Iatrogenic Descemet membrane detachment in the donor lenticule during Descemet stripping automated endothelial keratoplasty

Abstract

A female patient in her 60s presented with an 8-month history of decreased vision in her right eye. She was diagnosed with pseudophakic bullous keratopathy (PBK), and Descemet stripping automated endothelial keratoplasty (DSAEK) surgery was planned. Intraoperative Descemet membrane detachment (DMD) occurred while inserting the lenticule using the Sheets glide technique. The detachment of the Descemet membrane was detected immediately, and air descemetopexy was performed intraoperatively. Postoperatively, the donor lenticule was attached properly to the stromal bed, except for a focal DMD approximately 3 mm in the inferior part of the lenticule. A second descemetopexy was performed 5 days later, resulting in a complete attachment. A DMD in DSAEK lenticule is an extremely rare complication. Early detection and timely intervention with descemetopexy helped achieve a good anatomical and functional outcome.

Background

In India, pseudophakic bullous keratopathy (PBK) is the most common indication for endothelial keratoplasty.¹ Descemet stripping automated endothelial keratoplasty (DSAEK) is preferred over Descemet membrane endothelial keratoplasty in complex cases of PBK. Several techniques have been described to insert the donor DSAEK lenticule into the anterior chamber. The push-in method is commonly used, either over a cushion of the ocular viscoelastic device (OVD) or over a simple plastic device called Sheets glide.² The risk of lenticule detachment, following DSAEK surgery, has been reported frequently. The incidence of lenticule detachment ranges from 0% to 82%, with an average rate of 14.5%.^{3 4} However, it is rare to have an intraoperative detachment of the Descemet membrane from the donor lenticule. We report this unusual complication, which was successfully managed by air descemetopexy.

Case presentation

A female patient in her 60s presented with an 8-month history of decreased vision in her right eye. She had undergone cataract surgery 18 years ago, with a good postoperative result. She was mono-ocular, with a phthisical left eye. She had lost vision in her left eye 25 years previously following blunt trauma. At presentation, her best corrected visual acuity was 20/200 in the right eye, with no perception of light in the left eye. A slit lamp examination of the right cornea showed stromal oedema in the inferotemporal quadrant, obscuring the visual axis (figure 1A). An angle-supported anterior chamber intraocular lens (ACIOL) and a thick retropupillary membrane were also observed.

Figure 1.

Slit lamp photographs of the right eye. (A) Preoperative image showing stromal oedema involving the inferotemporal quadrant obscuring the visual axis and the presence of ACIOL and retropupillary membrane. (B) Sheets glide (Madhu Instruments, India) was used for DSAEK lenticule insertion in our case. (C) First postoperative day image showing the DSAEK lenticule well attached to the host stromal bed, lenticular oedema and persistent DMD involving an inferior 3 mm of DSAEK lenticule (yellow circle). ACIOL, anterior chamber intraocular lens; DMD, Descemet membrane detachment; DSAEK, Descemet stripping automated endothelial keratoplasty.

She was scheduled for a DSAEK with retropupillary membranectomy and a possible ACIOL exchange. A precut donor DSAEK graft stored in the McCarey-Kaufman medium was used. The donor age was in 40s, the endothelial cell count was 2597 cells/mm² and the lenticule thickness was 122 microns. Intraoperatively, the ACIOL was stable; therefore, an exchange was deferred. The membranectomy was performed using a 23-gauge vitrectomy cutter with a cut rate of 100 rpm. Corneal epithelium was debrided for better visualisation of anterior chamber contents. The recipient’s Descemet membrane was scored and stripped over the central 8 mm region. An 8 mm suction trephine (Katena Barron vacuum donor cornea punch, Katena Products, New Jersey, USA) was used to prepare the donor lenticule. Prior to insertion, a Sheets glide (Madhu Instruments, New Delhi, India) (figure 1B) was placed into the anterior chamber through a 4 mm superior limbal incision and a small drop of cohesive OVD was placed over it. The trephined lenticule with an overlying stromal cap was lifted using Paton’s spatula and placed over the glide with the endothelial side down. The anterior stromal cap was removed, and the lenticule was gently pushed into the anterior chamber using a Sinskey hook. A Descemet membrane detachment (DMD) was immediately detected after implantation, involving the inferior half of the lenticule. A membrane which was partially attached to the posterior surface of the DSAEK lenticule was noted and the inferior detached part was moving with fluid currents generated during interface irrigation, indicating the presence of a DMD. The orientation of the detachment was identified, and an air bubble that filled the anterior chamber was injected. The air bubble attached both the DSAEK lenticule and the DMD.

