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MP 9.03.01 Keratoprosthesis

Medical Policy    
Miscellaneous Policies 
Original Policy Date
Last Review Status/Date
Reviewed with literature search/2:2014
  Return to Medical Policy Index


Our medical policies are designed for informational purposes only and are not an authorization, or an explanation of benefits, or a contract.  Receipt of benefits is subject to satisfaction of all terms and conditions of the coverage.  Medical technology is constantly changing, and we reserve the right to review and update our policies periodically. 


A keratoprosthesis is an artificial cornea that is intended to restore vision to patients with severe bilateral corneal disease (suchas prior failed corneal transplants, chemical injuries, or certain immunologic conditions)for whom a corneal transplant is not an option.


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 established surgical treatment for corneal disease is penetrating keratoplasty (PK), which involves making a large central opening through the cornea and then filling the opening with full-thickness donor cornea. In certain conditions, such as Stevens-Johnson syndrome; cicatricial pemphigoid; chemical injury; or prior failed corneal transplant, survival of transplanted cornea is poor. The keratoprosthesis has been developed to restore vision in patients for whom a corneal transplant is not an option.

Keratoprosthetic devices consist of a central optic held in a cylindrical frame. The keratoprosthesis replaces the section of cornea that has been removed, and, along with being held in place by the surrounding tissue, may be covered by a membrane to further anchor the prosthesis. A variety of biologic materials are being investigated to improve the integration of prosthetic corneal implants into the stroma and other corneal layers.

Autologous keratoprostheses use a central polymethylmethacrylate (PMMA) optic supported by a skirt of either tibia bone or the root of a tooth with its surrounding alveolar bone. The most common is the osteo-odonto keratoprosthesis (OOKP), which uses osteodental lamina derived from an extracted tooth root and attached alveolar bone that has been removed from the patient’s jaw. Insertion of the OOKP device requires a complex staged procedure, in which the cornea is first covered with buccal mucosa. The prosthesis itself consists of a PMMA optical cylinder, which replaces the cornea, held in place by a biological support made from a canine tooth extracted from the recipient. A hole is drilled through the dental root and alveolar bone, and the PMMA prosthesis is placed within. This entire unit is placed into a subcutaneous ocular pocket and is then retrieved 6 to 12 months later for final insertion.

Hydroxyapatite, with a similar mineral composition to both bone and teeth (phosphate and calcium), may also be used as a bone substitute and as a bioactive prosthesis with the orbit. Collagen coating and scaffolds have also been investigated to improve growth and biocompatibility with the cornea epithelial cells, which form the protective layer of the eye. Many of these materials and devices are currently being tested in vitro or in animal models.

Regulatory Status

A keratoprosthesis is a Class II U.S. Food and Drug Administration (FDA) device intended to provide a transparent optical pathway through an opacified cornea, in an eye that is not a reasonable candidate for a corneal transplant. Two permanent keratoprostheses have received 510(k) marketing clearance by FDA. The Dohlman-Doane Keratoprosthesis, also referred to as the Boston Keratoprosthesis (KPro), is manufactured under the auspices of the Harvard Medical School-affiliated Massachusetts Eye and Ear Infirmary. The Boston type I KPro uses an optic between a central stem and a back plate. The Boston type II prosthesis is a modification of the type I prosthesis and is designed with an anterior extension to allow implantation through surgically closed eyelids. The AlphaCor, previously known as the Chirila keratoprosthesis (Chirila KPro) marketed by Argus Biomedical was cleared for marketing by FDA in 2002. The AlphaCor prosthesis consists of a PMMA device with a central optic region fused with a surrounding sponge skirt; the device is inserted in a 2-stage surgical procedure. According to the 510(k) summary, the AlphaCor keratoprosthesis was shown to be substantially equivalent to the Dohlman-Doane Type I Keratoprosthesis. Both devices are indicated as permanent implantable keratoprostheses for eyes that are not corneal transplant candidates and are made of materials that have been proven to be biocompatible.


The Boston Keratoprosthesis (Boston KPro) may be considered medically necessary for the treatment of corneal blindness under the following conditions:

  • The cornea is severely opaque and vascularized; AND
  • The patient has had two or more prior failed corneal transplants.

Patients should be expected to be able to be compliant with postoperative care.

A permanent keratoprosthesis for all other conditions is considered investigational.

