A new clinico-tomographic classification and management algorithm for Descemet's membrane detachment

Surgical management of complicated Descemet's membrane detachment in corneas without prior endothelial keratoplasty

PURPOSE

To provide insights into morphologic and functional features of eyes with complicated Descemet's membrane detachment (DMD) and report clinical outcomes after surgical intervention.

METHODS

Retrospective study of 18 eyes with complicated DMD between 2010 and 2022. Complicated DMD was defined if any of the following criteria applied: prior penetrating keratoplasty (PKP), corneal thinning, total DMD or persistent DMD after Air/Gas-Descemetopexy. Causes, surgical management, and clinical outcomes were analyzed. Scheimpflug tomography, anterior segment optical coherence tomography (AS-OCT) and histologic examination were performed to characterize corneas with DMD.

RESULTS

Fourteen eyes with prior PKP developed spontaneous DMD after 24.2 ± 12.9 years (range = 18 months - 47 years, median = 25.7 years). Complicated DMD without prior PKP was associated in three eyes after cataract surgery and in one eye after infectious keratitis. In cases with previous PKP, AS-OCT demonstrated rupture of Descemet's membrane (DM) in five eyes and spontaneous reattachment was found in four eyes within 8 weeks of initial diagnosis, with no rupture of DM in any of the cases. There was no rupture of DM in corneas without previous PKP. After prior keratoplasty, definitive surgical treatment was repeat PKP in 13 eyes and Air/Gas-Descemetopexy in one eye. In corneas without prior keratoplasty, three eyes underwent PKP and one eye Air/Gas-Descemetopexy. Histological examination of two corneal explants revealed a severely thinned graft-host junction and a disrupted DM close to the graft-host junction. Visual acuity improved from 1.80 ± 0.58 logMAR to 0.75 ± 0.69 logMAR after prior PKP and from 1.45 ± 0.65 logMAR to 0.85 ± 1.13 logMAR without prior PKP. The postoperative course was uneventful in 16 of 18 eyes.

CONCLUSION

PKP is an effective treatment option for complicated DMD, especially in ectatic corneas, whereas Air/Gas-Descemetopexy or Descemet Membrane Endothelial Keratoplasty do not address the primary issue of the curvature anomaly.

The pre-Descemet's layer (Dua's layer, also known as the Dua-Fine layer and the pre-posterior limiting lamina layer): Discovery, characterisation, clinical and surgical applications, and the controversy

The pre-Descemet's layer/Dua's layer, also termed the Dua-Fine layer and the pre-posterior limiting lamina layer, lies anterior to the Descemet's membrane in the cornea, is 10 μm (range 6-16) thick, made predominantly of type I and some type VI collagen with abundant elastin, more than any other layer of the cornea. It has high tensile strength (bursting pressure up to 700 mm of Hg), is impervious to air and almost acellular. At the periphery it demonstrates fenestrations and ramifies to become the core of the trabecular meshwork, with implications for intraocular pressure and glaucoma. It has been demonstrated in some species of animals. The layer has assumed considerable importance in anterior and posterior lamellar corneal transplant surgery by improving our understanding of the behaviour of corneal tissue during these procedures, improved techniques and made the surgery safer with better outcomes. It has led to the innovation of new surgical procedures namely, pre-Descemet's endothelial keratoplasty, suture management of acute hydrops, DALK-triple and Fogla's mini DALK. The discovery and knowledge of the layer has introduced paradigm shifts in our age old concepts of Descemet's membrane detachment, acute corneal hydrops in keratoconus and Descemetoceles, with impact on management approaches. It has been shown to contribute to the pathology and clinical signs observed in corneal infections and some corneal dystrophies. Early evidence suggests that it may have a role in the pathogenesis of keratoconus in relation to its elastin content. Its contribution to corneal biomechanics and glaucoma are subjects of current investigations.

