Descemet membrane detachment after trabeculectomy

Descemet's membrane detachment (DMD) can be a potentially serious complication of intraocular surgery or ocular trauma. The cause is not very clear. We are trying to remind an awareness of the spectrum of DMD resulting from trabeculectomy by presenting a case of extensive DMD after trabeculectomy which was successfully repaired.

Preparation, preservation, and morphological evaluation of the donor graft for descemet membrane endothelial keratoplasty： an experimental study

Background Though there have been various methods for harvesting and preserving descemet membrane （DM） and intact endothelium,there is no literature about the morphological evaluation of endothelium after graft preparation for descemet membrane endothelial keratoplasty （DMEK）.The aim of this study was to establish and improve a simple method for preparing,preserving,and morphologically evaluating the donor graft for DMEK.Methods To obtain a donor graft,an air bubble was formed by injecting a 29 G needle with 1 ml sterile air into a small edge created outside the Schwalbe line.Another needle was inserted into the bubble through the stroma to aspirate the air or replace half the air with organ culture medium.Trypan blue was used to mark the location for small incision to improve the success rate.Frozen sections were stained with hematoxylin and eosin （HE）.Based on the air bubble,DM grafts were divided into four groups：group A （normal control）,graft without any operative technique; group B,graft with zero-pressure air bubble; group C,graft with full-pressure air bubble; group D,graft with half-pressure air bubble.The four groups of grafts were preserved for 24 hours to observe the effect of bubbles on cells.The gross and ultrastructure morphologies were evaluated using alizarin red and scanning electron microscopy （SEM）,respectively.Results Donor grafts were harvested via the air bubble technique,facilitated by prior trypan blue staining.HE-stained sections revealed a pure graft without stroma.There were no significant changes under light microscope.In group A,SEM revealed a confluent layer of polygonal endothelium with distributed microvilli exhibiting characteristics of interdigitating junctions.In group B,intercellular borders became thinner.In group C,interdigitations were almost flat and microvilli were observed less frequently.In group D,other than less microvilli,there were minimal changes.Conclusions The donor graft preparation method appears to be effective and convenient.Properly decreasing the air pressure could protect and preserve the endothelium.

Ultrathin Descemet stripping automated endothelial keratoplasty versus Descemet membrane endothelial keratoplasty:a fellow-eye comparison

Background:To compare the visual outcome and patients’satisfaction after ultrathin Descemet stripping automated endothelial keratoplasty(UT-DSAEK)and Descemet membrane endothelial keratoplasty(DMEK)performed on fellow eyes of the same patients.Methods:In this retrospective study,the records of 18 pseudophakic patients affected by Fuchs endothelial dystrophy who underwent DMEK in one eye and UT-DSAEK in the fellow eye were reviewed.Best corrected visual acuity(BCVA),corneal pachymetry,keratometry,corneal aberrations,photopic and mesopic contrast sensitivity,and endothelial cell counts measured 12 months after surgery in either eye were analyzed and compared.The results of a satisfaction questionnaire were also reviewed.Results:Twelve months after surgery,BCVA was not significantly different in UT-DSAEK and DMEK eyes(0.10±0.04 and 0.07±0.07 logMAR,respectively);at both 4-and 6 mm optical zones total and posterior corneal higher order aberrations(HOAs),posterior astigmatism and total coma were significantly lower after DMEK;BCVA in both groups was significantly correlated mainly with anterior corneal aberrations;contrast sensitivity was higher after DMEK especially in mesopic conditions and at medium spatial frequencies;the endothelial cell density was similar,although slightly higher in the UT-DSAEK group(p=0.10).The satisfaction questionnaire showed that although patients were highly satisfied from both procedures,more than half of them preferred DMEK and reported a more comfortable and quicker postoperative recovery.Conclusions:DMEK and UT-DSAEK showed no evidence of difference in terms of postoperative BCVA,although DMEK had a better performance in terms of contrast sensitivity,posterior corneal aberrations and overall patient satisfaction.

Surgical management of spontaneous,lateonset Descemet membrane detachment after penetrating keratoplasty for keratoconus:a case report

Background:To report a surgical method for treating corneal oedema in a case of late-onset Descemet membrane detachment after penetrating keratoplasty.Case presentation:A 55-year old patient presented with sudden visual loss in his left eye 28 years after penetrating keratoplasty for keratoconus.Slit-lamp biomicroscopy revealed a distortion of the corneal graft anatomy with protrusion of the graft and peripheral thinning and steepening in the residual host tissue,accompanied by corneal graft oedema.Anterior segment optical coherence tomography revealed detachment of Descemet membrane localized to the area of the graft oedema.We proceeded with a full-thickness,partially circumferential incision in the graft-host junction,followed by repositioning and re-suturing of the graft in place,and intracameral air injection in order to achieve reattachment of Descemet membrane.Conclusions:Corneal graft repositioning in combination with re-bubbling may represent an effective therapeutic option in keratoconic patients with peripheral thinning in the residual host corneal tissue and subsequent Descemet membrane detachment.

