KPro Implantation Research Articles

Fungal Infections After Boston Type 1 Keratoprosthesis Implantation: Literature Review and In Vitro Antifungal Activity of Hypochlorous Acid.

To review the current literature describing cases of fungal keratitis and endophthalmitis after Boston keratoprosthesis (KPro) implantation and to characterize the antifungal activity of 0.01% hypochlorous acid against medically relevant fungi. A literature review of fungal keratitis or endophthalmitis in KPro patients from January 2001 to April 2015, and an in vitro time kill assay characterizing the fungicidal activity of 0.01% hypochlorous acid against fungi causing ocular infections. Fifteen publications, predominantly retrospective case series, were identified. Infection rates after KPro implantation ranged from 0.009 to 0.02 fungal infections per patient-year of follow-up. The largest single-surgeon series reported an incidence of 2.4% for fungal endophthalmitis during a 10-year period. Causative organisms included both yeasts and molds. Outcomes were favorable if infections were caught early and treated appropriately; less favorable outcomes were reported in developing countries where fungal species are endemic and resources are limited. 0.01% hypochlorous acid is rapidly fungicidal, reducing the number of viable yeast cells or mold conidia by at least 99.99% within 60 seconds. The antifungal activity extended to all molds (Acremonium kiliense, Aspergillus flavus, Aspergillus fumigatus, Fusarium solani, and Mucor indicus) and yeast species (Candida albicans and Candida parapsilosis) tested. Fungal infections remain a lifelong concern in patients after KPro implantation. There is a growing need for a standard antifungal prophylaxis regimen, especially in the developing world. The rapid broad-spectrum in vitro fungicidal activity of 0.01% hypochlorous acid against all fungi tested makes it an attractive candidate as an antifungal prophylaxis in KPro patients.

Boston Type 1 Keratoprosthesis versus Repeat Donor Keratoplasty for Corneal Graft Failure: A Systematic Review and Meta-analysis

To compare repeat penetrating keratoplasty (PK) with Boston type I keratoprosthesis (KPro) implantation for full-thickness donor corneal graft failure. Previous donor graft failure is a common indication for both PK and KPro implantation. Selection of the surgical procedure is entirely dependent on the surgeon because there are no studies available for guidance. Therefore, a systematic review was undertaken to examine vision, device retention, graft clarity, and postoperative glaucoma and infection outcomes after repeat PK versus KPro implantation. Articles with data regarding repeat PK published between 1990 and 2014 were identified in PubMed, EMBASE, the Latin American and Caribbean Health Sciences Literature Database, and the Cochrane Central Register of Controlled Trials and were reviewed. Results were compared with a retrospective review of consecutive, nonrandomized, longitudinal case series of KPro implantations performed at 5 tertiary care centers in the United States. Visual acuity at 2 years was the primary outcome measure. The proportion of clear grafts in the repeat PK group, device retention in the KPro group, and the development of postoperative glaucoma and infection were secondary outcome measures. The search strategy identified 17 128 articles in the PK analysis. After screening, 26 studies (21 case series and 5 cohort studies) were included in the review. Pooled analysis of the 26 unique studies demonstrated a 42% (95% confidence interval [CI], 30%-56%) likelihood of maintaining 20/200 or better at 2 years after repeat PK, compared with an 80% (95% CI, 68%-88%) probability with KPro implantation. The probability of maintaining a clear graft at 5 years was 47% (95% CI, 40%-54%) after repeat PK, whereas the probability of retention of the KPro at 5 years was 75% (95% CI, 64%-84%). The rate of progression of glaucoma at 3 years was 25% (95% CI, 10%-44%) after repeat PK and 30% in the KPro cohort. These results demonstrate favorable outcomes of KPro surgery for donor corneal graft failure with a greater likelihood of maintaining visual improvement without higher risk of postoperative glaucoma compared with repeat donor PK.

