% de los casos al mes de la cirugía, en el 92% a los 3 meses y en el 95% a los 6 meses. La AVMC fue mayor o igual 0,8 en el 50%, 63% y 73% de los casos y mayor o igual 1,0 en el 23%, 34% y 45% al 1, 3 y 6 meses después de la cirugía, respectivamente. La DCE preoperatoria fue 2.610 (más menos,185) células/mm2 y 1.770 (más menos, 520) células/mm2 a los 6 meses postcirugía. En quince ojos se realizó una queratoplastia endotelial con pelado de la membrana de Descemet (DSEK) secundaria. En este grupo, el 91% de los pacientes alcanzó una AVMC mayor o igual 0,5, alcanzando solo uno de ellos una AVMC de 0,8 (n=11) a los 6 meses. Además, la DCE media fue de 2.580 (más menos, 185) células/mm2 antes y de 1.310 (más menos, 740) células/mm2 a los 6 meses de la operación (n=13). Conclusiones: DMEK permite una rápida y casi completa rehabilitación visual. La DCE postoperatoria observada es comparable al obtenido con técnicas precedentes de queratoplastia endotelial(AU)

Purpose: To assess the clinical outcomes of DMEK in the first series of 120 eyes operated for the treatment of Fuchs endothelial dystrophy in terms of visual acuity and endothelial cell density. Methods: The first 120 consecutive eyes that underwent DMEK (i.e. transplantation of an isolated donor Descemet membrane with its endothelium) were evaluated. In all eyes, the best corrected visual acuity (BCVA) before and at 1, 3 and 6 months after surgery, as well as the endothelial cell density (ECD) before and at 6 months were measured. Results: In eyes with a functional DMEK graft and good visual potential (n=96), the BCVA was major or equal 20/40 (major or equal 0.5) in 77% after 1 month, 92% after 3 months, and 95% after six months; major or equal 20/25 (major or equal 0.8) in 50%, 63%, and 73% of the cases, and major or equal 20/20 (major or equal 1.0) in 23%, 34%, and 45% of the cases at 1, 3, and 6 months respectively. In this group, ECD averaged 2610 (more less 185) cells/mm2 before, and 1770 (more less 520) cells/mm2 at six months after surgery (n=96). In 15 eyes, a secondary Descemet stripping endothelial keratoplasty (DSEK) was performed. In this group, 91% of patients reached a BCVA of major or equal 20/40 (major or equal 0.5) and only one patient achieved a BCVA of 0.8 at 6 months after surgery (n=11). Furthermore, ECD averaged 2580 (more less 185) cells/mm2 before and 1310 (more less 740) cells/mm2 at six months (n=13). Conclusion: DMEK provides a fast and high visual rehabilitation. Endothelial cell density loss may be similar to earlier types of endothelial keratoplasty(AU)

Descemet's membrane automated endothelial keratoplasty (DMAEK): visual outcomes and visual quality.

BACKGROUND/AIMS: To determine whether the stromal rim that carries the bare endothelial graft in Descemet's membrane automated endothelial keratoplasty (DMAEK) has any effect on final visual outcome or visual quality. METHODS: Twenty-four DMAEK eyes and 22 Descemet's membrane endothelial keratoplasty (DMEK) eyes (with no stromal rim) were evaluated for corrected distance acuity, full-field Humphrey visual field (VF) 120-2 and pupil size. The inner and outer diameter of the DMAEK stromal ring was measured from slit lamp photos. Patients completed a questionnaire rating postoperative symptoms and visual complaints. Exclusion criteria were pre-existing glaucoma, retinal pathology or inability to return for postoperative examinations. RESULTS: Median Snellen acuities were comparable between DMAEK and DMEK groups: 20/25 and 20/20-3, respectively. The mean central opening of the DMAEK stromal ring was 5.6 × 5.5 (range 3.8-6.9) mm. The incidence of VF defects, visual complaints of glare, halos, light sensitivity and night driving difficulties was comparable between groups (all p > 0.1). A larger scotopic pupil size (< 5.5 mm) was not associated with increased incidence of VF defects in either group (p = 0.3). CONCLUSIONS: Surprisingly, compared with uniformly thin DMEK grafts, DMAEK grafts with a stromal rim had no increase in VF defects or visual complaints.