On the first postoperative day, the donor lenticule was attached to the posterior stroma of the host properly. However, the DMD persisted in the inferior 3 mm of the donor lenticule (figure 1C). The patient was started on topical prednisolone acetate 1% eye drops every hour and moxifloxacin 0.5% eye drops four times per day. However, at the next visit 5 days later, the dimensions of the DMD remained the same, and there was no sign of spontaneous resolution. Therefore, an air descemetopexy was scheduled. A full chamber air bubble was injected into the anterior chamber via paracentesis and maintained for 10 min.

Investigations

Anterior segment optical coherence tomography (AS-OCT) done preoperatively confirmed stromal oedema and epithelial hypertrophy (figure 2A). On the first postoperative day after DSAEK, the AS-OCT showed a well-attached DSAEK lenticule, but there was an DMD in the inferior part of the lenticule (figure 2B). After descemetopexy, the DMD in the DSAEK lenticule was completely attached (figure 2C).

Figure 2.

Anterior segment optical coherence tomography: (A) Preoperative—showing prominent stromal oedema and epithelial hypertrophy in the inferior half of the cornea. (B) Day 1 post-DSAEK—showing well-attached DSAEK lenticule to the host stromal bed and a detachment involving the inferior part of the DSAEK lenticule (white square box showing magnified view). (C) One week post-descemetopexy—showing resolved DMD (white box). DMD, Descemet membrane detachment; DSAEK, Descemet stripping automated endothelial keratoplasty.

Outcome and follow-up

Descemetopexy resulted in the complete attachment of the residual DMD. This was confirmed postoperatively through AS-OCT (figure 2C). One month postoperatively, her uncorrected visual acuity improved to 20/60. The DM and lenticule remained completely attached.

Discussion

Donor insertion techniques in DSAEK can be broadly classified into pull-through and push-in techniques. The pull-through technique uses various devices, such as the Busin glide (Asico, Westmont, Illinois, USA), Macaluso inserter (E. Janach, Como, Italy) and the Endoglide (Angiotech, Vancouver, British Columbia, Canada). It can also be performed with the help of a 10-0 suture. The push-in technique uses Sheets glide, forceps technique, EndoSerter (Ocular Systems, Winston-Salem, North Carolina, USA), Endoshield/EndoInjector (Keramed, San Jose, California, USA) and Neusidl injector (Fischer Surgical, Arnold, Missouri, USA).⁵

Mehta et al² first described Sheets glide for DSAEK donor tissue insertion. The technique has gained popularity as it is simple and economical. The width of the glide is 5 mm, and most surgeons prefer to insert the lenticule through a 4 mm incision. Therefore, it is common practice to trim the glide tip to the desired size. However, these may leave behind irregular edges, which can potentially snag the tissue and cause DMD. In this case, the modified Sheets glide used had a small platform with a corrugated rough surface and a sharp convex edge. The use of cohesive OVD has been recommended during insertion of the lenticule to prevent endothelial damage; however, surgeons often prefer to insert the lenticule over a cushion of balanced salt solution or with minimum OVD to avoid its entry into the interface. This is another critical step that could damage the tissue. Copious cohesive OVD was used in this case however. Despite these potential risks, such complications are extremely rare.