Outcomes of Repeat Boston Type 1 Keratoprosthesis Implantation

To describe the outcomes and prognostic characteristics of patients who had a repeat Boston type 1 keratoprosthesis (KPro) implantation. Retrospective case series. setting: Data regarding preoperative clinical and demographic characteristics and postoperative course during initial and repeat KPro placement were collected at multiple centers across the country. Forty-eight eyes underwent explantation of KPro owing to complications between September 2003 and August 2014 at 5 participating tertiary eye care centers in the United States. Of those, 36 eyes that received a subsequent replacement device were included. Visual acuity (VA) outcomes and postoperative complications. Ocular surface disease was significantly more common in eyes that required a device explantation, compared to those that retained the device (P < .001). Sixty-seven percent of eyes (24/36) achieved VA ≥ 20/200 vision after the repeat KPro. The probability of these 24 eyes maintaining VA ≥ 20/200 after the repeat KPro was 87% at 1 year and 75% at 2 years. Predictors of the ability to maintain vision ≥ 20/200 following surgery were a better last-recorded vision before explantation (P = .0002) and better vision immediately after repeat KPro (P < .001). Ocular surface disease and its complications were associated with more frequent device removal. In these patients, repeat KPro resulted in restoration of vision. A reasonable visual acuity prior to device removal was associated with favorable long-term postoperative visual acuity and retention.

Analysis of clinic results and complication associated with Boston I keratoprosthesis

This study was to evaluate clinical results and complications associated with the Boston type I keratoprosthesis implanted into complex corneal opacity. Retrospective study. Sixty-one eyes (57 cases) received Boston type I KPro implantation between May 2011 and January 2013 in the Chinese PLA General Hospital, and were followed for at least 2 months (range, 2 to 27 months, mean 19 months). Indications for keratoprosthesis included thermal injury (n = 17), chemical injury (n = 19), herpetic keratitis (n = 8), blast injury (n = 6), keratitis (n = 8), antoimmune diseases (n = 2) and corneal endothelial decompensation (n = 9). Kpro implantation in accordance with the Massachusetts Eye Center standardized surgical approach, and routine lens removal meantime. Clinical complications and postoperative treatments were recorded. Preoperative visual acuity were light perception to the counting figure in all the patients. Forty-seven eyes (77%) had better best correct visual acurity than counting figure and 18 eyes (30%) had BCVA better than 0.3 after implantation. Postoperative complications indluded carrier corneal melting (10 cases), retroprothesis membrane (6 cases), glaucoma (12 cases), retinal detachment (2 cases), choroidal detachment (1 case), endophthalmitis (2 cases). Complications take symptomatic treatment, in addition to glaucoma patients and two cases of endophthalmitis patients (Evisceration), all patients can maintain the original best corrected visual acuity. Timely examination of the KPro and replacement with donor cornea may prevent a poor outcome. Close follow-up is necessary after KPro-implantation.

The Boston Keratoprosthesis type 1 as primary penetrating corneal procedure

Background/aimsPenetrating keratoplasty (PK) has a poor prognosis in certain corneal eye diseases. The safety and efficacy of Boston type 1 Keratoprosthesis (KPro) surgery as a primary penetrating corneal surgery were...

A new epidescemetic keratoprosthesis: pilot investigation and proof of concept of a new alternative solution for corneal blindness

PurposeTo report the outcomes of a new model of epidescemetic keratoprosthesis (Kpro) implanted without total corneal trephination.MethodsPatients were considered for implantation with the new Kpro model (KeraKlear) if they were...

Vision-related quality-of-life assessment using NEI VFQ-25 in patients after Boston keratoprosthesis implantation.

The aim of this study was to determine the impact of Boston keratoprosthesis (KPro) implantation on patient-reported visual function using the National Eye Institute Visual Function Questionnaire 25 (NEI VFQ-25). This is a prospective study of patients undergoing implantation of Boston KPro. The NEI VFQ-25 was used to assess vision-related quality of life preoperatively and postoperatively at 3 and 6 months and yearly thereafter. Baseline scores were compared with postoperative scores using paired t test. Stratified analysis was performed to compare results by visual acuity of the contralateral eye. Twenty-four patients were included. Mean baseline NEI VFQ-25 overall score was 44.6. At the first follow-up time point, mean overall score was 70.0, representing a statistically significant change from baseline (P < 0.001). Breakdown of subcategories within VFQ-25 showed significant improvement in general vision, near and distance activities, social functioning, mental health, role difficulties, dependency, color vision, and peripheral vision (P < 0.05). This improvement was also observed when comparing baseline scores with postoperative scores at average follow-up of 16 months. Although a greater change in scores was observed in patients who had poor vision in the contralateral eye, patients with vision better than 20/200 in the nonsurgical eye showed statistically significant improvement in overall scores and subscale scores compared with baseline. The quality of life of patients who underwent KPro significantly improved postoperatively compared with their preoperative status. These results did not change when stratifying by visual acuity of the contralateral eye.

