Myth exploded
CASE REPORT
Incidental central tear in Descemet membrane endothelial complex during Descemet membrane endothelial keratoplasty Vikas Mittal,1 Ruchi Mittal,2 Rajat Jain,3 Virender S Sangwan4 1
Department of Cornea and Anterior Segment Services, Sanjivni Eye Care, Ambala, Haryana, India 2 Department of Vitreo-retina Services, Sanjivni Eye Care, Ambala, Haryana, India 3 Department of Cornea and Anterior Segment Services, L V Prasad Eye Institute, Bhubaneshwar, Odisha, India 4 Department of Cornea and Anterior Segment Services, L V Prasad Eye Institute, Hyderabad, Andhra Pradesh, India Correspondence to Dr Virender Sangwan, [email protected]
SUMMARY Descemet membrane endothelial keratoplasty (DMEK) was performed in a 70-year-old man diagnosed with pseudophakic bullous keratopathy. During Descemet endothelial complex (DEC) preparation, a central tear was noticed in the DMEK graft. However, the surgery was continued. On sixth postoperative day, a small fluid pocket was observed between the DEC and the posterior host stroma in inferior third of the graft area. It was, however, decided to observe it for spontaneous attachment. At 2 weeks, the inferior DEC detachment had increased with overlying corneal oedema. Descemetopexy with 100% air was performed the same day which reattached the DEC. Subsequently, DEC remained attached and at the last follow-up of 2 months, DEC was well opposed with a clear overlying cornea. The final best-corrected Snellen’s visual acuity was 20/60. A small tear in the DEC does not necessitate tissue replacement and a good anatomical and visual outcome can be achieved in such cases.
in the past 1 month. There was no history of redness, watering or pain in the eye. He had undergone a cataract surgery OD 10 years ago, the details of which were not available. However, he was able to see clearly and perform daily activities until his symptoms had started. At presentation, he had a best corrected Snellen’s visual acuity (BCVA) of 3/60 OD and 6/9 in the left eye (OS)). Clinical examination of OD revealed a mild congestion in the conjunctiva, diffuse stromal corneal oedema with a normal anterior chamber (AC) and a posterior chamber intraocular lens (IOL). As fundus view was obscured due to the corneal oedema; ultrasound was requested which suggested a normal posterior segment. Examination of OS was essentially normal with a posterior chamber IOL in place. A clinical diagnosis of pseudophakic corneal oedema was made (figure 1A). The patient was advised endothelial keratoplasty and DMEK was performed (VM).
BACKGROUND
Surgery DMEK donor preparation
Endothelial keratoplasty has been the treatment of choice for management of corneal endothelial disorders over the past few years.1 As compared with Descemet stripping endothelial keratoplasty (DSEK), Descemet membrane endothelial keratoplasty (DMEK) provides better and faster visual and refractive outcomes, has less graft rejection rates and comparable endothelial cell loss with DSEK.2 3 However, surgery is technically more complex with a steep surgeon’s learning curve and higher possibility of donor tissue damage and postoperative graft detachments.2 4 5 Reports of damage to the Descemet membrane endothelial complex (DEC), and hence tissue loss, are common in the recent literature.3 6 Similar to the management of postcataract surgery, Descemet membrane (DM) detachment7 and graft detachments in DMEK have been shown to be successfully managed with air descemetopexy.2 Here we report a good anatomical and visual outcome of a case of DMEK where surgery was continued in spite of an accidental central tear during tissue preparation in the DEC. To cite: Mittal V, Mittal R, Jain R, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2013202935
CASE PRESENTATION History and clinical examination A 70-year-old, non-diabetic, healthy man presented to us with a 3-month history of gradual diminution of vision in his right eye (OD) which had increased
Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
DEC that consisted of posterior DM with its endothelial monolayer was prepared from a 62-year-old, phakic donor corneal button that had an endothelial cell count of 2122 cells/mm2. It was stored in optisol medium and death-enucleation time was 96 h. In brief, corneoscleral (CS) button was placed with ‘endothelial side up’ on a teflon block and few drops of corneal preservation medium (optisol) were placed over it such that the liquid reached the edge of CS rim. It was intentionally tried to keep tissue–teflon interface free of fluid to minimise tissue movement during donor harvesting. An 8.5 mm corneal trephine (Madhu instruments, Delhi, India) was stained with gentian violet at the edge and then used to make initial central partial thickness groove in CS button. The idea was to get a starting point to separate the DM from posterior stroma. The tip of a Sinskey hook (Madhu instruments, Delhi, India) was then used to create a cleft between DM and underlying stroma all around. At least 2–3 mm of DM lift was assured to help in holding for further separation. Subsequently, the edge of DM was held with one or two blunt suture tying forceps and gently pulled in direction parallel to endothelium and towards opposite edge. In one go, 20–30% of DM was separated. This was performed in each quadrant until the DM was separated from the stroma. It took 4–5 circles to separate the whole of DM. Simultaneous and 1
Myth exploded Figure 1 Composite of slit lamp images showing diffuse and slit images of the patient. (A) Diffuse illumination image showing central and inferior cornea oedema at presentation; (B) postoperative day 1 photograph after Descemet membrane endothelial keratoplasty (DMEK) showing reduction in corneal oedema and an anterior chamber filled half with air bubble; (C) diffuse and (D) slit views at postoperative 3 weeks showing inferior corneal oedema with Descemet endothelial complex (DEC) separation; and (E) diffuse and (F) slit views at postoperative 2 months after air descemetopexy was performed showing an attached DMEK DEC with an overlying clear cornea.