Manual schism and intracameral air injection for impacted Descemet's membrane detachment

A woman in her 60s was referred to us for management of poor vision following cataract surgery in the right eye. She had undergone manual small incision cataract surgery 12 weeks earlier. Slit-lamp biomicroscopy revealed corneal oedema, a horizontal line at the upper border and the adhered inferior border of detached Descemet's membrane (DM). Clinical diagnosis of impacted Descemet's membrane detachment (DMD) was considered.Surgical intervention with manual schisis and intracameral injection of air was planned. Using the 'push technique,' we tried to place the tip of the 27 gauge cannula between the back of the cornea and detached DM. The tip of the 27 gauge cannula was behind the impacted DM, and air injection was unsuccessful. Using the back-up the 'pull technique,' bent tip of the 27 gauge cannula was used to pull the impacted DMD. This manoeuvre, disimpacted the inferior border and the air bubble, was injected using the 27 gauge cannula. The air bubble unfolded and reattached the DM successfully.

Unintentional Descemet Cleft Introduces Novel Mechanism of Maintenance of Corneal Clarity

PURPOSE

The purpose of this study was to report a case of corneal transparency for 7 months after the formation and persistence of a Descemet fluid cleft.

METHODS

We report the case of a 64-year-old woman undergoing anterior chamber reformation 2 months after Baerveldt implantation of the right eye. During the procedure, the ophthalmic viscoelastic was inadvertently injected into the posterior stroma, nearly isolating the corneal endothelial cell layer, and creating a Descemet fluid cleft filled with viscoelastic. The patient was managed conservatively and monitored near monthly for corneal decompensation.

RESULTS

The cornea remained centrally clear for 207 days after the initial anterior chamber reformation until the collapse of the viscoelastic cleft. When the cleft completely collapsed, the cornea became diffusely edematous, and the patient underwent cataract removal and intraocular lens placement without need for Descemet stripping endothelial keratoplasty to maintain vision. During these 7 months, the patient's best-corrected visual acuity remained stable at 20/25 +2 or better. Intraocular pressure was also stable, averaging 18.2 mm Hg.

CONCLUSIONS

We hypothesize that corneal transparency can be maintained in the absence of endothelial cell function provided that aqueous humor cannot reach the cornea and disrupt the arrangement of the interfibrillar space.

Pneumodescemetopexy With a Lower Concentration of Perfluoropropane (10% C3F8) in Descemet Membrane Detachment

A 75-year-old man with underlying left eye idiopathic orbital inflammatory disease and bilateral glaucoma suspect with cup disc ratio 0.7 underwent right eye phacoemulsification. Intraoperatively, Descemet tear and Descemet membrane detachment (DMD) occurred. Pneumodescemetopexy with air bubble was performed. His vision remained counting fingers and the cornea was oedematous three weeks after the operation. Anterior segment optical coherence tomography (ASOCT) showed extensive (80%) rhegmatogenous DMD with planar edge and a maximum of 460 micrometers separation from the stroma. Pneumodescemetopexy with low concentration perfluoropropane (10% C3F8) was performed together with postoperative positioning. On day five post-pneumodescemetopexy, his vision improved to 6/9, the cornea cleared with mild Descemet striae, and the gas bubble reduced to 30% fill. There was no DMD detected on ASOCT. His vision remained 6/9 and the residual gas bubble was 15% in the anterior chamber at two weeks post-pneumodescemetopexy. This case report suggests that pneumodescemetopexy with 10% C3F8 successfully reattached the large nonplanar rhegmatogenous DMD.

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.

A Comparative Study between Air Bubble Tamponade Alone versus Air Bubble Tamponade with Internal Fluid Aspiration for Nonplanar Descemet's Membrane Detachment after Phacoemulsification

Purpose

To compare the efficacy of air bubble tamponade alone versus air bubble tamponade with internal fluid aspiration for nonplanar Descemet's membrane detachment after clear corneal incision phacoemulsification.

Methods

This study is a prospective, intervention, comparative randomised clinical trial, conducted at a private eye centre, Ismailia, Egypt, from March 2019 to March 2020. It contained 30 eyes of 24 patients who had postphacoemulsification nonplanar Descemet's membrane detachment involving the periphery and the central area of the cornea (>50% of the cornea) with corneal oedema. The patients were divided into two groups: group A: patients with nonplanar DMD affecting the central cornea treated by air bubble tamponade only and group B: patients with nonplanar DMD affecting the central cornea treated by air bubble tamponade augmented by internal fluid aspiration. Trial Registration: This trial was registered at www.pactr.org and the identification number for the registry is PACTR202006612296119.