Predictors of Visual Outcomes Following Boston Type 1 Keratoprosthesis Implantation

To identify predictors of visual outcomes following Boston type 1 Keratoprosthesis (KPro) implantation. Retrospective chart review. Data regarding preoperative clinical and demographic characteristics and postoperative course were collected. Fifty-nine eyes of 59 adult patients who underwent KPro implantation between January 2006 and March 2012 at a single tertiary care center. Preoperative factors associated with all-cause and glaucoma-related loss of visual acuity from the best postoperative visual acuity noted. Fifty-two of 59 eyes (88%) achieved improved vision post implantation, with 7 eyes failing to gain vision as a result of pre-existing glaucoma (n= 4) or retino-choroidal disease (n= 3). Twenty-one eyes (21/52, 40%) maintained their best-ever visual acuity at last visit (mean follow-up period was 37.8months). The likelihood of maintaining best-ever vision was 71% at 1 year, 59% at 2 years, and 48% at 3 years. Primary KPro implantation was associated with a higher likelihood of losing best-ever vision as compared to KPro implantation as a repeat corneal procedure (hazard ratio [HR]= 3.06; P= 006). The main reasons for postimplantation vision loss was glaucoma (12/31, 39%), and the risk of glaucomatous visual acuity loss was 15% at 2 years and 27% at 3 years. Prior trabeculectomy was associated with a higher rate of vision loss from glaucoma (HR= 3.25, P= .04). Glaucoma is the primary reason for loss of visual acuity after KPro implantation. Conditions necessitating primary KPro surgery are associated with more frequent all-cause vision loss. Prospective trials are necessary to better determine which clinical features best predict KPro success.

Anterior Segment Optical Coherence Tomography in the Long-Term Follow-up and Detection of Glaucoma in Boston Type I Keratoprosthesis

To evaluate the role of anterior segment (AS) optical coherence tomography (OCT) as a standardized method of imaging Boston type I keratoprosthesis (KPro) after surgery, particularly in the visualization of iris and angle structures. Prospective case series. Twenty patients who underwent KPro implantation in 1 eye. Patients underwent AS OCT imaging before surgery. After KPro implantation, patients were imaged using the AS single, dual, and quad scans to obtain transverse images of the eye every 15° over 360°. High-resolution, corneal quad, and anterior chamber scans were also obtained. This imaging protocol allowed juxtaposition and comparison of the same imaging coordinates obtained before surgery and 3, 6, and 12 months after surgery. Postoperative visual acuity (VA), glaucoma progression on clinical examination and formal visual field testing, and anatomic angle changes on AS OCT defined by angle closure, peripheral anterior synechiae (PAS), iris-KPro backplate touch, and graft-host interface changes over time. Mean follow-up was 18.8±3.2 months. The average preoperative VA was 1.9±0.5 logarithm of the minimum angle of resolution. After surgery, VA improved to 1.0±0.9 at last follow-up (P= 0.002). Fourteen of 20 patients had glaucoma before surgery. After surgery, 5 of these patients deteriorated clinically and 1 de novo diagnosis of glaucoma was made. On OCT, the average total degrees of angle closure for all patients increased from 158.5±158.9° before surgery to 205.4±154.0° after surgery (P= 0.04). The number of eyes with 360° of PAS increased from 6 of 20 before surgery to 9 of 20 after surgery. Iris-backplate touch was demonstrated in 5 of 20 patients, with an average area of involvement of 24.2±36.2°. Overall, of the 12 of 20 patients with clear signs of anatomic angle narrowing and synechiae progression on imaging, 3 had glaucoma deterioration detected by clinical examination. In the other 9 patients, angle changes on OCT were not accompanied by any detectable clinical signs of glaucomatous deterioration. Anterior segment OCT can be used to observe anatomic changes after KPro implantation that cannot be detected otherwise. We were unable to demonstrate a correlation between anatomic features and clinical progression.

Endophthalmitis in Boston keratoprosthesis: case series and review of literature.

