The dualistic role of the purinergic P2Y12-receptor in an in vivo model of Parkinson's disease: Signalling pathway and novel therapeutic targets.

Parkinson's disease (PD) is a chronic, progressive neurodegenerative condition; characterized with the degeneration of the nigrostriatal dopaminergic pathway and neuroinflammation. During PD progression, microglia, the resident immune cells in the central nervous system (CNS) display altered activity, but their role in maintaining PD development has remained unclear to date. The purinergic P2Y12-receptor (P2Y12R), which is expressed on the microglia in the CNS has been shown to regulate microglial activity and responses; however, the function of the P2Y12R in PD is unknown. Here we show that MPTP-induced PD symptoms in mice are associated with marked neuroinflammatory changes and P2Y12R contribute to the activation of microglia and progression of the disease. Surprisingly, while pharmacological or genetic targeting of the P2Y12R augments acute mortality in MPTP-treated mice, these interventions protect against the neurodegenerative cell loss and the development of neuroinflammation in vivo. Pharmacological inhibition of receptors during disease development reverses the symptoms of PD and halts disease progression. We found that P2Y12R regulates ROCK and p38 MAPK activity and control cytokine production. Our principal finding is that the receptor has a dualistic role in PD: functional P2Y12Rs are essential to initiate a protective inflammatory response, since the lack of the receptor leads to reduced survival; however, at later stages of neurodegeneration, P2Y12Rs are apparently responsible for maintaining the activated state of microglia and stimulating pro-inflammatory cytokine response. Understanding protective and detrimental P2Y12R-mediated actions in the CNS may reveal novel approaches to control neuroinflammation and modify disease progression in PD.

Extracellular matrix changes in corneal opacification vary depending on etiology.

Purpose: The purpose of this study is to examine the expression of tenascin-C and matrilin-2 in three different disorders, which frequently require corneal transplantation. These pathological conditions include bullous keratopathy (BK), Fuchs' endothelial corneal dystrophy (FECD), and corneal scarring in herpetic keratitis. Methods: Histological sections of corneal buttons removed during keratoplasty were analyzed in BK (n = 20), FECD (n = 9), herpetic keratitis (n = 12), and cadaveric control (n = 10) groups with light microscopy following chromogenic immunohistochemistry. The sections were evaluated by three investigators, and semiquantitative scoring (0 to 3+) was applied according to standardized methods at 400X magnification. Each layer of the cornea was investigated; moreover, the stroma was subdivided into subepithelial, middle, and pre-Descemet's membrane areas for more detailed analysis. Results: Excessive epithelial and stromal expression of tenascin-C was identified in all investigated conditions; the results were most pronounced in the pre-Descemet's membrane. Regarding matrilin-2, when examined in BK, there was increased labeling intensity in the epithelium (p<0.001) and stromal layers (p<0.05), and a decrease in the endothelium (p<0.001). In the other investigated conditions, only a low degree of stromal localization (p<0.05) of matrilin-2 was detected. Conclusions: The expression of tenascin-C and matrilin-2 differs when examined in various corneal pathologies resulting in opacification. Both molecules seem to be involved in regeneration and wound healing of the corneal matrix in these diseases.

[Femtosecond laser-assisted keratoplasty]. / Femtoszekundumlézeres keratoplasztika.

