INTRODUCTION:The osteo-odonto-keratoprosthesis (OOKP) is the most durable device among all keratoprostheses (KPros) to date. The aim of this study was to present a brief overview of the long-term outcomes and key lessons learned from this cohort. METHODS:A retrospective review of OOKP patient records who completed at least one year of follow-up was conducted. Visual outcomes, complications, and laminar survival were analyzed. Kaplan-Meier survival curves with the log-rank test were used to assess for statistically significant differences between groups. RESULTS:A total of 64 patients were included in this study; 65 eyes had complete OOKP procedures. In total, 60 tooth autografts, 11 tooth allografts, and 3 tibial grafts were implanted in this cohort. Stevens-Johnson syndrome (SJS) was the most common indication for OOKP (43%, n = 27), while glaucoma was the most frequent complication (86%, n = 57). The probability of retaining a functioning OOKP lamina for autografts was 91% over 18 years ( P = 0.001) and over 15 years. After 10 years of follow-up, 59% ( n = 13/22) of eyes with surviving laminae had a visual acuity (VA) of 6/12 or better, and 82% ( n = 18/22) had vision better than 6/60. Eyes with autografts showed a 34% probability of retention of 6/12 or better VA and a 71% probability of retaining VA between 6/12 and 6/60 ( P = 0.332). CONCLUSION:SJS was the most common diagnosis. Endophthalmitis was the common cause of visual loss, and glaucoma was the common cause of lack of visual improvement after OOKP. Overall, OOKP offers excellent long-term anatomical retention of the lamina and visual restoration.

In most countries, the supply of corneal material do not meet the demands for corneal transplantation. This has been exacerbated by COVID‐19. Patients have not been seen during lockdown. Many are presenting late. There has been fewer operations done during the pandemic resulting in a backlog. Even in normal times, there are cases of corneal blindness not amenable to cadaveric corneal transplantation. The clinical and research community have two tasks. One is to develop artificial corneae or contructs through biotechnology to replace cadaveric transplantation. The other is to improve keratoprostheses which are used for vascularised corneae and multiple previous failed grafts (Boston KPro1 and similar) and for dry keratinised ocular surface (the OOKP and alternatives).

This is an Editorial and does not have an abstract. Please download the PDF or view the article in HTML.

Corneal transplant aims to replace opacified, scarred or deformed cornea with cadaveric donor material. However, there are two clinical scenarios when we need to consider bypassing the ocular surface and cornea with a keratoprosthesis to restore sight in corneal blindness. Where there have been multiple graft failures or a heavily vascularised cornea, and in the presence of adequate tear production and perfect blinking mechanism, a Boston Type 1 keratoprosthesis (BKPro1) may be considered instead of high-risk conventional keratoplasty. BKPro1 is a Polymethylmethacrylate (PMMA) and titanium collar stud device that sandwiches a carrier corneal graft button for full-thickness transplantation. Limbal stem cell deficiency is not a problem, but any degree of keratinisation, tarsal or bulbar, will compromise the outcomes. Were the ocular surface is hostile with keratinisation, and in the presence of a defective lid or blink, an osteo-odonto-keratoprosthesis (OOKP) is indicated. The OOKP is an epicorneal device using a lamina created from the patient’s own canine tooth root and surrounding jawbone to carry a PMMA optical cylinder wrapped with an overlying buccal mucous membrane graft. Keratoprostheses are inherently unstable and should not be used when there is a fellow-seeing eye and should not be implanted bilaterally. Although they may be visually devastating, the rate of complications of keratoprostheses has been significantly reduced by improving the design of the devices and the development of prevention and management protocols for the complications.

