bluuebunny/crossref_metadata_2025 huggingface dataset:
Hyperlipidemia induces Meibomian gland dysfunction
Authors: Li Wei , Bu Jinghua , Wu Yang , Yu Jingwen , He Xin , He Hui , He Hui , Guo Yuli , Zhang Mingjie , Liu Zuguo
Published: December 2019

Purpose

To investigate the pathological changes of meibomian gland (MG) and ocular surface tissues in Apolipoprotein E knockout (ApoE‐/‐) mice and wild type mice fed with high fat diet, and to illustrate the effect of hyperlipidemia on meibomian gland function.

Methods

The ocular surface of ApoE‐/‐ male mice and age and sex matched wild type mice fed with standard diet or high fat diet was observed under slit lamp microscope. MG tissue sections underwent H&E staining, Oil Red O staining, TUNEL assay, and immuno‐fluorescence staining for K10, Fabp5, Ki67, K6a, p63, PPAR‐g, NF‐kB p65, p‐NF‐kB p65, caspase 3, caspase 8, and immune‐histochemical staining for CD45. Real‐time RT‐PCR and Western blot was performed to detect above mentioned gene expression in MG tissues. Lipid metabolism related genes expression in MG were also detected by real‐time RT‐PCR.

Results

Eyelid thickening, keratinization and corneal neovascularization occurred in ApoE‐/‐ mice at the age of 5 months, and the changes were more obvious at 7 months. H&E staining showed hypertrophy of the meibomian gland acinus, and Oil red O staining showed accumulation of lipid in MG acinus of ApoE‐/‐ mice. Both K10 and Fabp5 expression were increased, while Ki67, K6a, p63 were decreased in ApoE‐/‐ mice compared to the wild type mice. Cytoplasmic and nuclear expression of PPAR‐g was decreased, NF‐kB p65, p‐NF‐kB p65, caspase 3, and caspase 8 expression was higher in the ApoE‐/‐ mice compared to the wild type mice. TUNEL assay showed more positive cells in the meibomian gland acinus of ApoE‐/‐ mice. CD45 positive cell infiltration increased from 5 months to 7 months in ApoE‐/‐ mice. Lipid metabolism related genes such as FFAR1, PAR3, ACSL3, and LIPC were decreased in ApoE‐/‐ mice compared to the wild type mice. Wild type mice fed with high fat diet showed similar pathological changes as ApoE‐/‐ mice.

Conclusion

Hyperlipidemia could induce abnormal meibomian gland acinar cell proliferation, differentiation, and lipid metabolism. Hyperlipidemia condition may be an important pathogenesis factor of meibomian gland dysfunction.
P2RY12 expression at different time‐points in a mouse model of experimental glaucoma
Authors: Fernández‐Albarral José A. , Ramírez Ana I. , de Hoz Rosa , Salobrar‐García Elena , López‐Cuenca Inés , Liscastro Ester , Valiente‐Soriano Francisco J. , Vidal‐Sanz Manuel , Ramírez José M. , Salazar Juan J.
Published: December 2019

Purpose

Down‐regulation of P2RY12 after injury constitutes a sensitive marker for the transition from resting to activate microglia. P2RY12 is expressed by microglia but not by monocytes, infiltrating macrophages or dendritic cells, thus can used to identify resident microglia. Thus, the aims of the study is to determine the P2RY12 expression on retinal Iba‐1+ cells after unilateral laser‐induced ocular hypertension (OHT) in OHT‐eyes and their contralateral eyes, at different time points (1, 3, 5, 8 and 15 days) and in the different retinal layers such as outer segments (OS), outer plexiform layer (OPL), inner plexiform layer (IPL) and the complex nerve fiber layer‐ganglion cell layer (NFL‐GCL)), after unilateral laser‐induced ocular hypertension (ULOHT) in OHT‐eyes and their contralateral eyes.

Methods

Albino Swiss mice were divided into two groups, naïve and lasered. In this last group OHT, eyes and their contralateral eyes were studied. Retinal whole‐mounts were double‐immunostained with Iba1 and P2RY12 antibodies.

Results

In naïve eyes, Iba‐1+ cells expressed P2RY12, with the exception of perivascular microglia and dendritic‐like Iba‐1+ cells in all retinal layers analyzed. In OHT eyes, at 24 h and 15 d after laser induction, most Iba‐1+ cells showed high P2RY12 expression in the OS, OPL, IPL and NFL‐GCL, except some rounded cells in the OS and NFL‐GCL and very few ramified cells in the IPL and NFL‐GCL. At intermediate times (3 d and 5 d), P2RY12 expression was dramatically lower than at 1d in all retinal layers. Expression increased weakly at 8 d, reaching values similar to those in naïve eyes at 15 d. In contralateral eyes, as in naïve ones, Iba‐1+ cells were intensely labelled with anti‐P2RY12 in all retinal layers at all‐time points analyzed.

Conclusion

Most of Iba‐1+ cells in the OHT eyes and contralateral eyes at the different time‐points were microglia, as demonstrated by their P2RY12 expression. P2RY12 expression is reduced after microglial activation indicating that 3 d and 5 d were the point‐times in which the microglial activation was maximal.

Acknowledgement

This work was supported by Ophthalmological Network OFTARED (RD12‐0034/0002 and RD12/0034/0014. Prevención, Detección Precoz y Tratamiento de la Patología Ocular Prevalente Degenerativa y Crónica), the Institute of Health of Carlos III of the Spanish Ministry of Economy; PN I+D+i 2008‐2011; ISCIII, General Subdirection of Networks and Cooperative Research Centers; by the FEDER European program. Grants to J.A. Fernández‐Albarral are currently supported by a Predoctoral Fellowship (FPU) from the Spanish Ministry of Science, Innovation and University.
Diabetic retinopathy outcomes in patients undergoing pancreatic transplants in West London
Authors: Szymanska Maja , Yap Timothy , Normando Eduardo , Cordeiro Francesca
Published: December 2019

Purpose

To quantify the proportion of diabetic patients undergoing pancreas transplant in West London and their service use. To characterise their long‐ and short‐term retinopathy grading and visual function outcomes following surgery, the incidence of ophthalmic interventions and factors associated with DR progression.