INTRODUCTION AND AIM: To present our results on femtosecond laser-assisted penetrating keratoplasty. PATIENTS AND METHOD: Twenty-five eyes of 25 patients underwent surgery with the following indications: pseudophakic bullous keratopathy (n = 10), keratoconus (n = 4), corneal dystrophy (n = 5), corneal scar (n = 4), band keratopathy (n = 2). Trephination of both the donor and recipient corneas were performed with VisuMax femtosecond laser device (Carl Zeiss Meditec AG, Jena, Germany). In each case, trephinaton of the donor tissue was performed first with an artificial anterior chamber (Moria, Antony, France). For the surgical plan and in the postoperative period we obtained different corneal imaging modalities. The corneal power was measured with corneal topography (TMS-4, Tomey, Nürnberg, Germany) and Scheimpflug tomography (Pentacam HR, Oculus, Wetzlar, Germany). The central corneal thickness was evaluated with Pentacam and corneal endothelial cell density was measured with specular microscopy (SP3000P, Topcon, Tokyo, Japan). The corneal structure was imaged with anterior segment optical coherence tomography (Visante, Carl Zeiss Meditec AG). All measurements were performed every 3 months in the first year and yearly thereafter. The follow-up period was 3 years in every case. RESULTS: The corrected decimal visual acuity showed an improvement from a preoperative 0.1 ± 0.1 to a postoperative 0.71 ± 0.18 value at the end of the follow-up period (p = 0.03). All corneal grafts maintained their transparency, there were no immunological rejection during the follow-up. Topographical astigmatism was 4.5 ± 3.1 D in the first month; it showed a decreasing tendency, but there was no significant change in the 3-year period. The mean central corneal thickness changed with 60 µm during the follow-up; there was no significant difference between the first month (564 ± 52 µm) and the third year (596 ± 64 µm) mean pachymetry values (p = 0.1). The mean endothelial cell density decreased first, then remained stable, but did not change significantly from the first (1641 ± 433 cells/mm2) to the last postoperative visit (1220 ± 391 cells/mm2, p = 0.1). CONCLUSIONS: In the case of femtosecond laser-assisted penetrating keratoplasty, trephination of the donor and recipient cornea is performed automatically in a highly precise fashion. The accurate cutting surface provides excellent wound apposition and healing. Both anatomical and functional rehabilitation of patients undergoing surgery are favourable and fast. Orv Hetil. 2018; 159(17): 671-676.

[Diagnostics and treatment of infectious keratitis]. / Fertozéses keratitisek diagnosztikája és kezelése.

We summarize up-to-date diagnostic and treatment of infectious keratitis using literature data and some clinical examples. In the clinical practice, most commonly bacterial, herpetic, mycotic and acanthamoeba keratitis occur. Beside slitlamp examination, for diagnostic purpose, we analyse corneal sensitivity, perform in vivo confocal microscopy, polymerase-chain-reaction (PCR), in vitro culture and histological examination of the corneal sample. As conservative treatment we use primarily topical moxifloxacin or cephasolin with fortified tobramycin or gentamycin in bacterial, topical antiviral gel (in some cases in combination with systemic antiviral treatment) in part in combination with topical corticosteroids in herpetic, voriconasole or amphotericin-B in mycotic, and topical-triple-therapy (diamidine, biguanid and antibiotics) in acanthamoeba keratitis. In case of early diagnosis and initiation of topical therapy, most cases of infectious keratitis recover successfully. However, beside conservative treatment, penetrating keratoplasty, amniotic membrane transplantation and crosslinking therapy may be necessary. Crosslinking is solely contraindicated in herpetic keratitis. Orv Hetil. 2017; 158(31): 1203-1212.

[Disorders of the extracellular matrix in epithelial-stromal and stromal corneal dystrophies]. / Az extracelluláris mátrix rendellenességei epithelialis-stromalis és stromalis cornealis dystrophiákban.

The human cornea is rich in extracellular matrix. The stroma constitutes the main thickness of the cornea, which consists of collagens and proteoglycans mainly. The epithelial-stromal and stromal dystrophies of the cornea are either autosomal dominant or recessive inherited disorders, which are unrelated to inflammation or trauma. The diseases can manifest in each layer of the cornea, but in most cases the corneal stroma is affected. Generally, they develop in childhood or young adulthood but the diagnosis is only possible when clinical signs (epithelial erosions, decreased visual acuity, photophobia) develop. The different protein aggregates (hyaline, amyloid, crystalline) deposited in the corneal layers result in mild or advanced corneal opacity and loss of the corneal transparency due to disorganisation of the extracellular matrix. In some of the corneal dystrophies the keratane sulphate proteoglycan looses its function which results in a loss of the regular interfibrillar spacing. Due to the severe corneal opacity patients may need corneal transplantation. Orv. Hetil., 2016, 157(33), 1299-1303.