All other types of permanent keratoprostheses are considered investigational

Policy Guidelines

Implantation of a keratoprosthesis is considered a high-risk procedure associated with numerous complications and probable need for additional surgery. Therefore, the likelihood of regaining vision and the patient’s visual acuity in the contralateral eye should be taken into account when considering the appropriateness of this procedure. Treatment should be restricted to centers experienced in treating this condition and staffed by surgeons adequately trained in techniques addressing implantation of this device.

Benefit Application
BlueCard/National Account Issues

State or federal mandates (e.g., FEP) may dictate that all devices approved by the U.S. Food and Drug Administration may not be considered investigational, and thus these devices may be assessed only on the basis of their medical necessity.


This policy was created in 1996 and updated periodically with literature review since that time. The most recent update with literature review was performed through January 14, 2014.

The keratoprosthesis is intended for the relatively small number of patients with severe corneal damage who have lost vision and for whom a corneal transplant is not expected to result in satisfactory outcomes. This generally refers to the population of patients who have failed one or more corneal transplants and who therefore have very limited options to prevent blindness. Because this is considered to be a salvage procedure with no acceptable alternative treatment, comparative studies are limited/lacking. The available literature primarily consists of retrospective case series. This literature review examines the types of devices currently being tested in humans, focusing on reports that allow assessment of integration within the eye, durability, visual outcomes, and adverse events following implantation.

Literature Review

Osteo-odonto- keratoprosthesis

A systematic review from 2012 included 8 case series describing surgical outcomes and complication rates of the OOKP.(1) Sample sizes ranged from 4 to 181 eyes. (The 2 largest series are described next. The study by Hughes et al described next was not included in the systematic review.) At 5 years, the anatomic survival rate was 87.8% (range, 67%-100%), and at 20 years the anatomic survival rate was 81.0% (3 studies, range, 65%-98%). About half of the patients obtained visual acuity better than 6/18. Visual acuity in the other patients was not described.

The largest series is by Falcinelli et al in 2005, who reported on OOKP in 181 patients.(2) At a median follow-up of 12 years, survival analysis estimated that 18 years after surgery, the probability of retaining an anatomically intact OOKP was 85% with reasonable visual acuity.

In 2008, investigators from Spain published a retrospective review of 227 patients who underwent OOKP (n=145), or osteokeratoprosthesis (OKP, n=82) using tibial bone in patients who lacked canine teeth to assemble the prosthesis.(3) A second publication in 2011 from the same study examined the impact of clinical factors on long-term functional and anatomic outcomes.(4) The primary diagnosis was chemical or thermal burn (48%), Steven-Johnson syndrome or Lyell syndrome (13%), cicatricial pemphigoid (11%), trachoma (11%), and 17% other or not assignable. The mean preoperative decimal best-corrected visual acuity (BCVA) was 0.00062 (range: light perception to 0.10). (On the decimal visual acuity scale 0=no light perception, 0.00001=light perception, 0.0001=light projection, and 0.001=counting fingers.) Functional survival was defined as BCVA of 0.05 or more, and anatomic survival was defined as retention of the keratoprosthesis lamina. Mean follow-up was 8.4 years for OOKP and 3.5 years for OKP. Anatomic success at 10 years was estimated to be 66% for OOKP and 47% for OKP. Functional success at 10 years was estimated to be 38% for OOKP and 17% for OKP. The best functional survival was in the Stevens-Johnson group, followed by chemical burn and trachoma. The least favorable prognosis was for the thermal burn group. Complications included extrusion of the keratoprosthesis (28%), retinal detachment (16%), uncontrolled glaucoma (11%), infection (9%), retroprosthetic membrane (5%), and vitreous hemorrhage (3%). In cases without complications, functional survival was 57% at 5 years and 42% at 10 years.