Methods

Retrospective study of diabetic patients undergoing pancreatic transplant in West London between 2001–2018. Key outcomes examined included visual acuity (VA) and retinopathy grading, as well as service use and subsequent ophthalmic treatments. Patients with failed pancreatic transplants acted as a comparison group.

Results

Data from 56 patients were analysed including 51 patients with Type 1 and 5 with Type 2 diabetes mellitus. Mean age (±SD) at the time of transplant was 42 ±9  years with mean duration of disease 24 ±7 years. Data from 56 patients were analysed including 51 patients with Type 1 and 5 with Type 2 diabetes mellitus. Among them, 63% of patients were found under diabetic eye screening programme and 11% under ophthalmic secondary care at the time of transplant. At the time of transplant, 7% of eyes had no DR, 13% had background retinopathy, 13% had non‐proliferative and 67% had stable or treated proliferative retinopathy. During short‐term follow‐up (3 years), 17% of eyes developed DR progression. Amongst patients who underwent a successful transplant, there was no significant change in mean VA before and after the intervention. Long‐term follow‐up (6.6 years) revealed no significant difference in mean VA between patients with successful and failed transplants.

Conclusion

This study shows that pancreatic transplantation does not guarantee prevention of DR progression. Close monitoring of these patients both in primary and secondary care is advised, however, favourable long‐term visual outcomes are possible with appropriate and timely treatment.
The hypocritical optic disc in long term visual loss
Authors: Krastel Hermann , Gass Achim , Erwemi Marwa , Kahlert Christian , Jonas Jost B.
Published: December 2019

Purpose

To demonstrate diagnostic pitfalls due to apparently unsuspicious optic discs

Methods

Retrospective observations present case histories with unsuspicious disc appearance despite severe affections, as documented by imaging incl. MRI and OCT, and analysis of visual function incl. visual fields, color vision, and visual electrodiagnostic.

Results

A meningioma of the apical orbit produced a mild degree of congestion which, with respect to the appearance of the disc and the RNFL thickness, balanced for the loss of nerve fibers.

At 64 years of age, a male patient began to suffer from bilateral visual loss and binocular central scotomas without detectable reason by clinical examination and history. Minute chiasmal MRI findings led to a suspicion of LHON which was confirmed by molecular genetics.

Following an accident with forehead blunt trauma, asymmetrical binocular visual loss was noticed. Visual fields showed a junction scotoma. By CT and MRI, no lesions were detected except minute optic nerve sheath findings pre ‐ chiasmatically. As functional impairment increased, LHON was proven by molecular genetics.

After a polytrauma incl. skull fractures, moderate visual loss and glare sensitivity was found without any explaining lesion. Primarily regarded as minor sequence of the accident, minute temporal disc pallor eventually led to ocular electrodiagnostic, which revealed a cone dystrophy.

Conclusion

An apparently unsuspicious disk may conceal severe optic nerve affections; a minute finding at the optic disk may point to a severe retinal affection.
Characterization of cataract patients’ lens epithelial cells by using synchrotron based FTIR
Authors: Andjelic Sofija , Kreuzer Martin , Dučić Tanja , Hawlina Marko
Published: December 2019

Purpose

The mechanisms involved in the process of cataract formation are not yet fully understood. Lens epithelial cells (LECs) are important for the maintenance of lens transparency as they control energy production, antioxidative mechanisms and biochemical transport for the whole lens. The purpose of this study is to characterize LECs compounds of two different cataract types, nuclear (N) and cortical (C), by using the high resolution synchrotron radiation‐based Fourier Transform Infrared (SR‐FTIR) microspectroscopy.

Methods

The anterior lens capsule (basement membrane and associated LECs) were obtained from cataract surgery and prepared by desiccation for FTIR. Measurements were set to achieve single cell resolution. Data obtained by SR‐FTIR have been analysed by comparing all spectra of N type and C type LECs. The average spectra of each group have been calculated and principal component analysis (PCA) has been performed.

Results

The first component of the PCA in Amide I area of spectra showed the most prominent contribution at 1625 cm‐1 which is associated with beta sheet organisation in protein aggregates in N cataract type. In the C type we found proteins organized more in the turn and loops conformation (~1670 cm‐1). The markers of oxidative stress: ratios of the asymmetric vibration CH2 and CH3, as well as C=O/lipids showed an increase in C cataract type LECs that pointed out to an increase in lipid peroxidation in this type of LECs. The region corresponds to the P=O asymmetric bands indicate possible difference in protein phosphorylation in C and N types LECs.

Conclusions

Here we evaluated the proteins conformation changes, as well as lipids and phosphates bands in LECs of two different cataract types. The oxidative stress and the lipids peroxidation were more pronounced in C type, while protein aggregation is associated with N type. These spectral changes can be assigned to specific biochemical processes occur in two different cataract types LECs.
A case of choroidal osteoma in a 5‐year‐old child
Authors: Karlsruher Gisela , Montes Paula , Marco Sara , López Isabel , Dolores Díaz María , Boned Ana , Ramiro Patricia , Javier Ascaso Francisco
Published: December 2019

Purpose

To report a case of choroidal osteoma (CO) in a 5‐year‐old boy.

Methods

Case report

Results

A 5‐year‐old child presented with decreased vision in both eyes. His best‐corrected visual acuity (BCVA) was 20/50 in the right eye (OD) and 20/100 in the left eye (OS). The anterior segment was normal in both eyes. Cycloplegic refraction was +2.50 ‐2.25 x 10 in the OD and +3.25 ‐2.50 x 180 in the OS. Funduscopy of the OS revealed a large subretinal, yellowish lesion in the juxta‐papillary area. B‐scan ultrasonography of the OS revealed a dense echogenic plaque with acoustic shadowing. The axial CT scan also showed a calcified lesion in the posterior pole. Optical coherence tomography (OCT) was normal at the fovea but revealed subretinal fluid (SRF) at the superior temporal vascular arcade. Spectacle correction was prescribed and alternating part‐time occlusion was performed. The patient was asked to come for regular follow‐up. Six months later his BCVA was 20/25 in both eyes, no variations of the mass were noted and the SRF disappeared.

