KPro Implantation Research Articles

Vision-Related Quality of Life After Fyodorov-Zuev Keratoprosthesis in China.

The purpose of this study was to assess vision-related quality of life (VR-QoL) and its determinants in patients with implanted Fyodorov-Zuev (MICOF) KPro. Eighty-eight patients with bilateral corneal blindness who underwent unilateral Fyodorov-Zuev (MICOF) KPro implantation were included in this cross-sectional study. VR-QoL was assessed using the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25). Univariate analyses and multivariate linear regression were used to identify VR-QoL determinants. Eighty-eight patients, aged 50.00 ± 13.72 years, with a mean postoperative time of 5.13 ± 3.31 years, were included. The composite NEI-VFQ-25 score improved from 17.04 ± 5.60 to 46.00 ± 19.21 (P < 0.01) after Fyodorov-Zuev (MICOF) KPro implantation. The multivariate linear regression analysis results showed that the postoperative composite score was correlated with postoperative visual acuity (VA) of the operative eye (B = -21.66, P < 0.01). Improvement in NEI-VFQ scores was associated with better postoperative VA of the operative eye (B = -18.67, P < 0.01) and poorer preoperative VA of the fellow eye (B = 7.11, P < 0.05). VR-QoL in patients with bilateral corneal blindness was significantly impaired but improved after Fyodorov-Zuev (MICOF) KPro implantation. Improvement in VR-QoL was inversely associated with postoperative VA of the operative eye but positively correlated with preoperative VA of the fellow eye. This study affirmed that Fyodorov-Zuev (MICOF) KPro was an effective alternative for patients with corneal blindness with respect to VR-QoL.

Nanohydroxyapatite Coating Attenuates Fibrotic and Immune Responses to Promote Keratoprosthesis Biointegration in Advanced Ocular Surface Disorders.

Keratoprosthesis (KPro) implantation is frequently the only recourse for patients with severe corneal disease. However, problems arise due to inadequate biointegration of the KPro, particularly the PMMA optical cylinder, such as tissue detachment, tissue melting, or eye-threatening infection in the interface. Here, using the AuroKPro as a model prosthesis, a surface functionalization approach─coating the optical cylinder with nanohydroxyapatite (nHAp)─was trialed in rabbit eyes with and without a proceeding chemical injury. In chemically injured eyes, which simulated total limbal epithelial stem cell deficiency, clear benefits were conferred by the coating. The total modified Hackett-McDonald score and area of tissue apposition differences 12 weeks after implantation were 5.0 and 22.5%, respectively. Mechanical push-in tests revealed that 31.8% greater work was required to detach the tissues. These differences were less marked in uninjured eyes, which showed total score and tissue apposition differences of 2.5 and 11.5%, respectively, and a work difference of 23.5%. The improved biointegration could be contributed by the attenuated expression of fibronectin (p = 0.036), collagen 3A1 (p = 0.033), and α-smooth muscle actin (p = 0.045)─proteins typically upregulated during nonadherent fibrous capsule envelopment of bioinert material─adjacent to the optical cylinders. The coating also appeared to induce a less immunogenic milieu in the ocular surface tissue, evidenced by the markedly lower expression of tear proteins associated with immune and stimulus responses. Collectively, the level of these tear proteins in eyes with coated prostheses was 1.1 ± 13.0% of naïve eyes: substantially lower than with noncoated KPros (246.5 ± 79.3% of naïve, p = 0.038). Together, our results indicated that nHAp coating may reduce the risk of prosthesis failure in severely injured eyes, which are representative of the cohort of KPro patients.

Incidence, risk factors, and treatment of retroprosthetic membranes following Boston keratoprosthesis eyes and the impact of glaucoma surgery.

