Osteo-odonto-keratoprosthesis Research Articles

Mimicking the Physicochemical Properties of the Cornea: A Low-Cost Approximation Using Highly Available Biopolymers.

Corneal diseases represent a significant global health challenge, often resulting in blindness, for which penetrating keratoplasty is the clinical gold standard. However, in cases involving compromised ocular surfaces or graft failure, osteo-odonto keratoprosthesis (OOKP) emerges as a vital yet costly and complex alternative. Thus, there is an urgent need to introduce soft biomaterials that mimic the corneal tissue, considering its translation's physicochemical, biological, and economic costs. This study introduces a cross-linked mixture of economically viable biomaterials, including gelatin, chitosan, and poly-D-lysine, that mimic corneal properties. The physicochemical evaluation of certain mixtures, specifically gelatin, chitosan, and poly-D-lysine cross-linked with 0.10% glutaraldehyde, demonstrates that properties such as swelling, optical transmittance, and thermal degradation are comparable to those of native corneas. Additionally, constructs fabricated with poly-D-lysine exhibit good cytocompatibility with fibroblasts at 72 h. These findings suggest that low-cost biopolymers, particularly those incorporating poly-D-lysine, mimic specific corneal characteristics and have the potential to foster fibroblast survival. While further studies are required to reach a final corneal-mimicking solution, this study contributes to positioning low-cost reagents as possible alternatives to develop biomaterials with physicochemical properties like those of the human cornea.

Osteo-Odonto keratoprosthesis: Tooth for an Eye

Face is the mirror of the mind and the eyes serves as a window to the soul. The sensory system is accountable for providing information to the brain regarding where the body appears in reference to the horizon. Poor vision may lead to loss of balance. Corneal disease is the second most common cause of blindness in the world and occurs in association with a severely damaged corneal and ocular surface. Osteo-Odonto Keratoprosthesis (OOKP) is a surgical procedure to restore vision where the diseased cornea is replaced with an artificial cornea. OOKP consists of autologous tissue derived from tooth and bone that surrounds a central PMMA Optic (Poly Methyl Methacrylate). This review discusses the types, parts, indications, contraindications, surgical techniques and complications of Osteo-Odonto Keratoprosthesis.

Endophthalmitis in Eyes with Osteo-odonto Keratoprosthesis

ABSTRACT Aim: To analyze the incidence, microbiological profile, risk factors, and outcomes in eyes with osteo-odonto keratoprosthesis (OOKP) developing endophthalmitis. Methods & material: Retrospective review of medical records of patients presenting between 2003 and 2013 with OOKP and endophthalmitis was undertaken after obtaining IRB approval. Patient demographics, clinical features, microbiological evaluation, treatment details, and outcomes were analyzed. Results: Of 92 eyes with OOKP, 8 (9%) had endophthalmitis. Indications for OOKP included Steven–Johnson syndrome (SJS; n = 6; 75%) and chemical injuries (n = 2; 25%). The mean duration from OOKP surgery to endophthalmitis was 49.4 ± 32.3 months. Seven of eight eyes had associated laminar resorption. Endophthalmitis resolved with conservative management in three eyes. Lamina removal was required in three eyes; one eye underwent evisceration. At presentation, mean BCVA was 2.76 ± 0.24 logMAR that improved to 2.48 ± 1.0 logMAR after intervention. Mean follow-up was 12.6 ± 13.2 months. Conclusion: Endophthalmitis portends a grave prognosis for eyes with OOKP. The most important risk factors are SJS (75%) and lamina resorption (88%).

Temporo-Parietal Flap Incorporated Into a Modified Osteo-Odonto Keratoprostheses Protocol for Longevity of the Dental Lamina.

