Changing Indications in Penetrating Keratoplasty: A Systematic Review of 34 Years of Global Reporting.

BACKGROUND: Penetrating keratoplasty (PK) ranks among the oldest and most common kinds of human tissue transplantation. Based on the hypothesis that reported indications for PK significantly vary between global regions and over time, the present systematic review aimed to provide a thorough overview of global PK indications as reported in peer-reviewed manuscripts. METHODS: A literature search of PubMed and MEDLINE was conducted to retrieve articles published from January 1980 to May 2014. Indications for PK within 7 global regions were compared using a modified classification system for PK indications and analyzed via multivariate regression. RESULTS: A total of 141 publications from 37 countries were included, recording 180 865 PK cases. Postcataract surgery edema was the predominant indication in North America (28.0%) and ranked second in Europe (20.6%), Australia (21.1%), the Middle East (13.6%), Asia (15.5%), and South America (18.6%). Keratoconus was the leading indication in Europe (24.2%), Australia (33.2%), the Middle East (32.8%), Africa (32.4%), and South America (22.8%). It ranked third in North America (14.2%). Keratitis was the primary indication in Asia (32.3%). Fuchs endothelial corneal dystrophy was the fourth most common indication in North America (12.9%) and Europe (10.2%) and fifth in South America (3.8%). Multivariate analysis supported these results and revealed individual regional changes over time. CONCLUSIONS: Systematic analysis reveals characteristic chronological and regional differences in reported global PK indications. Leading reported indications for PK between 1980 and 2014 were keratoconus (Europe, Australia, the Middle East, Africa, and South America), pseudophakic bullous keratopathy/aphakic bullous keratopathy (North America), and keratitis (Asia).

Role of the Endothelial Layer in the Deswelling Process of Organ-Cultured Human Corneas Before Transplantation.

PURPOSE: Before corneal transplant surgery, a deswelling process of organ-cultured corneas is required. This study compares the deswelling kinetics of corneas with an intact endothelial cell layer and disrupted or removed endothelium by measuring central corneal thickness (CCT) over time using anterior segment spectral domain optical coherence tomography. METHODS: Ten donor pairs were cultured in organ culture. The right and left corneas were alternately assigned to one of 2 deswelling groups. Deswelling in the first group [endothelial group (EG)] was induced using a medium with dextran 5%. Corneas of the second group [nonendothelial group (NEG)] were deprived of their endothelial cell layer by trypsinization and were then placed in the same deswelling medium. CCT (mean ± SD) was measured by anterior segment spectral domain optical coherence tomography before deswelling (0 hours) and after 1, 2, 3, 6, 12, 24, 48, 72, and 144 hours. Deswelling kinetics was analyzed through the nonlinear platform in SAS/JMP11 Pro. RESULTS: Before deswelling, CCT was 1071.0 µm (±129.6 µm) and 1133.8 µm (±124.3 µm) in the EG and NEG, respectively. Minimum corneal thickness was obtained after 24 hours in the EG (531.9 ± 47.5 µm) and 6 hours in the NEG (645 ± 81.2 µm). CCT was significantly (P < 0.01) higher in the NEG than EG after more than 6 hours. CONCLUSIONS: Corneal dehydration after organ culture seems to be a multifactorial process, which not only depends on osmotic effects of the deswelling compound but also requires the presence of an intact endothelial cell layer.

Conjunctival and intraocular swabs for the microbiological assessment of donor corneas.