Hughes et al reported vitreoretinal complications of the OOKP in a retrospective review of 35 cases performed at 1 hospital in England between 1996 and 2005.(5) Original diagnoses were Stevens-Johnson syndrome in 15 patients, chemical injury in 5, mucous membrane pemphigoid in 3, and topical medication toxicity in 3. Follow-up at a mean 57 months (range, 13 to 105 months) revealed 9 vitreoretinal complications in 8 patients (23%). These included vitreous hemorrhage (n=3), rhegmatogenous retinal detachment (n=3), retinal detachment complicating endophthalmitis after lamina resorption and optic extrusion (n=2), and intraoperative choroidal hemorrhage (1 patient). Retinal detachment with loss of vision occurred in 5 of the 8 patients. A 2009 publication of 36 patients treated at the same hospitals between 1996 and 2006 (likely to be an overlap of the patients reported by Hughes et al(5)) estimated that the probability of retaining visual acuity was 53% at 5 years and 44% at 9 years.(6) In addition to the vitreoretinal complications causing loss of vision, resorption of the bony lamina to the extent of causing visual or anatomic compromise occurred in 7 cases (19%).

Boston Keratoprosthesis (KPro or Dohlman-Doane)

The largest study on the Boston KPro is a prospective series of 265 eyes (265 patients) from 18 medical centers, published by the Boston Type 1 Keratoprosthesis Study Group in 2012.(7) The objective of this analysis was to evaluate the time to development of retroprosthetic membranes. Most eyes (85.4%) had undergone an average of 2.2 (range, 1 to 8) penetrating keratoplasties before keratoprosthesis implantation. The remaining eyes (14.6%) were considered to be at high risk for penetrating keratoplasty failure and had received a primary keratoprosthesis. At a mean of 17.8 months of follow-up, retroprosthetic membranes had formed in 31.7% of eyes. The mean time to development of retroprosthetic membranes was 216.7 days (range, 7 days to 4 years). Risk factors were found to be the indication for the keratoprosthesis, specifically, infectious keratitis had a hazard ratio of 3.20, and aniridia had a hazard ratio of 3.13.

A 2013 report from the Boston Type 1 Keratoprosthesis Study Group assessed retention of the device in 300 eyes of 300 patients.(8) At a mean duration of follow-up of 17.1 months (range, 1 week to 6 years), 93% of the keratoprostheses were retained. The probability of retention was 94% at 1 year and 89% at 2 years. Mean survival time was 3.8 years. Risk factors for keratoprosthesis loss were autoimmune disease, ocular surface exposure, and number of prior failed penetrating keratoplasties.

An earlier report from the Boston Type 1 Keratoprosthesis Study Group was published in 2006.(9) Thirty-nine surgeons were encouraged to mail standardized pre- and postoperative reports on their patients to a central collection site. Seventeen sites (44%) provided data on 133 patients (136 eyes). The number of patients with BCVA of 20/200 increased from 3.6% to 57%; 19% had postoperative vision of 20/40 or better. Postoperative complications were reported in 109 patients, with 35 occurrences of retroprosthetic membrane and 21 cases of high intraocular pressures.

A limitation of all of these reports is potential bias in the voluntary submission of data.

Retrospective series of the Boston type 1 KPro have been reported from a number of U.S. institutions.

Outcomes. In 2010, Dunlap et al reported a retrospective analysis from 122 patients (126 eyes) at 2 centers who received a Boston type I keratoprosthesis between 2004 and 2007.(10) For most patients, the affected eye had a visual acuity of less than 20/400, and the other eye did not have better vision. Of the 126 eyes, 112 had a history of multiple failed corneal grafts, and 14 received the keratoprosthesis as a primary procedure due to the presence of limbal stem-cell deficiency or the presence of significant ocular surface diseases. Following implantation, 22 eyes (17.4%) did not have improved vision and 8 eyes (6.3%) lost vision, leaving 76% of eyes with improved vision. At 3-month follow-up, 54% of eyes had 20/200 vision or better, with 18% achieving 20/40 or better. In approximately 45% of the eyes, visual acuity remained less than 20/400. The percentage of patients with improved visual outcomes was noted to be lower than in other published studies, due in part to the presence of comorbid conditions, which included glaucoma and retinal detachment.