Results

During the 12-month study period, this study included 30 eyes (24 patients) out of 1356 phaco surgeries with postphacoemulsification nonplanar Descemet's membrane detachment. Six patients had DMD in both eyes, eight patients had DMD in the right eye, and ten patients had DMD in the left eye. All patients have successful surgeries without complications. The calculated incidence rate for visually significant DMD was 2.2% per year. The mean ± SD time interval from cataract surgery to the primary intervention was 4.2 ± 1.1 days. Descemet's membrane was attached in 56.25% of patients in group A (9 out of 16 eyes) and 92.6% of patients in group B (13 out of 14 eyes) with a minimum of one-month follow-up.

Conclusion

Air descemetopexy combined with the internal fluid aspiration demonstrated to be more efficient than air descemetopexy only to treat Descemet's membrane detachment following phacoemulsification. It should be tried before planning other major surgeries in patients with severe Descemet's membrane detachment.

Clinical course of lens capsule fragment adherent to the posterior corneal surface after cataract surgery

PURPOSE

The purpose of the study was to evaluate the clinical features and outcomes of lens capsule fragment (LCF) adherent to the posterior corneal surface after cataract surgery. Methods A total of 12 eyes from 12 patients were included with a mean follow-up duration of 19.4 ± 12.6 months. Demographics and clinical features were collected by reviewing medical records and slitlamp photographs. Outcome parameters included corrected distance visual acuity (CDVA), central corneal thickness, and anterior segment optical coherence tomography (AS-OCT) features. Results All LCF located centrally and remained fixed and turned to semitransparent in a mean time of 28.7 ± 20.1 days. The AS-OCT revealed an extra membrane at the posterior corneal surface, with an underlying intact Descemet membrane in 9 eyes. All patients experienced corneal edema associated with LCF, which was medically managed and resolved in a mean time of 58.1 ± 40.2 days. CDVA improved from logarithm of minimum angle of resolution scores of 0.91 ± 0.63 preoperatively to 0.25 ± 0.18 at 2 months after surgery. None of the patients expressed subjective visual complaints. Conclusions LCF adherent to the posterior corneal surface caused prolonged corneal edema after cataract surgery, but exhibited no clinically significant complications in the midterm follow-up. AS-OCT provided useful diagnostics and differentiating features.

"Descemet Membrane Detachment": A Novel Concept in Diagnosis and Classification

PURPOSE

To examine the optical coherence tomography (OCT) and histologic features of Descemet membrane detachment (DMD) to ascertain the involvement of the pre-Descemet layer (PDL).

DESIGN

Retrospective, observational case series.

METHODS

Clinical, histopathologic, and OCT features of a cohort of 41 cases with diagnosis of DMD from 4 centers were studied. OCT images were evaluated independently by 3 observers for number of detached layers (1 or 2), reflectivity, configuration (straight line or wavy), distance from posterior stroma, and presence or absence of a tear with any scrolling of the torn edges. Five had a histology specimen. The main outcome measure was the involvement of the PDL in DMD and its confirmation by histology.

RESULTS

Three types of DMD were identified: type 1, where the PDL and DM were detached together; type 2, where only the DM was detached; and mixed, where the PDL and DM were detached but also separated from each other. These were further found to be rhegmatogenous or nonrhegmatogenous depending on the presence of absence of a tear in DM or both layers. Histology confirmed involvement of PDL in all 5 cases and showed it to be infiltrated by cells in 3 of 5 cases.

CONCLUSIONS

The PDL is involved in DMD. This fact significantly changes our understanding of DMD and could have implications for management. The detached PDL can be infiltrated with cells. A prospective study in relation to etiology and types of DMD is needed.

Descemet membrane detachment

Descemet membrane detachment (DMD) is a potential vision-threatening complication that occurs most commonly after cataract surgery. DMD has also been reported to occur in various other surgeries such as keratoplasty, iridectomy, vitrectomy, trabeculectomy, holmium laser sclerostomy, alkali burn, and viscocanalostomy. Major risk factors include advanced age, preexisting endothelial diseases like Fuchs dystrophy or abnormality in the Descemet membrane and stromal interface, hard cataract, prolonged surgical time, ragged clear corneal incisions, and inadvertent trauma with blunt instruments or phacoemulsification probe. Most DMDs are peripheral and resolve spontaneously. Large, central DMDs if not managed appropriately may lead to corneal decompensation and opacification. Several authors have classified DMD depending on its configuration, height, extent, length, and position with respect to pupil. Anterior segment optical coherence tomography has been used to confirm and classify DMD and can also aid in deciding the management plan. Spontaneous reattachment of the DM with conservative management may occur in cases with small, peripheral, planar DMD with nonscrolled edges. Cases with nonplanar, central DMD, scrolled edges, and length >2 mm, however, have to be managed surgically. Descemetopexy is the gold standard for the management of DMD. Other management options include mechanical tamponade, suture fixation, descemetotomy, interface drainage, and keratoplasty. Prompt diagnosis and timely management often leads to a good visual outcome.