To report the clinical and microbiological characteristics of infectious endophthalmitis after Boston type I keratoprosthesis (B-K-Pro) implantation. Retrospective analysis of 136 eyes that received a B-K-Pro type 1 between 1999 and 2012 was performed. Five eyes with a diagnosis of exogenous endophthalmitis after B-K-pro type 1 were identified and information about demographic data, indication for K-Pro, post-operative bandage contact lens use, post-operative prophylactic antibiotic use, timing and clinical presentation of endophthalmitis, gram stain and culture results of intraocular fluid and preoperative and post-operative visual acuity were collected. The incidence of endophthalmitis was 3.67% (5 of 136 eyes) and average time to develop endophthalmitis was 5.62 months (range 2 days to 8 months). Mean patient age was 31.4 years (5 to 65 years). The surgical indications included corneal injury due to chemical burns (n = 2), multiple failed grafts secondary to microbial keratitis (n = 2) and congenital glaucoma with congenital herpetic keratitis (n = 1). Post-Boston K-Pro, the visual acuity ranged from light perception (LP) to 20/50. K-pro was explanted in 4 patients. There was bacterial and fungal growth in two patients each and one vitreous did not grow anything. All the eyes were phthisical at last visit. Infectious endophthalmitis after K-Pro implantation in our study had a higher incidence, early onset and extremely poor visual outcome compared with post-cataract surgery endophthalmitis, as reported in literature. Not only bacterial but also fungal infections are an important etiology for infectious endophthalmitis in these cases.

Long-term Outcomes of Boston Type 1 Keratoprosthesis Implantation: A Retrospective Multicenter Cohort

To study the long-term outcomes of Boston type 1 keratoprosthesis (KPro) surgery. Retrospective, multicenter case series. A total of 158 eyes of 150 patients underwent KPro implantation at 5 participating tertiary centers in the United States between January 2003 and December 2006. Of those, 139 eyes of 133 patients were included in the analyses. The medical records of consecutive adult patients who received KPro surgery were reviewed. All patients with at least 1 postoperative visit were retained in the outcomes analyses. In eyes in which a repeat KPro procedure was performed, only the outcomes of the initial surgery were analyzed. Visual acuity (VA) outcomes, postoperative complications, and device retention. The mean follow-up was 46.7 ± 26 months with all but 4 eyes having at least 6 months of follow-up. Preoperatively, only 10.8% of the eyes had VA of ≥ 20/200. Postoperatively, the VA in 70% of eyes improved to ≥ 20/200. The probability of maintaining VA of ≥ 20/200 at 7 years was 50%. The device retention rate was estimated at 67% at 7 years. The 7-year cumulative incidence of complications was 49.7% for retroprosthetic membrane formation, 21.6% for glaucoma surgery, 18.6% for retinal detachment, and 15.5% for endophthalmitis. Although the risk for complications with longer follow-up seemed to increase, this large multicenter cohort demonstrates favorable outcomes with KPro, with a large number of patients achieving and retaining useful vision over a 7-year period.

Outcomes Following Boston Type 1 Keratoprosthesis Implantation in Aniridia Patients at the University of Montreal

To describe outcomes after Boston Type 1 Keratoprosthesis (KPro) surgery in aniridic eyes. Retrospective, interventional case series. University-based tertiary care institution. Twenty-six aniridic eyes of 19 patients who underwent KPro implantation by a single experienced surgeon (M.H.-D.) between October 27, 2008 and January 16, 2012. Preoperative and postoperative best-corrected visual acuity (BCVA), intraoperative and postoperative complications, and keratoprosthesis retention. Mean age was 56 years (range, 28-72); 10 patients were male. Seven patients had bilateral procedures. No intraoperative complications were encountered. Preoperatively, BCVA was 20/300 or worse in all eyes. After a mean follow-up time of 28.7±13.5 months (range 4-50), the most recent BCVA was 20/200 or better in 14 eyes. Visual potential was limited by preexisting terminal glaucoma (n=2), phthisis after retinal detachment (n=4), and suprachoroidal hemorrhage (n=2). Other postoperative complications included retroprosthetic membrane formation (n=15), infectious keratitis (n=1), extrusion (n=2), and corneal melt (n=4). Uncomplicated vitritis was reported in 6 eyes. No endophthalmitis occurred in this series. Most eyes have glaucoma and are on medical treatment. The overall retention rate of the initial prosthesis was 77%. The prognosis in aniridic patients after KPro is variable. Meticulous follow-up and a subspecialty team approach are of utmost importance.