To describe a novel pedicled temporo-parietal flap to delay laminar resorption in a modified osteo-odonto keratoprosthesis (MOOKP) and measure resorption of the dental lamina by an objective method. A retrospective case series was performed on patients who received an osteo-odontokeratoprosthesis for Steven-Johnson-Syndrome. Surgeries were performed between October 2016 and November 2017 by the same surgical team (G.M. and S.W.). A modified temporo-parietal flap was incorporated into stage 1 of the MOOKP procedure. CT Scans were performed post op and on follow up. Volumetric evaluation was achieved by automated software analysis of 3D reconstructed CT images (Vitrea, Software Version 6.7.6, Cannon Medical Systems ANZ Pty Ltd). The procedure was performed in 3 eyes from 3 patients. Patients were followed up for stage 2 review at 9.6 months on average (22-55 weeks). One case was complicated by early postoperative hematoma of the buccal graft; however, this was managed conservatively. Another case required relaxing incisions at the time of flap creation due to increased vascularized collagenous tissue. On follow up, volume changes in the dental lamina were minimal. Loss of laminar volume can potentially jeopardize the success of the MOOKP, and consequently cause significant visual, graft or globe complications. The long-term success of this method needs further evaluation; however, initial results suggest a possible role for pedicle grafts in maintenance of the dental lamina. Furthermore, objective CT-based calculation of laminar volume may reduce inter-study variability and standardize comparison of techniques.

Mucosal complications in osteo-odonto keratoprosthesis (OOKP) surgery

Abstract Purpose To study the mucosal complications of osteo-odonto-keratoprosthesis (OOKP) surgery from the UK national keratoprosthesis cohort. Methods A retrospective study was conducted at the Sussex Eye Hospital, Brighton, UK. The case records of patients who underwent OOKP surgery were reviewed and analysed. Results The cohort contained 64 patients, among which 25 were females and 39 were males. Eyelid and adnexal abnormalities were treated in 69% of the cases prior to OOKP surgery. Mucosal graft complications after OOKP affected 46% of the cases after stage 1 and 22% after stage 2. Most of the complications were observed in cases with autoimmune conditions like Stevens-Johnson syndrome (43% post-stage 1, 59% post-stage 2) and cicatrising conjunctivitis (31% post-stage 1, 20% post-stage 2). On the contrary, mucosal overgrowth covering the anterior surface of the optic, which was noted in 28% of the cases, was a common complication after stage 2. Thinning and ulceration of the mucosa was noted in 22% of cases after stage 2. Laminar exposure due to mucosal ulcers was identified in 11 cases. The central part of the mucosa was frequently affected by thinning and ulceration after stage 1. The mucosa overlying the supero-nasal corner of the lamina was eroded commonly after stage 2 leading to exposure of the lamina. Mucosal thinning after stage 1 was treated with conservative measures such as observation and increased lubrication in 15 cases, and with surgical procedures in 7 cases. Post-stage 1 mucosal ulcers were mostly treated by surgery (7 out of 8 cases). Following stage 2, minor cases of mucosal ulcers and thinning and three cases of overgrowth were conservatively treated with lubrication and observation. However, 18 cases of overgrowth required surgical excision. All cases of lamina exposing ulcers were surgically treated. Surgical treatment of mucosal defects included mucosal grafts, flaps and eyelid corrections. Fusion of the eyelids and conversion to a trans-palpebral OOKP were performed in two cases to treat resistant mucosal ulcers. Two eyes lost lamina as a consequence of lamina exposing ulcers. One lamina was explanted due to severe resorption and one due to infection. Conclusion The majority of surgical revisions following OOKP surgery are due to mucosal problems, such as mucosal thinning and ulcerations. These may be treated with increased lubrication of the mucosa or surgical closure of the defects. Mucosal defects resulting in laminar exposure can be a serious threat to laminal viability, and must be treated promptly and aggressively.