To assess incidence, risk factors, and treatment of retroprosthetic membrane (RPM) formation in eyes following Boston keratoprosthesis (Kpro) implantation and their correlation with glaucoma drainage device placement (GDD). A retrospective review was performed on eyes that underwent Kpro type I or II implantation between 2005 and 2020 at a tertiary academic center. Multiple variables were collected including preoperative characteristics, presence of RPM, management of RPM, and outcomes including corrected visual acuity (VA). A Fischer's exact test was used to evaluate the significance of risk factors of RPM formation and an odds ratio was calculated for each possible risk factor. A Mann-Whitney U test was used to evaluate comparisons between outcomes and qualitative analyses. Of the 87 eyes identified, 37 (43%) developed an RPM within an average of 1.5years (range, 31days-7.5years) following Kpro implantation. Mean follow-up duration was 4.3years. Eyes that developed RPM had significantly worse preoperative VA compared to those that did not (logMAR 2.55 vs. 2.28, p = 0.022). The mean number of prior penetrating keratoplasty procedures trended higher in eyes that developed RPM (2.46 vs. 2.18, p = 0.44) but was not significant. GDD placement after Kpro implantation was associated with an increased risk of RPM formation (RR = 1.69 p = 0.026). Of the 37 eyes that developed an RPM following Kpro, 17 (47%) were treated with Nd:YAG laser, and four of those 17 (21%) also underwent pars plana vitrectomy (PPV). Seven of 37 eyes (19%) underwent PPV without Nd:YAG. Comparisons between RPM occurrence and final VA were not significant. The incidence of RPM formation following Kpro implantation was 43%. Eyes that developed RPM had significantly worse preoperative VA. GDD placement after Kpro implantation increased the risk of developing RPM. Final VA and occurrence of RPM were not significantly different between the Nd:YAG and PPV treatment groups.

Ten-Year Outcome of Boston Type I Keratoprosthesis Surgery at a Tertiary Care Center.

The aim of this study was to report long-term outcomes of patients who have undergone Boston type I keratoprosthesis (KPro) surgery. This study was a retrospective review. Inclusion criteria were KPro surgery between 2006 and 2012 and at least 10 years of follow-up. Demographics, ocular history, surgery indication, clinical variables, and postsurgical outcomes were recorded. Descriptive statistical analysis was performed. We identified 75 patients with KPro implantation, and 17 patients with at least 10 years of follow-up (median = 11.1 years; range, 10.0-12.8 years) were included. Of 17 eyes, 11 (64.8%) had their original device in situ, 3 (17.6%) had their second device in situ, 1 (5.9%) had the device removed and replaced with a donor keratoplasty, and 2 (11.8%) were enucleated. At the last follow-up, 11 eyes (64.7%) were able to maintain improvement in vision, 5 (29.4%) had worsened vision, 1 (5.9%) had stable vision, and 9 (52.9%) had visual acuity <Snellen 20/200. Major complications included infectious keratitis (n = 5, 29.4%), hypotony (n = 4, 23.5%), retinal detachment (n = 4, 23.5%), endophthalmitis (n = 2, 11.8%), and retroprosthetic membrane (n = 7, 50%). In addition, 15 eyes (88.2%) required glaucoma surgery. All but 1 eye lost best-ever visual acuity with 9 eyes (52.9%) because of glaucoma progression. KPro had an acceptable retention proportion and remains a viable option for eyes at high risk of failure with donor keratoplasty. However, subsequent surgeries are commonly performed postoperatively to manage complications. Glaucoma seems to be the main etiology of irreversible vision loss.

Electrospun borneol/PVP antibacterial coating for postoperative management of keratoprosthesis implantation

ABSTRACT Keratoprosthesis (K-Pro) implantation and postoperative recovery often lead to severe ocular infections called keratoprosthesis-associated infections (KPAI). Antibiotics are commonly used; however, prolonged antibiotic use can lead to bacterial resistance and disrupt microbial balance in the eye. Borneol provides possibilities for developing antibiotic-independent antimicrobial K-Pro. Therefore, the development of an antibiotic-independent self-antimicrobial K-Pro is crucial for postoperative management. Herein, electrospinning technology was employed to fabricate a soluble borneol-based antibacterial coating on K-Pro surfaces for postoperative management of keratoprosthesis implantation. The modified K-Pro exhibited a distinctive nanofibrous morphology (100% borneol release ratio within 125 min), surface antibacterial properties (Escherichia coli: 2%, Staphylococcus aureus: 6%), biocompatibility, and negligible cytotoxicity towards epithelial cells. This study aimed to explore the potential application of camphor-based electrospun coatings in the field of K-Pro infection resistance, thereby providing novel strategies and material foundations for the effective postoperative management of KPAI.

