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

PURPOSE: 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). METHODS: 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. RESULTS: Of the 87 eyes identified, 37 (43%) developed an RPM within an average of 1.5 years (range, 31 days-7.5 years) following Kpro implantation. Mean follow-up duration was 4.3 years. 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. CONCLUSIONS: 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.

Boston Keratoprosthesis type 1 (KPro) without contact lens wearing in end-stage corneal disease: The APEC experience.

PURPOSE: To report the visual outcomes and survival analysis of keratoprosthesis without contact lens wearing in a tertiary eye care hospital in Mexico City, Asociación Para Evitar La Ceguera (APEC, Coyoacán, México). DESIGN: Retrospective cohort with survival analysis. PARTICIPANTS: Twenty-three eyes (22 patients) received KPro type 1 between 2015 and 2020 with a follow-up time of three years. METHODS: We included analyzed data about past medical history, preoperative diagnosis, best-spectacle visual acuity (BSCVA), postoperative complications and retention rate. Univariate, bivariate and survival analysis were performed and reported. RESULTS: The mean age was 58 ± 13.5 years (SD). 60.86% were male patients (14 eyes). Twelve-eyes (52%) achieved a BSCVA of 20/200 or better in the first and second year of follow-up. At 3 years, only 35% achieved 20/200 or better (BSCVA). Retention rate of Boston type 1 KPro was 87% (20 eyes) at 3 years follow-up. The most common complication was retroprosthetic membrane (RPM) which occurred in 9 eyes (39.1%), followed by corneal melting in 7 eyes (30.4%). CONCLUSIONS: We report the results of a retrospective cohort of twenty-three eyes (22 patients) who were implanted with a Boston type 1 KPro without contact lens wearing to treat corneal blindness. BSCVA improved significantly in most patients achieving 20/200 or better at the 2-year follow-up. Retention rate was 87%, with the presence of RPM as the most common complication.

Outcomes of Boston Keratoprosthesis Type I Implantation in Poland: A Retrospective Study on 118 Patients.

Background: Boston Keratoprosthesis Type I (BI-KPro I) is a synthetic cornea that can be used to restore vision in patients with corneal blindness. This retrospective study evaluated the outcomes of BI-KPro implantation in 118 patients. Material: The mean age of the patients was 56.76 ± 14.24 years. Indications for keratoprosthesis implantation were as follows: graft failure, 47 (39.83%); ocular burn, 38 (32.20%); neurotrophic keratopathy, 11 (9.32%), mucous membrane pemphigoid 9 (7.67%); autoimmune, 6 (5.08%); Stevens-Johnson syndrome, 4 (3.39%); and aniridia (2.54%). Methods: The surgeries were performed between March 2019 and June 2022 at a single clinical center in two locations. The postoperative visual acuity, complications, and need for additional surgical procedures were analyzed. Results: The Best Corrected Visual Acuity before surgery was 0.01 ± 0.006. After one year (V1), it was 0.30 ± 0.27; at two years (V2), it was 0.27 ± 0.26; and at three years (V3), it was 0.21 ± 0.23. The percentage of patients with visual acuity better than 0.1 on the Snellen chart was 37.29% after 1 year, 49.35% after 2 years, and 46.81% after 3 years of follow up. The most common complications were glaucoma (78 patients; 66.1%), corneal melting (22 patients; 18.6%), and retroprosthetic membranes (20 patients; 17.0%). Conclusions: The BI-KPro can significantly improve visual acuity. The worst long-term results were obtained in the group of patients with autoimmune diseases; therefore, careful consideration should be given to implanting BI-KPro in this group. The high incidence of de novo glaucoma or the progression of pre-existing glaucoma suggests the need for careful monitoring.

Glaucoma after penetrating keratoplasty and keratoprosthesis.

PURPOSE: 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. DESIGN: Retrospective interventional case series. PARTICIPANTS: 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. METHODS: 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. RESULTS: Mean follow-up was 4.7 years 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). CONCLUSIONS: 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.

The historical development and an overview of contemporary keratoprostheses.