coordinated movements of both hands were performed when the edge of DM was held with two forceps. Also, it was ensured to keep the DM in corneal preservation medium all the time. After completion of DM stripping, it was left on the donor tissue with corneal preservation medium over DM until its injection into the eye.
Recipient preparation The surgery was performed in peribulbar anaesthesia. Epithelium was removed to improve the visibility. DM was stripped under AC maintainer as performed during routine DSEK.8 A small peripheral iridotomy was performed at 6 o’clock position using an automated vitrector. Finally, the AC maintainer was removed and paracentesis wound was hydrated.
solution drop by drop from the edge of CS rim and avoid direct instillation on endothelium. After staining, a small central tear of around 1×2.5 mm was noticed in DM (figure 2A). Since the tear had a flap attached at one end, it was decided to continue with the surgery. During washing of dye with BSS, the DEC got rolled up spontaneously with the endothelium at the outer side. It was aspirated into a customised injector mounted on a 2 mL syringe. The customised DEC injector was prepared from routine Akreos (Bausch & Lomb, USA) IOL injector (figure 2B,C). The injector was cut from proximal end and attached to a silicon tube used for phacoemulsification. Hence a ‘no-touch’ technique was used for donor insertion into the eye. Before injecting the DEC into the eye, AC was decompressed by tapping the posterior lip of paracentesis wound. DEC was injected into the AC with one push.
Donor injection The harvested DEC was stained with trypan blue 0.06% (Auroblue, Aurolab, Madurai, India) to improve visualisation of DEC inside the eye. It was ensured to instil dye or balanced salt 2
Donor unfolding The graft was oriented with the endothelial side down (donor DM facing recipient posterior stroma) onto the recipient Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
Myth exploded Figure 2 (A) Intraoperative photograph showing a central tear in the Descemet endothelial complex (DEC) during donor preparation. (B and C) the customised DEC injector.
posterior stroma by careful, indirect manipulation of the tissue with air and fluid. Fluid waves from the side ports and intermittent decompression of side ports along with repeated tapping on the corneal surface helped in DEC unfolding. While unfolding, the edges of DM folds should face the corneal stroma and not the iris (video 1). Once the proper direction of unfolding was confirmed, a small air bubble was injected below the DEC.
Surface strokes (and not massage) were used to unfold it further. Finally, a large air bubble was used and AC was filled completely with air. An air tight globe was achieved and maintained since an inferior peripheral iridotomy had been performed. Topical 5% povidone iodine, homatropine 2% and prednisolone forte 1% eye drops were instilled and the eye was patched.
Figure 3 Anterior segment optical coherence tomography pictures of the inferior cornea on (A) postoperative day 1 showing an attached Descemet membrane endothelial keratoplasty (DMEK) graft; (B) on postoperative day 6 when a thin Descemet membrane separation was seen; (C) at postoperative week 3 when the DMEK separation had increased with overlying corneal oedema; and (D) 1 month after successful repeat air injection was performed showing an attached DMEK graft with a clear overlying cornea.
Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
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Myth exploded
Figure 4 Macular Optical Coherance Tomograohy scan showing cystoids macular edema, cause for a decreased visual acuity despite clear cornea.
DIFFERENTIAL DIAGNOSIS The history of cataract surgery along with corneal oedema on examination clinched the clinical diagnosis of pseudophakic bullous keratopathy. A suspicion of Fuchs endothelial dystrophy was ruled out by the normal specular endothelial counts in the other eye.
TREATMENT The patch was opened after 2 h and an attached DM was confirmed on slit lamp. It was confirmed whether the air bubble was above iridectomy. The patient was prescribed topical prednisolone 1% two hourly, moxifloxacin 0.5% four times per day and homatropine 2% two times per day.
INVESTIGATIONS The attached DEC was confirmed with anterior segment optical coherence tomography (AS-OCT: Carl Zeiss Meditec, USA; 4
figure 3A). However, on sixth postoperative day, a small fluid pocket was observed between the DEC and the posterior host stroma in inferior third of the graft area (figure 3B). When the patient presented subsequently after 2 weeks, the inferior DEC detachment had increased with overlying corneal oedema (figure 3C). One month after descemetopexy, the DEC was attached with a clear overlying cornea (figure 3D).