Osteo-odonto keratoprosthesis in Egypt: a case series

Purpose The aim of this study was to evaluate the preliminary results of osteo-odonto keratoprosthesis (OOKP) performed in Alexandria Main University Hospital, Alexandria, Egypt in eyes with end-stage cicatrizing conjunctivitis.Patients and methods OOKP surgery was done in two stages. Stage 1 included preparation of the globe, buccal mucous membrane harvesting, and preparation of osteo-odonto alveolar lamina with the cemented optical cylinder. The prepared lamina was then placed in the submuscular space for 2–3 months. In stage 2, the lamina–optical cylinder complex was implanted under the buccal mucous membrane and the posterior part of the optical cylinder was placed in a central corneal opening to act as an artificial cornea, transmitting image to the retina.Results Six eyes with end-stage ocular surface disease were included in this study. Anatomical success, in the form of retention of the prosthesis, was achieved in five eyes. The procedure failed in one eye due to unhealthy canines with a small amount of bone in the lamina. Functional success, defined as restoration of vision, was achieved in four eyes. Visual improvement was not attained in one eye (in addition to the eye with anatomical failure) due to optic atrophy despite good retention of the device.Conclusion OOKP is a promising procedure to regain vision in severe cases of end-stage corneal blindness, unsuitable for cadaveric corneal grafts. Proper selection of cases is crucial to achieve the best anatomical and functional results.

Pearls in the management of Stevens–Johnson syndrome

Stevens–Johnson Syndrome, a life-threatening disorder, can lead to severe ocular morbidity and corneal blindness. The discomfort and visual loss caused leads to a considerable impact on the quality of life. The goals of treatment include measures to reduce inflammation, thereby improving comfort and results for visual rehabilitation. The issues to be addressed include dry eye, lid margin keratinization, adnexal disorders, and fornix obliteration. Measures to address these like punctal cautery and mucous membrane graft have been discussed along with their surgical technique. Visual rehabilitation, following stabilization of the ocular surface, can be achieved with optical iridectomy, cataract surgery or in end-stage disease by performing the modified osteo-odonto keratoprosthesis or Type 2 keratoprosthesis. The procedures to stabilize the ocular surface help in preventing further deterioration of the ocular surface and contribute to improved vision and comfort.

Keratoprostheses in silicone oil-filled eyes: long-term outcomes.

To analyse the functional and anatomical outcomes of different types of keratoprostheses ineyes with retained silicone oil following vitreoretinal surgery. Retrospective chart review of patients operated with any type of permanent keratoprosthesis (Kpro) in silicone oil-filled eyes between March 2003 and June 2017 were analysed. 40 silicone oil-filled eyes underwent keratoprostheses, of which 22 were type 1 and 18 were type 2 Kpros (Lucia variant-nine, modified osteo odonto kerato prosthesis (MOOKP)-four, Boston type 2-three and osteoKpro-two) with a mean follow-up of 61.54 , 42.77, 45.25 , 25 and 37 months, respectively. Anatomic retention of the primary Kpro was noted in 33 eyes (82.5%). A best-corrected visual acuity of better than 20/200 and 20/400 was achieved in 26 (65%)+32 (80%) eyes. Retroprosthetic membrane (RPM) was the most common complication noted in 17 eyes (42.5%). Perioptic graft melt was noted in 4 of 22 eyes of the type 1 Kpro (2 (10.5%) without associated ocular surface disorder (OSD)) and in 1 eye each of Boston and Lucia type 2 Kpro. Laminar resorption occurred in one eye each of the MOOKP and OKP groups. Endophthalmitis and glaucoma did not occur in any eye. Appropriately chosen keratoprosthesis is a viable option for visual rehabilitation in eyes post vitreoretinal surgery with retained silicone oil-induced keratopathy not amenable to conventional penetrating keratoplasty. Kpro melt among type 1 Kpro did not occur in 89.5% eyes without associated OSD (19 of 22 eyes), despite the lack of aqueous humour and presence of RPM (4 eyes), two factors considered to play a significant role in the causation of sterile melts. Of interest to note was the absence of infection in any of these eyes. The possible protective role of oil from endophthalmitis is interesting, though yet to be ascertained.

LVP keratoprosthesis: anatomical and functional outcomes in bilateral end-stage corneal blindness

PurposeTo describe the anatomical and functional outcomes of the novel LVP keratoprosthesis (Kpro), developed as an alternative to the modified osteo-odonto keratoprosthesis (MOOKP), in eyes with end-stage corneal blindness where...

Osteo-odonto keratoprosthesis: Innovative dental and ophthalmic blending.

