| MP 9.03.22 | Endothelial Keratoplasty | |
| Medical Policy | ||
| Section Other |
Original Policy Date 08:2009 |
Last Review Status/Date Created with literature review/08:2009 |
| Issue 8:2009 |
Return to Medical Policy Index |
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Description
Endothelial keratoplasty (EK), also referred to as posterior lamellar keratoplasty, is a form of corneal transplantation in which the diseased inner layer of the cornea, the endothelium, is replaced with healthy donor tissue. Specific techniques include Descemet’s stripping endothelial keratoplasty, Descemet’s stripping automated endothelial keratoplasty, or Descemet’s membrane endothelial keratoplasty.
The cornea, a clear, dome-shaped membrane that covers the front of the eye, is a key refractive element of the eye. Layers of the cornea consist of the epithelium (outermost layer); Bowman’s layer; the stroma, which comprises approximately 90% of the cornea; Descemet’s membrane; and the endothelium. The endothelium removes fluid from the stroma and limits its entry, thereby maintaining the ordered arrangement of collagen and preserving the cornea’s transparency. Diseases that affect the endothelial layer include Fuchs’ endothelial dystrophy, aphakic and pseudophakic bullous keratopathy (corneal edema following cataract extraction), and failure or rejection of a previous corneal transplant.
The established surgical treatment for corneal disease is penetrating keratoplasty (PK), which involves the creation of a large central opening through the cornea and then filling the opening with full-thickness donor cornea that is sutured in place. Visual recovery after PK may take a year or more due to slow wound healing of the avascular full-thickness incision, and the procedure frequently results in irregular astigmatism due to the sutures and the full-thickness vertical corneal wound. PK is associated with an increased risk of wound dehiscence, endophthalmitis, and total visual loss after relatively minor trauma for years after the index procedure. There is also risk of severe, sight-threatening complications such as expulsive suprachoroidal hemorrhage, in which the ocular contents are expelled during the operative procedure, as well as postoperative catastrophic wound failure.
A number of related techniques have been, or are being, developed to selectively replace the diseased endothelial layer. One of the first endothelial keratoplasty (EK) techniques was termed deep lamellar endothelial keratoplasty (DLEK), which used a smaller incision than PK, allowed more rapid visual rehabilitation, and reduced postoperative irregular astigmatism and suture complications. Modified EK techniques include endothelial lamellar keratoplasty, endokeratoplasty, posterior corneal grafting, and microkeratome-assisted posterior keratoplasty. Most frequently used at this time are Descemet’s stripping endothelial keratoplasty (DSEK), which uses hand-dissected donor tissue, and Descemet’s stripping automated endothelial keratoplasty (DSAEK), which uses an automated microkeratome to assist in donor tissue dissection. These techniques include some donor stroma along with the endothelium and Descemet’s membrane, which results in a thickened stromal layer after transplantation. If the donor tissue comprises Descemet’s membrane and endothelium alone, the technique is known as Descemet’s membrane endothelial keratoplasty (DMEK). By eliminating the stroma on the donor tissue and possibly reducing stromal interface haze, DMEK is considered to be a potential improvement over DSEK/DSAEK.
EK involves removal of the diseased host endothelium and Descemet’s membrane with special instruments through a small peripheral incision. A donor tissue button is prepared from corneoscleral tissue after removing the anterior donor corneal stroma by hand (e.g., DSEK) or with the assistance of an automated microkeratome (e.g., DSAEK). Several microkeratomes have received clearance for marketing through the U.S. Food and Drug Administration (FDA) 510(k) process. Donor tissue preparation may be performed by the surgeon in the operating room, or by the eye bank and then transported to the operating room for final punch out of the donor tissue button. To minimize endothelial damage, the donor tissue must be carefully positioned in the anterior chamber. An air bubble is frequently used to center the donor tissue and facilitate adhesion between the stromal side of the donor lenticule and the host posterior corneal stroma. Repositioning of the donor tissue with application of another air bubble may be required in the first week if the donor tissue dislocates. The small corneal incision is closed with one or more sutures, and steroids or immunosuppressants may be provided either topically or orally to reduce the potential for graft rejection. Visual recovery following EK is typically achieved in 4-8 weeks, in comparison with the year or more that may be needed following PK.
Eye Bank Association of America (EBAA) statistics show the number of EK cases in the United States increased from 1,398 in 2005 to 14,159 in 2007. (1) About 1/3 of corneal transplants performed in the United States were EK procedures, and EK was performed for over 85% of patients with endothelial disease.
As with any new surgical technique, questions have been posed about long-term efficacy and the risk of complications. EK-specific complications include graft dislocations, endothelial cell loss, and rate of failed grafts. Also of interest is the impact of the surgeon’s learning curve on the risk of complications.