PURPOSE: In this study, we investigated the associations between conjunctival (co) and intraocular (io) swabs and their implications for the contamination rates of organ-cultured corneas. METHODS: A total of 4177 swabs from 1054 corneas of 527 donors were acquired from the conjunctiva, after disinfection with 5% polyvinylpyrrolidone-iodine solution, and also from the anterior chamber after corneoscleral trepanation (io). Samples were incubated at 22.5 ± 2.5°C and 32.5 ± 2.5°C in thioglycollate broth for 14 days. Donor corneas were cultured in a closed system at 31°C. Microbial differentiation was performed for positive cultures. RESULTS: A higher temperature (32.5°C) and the intraocular swab retrieving localization led to significantly higher swab positive rates (32.5°C versus 22.5°C, odds 1.65, p < 0.0001; io versus co, odds 1,53, p < 0.0001). Death-to-collection time and laterality (left or right eye) had no significant influence on swab positivity. The cause of death significantly influenced the positive rates (p < 0.0001). Detection at 32.5°C occurred significantly earlier than at 22.5°C (p < 0.0001). The overall comparison of detected species showed no significant differences in the variety between intraocular and conjunctival swabs. During the study period, six contaminations of organ-cultured corneas occurred: four times Pseudomonas aeruginosa and once each Candida albicans and Staphylococcus hominis were found. Swap results and cornea contaminations were not significantly correlated. CONCLUSIONS: Co and io swabs show high microbial colonization rates, even after standard disinfection. Io swabs generally reproduce the co microbial range, most likely due to a mobilization and diversion of microorganisms during the trepanation procedure. Swab results do not yield a valuable tool to predict contaminations of organ-cultured corneas.

A disposable system for rapid purification of autologous plasmin as an adjunct to vitrectomy - performance and safety profile.

BACKGROUND: The generation of an atraumatic posterior vitreous detachment (PVD), a common goal in vitreoretinal surgery, is a challenge particularly in children and young trauma patients. Plasmin has been proposed as a surgical adjunct to enzymatically generate a PVD. This study assesses the performance and safety of a new system for rapid purification of plasmin as an adjunct to vitrectomy. METHODS: Plasminogen was isolated from human plasma by affinity chromatography using a disposable rapid purification kit, and activated to plasmin with streptokinase. Activities were assessed spectrophotometrically. For safety studies, 38 rabbits received intravitreal injections of one of the following compounds in 0.1 ml respectively: 4.7, 12.7 and 24 IU plasmin, 15 mg dextran, 4,100 U streptokinase, 500 µg ε-aminocaproic acid, 0.1 M potassium phosphate or balanced salt solution (BSS). Thirty min after injection, a two-port vitrectomy was performed. Rabbits were followed clinically and with bright flash electroretinography (ERG) for up to 9 months. The eyes were investigated by light and transmission electron microscopy. RESULTS: The specific plasmin activity obtained from blood of healthy volunteers averaged 42.3 ± 6.6 IU/ml (range 21.6 IU/ml to 54.5 IU/ml). The identity and purity of the enzyme was confirmed by several methods. Clinically, a mild to moderate inflammatory response was seen in most eyes on day 1, but had disappeared by day 7. ERG showed moderate depressions of a- and b-wave amplitudes on day 2, particularly in the potassium phosphate (a: -29.16 ± 4.56, b: -21.23 ± 6.31), 4.7 (a: -34.38 ± 6.64, b: -26.66 ± 6.06) and 24 IU (a: -38.25 ± 4.05, b: -23.38 ± 4.29) plasmin groups, but also in the BSS- (a: -11.19 ± 21.78, b: -11.41 ± 15.47) and dextran- (a: -17.86 ± 14.18, b: -6.67 ± 18.14) treated eyes. ERG changes recovered during follow-up. One rabbit each from the 12.7 and the 24 IU plasmin groups showed a minimal discoloration of one medullary ray after 9 months. Histology did not reveal morphologic signs of toxicity. CONCLUSION: The isolation system generated plasmin with a high degree of purity. A failure-mode analysis did not reveal significant risks of toxicity. A single preparation can provide a maximum dose of 10.9 IU/200 µl, the likely target clinical dose being 1.88 IU. Plasmin doses of at least 12.7 IU appear be safe when injected into rabbit eyes, followed by vitrectomy.