Visual outcomes of primary keratoprosthesis implantation in transplant-naïve eyes.

Primary keratoprosthesis (Kpro) implantation may be indicated in eyes that have an expected poor prognosis following initial penetrating keratoplasty, such as eyes with limbal stem cell deficiency (LSCD). We compare visual outcomes of eyes undergoing primary Kpro to eyes that had a secondary Kpro following penetrating keratoplasty. Retrospective review of all patients who had Kpro implantation at a tertiary academic medical center from 2005-2020. Among those, eyes that had undergone primary Kpro implantation without a history of prior corneal transplantation were also identified. Eighty-four eyes of 77 patients that had undergone Kpro implantation were identified. Of those 84, 12 eyes (21.4%) of 12 patients were receiving primary Kpro since they were corneal transplant-naïve. Among individuals undergoing primary Kpro implantation compared to secondary Kpro implantation, the most common underlying diagnoses were limbal stem cell deficiency (41.7% vs 10.0%, p = 0.01304), corneal scarring not otherwise specified (25.0% vs 2.86%, p = 0.02077), and neurotrophic cornea (16.7% vs 2.86%, p = 0.1002). Eyes undergoing primary Kpro implantation had similar mean visual acuity to eyes undergoing secondary Kpro preoperatively (20/2118 vs 20/3786, p = 0.271), 3 months postoperatively (20/264 vs 20/758, p = 0.174), and at final follow up (average 3.06 years, 20/907 vs 20/3446, p = 0.070). Average follow-up time and rates of glaucoma, endophthalmitis, retroprosthetic membrane, and retinal detachment did not significantly differ between groups (all p > 0.05). All eyes that progressed to no light perception (n = 13) had undergone secondary Kpro implantation. Visual acuity outcomes were similar between primary Kpro implantation and secondary Kpro implantation. Eyes that underwent primary Kpro implantation trended toward better postoperative VA at final follow-up than secondary Kpro eyes.

Glaucoma after penetrating keratoplasty and keratoprosthesis

To compare visual and glaucoma outcomes in patients with known glaucoma after a penetrating keratoplasty (PKP) or a Boston Keratoprosthesis Type 1 (KPro) as a second corneal replacement procedure. Retrospective interventional case series. Charts of 141 eyes that underwent either a PKP or KPro at the Centre hospitalier de l'Université de Montréal after one failed PKP from 2008 to 2020 were reviewed. Forty-six eyes with preoperative glaucoma were included. Data collected included demographics, indication for the initial surgery, best corrected visual acuity (BCVA), concurrent ocular disorders, number of glaucoma medications, need for glaucoma surgery, cup-to-disc ratios (CDRs), mean RNFL thickness, and visual field (VF) characteristics. Primary outcomes were glaucoma progression trends. Secondary outcomes were visual outcomes and need for additional procedures. Mean follow-up was 4.7years for the PKP and 7.3 for the KPro group (P<0.007). 30.6% of PKP compared to 70.5% of KPro patients were diagnosed with glaucoma preoperatively. Glaucoma worsened similarly in both groups; this is based on an analysis of the number of glaucoma medications, CDR, need for glaucoma surgery, and characteristic VF changes. Patients in the PKP group required significantly more regrafts than patients in the KPro group (31.8 vs. 8.3%; P=0.045). A preoperative diagnosis of glaucoma does not preclude KPro implantation. In glaucomatous eyes, the disease progressed similarly in both groups. Since both procedures increase the risk of worsening glaucoma, close follow-up is recommended. KPro may decrease the need for further corneal transplantation surgery.