[The corneal wound healing and the extracellular matrix]. / A cornealis sebgyógyulás és az extracelluláris mátrix.

The cornea is the first refractive element of the eye. The transparency of the cornea results from the regularly arranged collagen fibrils, forming lamellar structure and the leucin rich proteoglycans, which make interactions between the fibrils. The adult cornea consists mainly of fibril-forming collagens. The cornea has less amount of fibril associated and non-fibrillar collagens. The main proteoglycans of the cornea are keratan-sulfate proteoglycans and it also contains dermatan-sulfate proteoglycans. Disorders of the proteoglycan synthesis lead to the disruption of the unique pattern and result in thicker collagen fibrils. The abnormal structure of the extracellular matrix can generate corneal disorders and the loss of corneal transparency. Furthermore, proteoglycans and collagens have an important role in wound healing. In injury the keratocytes produce higher amounts of collagens and proteoglycans mediated by growth factors. Depending on the ratio of the cells and growth factors the extracellular matrix returns to normal or corneal scar tissue develops.

Repeatability data and agreement of keratometry with the VERION system compared to the IOLMaster.

PURPOSE: To analyze the repeatability of keratometric and white-to-white (WTW) distance measurements with the VERION Measurement Module (Alcon Laboratories, Inc., Fort Worth, TX) and to compare the measured data to the results of the IOLMaster (Carl Zeiss Meditec, Jena, Germany). METHODS: Three images were captured with the VERION and the flattest and steepest keratometric data, the astigmatism axis, and the WTW distance were recorded. Subsequently, the axial length, the keratometric data with axis, and the WTW distance were measured with an IOLMaster. The repeatability data of the keratometric value of the VERION System, converted to cross cylinder J0 and J45 vector components, were analyzed. The agreement data for keratometry obtained by the VERION System and the differences regarding keratometric data and WTW distance compared to IOLMaster were calculated. RESULTS: The measurements were conducted in 50 eyes of 50 healthy volunteers (median age: 50.32 years, range: 19.34 to 85.3 years). The flattest and the steepest keratometric data, the diopter of astigmatism, the J0 and J45 vector components, and WTW distance did not differ significantly between devices (P > .05). Intraclass correlation coefficients (range: 0.863 to 0.994) and Cronbach's alpha values (range: 0.950 to 0.998) were high for all parameters measured by the VERION System. CONCLUSIONS: The VERION System has high repeatability and agreement with the IOLMaster, making it suitable as an alternative tool in clinical practice.

Analysis of surgically induced astigmatism on the posterior surface of the cornea.

PURPOSE: To measure surgically induced astigmatism (SIA) on the posterior surface of the cornea using Scheimpflug-based keratometry on eyes with with-the-rule astigmatism. METHODS: Repeated Scheimpflug-based keratometry was obtained preoperatively and a mean of 8.65 weeks postoperatively following superior clear corneal incisions. Differences in the keratometric values and SIA were determined on the anterior and posterior surfaces separately and the data were analyzed. RESULTS: The study included 88 eyes of 88 patients (age range: 46.4 to 87.5 years), with the steepest total corneal meridian between 75° and 105°. Preoperatively, the magnitude of the anterior and posterior corneal astigmatism was 0.74 ± 0.44 and 0.29 ± 0.14 diopters (D), respectively, which was greater than 0.5 D in 10 eyes (11.36%). The difference between preoperative and postoperative keratometric data on the posterior surface was significant, as was the difference between the preoperative and postoperative posterior astigmatism. The mean magnitude of posterior corneal SIA was 0.32 ± 0.29 D, which was 0.5 D or greater in 22 eyes (25.00%). A statistically significant correlation was observed between the diopter of the preoperatively measured posterior corneal astigmatism and the postoperative SIA on the posterior surface (r = 0.34, P = .001). The correlation was not significant between SIA on the anterior and posterior surfaces (r = 0.10, P = .36). CONCLUSIONS: SIA on the posterior surface of the cornea may have a significant role, especially in cases of toric intraocular lens implantation. Posterior corneal astigmatism and SIA may have a significant clinical impact on more precise planning of cataract surgeries.