A novel murine model for keratoprosthesis.

To establish a murine model for keratoprosthesis. A miniature keratoprosthesis (m-KPro) device was created consisting of a poly[methyl methacrylate] front part and a titanium back plate, designed after the Boston KPro, which is in widespread clinical use. BALB/c mice were used and a 2 mm in diameter donor cornea was punched out. After 2-mm trepanation of the syngeneic recipient cornea, extracapsular crystalline lens extraction was performed. The m-KPro was assembled onto the cornea button in a similar manner to human KPro implantation. The cornea-device complex was secured to the recipient bed with eight interrupted 11-0 sutures. All mice (n = 10) were followed up for 8 weeks postoperatively. All m-KPros were successfully implanted and retained in all 10 animals. There were no critical complications such as endophthalmitis, corneal melting, device extrusions, leakage, extensive inflammation, or weight loss in the animals. We observed mild to moderate donor and host corneal neovascularization in all cases throughout the follow-up period. We have established a novel murine model of KPro implantation that we anticipate will serve as a good experimental system for evaluating host responses after KPro surgery.

Scleral Intraocular Pressure Measurement in Cadaver Eyes Pre- and Postkeratoprosthesis Implantation

We correlated scleral IOP to assigned IOP using pneumatonometry in cadaver eyes before and after Boston type I keratoprosthesis (KPro) implantation. Corneal IOP and scleral IOP at the superonasal, superotemporal, inferotemporal, and inferonasal quadrants were measured using pneumatonometry in six cadaver eyes cannulated with an infusion line with assigned IOP held at 20, 30, 40, and 50 mm Hg. Measurements of scleral IOP at the same location were repeated after a KPro was implanted. Correlations between scleral IOP and assigned IOP were analyzed for the entire group of eyes, and for each individual eye before and after KPro. One eye was tested by another masked grader for interobserver variability. Scleral IOP measured higher than corneal IOP by a mean of 13.2 mm Hg. For group analysis, pre-KPro scleral IOP had a positive and linear correlation with assigned IOP in all quadrants (P < 0.00001), and this correlation was preserved after KPro implantation (P < 0.00001). There was strong interobserver agreement in all measurement sites (P < 0.001). In analyses of individual eyes, scleral IOP measured at the inferotemporal quadrant confirmed the strong linear association between scleral IOP and assigned IOP before and after KPro for all study eyes. A Bland-Altman plot showed that the difference in scleral IOP between pre-KPro and post-KPro eyes fell mostly within ± 5 mm Hg. Scleral IOP measured by pneumatonometry may be used to estimate IOP in cadaver eyes with and without keratoprosthesis. This may be a potential modality for assessing IOP for patients with corneal pathology or keratoprosthesis.

Gamma-Irradiated Corneas as Carriers for the Boston Type 1 Keratoprosthesis

The Boston keratoprosthesis (KPro) is the most commonly used KPro worldwide. There are limited data on the outcomes when irradiated corneas are used as KPro carriers. We report a retrospective analysis of corneal transplantations performed in a regular surgical mission setting in Beirut, Lebanon, using the Boston KPro type 1 and gamma-irradiated carrier corneas, and we describe visual outcomes, complications, and retention percentage. We conducted a retrospective analysis of 17 consecutive eyes from 16 patients who underwent Boston KPro type 1 implantation at the Beirut Eye Specialist Hospital between December 2010 and July 2012. Patient medical records were reviewed for preoperative, intraoperative, and postoperative details. Postoperatively, 9 (52.9%), 5 (29.4%), and 2 (11.7%) eyes had a corrected visual acuity of 20/400 or better, 20/100 or better, and 20/40 or better, respectively, at the most recent follow-up visit. A total of 16 eyes (94.1%) improved in corrected visual acuity over the course of follow-up. Overall, 13 eyes (76.4%) developed at least 1 complication after surgery. Retroprosthetic membrane formation was the most common complication, occurring in 10 eyes (58.8%). Neither infectious keratitis nor corneal stromal necrosis was noted during the follow-up period. The retention percentage was 94.1%. The visual acuity outcomes, incidence of complications, and retention percentage of the KPro using gamma-irradiated carrier corneas are comparable with the outcomes of KPro implantation reported in the literature using fresh grafts as carriers. KPro with irradiated corneal carrier grafts seems to be an effective option to increase the supply of transplantation suitable corneas in remote areas, where fresh corneal grafts may be scarce.