Conclusions

OC is a rare, benign ossifying tumor. It is typically found in healthy young women, mostly unilateral, in the posterior pole of the eye, near the optic disc. It is relatively rare in children. OC must be differentiated mainly from amelanotic choroidal melanoma, choroidal nevus, choroidal hemangioma, choroidal metastasis, sclerochoroidal calcification and posterior scleritis. In children it can pose a serious diagnostic challenge as it can mimic other lesions at posterior pole, such us retinoblastoma, retinochoroidal coloboma, and toxoplasmic retinochoroiditis. Asymptomatic or stable CO can be observed. For choroidal neovascular membranes photodynamic therapy and laser treatment have been used in the past. More recently, anti‐VEGF treatments have been employed with success.
The link between central retinal thickness and retinal nerve fibre layer thickness in patients with retinitis pigmentosa
Authors: Friesacher Anna , Valmaggia Christophe , Todorova Margarita
Published: December 2019

Purpose

Linking central retinal thickness (CRT) with retinal nerve fibre layer thickness (RNFL) in retinitis pigmentosa (RP) patients.

Methods

37 patients with typical RP and 19 age‐matched controls (p = 0.352), who underwent Spectral Domain Optical Coherent Tomography of the macula and optic disc, were included. The RP group was divided in two subgroups: with clinical appearance of macular oedema (ME‐RP; 30 eyes) and without it (no‐ME; 44 eyes). Macula OCT data were averaged in three zones [Z1 (0°–3°), Z2 (3°–8°) & Z3 (8°–15°)] and were evaluated in relation to the RNFL thickness.

Results

The subgroup ME‐RP differed significantly from the subgroup no‐ME‐RP by increased CRT (Z1) and increased averaged RNFL thickness, and when compared to controls (p ≤ 0.002). No‐ME‐RP group hat reduced CRT thickness (Z1‐3; p ≤ 0.018), compared to controls and ME‐RP, whereas the RNFL thickness in the no‐ME‐RP group was reduced only compared to ME‐RP group (p < 0.001). A significant positive interaction was found between the CRT (Z1 & Z2) and RNFL thickness within ME‐RP (p ≤ 0.010).

Conclusion

The presence of macular oedema correlated well with the increase in RNFL thickness in RP patients. Such association provide evidence for a common underlying mechanism of retinal degeneration. Simultaneous monitoring of CRT and RNFL thickness may help in the future to evaluate the progression of the disease and the efficacy of treatments for ME in RP.
Pseudoexfoliation glaucoma – Do genes or environment matter more?
Authors: Greene Alison , Eivers Sarah , Dervan Edward , O'Brien Colm , Wallace Deborah
Published: December 2019

Purpose

Lysyl oxidase like 1 (LOXL1) catalyzes collagen and elastin crosslinking. Single nucleotide polymorphisms (SNPs) within LOXL1 are associated with pseudoexfoliation (PXF) syndrome and PXF glaucoma (PXFG). These SNPs are present in 50%–80% of the general population, suggesting environmental factors also play a role in disease development. Our aim was to investigate LOXL1 levels in Human Tenons Fibroblasts (HTFs) and aqueous humour (AqH) from PXF, PXFG and cataract controls (CAT) and to establish if there was an association with genotype, epigenetic regulation (methylation) or environmental factors (hypoxia, oxidative stress, UV exposure and caffeine intake).

Methods

Patients with PXF, PXFG and CAT were recruited and genotyped. LOXL1 expression was measured by qPCR and Western Blot and LOXL1 activity by ELISA. CAT HTFs were cultured in hypoxic (1% O2) and oxidative stress conditions (200 μm hydrogen peroxide). Epigenetic analysis was determined by global DNA methylation and qPCR of methylation‐associated enzymes. Environmental factors were recorded in a RedCap™ database.

Results

Increased high‐risk LOXL1 gene haplotypes were observed in PXFG compared with CAT. LOXL1 expression and activity was decreased in PXFG HTFs vresus CAT (p < 0.01). This was replicated in CAT HTFs cultured under hypoxic (p < 0.05) and oxidative stress conditions (p < 0.01). Global DNA methylation and DNMT1 and 3A expression was increased in PXFG compared to CAT (p < 0.05). DNMT inhibition using 5‐azacytidine restored LOXL1 expression in PXFG (p < 0.05). Outdoor occupation was associated with PXFG. PXFG patients with the high‐risk (G‐G) haplotype had higher rates of trabeculectomy and numbers of IOP lowering drugs.

Conclusions

A combination of genetic, epigenetic and environmental factors contributes to LOXL1 expression in PXFG. LOXL1 genotyping may offer a means of screening for risk of disease progression and epigenetic modifiers such as 5‐azacytidine may represent a future therapeutic target for PXFG.
Different rate of retinal degenerations in mice with two distinct mutations in the Mitf gene
Authors: Eysteinsson Thor , Jónasdóttir Ingunn , García‐Llorca Andrea , Björg Gudmundsdóttir Thorunn , Ögmundsdóttir Margrét Helga , Steingrímsson Eiríkur
Published: December 2019

Purpose

The microphthalmia‐associated transcription factor (Mitf) gene is crucial for development of the retinal pigment epithelium (RPE) and photoreceptors. Loss of function mutations in this gene can cause ocular hypopigmentation, microphthalmia and blindness. Mice heterozygous for the Mitfmi‐wh/+ mutation have been used as a model for Waardenburg and Tietz syndromes in humans. The compound heterozygote Mitfmi‐wh/Mitfmi has two different mutant alleles in the Mitf gene each of which have quite severe effects on the phenotype. The purpose of this study was to examine changes over time in retinal function and structure in these mice, between 1 and 5 months of age, to elucidate the rate of progression of the retinal degenerations.