In 2009, Bradley et al reported outcomes from all of the 30 eyes (28 patients) who had previously received a Boston type 1 keratoprosthesis at their institution; 6 of the eyes had been included in the multicenter study described earlier.(11) Preoperative diagnoses were failed graft (26 eyes, 87%), chemical injury (3 eyes, 10%), and Stevens-Johnson syndrome (1 eye, 3%). Each eye had undergone an average of 2.6 prior corneal transplants (range, 0-7). Twenty eyes (66%) had preoperative glaucoma. Preoperative BCVA ranged from 20/150 to light perception (<20/200 in 83% of eyes). At an average follow-up of 19 months (range, 1-48 months) anatomic retention of the initial keratoprosthesis was 83%, with 5 failures (corneal melting in 4 eyes and infectious keratitis in 1 eye). The number of patients with BCVA of 20/200 or better increased from 14% preoperatively to 77% postoperatively; 23% of patients achieved postoperative vision of 20/40 or better. In the 16 eyes followed up for at least 1 year, 12 (75%) achieved BCVA better than 20/200 and 4 (25%) achieved BCVA better than 20/40. The most common nonsurgical complication was retroprosthetic membrane formation (43% of eyes), followed by increased intraocular pressure (27%), corneal melt (17%), infectious keratitis (17%), endophthalmitis (10%), progression of glaucoma (7%), choroidal effusion or hemorrhage (7%), vitreous hemorrhage (3%), iris prolapse (3%), sterile vitritis (3%), posterior capsular opacity (3%), high myopic refraction (3%), hyphema (3%), and phthisis bulbi (3%). Keratoprosthesis replacement was performed at least once in 5 eyes (17% of patients).

Harissi-Dagher and Dohlman performed a retrospective study of 30 eyes (30 patients) with severe ocular trauma (6 mechanical trauma, 21 chemical burns, and 3 thermal burns) implanted with a Boston KPro type I prosthesis at the Massachusetts Eye and Ear Infirmary since 1990.(12) Patients were followed up for an average of 35 months (range, 1-108 months). Anatomic success (retention of the prosthesis) was achieved in 5 of 5 of the mechanical trauma patients, 14 of 17 of the chemical burn patients, and 3 of 3 of the thermal burn patients. In addition to repeat KPro implantation in 3 patients (2 with early models), repair procedures for leaks were performed in 8 chemical burn eyes. Preoperative visual impairment was near total, with visual acuity ranging from counting fingers to light perception. Postoperatively, 80% of patients achieved BCVA of 20/400 or better, and 53% achieved BCVA of 20/60 or better. There was some attrition in visual acuity over time, primarily from progression of glaucoma in eyes with chemical burns. The authors noted that glaucoma progression is difficult to control in these patients because of damage to the trabecular meshwork and to the retinal ganglion cell layer and nerve fiber layer and that damage to the eye behind the cornea cannot always be diagnosed until the medium (eg, opaque cornea) is cleared. Aquavella et al reported on a case series of 25 patients who received a Dohlman-Doane device.(13) With a follow-up time ranging from 2 to 12 months, 20 of the 25 patients had a visual acuity of 20/400 or better, with 12 patients achieving better than 20/40 vision. There were no dislocations or extrusions, and no reoperations were required within the 2- to 12-month follow-up.

Indications. A 2009 study reported expanding indications and outcomes from a consecutive series of 50 eyes of 49 patients implanted with the Boston type I keratoprosthesis and a donor cornea.(14) In addition to the single patient with bilateral prostheses, 31% of patients had good preoperative vision (visual acuity of 20/40 or better) in the contralateral eye. Patients had to meet the following criteria to be considered a candidate for keratoprosthesis implantation: visually significant corneal opacification (BCVA ≤20/200); poor candidacy for repeat corneal transplantation because of a history of 2 or more failed transplantations, extensive corneal limbal stem-cell failure with or without corneal vascularization and scarring, or both; and adequate visual potential for meaningful visual restoration. Exclusion criteria included: adequate potential for a successful outcome after penetrating keratoplasty; the presence of a comorbid ocular condition associated with a minimal chance of recovering meaningful vision, such as a chronic retinal detachment or near end-stage glaucoma; the presence of comorbid ocular conditions associated with an unacceptably high risk of postoperative complications, such as inadequate eyelid function, severe ocular surface desiccation, ocular surface keratinization, recalcitrant intraocular inflammation, patient inability or unwillingness to comply with the routine postoperative regimen, or a combination thereof. Of the 50 eyes that underwent implantation of the Boston KPro, 42 had a history of prior corneal transplantation, varying between 1 and 5 prior transplantations (mean, 2.3). Preoperative visual acuity was 20/200 or worse in all eyes, with vision of counting fingers, hand movements, or light perception in 42 eyes (88%). Glaucoma was present in 38 eyes (76%) undergoing keratoprosthesis implantation, and tube shunt implantation was performed simultaneously with keratoprosthesis implantation in 45% of the eyes with preexisting glaucoma. A total of 57 Boston type I KPros were implanted in 50 eyes. Two eyes were excluded due to the early death of 1 patient and replacement of the type I KPro with a type II KPro in another patient. Nine of the 57 keratoprostheses implanted were removed, resulting in a retention rate of 84% during an average follow-up of 17 months (range, 3-49 months). Three of the 9 were removed in the first 6 months after surgery, and 5 were removed between 1 and 2 years after surgery. The final postoperative vision was improved over the preoperative vision in 38 eyes (79%), unchanged in 9 eyes (9%), and decreased in 1 eye (2%; from counting fingers preoperatively to light perception postoperatively). The percentage of eyes with postoperative visual acuity of 20/100 or better was 67% of 45 eyes followed up for at least 6 months (90% follow-up), 75% of 28 eyes (56%) followed up to 1 year, 69% of 13 eyes (26%) at 2 years, and all of the 7 eyes (14%) followed up for at least 3 years. In 38 eyes (76%), one or more postoperative complications developed. The most common postoperative complications were retroprosthetic membrane formation (44% of eyes) and persistent epithelial defects (38% of eyes). This detailed report provides information on visual outcomes and complications in a well-described patient population. The major limitation of this study is the small number of subjects who were followed up for more than 6 months.

