Graft-host Junction Research Articles

Impact of COVID-19 related national lockdown on care of corneal transplantation patients at a tertiary eye care centre in India.

Purpose:To study impact of COVID-19 related national lockdown on care of corneal transplantation patients at a tertiary eye centre in Andhra Pradesh state of South India.Methods:Cross-sectional questionnaire-based study conducted at tertiary eye care centre in Andhra Pradesh state of South India, included 109 patients who underwent keratoplasty(full thickness or partial thickness) at our centre and who came for follow-up visit after lockdown. Factors such as type, indication, number of keratoplasties in the operated eye, and unusual clinical outcomes identified during visit after the lockdown, were studied. Uncorrected visual acuity, best corrected visual acuity, clarity of graft, graft-host junction apposition, intactness of sutures, intraocular pressure and disc status were compared on visits made before and after lockdown.Results:During lockdown, 77.1% patients were properly using medications that was significantly (P = 0.0003) lower than that of before the lockdown (90.8%). After the lockdown, 82.3% patients were using medications properly that was comparable (P = 0.11) to that of during the lockdown (77.1%). The proportion of eyes with clear grafts and intact sutures decreased significantly after lockdown. The unusual outcomes observed after the lockdown were graft failure (36.7%), graft edema (11%), graft infiltrate(5.5%), phthysis bulbi (1.85%) and edematous graft cleared in eyes 3.7% eyes.Conclusion:We noted significant drop in usage of medications from 91% before lockdown to 77% during lockdown and maintained at 83% after lockdown. Edematous grafts increased from 41% before lockdown to 54% after the lockdown. Intactness of sutures decreased from 82% before lockdown to 69% after lockdown.

Megaprosthesis Versus Allograft Prosthesis Composite for the Management of Massive Skeletal Defects: A Meta-Analysis of Comparative Studies.

Megaprosthesis and Allograft Prosthesis Composite (APC) are the established treatment modalities for massive skeletal defects. There are a handful of studies comparing the use of megaprosthesis and APC in the management of substantial bone loss and it has always been a topic of debate regarding the superiority of one modality over the other. Therefore, we aim to compare the functional outcome and implant survivorship of each modality including complications, revision rates, amputation rate and mortality. The Allograft Prosthesis Composite (APC) constitutes a skeletal allograft implanted with a revision type prosthesis in it. The biological environment provided by the allograft allows attachment of the muscles and tendons imparting better stability and function. However, the literature is not kind enough with APC due to associated risk of infection, disease transmission and nonunion at the graft-host junction. The megaprosthesis (MP) on the other hand is a nonbiologic modality with better survivorship but subservient functional outcome. Infection has been a major issue in both the modalities. Advancement in metallurgy using silver coated megaprosthesis also failed to provide strong evidence in preventing infection. The functional outcome is better with APC in both the upper and lower limbs. However, the survivorship is better with megaprosthesis, especially in the upper limb when revision rates were compared between the two modalities. Deep infection and mechanical complications were significantly higher in the APC group. There was no significant difference between the two groups in terms of amputation rate, mortality, and local recurrence. 2a.

Benefit of collagen cross linking of the donor corneal button and the graft host junction during therapeutic penetrating keratoplasty - A pilot study

Collagen crosslinking (CXL), used as a treatment modality in infectious keratitis, can be further studied for the prevention of recurrent infection in cases undergoing therapeutic penetrating keratoplasty (TPK). To study the role of collagen crosslinking of the donor corneal tissue and the graft host junction during TPK in preventing recurrence of infection. This was a prospective, clinical, interventional pilot case study done from May 2017 to July 2018. Fifteen cases and 15 controls who had infectious keratitis and needed TPK were included. Pediatric patients, one eyed patients, perforated ulcers and those with any other significant co-morbidity were excluded. In patients who were enrolled as cases, the donor corneal graft and the graft host junction were subjected to CXL using modified Dresden protocol just after the TPK. TPK was done as per standard protocol. The patients were followed up for at least four months duration and the recurrences in both the groups were recorded. The Odds Ratio of the cases not developing a recurrent infection vis-a-vis the controls has been calculated along with the Confidence Interval using the SPSS Statistics software. Recurrence of infection was found in one case and in four controls within one month of TPK. CXL done on donor corneal tissue and the graft host junction intra operatively, has a role in reducing recurrence of infection after TPK.