Influence of Primary Diagnosis and Complications on Visual Outcome in Patients Receiving a Boston Type 1 Keratoprosthesis

Purpose: To analyse how primary diagnosis and complications affect the evolution of post-operative visual acuity (VA). Methods: We performed retrospective chart analysis on 59 eyes in 57 patients with various diagnoses, most of which were non-standard indications for Boston type 1 keratoprosthesis (Kpro) implantation. The follow-up period was at least 3 months. Patients were classified based on the evolution of post-operative VA: group A demonstrated stable VA improvement, group B lost VA improvement and group C no significant VA improvement. Results: We assigned 46% of our cases to group A with stable VA improvement, 32% to group B with lost VA improvement, and 22% to group C with no VA improvement. The number of graft failures before Kpro implantation did not influence VA outcome. Except for the relatively good VA outcome in chemical burn and radiation injury patients, there seems to be no association between primary diagnosis and positive or negative VA outcome. Only 9% of patients with posterior segment complications and 20% with infections and associated pathologies were assigned to group A. Conclusion: Most cases (78%) showed improvement in VA after Boston type 1 Kpro (groups A and B). Posterior segment complications and infections mostly resulted in persistent loss of vision. These complications should be prevented and carefully treated.

Evaluation of Microbial Flora in Eyes With a Boston Type 1 Keratoprosthesis

To evaluate the microbial flora of eyes with a Boston Keratoprosthesis (K-Pro). A prospective study was performed for 17 eyes of 15 patients who underwent a K-Pro implantation between September 2005 and June 2011. Preoperative diagnoses included failed corneal grafts, limbal stem cell deficiency, chemical burns, and Stevens-Johnson Syndrome. The patients used topical antibiotics after their surgery including a fluoroquinolone, polymyxin-trimethoprim, vancomycin, or a combination of the 3. The conjunctiva in the study eye was swabbed and cultured. A separate culture was taken of the contralateral eye as well. If available, the bandage contact lens was removed, and half of it was placed in thioglycolate broth, and half in 5 mL of a sterile balanced salt solution. The contact lens in the balanced salt solution was sonicated using a QSonica Q125 sonicator (Newtown, CT) for 1 minute, at an amplitude of 20%. Ten microliters of fluid was subsequently cultured. Of the patients who underwent the K-Pro surgery during that time period, 15 patients with 17 eyes were able to participate in the data collection. Nine of the 17 eyes implanted with the K-Pro (53%) had positive cultures. Two of the 13 (15%) of the control swabs exhibited bacterial growth. Eight percent (1/12) of the sonicated lenses were positive on culture, whereas 4/12 (33%) of the lenses placed in thioglycolate broth were positive for organisms. Despite being on antibiotics, eyes implanted with the K-Pro were more likely to have a positive conjunctival culture in our cohort as compared with that of fellow eyes.

Anatomical survival and visual prognosis of Boston type I keratoprosthesis in challenging cases

To describe the outcome of patients with Boston type 1 keratoprosthesis, with regard to anatomical and visual success. Retrospective case series of patients who underwent Boston type I keratoprosthesis surgery at the Centro de Oftalmología Barraquer in Barcelona and at the University Eye Clinic in Salzburg between May 2006 and December 2011. Sixty-seven eyes were included. Anatomical success, visual acuity, and complication rate were evaluated and correlated with the initial diagnosis. The mean age of patients was 54years; 62% were male and 38% were female. Eleven patients underwent Type I Boston Kpro implantation as a primary procedure, while the other 52 patients had previous graft failure. The most frequent diagnoses were autoimmune diseases (16 eyes), severe chemical or thermal burn (12 eyes), leukoma post-infectious keratitis (seven eyes) and bullous keratopathy (six eyes). The mean follow-up time was 26months. Retention of the prosthesis was achieved in 95% at 1year and 78% at 4.5years. Two eyes suffered extrusion of the KPro, six underwent successful exchange of the prosthesis either due to infection, necrosis or extrusion, three KPro's had to be explantated, and two eyes ended up in enucleation due to panophthalmitis. The outcome of the autoimmune cases was similar to the group with "other diagnoses" and better than those with chemical/thermal burn. The most frequent complication was development of a retroprosthetic membrane in 21 eyes (34%). Visual acuity (LogMAR) in the chemical/thermal burn group was 2.30 preoperatively, 0.69 at 1year, 0.52 at 2years and 0.39 at 3years; in the autoimmune group visual acuity was 2.3 preoperatively, 0.65 at 1year, 0.15 at 2years, and 1.5 at 3years. Boston type 1 keratoprosthesis is a viable option for patients with repeated graft failure, even for those with challenging diagnoses such as ocular burns and autoimmune syndromes.

