Ultrastructure of neurovascular changes in human diabetic retinopathy

The previous concept regarding diabetic retinopathy assigned a primary role to hyperglycemia-induced microvascular alterations, while neuronal and glial abnormalities were considered to be secondary to either ischemia or exudation. The aim of this study was to reveal the potential role of neuronal and glial cells in initial and advanced alterations of the retinopathy in human type 2 diabetes. Electron microscopy and histochemical studies were performed on 38 surgically removed human eyes (28 obtained from diabetic patients and 10 from non-diabetic patients). Morphometric analysis of basement membrane material and lipids was performed. An accumulation of metabolic by-products was found in the capillary wall with aging: this aspect was significantly more pronounced in diabetics. Müller glial cells were found to contribute to alterations of the capillary wall and to occlusion, as well as to the development of proliferative retinopathy and cystoid degeneration of the retina. Our results showed morphological evidence regarding the role of neuronal and glial cells in the pathology of diabetic retinopathy, prior and in addition to microangiopathy. These morphological findings support a neurovascular pathogenesis at the origin of diabetic retinopathy, thus the current treatment approach should be completed by neuroprotective measures

A comparison of macular structure imaged by optical coherence tomography in preterm and full-term children

PURPOSE: Macular anatomic abnormalities were examined by optical coherence tomography (OCT) imaging in premature children and compared with those of full-term children. METHODS: In a prospective case-control study, premature patients 7 to 14 years of age were divided into three groups (group I, laser-treated retinopathy of prematurity [ROP]; group II, spontaneously regressed ROP; group III, no ROP), and age-matched children (group IV). All the eligible 74 eyes had normal-appearing posterior pole, myopia < or =3 D, and best corrected visual acuity 1.0. When both eyes of a subject were eligible for the study, one eye was randomly selected (10 eyes of 10 children in each group). Retinal thicknesses of the macula measured by OCT3 were compared. The correlation between central foveal thickness and prematurity (gestational age at birth < or = 30 weeks; birth weight < or = 1250 g) or ROP was determined. RESULTS: The mean foveal and central retinal thicknesses decreased significantly in group I (laser-treated ROP) and group IV (term birth). Significant differences in central retinal thickness were found between the premature groups and full-term children (Mann-Whitney U test). The cutoff point of central retinal thickness, determined by receiver operating characteristic curve was 209 microm. The general estimating equation model statistics found a significant effect of ROP severity (P = 0.003), P value for the category of prematurity was 0.063. CONCLUSIONS: The central retinal thickness was significantly higher in the preterm groups than in the full-term group. This subtle macular modification may be related mainly to ROP. Prematurity had only a marginally significant role

Mutation Detection in Patients with Retinal Dystrophies Using Targeted Next Generation Sequencing

Retinal dystrophies (RD) constitute a group of blinding diseases that are characterized by clinical variability and pronounced genetic heterogeneity. The different nonsyndromic and syndromic forms of RD can be attributed to mutations in more than 200 genes. Consequently, next generation sequencing (NGS) technologies are among the most promising approaches to identify mutations in RD. We screened a large cohort of patients comprising 89 independent cases and families with various subforms of RD applying different NGS platforms. While mutation screening in 50 cases was performed using a RD gene capture panel, 47 cases were analyzed using whole exome sequencing. One family was analyzed using whole genome sequencing. A detection rate of 61% was achieved including mutations in 34 known and two novel RD genes. A total of 69 distinct mutations were identified, including 39 novel mutations. Notably, genetic findings in several families were not consistent with the initial clinical diagnosis. Clinical reassessment resulted in refinement of the clinical diagnosis in some of these families and confirmed the broad clinical spectrum associated with mutations in RD genes

Histopathological and pancytokeratin-, E-cadherin-based immunohistochemical investigation of the canine prolapsed third eyelid gland