Suturing large therapeutic corneal grafts based on donor size: A simplified technique for the novice corneal surgeon.

We describe a simple technique for achieving radial and equally spaced sutures by novice corneal surgeon in cases of large penetrating keratoplasties. A simple mathematical equation was derived for precise calculation of spacing between interrupted sutures in large grafts (n = 50). The ubiquitous and easily available Castroviejo calipers were used to mark the donor cornea according to the derived formula. Interrupted sutures were passed over the pre-marked points and tied. Radiality was assessed in the post-operative period. A total of 50 eyes undergoing therapeutic keratoplasty with graft size between 9 and 12 mm were enrolled. Equally spaced and radially aligned sutures were achieved in all cases postoperatively with watertight apposition of the graft host junction using our simple technique. The Castroviejo caliper can be effectively used for equidistant spacing of interrupted sutures in large therapeutic grafts by a novice surgeon thereby simplifying the procedure and reducing the surgical time.

Scleral Lens-Induced Corneal Edema after Penetrating Keratoplasty.

Modern highly oxygen-permeable nonfenestrated scleral lenses induce approximately 1 to 2% corneal edema after short periods of lens wear in healthy individuals. This study investigated the magnitude and regional variation in scleral lens-induced central corneal edema after penetrating keratoplasty. The purpose of this study was to examine the magnitude and regional variation in corneal edema after a short period of scleral lens wear in post-penetrating keratoplasty eyes and a control group of eyes with healthy corneas. Nine post-penetrating keratoplasty eyes (nine participants; mean age, 32 years) were fitted with highly oxygen-permeable nonfenestrated scleral lenses (Dk 100 × 10 cm O2 (cm)/[(s) (cm) (mmHg)]). Central corneal thickness was measured using Scheimpflug imaging before lens insertion and immediately after lens removal (mean wearing time, 6.2 hours). Corneal edema was quantified across the central 6 mm and compared with data obtained from a historical control group of healthy eyes using a similar experimental paradigm. Post-penetrating keratoplasty eyes exhibited significant corneal edema after lens wear (2.99% [95% confidence interval, 1.13 to 4.85%]) averaged across the central 6 mm (P = .006) and regional variations in edema (P < .001) (greater swelling toward the graft-host junction inferiorly). Compared with healthy eyes, post-penetrating keratoplasty eyes displayed a greater magnitude of corneal edema (by ~3×) and greater variability in the corneal response (by ~2.5×). Scleral lens-induced central corneal edema is greater in post-penetrating keratoplasty eyes and varies regionally compared with healthy corneas after short-term wear. Lens design and fitting factors contributing to hypoxic and mechanical corneal stress should be carefully considered for all post-penetrating keratoplasty scleral lens fits to minimize potential graft rejection or failure in the longer-term.

Long term evaluation of pterygium excision with conjunctival autografting using autologous blood

To evaluate the long term outcome of pterygium excision with conjunctival autografting (CAG) using economically viable autologous blood. This is a retrospective analysis of total 40 patients who underwent Pterygium excision with CAG using autologous blood as per our inclusion and exclusion criterion. After pterygium excision by avulsion method, we put the 1mm oversized CAG using autologous blood oozing on bare sclera and margins were tucked. Gentle massage for 10 minutes was given. The patients were followed for 48 months to measure the outcome. Our study shows CAG with autologous blood is very effective with zero percent recurrence and retraction of graft. Only in 1 case (2.5%) we have identified gap in graft-host junction as long term complications. This also does not required any intervention as gap was 1mm.Our study shows long term safety, success of economically viable CAG with autologous blood following pterygium excision.

Traumatic wound dehiscence after penetrating keratoplasty: Clinical features and outcome in 53 cases in Yemen.