Policy
Endothelial keratoplasty (Descemet’s stripping endothelial keratoplasty or Descemet’s stripping automated endothelial keratoplasty) may be considered medically necessary for the treatment of endothelial dysfunction, including but not limited to Fuchs’ endothelial dystrophy, aphakic and pseudophakic bullous keratopathy, and failure or rejection of a previous corneal transplant.
Policy Guidelines
Endothelial keratoplasty should not be used in place of PK for conditions with concurrent endothelial disease and anterior corneal disease. These situations would include concurrent anterior corneal dystrophies, anterior corneal scars from trauma or prior infection, and ectasia after previous laser vision correction surgery. EK should be performed by surgeons who are adequately trained and experienced in the specific techniques and devices used.
Since January 2009, there have been specific CPT codes for this procedure and any associated backbench preparation of the allograft: 65756 Keratoplasty (corneal transplant); endothelial65757 Backbench preparation of corneal endothelial allograft prior to transplantation (List separately in addition to code for primary procedure)
Benefit Application
BlueCard/National Account Issues
State or federal mandates (e.g., FEP) may dictate that all FDA-approved devices, drugs or biologics may not be considered investigational and thus these devices may be assessed only on the basis of their medical necessity.
Rationale
Literature Review
Descemet’s Stripping Endothelial Keratoplasty and Descemet’s Stripping Automated Endothelial Keratoplasty (DSEK/DSAEK) A 2009 review of the safety and efficacy of DSAEK, performed by the American Academy of Ophthalmology’s (AAO) Ophthalmic Technology Assessment Committee, identified 1 level I study (randomized controlled trial of precut vs. surgeon dissected) along with 9 level II (well-designed observational studies) and 21 level III studies (mostly retrospective case series). (2) Although more than 2,000 eyes treated with DSAEK were reported on in different publications, most were reported by one research group with some overlap in patients. The main results from this evidence review are as follows:- DSAEK-induced hyperopia ranged from 0.9 to 1.5 diopters (D), with minimal induction of astigmatism (ranging from 0 to 0.6 D).
- The reporting of visual acuity was not standardized in the studies reviewed. The average best-corrected visual acuity (BCVA) ranged from 20/33 to 20/66, and the percentage of patients seeing 20/40 or better ranged from 38% to 100%.
- The most common complication from DSAEK in the studies reviewed was posterior graft dislocation (mean 14%; range 0 –82%), with a lack of adherence of the donor posterior lenticule to the recipient stroma, typically occurring within the first week. It was noted that this figure may be skewed by multiple publications from one research group with low complication rates. Graft dislocation required additional surgical procedures (rebubble procedures) but did not lead to sight-threatening vision loss in the articles reviewed.
- Endothelial graft rejection occurred in an average 10% of patients (range, 0 –45%); most were reversed with topical or oral immunosuppression, with some cases progressing to graft failure. Primary graft failure, defined as unhealthy tissue that has not cleared within 2 months, occurred in 5% of patients (range 0 –29%). Iatrogenic glaucoma occurred in an average of 3% of patients (range 0 –15%) due to a pupil block induced from the air bubble in the immediate postoperative period or delayed glaucoma from topical corticosteroid side effects.