Corneal diseases are among the major causes of global blindness, secondary to cataract. osteo-odonto keratoprosthesis (OOKP) is the ideal treatment for patients with end-stage inflammatory corneal diseases where a portion of tooth along with bone is used to support an optical cylinder to restore vision in such patients. OOKP surgery requires multidisciplinary approach involving dentists, ophthalmologists, and radiologists. Very less is known in dentistry about the role of the periodontium in the field of ophthalmology. This paper highlights OOKP indications, contraindications, surgical procedure, role of oral structures, advantages, and limitations.

Piezoelectric harvest of osteo-odonto-lamina in modified osteo-odonto keratoprosthesis: A maxillofacial perspective.

Purpose:We describe the piezo-osteotomy feasibility in rehabilitation and harvesting of osteo-odonto lamina in modified osteo-odonto keratoprosthesis (MOOKP) surgery. Surgery was evaluated regarding operative technique and success of the keratoprosthesis (KPros) in terms of perception to light (+ve) to finger counting (+ve).Materials and Methods:This retrospective cohort study included 12 patients undergone MOOKP surgery procedures. Harvesting of osteo-odonto-lamina was performed using piezosurgical osteotomy during 2007–2012.Results:The mean follow up was 34 months (range 24–48 months). Of the 12 patients six patients had vision ≥6/12, four patients had vision <6/12, but >6/60 and one patients had vision ≤6/60. KPros was retained and functional in all the eyes after a minimum follow up of 24 months. There was mucosal overgrowth over the optical cylinder occurred in two cases over 4 years follow up which was corrected with trimming. Postoperative complication at donor site was seen in three cases, two cases with exposure of root of adjacent teeth and oro antral fistula in one.Conclusions:This study suggests that piezoelectric harvest of osteo-odonto-lamina is a valuable surgical option in patients undergoing MOOKP surgery, resulting in high success rate with less complication.

20 Years of Advances in Keratoprosthesis

Keratoprosthesis (KPro) has revolutionized the treatment of patients with severe corneal diseases who do not benefit from allogeneic corneal transplantation. Since the introduction of KPro over 200 years ago, numerous designs and techniques have been suggested. Of these, the Boston keratoprosthesis and osteo-odonto keratoprosthesis (OOKP) are the two most commonly used keratoprostheses worldwide. Over the past few decades, various improvements in designs, surgical techniques, and postoperative care have expanded the indications for the Boston KPro. With better control of devastating ocular complications, such as endophthalmitis and extrusion, glaucoma has become the most common long-term complication leading to blindness. OOKP involves a more complex surgical procedure compared to the Boston KPro, but has gained traction due to its effectiveness in treating very severe ocular surface diseases. The current trend of Boston KPro studies focuses on better intraocular assessment tools to diagnose and manage glaucoma, as well as alternative biomaterials to improve biocompatibility and retention rates. Recent improvements in OOKP mainly focus on augmentation techniques of the biological skirt to prevent or decrease both keratolysis and laminar resorption.

Biomaterials: Impact on Keratoprosthesis Implantation

Purpose of Review The increasing demand for corneal tissue and clinical circumstances of severe corneal scarring and vascularization have stimulated a continued interest in developing an artificial cornea from innovative biomaterials. We review the latest findings on the variety of materials used for artificial corneas and keratoprostheses, focusing most heavily on the Boston keratoprosthesis, the AlphaCor, and the Osteo-odonto Keratoprosthesis.

Bone augmentation of the osteo-odonto alveolar lamina in MOOKP--will it delay laminar resorption?