AIMS:Penetrating keratoplasty (PKP) carries the risk of developing wound dehiscence, which can lead to vision loss. The main aim of this study is to analyze the management and outcome of surgery for traumatic wound dehiscence occurring in patients who had PKP.SUBJECTS AND METHODS:This retrospective study included post-PKP patients who sustained traumatic wound dehiscence at the Cornea Unit in Yemen Magrabi Eye Hospital between 2008 and 2016. Fifty-three eyes with a history of wound dehiscence were treated with primary wound closure. Patient files were reviewed for type and time of injury, distance visual acuity (VA), and outcome.RESULTS:Ruptured globe with dehiscence of wound occurred on average 2.4 years (3 months to 13 years) after PKP. The mean age at wound dehiscence was 22.27 years and males accounted for 77.4% (41). All patients were managed with primary closure of the wound. Lensectomy of traumatic or dislocated lens was the most frequent additional surgical procedure (14, 26.4%), followed by anterior vitrectomy (6, 11.3%). In the end, 43 (81.1%) grafts remained clear. In the last follow-up, 34 eyes (64.1%) had best-corrected VA of 20/200 or better and two eyes had no perception of light.CONCLUSION:Rupture globe and wound dehiscence occurs after PKP at the graft–host junction. Wound dehiscence is a lifelong risk after PKP and wound weakness persisted for a long period after PKP. Visual outcome and graft survival are generally poor after the injury, and the restoration of a satisfactory visual result is possible if treated early.

A peculiar case of corneal autograft in a patient with bilateral advanced glaucoma

The technique of autograft employs the use of a clear corneal graft from an otherwise blind eye that is transplanted to the fellow eye, which has a visual potential in the same patient. A patient with advanced glaucoma in both eyes presented to us with pseudophakic bullous keratopathy with Ahmed glaucoma valve in the right eye, and cataract and patent peripheral iridotomy with no perception of light in the left eye. The autograft and allograft corneas for bilateral penetrating keratoplasty (PK) were obtained from the contralateral eye and a cadaver eye, respectively. Central corneal button was used for PK. One year after the surgery, the graft host junction was well apposed with no vascularization, corneal surface was clear, sutures were intact, and best corrected visual acuity improved in right eye to 1 logMAR. Bilateral simultaneous PK with autograft in one eye and allograft in the other was done to decrease the chances of rejection.

A novel blunt dissection technique to treat modified deep anterior lamellar keratoplasty (DALK)-associated high astigmatism.

To describe a new surgical technique to correct a high astigmatism following modified deep anterior lamellar keratoplasty (DALK) and to evaluate the associated clinical outcomes. Retrospective interventional case series included eyes with high astigmatism following modified DALK performed between July 2012 and June 2016. The prevalence of keratometric astigmatism (KA) higher than 4.5 diopters (D) was evaluated after complete suture removal. Surgical correction was obtained by opening the surgical wound at the steeper meridian and carrying out a blunt dissection at the graft-host surface of contact under keratoscopic control. KA, Refractive astigmatism (RA), and best spectacle-corrected visual acuity (BSCVA) were measured preoperatively and at 1, 12, and 24 months postoperatively. Vector analysis of 1 year change in KA was performed. High astigmatism was found in 47 of 511 eyes (9.2%). KA (mean ± standard deviation [SD]) decreased from 7.67 ± 2.78 to 3.10 ± 1.37 D at 1 month after astigmatic correction (p < 0.001) with no subsequent significant change. Vector analysis of 1 year change in KA: surgically induced astigmatism was 5.30 ± 3.29 D and mean absolute angle of error was 6.97 ± 4.25°. BSCVA improved from 0.21 ± 0.20 logMAR preoperatively to 0.11 ± 0.13 logMAR (p < 0.001); RA decreased from 6.32 ± 2.56 to 2.61 ± 1.05 D (p < 0.001). No intra- or post-operative complications occurred. High astigmatism is present in <10% of cases after modified DALK and can be effectively managed by means of blunt relaxing dissection at the graft-host junction.

Peripheral Reconstructive Lamellar Keratoplasty for Late Ectasia After Penetrating Keratoplasty in Keratoconus Eyes.