Corneal blindness is a major cause of ocular morbidity that affects 4.5 million people worldwide. Though penetrating keratoplasty is an excellent option for most patients with corneal blindness, there are various conditions for which corneal transplantation carries a low likelihood of success. In cases of multiple failed transplants, the keratoprosthesis, an artificial cornea, is a well-documented surgical option, though few models are commercially available. Keratoprostheses also provide a solution to those in developing areas of the world who do not have access to penetrating keratoplasty owing to limitations in the supply of corneal donor tissue. We summarize the history of keratoprostheses, examine the various keratoprosthesis models used across the globe, and highlight efforts to improve the accessibility and biointegration of keratoprosthesis through novel technological developments.

Timing of glaucoma treatment in patients with MICOF: A retrospective clinical study.

Purpose: To summarize and discuss the treatment and timing of glaucoma in patients with MICOF keratoprosthesis implantation to guide follow-up clinical treatment. Methods: The data of 39 eyes (39 patients) with the Moscow Eye Microsurgery Complex in Russia (MICOF) keratoprosthesis implantation in our hospital from 1 January 2002 to 31 December 2017 were collected, including patients with preexisting glaucoma and those who developed glaucoma de novo after MICOF. The sex, age, preoperative diagnosis, glaucoma surgery, keratoplasty, times of keratoplasty, best corrected visual acuity (BCVA) and final follow-up corrected visual acuity, visual field (VF) defect, and cup-to-disk ratio (CDR) were statistically analyzed. Results: Among 16 eyes with preexisting glaucoma, eight eyes underwent glaucoma surgery before MICOF, 4 eyes underwent glaucoma surgery combined with MICOF, and four eyes were managed medically. Among 23 eyes with de novo glaucoma, seven eyes were treated with surgery and 16 eyes were treated with medication only. A total of 9 (56.3%) eyes had corneal transplants with preexisting glaucoma, which was a higher percentage than that in the patients with de novo glaucoma (n = 5, 21.7%, P = 0.043). In both the preexisting glaucoma group and the de novo glaucoma group, the most common causes were alkali burns (56.3% of preexisting glaucoma and 43.5% of de novo glaucoma). There was no significant difference between the operation and initial visual acuity, postoperative visual acuity, BCVA, CDR, or VF defect. In the de novo glaucoma group, the final follow-up visual acuity of the glaucoma surgery group (1.56 ± 1.07) was worse than that of the mediation group (0.44 ± 0.53) (P < 0.017). Among the complications, the incidence of cornea melting in the patients treated with medications only (n=10) was significantly higher than that in the patients treated with glaucoma surgery (n = 0, P = 0.007), but there was no significant difference in the other complications. Conclusion: Among patients with MICOF, those patients who have undergone keratoplasty are more likely to develop glaucoma before surgery and glaucoma needs to be prevented. Surgical treatment can be selected according to the ocular surface condition in the patients with de novo glaucoma to reduce the occurrence of complications.

The Boston Keratoprosthesis-The First 50 Years: Some Reminiscences.

Millions of people worldwide are bilaterally blind due to corneal diseases including infectious etiologies, trauma, and chemical injuries. While corneal transplantation can successfully restore sight in many, corneal graft survival decreases in eyes with chronic inflammation and corneal vascularization. Additionally, the availability of donor cornea material can be limited, especially in underdeveloped countries where corneal blindness may also be highly prevalent. Development of methods to create and implant an artificial cornea (keratoprosthesis) may be the only option for patients whose eye disease is not suitable for corneal transplantation or who live in regions where corneal transplantation is not possible. The Boston Keratoprosthesis (B-KPro) is the most commonly implanted keratoprosthesis worldwide, having restored vision in thousands of patients. This article describes the initial design of the B-KPro and the modifications that have been made over many years. Additionally, some of the complications of surgical implantation and long-term care challenges, particularly complicating inflammation and glaucoma, are discussed.

The evolution of the modified osteo-odonto-keratoprosthesis, its reliability, and long-term visual rehabilitation prognosis: An analytical review.