Descemet＇s membrane detachments post cataract surgery：a management paradigm

Descemet’s membrane detachments （DMD） are relatively common after cataract surgery and most do not require any treatment. However, if large DMD are not treated appropriately, significant visual morbidity can ensue. We aim to develop a guideline for the management of DMD post cataract surgery based on a retrospective review of all cases encountered at the Royal Victorian Eye and Ear Hospital, Melbourne, Australia over a 4-year period from 2010 to 2014. We suggest conservative management if the visual axis is not involved; however, after 3mo surgical intervention may be warranted to prevent corneal sequelae. In cases where the visual axis is involved we suggest early intervention with air tamponade. The main risk factor for irreversible corneal oedema and subsequent endothelial transplant appears to be direct endothelial trauma rather than the DMD itself.

Clinical results of non-Descemet stripping endothelial keratoplasty

AIM： To investigate the impact of non-Descemet stripping endothelial keratoplasty（non-DSEK） on graft rejection rate,and its overall procedural effectiveness in patients.METHODS： Non-DSEK was performed on 65 eyes of 64 patients,and the procedural outcomes,including rejection episodes,failure and dislocation of the grafts,best corrected visual acuity（BCVA）,endothelial cell density（ECD）,and other complications,were analyzed retrospectively.RESULTS： Of the 65 eyes,63 recovered from bullous keratopathy with a clear cornea.The mean follow-up time was 26.4mo（range,6-84mo）.The mean BCVA improved from 1.70 log MAR preoperatively to 0.54 log MAR at 3mo,0.46 logM AR at 6mo,and 0.37 logM AR at 1y after surgery.The postoperative donor ECD of the 25 patients who successfully underwent specular microscopic examination was 1918±534 cells/mm^2（range,637 to 3056 cells/mm^2）,and the mean endothelial cell loss was 41.9% at 24 mo postoperatively.One eye developed secondary glaucoma and required regrafting via penetrating keratoplasty（PKP）.Another eye had postoperative graft failure due to rejection at 26 mo.Postoperative graft dislocation occurred in eight eyes.All of the eight dislocated grafts were reattached using air reinjection.CONCLUSION： Immunological graft rejection of the donor graft rarely occurs in non-DSEK.Therefore,non-DSEK is a safe,concise,and effective alternative to restore corneal decompensation when the Descemet membrane is disease-free.

Incidence of cystoid macular edema after Descemet's stripping automated endothelial keratoplasty

AIM： To determine the incidence of cystoid macular edema（CME） after Descemet＇s stripping automated endothelial keratoplasty（DSAEK）.METHODS： This study included all consecutive patients operated in a Spanish tertiary reference hospital over a period of four years. A total of 55 eyes from 47 patients matched the selection criteria. CME was diagnosed clinically at the slit-lamp and confirmed by optical coherence tomography. RESULTS： Six cases of CME were diagnosed postoperatively, which represented an incidence of 11%. Three patients had previously undergone DSAEK alone（7%; 3/41） and the other three, DSAEK combined with phacoemulsification（21%; 3/14）. Five out of six patients with CME responded to standard therapy.CONCLUSION： CME is a possible complication after DSAEK and can be treated with standard therapy. CME appears more frequently when DSAEK is combined with phacoemulsification and posterior chamber（PC） intraocular lens（IOL） implantation. Intraoperative damage to the corneal endothelial cells might play a role in the pathogenesis of CME. As long as the causes remain unclear, we recommend administering prophylaxis when risk factors are present or when combined surgery is planned.