- Endothelial cell loss, which provides an estimate of long-term graft survival, was an average 37% at 6 months and 42% at 12 months. This percentage of cell loss was reported to be similar to that observed with PK
“Future research should be directed at assessing better surgical techniques for increasing endothelial cell survival with endothelial procedures, whether this represents new surgical techniques and/or new instrumentation…. Both new surgical techniques such as Descemet’s membrane endothelial keratoplasty and new insertion techniques must be validated by basic laboratory ex vivo studies and large, well-designed cohort or randomized controlled studies and/or long-term prospective studies demonstrating complication rates and long-term endothelial cell survival.” A number of studies included in the AAO review were from Chen, Terry, and colleagues at the Devers Eye Institute. One of the publications reported 6-month clinical outcomes from 100 of the first 150 consecutive eyes treated by DSAEK at this tertiary care center during 2005 and 2006. (3) Fifty eyes were not available for 6-month follow-up due to illness, death, or residence out of state. Preoperatively, every patient had a diagnosis of endothelial dysfunction with clinically evident stromal edema; BCVA averaged 20/86 and uncorrected visual acuity (UCVA) averaged 20/155. Cataract surgery (n = 51) was concurrently performed if the patient had visually significant cataract or mild cataract with expectation of progression and minimal remaining accommodative amplitude. At 6-month follow-up all grafts were clear and there were no primary graft failures. There was an average gain of >4 Snellen lines with an average BCVA of 20/38. Eighty-five percent of eyes had better visual acuity than they had preoperatively, and 81% obtained vision of 20/40 or better. When patients were excluded due to other possible causes of visual loss such as macular or glaucomatous damage, BCVA improved from 20/60 to 20/30 (n =74), with an average gain of 3 Snellen lines. Eighty-eight percent of eyes in this group had better visual acuity at 6 months than they had preoperatively, and 97% of eyes had obtained a vision of 20/40 or better. The reporting of results on visual acuity did not distinguish between patients who had received concurrent cataract surgery and those whose improvements could be attributed entirely to DSAEK. A search of the MEDLINE database, performed to identify additional reports published after the AAO technology assessment, identified several case reports on complications (e.g., epithelial ingrowth and adverse effects of the bubbles) as well as a number of papers on DSEK/DSAEK technique. Chen and colleagues reported the effect of training on outcomes following DSAEK. (4) Of 327 consecutive cases performed at their tertiary care centers during 2005–2007, 235 were performed by the attending corneal surgeon and 92 were performed by the corneal fellows. Loss to follow-up at 6 months (36% to 37%) was due to illness, death, or residence out of state. For the 208 patients who returned for the 6-month assessment, 91% of those treated by the attending surgeon and 69% of those treated by fellows had alsoundergone concurrent phacoemulsification for visually significant cataract at the time of DSAEK. There were no graft failures in either group, and all grafts were clear at the 6-month assessment. Dislocations and endothelial cell loss were similar in the 2 groups of patients (2% vs.1% dislocations and mean cell loss of 32% and 35%). Patients from both groups gained about 4 Snellen lines, with a 6-month average best corrected visual acuity of 20/37 and 20/36. Vision of 20/40 or better was obtained by 78% of patients treated by attending surgeons and 90% of patients treated by fellows. Vision of 20/20 or better was obtained by 14% of patients treated by attending surgeons and 3% treated by fellows. Descemet’s Membrane Endothelial Keratoplasty (DMEK) Recent reviews suggest that by eliminating the stroma on the donor tissue, DMEK may reduce stromal interface haze and provide better visual acuity outcomes than DSEK/DSAEK. (5, 6) Current literature is limited, although a review of the first 50 consecutive cases from a group in Europe suggests that a greater number of patients achieve 20/25 vision or better with DMEK. (7) Of the 50 consecutive eyes, 10 (20%) required a secondary DSEK for failed DMEK. For the remaining 40 eyes, 95% had a best-corrected visual acuity of 20/40 or better and 75% had a best-corrected visual acuity of 20/25 or better. Donor detachments and primary graft failure with DMEK remain problematic, and the ultimate success of DMEK depends on the reliability of graft adherence and demonstrated improvement in visual acuity outcomes in comparison with DSAEK. Clinical Input Received through Physician Specialty Societies and Academic Medical Centers In response to requests, input was received through physician specialty societies (3 reviewers representing 3 associated organizations) and 2 academic medical centers while this policy was under review. While the various physician specialty societies and academic medical centers may collaborate with and make recommendations during this process, through the provision of appropriate reviewers, input received does not represent an endorsement or position statement by the physician specialty societies or academic medical centers, unless otherwise noted. Clinical input supported DSEK and DSAEK as the standard of care for endothelial failure, due to improved outcomes in comparison with penetrating keratoplasty. Summary Endothelial keratoplasty, and particularly DSEK and DSAEK, are relatively new procedures. The literature and clinical input available at this time indicates that endothelial keratoplasty reduces the serious complications associated with penetrating keratoplasty. Specifically, visual recovery occurs much earlier, and because EK maintains an intact globe without a sutured donor cornea, astigmatism and the risk of