Purpose: Background: The osteo-odonto-keratoprosthesis (OOKP) is the device of choice for restoring sight in end-stage corneal blindness not amenable to conventional corneal transplantation. A bio-integrable lamina created from an autologous single-rooted tooth is used to frame a PMMA optical cylinder. The lamina is sealed by an overlying buccal mucous membrane graft. An OOKP has a survival rate of 80% over 18 years. The lamina is subject to resorption over time. Clinical and radiological observation are essential for detecting impending laminar failure. Aims: Case report and literature review to illustrate the limits of clinical and radiological observation of an OOKP. Methods: Retrospective case study of a 40-year-old male with bilateral corneal blindness from Stevens Johnson Syndrome, first presenting in 1996 with light perception vision, underwent left Stage 1 (March 1997) and Stage 2 OOKP (June 1997) surgery. Post-operatively, his visual acuity was 6/5+ (1.2, 20/15). Results: Regular CT imaging revealed no loss of volume or impending failure. He presented with severe eye pain on 11.12.2016, having had a normal quarterly review 5 days beforehand. He underwent endoscopic vitrectomy, biopsy and intravitreal antibiotics on 12.12.2016 for endophthalmitis (Group B Streptococcus). Despite efforts to treat his infection, his left eye was eviscerated on 16.12.2016. Later study of the lamina revealed a hairline crack not visible on CT imaging. Conclusions: We discuss an unforeseen case of a failed OOKP lamina due to a hairline crack despite limited laminar resorption. Current management options for failing laminae include insertion of a new lamina, bone morphogenetic protein ± bone graft, an alternative device, and removal of device and closure of the corneal opening with a small full thickness corneal graft. Hairline cracks remain an Achilles' heel. There should be a high index of suspicion of endophthalmitis even in the presence of good laminar bulk.

Keratoprostheses are last resort procedures and are inherently unstable. A multidisciplinary team needs to be in place, available 24/7/365 through a coordinator, with the team led by the main keratoprosthesis surgeon. There should be a telephone number and email address which are manned day and night year round. Attention should be paid to colocation of subspecialty team members who will have different timetables. Vitreoretinal expertise, including endoscopic vitrectomy expertise, and operating theatre time should be instantly available for infection and macular on retinal detachments. The extended team may include eye surgeons (corneal, adnexal, glaucoma, vitreoretinal), maxilla-facial surgeons, anaesthetists, radiologists, fellows, and a coordinator supported by named nurses in theatres, ward and outpatients. Attention should be paid to make keratoprosthesis services more robust by having more than one key person for key roles to cover leave and sickness and orderly succession planning.

Ophthalmic surgical operating lists include intraocular and extraocular procedures, as well as clean non-infectious and dirty infectious cases. Patient age, diabetic status, local or general anaesthesia must be considered during ophthalmic theatre scheduling. Traditionally children and 'clean cases' are prioritised. However, factors such as the need for an interpreter, patient transport and latex allergy affect the sequencing of ophthalmic lists. An electronic survey was sent to all UK ophthalmology consultants through the Royal College of Ophthalmologists registry, enquiring about their preference in sequencing mixed theatre lists, what operations they considered clean and dirty, and the presence of departmental protocol for list sequencing. There was a 16.9% response rate (n=222/1311). A majority of 75.2% (n=167/222) had mixed operating lists of intraocular and extraocular cases. Of those performing mixed operating lists, 44.3% (n=74/167) stated they would operate on intraocular cases before extraocular cases, and 92.8% (n=155/167) would perform 'clean' before 'dirty' cases. Fifty-nine per cent (n=98/167) have a departmental protocol to help determine list order. This survey has demonstrated that there is a trend to perform 'clean' before 'dirty' and intraocular before extraocular cases. Given the results of the survey, we outline our recommendation on how to sequence mixed ophthalmic theatre lists.

Purpose: We present a no-touch Descemet membrane endothelial keratoplasty (DMEK) technique which assists in unfolding of tightly scrolled grafts from young donors. Methods: The technique was developed following a wet-laboratory experiment using human corneas created to observe the behavior of the graft during spinning within the artificial anterior chamber. This approach involves injecting short bursts of balanced salt solution to make the scroll spin continuously in a 360-degree manner. Spinning of the graft over the surface is accompanied by rotation on its horizontal axis resulting in opening in the correct orientation. Unfolding is then completed with standard bimanual tapping maneuvers. The spinning technique was then performed in 4 patients who all had tight DMEK scrolls from young donors. Results: The wet laboratory confirmed that directed jets of fluid to generate spinning and rotation open the graft in the correct orientation in most occasions. All 4 cases in this study received grafts from young donors (range 37-48 years old), and the technique achieved rapid unfolding with no complications. Two of our patients had glaucoma drainage devices, 1 had anterior chamber intraocular lens, and all other cases had clear corneas and good endothelial cell count after the 1-year follow-up. Conclusions: Our novel technique provides a safe and effective method to unscroll tight DMEK grafts that surgeons could incorporate into their armamentarium. Success is optimized by slightly undersizing the graft (7.5-8.0 mm).

Superficial keratectomy (SK) is the manual dissection of the superficial corneal layers (epithelium, Bowman's layer, and sometimes superficial stroma). SK is done using a surgical blade or diamond burr. Some surgeons use intraoperative mitomycin C 0.02% or amniotic membrane transplantation to improve surgical outcomes. This literature review shows that SK remains an effective method for different indications, including tissue diagnosis, excision of corneal degenerations, dystrophies, scarring, recurrent corneal erosions, and retained corneal foreign body.