Use of Pressurized Air Infusion For Pre Descemet's Endothelial Keratoplasty (PDEK) - The Air Pump Assisted PDEK Technique

Purpose:

To assess the advantages offered by the air pump assisted PDEK technique that utilizes pressurized Anterior Chamber (AC) air infusion.

Methods:

Pressurized air infusion was provided through an anterior chamber maintainer connected to the fluid air exchange system of a posterior vitrectomy machine during surgery.

Results:

Pressurized air infusion within the AC helped perform Descemetorhexis, prevented bleeding during Peripheral Iridectomy (PI) and synechiolysis, prevented oozing of blood from peripheral corneal neovascularization into the AC and thus helped maintain a non-fibrinous AC environment. In addition, it helped in precise graft manipulation, centration, edge unfolding and unwrinkling after it was floated against the stroma as well as faster graft adhesion. It also prevented AC depth fluctuations during intra-cameral maneuvers and prevented intra-operative as well as post-operative graft detachment.

Conclusions:

This technique makes several steps of surgery easier and improves graft adhesion.

Recognizing and Managing Bullous Descemet Detachment Secondary to Accidental Hydroseparation During Phacoemulsification/Cataract Surgery by Relaxing Descemetotomy

PURPOSE

To report a new technique called relaxing Descemetotomy for treatment of bullous Descemet detachment (BDD) secondary to accidental hydroseparation of Descemet membrane (DM) during stromal hydration in cataract surgery.

METHODS

A clear corneal keratome entry was created close to the limbus extending inward to create a relaxing cut (ab externo relaxing Descemetotomy) on taut DM, thus creating an egress route for supra-Descemetic fluid (SDF). This was followed by pneumodescemetopexy to drain SDF internally.

RESULTS

Three patients with a history of unsuccessful pneumodescemetopexy and with planar or mildly convex separation of DM without break on anterior segment optical coherence tomography (ASOCT) underwent this procedure. All had successful reapposition of DM clinically and on ASOCT. All showed resolution of stromal edema and improved uncorrected and best-corrected visual acuity postoperatively.

CONCLUSIONS

Rarely stromal hydration performed with an irrigating cannula positioned too close to the posterior stroma can result in hydroseparation of DM creating BDD, seen intraoperatively as a fluid wave propagating across the posterior aspect of the cornea. Large folds, free mobility, and DM tear classically seen with rhegmatogenous Descemet detachment are not seen clinically or on ASOCT in BDD. Pneumodescemetopexy alone cannot resolve BDD because without a DM tear, SDF cannot evacuate. Combining relaxing Descemetotomy with pneumodescemetopexy allows SDF to drain internally and Descemet detachment to resolve. This technique has numerous advantages over classical venting incisions in terms of ease, preferable limbal location, larger incision size, absence of complications such as visual axis scars, irregular astigmatism, epithelial ingrowth, infectious keratitis, etc.

Corneal edema after phacoemulsification

Phacoemulsification is the most commonly performed cataract surgery in this era. With all the recent advances in investigations and management of cataract through phacoemulsification, most of the patients are able to achieve excellent visual outcome. Corneal edema after phacoemulsification in the immediate postoperative period often leads to patient dissatisfaction and worsening of outcome. Delayed onset corneal edema often warrants endothelial keratoplasty. This review highlights the etiopathogenesis, risk factors, and management of corneal edema in the acute phase including descemet's membrane detachment (DMD) and toxic anterior segment syndrome. Various investigative modalities such as pachymetry, specular microscopy, anterior segment optical coherence tomography, and confocal microscopy have been discussed briefly.