To describe outcomes of customized peripheral anterior lamellar keratoplasty (PALK) for late ectasia of the donor-recipient junction after penetrating keratoplasty (PK) for keratoconus. This was a single-center, retrospective review of 33 eyes (28 patients) that developed ectasia restricted to the graft-host junction; 17 eyes underwent PALK using lamellar resections of 8- to 11-mm width starting at the external margin of the previous PK and suturing a same-size donor graft (annular or segmental). Five eyes were excluded from analysis because of postoperative complications unrelated to the technique. The average time between PK and diagnosis of secondary ectasia was 28 years (range 9-49 years). Slit-lamp examination showed localized thinning and elongation of the scar at the graft-host junction with well-defined biomicroscopic limits. Preoperatively, the mean keratometric measures were K1: 44.8 ± 4.8 D and K2: 54.1 ± 4.8 D and postoperatively K1: 47.5 ± 3.5 D and K2: 50.8 ± 2.6 D. The mean improvement in corrected visual acuity was 10 lines, and mean cylinder improved from 9.3 ± 2.1 D to 3.3 ± 1.4 D. All cases showed anatomical and refractive improvement. With long-term follow-up, late post-PK ectasia becomes an increasing problem. PALK can be a successful surgical option to reinforce the ectatic area while preserving a functional clear PK. By adding donor corneal tissue, PALK restores the ectatic area, improves visual acuity, keratometric values, and astigmatism, and preserves the functional graft while avoiding the higher risks of a larger diameter PK.

Effect of Autogenous Bone Marrow Aspirate Treatment on Magnetic Resonance Imaging Integration of Osteochondral Allografts in the Knee: A Matched Comparative Imaging Analysis

To accurately evaluate the effects of bone marrow aspirate (BMA) augmentation on osteochondral allograft (OCA) integration on early postoperative magnetic resonance imaging (MRI) using the comprehensive Osteochondral Allograft MRI Scoring System (OCAMRISS). This imaging study compared patients who underwent OCA transplantation with and without BMA augmentation for the treatment of focal osteochondral defects in the knee performed by a single surgeon between July 2013 and July 2017. Patients were excluded if they underwent implantation of premade plugs, had an overlapping OCA configuration ("snowman" technique), or did not undergo MRI at 6months postoperatively. Patients were matched by lesion location, lesion size, age, and body mass index, as well as whether they underwent previous surgical procedures. Data were analyzed using descriptive statistics, Spearman correlation, the independent t test, the Mann-Whitney U test, and the χ2 test. A total of 58 patients (29 per group) were included in this study, with an average age of 36.4 ± 10.1years and mean body mass index of 28.6 ± 5.1. The mean size of the analyzed OCA plugs was 3.3 ± 1cm2. At an average imaging follow-up of 5.6 ± 1months, 86.2% of the grafts had achieved osseous integration at the graft-host junction and 75.9% did not show any cystic changes in the subchondral bone. No difference in any OCAMRISS subscale was seen comparing OCAs with and without BMA augmentation (P>.05). Specifically, osseous integration and subchondral cyst formation were comparable between groups (P= .128 and P= .539, respectively). OCAs showed excellent osseous integration at the graft-host junction on 6-month postoperative MRI. The treatment of OCAs with autogenous BMA did not result in superior imaging outcomes when analyzed using the OCAMRISS. Level III, case-control study.

Graft Thickness is Associated with Subchondral Cyst Formation in Patients After Osteochondral Allograft Transplantation in the Knee