Methods

B6‐Mitfmi‐wh/+ and B6‐Mitfmi‐wh/Mitfmi mice were examined and compared to C5BL/6J mice as control. Mice were anesthetized by an intraperitoneal injection of 40 mg/kg‐1 Ketamine and 4 mg/kg‐1 Xylazine. Fundus and optical coherence tomography (OCT) images were obtained with a Micron IV. Flash electroretinography (ERG) from mice with a corneal electrode was used to determine retinal function.

Results

Fundus images from all mutant mice show hypopigmentation at 1 month, with large non‐pigmented areas forming at later stages. Mitfmi‐wh/+ mice are either blind or not at 1 month, with the ERG normal in amplitude in some animals and absent in others. The Mitfmi‐wh/+ mice with ERG responses at 1 month show slow retinal degeneration, with reduced responses at 5 months. Mitfmi‐wh/Mitfmi mice show either abnormal ERG responses at 1 month, or a flat ERG. The ERG responses in some of the Mitfmi‐wh/Mitfmi mice decrease with time, and at 4 months is flat. OCT images reveal that retinal layers in animals with flat ERG are thinner than in mice showing reduced ERG, but abnormally thin in both.

Conclusions

We conclude that Mitfmi‐wh/Mitfmi mutant mice show evidence of fast retinal degeneration. The Mitfmi‐wh/+ mutant mice are either blind at 1 month or show evidence of slow degeneration. Mice with these Mitf mutations may serve as models of retinal degenerations progressing at different rates, due to mutations in a gene expressed in the RPE.
The correlations between posterior scleral profile and autonomic dysfunction in normal tension glaucoma
Authors: Young Shin Da , Kee Park Chan
Published: December 2019

Purpose

To investigate the association between autonomic dysfunction and posterior scleral profile in normal tension glaucoma.

Design

Observational, cross‐sectional study.

Participants

Two hundred eight NTG patients.

Method

Complete ophthalmic examination was performed in all patients including heart rate variability to evaluate autonomic dysfunction. Posterior scleral profile, which was identified by the disc tilt ratio, disc torsion, disc foveo angle and peripapapillary area(PPA) to disc ratio was measured from disc photographs. Patients were classified into the two groups according to the standard deviation value of the qualified normal to normal intervals(SDNN) of the heart‐rate‐variability assessment. Group 1 consisted of patients within the one standard deviation from the average of the SDNN measurements. And Group 2 consisted of patients outside one standard deviation from the average of the SDNN measurements, indicating that they had too higher or too lower SDNN of HRV. So Group 2 having deviated value was thought to have abnormality in HRV. Two groups were compared. Logistic regression analysis was used to determine the relationship between posterior scleral profile and abnormality of heart rate variability.

Main outcome and measure

Association between posterior scleral profile(axial length, tilt ratio, torsion ratio, disc foveo angle, PPA to disc ratio) and autonomic dysfunction.

Results

The mean value of SDNN in 208 NTG patients was 33.71 and the standard deviation was 18.16. Group1 had a SDNN values between 15.55 and 51.87 and Group 2 had a SDNN value less than 15.55 or greater than 51.87. Among 208 NTG eyes, 164 (78.8%) were group 1 and 44 (21.2%) were group 2. Axial length was significantly longer in Group 2 than Group 1 (p = 0.008). Degree of disc torsion were significantily higher in Group 2 than group 1 (p < 0.001). Although just short of statistical significance (p = 0.058), disc tilt ratio was higher in group 2. Torsion degree was the only factor related to heart rate variability in both univariate (p < 0.001) and multivariate (p = 0.008) logistic regression analyses.

Conclusion

Our study results showed that the dysfunction of an autonomic control is associated with posterior scleral profile such like disc tilt ratio, torsion degree, axial length.
Individual characters affected by cataract in the riverside population of the Tapajós River, in Pará
Authors: Caramel Lais Raphaelli , Simão Giovanna Oncala , Czezacki Alexandre Scramin , Mont’Alvão Vanessa Giffoni Braga , França Jhenifer Nataly Moura , Gobbo Luísa da Cunha , Reis Bruna Albertini , Ricioli Isabella Soares , Olavarria Gustavo de Campos , de Souza Marianne Benedicto , Beckedorff Otto Albuquerque , Pizzato Rebecca de Souza , Carmo Thiago José Delfraro , Succi Fabiana Moreira Passos , Minussi Luíza Abreu , Abreu Elvira Barbosa
Published: December 2019

Purpose

The study search a prevalence Cataracts profile in the Riverside Population of the Tapajós River, in Pará. In view of this disease, it is the largest cause of reversible blindness in the world, accountable of 47.8% of the cases and of great social relevance because it impacts the quality of life.

Methods

A prospective, observational, analytical, cross‐sectional, ecological study based on the review of medical records in the voluntary project Barco de Saúde São Leopoldo Mandic. The cataract cases were classified according to the LOCSIII system.

Results

Of these, 56.6% are males and 43.39% are females. The proportion between each age group was: 0.62% (10–19 years); 1.88% (30–39 years); 16.98% (40–49 years); 32.7% (50–59 years); 24.5% (60–69 years); 19.49% (70–79 years) and, 3.77% (80–89 years). The prevalence of pseudophakia among the other diagnoses was 2.64%. The mean visual acuity with correction in each age group was: 20/30 (10–19 years); 20/25 (30–39 years); 20/25 (40–49 years); 20/50 (50–59 years); 20/60 (60–69 years); 20/110 (70–79 years) and 20/250 (80–89 years).