OUTCOME AND FOLLOW-UP On first postoperative day, DEC was attached with reduction in the overlying corneal oedema and air bubble filling half of AC (figure 1B). The attached DEC was confirmed with AS-OCT (Carl Zeiss Meditec, USA; figure 3A). The central DEC tear was not noticed at this examination. The patient was discharged on topical antibiotics and steroids. On sixth postoperative day, a small fluid pocket was observed between the DEC and the posterior host stroma in inferior third of the graft area (figure 3B). Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
Myth exploded
Figure 5 Specular photo-micrograph showing the endothelial cell count of 1580 cells/mm2 at 2 months follow-up. As the detachment was very small, it was decided to observe it for spontaneous attachment.9 However, when the patient presented after 2 weeks, the inferior DEC detachment had increased with overlying corneal oedema (figure 1C,D) which was also confirmed on AS-OCT (figure 3C). Descemetopexy with 100% air was performed the same day which reattached the DEC. Subsequently, DEC remained attached and at the last follow-up of 2 months, DEC was well opposed with a clear overlying cornea (figures 1E,F and 3D). The final BCVA was 20/ 60. The reason for low visual acuity was associated cystoid macular oedema (figure 4). Specular count at 2 months postoperative period was 1580 cells/mm2 (figure 5).
DISCUSSION DMEK involves stripping of an intact DM from the graft stroma, its insertion into the host AC and its attachment to the host stroma.1 Each step is technically demanding due to the thin and delicate nature of the DM which is prone to damage at every step.4 Although various modifications have been tried in lenticule preparation,10 tissue loss remains a significant concern especially in hands of less experienced surgeons. Guerra et al,3 in their series of 136 eyes, have reported tissue loss in 4.2% of cases. Tourtas et al reported a series of three patients in which the DM was accidentally torn into two pieces during graft preparation. However, both pieces of DEC complex could be successfully implanted into the AC with good outcomes at 6 months.7 We performed DMEK in a 70-year-old man diagnosed with pseudophakic bullous keratopathy. During lenticule preparation, we noticed a small central tear in the DM endothelial complex. This was probably due to the learning curve of the surgeon (VM) which in the case of DMEK has been reported to be steep.11 While Price et al12 have reported a tissue wastage of 8% in a series of 66 eyes, Tourtas et al attained successful outcomes after implantation in three cases in which the DEC had been completely torn into two pieces. They, however, required a repeat air injection in each case.7 In our case, the central tear in DEC was Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
small in area and had a flap attached at one side. The flap was likely to attach with air at a desired position and the surgery was continued. The decision to continue was also based on the reports of successful spontaneous attachments of detached DM after cataract surgery.13 Also, the option of repeating the endothelial keratoplasty early, if DMEK failed, was kept in mind. On postoperative day 1, we found an attached DM endothelial complex with air filling half of the AC. However, on postoperative day 6, partial separation of the DMEK graft was noticed with an overlying corneal oedema. Earlier reports on spontaneous attachments of DMEK lenticule9 and re-endothelialisation of the recipient posterior stroma occurring as early as 5 weeks exist.14 Also, the corneal oedema has been reported to spontaneously clear in presence of partial detachment from periphery inwards.15 Our patient, however, had a small hole in the otherwise attached DMEK surrounding it. Hence, a decision against intervention was made. The patient was, however, advised to lie down in supine position as reported earlier.14
Video 1 The surgery. 5
Myth exploded Subsequently, at 3 weeks postoperatively, the corneal oedema had increased to involve a larger inferior area and DMEK graft detachment was observed in the corresponding area. Repeat air injection for detached DMEK graft is well known. It was required in 38 eyes (63%) in the series reported by Price et al12 and was successful. Descemetopexy was hence performed with air and was successful in attachment of the graft in our case. Subsequently, the DMEK complex remained attached to the posterior stroma, the overlying oedema gradually cleared, visual acuity improved at 2 months follow-up and the tear in the DMEK DEC was unnoticeable. The endothelial cell loss at the end of 2 months was 25.5%, which is less than the reported endothelial cell loss at 6 months.1 Though the follow-up is limited, most of the DMEK detachments and the endothelial cell loss post-DMEK are known to occur in the intraoperative and the early postoperative period.14 15 Hence, the graft is expected to remain attached and function adequately in future. The pertinent query in our case was to assess the possible reason of graft detachment. Dirisamer et al14 have defined clinically significant graft detachment post-DMEK as a lack of adherence of the donor DM to the recipient posterior stroma, reducing visual outcome and/or necessitating a secondary intervention. Partial detachments are known to be more common.14 15 Dirisamer et al14 reported the graft detachment rate of 24% post-DMEK, 12% being clinically significant. Various factors have been shown to influence graft detachment post-DMEK like the area of DM stripping less than the DMEK DEC and hence an overlap and the use of viscoelastic instead of air for descemetorhexis.14 15 Another significant factor which contributes to the DMEK detachment is the status of the air fill at the completion of the surgery. While Dirisamer et al,14 15 Kruse et al5 and Liarakos et al16 recommend sufficient air bubble for 45–60 min, Price et al12 performed an inferior peripheral iridotomy during each case, with AC 90% filled with air at the end of surgery and checked each patient an hour or two afterwards to ensure patency of the iridotomy. Other reasons reported for DMEK graft detachment are inward folds of DMEK graft which tend to roll away, further increasing the area of detachment, in sufficient air fill in a vitrectomised eye, insertion of upside-down graft irido-graft synechiae, poor endothelial morphology and stromal irregularity under the main incision.14 DMEK detachments are most commonly seen in the inferior DMEK graft due to the persistence of the air bubble in the superior quadrant for a longer period of time as was seen in our case.14 The detachment of the DMEK DEC in our case could either be due to the iatrogenic DM tear created during DEC preparation or it could be due to the routine high DMEK graft
Learning points ▸ Descemet membrane endothelial keratoplasty (DMEK) is a technically demanding surgery with a steep learning curve. ▸ Tissue loss is common with DMEK. It, however, decreases with the increasing experience of the surgeon. ▸ A small tear in the Descemet endothelial complex does not necessitate tissue replacement. ▸ Good anatomical and visual outcome can be achieved even in cases with a torn DMEK graft.