New treatment option for adult-onset limbal xanthogranuloma.

PURPOSE: The purposes of this study are to report a case of adult-onset juvenile xanthogranuloma and suggest a new treatment option. METHODS: A 35-year-old man presented with an isolated mass of the limbus. Biopsy revealed a histiocytic tumor with Touton's giant cells staining positive for CD68 and S-100 but negative for CD1a, consistent with JXG. Two intratumoral injections of triamcinolone acetonide 6 weeks apart were performed. The main outcome measure was 6-months follow up clinically and by ultrasound biomicroscopy. RESULTS: The lesion regressed, and corneal thickness returned to normal 3 months after the first injection. An increase in intraocular pressure required topical treatment. No recurrence was seen throughout follow up. CONCLUSION: Limbal juvenile xanthogranuloma can be successfully treated with intralesional triamcinolone acetonide, thus avoiding a lamellar keratectomy approach.

Effect of intravitreal plasmin on vitreous removal through a 25-gauge cutting system in the rabbit in vivo.

PURPOSE: Intravitreal plasmin creates a posterior vitreous detachment, but may also liquefy the vitreous. This study measures the rate of vitreous removal from rabbit eyes after plasmin injection in vivo. METHODS: Intravitreal injections of 150 IU hyaluronidase (n = 5), 0.5 activity units (AU, n = 6) or 0.9 AU of streptokinase-activated human plasmin (n = four groups of 6) in 0.1 ml were performed in rabbits, the fellow eyes received 0.1 ml BSS. After 30 min (hyaluronidase), 30 min, 4 h, 12 h or 24 h (0.9 AU plasmin) or 24 h (0.5 AU plasmin), 1 ml of vitreous was removed from each eye without infusion, using a 25-gauge cutter and a standardized protocol. Animals were sacrificed after surgery. RESULTS: Compared to fellow eyes, the average rate of vitreous removal was increased by hyaluronidase by 68.9 +/- 6.3% (p < 0.05) and by 0.5 AU plasmin (24 h) by 26.8 +/- 3.3% (p < 0.05). 0.9 AU of plasmin increased removal rates by 0.8 +/- 10% (n.s.), 15.4 +/- 6.3% (p < 0.05), 40.3 +/- 3.1% (p < 0.05), and 71.9 +/- 32.4% (p < 0.05) after 30 min, 4 h, 12 h and 24 h incubation respectively. The ratios of removal rates of treated/control eyes in the 0.9 AU groups showed a linear correlation with incubation time (r = 0.783, p < 0.0001). CONCLUSION: Intravitreal plasmin increases the rate of vitreous removal in rabbits.

Recurrent suprachoroidal dislocation of an anterior chamber intraocular lens.

We present a patient with a history of posterior chamber intraocular lens (PC IOL) implantation and trabeculotomy 9 years previously who recently had IOL exchange for an angle-based anterior chamber IOL. Twenty-four hours after the exchange, he was referred to us with hypotony and "loss" of the IOL. Ultrasound revealed a rigid choroidal detachment and echoes suggestive of a suprachoroidally dislocated IOL. Anterior vitrectomy and resuturing of the incision were performed. Subsequently, the IOL repeatedly migrated in and out of the suprachoroidal space, allowing atraumatic removal. Angle-based IOL implementation should be avoided in eyes with a history of trabeculotomy or cyclodialysis.

Sterilization and preservation influence the biophysical properties of human amnion grafts.