An exhaustive search of the world's literature was performed to analyze all case reports and series on the modified osteo-odonto-keratoprosthesis (MOOKP) published up to January 2022. The demographic profile, the primary indication for surgery, surgical technique variations, postoperative medical management, long-term functional and anatomical outcomes, and intra- and postoperative complications were analyzed and compared. Additionally, some of the authors' (GI, VP, and GA) unpublished MOOKP cases were studied. An extensive literature search yielded 37 case series and case reports. Overall, 958 patients were analyzed. The most common indication for surgery was autoimmune disease (39.1%), closely followed by chemical injury (38.8%). The most common intraoperative complications (21.67%) included maxillofacial, vitreous hemorrhage/vitritis, and mucosal. The most common postoperative complications (78.4%) were lamina and oral mucosa-associated, secondary glaucoma, and choroid/retinal detachment. Follow-up periods ranged from one to 364 months (median: 36.7 months). Altogether, 78% of patients achieved a visual acuity of 20/400 or better at the end of the follow-up period, and 91.2% improved at least temporarily after MOOKP surgery. Mean anatomic success at the end-of-follow-up for all patients was 88.25% (range, 50-100%). The long-term anatomic and functional success of the MOOKP makes it a reliable option for visual rehabilitation in patients with bilateral corneal blindness and end-stage ocular surface disease. This review aims to describe the evolution of the MOOKP procedure, analyzing all published case series for its long-term reliability, visual and anatomical outcomes, complications, and future directions.

A Review of the Diagnosis and Treatment of Limbal Stem Cell Deficiency.

Limbal stem cell deficiency (LSCD) can cause significant corneal vascularization and scarring and often results in serious visual morbidity. An early and accurate diagnosis can help prevent the same with a timely and appropriate intervention. This review aims to provide an understanding of the different diagnostic tools and presents an algorithmic approach to the management based on a comprehensive clinical examination. Although the diagnosis of LSCD usually relies on the clinical findings, they can be subjective and non-specific. In such cases, using an investigative modality offers an objective method of confirming the diagnosis. Several diagnostic tools have been described in literature, each having its own advantages and limitations. Impression cytology and in vivo confocal microscopy (IVCM) aid in the diagnosis of LSCD by detecting the presence of goblet cells. With immunohistochemistry, impression cytology can help in confirming the corneal or conjunctival source of epithelium. Both IVCM and anterior segment optical coherence tomography can help supplement the diagnosis of LSCD by characterizing the corneal and limbal epithelial changes. Once the diagnosis is established, one of various surgical techniques can be adopted for the treatment of LSCD. These surgeries aim to provide a new source of corneal epithelial stem cells and help in restoring the stability of the ocular surface. The choice of procedure depends on several factors including the involvement of the ocular adnexa, presence of systemic co-morbidities, status of the fellow eye and the comfort level of the surgeon. In LSCD with wet ocular surfaces, autologous and allogeneic limbal stem cell transplantation is preferred in unilateral and bilateral cases, respectively. Another approach in bilateral LSCD with wet ocular surfaces is the use of an autologous stem cell source of a different epithelial lineage, like oral or nasal mucosa. In eyes with bilateral LSCD with significant adnexal issues, a keratoprosthesis is the only viable option. This review provides an overview on the diagnosis and treatment of LSCD, which will help the clinician choose the best option amongst all the therapeutic modalities currently available and gives a clinical perspective on customizing the treatment for each individual case.

Vitreoretinal Complications in Boston Keratoprosthesis Type 1.

PURPOSE: To evaluate the incidence of vitreoretinal complications, treatment modalities, and the visual outcomes in a large cohort of eyes that underwent Boston Keratoprosthesis (KPro) implantation. DESIGN: Retrospective, interventional case series. METHODS: 132 eyes of 114 patients who underwent KPro implantation at the Centre Hospitalier de l'Université de Montréal from 2008 to 2017 were included with at least 1 year follow-up. Charts were reviewed and data was collected, including demographics, initial corneal indication for surgery, posterior segment complications, preoperative and postoperative visual acuity. RESULTS: Mean follow-up was 68.2 months and 61.4% of eyes developed postoperative vitreoretinal complications (VRC). The most common VRC was RPM formation (38.6%, n=51) followed by RD (15.2%, n=20), CME (12.1%, n=16), ERM (9.8%, n=13), endophthalmitis (9.1%, n=12), sterile vitritis (7.6%, n=10), vitreous hemorrhage (6.8%, n=9), choroidal detachment (3.0%, n=4) and central retinal vein occlusion (0.7%, n=1). BCVA improved in the no VRC group from 1.74 ± 0.33 logMAR to 1.33±0.83 logMAR and in the VRC group from 1.74±0.36 logMAR to 1.52±0.83 logMAR, without any statistically significant intergroup differences (p=0.231). RD was the only significant complication associated with poorer visual outcomes (p=0.001). CONCLUSION: Potentially blinding secondary complications occur in the majority of patients and frequent monitoring is necessary, specifically in the early and intermediate postoperative periods. This study evidenced significant improvements in visual outcomes of KPro eyes, including those that developed postoperative vitreoretinal complications.