A retrospective study on the incidence of post-cataract surgery Descemet's membrane detachment and outcome of air descemetopexy

PURPOSE

To study the anatomic and functional outcome of air descemetopexy in postcataract surgery Descemet's membrane detachment (DMD).

DESIGN

Retrospective study.

METHODS

Setting: Institutional.

STUDY POPULATION

Records of 112 patients who underwent air descemetopexy for postcataract surgery sight-threatening DMD at Aravind Eye Hospital, Pondicherry, between January 2013 and December 2015 were studied.

MAIN OUTCOME MEASURES

Anatomical outcome refers to reattachment of the Descemet's membrane (DM). Functional outcome was given by the best-corrected visual acuity.

RESULTS

The mean age was 66.47±8.46 (SD) years, the male to female ratio was 45:67. The incidence of DMD was more in extracapsular cataract extraction (0.26%) and manual small incision cataract surgery (0.11%) than phacoemulsification (0.04%) (p=0.005 and p<0.0001). DMD was more common among surgical trainees (0.17%) than consultants (0.07%) (p≤0.0001). After primary air descemetopexy, 78 (71%) out of the 110 patients had DM reattachment. The complications noted after descemetopexy include persistent DMD (21.8%), corneal decompensation (7.3%), appositional angle closure (18%), pupillary block with air (2.7%) and uveitis (2.7%). Age, sex and timing of intervention did not influence the reattachment rate. Fifteen patients underwent repeat air descemetopexy for persistent DMD among whom nine (60%) had successful reattachment. Almost 75% of patients had vision better than 6/18 1 month after anatomically successful descemetopexy.

CONCLUSION

Air descemetopexy is a safe and efficient modality of treatment of DMD and should be tried even in patients with severe DMD before planning a major surgery like endothelial keratoplasty.

Air Pump-Assisted Graft Centration, Graft Edge Unfolding, and Graft Uncreasing in Young Donor Graft Pre-Descemet Endothelial Keratoplasty

PURPOSE

To assess an air pump-assisted technique for graft centration, graft edge unfolding, and graft uncreasing while performing pre-Descemet endothelial keratoplasty (PDEK) using young donor grafts.

METHODS

Continuous pressurized air infusion was used for graft centration, graft edge unfolding, and graft unwrinkling.

RESULTS

Ten eyes of 10 patients underwent PDEK with donors aged below 40 years. In all eyes, the donor scrolled into tight scrolls. In all cases, the air pump-assisted technique was effective in positioning and centering the graft accurately and in straightening infolded graft edges and smoothing out graft creases and wrinkles. Endothelial cell loss was 38.6%. Postoperative best-corrected visual acuity at 6 months was 0.66 ± 0.25 in decimal equivalent. Continuous pressurized air infusion acted as a third hand providing a continuous pressure head that supported the graft and prevented graft dislocation as well as anterior chamber collapse during intraocular maneuvering. Adequate maneuvering space was available in all cases, and bleeding, if any, was tamponaded successfully in all cases.

CONCLUSIONS

Although very young donor grafts may be used for PDEK, they are difficult to center and unroll completely before floating against host stroma. An air pump-assisted technique using continuous pressurized air infusion allows successful final graft positioning even with very young donor corneas. It thus makes surgery easier as several key steps are made easier to handle. It additionally helps in tamponading hemorrhage during peripheral iridectomy, increasing surgical space, preventing fluctuations in the anterior chamber depth, and promoting graft adherence.

Descemet membrane detachment during cataract surgery: etiology and management

PURPOSE OF REVIEW

The review updates the mechanisms, clinical presentations, diagnoses, and managements of Descemet membrane detachment during cataract surgery.

RECENT FINDINGS

The advent of new imaging techniques such as anterior segment optical coherence tomography and better comprehension of the clinical and pathological aspects of detachment have improved the diagnosis and treatment of this complication to the extent that the first algorithms and protocols have been proposed.

SUMMARY

Though infrequent, Descemet membrane detachment is a complication of intraocular surgery, including cataract surgery and phacoemulsification. Since the first systematic description and classification in the literature by Samuels in 1928 and its characterization as a potential sight-threatening condition by Scheie in 1964, plenty of retrospective and anecdotal evidence contribute to uncertainty and debate. The main controversy still lies in the choice between conservative treatment in hopes of spontaneaous reattachment and surgical treatment in a timely manner to maximize visual recovery.