The introduction of amniotic membrane (AM) transplantation in ophthalmic surgery holds great promise and in many clinical situations it offers an alternative to existing management options. The purpose of this study was to examine the influence of established sterilization and preservation procedures on biophysical and histological properties of AM grafts. Amnion was sterilized by peracetic acid/ethanol sterilization [PES] and preserved by air-drying (sterile laminar flow) [AD] or in glycerol [GLYC]. Unsterilized AM were preserved at -80 degrees C [-80 degrees C] and served as an experimental control. Amnion allografts were characterized by the determination of their thickness, moisture vapour permeability (MVP), oxygen permeability (OPERM), tensile strength and sulphur content. Immunostaining for tissue-specific and basement membrane-related proteins was performed. Differences in biophysical parameters were found between the unsterilized allografts and the sterilized, air-dried or glycerol-preserved allografts. [PES/AD] showed the highest MVP and OPERM, the highest tensile strength and the lowest sulphur content and thickness. [PES/GLYC] exhibited the lowest OPERM and the highest thickness compared to [-80 degrees C] and [PES/AD]. Collagen types V and VII were preserved the best in the control group. Sterilization and preservation affect biophysical properties important for the use of AM as allogenic grafts. It has to be determined if any change, as noted, has a clinical impact.

Indocyanine-green-assisted internal limiting membrane peeling in macular hole surgery--a follow-up study.

BACKGROUND: Macular hole surgery including vitrectomy and peeling of epiretinal membranes and the internal limiting membrane (ILM) has become a standard procedure in retinal surgery. Poor visualization of the ILM is an obstacle for successful surgery. Recently, indocyanine green (ICG) has been reported to be a helpful intraocular substance in identifying these membranes. PATIENTS AND METHODS: Eighteen eyes with macular holes stages 2-4 were included. Intraoperatively, the ILM was stained with three drops of 1:9-diluted ICG. After 1 min incubation, the vitreous cavity was rinsed with Ringer's lactate solution, and the ILM was peeled. Autologous thrombocytes were applied to the macular hole and the eye was endotamponaded with 20% SF-6 gas. Preoperatively, 6 weeks postoperatively, and in 3-month intervals thereafter, visual acuity, fundus photographs, scanning laser ophthalmoscope imaging, and Humphrey 24-2 static perimetry was performed. RESULTS: Intraoperatively, the ILM could be nicely visualized by ICG, which allowed easier and less traumatic peeling. At 6 weeks follow-up, visual acuity had improved in 14 of 18 patients, and the macular hole was closed 6 weeks after surgery. Scanning laser imaging revealed a strong signal. During prolonged follow-up, visual acuity declined due to cataract formation. CONCLUSION: ICG as an intraocular tool for staining of the ILM is helpful in macular hole surgery. We observed no negative effects on retinal function, but patients should be followed.

[Macular hole surgery: experience with autologous platelet concentrate and indocyanine green-assisted internal limiting membrane peeling]. / Chirurgie des idiopathischen Makulaforamens: Erfahrungen mit autologem Thrombozytenkonzentrat und Indocyaningrünapplikation.

BACKGROUND: To report on our clinical experience with autologous platelet concentrate and indocyanine green(ICG)-assisted internal limiting membrane (ILM) peeling in macular hole surgery. PATIENTS AND METHODS: Standard 3-port vitrectomy was performed in 107 eyes of 101 patients (m: f = 27 : 74; mean age 60 +/- 9, range 30 - 80 years) with idiopathic macular hole stages II - IV. After fluid/air exchange, autologous platelet concentrate was applied (1.9 +/- 0,1 x 10(8) thrombocytes). ILM peeling, which was preceded by ICG staining in 19 eyes, was performed in 34 patients. RESULTS: After one procedure, anatomic success (hole closure) could be achieved in 85 % (n = 68), 75 % (n = 27) and 100 % (n = 3) of the eyes with stage II, III and IV holes, respectively. The mean visual acuity improved by 1 line. The overall initial closure rate of 82 % could be further enhanced to 96 % with a second procedure. In eyes pretreated with ICG, an initial rate of hole closure in 94 % and an improvement of visual acuity by 2 lines was observed. CONCLUSION: Autologous platelet concentrate appears to be a safe and reliable adjunct to improve the anatomical outcome of conventional macular hole surgery. Functional results can be further enhanced by ICG-assisted ILM peeling