Background Surgery for established cataract is highly cost-effective and uncontroversial, yet uncertainty remains for individuals about when to proceed and when to delay surgery during the earlier stages of cataract. Objective We aimed to improve decision-making for cataract surgery through the development of evidence-based clinical tools that provide general information and personalised risk/benefit information. Design We used a mixed methodology consisting of four work packages. Work package 1 involved the development and psychometric validation of a brief, patient self-reported measure of visual difficulty from cataract and its relief from surgery, named Cataract Patient-Reported Outcome Measure, five items (Cat-PROM5). Work package 2 involved the review and refinement of risk models for adverse surgical events (posterior capsule rupture and visual acuity loss related to cataract surgery). Work package 3 involved the development of prediction models for the Cat-PROM5-based self-reported outcomes from a cohort study of 1500 patients; assessment of the validity of preference-based health economic indices for cataract surgery and the calibration of these to Cat-PROM5; assessment of patients’ and health-care professionals’ views on risk–benefit presentation formats, the perceived usefulness of Cat-PROM5, the value of personalised risk–benefit information, high-value information items and shared decision-making; development of cataract decision aid frequently asked questions, incorporation of personalised estimates of risks and benefits; and development of a cataract decision quality measure to assess the quality of decision-making. Work package 4 involved a mixed-methods feasibility study for a fully powered randomised controlled trial of the use of the cataract decision aid and a qualitative study of discordant or mismatching perceptions of outcome between patients and health-care professionals. Setting Four English NHS recruitment centres were involved: Bristol (lead centre), Brighton, Gloucestershire and Torbay. Multicentre NHS cataract surgery data were obtained from the National Ophthalmology Database. Participants Work package 1 – participants ( n = 822) were from all four centres. Work package 2 – electronic medical record data were taken from the National Ophthalmology Database (final set > 1M operations). Work package 3 – cohort study participants were from Bristol ( n = 1200) and Gloucestershire ( n = 300); qualitative and development work was undertaken with patients and health-care professionals from all four centres. Work package 4 – Bristol, Brighton and Torbay participated in the recruitment of patients ( n = 42) for the feasibility trial and recruitment of health-care professionals for the qualitative elements. Interventions For the feasibility trial, the intervention was the use of the cataract decision aid, incorporating frequently asked questions and personalised estimations of both adverse outcomes and self-reported benefit. Main outcome measures There was a range of quantitative and qualitative outcome measures: questionnaire psychometric performance metrics, risk indicators of adverse surgical events and visual outcome, predictors of self-reported outcome following cataract surgery, patient and health-care practitioner views, health economic calibration measures and randomised controlled trial feasibility measures. Data sources The data sources were patient self-reported questionnaire responses, study clinical data collection forms, recorded interviews with patients and health-care professionals, and anonymised National Ophthalmology Database data. Results Work package 1 – Cat-PROM5 was developed and validated with excellent to good psychometric properties (Rasch reliability 0.9, intraclass correlation repeatability 0.9, unidimensionality with residual eigenvalues ≤ 1.5) and excellent responsiveness to surgical intervention (Cohen delta –1.45). Work package 2 – earlier risk models for posterior capsule rupture and visual acuity loss were broadly affirmed ( C -statistic for posterior capsule rupture 0.64; visual acuity loss 0.71). Work package 3 – the Cat-PROM5-based self-reported outcome regression models were derived based on 1181 participants with complete data ( R 2 ≈ 30% for each). Of the four preference-based health economic indices assessed, two demonstrated reasonable performance. Cat-PROM5 was successfully calibrated to health economic indices; adjusted limited dependent variable mixture models offered good to excellent fit (root-mean-square error 0.10–0.16). The personalised quantitative risk information was generally perceived as beneficial. A cataract decision aid and cataract decision quality measure were successfully developed based on the views of patients and health-care professionals. Work package 4 – data completeness was good for the feasibility study primary and secondary variables both before and after intervention/surgery (data completeness range 100–88%). Considering ability to recruit, the sample size required, instrumentation and availability of necessary health economic data, a fully powered randomised controlled trial (patients, n = 800, effect size 0.2 standard deviations, power 80%; p = 0.05) of the cataract decision aid would be feasible following psychometric refinement of the primary outcome (the cataract decision quality measure). The cataract decision aid was generally well-received by patients and health-care professionals, with cautions raised regarding perceived time and workload barriers. Discordant outcomes mostly related to patient dissatisfaction, with no clinical problem found. Limitations The National Ophthalmology Database data are expected to include some errors (mitigated by large multicentre data aggregations). The feasibility randomised controlled trial primary outcome (the cataract decision quality measure) displayed psychometric imperfections requiring refinement. The clinical occurrence of discordant outcomes is uncommon and the study team experienced difficulty identifying patients in this situation. Future work Future work could include regular review of the risk models for adverse outcomes to ensure currency, and the technical precision of complex-numbers analysis of refractive outcome to invite opportunities to improve post-operative spectacle-free vision. In addition, a fully powered randomised controlled trial of the cataract decision aid would be feasible, following psychometric refinement of the primary outcome (the cataract decision quality measure); this would clarify its potential role in routine service delivery. Conclusions In this research programme, evidence-based clinical tools have been successfully developed to improve pre-operative decision-making in cataract surgery. These include a psychometrically robust, patient-reported outcome measure (Cat-PROM5); prediction models for patient self-reported outcomes using Cat-PROM5; prediction models for clinically adverse surgical events and adverse visual acuity outcomes; and a cataract decision aid with relevant general information and personalised risk/benefit predictions. In addition, the successful mapping of Cat-PROM5 to existing health economic indices was achieved and the performances of indices were assessed in patients undergoing cataract surgery. A future full-powered randomised controlled trial of the cataract decision aid would be feasible (patients, n = 800, effect size 0.2 standard deviations, power 80%; p = 0.05). Trial registration This trial is registered as ISRCTN11309852. Funding This project was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research ; Vol. 10, No. 9. See the NIHR Journals Library website for further project information.