Predictive factors of Boston Type I Keratoprosthesis outcomes: A long-term analysis.

PURPOSE: To study the long-term visual- and device retention-related outcomes and complications of the Boston Type I Keratoprosthesis (KPro). METHODS: Single-center, retrospective cohort study of all patients undergoing KPro implantation from February 2007 to April 2014 with at least 5 years of follow-up. RESULTS: 68 eyes from 65 patients underwent KPro implantation during the study period. At 5 and 10 years, the probability of maintaining or improving visual acuity (VA) was 75.0% and 66.7%, respectively, and the probability of KPro retention was 89.2% and 89.2%, respectively. Initial device retention rate at 10 years was significantly lower in those with underlying ocular surface disease (46.8% [30.6-63.2] vs 75.8% [61.0-90.7], P = 0.03), while other baseline characteristics showed no significant association. Final VA was more likely to be stable or improved in patients with fewer failed grafts (2 [1-6] vs 3 [1-6], P < 0.01), and a final VA of 20/200 or better was more likely in primary KPro eyes (44.8% [26.7-62.9] vs 19.4% [6.5-32.3], P = 0.03). Combined KPro-vitrectomy eyes were more likely to have stable or improved final VA than non-vitrectomy eyes (88.5% [76.2-100.0] vs 64.1% [49.1-79.1], P = 0.04). All complications had increasing incidence beyond 5 years; in particular, corneal melt, surgical glaucoma interventions, and endophthalmitis tended to have late presentations, with 79.0%, 78.6%, and 88.9% of these complications occurring beyond one year, respectively. CONCLUSIONS: KPro devices show favorable long-term visual and retention outcomes in select patients. Careful long-term, multidisciplinary follow-up is warranted to address potential complications.

Retroprosthetic membrane: A complication of keratoprosthesis with broad consequences.

Keratoprosthesis (KPro) devices have the remarkable ability to restore vision in patients suffering from corneal blindness who are poor candidates for traditional penetrating keratoplasty. However, eyes with KPro can experience various complications, including the development of retroprosthetic membrane (RPM). RPMs reduce visual acuity in patients due to physical obstruction of the visual axis, but studies have shown that RPM can also lead to a variety of other consequences, from melting of the corneal carrier graft to precipitating retinal detachments. Histopathologic studies have shown that RPMs are composed of elements from both the recipient and donor. The presence of myofibroblasts in RPMs imparts them with contractile properties, which can contribute to their downstream complications, including angle closure, hypotony, and retinal detachment. At present, there are limited treatments to combat the growth of RPM. Future therapies could include anti-metabolites and targeted anti-inflammatory treatments, as well as device coatings or textured device surfaces that can hinder RPM proliferation. The long-term success of KPro depends on devising an effective solution for preventing RPM growth.

Improving Value of Care: Cessation of Screening Urine Culture Prior to Orthopedic and Spinal Surgery.

OBJECTIVE: To assess the impact of cessation of screening urine cultures on surgical site infection (SSI) incidence in clinical practice. PATIENTS AND METHODS: Our study included patients undergoing hip replacement, knee replacement, spinal fusion, and laminectomy 12 months before (preintervention) and after (postintervention) cessation of preoperative screening urine cultures on June 1, 2017, at our institution. Urine cultures and urinalyses performed within 30 days before surgery during the 12 months before and after cessation were reviewed. SSI surveillance was performed in accordance with the methods of the National Healthcare Safety Network. RESULTS: A total of 2754 patients were included (1286 preintervention and 1468 postintervention). In the preintervention period, 1141 urine cultures were performed, compared to 153 in the postintervention period; 35 and 6 episodes of asymptomatic bacteriuria were treated, respectively. The occurrence of SSI did not differ noticeably between time periods (1.2% vs 0.7%, P=.24), and quarterly incidences of SSI were unchanged. The rate of SSI was significantly lower in the postintervention period for laminectomy (3.0% vs 0.3%, P=.02). CONCLUSION: An 86.6% (153 vs 1141) reduction in screening urine cultures over a 12-month period was associated with a reduction of 988 unnecessary urine cultures, an 82.8% (6 vs 35) decline in inappropriate antibiotic treatment of asymptomatic bacteriuria, and no increase in SSI incidence after hip replacement, knee replacement, spinal fusion, or laminectomy procedures. No value of screening urine cultures before clean surgery was identified.