Use of the Boston KPro has been reported in children and in patients with herpetic keratitis, autoimmune disease, aniridia, atopic keratoconjunctivitis, medication toxicity, and other corneal dystrophies.(15) The device has a lower retention rate when used for highly inflammatory, cicatricial, and autoimmune ocular disorders. Also reported is use of the KPro as a primary treatment in eyes considered to have little or no chance of success with penetrating keratoplasty.(16) The most common preoperative diagnosis was primary or secondary limbal stem-cell disease (71.4%), including chemical/thermal injury (28.6%), aniridia (23.8%), and Stevens-Johnson syndrome (4.8%). Retention rate of the keratoprosthesis was 90.5% at a mean follow-up of 14.6 months (range, 6 to 36.3 months).

Complications. Longer-term vision outcomes and complications with the Boston type 1 KPro was reported by Greiner et al in 2011.(17) Included in the series were all of the 40 eyes of 35 patients who received a Boston KPro between 2004 and 2010 at their institution. Preoperative diagnoses included failed corneal transplants (47.5%), chemical injury (25%), and aniridia (12.5%). Preoperative visual acuity ranged from 20/150 to light perception and was 20/400 or less in 38 eyes (95%). Follow-up evaluations were performed at 1, 3, 6, 9, and 12 months and then annually, with a mean duration of follow-up of 33.6 months (range, 5-72 months). Of 36 eyes followed for at least 1 year, 32 (89%) achieved postoperative BCVA was 20/200 or more. The percentage of eyes that retained BCVA of 20/200 or more was 59% (19/32) at 1 year, 59% (16/27) at 2 years, 50% (7/14) at 3 years, and 29% (2/7) at 4 years or longer. The most common reason for vision loss (54% of the 13 eyes when BCVA ≥20/200 was not retained) was end-stage glaucoma. Other complications included glaucoma drainage device erosion (22.5%), retroprosthetic membrane formation (55%), endophthalmitis (12.5%), and corneal melt (15%). In a separate publication, this group of investigators reported that of 25 eyes implanted with both the Boston type 1 KPro and glaucoma drainage devices, conjunctival breakdown occurred in association with 10 implants in 9 eyes.(18) The authors note that glaucoma continues to be one of the most difficult postoperative management challenges in patients with a Boston type 1 keratoprosthesis.