Bilateral Descemet membrane detachment after canaloplasty.

We report a case of bilateral Descemet membrane detachment (DMD) after canaloplasty in a 70-year-old Portuguese man with primary open-angle glaucoma. The patient developed bilateral DMD immediately following consecutive (1 week apart) canaloplasty surgery in both eyes. Slitlamp biomicroscopy, gonioscopy, and Fourier-domain optical coherence tomography (FD-OCT) findings are described. On postoperative day 1, in both cases, slitlamp biomicroscopy revealed an unscrolled inferonasal DMD and a clear cornea with deep and quiet anterior chambers. Gonioscopy showed an intact, lightly pigmented, and distended trabecular meshwork with no evidence of suture extrusion. High-resolution FD-OCT revealed a widely dilated canal of Schlemm, trabecular distention, and a retrocorneal hyperreflective membrane corresponding to a DMD. At 3 months, the DMD resolved spontaneously in both eyes. Although DMD is a known complication of canaloplasty, the occurrence of bilateral symmetrically located DMDs in our case suggests a possible anatomical predisposition in addition to factors induced by the surgical technique.

Spontaneous resolution of Descemet membrane detachment following big-bubble deep anterior lamellar keratoplasty.

PURPOSE: To report 2 cases of delayed spontaneous Descemet membrane (DM) reattachment following big-bubble deep anterior lamellar keratoplasty (DALK). METHODS: A 21-year-old man with keratoconus and a 36-year-old woman with corneal macular dystrophy underwent big-bubble DALK. No injury to DM was noted intraoperatively or postoperatively. Postoperatively, the patients developed central DM detachment with double anterior chamber formation. A nonsurgical conservative approach (waiting technique) was adopted. RESULTS: Three weeks postoperatively, the double anterior chamber resolved spontaneously with complete DM reattachment and a clear donor cornea. CONCLUSIONS: DM detachment and double anterior chamber following big-bubble DALK may resolve spontaneously.

Endothelial keratoplasty: DSEK/DSAEK or DMEK--the thinner the better?

PURPOSE OF REVIEW: Endothelial keratoplasty has been adopted worldwide as an alternative to penetrating keratoplasty in the treatment of corneal endothelial disorders. Descemet stripping (automated) endothelial keratoplasty (DSEK/DSAEK) may be the current standard, whereas Descemet membrane endothelial keratoplasty (DMEK), that is, isolated transplantation of Descemet membrane, may allow further improvement of clinical outcome. RECENT FINDINGS: DSEK/DSAEK may still have three major challenges: suboptimal visual acuity and relatively slow visual rehabilitation, limited accessibility due to required investments in equipment or the purchase of predissected tissue, and a drop in donor endothelial cell density in the early postoperative phase. Although DMEK may allow much quicker and (near) complete visual rehabilitation as well as easier logistics in donor preparation, the surgical technique may initially require more training to obtain consistent outcomes. SUMMARY: Compared with DSEK/DSAEK, DMEK may have higher clinical potential with 75% of cases reaching 20/25 or better (> or =0.8) within 1-3 months. Furthermore, preparation of isolated Descemet grafts does not require large investments and may increase overall donor tissue availability. Hence, corneal surgeons may consider 'to make the switch' from DSEK/DSAEK to DMEK.

Corneal hysteresis following descemetorhexis with endokeratoplasty: early results.

The corneal biomechanical properties following descemetorhexis with endokeratoplasty (DXEK) and in normal subjects were studied in 100 eyes (12 DXEK and 88 age-matched normal subjects). Corneal hysteresis measurements were significantly lower in DXEK vs normal subjects. DXEK has a direct effect on corneal hysteresis and corneal biomechanical properties of the human cornea.