Boston Type 2 keratoprosthesis- mid term outcomes from a tertiary eye care centre in India.

To analyse the anatomical and functional outcomes of Boston type II keratoprosthesis at a tertiary eye care centre in South India. Retrospective chart review of 10 patients operated with Boston keratoprosthesis Type 2 between Feb 2013 and June 2017 were analysed. Outcome measures analysed included, visual outcome, device retention and postoperative complications. The most common indication for surgery was SJS in 80% (8 of 10 eyes). Mean follow-up duration was 2.75 years (0.5-5 years, SD - 1.71, median 32 months) Postoperative visual acuity improved to better than 20/200 in 7 eyes and better than 20/30 in 6 eyes with device retention in 9 eyes at last follow-up. Pre-existing glaucoma was noted in 1 eye. RPM was noted in 1 eye, retinal detachment in 1 eye, endophthalmitis in 1 eye and sterile melt requiring kpro replacement in 1 eye. No progression or development of glaucoma was noted postoperatively in any eye . Boston type 2 keratoprosthesis is a viable option to restore vision in patients with end stage ocular surface disorders. Though the procedure can be associated with complications, early as well as late, our midterm outcome appears to be encouraging.

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

PURPOSE: To analyse the functional and anatomical outcomes of different types of keratoprostheses in eyes with retained silicone oil following vitreoretinal surgery. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Blood Levels of Tumor Necrosis Factor Alpha and Its Type 2 Receptor Are Elevated in Patients with Boston Type I Keratoprosthesis.

Purpose: Boston keratoprosthesis (KPro) patients are prone to glaucoma even with well-controlled intraocular pressure (IOP). Recent experimental data have shown that soluble tumor necrosis factor alpha (TNF-α) after ocular injury may contribute to progressive retinal damage and subsequent glaucoma. This study evaluates the blood plasma levels of soluble TNF-α, TNF receptors 1 (TNFR1) and 2 (TNFR2), and leptin in patients with Boston type I KPro. Methods: Venous blood samples were collected from KPro patients with glaucoma (KPro G, n = 19), KPro patients without glaucoma (KPro NoG, n = 12), primary angle closure glaucoma without KPro (PACG, n = 13), and narrow angles without glaucoma or KPro (NA, n = 21). TNF-α, TNFR1, TNFR2, and leptin levels were quantified using the enzyme-linked immunosorbent assay. Erythrocyte sedimentation rate (ESR) was assessed using the Westergren test. Patients with underlying autoimmune conditions or diabetes were excluded from the study. Results: All groups had similar age, body mass index (BMI), IOP, and ESR (p ≥ 0.11). The mean time from KPro surgery to blood draw was 5.3 ± 3.7 years. Compared to NA patients (0.72 ± 0.3 pg/ml), KPro G and KPro NoG patients had higher blood plasma levels of TNF-α (1.18 ± 0.58 pg/ml, p = 0.006; 1.16 ± 0.50 pg/ml, p = 0.04, respectively). Similarly, KPro G patients had higher blood plasma levels of TNFR2 (2768 ± 1368 pg/ml) than NA patients (2020 ± 435 pg/ml, p = 0.048). In multivariate analysis, KPro status remained positively associated with TNF-α levels (ß = 0.36; 95% confidence intervals [CI]: 0.14-0.58; p = 0.002) and TNFR2 levels (ß = 458.3; 95% CI: 32.8-883.7; p = 0.035) after adjusting for age, gender, BMI, glaucoma status, and ESR. TNFR1 and leptin levels were not significantly different in the study groups. Conclusions: We detected elevated serum levels of TNF-α and TNFR2 in KPro patients. Longitudinal studies are needed to establish TNF-α and TNFR2 as serum biomarkers related to KPro surgery. Abbreviations: BCVA: best corrected visual acuity; BMI: body mass index; CDR: cup-to-disc ratio; EDTA: ethylenediaminetetraacetic acid; ELISA: enzyme-linked immunosorbent assay; ESR: erythrocyte sedimentation rate; HVF: Humphrey visual field; IOP: intraocular pressure; KPro G: keratoprosthesis with glaucoma; KPro NoG: keratoprosthesis without glaucoma; KPro: keratoprosthesis; MD: mean deviation; NA: narrow angle; non-KPro: without keratoprosthesis; PACG: primary angle closure glaucoma; RNFL: retinal nerve fiber layer; TNF-α: tumor necrosis factor alpha; TNFR1: tumor necrosis factor receptor 1; TNFR2: tumor necrosis factor receptor 2.