Objectives: The purpose of this study was to determine potential predictive associations between preoperative patient characteristics or osteochondral allograft (OCA) morphology, and postoperative OCA appearance assessed by the osteochondral allograft magnetic resonance imaging scoring system (OCAMRISS) at 6-month follow-up. It was hypothesized that preoperative patient factors or OCA morphology are associated with postoperative OCAMRISS scores. Methods: This study evaluated 74 OCAs that were implanted in the femoral condyles of 63 patients for the treatment of symptomatic osteochondral defects in the knee.Postoperative MRI was obtained at an average follow-up of 5.5 ± 1.0 months. A musculoskeletal radiologist scored all grafts according to the OCAMRISS. Pearson’s correlation, Mann Whitney U test and chi-square test were used to distinguish associations between age, sex, smoker status, BMI, previous surgeries, concomitant surgeries, bone marrow augmentation, graft location, graft size, bony graft thickness, and OCAMRISS subscales. Results: At 6-month postoperative MRI evaluation, the mean OCAMRISS score was 3.9 ± 2 with 87.8% of OCAs presenting with crossing trabeculae indicating osseous integration, and 21.6% showing cystic formation of the graft and host-graft junction. When correlating patient and lesion characteristics with OCAMRISS subscales, following associations were identified: cartilage signal and age (p=0.021), subchondral bone plate congruity and bone marrow aspirate augmentation (p=0.046), cystic changes and bony graft thickness (p=0.019), opposing cartilage and prior surgery (p=0.045) and BMI (p=0.003), and synovitis and age (p=0.044) and positive smoking status (p=0.009). Osseous integration was not associated with any preoperative factor. Conversely, patient’s sex, OCA graft size and location did not correlate with any OCAMRISS subscale (p &gt; 0.05). OCA bony thickness was the only plug-specific factor being associated with the OCAMRISS, and the only factor related to cystic formation at 6 months (p = 0.019). Grafts that presented with cystic formation were significantly thinner than grafts that did not show cystic changes at the host-graft junction (p = 0.008). Grafts with less than 5 mm bony thickness had an almost 5-fold increased risk of demonstrating cystic changes on MRI (odds ration [OR]= 4.9; 95% Confidence Interval [CI]= 1.5 - 16.1; p = 0.006). Conversely, OCAs thickness was not associated with osseous integration, except grafts with a bony thickness of more than 9 mm presented significantly more often with a discernible cleft than did shallower grafts (p = 0.049). Conclusion: Osteochondral allograft thickness is associated with subchondral cyst formation at short-term follow-up. Shallow grafts demonstrate a substantially increased risk of developing subchondral cysts at the graft-host junction after OCA transplantation. Conversely, thicker grafts may negatively affect osseous graft integration. Hence, the authors suggest a bony graft thickness of 5-9 mm for OCAs to mitigate the risk of cystic formation and delay of osseous integration after cartilage resurfacing. [Table: see text]

Decreased Graft Thickness Is Associated With Subchondral Cyst Formation After Osteochondral Allograft Transplantation in the Knee

Background: Subchondral changes, specifically cyst formation, are a known finding after osteochondral allograft (OCA) transplantation. Purpose/Hypothesis: The purpose was to determine potential predictive associations between preoperative patient characteristics or OCA morphology and postoperative OCA appearance as assessed by the osteochondral allograft magnetic resonance imaging scoring system (OCAMRISS) at 6-month follow-up. It was hypothesized that preoperative patient factors or OCA morphology is associated with postoperative OCAMRISS scores. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This study evaluated 74 OCAs that were implanted in the femoral condyles of 63 patients for the treatment of symptomatic osteochondral defects in the knee. Postoperative magnetic resonance imaging was obtained at a mean ± SD follow-up of 5.5 ± 1.0 months. A musculoskeletal radiologist scored all grafts according to the OCAMRISS. Point biserial correlation, Mann-Whitney U test, Fisher exact test, and chi-square test were used to distinguish associations between OCAMRISS subscales and age, sex, smoker status, body mass index, previous surgery, concomitant surgery, bone marrow augmentation, graft location, graft size, and bony graft thickness. Results: OCA bony thickness showed significant correlation with cystic changes at the graft-host junction (P = .019). Grafts with cystic formation were significantly thinner than grafts without cystic changes (P = .008). The odds ratio for grafts with <5-mm bony thickness demonstrating cystic changes was 4.9 (95% CI, 1.5-16.1; P = .009). Bony graft thickness was not associated with graft integration, but 40% of grafts with a bony thickness >9 mm presented with a residual osseous cleft, as opposed to 11.3% of thinner grafts (P = .1). The augmentation with bone marrow aspirate did not affect osseous graft integration or subchondral cystic formation (P = .375 and P = .458, respectively). Conclusion: Osteochondral allograft thickness is associated with subchondral cyst formation at short-term follow-up. Thin grafts demonstrate a substantially increased risk of developing subchondral cysts at the graft-host junction after OCA transplantation. Conversely, thicker grafts may negatively affect osseous graft integration. Hence, surgeons should be aware of the potential pitfalls of transplanting thin or thick grafts regarding cystic formation and delay of osseous integration after cartilage resurfacing.