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detachment rates, which is reported as high as 82% (31/38 eyes, Tourtas et al).2 It has also been reported that DMEK graft required significantly higher number of air injections for attachment when tissues preserved in optisol-GS medium were used as compared with organ culture-stored donors. The tissue used in our patient had also been stored in optisol medium.17 However, detachment of a previously attached DMEK graft made us to believe that the detachment could have occurred due to the gradual seepage of the aqueous through the flap hole. Contributors RJ and VM performed the literature review, analyzed the data and wrote the manuscript. RJ, VM and RM were responsible for the conception of the article and design. RM and VSS revised the article critically for important intellectual content. Competing interests None. Patient consent Obtained. Provenance and peer review Not commissioned; externally peer reviewed.
REFERENCES 1 2
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Anshu A, Price MO, Tan DTH, et al. Endothelial keratoplasty: a revolution in evolution. Surv Ophthalmol 2012;57:236–52. Tourtas T, Laaser K, Bachmann BO, et al. Descemet membrane endothelial keratoplasty versus descemet stripping automated endothelial keratoplasty. Am J Ophthalmol 2012;153:1082–90. Guerra FP, Anshu A, Price MO, et al. Descemet’s membrane endothelial keratoplasty: prospective study of 1-year visual outcomes, graft survival, and endothelial cell loss. Ophthalmology 2011;118:2368–73. Patel SV. Graft survival and endothelial outcomes in the new era of endothelial keratoplasty. Exp Eye Res 2012;95:40–7. Kruse FE, Laaser K, Cursiefen C, et al. A stepwise approach to donor preparation and insertion increases safety and outcome of Descemet membrane endothelial keratoplasty. Cornea 2011;30:580–7. Tourtas T, Heindl LM, Kopsachilis N, et al. Use of accidentally torn descemet membrane to successfully complete Descemet membrane endothelial keratoplasty. Cornea 2013;32:1418–22. Jain R, Murthy SI, Basu S, et al. Anatomical and visual outcomes of descemetopexy in post cataract surgery Descemet’s membrane detachment. Ophthalmology 2013;120:1366–72. Mittal V, Mittal R, Sangwan VS. Successful Descemet stripping endothelial keratoplasty in congenital hereditary endothelial dystrophy. Cornea 2011;30:354–6. Balachandran C, Ham L, Verschoor CA, et al. Spontaneous corneal clearance despite graft detachment in Descemet membrane endothelial keratoplasty. Am J Ophthalmol 2009;148:227–34. Dapena I, Ham L, Droutsas K, et al. Learning curve in Descemet’s membrane endothelial keratoplasty: first series of 135 consecutive cases. Ophthalmology 2011;118:2147–54. Price MO, Price FW Jr. Descemet’s membrane endothelial keratoplasty surgery: update on the evidence and hurdles to acceptance. Curr Opin Ophthalmol 2013;24:329–35. Price MO, Giebel AW, Fairchild KM, et al. Descemet’s membrane endothelial keratoplasty: prospective multicenter study of visual and refractive outcomes and endothelial survival. Ophthalmology 2009;116:2361–8. Minkovitz JB, Schrenk LC, Pepose JS. Spontaneous resolution of an extensive detachment of Descemet’s membrane following phacoemulsification. Arch Ophthalmol 1994;112:551–2. Dirisamer M, van Dijk K, Dapena I, et al. Prevention and management of graft detachment in Descemet membrane endothelial keratoplasty. Arch Ophthalmol 2012;130:280–91. Dirisamer M, Dapena I, Ham L, et al. Patterns of corneal endothelialization and corneal clearance after Descemet membrane endothelial keratoplasty for Fuchs endothelial dystrophy. Am J Ophthalmol 2011;152:543–55. Liarakos VS, Dapena I, Ham L, et al. Intraocular graft unfolding techniques in Descemet membrane endothelial keratoplasty. Arch Ophthalmol 2013;131:29–35. Laaser K, Bachmann BO, Horn FK, et al. Donor tissue culture conditions and outcome after Descemet membrane endothelial keratoplasty. Am J Ophthalmol 2011;151:1007–18.
Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
Myth exploded
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Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
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CASE REPORT
Incidental central tear in Descemet membrane endothelial complex during Descemet membrane endothelial keratoplasty Vikas Mittal,1 Ruchi Mittal,2 Rajat Jain,3 Virender S Sangwan4 1
Department of Cornea and Anterior Segment Services, Sanjivni Eye Care, Ambala, Haryana, India 2 Department of Vitreo-retina Services, Sanjivni Eye Care, Ambala, Haryana, India 3 Department of Cornea and Anterior Segment Services, L V Prasad Eye Institute, Bhubaneshwar, Odisha, India 4 Department of Cornea and Anterior Segment Services, L V Prasad Eye Institute, Hyderabad, Andhra Pradesh, India Correspondence to Dr Virender Sangwan, [email protected]
SUMMARY Descemet membrane endothelial keratoplasty (DMEK) was performed in a 70-year-old man diagnosed with pseudophakic bullous keratopathy. During Descemet endothelial complex (DEC) preparation, a central tear was noticed in the DMEK graft. However, the surgery was continued. On sixth postoperative day, a small fluid pocket was observed between the DEC and the posterior host stroma in inferior third of the graft area. It was, however, decided to observe it for spontaneous attachment. At 2 weeks, the inferior DEC detachment had increased with overlying corneal oedema. Descemetopexy with 100% air was performed the same day which reattached the DEC. Subsequently, DEC remained attached and at the last follow-up of 2 months, DEC was well opposed with a clear overlying cornea. The final best-corrected Snellen’s visual acuity was 20/60. A small tear in the DEC does not necessitate tissue replacement and a good anatomical and visual outcome can be achieved in such cases.
in the past 1 month. There was no history of redness, watering or pain in the eye. He had undergone a cataract surgery OD 10 years ago, the details of which were not available. However, he was able to see clearly and perform daily activities until his symptoms had started. At presentation, he had a best corrected Snellen’s visual acuity (BCVA) of 3/60 OD and 6/9 in the left eye (OS)). Clinical examination of OD revealed a mild congestion in the conjunctiva, diffuse stromal corneal oedema with a normal anterior chamber (AC) and a posterior chamber intraocular lens (IOL). As fundus view was obscured due to the corneal oedema; ultrasound was requested which suggested a normal posterior segment. Examination of OS was essentially normal with a posterior chamber IOL in place. A clinical diagnosis of pseudophakic corneal oedema was made (figure 1A). The patient was advised endothelial keratoplasty and DMEK was performed (VM).
BACKGROUND
Surgery DMEK donor preparation
Endothelial keratoplasty has been the treatment of choice for management of corneal endothelial disorders over the past few years.1 As compared with Descemet stripping endothelial keratoplasty (DSEK), Descemet membrane endothelial keratoplasty (DMEK) provides better and faster visual and refractive outcomes, has less graft rejection rates and comparable endothelial cell loss with DSEK.2 3 However, surgery is technically more complex with a steep surgeon’s learning curve and higher possibility of donor tissue damage and postoperative graft detachments.2 4 5 Reports of damage to the Descemet membrane endothelial complex (DEC), and hence tissue loss, are common in the recent literature.3 6 Similar to the management of postcataract surgery, Descemet membrane (DM) detachment7 and graft detachments in DMEK have been shown to be successfully managed with air descemetopexy.2 Here we report a good anatomical and visual outcome of a case of DMEK where surgery was continued in spite of an accidental central tear during tissue preparation in the DEC. To cite: Mittal V, Mittal R, Jain R, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2013202935
CASE PRESENTATION History and clinical examination A 70-year-old, non-diabetic, healthy man presented to us with a 3-month history of gradual diminution of vision in his right eye (OD) which had increased
Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
DEC that consisted of posterior DM with its endothelial monolayer was prepared from a 62-year-old, phakic donor corneal button that had an endothelial cell count of 2122 cells/mm2. It was stored in optisol medium and death-enucleation time was 96 h. In brief, corneoscleral (CS) button was placed with ‘endothelial side up’ on a teflon block and few drops of corneal preservation medium (optisol) were placed over it such that the liquid reached the edge of CS rim. It was intentionally tried to keep tissue–teflon interface free of fluid to minimise tissue movement during donor harvesting. An 8.5 mm corneal trephine (Madhu instruments, Delhi, India) was stained with gentian violet at the edge and then used to make initial central partial thickness groove in CS button. The idea was to get a starting point to separate the DM from posterior stroma. The tip of a Sinskey hook (Madhu instruments, Delhi, India) was then used to create a cleft between DM and underlying stroma all around. At least 2–3 mm of DM lift was assured to help in holding for further separation. Subsequently, the edge of DM was held with one or two blunt suture tying forceps and gently pulled in direction parallel to endothelium and towards opposite edge. In one go, 20–30% of DM was separated. This was performed in each quadrant until the DM was separated from the stroma. It took 4–5 circles to separate the whole of DM. Simultaneous and 1
Myth exploded Figure 1 Composite of slit lamp images showing diffuse and slit images of the patient. (A) Diffuse illumination image showing central and inferior cornea oedema at presentation; (B) postoperative day 1 photograph after Descemet membrane endothelial keratoplasty (DMEK) showing reduction in corneal oedema and an anterior chamber filled half with air bubble; (C) diffuse and (D) slit views at postoperative 3 weeks showing inferior corneal oedema with Descemet endothelial complex (DEC) separation; and (E) diffuse and (F) slit views at postoperative 2 months after air descemetopexy was performed showing an attached DMEK DEC with an overlying clear cornea.