Romaniv et al⁶ reported a case of DMD in DSAEK performed for failed penetrating keratoplasty. However, they did not detect the detachment intraoperatively. It eventually led to primary graft failure and necessitated a repeat penetrating keratoplasty. In our case, we noticed the DMD in the donor lenticule immediately after insertion. We found that the edges of the Sheets glide were irregular, which could have hooked the DM during graft insertion, resulting in detachment. Lenticule detachment in DSAEK is managed by rebubbling. In our case, we only had a localised area of persistent DMD postoperatively. The lenticule had attached well.

DMD is a sight-threatening complication which can occur postintraocular surgeries especially cataract surgery, penetrating keratoplasty, deep anterior lamellar keratoplasty and glaucoma filtering surgeries. Depending on the location, extent, type and depth of the detachment, various modalities are used to manage DMD including observation, topical steroids and hyperosmotic agents, pneumatic descemetopexy, transcorneal suture fixation, and endothelial keratoplasty in advanced and non-resolving cases.⁷ Small, peripheral DMDs usually attach spontaneously with conservative management.⁸ However, the same may not be applicable in cases of DMD in a DSAEK donor lenticule, as we did not find any sign of spontaneous resolution with conservative management. Our patient was mono-ocular, which made it necessary for us to manage the residual DM detachment swiftly. Therefore, we performed descemetopexy with an intracameral air injection.

Air descemetopexy has shown excellent outcomes for DMD postcataract surgery.^{9 10} The presence of an ACIOL is usually associated with an absent lens-iris diaphragm and open communication between the anterior chamber and vitreous cavity. Therefore, it becomes difficult to retain an air bubble in the anterior chamber. This is probably why the inferior DMD persisted. To the best of our knowledge, this is the first report of an intraoperative DMD in a donor lenticule in DSAEK, which was identified intraoperatively and managed with descemetopexy.

Patient’s perspective.

I had unfortunately lost vision in my left eye many years ago in an accident and am completely dependent on my right eye. I developed cataract in my right eye around 18 years ago and underwent surgery in my hometown and thankfully I had good recovery and was able to see well and carry on with my life after surgery. But, around 8 months ago, I started developing blurred vision in my right eye. Initially I disregarded it, but to my surprise it kept getting worse gradually. I was really afraid as I thought I was going blind. I immediately went to an ophthalmologist in my hometown and he told me I had some issue with my cornea and I would have to consult a specialist in that field for further management. This really terrified me. My family members were also very apprehensive. We immediately decided to go to a tertiary care centre. My doctor was very kind to me from the first visit and explained my condition in detail and how he can help recover it. He told me that I had a condition called pseudophakic bullous keratopathy and due to damage to the cells in the inner layer of cornea, I had fluid entering into my cornea and hence had blurring of vision. He told me that I would need a partial thickness corneal transplant surgery. Though I was very scared, he reassured me and gave me the confidence to go ahead with the surgery. I finally underwent surgery after consultation with my family members. Post surgery, I was informed that although the surgery was successful, there was a small problem as a layer of the graft in my eye was partially detached. I was told that I may need a minor surgery again to attach the layer. On the fifth day after surgery, I was taken up for air injection to attach the detached layer. After surgery, I was informed that everything went well. To my relief, I recovered well and had very good vision in a few days. I am very grateful for all the care and support I received from the entire team in the hospital. I am so relieved to be able to see properly again.

Learning points.

• Occurrence of Descemet membrane detachment (DMD) in a Descemet stripping automated endothelial keratoplasty (DSAEK) lenticule is an extremely rare complication.

• It is challenging to identify DMD in a DSAEK lenticule intraoperatively in the anterior chamber due to compromised visualisation due to stromal oedema in such cases.

• Timely recognition and appropriate management with descemetopexy helped prevent permanent endothelial cell damage and primary graft failure in our patient.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).