Conclusions

The incidence of cataract in north of Brazil is high, when compared, for example, with the USA, where the overall prevalence is only 8.6%. The number of pseudophakia is low (2.64%). The beginning of appearance is untimely and the proportion of cases is higher than the resto of the country.
Pharmacokinetics of angiotensin‐receptor blocker in cyclodextrin nanoparticle eye drops in rabbits
Authors: Kallab Martin , Schützenberger Kornelia , Hommer Nikolaus , Jasmin Schäfer Bhavapriya , Tan Aimin , Jansook Phatsawee , Stefansson Einar , Garhöfer Gerhard
Published: December 2019

Purpose

Cyclodextrin nanoparticles form water‐soluble complexes with lipophilic and poorly water‐soluble drugs and thus can greatly improve drug transport from the ocular surface to the posterior eye segment. The aim of the current study was to evaluate the ocular pharmacokinetics and biodistribution of two newly developed □‐cyclodextrin based angiotensin receptor antagonist formulations for topical administration: cyclodextrin‐Irbesartan 1.5% and cyclodextrin‐Candesartan 0.15%.

Methods

59 rabbits were included in the study to receive one of the two study drugs. For each drug group, single and multiple dose pharmacokinetics were performed in a randomized fashion: Single dose rabbits were euthanized 0.5, 1.5, 3 or 6 hours post eye drop administration, whereas multiple dose animals were dosed for 5 days twice daily. Pharmacokinetic parameters including maximal drug concentration (Cmax) and time of maximal drug concentrations (Tmax) for single dosing and mean concentrations for multiple dosing were calculated for aqueous humor (AH) and retina/choroid (RT). Analysis was done using LC‐MS/MS.

Results

Topical administration of the study drugs was well tolerated. Single dose Irbesartan eye drop administration led to a RT Cmax of 251 ng/g ± 143 ng/g at 0.5 hours whereas in the AH a Cmax of 121 ng/g ± 69 ng/g was reached at 3 hours post instillation. For single dose Candesartan eye drops, RT Cmax was 63 ng/g ± 39 ng/g at 0.5 hours after application. AH reached a Cmax of 30 ng/g ± 14 ng/g at the 3 hours time point. For multiple dosing mean RT concentration reached 338 ng/g ± 124 ng/g for Irbesartan and 36 ng/g ± 10 ng/g for Candesartan, whereas mean AH concentrations were 231 ng/g ± 68 ng/g and 70 ng/g ± 22 ng/g, respectively.

Conclusions

The present data confirm that cyclodextrin based Candesartan and Irbesartan eye drops deliver drugs to the posterior pole of the eye in biologically relevant concentrations.
Increased lipofuscin accumulation associated with disturbed mitophagy in NRF2/PGC1α double knockout mice
Authors: Sridevi Gurubaran Iswariyaraja
Published: December 2019

Purpose

Oxidative stress and mitochondrial damage are long protruded cause of detrimental aggregation diseases including age‐related macular degeneration. We recently reported elevated levels of oxidative stress markers, damaged mitochondria, accumulated lipofuscin and drusen like structures in retinal pigment epithelial cells (RPE) of NRF2/PGC1α double knockout mice model.

Methods

Immunostained RPE samples from one‐year old NRF2/PGC1α and age matched wild type mice were used for confocal microscopy analysis.

Results

Lipofuscin accumulation associated with deficiency of mitophagy in RPE cells of NRF2/PGC1α double knockout mice. Immunohistochemical analysis revealed high staining levels of autophagosome marker, microtubule‐associated proteins 1A/1B light chain 3B (LC3B) and mitophagy markers, PTEN‐induced putative kinase 1 (PINK1) and E3 ubiquitin ligase (PARKIN) on damaged mitochondria. Moreover, high levels of late autolysosomal fusion protein Rab7 accumulated in the peri‐nuclear space of RPE cells with increasing incidental colocalization of lipofuscin.

Conclusion

Our study reveals that fusion of lysosomes and autophagosomes occurs, but mitophagy flux is disturbed in lipofuscin loaded RPE cells of NRF2/PGC1α double knockout mice.
OCT‐angiography: Mydriatic phenylephrine and tropicamide do not influence retinal microvasculature in the macula and peripapillary region
Authors: Hohberger Bettina , Müller Meike , Hosari Sami , Mardin Christian
Published: December 2019

Purpose

Optical Coherence Tomography Angiography (OCT‐A) enables visualization of retinal microcirculation. As a potential influence of mydriatic eye drops on retinal vessels was proposed, purpose of the study was to investigate the influence of phenylephrine and tropicamide on macula and peripapillary microcirculation measured with en face OCT‐A.

Methods

30 eyes of 30 healthy persons were measured by en face OCT‐A (Heidelberg OCT II Spectralis, Germany). Scans of the macula (subdivided: 12 sectors) and peripapillary region (subdivided: 4 sectors) were performed before and 30 min after local application of phenylephrine 5% and tropicamide 0.5%. Vessel density (VD) was quantified in three retinochoroidal layers (superficial vascular plexus (SVP), deep capillary plexus (DCP), intermediate capillary plexus (ICP)). Data analysis was done by the Erlangen‐Angio‐Tool.

Results

(1) Mean VD was 33.03 ± 3.1 (SVP), 23.53 ± 2.9 (ICP) and 25.48 ± 4.2 (DCP) before and 33.15 ± 2.9 (SVP), 23.74 ± 2.9 (ICP) and 25.82 ± 4.0 (DCP) during mydriasis. (2) Sectorial analysis showed a range of 30.63 ± 2.9–34.45 ± 2.9 (before) and 31.04 ± 2.9–34.34 ± 2.7 (during mydriasis) in SVP, 22.61 ± 2.9–24.93 ± 3.2 (before) and 22.75 ± 2.5–25.20 ± 3.0 (during mydriasis) in ICP and 24.56 ± 4.7–26.45 ± 3.4 (before) and 25.00 ± 4.1–27.07 ± 3.5 (during mydriasis) in DCP. (3) No differences between overall and sectorial VD before and after mydriatic eyedrops were observed (p>0.05). (4) Peripapillary region showed a mean VD of 31.82 ± 3.8 before and 31.59 ± 4.3 during mydriasis. Sectorial analysis of VD yielded a range of 31.04 ± 4.1–32.65 ± 3.8 (before) and 30.98 ± 4.4–31.89 ± 4.1 (during mydriasis). (5) Peripapillary VD was not statistically different during mydriasis compared to without (p>0.05).