Successful Treatment of Corneal Opacification with Associated Thickened Epithelium by Simple Peeling: Acquired Corneal Subepithelial Hypertrophy (ACSH)

PurposeTo study clinical and histopathological findings of corneal opacification caused by thickened epithelium leading to reduced vision and topographical changes and to evaluate the outcome of its removal. MethodsTwelve patients (17 eyes) with central, paracentral or peripheral corneal opacification were reviewed to obtain their visual acuity, describe their slit lamp (SL) appearance (depth, extent and density) and document their topographic changes before and after peeling of the epithelium under SL or surgical removal under the microscope. Specimens of six cases were available for histopathological examination and immunohistochemical staining. ResultsMost of the eye opacifications were secondary to corneal procedures in 10 [Penetrating keratoplasty (PKP) in 7 for congenital glaucoma, keratoconus or adherent leukoma – usually over graft-host junction –, Photorefractive keratectomy (PRK) in 2 and Phototherapeutic keratectomy in one], chronic inflammation following trachoma or non-specific causes (3), and herpetic scar (1). Three cases were considered to be idiopathic. All cases presented with decreased vision, astigmatism or changes in topography or refraction. Their vision, clinical symptoms and topography improved after treatment. Histopathologically, all six cases shared findings that are similar to what have been described as peripheral hypertrophic subepithelial corneal degeneration (PHSCD) rather than Salzmann’s nodular degeneration. None of the cases showed inflammation or subepithelial pannus formation in the excised tissue. However, our cases did not fit into the diagnosis of PHSCD because of the location of the corneal opacification (being peripheral in 41% of the corneas, the presence of underlying primary etiologic factors in 82% of the eyes and the bilateral occurrence in 5 patients. ConclusionsMeticulous SL examination aided by corneal imaging may accurately diagnose and determine the depth of corneal opacification as a cause for reduced vision. Histopathologically, the removed tissue is similar to PHSCD, but cases differ in their clinical profile. Peeling the thickened epithelial/subepithelial tissue is curative in most patients, improves visual and clinical outcome and avoids unnecessary corneal grafting.

Bone Marrow Aspirate Concentrate Does Not Improve Osseous Integration of Osteochondral Allografts for the Treatment of Chondral Defects in the Knee at 6 and 12 Months: A Comparative Magnetic Resonance Imaging Analysis

Background: Poor osseous integration after fresh osteochondral allograft transplantation (OCA) may be associated with graft subsidence and subchondral bone collapse after implantation. The augmentation of OCA with bone marrow aspirate concentrate (BMAC) has been hypothesized to improve osseous incorporation of the implanted allograft. Purpose: To evaluate the effect of autogenous BMAC treatment on osseous integration at the graft-host bony interface after OCA. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review of patients treated with OCA+BMAC or OCA alone for full-thickness chondral defects of the distal femur from March 2015 to December 2016 was conducted. Seventeen knees treated with OCA+BMAC and 16 knees treated with OCA alone underwent magnetic resonance imaging (MRI) in the early postoperative phase (mean, 6 months). Eighteen knees treated with OCA+BMAC and 16 knees treated with OCA alone underwent MRI in the late postoperative phase (mean, 12 months). Bone, cartilage, and ancillary features on MRI were graded using the Osteochondral Allograft MRI Scoring System (OCAMRISS) by a musculoskeletal radiologist blinded to the patient’s history and treatment. Results: There were no significant differences in the demographics or lesion characteristics between treatment groups in either postoperative phase. In the early postoperative phase, the mean OCAMRISS bone score was 3.0 ± 0.7 and 3.3 ± 0.7 for the OCA+BMAC group and OCA alone group, respectively (P = .76); 71% (OCA+BMAC) and 81% (OCA alone) of MRI scans demonstrated discernible clefts at the graft-host junction (P = .69), and 41% (OCA+BMAC) and 25% (OCA alone) of MRI scans demonstrated cystic changes at the graft and graft-host junction (P = .46). In the late postoperative phase, the mean OCAMRISS bone score was 2.7 ± 0.8 and 2.9 ± 0.8 for the OCA+BMAC group and OCA alone group, respectively (P = .97); 44% (OCA+BMAC) and 63% (OCA alone) of MRI scans demonstrated discernible clefts at the graft-host junction (P = .33), and 50% (OCA+BMAC) and 31% (OCA alone) of MRI scans demonstrated the presence of cystic changes at the graft and graft-host junction (P = .32). The mean OCAMRISS cartilage, ancillary, and total scores were not significantly different between groups in either postoperative phase. Conclusion: OCA augmented with BMAC was not associated with improved osseous integration; decreased cystic changes; or other bone, cartilage, and ancillary feature changes compared with OCA alone.