RETRACTED: Résultats à long terme de la kératoprothèse de Boston de type I au Canada

To evaluate long-term visual outcomes of Boston type I keratoprosthesis (KPro) surgery and identify risk factors for visual failure. Single surgeon retrospective cohort study including 85 eyes of 74 patients who underwent KPro implantation to treat severe ocular surface disease, including limbal stem cell deficiency, postinfectious keratitis, aniridia and chemical burns. Procedures were performed at the Centre hospitalier de l'Université de Montréal from October 2008 to May 2012. All patients with at least 5 years of follow-up were included in the analysis, including eyes with repeated KPro. Main outcome measures were visual acuity (VA), visual failure, defined as a sustained VA worse than the preoperative VA, postoperative complications, and device retention. Mean follow-up was 7.2±1.3 years (±SD). Mean VA was 2.1±0.7 (logarithm of minimal angle resolution) preoperatively and 1.9±1.2 at last follow-up. In total, 2.4% of patients had VA better than 20/200 preoperatively vs. 36.5% at last follow-up. Maintenance of improved postoperative VA was seen in 61.8% of eyes at 7 years. Preoperative factors associated with visual failure were known history of glaucoma (HR=2.7 [1.2 to 5.9], P=0.02) and Stevens-Johnson syndrome (HR=7.3 [2.5 to 21.4], P<0.01). Cumulative 8-year complication rates were 38.8% retroprosthetic membrane formation, 25.9% hypotony, 23.5% new onset glaucoma, 17.6% retinal detachment, 8.2% device extrusion and 5.9% endophthalmitis. The majority (91.8%) of eyes retained the device 8 years after implantation. Nearly two-thirds of patients exhibited improved VA 7 years after KPro implantation. Preoperative risk factors for visual failure were known glaucoma and Stevens-Johnson syndrome.

Microbial Infections After Boston Keratoprosthesis: A Case Series

Purpose: This article presents a case series of microbial keratitis in eyes that underwent Boston keratoprosthesis implantation. Methods: A thorough examination of medical records and microbiology results was conducted for patients who experienced microbial keratitis subsequent to Boston keratoprosthesis (KPro) implantation from July 2019 to July 2023. Results: The review included 3 eyes of 3 distinct patients. In case 1, a patient with a history of chemical burns in the right eye underwent type I KPro implantation. Infectious keratitis, caused by Corynebacterium amycolatum, developed 9 years post-implantation. Despite the keratitis, the KPro remained in place, and treatment with vancomycin and ceftazidime agents, along with a C-collar full-thickness corneal graft for corneal melt, was administered. In case 2, Streptococcus pneumoniae-induced keratitis occurred 2 months following a type I KPro implantation. The infiltration resolved entirely after 4 weeks of topical and systemic antimicrobial treatment. Case 3 involved a patient with a history of Stevens-Johnson syndrome who underwent type II KPro implantation with autologous auricular cartilage reinforcement in the left eye. Bacterial keratitis and endophthalmitis caused by Streptococcus mitis/oralis developed 2 years after the surgery, ultimately resulting in phthisis. Conclusions: Both C. amycolatum and S. mitis/oralis can breach commensalism barriers, leading to opportunistic infections in eyes with implanted keratoprosthesis and compromised ocular surfaces. Post-keratoprosthesis microbial keratitis remains a significant concern and is often associated with adverse outcomes.

Intra-operative optical coherence tomography in corneal lamellar graft reinforcement for Boston type I keratoprosthesis corneal melt.

Corneal melt is a sight-threatening complication of Boston type 1 keratoprosthesis (KPro). Severe corneal melt may result in hypotony, choroidal hemorrhage, and even spontaneous extrusion of the KPro, which may lead to a poor visual prognosis. Lamellar keratoplasty is one surgical option for the management of mild corneal melt, especially when a new KPro is not available. Herein, we present a new surgical technique application, intra-operative optical coherence tomography (iOCT) for the management of cornea graft melt after Boston type 1 KPro implantation. The visual acuity and the intra-ocular maintained stable at 6 months post-operatively, and the KPro remained in place without corneal melting, epithelial ingrowth, or infection. iOCT may prove to be a real-time, non-invasive, and accurate treatment for corneal lamellar dissection and suturing beneath the anterior plate of the KPro, which can effectively help the surgeon to make surgical decisions and reduce post-operative complications.

Incidence and risk factors for glaucoma development and progression after corneal transplantation.