SUMMARY Background: Prolapse of the third eyelid gland is the most common primary disorder of the canine nictitating membrane. Objectives: The aim of the present histopathological, immunohistochemical study was to describe microscopic pathomorphological lesions of the parenchyma, and the interstitium of the surgically removed prolapsed canine third eyelid glands (TEG), compared to the normal ones. Materials and Methods: Five intact, and 26 surgically removed prolapsed TEG samples were separated and conserved in buffered, 8% formalin for 24 hours at room temperature, embedded in paraffin wax and further processed for sectioning (3–4 µm) and immunohistochemistry (antibodies: anti-pancytokeratin, and anti-E-cadherine). Results and Discussion: Histopathological lesions included (n = 26): 53.84% (n = 14) acute purulent parenchymatous adenitis, which was accompanied by with acute purulent ductal inflammation in 9 cases; 34.61% (n = 9) subacute-chronic lymphocytic interstitial adenitis, coupled with acinar degeneration and necrosis in 8 cases; 30.77% (n = 8) interstitial fibrosis; 3.85% (n = 1) adenoma. During the immunohistochemical investigations, the inflamed, degenerated TEG showed weaker or even loss of the pancytokeratin-, and E-cadherine-expression

A szemészeti génterápiák fejlődése : Pontszerző, továbbképző közlemény tesztkérdésekkel

A Szemészet hasábjain 2014-ben megjelent Genetika a szemészetben c. továbbképző közlemény folytatásaként jelen munkánkban szeretnénk összefoglalni a szemészeti genetika területén azóta elért biotechnológiai, diagnosztikus és terápiás eredményeket. Az elmúlt évek legnagyobb áttörése egyértelműen az RPE65-gén hibái okozta Leber congenitalis amaurosis (LCA) és retinitis pigmentosa (RP) kezelésére kifejlesztett voretigene-neparvovec törzskönyvezése és bevezetése a klinikai gyakorlatba. 2022 júliusában a Semmelweis Egyetem Szemészeti Klinikája akkreditációt kapott, mint Szemészeti Génterápiás Centrum és azóta megtörtént az első 10 kezelés LCA-ban szenvedő betegekben. A már bevezetett kezelés mellett számos más génterápiás kutatás, fejlesztés történik mind öröklődő, mind szerzett betegségek esetében. A terápiával párhuzamosan a genetikai diagnosztika is jelentős fejlődésen ment keresztül az elmúlt években: a módszerek jelentősen gyorsabbak és költséghatékonyabbak, ezáltal minden eddiginél szélesebb körben elérhetőek lettek. Kutatási együttműködések keretében hazánkban az elmúlt másfél évben több, mint 500 magyar öröklődő retinadisztrófiás beteg genotipizálása történt meg

Leber congenital amaurosis: first genotyped Hungarian patients and report of 2 novel mutations in the CRB1 and CEP290 genes.

PURPOSE: To introduce the first Hungarian patients with genetically defined Leber congenital amaurosis (LCA) and to report 2 novel mutations. METHODS: Seven otherwise healthy patients (4-29 years, 5 male and 2 female) who had an onset of severe visual impairment before age 2 years were investigated. The diagnosis was established in all individuals by medical history, funduscopy, and full-field electroretinogram (ERG). Ocular examination included visual acuity testing, digital fundus photography, and in 6 patients retinal imaging with optical coherence tomography (OCT). Arrayed primer extension microarray screening was performed in all probands. In 2 patients, further Sanger sequencing and targeted next-generation sequencing revealed the second disease allele. RESULTS: A cone-rod type LCA was revealed in 4 patients and a rod-cone type disease in 3 patients. Five patients presented with maculopathy. Optical coherence tomography (OCT) imaging showed diffuse retinal thickening in 3 probands with severe macular atrophy in one. Full-field ERGs were undetectable or residual in all patients. Genetic screening revealed AIPL1, CRB1, and CEP290 gene-related pathology in 6 patients; in 1 proband, no mutation was found. Three homozygous and 3 compound heterozygous mutations were identified. Two novel variants were detected: c.2536G>T (p.G846X) in the CRB1 gene and c.4929delA (p.Lys1643fsX2) in the CEP290 gene. CONCLUSIONS: Genetic subtypes identified are among the most common ones in LCA; the phenotypes are consistent with those reported previously. Both novel mutations are predicted to result in a premature translation termination. The phenotype related to the novel CRB1 mutation results in severe atrophic maculopathy