Descemet Stripping Automated Endothelial Keratoplasty for Failed Penetrating Keratoplasty: Influence of the Graft-Host Junction on the Graft Survival Rate.

To investigate the clinical results of Descemet stripping automated endothelial keratoplasty (DSAEK) for failed penetrating keratoplasty (PK) and the influence of the graft-host junction (GHJ) on the graft survival rate. Data were retrospectively collected on patient demographics, visual outcomes, complications, and graft survival rate for 17 eyes of 16 patients who underwent DSAEK for failed PK. The graft survival rate was compared between the eyes when divided into a bump group and a well-aligned group according to the shape of the GHJ detected on anterior segment optical coherence tomography. The most common indication for initial PK was bullous keratopathy after glaucoma surgery (35.3%). Seven eyes (41.2%) were classified into the bump group and 10 eyes (58.8%) into the well-aligned group. The mean best-ever documented visual acuity (BDVA) after DSAEK was 0.33 logMAR. Postoperatively, almost 70% of eyes achieved a BDVA that was within 0.2 logMAR of their preoperative BDVA. Graft detachment occurred in 29.4% of eyes and primary graft failure in 17.6%. All primary failures occurred in the bump group. The cumulative graft survival rate was 82.3% at 1 year, 73.2% at 2 years, and 58.6% at 3 years. Graft failure was more likely in eyes in the bump group than in those in the well-aligned group (P = 0.037, Wilcoxon test). DSAEK for failed PK had a favorable outcome in this study. However, the GHJ should be assessed carefully before performing the procedure.

Lamellar keratoplasty techniques.

Lamellar keratoplasty (LK) has revolutionized corneal graft surgery in several ways. Deep anterior LK (DALK) has eliminated risk of failure due to endothelial rejection. Endothelial keratoplasty (EK) has almost eliminated induced astigmatism and the “weak” graft–host junction as seen with penetrating keratoplasty (PK) and also reduced the risk of endothelial rejection. LK provided new insights into posterior corneal anatomy that led to better understanding and performance of DALK and to the development of another EK procedure, namely pre-Descemet's EK (PDEK). Surgical procedures for LK were further refined based on the improved understanding and are able to deliver better surgical outcomes in terms of structural integrity and long-term patient satisfaction, reducing the need of further surgeries and minimizing patient discomfort. In most specialist centers, anterior lamellar techniques like DALK and EK techniques like Descemet's stripping EK (DSEK) and Descemet's membrane EK (DMEK) have replaced the full-thickness PK where possible. The introduction of microkeratome, femtosecond laser, and PDEK clamp have made LK techniques easier and more predictable and have led to the innovation of another LK procedure, namely Bowman membrane transplant (BMT). In this article, we discuss the evolution of different surgical techniques, their principles, main outcomes, and limitations. To date, experience with BMT is limited, but DALK has become the gold standard for anterior LK. The EK procedures too have undergone a rapid transition from DSEK to DMEK and PDEK emerging as a viable option. Ultrathin-DSEK may still have a role in modern EK.