coordinated movements of both hands were performed when the edge of DM was held with two forceps. Also, it was ensured to keep the DM in corneal preservation medium all the time. After completion of DM stripping, it was left on the donor tissue with corneal preservation medium over DM until its injection into the eye.
Recipient preparation The surgery was performed in peribulbar anaesthesia. Epithelium was removed to improve the visibility. DM was stripped under AC maintainer as performed during routine DSEK.8 A small peripheral iridotomy was performed at 6 o’clock position using an automated vitrector. Finally, the AC maintainer was removed and paracentesis wound was hydrated.
solution drop by drop from the edge of CS rim and avoid direct instillation on endothelium. After staining, a small central tear of around 1×2.5 mm was noticed in DM (figure 2A). Since the tear had a flap attached at one end, it was decided to continue with the surgery. During washing of dye with BSS, the DEC got rolled up spontaneously with the endothelium at the outer side. It was aspirated into a customised injector mounted on a 2 mL syringe. The customised DEC injector was prepared from routine Akreos (Bausch & Lomb, USA) IOL injector (figure 2B,C). The injector was cut from proximal end and attached to a silicon tube used for phacoemulsification. Hence a ‘no-touch’ technique was used for donor insertion into the eye. Before injecting the DEC into the eye, AC was decompressed by tapping the posterior lip of paracentesis wound. DEC was injected into the AC with one push.
Donor injection The harvested DEC was stained with trypan blue 0.06% (Auroblue, Aurolab, Madurai, India) to improve visualisation of DEC inside the eye. It was ensured to instil dye or balanced salt 2
Donor unfolding The graft was oriented with the endothelial side down (donor DM facing recipient posterior stroma) onto the recipient Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
Myth exploded Figure 2 (A) Intraoperative photograph showing a central tear in the Descemet endothelial complex (DEC) during donor preparation. (B and C) the customised DEC injector.
posterior stroma by careful, indirect manipulation of the tissue with air and fluid. Fluid waves from the side ports and intermittent decompression of side ports along with repeated tapping on the corneal surface helped in DEC unfolding. While unfolding, the edges of DM folds should face the corneal stroma and not the iris (video 1). Once the proper direction of unfolding was confirmed, a small air bubble was injected below the DEC.
Surface strokes (and not massage) were used to unfold it further. Finally, a large air bubble was used and AC was filled completely with air. An air tight globe was achieved and maintained since an inferior peripheral iridotomy had been performed. Topical 5% povidone iodine, homatropine 2% and prednisolone forte 1% eye drops were instilled and the eye was patched.
Figure 3 Anterior segment optical coherence tomography pictures of the inferior cornea on (A) postoperative day 1 showing an attached Descemet membrane endothelial keratoplasty (DMEK) graft; (B) on postoperative day 6 when a thin Descemet membrane separation was seen; (C) at postoperative week 3 when the DMEK separation had increased with overlying corneal oedema; and (D) 1 month after successful repeat air injection was performed showing an attached DMEK graft with a clear overlying cornea.
Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
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Figure 4 Macular Optical Coherance Tomograohy scan showing cystoids macular edema, cause for a decreased visual acuity despite clear cornea.
DIFFERENTIAL DIAGNOSIS The history of cataract surgery along with corneal oedema on examination clinched the clinical diagnosis of pseudophakic bullous keratopathy. A suspicion of Fuchs endothelial dystrophy was ruled out by the normal specular endothelial counts in the other eye.
TREATMENT The patch was opened after 2 h and an attached DM was confirmed on slit lamp. It was confirmed whether the air bubble was above iridectomy. The patient was prescribed topical prednisolone 1% two hourly, moxifloxacin 0.5% four times per day and homatropine 2% two times per day.
INVESTIGATIONS The attached DEC was confirmed with anterior segment optical coherence tomography (AS-OCT: Carl Zeiss Meditec, USA; 4
figure 3A). However, on sixth postoperative day, a small fluid pocket was observed between the DEC and the posterior host stroma in inferior third of the graft area (figure 3B). When the patient presented subsequently after 2 weeks, the inferior DEC detachment had increased with overlying corneal oedema (figure 3C). One month after descemetopexy, the DEC was attached with a clear overlying cornea (figure 3D).