Posterior segment complications were reported by Goldman et al in 2013.(19) Of 83 eyes (93 procedures) with follow-up of at least 6 months (range, 6 to 84 months), 38 eyes (40.9%) had at least 1 postoperative posterior segment complication, which included retinal detachment (16.9%), choroidal detachment (16.9%), and sterile vitritis (14.5%). Visual acuity was worse in eyes that experienced posterior segment complications compared with eyes that did not. Pujari et al reported outcomes from 29 eyes of 26 patients who received the Boston type II keratoprosthesis between 2000 and 2009 at the Massachusetts Eye and Ear Infirmary.(20) The type II keratoprosthesis is a modification of the original prosthesis, with an anterior extension to allow implantation through surgically closed eyelids and is generally reserved for patients with significant symblepharon or ankyloblepharon, ocular surface keratinization, and absence of normal lid function. Preoperative diagnoses were mucous membrane pemphigoid (51.7%), Stevens-Johnson syndrome/toxic epidermal necrolysis (41.4%), and other ocular surface disease (6.9%). In patients who had more than 1 year of follow-up (mean of 3.7 years), loss of visual acuity was found to occur due to retinal detachment (17.4%), end-stage glaucoma (8.7%), choroidal detachment (8.7%), endophthalmitis (4.3%), and unknown (21.7%). Fourteen eyes (48.3%) required treatment for retroprosthetic membranes. Of the total of 29 eyes, 12 (41.4%) either underwent reimplantation of the device or experienced partial or total extrusion of the keratoprosthesis during follow-up, corresponding to a hazard rate of 0.11 per person-year.

Other Devices

Studies suggest that with the AlphaCor device, thinning or “melting” of the anterior corneal surface can lead to loss of biointegration.(21,22) This complication appears most prevalent in patients with ocular herpes, therefore the AlphaCor device is contraindicated in these patients. In 1 study, the percentage of eyes with visual acuity of better than 20/200 was 42% at an average 30-month follow-up.(21) No additional studies with the AlphaCor were identified in literature updates.

The BIOKOP device is similar in concept to the AlphaCor device in that a microporous polymer is used to promote host tissue integration. However, the results with this device have been disappointing. In 1 case series of 11 patients with 5-year follow-up, the authors concluded that the BIOKOP keratoprosthesis was only able to restore vision for a short postoperative period.(23) Limited success was due to instability of the device and postoperative complications.

Clinical Input Received through Physician Specialty Societies and Academic Medical Centers

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.

In response to requests, input was received from 1 specialty society and 4 academic medical centers while this policy was under review in 2009. Reviewers generally supported a limited role for the Boston KPro in selected patients. Some reviewers recommended use without first attempting a transplant in specific conditions that have a poor prognosis for corneal transplant; however, other input indicated that this is controversial. Some reviewers recommended use only in patients who have limited visual acuity in the contralateral eye. Overall, input indicated that the Boston keratoprosthesis is reserved for cases in which no other alternative (ie, corneal transplantation) is available for treatment of corneal opacification.


Successful development of a keratoprosthesis requires durable clarity, retention, and bioincorporation. The published literature reveals ongoing modifications of the design of the keratoprosthesis, both in terms of the optics and the techniques used for anchoring the optic in place, the surgical technique, and the postoperative management. Randomized trials are unlikely due to very limited indications for this device and a lack of alternative treatments. Patients can serve as their own controls because the comparison of pre- and postoperative visual acuity has some validity given the predictable clinical course and relative lack of confounding factors. As a result, case series with pre- and postcomparisons are the primary type of evidence available; these types of studies are likely to remain small due to the low volume of the procedure.

Some large case series focus on the use of the osteo-odonto keratoprosthesis (OOKP) in Europe. The OOKP device is not widely used in the U.S. Anatomic retention with the OOKP appears good, but restoration of vision is not well-reported.

Based on the literature and clinical input, the Boston KPro is the most widely used and accepted keratoprosthesis in the U.S. at this time. Anatomic retention and visual success of this device at long-term are uncertain, but short-term visual outcomes with the Boston KPro show improvement in a substantial percentage of patients. This remains a high-risk procedure that is associated with numerous complications (such as growth of retroprosthetic membranes) and a probable need for additional surgery. Complications with other designs of keratoprostheses appear to be worse than those associated with the Boston KPro. Therefore, given the available evidence, the clinical input, and the absence of alternative treatment options, the Boston KPro may be considered medically necessary for patients with corneal opacification who have failed corneal transplantation.