We aimed to describe a new technique and analyse the early outcomes of augmenting the canine tooth using a mandibular bone graft in an attempt to delay or retard the process of laminar resorption following the modified osteo odonto keratoprosthesis (MOOKP) procedure. This was a retrospective case series. Eyes that underwent the bone augmentation procedure between December 2012 and February 2014 were retrospectively analysed. The procedure, performed by the oromaxillofacial surgeon, involved securing a mandibular bone graft beneath the periosteum on the labial aspect of the canine tooth chosen to be harvested for the MOOKP procedure. This procedure was performed simultaneously with the Stage 1 A of the MOOKP. Three months later, the tooth was harvested and fashioned into the osteo-odonto alveolar lamina similar to the method described in the Rome-Vienna Protocol. The bone augmentation procedure was performed in 11 eyes (five SJS/ six chemical injuries). The mean follow-up after Stage 2 of MOOKP procedure in these eyes was 7.45 months (2 to 20 months). Complications noted were peripheral laminar exposure (three eyes-SJS) and bone graft exposure and necrosis in the mouth (nine-SJS). No evidence of clinical laminar resorption was noted in any of the eyes. Laminar resorption in MOOKP can lead to vision and globe threatening complications due to the consequent cylinder instability and chances of extrusion. Augmenting the bone on the labial aspect of the canine tooth might have a role to play in delaying or preventing laminar resorption.

Periodontium bestows vision!!

The role of periodontium in supporting the tooth structures is well-known. However, less is known about its contribution to the field of ophthalmology. Corneal diseases are among major causes of blindness affecting millions of people worldwide, for which synthetic keratoprosthesis was considered the last resort to restore vision. Yet, these synthetic keratoprosthesis suffered from serious limitations, especially the foreign body reactions invoked by them resulting in extrusion of the whole prosthesis from the eye. To overcome these shortcomings, an autologous osteo-odonto keratoprosthesis utilizing intraoral entities was introduced that could positively restore vision even in cases of severely damaged eyes. The successful functioning of this prosthesis, however, predominantly depended on the presence of a healthy periodontium for grafting. Therefore, the following short communication aims to acknowledge this lesser-known role of the periodontium and other oral structures in bestowing vision to the blind patients.

Structural &amp; functional rehabilitation in eyes with lamina resorption following MOOKP—can the lamina be salvaged?

To describe a new technique and analyze the outcome of procedures performed for anatomic and functional rehabilitation in eyes with lamina resorption following the modified osteo-odonto keratoprosthesis (MOOKP) procedure. Retrospective case series. Eighteen eyes were noted to have lamina resorption of the 85 eyes that underwent the MOOKP surgery over the last 10 years. Further intervention to salvage the globe, and therefore the visual potential, was possible in only 11 eyes, of which two are yet to undergo further intervention. Two patients who had undergone the procedure elsewhere also presented to our centre with evidence of resorption. In all, 11 eyes (nine operated at our centre, two operated elsewhere) were included in this study. Bone morphogenetic protein (BMP) was used alone or along with mandibular cancellous bone within the fibrovascular capsule of the osteo-odonto alveolar lamina, in an effort to prevent further resorption and promote bone generation in areas of resorption in ten eyes. In three of these eyes, there was a continued progression of resorption requiring lamina removal. In these three eyes and another eye with extrusion of the cylinder from the eye, the Lucia Type 2 keratoprosthesis was performed for visual rehabilitation (four eyes). The BMP procedure was performed in ten eyes. Continued resorption with need for further rehabilitative surgery in the form of Lucia Type 2 Kpro was required in three of these eyes. Of the four patients who had the Lucia Type 2 Kpro, visual acuity improved to better than 20/200 in three eyes over a mean follow-up period of 3 months. Of the remaining seven eyes that had the BMP procedure performed, all have remained stable with respect to anatomic integrity of the lamina and globe, with maintenance of or improvement in pre BMP visual acuity over a mean follow-up of 9.2 months. No other complications of the procedure were noted. Resorption of the lamina in MOOKP can be addressed by reinforcing the same with BMP in eyes where the cylinder mobility is not significant, as a means to prolong the longevity of the existing lamina. The Lucia Type 2 Kpro might also have a role to play in the functional rehabilitation of eyes with severe lamina resorption or cylinder extrusion if preparation of a new lamina cannot be performed for various reasons.