Conclusion

Phenylephrine 5% and tropicamide 0.5% do not influence retinal microcirculation in macula and peripapillary region. Thus, OCT‐A can be done in mydriasis in order to enhance imaging process and quality of the scans.
Targeted genome sequencing of negative and positive human papillomavirus induced conjunctival carcinomas
Authors: Ramberg Ingvild , Toft Peter , Jensen David , von Buchwald Christian , Cilius Nielsen Finn , Funding Mikkel , Heegaard Steffen
Published: December 2019

Purpose

To perform a comprehensive targeted genome sequencing of premalignant and malignant conjunctival squamous cell carcinomas in order to elucidate the genetic background of these tumours.

Methods

Due to the scant knowledge of the mutational landscape in conjunctival carcinomas, we performed next‐generation sequencing of 509 genes commonly affected in human cancers. We sequenced a total of 110 tumours; 31 invasive carcinomas, 55 preinvasive and 24 coupled recurrent tumours. All cases were investigated for presence of human papillomavirus (HPV) by p16 immunohistochemistry, messenger RNA in situ hybridisation and HPV DNA PCR, and HPV positive tumours were genotyped by sequencing.

Results

21.4 % of the tumours were HPV positive. High‐risk HPV16 was the most commonly detected genotype (70%). There was an average of 9 mutations identified in each tumour. C to T substitutions at pyrimidine sites leading to missense mutations were the most common type of mutations. HPV negative tumours frequently harboured mutations in FGFR2, IGF1R, and EP400, whereas HPV positive tumours most frequently harboured mutations in the FOS, AKT2 and mTOR genes.

Conclusions

Ultraviolet radiation (UV)‐induced signature mutations were found in both HPV positive and HPV negative tumours. Different genes were affected in tumours harbouring high‐risk HPV positive tumours compared to HPV negative tumours.
The ability of eye tracking perimetry to detect glaucoma
Authors: Tatham Andrew , McClean Pam , Murray Ian , McTrusty Alice , Harry Brash , Brian Fleck , Minns Robert
Published: December 2019

Purpose

To examine the diagnostic ability of saccadic vector optokinetic perimetry (SVOP), a new eye tracking perimeter, by assessing its capacity to differentiate healthy and glaucomatous participants, and to compare performance to standard automated perimetry (SAP).

Methods

A prospective case‐control study including patients with glaucoma and healthy volunteers recruited from the glaucoma clinic at a university hospital and from the Scottish Health Research Register (SHARE). Participants underwent a comprehensive ophthalmic examination and performed SAP and SVOP in both eyes with the order of testing randomised.

Results

61 eyes of 31 participants with glaucoma and 47 eyes of 24 healthy participants were included in the study. Average SAP mean deviation (MD) in glaucomatous eyes was ‐8.72 ± 7.37 dB, with average SAP and SVOP sensitivities of 23.28 ± 0.89 dB and 22.1 ± 4.25 dB respectively. There was strong correlation between average SAP and SVOP sensitivities (r = 0.951 , P<0.001). On average, SAP sensitivity was 1.16 ± 1.43 dB higher than SVOP sensitivity, with 95% limits of agreement of ‐1.64 to 3.96 dB. SVOP average sensitivity had excellent ability to differentiate healthy and glaucomatous eyes with an AUC of 0.90 (95% CI 0.84 to 0.96), which was not significantly different to the performance of SAP average sensitivity (AUC = 0.92, 95% CI .0.86 to 0.97, P = 0.60) (Figure 6). SVOP had 85.2% sensitivity for 80% specificity, compared to 86.9% sensitivity for 80% specificity for SAP.

Conclusions

The results of this study suggest that eye tracking perimetry using SVOP could offer a feasible alternative to SAP for detection of glaucoma. Overall, there was good agreement between differential light sensitivity values measured using SVOP and those measured using SAP, and average SVOP and SAP sensitivities had similarly good ability to differentiate glaucomatous and healthy eyes.
The Influence of stereopsis on ability to perform simulated cataract surgery
Authors: Tatham Andrew , Dutton James , Watkins Alice , Dhillon Baljean
Published: December 2019

Background

The purpose of this study was to determine whether impaired or absent stereopsis affects ability to perform simulated microsurgical tasks.

Methods

A prospective randomized cross‐over study including 12 medical students. Visual acuity and stereoacuity were measured for all subjects. A band pass filter was placed over the non‐dominant eye to reduce stereoacuity to 150 seconds of an arc (partial stereopsis) or the non‐dominant eye was completely occluded (absent stereopsis). Participants completed a computerized surgical simulator task three times with the order of testing randomized (normal stereopsis, absent stereopsis and partial stereopsis). The task involved forceps to grasp and position objects in the anterior chamber. Outcomes included area of ocular injury, time to task completion and overall score.

Results

Ocular damage area was significantly worse when stereopsis was impaired to 150 seconds of an arc (p = 0.002), and worse still when stereopsis was absent (p < 0.001 for normal versus absent stereopsis and p = 0.005 for impaired versus absent stereopsis). The median ocular damage area was 3.55 mm2 (IQ range 1.21 to 5.88 mm2) with normal stereopsis, increasing to 6.10 mm2 (IQ range 3.96 to 12.47 mm2) with stereopsis reduced to 150 seconds of an arc and to 9.25 mm2 (IQ range 4.93 to 18.70 mm2) with no stereopsis. Time taken to complete the task increased and overall score decreased as stereopsis was reduced. Overall score decreased from 53% (IQ range 22.5 to 82%) under normal stereopsis to 0% (0 to 43.5%) with absent stereopsis.