Infectious Keratitis After Boston Type 1 Keratoprosthesis Implantation

To determine the incidence, clinical features, and outcomes of infectious keratitis after Boston type 1 keratoprosthesis (Kpro) implantation. Ten cases of infectious keratitis were identified in a retrospective chart review of 105 patients (126 eyes) who received Kpro between November 2004 and November 2010 at the Cincinnati Eye Institute and were followed for at least 1 month (range, 1-66 months; mean, 25 months). The incidence was 7.9%. Patient diagnoses included 4 chemical injuries, 3 Stevens-Johnson syndrome, 2 ocular cicatricial pemphigoid, and 1 congenital aniridia. Kpro implantation was indicated in 2 eyes for a failed ocular surface and in 8 for penetrating keratoplasty failure. Four patients were contact lens intolerant or noncompliant. All were on topical vancomycin and moxifloxacin for prophylaxis and 2 were on topical amphotericin for prophylaxis. Three infiltrates were culture negative, 5 were fungal (3 Candida, 1 Fusarium, 1 Dactylaria constricta), and 2 were bacterial (Rhodococcus equi and Gram-negative cocci). All patients were managed with topical agents and 4 were given an oral antifungal agent. Four patients had Kpro removal with therapeutic penetrating keratoplasty and 1 had Kpro replacement. At final follow-up, only 2 patients retained their preinfection best vision. Risk factors for infectious keratitis included a diagnosis of cicatrizing conjunctivitis (Stevens-Johnson syndrome, ocular cicatricial pemphigoid, or chemical injury) and a history of persistent epithelial defect (P = 0.0003 and 0.0142, respectively). Contact lens wear, vancomycin use, and a history of systemic immunosuppression (or use at the time of infection) were not statistically significant risk factors. Infectious keratitis after Kpro can occur even when patients are on vancomycin and a fourth-generation fluoroquinolone for prophylaxis. Fungal organisms are a growing cause for concern, and we present the details of the first reported case of ocular D. constricta. The evolution of our management and prophylaxis strategy for fungal keratitis after Kpro implantation is also described.

Eyelid Procedures in Patients Who Have Undergone Boston Keratoprosthesis Surgery

Artificial corneas or keratoprostheses such as the Boston keratoprosthesis (KPro) are being used more frequently to provide a clear corneal window in patients with severe corneal disease. A significant percentage of patients who undergo Boston KPro implantation require subsequent eyelid surgery. However, few articles in peer-reviewed literature evaluate the indication and outcome of eyelid procedures after Boston KPro implantation. This study examines the frequency, nature, and outcomes of oculoplastic procedures in patients with Boston KPro implantation. A retrospective chart review was conducted of all KPro-1 procedures performed at the University of Illinois at Chicago between December 2006 and September 2010 and all KPro-1 and KPro-2 procedures performed at the University of Iowa between December 2008 and October 2010. One hundred and twenty eyes underwent Boston KPro-1 procedures, and 2 eyes underwent Boston KPro-2 procedures. Twenty-one (17.2%) of the 122 eyes required subsequent eyelid alterations. Chemical burn was the most common preoperative corneal diagnosis (8 of 21; 38.1%). A variety of oculoplastic procedures were performed; the most common procedure was a permanent lateral tarsorrhaphy. Seventeen (81.0%) of 21 KPro eyes that underwent oculoplastic procedures maintained the KPro at an average of 12.4 months of follow up. A significant number of patients with Boston KPros require subsequent eyelid surgery. With limited existing literature and increasing popularity for using Boston KPros to treat severe corneal disease, it is essential for oculoplastic and corneal surgeons to understand the need for eyelid alterations in these patients and the surgical intricacies surrounding these cases.