Mosaic arthroplasty of the medial femoral condyle in horses - An experimental study.

One Arabian and 5 Hungarian half-bred horses were used to study the macroscopic and microscopic survival of autologous osteochondral grafts in the weight-bearing surface of the medial femoral condyle (MFC). Grafts were harvested from the cranial surface of the medial femoral trochlea (MFT) under arthroscopic control. Three of them were transplanted into the weight-bearing surface of the contralateral MFC using an arthrotomy approach. Three months later this transplantation procedure was repeated on the opposite stifle joints in the same animals, but at that time transplantation was performed arthroscopically. Follow-up arthroscopy was carried out 12 months after the first operations, and biopsies were taken from both the recipient and the donor sites for histological examination. During follow-up arthroscopy, the transplanted areas looked congruent and smooth. Microscopically, the characteristics of hyaline cartilage were present in 5 out of the 10 biopsies examined; however, in the other half of biopsies glycosaminoglycan (GAG) loss and change in the architecture of the transplanted cartilage was observed. In a 16-year-old horse, all grafts broke during harvesting, and thus transplantation was not performed. No radiological signs of osteoarthritic changes were detected 9 to 12 months after the operations in the donor and recipient joints. Clinically, no lameness or effusion was present three months after the transplantations.

Spirituality is associated with immune parameters and disease activity in primary Sjögren's syndrome: a cross-sectional study.

The role of spirituality in health and disease is a complex and emerging area of research. Incorporating spirituality into the bio-psycho-social model of health and disease leading to the bio-psycho-social-spiritual model provides a more comprehensive framework. In this context, chronic disorders like primary Sjögren's syndrome (pSS) are of interest due to their intricate interactions between biological, psychological, and spiritual factors. This study explored the relationship between spirituality, immune parameters, and disease activity in pSS patients. Data from 108 patients were analyzed, including self-assessed spirituality (answering to direct questions and completing the Spiritual Transcendence Scale), immunological parameters and disease activity scores. The findings revealed several associations. Individuals with spiritual attitudes or engaged in regular prayer/meditation showed lower serum levels of autoantibodies specific to pSS and lower disease activity scores. Spiritual engagement was also linked to decreased perceived skin and tracheal dryness, suggesting potential benefits for physical symptoms. These findings suggest that spirituality may play a significant role in modulating immune responses and disease activity in pSS patients. The study underscores the importance of considering spirituality as an integral part of the holistic approach to health and disease, further expanding the understanding of the interconnectedness of biological, psychological, and spiritual dimensions.

Analysis of age-dependence of the anterior and posterior cornea with scheimpflug imaging.

PURPOSE: To assess keratometric and higher-order aberrations of the anterior and posterior cornea and their age-related changes. METHODS: This study investigated one healthy eye of 227 patients (mean age: 55.15 ± 21.2 years; range: 16 to 90 years; 135 right eyes, 92 left eyes). Images were captured from each eye with Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany) using automatic mode. Keratometric, astigmatism data, and corneal higher-order aberrations were analyzed. RESULTS: With respect to laterality, no deviance was found in any of the parameters (P > .05). Mean refractive error was 0.52 ± 0.23 diopters. The level of astigmatism decreased significantly with advancing age for both the anterior and posterior corneal surfaces (P < .05). The overall root mean square of the higher-order aberration increased continuously with age (r = 0.517; P < .01), which can be explained by the combined effect of the increased in both the anterior and posterior corneal root mean square higher-order aberrations. Of the higher-order aberrations, the constant increase of the primary and secondary spherical aberration with aging (P < .01) is caused by the spherical aberration growth of the anterior surface. Apart from these, only the vertical coma aberration of the posterior surface and the vertical trefoil aberrations of both the anterior and posterior surfaces showed a significantly positive correlation with aging (P < .05). CONCLUSIONS: Corneal astigmatism showed a significant decrease with aging. Of the higher-order aberrations, primary and secondary spherical aberrations, vertical coma, and vertical trefoil significantly increase with age, whereas other higher-order aberrations show no correlation with aging.