Purpose: Patient education and understanding has been shown to improve outcomes by enabling engagement. Information relating to ophthalmic disease and surgery is often complex, pertaining to microanatomy of the eye and adnexa. The use of three-dimensional anatomical models in clinical consultations is one method that can improve patients' understanding of their ophthalmic condition(s) and procedure(s). Our research group surveyed the current app marketspace for virtual smartphone anatomical models that can be readily deployed in any ophthalmic clinic setting for the benefit of patients and clinicians alike. Methods: We conducted a systematic review of Google's ‘Play Store’ and Apple's ‘App Store’ – the two most commonly used app stores – using the key term ‘eye anatomy’. Apps were excluded if they were not related to ophthalmology and if they did not offer a 3D function that could rotate 360°. All relevant apps were evaluated by three parameters: 3D Features, Highlights individual anatomical features, and Cost. Results: The ‘Play Store’ generated 250 results of which 20 were relevant. The ‘App Store’ generated 211 results of which 12 were relevant. Between the ‘Play Store’ and ‘App Store’ there was an overlap of 7 apps. These apps offered a variety of 3D features including 360° rotation, X-ray and animation modes, and virtual/augmented/mixed reality options. Of the relevant 25 Google and Apple apps, 76% (19/25) offered a function to highlight individual anatomical features. 32% (8/25) of these apps were free and the remaining 68% (17/25) had a price range from £0.89 to £36.62, averaging at £10.36 per app. Conclusions: The availability of medical smartphone applications has proliferated over the past two decades. Whilst there is a wealth of applications available to aid ophthalmology anatomy learning, further improvements and content regulation from specialists is required to maintain a high standard of content. This study is the first to systematically evaluate smartphone apps within the context of ophthalmic anatomy.

Purpose: To analyze and review the clinical features and main outcomes of laminar resorption from the UK osteoodonto-keratoprosthesis (OOKP) cohort. Methods: A retrospective review of case records was undertaken for patients who underwent keratoprostheses between 1996 and 2014 at the Sussex Eye Hospital, Brighton, UK. The main clinical outcomes of resorption, including its clinical signs, complications, treatments, and laminar survival, were evaluated. Results: Sixty-four patients (25-females, 39-males) were included, and in total, 74 laminae (3-tibial, 11-allografts, 60-autografts) were implanted. The age of the patients ranged from 20 to 91 years. Focal laminar thinning was the first sign of detectable resorption in 50% of autografts and 27% of allografts. All the tibial grafts and 55% of allografts presented with complications of resorption like endophthalmitis and aqueous leakage as the first signs of resorption. The survival of first implanted autografts was 82.4%(+/- 6.3%) at 18 years, which was enhanced to 91.5%(+/- 5.0%) by prophylactic exchanges of critically resorbed laminae with new laminae. Visual acuity survival analysis did not reveal a statistically significant difference between grafts with and without resorption for all graft types (p = 0.825). Patients treated with Alendronic acid and acetazolamide demonstrated trends toward the slower progression of resorption, but this was not statistically significant. Conclusions: Focal laminar thinning was the common presenting feature of resorption in autografts. Timely replacement of the resorbed laminae with new laminae should be considered to avoid complications. Alendronic acid supplementation may be considered in high-risk cases of resorption to reduce further progression.