To assess the cumulative incidence and risk factors for glaucoma development and progression within 1-2 years following corneal transplant surgery. Retrospective cohort study. Patients undergoing penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), Descemet stripping endothelial keratoplasty (DSEK), Descemet membrane endothelial keratoplasty (DMEK), Boston keratoprosthesis type I (KPro) implantation, or endothelial keratoplasty (DSEK or DMEK) under previous PK (EK under previous PK) at one academic institution with at least 1 year of follow-up were included. Primary outcome measures were cumulative incidence of glaucoma development and progression after corneal transplant, in patients without and with preoperative glaucoma, respectively. Risk factors for glaucoma development and progression were also assessed. Four hundred and thirty-one eyes of 431 patients undergoing PK (113), DALK (17), DSEK (71), DMEK (168), KPro (35) and EK under previous PK (27) with a mean follow-up of 22.9 months were analyzed. The 1-year cumulative incidence for glaucoma development and progression was 28.0% and 17.8% in patients without and with preoperative glaucoma, respectively. In a Cox proportional hazards analysis, DSEK surgery, KPro implantation, average intraocular pressure (IOP) through follow-up and postoperative IOP spikes of ≥30 mmHg were each independently associated with glaucoma development or progression (p < 0.04 for all). A significant proportion of patients developed glaucoma or exhibited glaucoma progression within 1 year after corneal transplantation. Patient selection for DSEK may partly explain the higher risk for glaucoma in these patients. Postoperative IOP spikes should be minimized and may indicate the need for co-management with a glaucoma specialist.

RETINAL DETACHMENT IN EYES WITH BOSTON TYPE 1 KERATOPROSTHESIS: Surgical Techniques and Mid-Term Outcomes.

To evaluate the mid-term outcomes of pars plana vitrectomy performed for retinal detachment (RD) repair after Boston Type 1 keratoprosthesis (KPro) implantation. Retrospective review of medical records of KPro implanted at the Stein Eye Institute presenting with RD and treated by pars plana vitrectomy. Functional success was defined as a postoperative visual acuity maintained within 2 Snellen lines of the corrected distance visual acuity measured before the development of the RD (baseline) and anatomical success as an attached retina after the pars plana vitrectomy. Kaplan-Meyer survival analyses were performed. Among the 224 KPro performed, 28 (15.2%) RD were identified; of which, 21 (9.4%) were included. The mean follow-up was 42.5 ± 27.3 months. Vitreoretinal proliferation was present in 18 of 21 eyes (85.7%). Surgical techniques were adapted to the complex anterior segment anatomy of KPro eyes. Anatomical success was achieved in 18 of 21 eyes (85.7%). Functional success occurred in 17 of 21 eyes (81.0%), and 5 of 21 eyes (23.8%) reached 20/400 or better visual acuity at the final follow-up. The KPro was retained in 11 in 21 eyes (52.4%). The retention rate decreased from 94.7% at 1 year to 53.5% at 5 years. The most frequent complications were retroprosthetic membrane (47.6%) and corneal melt (23.8%). Modified pars plana vitrectomy techniques resulted in relatively good mid-term anatomical, functional, and retention rate outcomes, given the severity of RD at presentation and the numerous preoperative comorbidities of KPro eyes.

Challenges of Glaucoma Management in Patients with Type I Boston Keratoprosthesis.

Type I Boston keratoprosthesis is implanted in patients with severely diseased eyes who are considered poor candidates for traditional keratoplasty. Glaucoma is considered a major visual comorbidity following the implantation of type I Boston keratoprosthesis (KPro). Eyes that receive a Boston KPro are at high risk of progression of pre-existing glaucoma and the development of de novo glaucoma. Both complications can limit best-corrected visual acuity postoperatively. Diagnosis and surveillance for glaucoma in KPro eyes are fundamental to mitigate the risk of visual morbidity. However, managing these patients presents several challenges. The diagnosis of glaucoma after KPro implantation is usually hindered by inaccurate intraocular pressure (IOP) measurements and unreliable ophthalmic investigations such as visual field testing and optical coherence tomography (OCT) of the retinal nerve fiber layer (RNFL). In these eyes, medical management of glaucoma with topical medications is usually insufficient, and glaucoma surgery is usually warranted either prior to or during KPro implantation. Options for glaucoma surgery include glaucoma drainage device (GDD) and cyclodestructive procedures. The aim of this article is to highlight the incidence, pathophysiology, diagnosis, and management options of glaucoma in eyes that have undergone type I Boston keratoprosthesis.