Practice Guidelines and Position Statements

The United Kingdom’s National Institute for Clinical Excellence concluded in 2004 that, “Current evidence on the safety and efficacy of insertion of hydrogel keratoprostheses does not appear adequate for this procedure to be used without special arrangements for consent and for audit or research.”(24)

Medicare National Coverage

There is no Medicare national coverage policy. Medicare has established an Ambulatory Payment Classification 0293 for level V anterior segment eye procedures that includes CPT code 65770 (keratoprosthesis) and a HCPCS code for the prosthesis (C1818 - integrated keratoprosthesis OR L8609 - artificial cornea).(25)


  1. Tan A, Tan DT, Tan XW et al. Osteo-odonto keratoprosthesis: systematic review of surgical outcomes and complication rates. Ocul Surf 2012; 10(1):15-25.
  2. Falcinelli G, Falsini B, Taloni M et al. Modified osteo-odonto-keratoprosthesis for treatment of corneal blindness: long-term anatomical and functional outcomes in 181 cases. Arch Ophthalmol 2005; 123(10):1319-29.
  3. Michael R, Charoenrook V, de la Paz MF et al. Long-term functional and anatomical results of osteo- and osteoodonto-keratoprosthesis. Graefes Arch Clin Exp Ophthalmol 2008; 246(8):1133-7.
  4. De La Paz MF, De Toledo JA, Charoenrook V et al. Impact of clinical factors on the long-term functional and anatomic outcomes of osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis. Am J Ophthalmol 2011; 151(5):829-39.
  5. Hughes EH, Mokete B, Ainsworth G et al. Vitreoretinal complications of osteoodontokeratoprosthesis surgery. Retina 2008; 28(8):1138-45.
  6. Liu C, Okera S, Tandon R et al. Visual rehabilitation in end-stage inflammatory ocular surface disease with the osteo-odonto-keratoprosthesis: results from the UK. Br J Ophthalmol 2008; 92(9):1211-7.
  7. Rudnisky CJ, Belin MW, Todani A et al. Risk factors for the development of retroprosthetic membranes with Boston keratoprosthesis type 1: multicenter study results. Ophthalmology 2012; 119(5):951-5.
  8. Ciolino JB, Belin MW, Todani A et al. Retention of the Boston keratoprosthesis type 1: multicenter study results. Ophthalmology 2013; 120(6):1195-200.
  9. Zerbe BL, Belin MW, Ciolino JB. Results from the multicenter Boston Type 1 Keratoprosthesis Study. Ophthalmology 2006; 113(10):1779 e1-7.
  10. Dunlap K, Chak G, Aquavella JV et al. Short-term visual outcomes of Boston type 1 keratoprosthesis implantation. Ophthalmology 2010; 117(4):687-92.
  11. Bradley JC, Hernandez EG, Schwab IR et al. Boston type 1 keratoprosthesis: the university of california davis experience. Cornea 2009; 28(3):321-7.
  12. Harissi-Dagher M, Dohlman CH. The Boston Keratoprosthesis in severe ocular trauma. Can J Ophthalmol 2008; 43(2):165-9.
  13. Aquavella JV, Qian Y, McCormick GJ et al. Keratoprosthesis: the Dohlman-Doane device. Am J Ophthalmol 2005; 140(6):1032-38.
  14. Aldave AJ, Kamal KM, Vo RC et al. The Boston type I keratoprosthesis: improving outcomes and expanding indications. Ophthalmology 2009; 116(4):640-51.
  15. Colby KA, Koo EB. Expanding indications for the Boston keratoprosthesis. Curr Opin Ophthalmol 2011; 22(4):267-73.
  16. Kang JJ, de la Cruz J, Cortina MS. Visual outcomes of Boston keratoprosthesis implantation as the primary penetrating corneal procedure. Cornea 2012; 31(12):1436-40.
  17. Greiner MA, Li JY, Mannis MJ. Longer-term vision outcomes and complications with the Boston type 1 keratoprosthesis at the University of California, Davis. Ophthalmology 2011; 118(8):1543-50.
  18. Li JY, Greiner MA, Brandt JD et al. Long-term complications associated with glaucoma drainage devices and Boston keratoprosthesis. Am J Ophthalmol 2011; 152(2):209-18.
  19. Goldman DR, Hubschman JP, Aldave AJ et al. Postoperative posterior segment complications in eyes treated with the Boston type I keratoprosthesis. Retina 2013; 33(3):532-41.
  20. Pujari S, Siddique SS, Dohlman CH et al. The Boston keratoprosthesis type II: the Massachusetts Eye and Ear Infirmary experience. Cornea 2011; 30(12):1298-303.
  21. Hicks CR, Crawford GJ, Lou X et al. Corneal replacement using a synthetic hydrogel cornea, AlphaCor: device, preliminary outcomes and complications. Eye (Lond) 2003; 17(3):385-92.
  22. Crawford GJ, Hicks CR, Lou X et al. The Chirila Keratoprosthesis: phase I human clinical trial. Ophthalmology 2002; 109(5):883-9.
  23. Alio JL, Mulet ME, Haroun H et al. Five year follow up of biocolonisable microporous fluorocarbon haptic (BIOKOP) keratoprosthesis implantation in patients with high risk of corneal graft failure. Br J Ophthalmol 2004; 88(12):1585-9.
  24. National Institute for Health and Clinical Excellence (NICE). IPG69: Insertion of hydrogel keratoprosthesis. 2004. Available online at: Last accessed January, 2012.
  25. Medicare Program—Revisions to Hospital Outpatient Prospective Payment System and Calendar Year 2007 Payment Rates; Final Rule. Federal Register 2006; 71(226):68052-4.  