Repeatability of ocular biomechanical data measurements with a Scheimpflug-based noncontact device on normal corneas.

PURPOSE: To analyze the repeatability of a new device measuring ocular biomechanical properties, central corneal thickness (CCT), and intraocular pressure (IOP) and to investigate these parameters and their correlations in healthy eyes. METHODS: Three consecutive measurements were performed on each eye using the CorVis ST device (Oculus Optikgeräte, Inc., Wetzler, Germany). Ten specific parameters, CCT, and IOP were measured. Biometric data were recorded with IOLMaster (Carl Zeiss Meditec, Jena, Germany). RESULTS: This study comprised 75 eyes of 75 healthy volunteers (mean age: 61.24 ± 15.72 years). Mean IOP was 15.02 ± 2.90 mm Hg and mean CCT was 556.33 ± 33.13 µm. Intraclass correlation coefficient (ICC) was 0.865 for IOP and 0.970 for CCT, and coefficient of variation was 0.069 for IOP and 0.008 for CCT. ICC was 0.758 for maximum amplitude at highest concavity and 0.784 for first applanation time, and less than 0.6 for all other parameters. The device-specific data showed no significant relationship with age and axial length. Flattest and steepest keratometric values and IOP showed a significant correlation with the 10 device-specific parameters. CONCLUSIONS: The CorVis ST showed high repeatability for only IOP and pachymetric values. Single measurements are not reliable for the 10 device-specific parameters. The device allows for conducting clinical examinations and screening for surgeries altering ocular biomechanical properties with some form of averaging of multiple measurements.

Effect of contact lens wear on the release of tear mediators in keratoconus.

OBJECTIVES: The release of different cytokines and mediators in tears of patients with keratoconus (KC) wearing contact lenses (CLs) may contribute to the pathology of KC. METHODS: Cohort study was established in patients with KC wearing rigid gas permeable (RGP) CL (group I), patients with ametropia wearing silicone hydrogel (Si-Hi) CL (group II) and ametropic patients wearing RGP CL (group III). RESULTS: Our findings indicate that before CL wear, the release of epidermal growth factor (EGF) and tissue-type plasminogen activator (t-PA) was attenuated, whereas matrix metalloproteinase (MMP)-9, interleukin (IL)-6, chemokine (C-C motif) ligand 5 (CCL5), IL-13, and plasminogen activator inhibitor (PAI)-1 were enhanced in KC compared with ametropes. An increasing linear trend over time was found for MMP-9, EGF, and CXCL8 in KC and MMP-9, MMP-13, IL-6, and CXCL8 in group III. Significant differences were observed in the linear trend over time between groups I and III for MMP-13 and tissue inhibitor of metalloproteinases (TIMP)-1; between groups I and II for MMP-9 and CXCL8; and between groups III and II for MMP-9, CXCL8, and MMP-13. In KC, the release of MMP-9 at week 6 and nerve growth factor (NGF) at 10 min was higher, but NGF at week 2 was lower than that in group II. The release of MMP-13 and NGF at week 2 and 6 were lower in the KC group as compared with group III, and similarly, with IL-6 and CXCL8 at week 2 and PAI at all time points. CONCLUSIONS: Contact lens wear can influence the levels and dynamics of various mediators in the tears of patients with KC that might have an impact on the progression of the disease.

[Contact lens-related keratitis]. / A kontaktlencse-viselés következtében kialakuló keratitisekrol.

Nowadays, keratitis, corneal infection due to wearing contact lens means an increasingly serious problem. Neglected cases may lead to corneal damage that can cause blindness in cases of otherwise healthy eyes. Early diagnosis based on the clinical picture and the typical patient history is an important way of prevention. Prophylaxis is substantial to avoid bacterial and viral infection that is highly essential in this group of diseases. Teaching contact lens wearers the proper contact lens care, storage, sterility, and hygiene regulations is of great importance. In case of corneal inflammation early accurate diagnosis supported by microbiological culture from contact lenses, storage boxes or cornea is very useful. Thereafter, targeted drug therapy or in therapy-resistant cases surgical treatment may even be necessary in order to sustain suitable visual acuity.