Glaucoma Evaluation and Management in Eyes With Boston Type 1 and Aurolab Keratoprostheses in an Indian Cohort.

The purpose of this study was to evaluate glaucoma and its management in eyes with Boston type 1 keratoprosthesis (Boston-Kpro) and Aurolab keratoprosthesis (Auro-Kpro) in an Indian cohort. This retrospective comparative case series included 175 eyes of 175 patients who underwent type 1 keratoprosthesis from 2009 until 2017; type 1 Boston-Kpro was performed in 107 eyes (107 patients) and Auro-Kpro in 68 eyes (68 patients). The eyes with <1-month follow-up were excluded, and hence, for the analysis of glaucoma, 62 eyes with Auro-Kpro and 99 eyes with Boston-Kpro were included. Progression was defined as the worsening of optic disc damage/progression by visual field/uncontrolled IOP needing additional medications or glaucoma surgery. The post-Kpro mean follow-up was 1.8 ± 1.7 years. After Kpro, overall glaucoma was noted in 61% of eyes (98/161). Preexisting glaucoma was noted in 28% of eyes (45/161), postoperative glaucoma was noted in 33% of eyes (53/161), and 39% of eyes (63/161) did not have glaucoma. Among those with preexisting glaucoma, 49% of eyes (22/45) progressed after Kpro implantation. The proportion of eyes with glaucoma in Auro-Kpro (56.5% of eyes) and Boston-Kpro (63.6% of eyes) was similar (P = 0.46). The Kaplan-Meier curve for cumulative survival (Kpro-retention rate) was similar in eyes with and without glaucoma (83% vs. 76% at 1 year, 72% vs. 70% at 2 years; P = 0.65). A higher number of prior intraocular surgeries (P = 0.04) was significantly associated with risk for postoperative glaucoma. Glaucoma was seen in more than half of the eyes with type 1 keratoprosthesis. The presence of glaucoma did not seem to affect the retention of keratoprosthesis. A high rate of postoperative glaucoma and the progression of preexisting glaucoma need close monitoring and appropriate management.

Fungal seeding of bandage contact lens with no underlying corneal invasion of boston keratoprosthesis

Infectious keratitis develops in 13.6% of eyes after keratoprosthesis (Kpro) implantation, with a similar rate of culture-positive bacterial and fungal keratitis. We report a case of 73-year old man who underwent Boston Kpro implantation in the left eye 2 years back. He presented with conjunctival discharge and a whitish growth over the bandage contact lens (BCL) for the past 2 weeks. Slit-lamp examination showed a whitish elevated growth with surrounding diffuse brownish feathery seeding all over the BCL. The BCL which was sent for culture grew fungus. The underlying Kpro was clear with no evidence of any active infiltrate. The patient was started on topical antifungal eye drops and was followed up for 12 months with no recurrence of infection. Educating the patient to be sensitive and to report immediately if they note any abnormality is as important as cleaning or replacing the BCL on a regular basis.

Clinical Experience in Patients with Ocular Burns Treated with Boston Type I Keratoprosthesis Implantation with or Without Prophylactic Ahmed Glaucoma Valve Implantation.