Effect of the position of the corneal lamella on the frequency of its detachment

AIM:To determine the influence of gaps[places where neither the donor's nor the recipient's Descemet's membrane(DM)is present]and overlaps(places where the recipient's DM is covered by the donor's DM)on the frequency of postoperative detachment of DM endothelial keratoplasty(DMEK)lamellae.METHODS:Totally 64 eyes of 64 patients with Fuchs'endothelial dystrophy or bullous keratopathy indicated for DMEK were randomly divided in two groups.The diameter of the implanted DMEK lamella was the same in both groups(8 mm),but we changed the diameter of the removed recipient DM.In the first group(32 eyes),the circular area was approximately 8.5 mm(gaps);in the second group(32 eyes),the diameter was 7.5 mm(overlaps).Postoperatively we noted all cases of detachment visible on the slit lamp and these cases we indicated for rebubbling.We also measured the uncorrected distance visual acuity(UDVA)as well as corrected distance visual acuity(CDVA)in decimal and postoperative endothelial cell density(ECD).The minimum follow-up time was 6mo.RESULTS:The number of rebubbling procedures in the entire group of patients was 13,i.e.,20.3%,with 6 eyes(18.7%)in the gap group,and 7 eyes(21.9%)in the overlap group.Lamella replacement(re-DMEK)was required in 3(gap group)and 2 patients(overlap group),respectively.The dif ference between the groups was statistically insignificant.The UDVA was 0.54±0.21 in the gap group and 0.58±0.24 in the overlap group.The CDVA was 0.74±0.22 and 0.80±0.16,respectively.ECD was 1920±491 and 2149±570 cells/mm2.The small differences between both groups were not statistically significant.CONCLUSION:We do not notice any difference in the group of patients with overlaps or gaps of DM.The presence of small areas of gaps or overlaps does not affect the frequency of detachment of the DMEK lamellae.

Transplanting embryonic stem cells onto damaged human corneal endothelium

AIM To investigate whether human embryonic stem cells(hESCs) could be made to attach, grow and differentiate on a human Descemet's membrane(DM).METHODS Spontaneously differentiated hESCs were transferred onto a human corneal button with the endothelial layer removed using ocular sticks. The cells were cultured on a DM for up to 15 d. The genetically engineered hESC line expressed green fluorescent protein, which facilitated identification during the culture experiments, tissue preparation, and analysis. To detect any differentiation into human corneal endothelial-like cells, we analysed the transplanted cells by immunohistochemistry using specific antibodies.RESULTS We found transplanted cells form a single layer of cells with a hexagonal shape in the periphery of the DM. The majority of the cells were negative for octamer-binding transcription factor 4 but positive for paired box 6 protein, sodium potassium adenosine triphosphatase(NaKATPase), and Zona Occludens protein 1. In four of the 18 trials, the transplanted cells were found to express CK3, which indicates that the stem cells differentiated into corneal epithelial cells in these cases. CONCLUSION It is possible to get cells originating from hESCs to become established on a human DM, where they grow and differentiate into corneal endothelial-like cells in vitro.

Automated diagnosis and staging of Fuchs’endothelial cell corneal dystrophy using deep learning

Background:To describe the diagnostic performance of a deep learning algorithm in discriminating early-stage Fuchs’endothelial corneal dystrophy(FECD)without clinically evident corneal edema from healthy and late-stage FECD eyes using high-definition optical coherence tomography(HD-OCT).Methods:In this observational case-control study,104 eyes(53 FECD eyes and 51 healthy controls)received HDOCT imaging(Envisu R2210,Bioptigen,Buffalo Grove,IL,USA)using a 6 mm radial scan pattern centered on the corneal vertex.FECD was clinically categorized into early(without corneal edema)and late-stage(with corneal edema).A total of 18,720 anterior segment optical coherence tomography(AS-OCT)images(9180 healthy;5400 early-stage FECD;4140 late-stage FECD)of 104 eyes(81 patients)were used to develop and validate a deep learning classification network to differentiate early-stage FECD eyes from healthy eyes and those with clinical edema.Using 5-fold cross-validation on the dataset containing 11,340 OCT images(63 eyes),the network was trained with 80%of these images(3420 healthy;3060 early-stage FECD;2700 late-stage FECD),then tested with 20%(720 healthy;720 early-stage FECD;720 late-stage FECD).Thereafter,a final model was trained with the entire dataset consisting the 11,340 images and validated with a remaining 7380 images of unseen AS-OCT scans of 41 eyes(5040 healthy;1620 early-stage FECD 720 late-stage FECD).Visualization of learned features was done,and area under curve(AUC),specificity,and sensitivity of the prediction outputs for healthy,early and late-stage FECD were computed.Results:The final model achieved an AUC of 0.997±0.005 with 91%sensitivity and 97%specificity in detecting early-FECD;an AUC of 0.974±0.005 with a specificity of 92%and a sensitivity up to 100%in detecting late-stage FECD;and an AUC of 0.998±0.001 with a specificity 98%and a sensitivity of 99%in discriminating healthy corneas from all FECD.Conclusion:Deep learning algorithm is an accurate autonomous novel diagnostic tool of FECD with very high sensitivity and specificity that can be used to grade FECD severity with high accuracy.