OUTCOME AND FOLLOW-UP On first postoperative day, DEC was attached with reduction in the overlying corneal oedema and air bubble filling half of AC (figure 1B). The attached DEC was confirmed with AS-OCT (Carl Zeiss Meditec, USA; figure 3A). The central DEC tear was not noticed at this examination. The patient was discharged on topical antibiotics and steroids. On sixth postoperative day, a small fluid pocket was observed between the DEC and the posterior host stroma in inferior third of the graft area (figure 3B). Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
Myth exploded
Figure 5 Specular photo-micrograph showing the endothelial cell count of 1580 cells/mm2 at 2 months follow-up. As the detachment was very small, it was decided to observe it for spontaneous attachment.9 However, when the patient presented after 2 weeks, the inferior DEC detachment had increased with overlying corneal oedema (figure 1C,D) which was also confirmed on AS-OCT (figure 3C). Descemetopexy with 100% air was performed the same day which reattached the DEC. Subsequently, DEC remained attached and at the last follow-up of 2 months, DEC was well opposed with a clear overlying cornea (figures 1E,F and 3D). The final BCVA was 20/ 60. The reason for low visual acuity was associated cystoid macular oedema (figure 4). Specular count at 2 months postoperative period was 1580 cells/mm2 (figure 5).
DISCUSSION DMEK involves stripping of an intact DM from the graft stroma, its insertion into the host AC and its attachment to the host stroma.1 Each step is technically demanding due to the thin and delicate nature of the DM which is prone to damage at every step.4 Although various modifications have been tried in lenticule preparation,10 tissue loss remains a significant concern especially in hands of less experienced surgeons. Guerra et al,3 in their series of 136 eyes, have reported tissue loss in 4.2% of cases. Tourtas et al reported a series of three patients in which the DM was accidentally torn into two pieces during graft preparation. However, both pieces of DEC complex could be successfully implanted into the AC with good outcomes at 6 months.7 We performed DMEK in a 70-year-old man diagnosed with pseudophakic bullous keratopathy. During lenticule preparation, we noticed a small central tear in the DM endothelial complex. This was probably due to the learning curve of the surgeon (VM) which in the case of DMEK has been reported to be steep.11 While Price et al12 have reported a tissue wastage of 8% in a series of 66 eyes, Tourtas et al attained successful outcomes after implantation in three cases in which the DEC had been completely torn into two pieces. They, however, required a repeat air injection in each case.7 In our case, the central tear in DEC was Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
small in area and had a flap attached at one side. The flap was likely to attach with air at a desired position and the surgery was continued. The decision to continue was also based on the reports of successful spontaneous attachments of detached DM after cataract surgery.13 Also, the option of repeating the endothelial keratoplasty early, if DMEK failed, was kept in mind. On postoperative day 1, we found an attached DM endothelial complex with air filling half of the AC. However, on postoperative day 6, partial separation of the DMEK graft was noticed with an overlying corneal oedema. Earlier reports on spontaneous attachments of DMEK lenticule9 and re-endothelialisation of the recipient posterior stroma occurring as early as 5 weeks exist.14 Also, the corneal oedema has been reported to spontaneously clear in presence of partial detachment from periphery inwards.15 Our patient, however, had a small hole in the otherwise attached DMEK surrounding it. Hence, a decision against intervention was made. The patient was, however, advised to lie down in supine position as reported earlier.14
Video 1 The surgery. 5
Myth exploded Subsequently, at 3 weeks postoperatively, the corneal oedema had increased to involve a larger inferior area and DMEK graft detachment was observed in the corresponding area. Repeat air injection for detached DMEK graft is well known. It was required in 38 eyes (63%) in the series reported by Price et al12 and was successful. Descemetopexy was hence performed with air and was successful in attachment of the graft in our case. Subsequently, the DMEK complex remained attached to the posterior stroma, the overlying oedema gradually cleared, visual acuity improved at 2 months follow-up and the tear in the DMEK DEC was unnoticeable. The endothelial cell loss at the end of 2 months was 25.5%, which is less than the reported endothelial cell loss at 6 months.1 Though the follow-up is limited, most of the DMEK detachments and the endothelial cell loss post-DMEK are known to occur in the intraoperative and the early postoperative period.14 15 Hence, the graft is expected to remain attached and function adequately in future. The pertinent query in our case was to assess the possible reason of graft detachment. Dirisamer et al14 have defined clinically significant graft detachment post-DMEK as a lack of adherence of the donor DM to the recipient posterior stroma, reducing visual outcome and/or necessitating a secondary intervention. Partial detachments are known to be more common.14 15 Dirisamer et al14 reported the graft detachment rate of 24% post-DMEK, 12% being clinically significant. Various factors have been shown to influence graft detachment post-DMEK like the area of DM stripping less than the DMEK DEC and hence an overlap and the use of viscoelastic instead of air for descemetorhexis.14 15 Another significant factor which contributes to the DMEK detachment is the status of the air fill at the completion of the surgery. While Dirisamer et al,14 15 Kruse et al5 and Liarakos et al16 recommend sufficient air bubble for 45–60 min, Price et al12 performed an inferior peripheral iridotomy during each case, with AC 90% filled with air at the end of surgery and checked each patient an hour or two afterwards to ensure patency of the iridotomy. Other reasons reported for DMEK graft detachment are inward folds of DMEK graft which tend to roll away, further increasing the area of detachment, in sufficient air fill in a vitrectomised eye, insertion of upside-down graft irido-graft synechiae, poor endothelial morphology and stromal irregularity under the main incision.14 DMEK detachments are most commonly seen in the inferior DMEK graft due to the persistence of the air bubble in the superior quadrant for a longer period of time as was seen in our case.14 The detachment of the DMEK DEC in our case could either be due to the iatrogenic DM tear created during DEC preparation or it could be due to the routine high DMEK graft
Learning points ▸ Descemet membrane endothelial keratoplasty (DMEK) is a technically demanding surgery with a steep learning curve. ▸ Tissue loss is common with DMEK. It, however, decreases with the increasing experience of the surgeon. ▸ A small tear in the Descemet endothelial complex does not necessitate tissue replacement. ▸ Good anatomical and visual outcome can be achieved even in cases with a torn DMEK graft.