A clinical feasibility study to evaluate the safety and efficacy of PEOT/PBT implants for human donor site filling during mosaicplasty.

UNLABELLED: Mosaicplasty has become a well-accepted treatment modality for articular cartilage lesions in the knee. Postoperative bleeding remains potentially concerning. This study evaluates the porous poly(ethylene oxide)terephthalate/poly(butylene terephthalate) (PEOT/PBT) implants used for donor site filling. Empty donor sites were the controls. After 9 months, MRI, macroscopical and histological analysis were carried out. Treated defects did not cause postoperative bleeding. No adverse events or inflammatory response was observed. PEOT/PBT implants were well integrated. Empty controls occasionally showed protrusion of repair tissue at the defect margins. Surface stiffness was minimally improved compared to controls. Existing polymer fragments indicated considerable biodegradation. Histological evaluation of the filled donor sites revealed congruent fibrocartilaginous surface repair with proteoglycan-rich domains and subchondral cancellous bone formation with interspersed fibrous tissue in all implanted sites. The PEOT/PBT implants successfully reduce donor site morbidity and postoperative bleeding after mosaicplasty. LEVEL OF EVIDENCE: II.

[Allergic and immunopathological diseases of the ocular surface]. / A szemfelszín allergiás és immunpatológiai betegségei.

Allergic and immunopathological diseases of the ocular surface are inflammations that can occur with mild to severe symptoms that cause visual impairment. Allergic inflammations mainly affect the conjunctiva, causing acute and/or chronic conjunctivitis. Several forms are distinguished: seasonal allergic conjunctivitis, vernal conjunctivitis, atopic keratoconjunctivitis, contact allergy, giant papillary conjunctivitis. The most common is the seasonal form, which is linked to seasons. Allergic ocular surface processes require local treatment with artificial tears, anti-allergic eye drops. If complications occur, topical corticosteroid and cyclosporin treatment may be used. Immunopathological inflammations of the ocular surface are associated with systemic diseases. Keratoconjunctivitis sicca, although occurring in the absence of systemic disease, is a common companion of Sjögren's syndrome and collagen diseases. Ocular pemphigoid belongs to the group of mucous membrane pemphigoids. After the initial conjunctivitis symptoms, subconjunctival fibrosis begins, leading to the development of sym- and ankyloblepharon. In the final stage, the ocular surface is covered by scar tissue (ocular cicatricial pemphigoid) which practically results in loss of vision. Peripheral ulcerative keratitis is usually associated with collagen vascular disease, rheumatoid arthritis. A 3-4 mm long, curved infiltration starting near the limbus becomes ulcerated and then perforates, on which the iris may prolapse. First, systemic treatment is required, which is an interdisciplinary task. Topical corticosteroid and cyclosporine eye drops may be administered. In the case of corneal perforation, amniotic membrane transplantation and/or keratoplasty may be performed. Orv Hetil. 2023; 164(43): 1686-1692.

[Corneal transplantation at the beginning of the 21th century]. / Szaruhártya-átültetés a 21. század elején.

Corneal transplantation (keratoplasty) is necessary when various disorders result in corneal opacities with severe visual loss that cannot be treated conservatively, or the regular structure and curvature of the cornea is distorted, and its function is lost. Among human transplantation, keratoplasty is the most successful surgical procedure. In recent decades, penetrating keratoplasties have been increasingly replaced by lamellar techniques, where only the abnormal layer of the cornea is transplanted. The anterior form is deep anterior lamellar keratoplasty (DALK), recommended mainly for keratoconus. The main forms of posterior lamellar keratoplasty are Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK). The indications are bullous keratopathy after cataract surgery with endothelial destruction and Fuchs endothelial dystrophy. Lamellar keratoplasty has several advantages over penetrating surgery. Postoperative visual acuity is better, wound healing, patient rehabilitation are faster and the course of any immune rejection is milder and can be better managed. Orv Hetil. 2023; 164(28): 1087-1093.