A pilot study to evaluate the efficacy of fibrin glue in attaching full thickness skin graft in repair of cicatricial ectropion

Background: Traditionally, sutures are used to attach skin graft. Periocular skin reconstruction is peculiar in respect of constant movement of the graft bed due to lid movements. This study was aimed at evaluating the use of fibrin glue in skin graft for cicatricial ectropion.Methods: This was prospective, non-randomized, interventional study. Total 10 patients with cicatricial ectropion were recruited. After dissection of scar, skin defect was covered with full thickness post auricular graft. Fibrin glue used to attach the graft over host bed. Bolster tied and bandage applied. Patients were evaluated for graft stability, opposition of graft host junction and graft uptake.Results: The mean age was 30.9 years. Patients were divided into three groups i.e. 20-30 years, 30-40 years and 40-50 years. There were 05 patients (50%) in first group, 03 patients (30%) in second group and 02 patients (20%) in third group. Majority (90%) were male. Following injury 70% patients reported between 1-3 years. Grade 3 ectropion was most common (60%). Average duration of surgery was 79.3 min (standard deviation of 14.15 min). Horizontal dimensions of graft, 32 mm maximum and 26 mm minimum (average 29 mm). Vertical dimensions of graft, 18 mm maximum and 12 mm minimum (average 15 mm). Graft uptake was complete in all cases. No cases of graft infection or necrosis. However, 03 patients had residual ectropion.Conclusions: Use of fibrin glue in attaching full thickness skin graft is an effective and safe technique with good uptake and stable graft host junction.

Non-vascularised fibula grafts for reconstruction of segmental and hemicortical bone defects following meta- /diaphyseal tumour resection at the extremities

BackgroundThe reconstruction of meta−/diaphyseal bone defects following bone tumour resection is challenging, and biological treatment options should be applied whenever possible, especially in benign lesions and early stage sarcomas. We aimed to evaluate the results of segmental (SR) and hemicortical reconstructions (HR) at the extremities using non-vascularised fibula grafts.MethodsWe retrospectively enrolled 36 patients who were treated with non-vascularised fibula reconstructions (15 SR, 21 HR) after bone tumour resection (15 malignant, 21 benign). All cases were evaluated regarding consolidation, hypertrophy at the graft-host junctions, and complications; moreover, the functional and oncological results were assessed. The mean follow-up was 8.3 years (2.1–26.6 years).ResultsPrimary union was achieved in 94% (SR 87%, HR 100%) of patients, and 85% (SR 81%, HR 88%) showed hypertrophy at the graft-host junction. The overall complication rate was 36% with 4 patients (11%) developing local recurrence. There was a significant correlation between the development of mechanical complications (fracture, delayed-/non-union) and a defect size of ≥12 cm (p = 0.013), segmental defects (p = 0.013) and additional required treatment (p = 0.008). The functional outcome was highly satisfactory (mean MSTS score 86%).ConclusionsDue to encouraging results and advantages (such as their remodelling capacity at the donor site), non-vascularised fibula reconstructions should be considered a valuable alternative treatment option for patients with hemicortical defects or segmental reconstructions of less than 12 cm in which no additional neo-/adjuvant treatment is necessary.

Surgical management of spontaneous, late-onset Descemet membrane detachment after penetrating keratoplasty for keratoconus: a case report

BackgroundTo report a surgical method for treating corneal oedema in a case of late-onset Descemet membrane detachment after penetrating keratoplasty.Case presentationA 55-year old patient presented with sudden visual loss in his left eye 28 years after penetrating keratoplasty for keratoconus. Slit-lamp biomicroscopy revealed a distortion of the corneal graft anatomy with protrusion of the graft and peripheral thinning and steepening in the residual host tissue, accompanied by corneal graft oedema. Anterior segment optical coherence tomography revealed detachment of Descemet membrane localized to the area of the graft oedema. We proceeded with a full-thickness, partially circumferential incision in the graft-host junction, followed by repositioning and re-suturing of the graft in place, and intracameral air injection in order to achieve reattachment of Descemet membrane.ConclusionsCorneal graft repositioning in combination with re-bubbling may represent an effective therapeutic option in keratoconic patients with peripheral thinning in the residual host corneal tissue and subsequent Descemet membrane detachment.