IntroductionTo compare outcomes in eyes with ocular burns following Boston Type I keratoprosthesis (KPro) implantation with and without prophylactic pars plana tube surgery.MethodsA retrospective review of patients with ocular burns who underwent KPro surgery at Zhongshan Ophthalmic Center was performed. Twenty-six eyes of 26 patients without a preoperative diagnosis of glaucoma before KPro surgery met the inclusion criteria. Preoperative glaucoma was defined as a history of a durable elevated intraocular pressure (IOP) ≥ 25 mmHg at different time points, which resulted in the introduction of anti-glaucoma medication or surgical intervention. Sixteen eyes underwent KPro alone (Group 1), and 10 eyes received KPro with prophylactic pars plana tube surgery (Group 2).ResultsGroup 1 and Group 2 were similar in the proportions of the ocular burn type and preoperative clock hours of peripheral anterior synechiae by ultrasound biomicroscopy (1.88 ± 1.63 vs. 2.30 ± 1.83; P = 0.54). Before KPro surgery, 62.5% of eyes in Group 1 and 50.0% of eyes in Group 2 had intraocular surgeries (P = 0.53). The follow-up time was 18 months. At the final follow-up time, the two groups had similar visual acuity (1.34 ± 0.87 logMAR, 1.03 ± 0.71 logMAR; P = 0.35) and eyes with a C/D ratio ≥ 0.8 (7/16, 2/10; P = 0.21), but more eyes in Group 1 developed glaucoma de novo than eyes in Group 2 (62.5%, 20%; P = 0.04) and had undergone secondary glaucoma surgery after KPro implantation (7/16 vs. 0/10; P = 0.02).ConclusionIn eyes injured with ocular burns, KPro implantation with prophylactic pars plana tube surgery may be a feasible option to rehabilitate visual acuity and decrease the incidence of glaucoma de novo.

POSTOPERATIVE POSTERIOR SEGMENT COMPLICATIONS AFTER BOSTON TYPE 1 KERATOPROSTHESIS: Incidence, Risk Factors, and Intermediate-Term Outcomes.

To identify the incidence of, risk factors for, and outcomes of posterior segment complications (PSC) after Boston Type 1 keratoprosthesis (KPro) implantation. Retrospective, consecutive case series of KPro procedures at the Stein Eye Institute. Data regarding ocular history, intraoperative details, postoperative management, and outcomes were collected. Eyes with at least one PSC (PSC group) were compared with eyes without PSC (No PSC group), and risk factors for PSC were determined. Ninety-five PSC occurred in 69/169 eyes (40.8%), at a mean of 20.1 months after KPro implantation (0.01 complications/eye month). The median follow-up after KPro implantation was 44.0 months (range 3.0-174.4). The most common PSC were epiretinal membrane (16.6%), cystoid macular edema (12.4%), vitritis (11.2%), and retinal detachment (9.5%). Previous retinal detachment repair, concomitant intraocular lens removal, postoperative aphakia, and vitritis were risk factors for retinal detachment. Postoperative infectious keratitis was a risk factor for epiretinal membrane, cystoid macular edema, and vitritis. The posterior segment complication group had a significantly higher rate of eyes failing to maintain visual acuity ≥20/200 (HR = 2.28; 95% CI = 1.35-3.85) and KPro retention failure rate (HR = 1.66; 95% CI = 0.95-2.91). Posterior segment complications occur in approximately 40% of eyes after KPro implantation, resulting in reduced visual outcomes and KPro retention.

Ocular Surface Preparation Before Keratoprosthesis Implantation.

IntroductionThis study aimed to evaluate the surgical treatment results for conjunctival limbal autograft (CLAU) and keratolimbal allograft (KLAL) in various types of limbal stem cell deficiency (LSCD) etiologies performed in order to achieve a stable ocular surface prior to KPro implantation.MethodsWe analyzed the outcomes of the surgical treatment of 43 eyes of 39 patients with LSCD as an initial treatment preparing patients’ ocular surface for KPro implantation. The most common causes were ocular trauma (50.7%), mainly alkali burns (77%); autoimmune causes, mainly ocular cicatricial pemphigoid (OCP; 17.4%); infection (15.9%) including Lyell’s syndrome/Stevens–Johnson syndrome (LS/SJS; 16%). In all 17 eyes operated on with CLAU, this procedure was performed once. Similarly, one uncomplicated KLAL procedure in one eye was performed in 10 women and 19 men. In another one woman and three men, KLAL was performed in both eyes. In one man with Lyell’s syndrome, the KLAL operation was performed three times in one eye. Follow-up was at least 12 months.ResultsVisual acuity (VA) improved in 17 eyes (31%) and remained unchanged in 38 eyes (69%). VA improved from light perception to hand movements in three eyes (16%) from the CLAU group of patients and eight eyes (15%) from the KLAL group; VA improved from hand movements to finger counting in two eyes (12%) post CLAU and two eyes (4%) post KLAL operation. The most common complication of surgical treatment was persistent epithelial defect that was refractory to medical treatment in 32 eyes (58%), 5 eyes post CLAU and 27 post KLAL. Corneal conjunctivalization (19%) and neovascularization (29%) were present on the corneal edge of the graft. Symblephara recurred within 3 months in nine eyes (17.3%) after KLAL, including four eyes that had been chemically burned and five eyes with LS/SJS.DiscussionPretreatment with CLAU or KLAL procedures in severely damaged ocular surfaces allows the ocular surface to be prepared for safe KPro implantation with sufficient tissue surroundings with less conjunctivalization and deeper conjunctival fornices.