Conclusion

Impaired stereopsis was associated with worse microsurgical performance which may have implications for surgical training. Absence of stereopsis resulted in worse performance than partial reduction in stereopsis.
Investigating the role of Gli1 in the development of choroidal neovascularisation
Authors: Marry Stephen , Xu Heping , Chen Mei
Published: December 2019

Uncontrolled inflammation in the retina can lead to fibrovascular membrane formation, which can cause severe structural damage to the retina thus leading to blindness. The pathogenesis of retinal fibrosis is not completely understood. Recent research has implicated the Hedgehog pathway transcription factor Gli1 in the development of fibrosis. This study aims to elucidate the role of Gli1 in the development of fibrovascular membranes in the retina utilising fluorescent reporter mice.

Gli1CreERT2 mice were crossed with ROSA26TdTomato mice to produce Tomato x Gli1 crossbreeds. 6‐7 week old Heterozygous Tom x Gli1 mice received 100 mg/kg Tamoxifen daily (I.P.) for 5 days. Mice were monitored for 80 days to determine the duration Gli1‐Tomato expression. Eyes and other organs were collected for immunofluorescent staining. Tom x Gli1 mice received 4–5 laser burns per eye to induce choroidal neovascularisation and were monitored over 21 days to assess the expression of Gli1 in the injured retina using fundus imaging and immunofluorescent staining.

Expression of Gli1‐Tomato was detected as far 80 days in the eye, predominantly in the choroid, sclera, cornea and ciliary body. Immunofluorescent staining displayed co‐expression of Gli1 with CD31+, NG2+, and Collagen 4+ blood vessels. Fundus imaging of CNV lesions displayed expression of Gli1‐tomato around the lesion. Immunostains of cryosections showed co‐expression of Gli1 with blood vessel markers in choroidal lesions.

Gli1+ cells are expressed throughout the eye, most notably with blood vessels, and may contribute to the development of choroidal lesions in CNV.
A conditional Mitf mouse model of geographic atrophy (GA)
Authors: García Llorca Andrea , Sabaté Alba , Ögmundsdóttir Margrét Helga , Larue Lionel , Gesbert Franck , Steingrímsson Eiríkur , Eysteinsson Thor
Published: December 2019

Purpose

Mice carrying different mutations in the microphthalmia‐associated transcription factor (Mitf) gene, affect the normal the retinal pigment epithelium (RPE) resulting in microphthalmia. The MitfK243R/K243R; Tyr::Cre mice have an induced conditional mutation, where Lysine 243 is mutated to Arginine, thus affecting DNA binding. The purpose of this study was to characterize eye development and function in these mutant mice. Our analysis shows retinal degeneration and slow progressive GA in the eyes of these mice.

Methods

C5BL/6J (wild type) and MitfK243R/K243R; Tyr::Cre mice of 1, 3 and 12 months old were used in this study. Fundus and optical coherence tomography (OCT) images were taken from wild type and mutant mice. Retinal function was assessed by electroretinography (ERG). RNA isolation from posterior eye cups and reverse‐transcription quantitative PCR (RT‐qPCR) were done to analyze Mitf mRNA expression.

Results

Bright field images indicate that eyes from B6‐MitfK243R; Tyr::Cre mice have alternating areas of severe hypo‐ and hyperpigmentation and vascular abnormalities. OCT images from 1 and 3 months old mutants demonstrated that some regions of the retina have the RPE, photoreceptor and neuronal layers intact, while neighboring areas show severe degeneration of these cell types. However, at one year of age the RPE, photoreceptor and outer retina layers are missing in the mutants. ERG recordings revealed that at 1 and 3 months old the mutants had significantly reduced (p < 0.05) photopic b‐wave, scotopic a‐ and b‐waves, while at 12 months old the mutant cone and rod ERG responses were flat or severely reduced compared to wild type. Gene expression analysis showed that Mitf expression was elevated in the mutants as compared to wild type, suggesting compensatory mechanisms.

Conclusions

We have found that mice with the MitfK243R conditional mutation driven by the Tyr::Cre driver may be the first mouse model of slow progressive retinal GA. This mutant shows similar characteristic as seen in human age‐related macular degeneration (AMD) and may therefore provide a model for that disease.
Activating an optogenetically engineered retina with a wearable headset in patients with retinitis pigmentosa
Authors: Chavas Joël , Boussahoul Nacer , Duport Damien , Galle Charlie , Galluppi Francesco , Blouin Laure , Burguière Pierre , Hardin Thomas , Shabestary Proshato , Gray David
Published: December 2019

Purpose

Optogenetics allows the expression of channelrhodopsins like ChrimsonR (ChR) in the retina of blind patients in order to confer light sensitivity to retinal ganglion cells (RGCs). However, ChR has a low sensitivity to light and is unlikely to be activated by ambient light. To activate ChR and to obtain a functional response from the RGCs, we developed and tested a wearable headset that delivers light stimulation to the human retina at an appropriate irradiance and wavelength.

Methods

We designed and constructed a wearable headset using electronics, optics, mechanics and software engineering. The proper range of light intensity required for the activation of ChR fused with tdTomato (ChRtdT) was tested on explanted retinas of non‐human primates (NHPs) transfected with AAV2.7m8‐ChRtdT. The ocular safety of exposure to 595 nm LED light following intravitreal injection of AAV2.7m8‐ChRdtT was assessed in rd1 mice, an established animal model for retinitis pigmentosa.

Results

Activation of ChRtdT in explanted retinas of NHPs transfected with AAV2.7m8‐ChRtdT showed that a minimum of 1015 photons/cm2/s (0.33 mW/cm2) of amber light was required to get a statistically significant electrophysiological response.

In rd1 mice transfected with AAV2.7m8‐ChRtdT, fourteen days after exposure to 595‐nm LED light for 2 hours, no light‐related findings were identified in the retina at the highest intensity tested (nominal 1.7 × 1017 photons/cm2/s).

As a result, our wearable headset provides a retinal irradiance up to 4 × 1016 photons/cm2/s for a period leading to a dose matching the one received by the retina of rd1 mouse exposed for 2 hours, a level shown to be safe for the retina.