Purpose The purported benefits and risks of immediately sequential bilateral cataract surgery (ISBCS) have been well described, yet the procedure remains controversial among UK ophthalmologists. As many of the controversies of ISBCS are underpinned by ethical dilemmas, the aim of this work was to explore the ethical perspectives of ISBCS from a variety of stakeholder viewpoints. Method A semi-structured independent stakeholder meeting was convened at the Royal College of Ophthalmologists London headquarters in June 2018. In total, 29 stakeholders attended the meeting. The professional characteristics of stakeholders included but were not limited to: ophthalmologists (9), patients (5), religious leaders (4), ethicists (2), lawyers (2) and commissioners (1). Thematic qualitative analysis using methodology proposed by Braun and Clarke was conducted on the resultant transcript of the discussion. Results Themes identified include: (1) beneficence and non-maleficence (patient benefits, patient risks, the uncertainties of risk, patient interpretation of the risk-benefit analysis); (2) autonomy (informed consent, the barriers to communication); (3) distributive justice (the allocation of resources: the individual vs the collective). Conclusion This analysis provides a reference point for the ethical factors surrounding ISBCS. The stakeholders concluded that this approach was an ethical undertaking provided patient autonomy was appropriately attained. This requires a patient’s interpretation of the risk-benefit balance, which must include an understanding of the low but unquantifiable risk of severe complications. A surgeon must aim to minimise risks through the adaption of accepted surgical protocols and by performing appropriate patient selection. Currently, cost savings to healthcare that may occur following the implementation of ISBCS should be considered a secondary benefit of the protocol.

Osteo-odonto-keratoprostheses, incorporating dental laminate material as an anchoring skirt around a central poly(methyl methacrylate) (PMMA) optic, have been used to replace the cornea for many years. However, there are many intricacies associated with the use of autologous dental laminate material, surgical complexity and skirt erosion. Tissue engineering approaches to bone replacement may offer suitable alternatives in osteo-odonto-keratoprosthesis (OOKP) surgery. In this study, a hydrogel polymer composite was investigated as a synthetic substitute for the OOKP skirt. A novel high strength interpenetrating network (IPN) hydrogel composite with nano-crystalline hydroxyapatite (nHAp) coated poly (lactic-co-glycolic acid) PLGA microspheres was created to mimic the alveo-dental lamina by employing agarose and poly(ethylene glycol) diacrylate (PEGDA) polymers. The incorporation of nHAp coated PLGA microspheres into the hybrid IPN network provide a micro-environment similar to that of skeletal tissues and improve cellular response. Agarose was used as a first network to encapsulate keratocytes/3T3 fibroblasts and PEGDA (6000 Da) was used as a second network with varying concentrations (20 and 40 wt %) to produce a strong and biocompatible scaffold. An increased concentration of either agarose or PEG-DA and incorporation of nHAp coated PLGA microspheres led to an increase in the elastic modulus. The IPN hydrogel combinations supported the adhesion and proliferation of both fibroblast and ocular human keratocyte cell types during in in-vitro testing. The cells endured the encapsulation process into the IPN and remained viable at 1 week post-encapsulation in the presence of nHAp coated microspheres. The material did not induce significant production of inflammatory cytokine IL-6 in comparison to a positive control ( p < 0.05) indicating non-inflammatory potential. The nHAp encapsulated composite IPN hydrogels are mechanically strong, cell supportive, non-inflammatory materials supporting their development as OOKP skirt substitutes using a new approach to dental laminate biomimicry in the OOKP skirt material.

From the Sussex Eye Hospital, Brighton, United Kingdom, Brighton and Sussex Medical School, Brighton, United Kingdom, Tongdean Eye Clinic, Hove, United Kingdom. Corresponding author: Christopher Liu, OBE, FRCOphth, FRCSEd, FRCP, Sussex Eye Hospital, Eastern Rd, Brighton BN2 5BF, United Kingdom. Email: [email protected]. First author:Christopher Liu, OBE, FRCOphth, FRCSEd, FRCPSussex Eye Hospital, Brighton, United Kingdom