Remote Surgeon Virtual Presence: A Novel Telementoring Method for Live Surgical Training.

Purpose:We describe the first known use of telementoring in corneal surgery and technology combining a 3-dimensional microscope system, 5G live streaming technology, group chat software, and a virtual reality headset for intercontinental surgical supervision.Methods:Three surgeons in Toronto were proctored by a surgeon in Israel in the implantation of a novel keratoprosthesis device (CorNeat KPro; Ra'anana, Israel) into cadaver eyes. In Toronto, the NGENUITY platform (Alcon) transmitted high-definition, 3-dimensional images to the proctor in Israel who viewed the live video through a GOOVIS Virtual Reality headset with subsecond latency. This was made possible by the LiveU technology (Hackensack, NJ), which is a portable device to increase the bandwidth of transmission. The primary outcome was the successful completion of CorNeat KPro implantation. After each procedure, all surgeons completed a Likert scale questionnaire that assessed opinions on telementoring.Results:All participants implanted the CorNeat KPro device. There was significant satisfaction reported. A total cumulative score from the questionnaire was 149 of 150 from the operating surgeons, with a score of 135 of 150 by the proctor. All felt that there was excellent AV quality with no lag time and recommended the technology.Conclusions:Telementoring is a promising tool that can traverse large distances for ophthalmic education.

Assessment of the Role and Timing of Glaucoma Surgery in Boston Keratoprosthesis Type 1 Patients

To determine the role and optimal timing of glaucoma surgery in relation to Boston keratoprosthesis type 1 (KPro) implantation. Retrospective, comparative, nonrandomized clinical study. Single-center study of a total of 100 eyes (100 patients) implanted with a KPro between 2008 and 2017, and diagnosed with glaucoma before or after KPro. Patients were separated into 2 groups: those with preexisting glaucoma and those who developed de novo glaucoma after KPro. Groups were then divided based on whether patients were medically or surgically managed. Glaucoma surgery included glaucoma drainage device (GDD) implantation, trabeculectomy, and cyclophotocoagulation (CPC). Primary outcomes included best-corrected visual acuity (BCVA), glaucoma progression, and complications. Differences in outcomes were compared using parametric and nonparametric tests, as well as log-rank test to compare time-to-outcome events. Among 72 eyes with preexisting glaucoma, 27 (38%) had glaucoma surgery before KPro (18 GDD), whereas 45 (62%) were medically managed only. Among the latter, 19 (42%) needed glaucoma surgery post-KPro (16 GDD). Among 28 eyes with de novo glaucoma, 12 (43%) had glaucoma surgery post-KPro (9 GDD). For eyes with preexisting glaucoma, glaucoma progression was greater with glaucoma surgery performed post-KPro (100%) compared with pre-KPro (74%, P=.016) and to medical management (54%, P=.002). No increase in complications were observed with glaucoma surgery compared to medications only (P > .05), whereas fewer eyes maintained a BCVA of 20/200 or better over time with medical management (P=.013). Eyes with de novo glaucoma had similar progression, BCVA, and complications between medical and surgical care (P > .05). Glaucoma surgery should be performed before or at the same time as KPro implantation in eyes with preexisting glaucoma. Complication rates are not increased when glaucoma surgery is performed in KPro eyes with either preexisting or de novo glaucoma. To ensure optimal glaucoma control, glaucoma surgery should be performed as early as possible in KPro eyes with good visual potential.