Fibrillin-2, tenascin-C, matrilin-2, and matrilin-4 are strongly expressed in the epithelium of human granular and lattice type I corneal dystrophies.

PURPOSE: To determine the extracellular matrix proteins involved in the formation of human granular and lattice type I corneal stromal dystrophies, the expression patterns of fibrillin-2, tenascin-C, matrilin-2, and matrilin-4 were compared in human corneal stromal dystrophy samples. METHODS: Ten cases of granular dystrophy, 7 cases of lattice dystrophy, and 6 normal corneal buttons collected during corneal transplantation were examined for their expression patterns of fibrillin-2, tenascin-C, matrilin-2, and matrilin-4 by immunohistochemistry. RESULTS: Highly elevated fibrillin-2, tenascin-C, matrilin-2, and matrilin-4 were observed in the epithelial layer of both granular and lattice type I dystrophies. Fibrillin-2, tenascin-C, and matrilin-4 in the granular dystrophy and all antibodies in the lattice dystrophy showed statistically significant staining in the corneal stroma (p<0.05). Interestingly, fibrillin-2, matrilin-2, and matrilin-4 stained significantly in amyloid plaques of lattice type 1 dystrophy. CONCLUSIONS: Fibrillin-2, tenascin-C, matrilin-2, and matrilin-4 may be markers of the pathogenesis of either granular or lattice type I corneal dystrophy, as revealed by immunohistochemical analysis. Each molecule seems to be involved in the regeneration and reorganization of the corneal matrix in granular and lattice type I dystrophies.

Comparison of intraocular lens power prediction using immersion ultrasound and optical biometry with and without formula optimization.

PURPOSE: Comparison of postoperative refraction results using ultrasound biometry with closed immersion shell and optical biometry. PATIENTS AND METHOD: Three hundred and sixty-four eyes of 306 patients (age: 70.6 ± 12.8 years) underwent cataract surgery where intraocular lenses calculated by SRK/T formula were implanted. In 159 cases immersion ultrasonic biometry, in 205 eyes optical biometry was used. Differences between predicted and actual postoperative refractions were calculated both prior to and after optimization with the SRK/T formula, after which we analysed the similar data in the case of Holladay, Haigis, and Hoffer-Q formulas. Mean absolute error (MAE) and the percentage rate of patients within ±0.5 and ±1.0 D difference in the predicted error were calculated with these four formulas. RESULTS: MAE was 0.5-0.7 D in cases of both methods with SRK/T, Holladay, and Hoffer-Q formula, but higher with Haigis formula. With no optimization, 60-65 % of the patients were under 0.5 D error in the immersion group (except for Haigis formula). Using the optical method, this value was slightly higher (62-67 %), however, in this case, Haigis formula also did not perform so well (45 %). Refraction results significantly improved with Holladay, Hoffer-Q, and Haigis formulas in both groups. The rate of patients under 0.5 D error increased to 65 % by the immersion technique, and up to 80 % by the optical one. CONCLUSIONS: According to our results, optical biometry offers only slightly better outcomes compared to those of immersion shell with no optimized formulas. However, in case of new generation formulas with both methods, the optimization of IOL-constants give significantly better results.

Osteochondral allograft transplantation from a living donor.

Treatment of extended and massive osteochondral defects is a real challenge for an orthopaedic practice. Osteochondral allograft transplantation is a possible solution for such lesions. Transplantation of osteochondral allografts has undergone extensive experimental and limited clinical study during recent decades. Graft availability, sizing, technical issues, and viral transmission represent the most problematic points. Because interest in this technique is gaining, more and more countries face the problem of a lack of tissue banks where fresh osteochondral allografts are available. We investigated the advantages of the so-called living donor transplantation of the grafts under programmed surgical conditions. We demonstrate a technique that allows the transplantation of osteochondral allografts without the need for a tissue bank. The radiologic and histologic results regarding the quality of the transplanted cartilage are presented.