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detachment rates, which is reported as high as 82% (31/38 eyes, Tourtas et al).2 It has also been reported that DMEK graft required significantly higher number of air injections for attachment when tissues preserved in optisol-GS medium were used as compared with organ culture-stored donors. The tissue used in our patient had also been stored in optisol medium.17 However, detachment of a previously attached DMEK graft made us to believe that the detachment could have occurred due to the gradual seepage of the aqueous through the flap hole. Contributors RJ and VM performed the literature review, analyzed the data and wrote the manuscript. RJ, VM and RM were responsible for the conception of the article and design. RM and VSS revised the article critically for important intellectual content. Competing interests None. Patient consent Obtained. Provenance and peer review Not commissioned; externally peer reviewed.
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Anshu A, Price MO, Tan DTH, et al. Endothelial keratoplasty: a revolution in evolution. Surv Ophthalmol 2012;57:236–52. Tourtas T, Laaser K, Bachmann BO, et al. Descemet membrane endothelial keratoplasty versus descemet stripping automated endothelial keratoplasty. Am J Ophthalmol 2012;153:1082–90. Guerra FP, Anshu A, Price MO, et al. Descemet’s membrane endothelial keratoplasty: prospective study of 1-year visual outcomes, graft survival, and endothelial cell loss. Ophthalmology 2011;118:2368–73. Patel SV. Graft survival and endothelial outcomes in the new era of endothelial keratoplasty. Exp Eye Res 2012;95:40–7. Kruse FE, Laaser K, Cursiefen C, et al. A stepwise approach to donor preparation and insertion increases safety and outcome of Descemet membrane endothelial keratoplasty. Cornea 2011;30:580–7. Tourtas T, Heindl LM, Kopsachilis N, et al. Use of accidentally torn descemet membrane to successfully complete Descemet membrane endothelial keratoplasty. Cornea 2013;32:1418–22. Jain R, Murthy SI, Basu S, et al. Anatomical and visual outcomes of descemetopexy in post cataract surgery Descemet’s membrane detachment. Ophthalmology 2013;120:1366–72. Mittal V, Mittal R, Sangwan VS. Successful Descemet stripping endothelial keratoplasty in congenital hereditary endothelial dystrophy. Cornea 2011;30:354–6. Balachandran C, Ham L, Verschoor CA, et al. Spontaneous corneal clearance despite graft detachment in Descemet membrane endothelial keratoplasty. Am J Ophthalmol 2009;148:227–34. Dapena I, Ham L, Droutsas K, et al. Learning curve in Descemet’s membrane endothelial keratoplasty: first series of 135 consecutive cases. Ophthalmology 2011;118:2147–54. Price MO, Price FW Jr. Descemet’s membrane endothelial keratoplasty surgery: update on the evidence and hurdles to acceptance. Curr Opin Ophthalmol 2013;24:329–35. Price MO, Giebel AW, Fairchild KM, et al. Descemet’s membrane endothelial keratoplasty: prospective multicenter study of visual and refractive outcomes and endothelial survival. Ophthalmology 2009;116:2361–8. Minkovitz JB, Schrenk LC, Pepose JS. Spontaneous resolution of an extensive detachment of Descemet’s membrane following phacoemulsification. Arch Ophthalmol 1994;112:551–2. Dirisamer M, van Dijk K, Dapena I, et al. Prevention and management of graft detachment in Descemet membrane endothelial keratoplasty. Arch Ophthalmol 2012;130:280–91. Dirisamer M, Dapena I, Ham L, et al. Patterns of corneal endothelialization and corneal clearance after Descemet membrane endothelial keratoplasty for Fuchs endothelial dystrophy. Am J Ophthalmol 2011;152:543–55. Liarakos VS, Dapena I, Ham L, et al. Intraocular graft unfolding techniques in Descemet membrane endothelial keratoplasty. Arch Ophthalmol 2013;131:29–35. Laaser K, Bachmann BO, Horn FK, et al. Donor tissue culture conditions and outcome after Descemet membrane endothelial keratoplasty. Am J Ophthalmol 2011;151:1007–18.
Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
Myth exploded
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Mittal V, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202935
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