CPT  65770  Keratoprosthesis 
ICD-9 Procedure  11.73  Keratoprosthesis 
ICD-9 Diagnosis  369.00-369.08 Blindness and low vision; profound impairment, both eyes - code range
  396.60-396.69 Blindness and low vision; profound impairment, one eye - code range
  371.03 Central opacity of the cornea
  695.13 Stevens-Johnson syndrome
  940.2-940.3 Burn confined to eye; cornea code range
  996.51 Mechanical complication due to corneal graft (rejection of reaction)
  996.69 Infection and inflammatory reaction due to other internal prosthetic device, implant, and graft (includes corneal)
  996.79 Other complications due to other internal prosthetic device, implant or graft (includes corneal)
HCPCS  L8609  Artificial cornea (effective 1/1/06) 
  C1818  Integrated keratoprosthesis 
ICD-10-CM (effective 10/1/15) H17.10-H17.13 Central corneal opacity code range
   H54.0-H54.8 Blindness and low vision code range
   L51.1 Stevens-Johnson Syndrome
   T26.10-T26.12 Burn of cornea and conjunctival sac code range
   T85.79X Infection and inflammatory reaction due to other internal prosthetic devices, implants and grafts (codes from T85 have a 7th digit extender – A for initial, D for subsequent and S for sequela)
   T85.89X Other specified complication of internal prosthetic devices, implants and grafts (codes from T85 have a 7th digit extender – A for initial, D for subsequent and S for sequela)
ICD-10-PCS (effective 10/1/15)    ICD-10-PCS codes are only used for inpatient services.
  08R83JZ, 08R8XJZ, 08R93JZ, 08R9XJZ, 08U80JZ, 08U83JZ, 08U8XJZ, 08U90JZ, 08U93JZ, 08U9XJZ Surgical, eye, replacement, cornea, synthetic substitute, code by body part (right or left), and approach (open, percutaneous or external)
Type of Service  Surgery 
Place of Service  Inpatient 


Dohlman Doane Keratoprosthesis

Policy History

Date Action Reason
3/31/96 Add to Other section; Vision subsection. New policy
12/18/02 Replace policy Policy statement unchanged; expanded description and benefit application
12/17/03 Replace policy Policy reviewed by consensus without literature review; no changes in policy
07/15/04 Replace policy Literature review update; added a new HCPCS code and 2 previously approved FDA devices; no change in policy statement
05/23/05 Replace policy Policy updated with literature review; no change in policy statement. Reference number 7 added
04/25/06 Replace policy Policy updated with literature review; no change in policy statement. Rationale section rewritten; reference numbers 8 and 9 added. HCPCS codes updated in code table
09/18/07 Replace policy Policy updated with literature review; correction of references 10 and 11; references 12 and 13 added; no change in policy statement.
09/10/09 Replace policy Policy updated with literature review through July 2009; 7 references added; policy statement unchanged.
12/03/09 Replace policy Policy updated with literature review; 7 references added; clinical input reviewed. Policy statement changed to may be considered medically necessary when specific criteria are met.
2/10/11 Replace policy Policy updated with literature review through December 2010; reference added; policy statement unchanged
2/09/12 Replace policy Policy updated with literature review through December 2011; references 3 and 12-15 added; some references removed; policy statements unchanged
02/14/13 Replace policy
Policy updated with literature review through January 14, 2013; references 1, 7, and 15 added; policy statement unchanged


2/13/14 Relplace policy Policy updated with literature review through January 14, 2014; references 8 and 19 added; policy statement unchanged


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