severe, sight-threatening complications such as expulsive suprachoroidal hemorrhage and postoperative catastrophic wound failure are eliminated. These improvements appear to have resulted in rapid acceptance of this procedure with a trend toward intervention at an earlier stage of endothelial disease. Long-term graft survival with these new techniques is presently unknown. However, current procedures result in acceptable short-term survival, and additional surgical intervention can be performed with a low risk of visual loss. Due to the marked reduction in serious complications compared to the alternative, DSEK/DSAEK has become the preferred approach for endothelial dysfunction among corneal surgeons. Therefore, these techniques may be considered medically necessary. EK will continue to evolve as techniques are modified in an attempt to improve donor tissue adherence and increase endothelial survival. Randomized controlled studies and/or long-term prospective studies will be needed to adequately evaluate these new procedures. Technology Assessments, Guidelines and Position Statements In 2009, the Health Policy Committee of the American Academy of Ophthalmology (AAO) published a position paper on endothelial keratoplasty, stating that the optical advantages, speed of visual rehabilitation, and lower risk of catastrophic wound failure have driven the adoption of EK as the standard of care for patients with endothelial failure and otherwise healthy corneas. (8) The AAO position paper was based in large part on a comprehensive review of the literature on Descemet’s stripping automated endothelial keratoplasty (DSAEK) by the American Academy of Ophthalmology’s Ophthalmic Technology Assessment Committee. (2) The Technology Assessment Committee concluded that “the evidence reviewed suggests DSAEK appears safe and efficacious for the treatment of endothelial diseases of the cornea. Evidence from retrospective and prospective DSAEK reports described a variety of complications from the procedure, but these complications do not appear to be permanently sight threatening or detrimental to the ultimate vision recovery in the majority of cases. Long-term data on endothelial cell survival and the risk of late endothelial rejection cannot be determined with this review.” “DSAEK should not be used in lieu of PK for conditions with concurrent endothelial disease and anterior corneal disease. These situations would include concurrent anterior corneal dystrophies, anterior corneal scars from trauma or prior infection, and ectasia after previous laser vision correction surgery.” The United Kingdom’s National Institute for Health and Clinical Excellence released guidance on corneal endothelial transplantation in 2009. (9) The studies reviewed used DLEK, DSEK, and DSAEK. Additional data reviewed from the UK Transplant Register showed lower graft survival rates after EK than after PK; however, the difference in graft survival between the two procedures was noted to be narrowing with increased experience in EK use. The guidance concluded that “current evidence on the safety and efficacy of corneal endothelial transplantation (also know as endothelial keratoplasty [EK]) is adequate to support the use of this procedure provided that normal arrangements are in place for clinical governance and consent.” The Committee noted that techniques for this procedure continue to evolve, and thorough data collection should continue to allow future review of outcomes. Medicare National Coverage No national coverage determination References:
- Eye Bank Association of America. 2007 Eye banking statistical report. Available at: http://www.restoresight.org/.
- American Academy of Ophthalmology Ophthalmic Technology Assessment Committee Cornea and Anterior Segment Disorders Panel. Safety and efficacy of Descemet’s stripping automated endothelial keratoplasty (DSAEK). Ophthalmology, 2009, in press.
- Chen ES, Terry MA, Shamie N et al. Descemet-stripping automated endothelial keratoplasty: six-month results in a prospective study of 100 eyes. Cornea 2008; 27(5):514-20.
- Chen ES, Terry MA, Shamie N et al. Endothelial keratoplasty: vision, endothelial survival, and complications in a comparative case series of fellows vs attending surgeons. Am J Ophthalmol 2009; 148(1):26-31.e2.
- Dapena I, Ham L, Melles GR. Endothelial keratoplasty: DSEK/DSAEK or DMEK--the thinner the better? Curr Opin Ophthalmol 2009; 20(4):299-307.
- Rose L, Kelliher C, Jun AS. Endothelial keratoplasty: historical perspectives, current techniques, future directions. Can J Ophthalmol 2009; 44(4):401-5.
- Ham L, Dapena I, van Luijk C et al. Descemet membrane endothelial keratoplasty (DMEK) for Fuchs endothelial dystrophy: review of the first 50 consecutive cases. Eye. 2009 Jan 30. [Epub ahead of print]
- American Academy of Ophthalmology Health Policy Committee Position Paper on Endothelial Keratoplasty, January 29, 2009.
- National Institute for Health and Clinical Excellence. Corneal endothelial transplantation. Available at: http://www.nice.org.uk/nicemedia/pdf/IPG304Guidance.pdf. Last viewed July 2009.
Codes |
Number |
Description |
| CPT | 65756 | Keratoplasty (corneal transplant); endothelial |
| 65757 | Backbench preparation of corneal endothelial allograft prior to transplantation (List separately in addition to code for primary procedure) | |
| ICD-9 Diagnosis | 371.23 | Bullous keratopathy |
| 371.57 | Endothelial corneal dystrophy | |
| 996.51 | Mechanical complication due to corneal graft |
Descemet’s membrane endothelial keratoplasty (DMEK)
Descemet’s stripping endothelial keratoplasty (DSEK)
Descemet’s stripping automated endothelial keratoplasty (DSAEK)
Endothelial keratoplasty (EK)
Penetrating keratoplasty (PK)
Policy History
| Date | Action | Reason |
| 08/13/09 | New policy; add to Miscellaneous/Other Section; vision Subsection | Policy created with literature search through June 2009; DSEK/DSAEK considered medically necessary |
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