Detection of laminar resorption in osteo-odonto-keratoprostheses.

PURPOSE: To compare the clinical examination and computerized tomography (CT) scanning methods for the detection of laminar resorption in eyes with osteo-odonto-keratoprosthesis (OOKP). METHODS: Patients who developed laminar resorption after OOKP surgery and had at least one CT scan of the lamina during the follow-up were included. Case records and CT images and reports were retrospectively reviewed. Each lamina of the eye was regarded as a case. The imaging and clinical data were collected in Microsoft Excel, and statistical analysis was performed on Stata-v14. The agreements and sensitivities of both the methods were compared. RESULTS: Forty patients out of 64 were found to have laminar resorption. A total of 48 laminae were studied, which had data on the presence or absence of resorption. The sensitivity and specificity of clinical detection of resorption were 87.5% (CI 68%-97%) and 37.5% (CI 8.5%-75.5%), respectively. Whereas, the sensitivity and specificity of CT scan were 81% (CI 61%-93%) and 50% (CI12%-88%), respectively. Both the methods have detected resorption in 21 out of 32 laminae having both the clinical and CT scan data. There is a fair agreement between the two techniques in the identification of thinned laminar sites. CONCLUSIONS: Clinical detection of laminar resorption in OOKP eyes is equally sensitive to the CT scanning. Resorption can be detected even in its early stages by clinical palpation in experienced hands. Frequent CT scanning is not indicated to detect laminar resorption. Both methods complement each other. Thinned laminar segments should be compared and correlated with both the methods for full evaluation of resorption.

Patch graft using collagen matrix (Ologen) for glaucoma drainage device exposure in a patient with Boston Keratoprosthesis type 1.

PURPOSE: To report the first successfully treated case of recurrent tube exposure in a patient with the Boston Keratoprosthesis type 1 with a collagen matrix patch graft (Ologen). OBSERVATIONS: A 50 year-old female with a Boston Keratoprosthesis type 1 and a history of Axenfeld-Reiger syndrome presents to our department with recurrent glaucoma drainage device exposure in her left eye. After failed spontaneous closure with topical antibiotics and lubricants, she undergoes tube exposure repair using an Ologen patch graft. Surgery was successful and the patient did not have any recurrence up to last follow-up two years post-operatively. CONCLUSION: Collagen matrix patch graft seems to be advantageous in treating glaucoma tube exposure in the Boston KPro eye, which is often a more challenging entity to treat. IMPORTANCE: Collagen matrix patch graft could be considered as a primary patch graft in treating tube exposure in eyes with the Boston KPro.

Surgical Management of Bilateral Limbal Stem Cell Deficiency.

Limbal stem cell deficiency (LSCD) is now established as a distinct entity with a spectrum of clinical manifestations. Bilateral LSCD presents a unique set of challenges to the clinician dealing with ocular surface disease, due to the underlying causes, clinical presentation, and adnexal status, as well as lack of a source of autologous limbal stem cells. Various surgical modalities have been described to achieve visual rehabilitation in patients with bilateral LSCD. These can primarily be divided into cell-based therapies and implantation of keratoprostheses. In this review, the surgical options for management of bilateral LSCD, including autologous and allogeneic cell-based therapies and different types of keratoprostheses are described and classified. The indications, prerequisites, technique, results and complications of each modality are discussed. Based on the status of the ocular surface, an algorithm for choosing appropriate surgical management for vision restoration in bilateral LSCD has been proposed.