Cost-Effectiveness of Osteo-Odonto Keratoprosthesis in Singapore

To determine the long-term cost-effectiveness of osteo-odonto keratoprosthesis (OOKP) relative to no treatment among patients with end-stage corneal and ocular surface diseases in Singapore. Cost-effectiveness analysis based on data from a retrospective cohort study. From a health system perspective, we calculated the incremental cost-effectiveness ratio of OOKP treatment relative to no treatment over a 30-year horizon, based on data from a cohort of 23 patients who underwent OOKP surgery between 2004 and 2009 at Singapore National Eye Centre. Preoperative and postoperative vision-related quality-of-life values were estimated from patients' visual outcomes and were used to calculate the gain in quality-adjusted life years (QALYs) resulting from OOKP treatment. Unsubsidized costs for surgery, consultations, examinations, medications, follow-up visits, and treatments for complications were retrieved from patients' bills to estimate the total costs associated with OOKP treatment. Sensitivity analyses were conducted to test the robustness of the model. Over a 30-year period, OOKP treatment, compared with no treatment, improved QALYs by 3.991 among patients with end-stage corneal and ocular surface diseases at an additional cost of S$67 840 (US$55 150), resulting in an incremental cost-effectiveness ratio of S$17 000/QALY (US$13 820/QALY). Based on commonly cited cost-effectiveness benchmarks, the OOKP is a cost-effective treatment for patients with end-stage corneal and ocular surface diseases.

Mucosal Complications of Modified Osteo-odonto Keratoprosthesis in Chronic Stevens-Johnson Syndrome

To describe clinical outcomes of complications afflicting the autologous oral mucous membrane graft after modified osteo-odonto keratoprosthesis surgery in chronic Stevens-Johnson syndrome (SJS). Prospective case series. This study included 30 eyes of 30 patients with SJS-induced dry keratinized ocular surfaces; the patients underwent various stages of this procedure between August 2009 and February 2012. Mucosal complications were classified as either necrosis or overgrowth. Mucosal necrosis was managed according to a predesigned algorithm based on timing (pre- and postimplantation) and location (central or peripheral) of necrosis. Cases with mucosal overgrowth underwent mucosal debulking and trimming. Mucosal necrosis developed in 15 (50%) eyes and overgrowth in 4 (13.3%) eyes. Preimplantation necrosis (n = 7) was initially managed conservatively, but 2 eyes required free labial-mucous membrane grafting for persistent corneal exposure. Free labial-mucous membrane grafting was performed in all cases of postimplantation necrosis (n = 10), but 8 eyes required additional tarsal pedicle flaps (n = 6, for peripheral necrosis) or through-the-lid revisions (n = 2, for central necrosis). Debulking and trimming effectively managed all cases of mucosal overgrowth, but 3 eyes required repeat procedures. At 24.1 ± 6.5 months postimplantation, the keratoprosthesis was retained in all eyes, and the probability of maintaining 20/60 or better vision was similar in eyes with or without mucosal necrosis (86 ± 8.8% vs 80 ± 10.3%). Mucosal complications, especially necrosis, occurred commonly following modified osteo-odonto keratoprosthesis surgery in dry keratinized post-SJS eyes. The algorithm-based management approach described in this study was successful in treating these complications, retaining the prosthesis and preserving useful vision.

Biointegration of the Osteo-odonto Lamina in the Modified Osteo-odonto Keratoprosthesis: Engineering of Tissue to Restore Lost Vision

The modified osteo-odonto keratoprosthesis (MOOKP) is a biologic keratoprosthesis that is used to treat a severely scarred cornea. The procedure involves multiple stages, including the transplantation of buccal mucosa to the damaged ocular surface and the implantation of an osteo-odonto lamina with a mounted polymethylmethacrylate lens. Among the keratoprostheses currently available, the MOOKP has proven to be the most effective based on the number of patients who have undergone the procedure and the duration of documented follow-up. Upon successful biointegration of the osteo-odonto lamina, the keratoprosthesis is able to resist resorption, provide stability, and prevent bacterial invasion and epithelial ingrowth. The effectiveness of the MOOKP is dependent on the anatomic and physiologic characteristics of the dental tissues and periodontal ligament.

An update on imaging and strengthening of the OOKP lamina

AbstractAbstract not provided