Conclusion

Our medical device GS030‐MD was designed to send a light irradiance to the human retina both sufficient to activate ChRtdT and safe for the eye. GS030‐MD is currently being tested in combination with AAV2.7m8‐ChRtdT in the first‐in‐man PIONEER Phase I/II clinical trial.
Synthesis and application of magnetic nanoparticles (MNPs) in drug delivery to the retina
Authors: Bassetto Marco , Ajoy Moreno Daniel , Poulhes Florent , Marion Vincent , Dollfus Helene , Zelphati Olivier
Published: December 2019

Introduction

The development of an innovative drug delivery system to target, after topical administration, the retina with bioactive agents against retinal pathologies is a major challenge. Currently, the sole approach to target these tissues is through intravitreous injection, but this is not free from problematics such as severe side effects and rapid clearance of small molecules from the vitreous.

Purpose

We aim to synthesize, develop and formulate a new magnetic nanoparticle‐mediated delivery technology that shall allow achieving needle‐free, anesthesia‐free delivery of active drugs to the retina after topical administration assisted by magnetic targeting.

Methods

MNPs have been synthesized, physico‐chemically characterized and loaded with small organic drugs (valproic acid/Guanabenz).

The MNPs biocompatibility have been studied in vitro on retinal pigmented epithelium and photoreceptor cell lines and in vivo after topical administration.

The MNPs have been applied on mice under the influence of an external magnetic field to guide them towards the retina.

The in vivo histological and functional assays have been monitored to determine the biological effect of the treatment.

Results

The iron oxide‐based MNPs have spherical shape, a hydrodynamic size less than 150nm and they were not affected by the drug‐loading process. HPLC measurements demonstrate the high loading capacity of the MNPs and reproducibility of the method. Cell proliferation assays showed that MNPs are fully biocompatible.

Conclusions

MNPs combined with magnetic targeting is a promising technology for the delivery of bioactive agents to the retina after topical, needle‐free administration.
Pharmacological modulation of the VCP/ERAD/proteasome axis rescues photoreceptor degeneration in P23H rhodopsin
Authors: Sen Merve , Kutsyr Oksana , Bolz Sylvia , Chou Tsui‐Fen , Deshaies Ray , Arango Gonzalez Blanca , Ueffing Marius
Published: December 2019

Purpose

One of the most prevalent mutations in rhodopsin (Rh) causing autosomal dominant retinitis pigmentosa (adRP) RhP23H, results in its misfolding and its retention in the Endoplasmic Reticulum (ER). VCP is an ATP driven molecular checkpoint at the ER before these proteins are released from the ER towards plasma membrane. Misfolded proteins are selectively identified, retained at the ER and cleared by a process called ER‐associated degradation (ERAD). ERAD overload due to RhP23H misfolding causes cell death. As several pathways regulating protein homeostasis are associated with ERAD, we tested their specific impact on photoreceptor (PR) degeneration through pharmacological inhibition.

Methods

Organotypic cultures from RhP23H retinas of transgenic rats at PN9 cultured for 6 days and treated with different concentrations of pathway specific inhibitors: NMS‐873 interferes with quality control mechanisms by VCP inhibition; the proteasome inhibitor Bortezomib (BO) suppresses proteasomal degradation; the mannosidase inhibitor Kifunensine (KIF) blocks processing of glycoproteins, and Geldanamycin (GA) inhibits the protein‐folding mechanism in the ER. PR cell survival was assessed by counting cell rows and measuring the percentage of TUNEL‐positive cells. Rh distribution was checked using a specific antibody.

Results

VCP inhibitor caused strong and dose‐dependent protection at 5μM. Proteasome inhibition by BO significantly reduced the number of dying cells at 10μM. The number of PR cell rows in the ONL was increased by both. Only VCP inhibitor corrected aberrant inner segment distribution of Rh shifting it to physiological outer segment (OS). In contrary, KIF and GA accelerated PR cell degeneration.

Conclusions

Modulation of the VCP/ERAD/proteasome axis by inhibiting VCP and proteasome rescues PR cells in RhP23H. Inhibition of VCP activity establishes proper transport of Rh to the OS. These results strongly suggest that the VCP/ERAD/proteasome axis acts as a critical checkpoint in PR homeostasis.
The effect of age on penetrating keratoplasty indications
Authors: Karahan Mine
Published: December 2019

Purpose

The aim of this study was to evaluate the indications of penetrating keratoplasty (PKP) according to age groups.

Methods

Between September 2017 and April 2019, 120 patients who underwent PKP in our clinic were divided into five groups according to their age ranges. 1st group; 11‐25, 2nd group; 26‐40, 3rd group; 41‐55, 4th group; 56‐70 and 5th group; 71‐90 years old. The frequency of PKP indications were evaluated according to the age groups.

Results

The records of 120 patients with age range of 11‐89 (60.4 ± 21.9), 61 of whom were female and 59 were male were retrospectively reviewed. 67 of the eyes made PKP were right eyes and 53 of them were left eyes. There was no difference between the groups in terms of laterality. PKP indications were as follows: 14 (12%) keratoconus, 60 (50%) keratitis / post‐traumatic corneal scar, 11 (9%) corneal dystrophy, 7 (6%) corneal ulceration / perforation, 28 (23%) aphakic / pseudophakic bullous keratopathy. According to age groups, the most common PKP indications were as follows, respectively: keratoconus in the 1st group (n=8, 53%), keratitis / post‐traumatic corneal scar in the 2nd group (n=6, 50%), keratitis / post‐traumatic corneal scar in the 3rd group (n=9, 56%), aphakic / pseudophakic bullous keratopathy in the 4th group (n=7, 32%) and keratitis / post‐traumatic corneal scar in the 5th group (n= 35, 63%).

Conclusions

In our study, the most common indication for PKP was keratitis / post‐traumatic corneal scar. When evaluated according to age groups the difference between groups was not significant. On the other hand, it was observed that keratoconus was the most common PKP indication in the 1st group and the difference was statistically significant when compared with other age groups. Therapeutic reasons for PKP after 25 years of age are prominent due to regional and climatic differences.