bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual field loss patterns in dominant and recessive optic atrophy based on OPA1 archetypes
Authors: Cascavilla Maria Lucia , Coutinho Catarina , Battista Marco , Zanchetta Ferdinando , Galzignato Alice , Lari Giorgio , Albertini Stefano , Brotto Luigi , Nucci Paolo , Fioresi Rita , Bandello Francesco , Barboni Piero
Published: January 2024

Aims/Purpose: Identification and quantification of visual field loss patterns of dominant optic atrophy forms (ACO2 and AFG3L2 mutations) and recessive optic atrophy form (WFS1 mutation, Wolfram Syndrome, WS) based on machine learning‐obtained archetypes for OPA1‐Dominant Optic Atrophy (DOA).

Methods: Five patients affected by hereditary optic neuropathies carrying ACO2 gene mutations, 5 with AFG3L2 mutations, and 20 with WFS1 mutations were enrolled. Visual field (VF) tests performed by SITA standard 30–2 or 24–2 Humphrey VF analyzer (Carl Zeiss Meditec, Dublin, CA, USA) were collected for these patients. The VFs of these rare mutations (30% WFS1, 10% ACO2 and 3% AFG3L2 [1]) were decomposed and quantified according to the archetypes (AT) obtained in the unsupervised machine learning model developed for the OPA1 mutation.

Results: The archetype analysis (AA)‐model developed for the DOA‐OPA1 mutation is composed of twelve ATs, with the central, the ceco‐central, and the para‐central as the most significant ones. For WS patients, the VF‐decomposition was mostly made up of ATs resembling more severe abnormalities, while for the ACO2 and AFG3L2‐affected patients the most important ATs were similar to the OPA1 cases.

Conclusions: The developed AA‐model based on OPA1‐DOA affected patients enabled the decomposition of VFs of more rare optic atrophy mutations. The association of weights to the different ATs for patient‐specific VFs showed to be a possible option to identify and quantify the most important patterns of visual field loss in such particular cases of autosomal dominant or recessive optic neuropathies. A pattern‐specific visual field loss might strengthen the differential diagnosis between OPA1 and other mutations and support future clinical and therapeutic trials.

References

1. Rocatcher A, Desquiret‐Dumas V, Charif M, et al. The top 10 most frequently involved genes in hereditary optic neuropathies in 2186 probands. Brain 2023; 146(2): 455–460. doi: 10.1093/brain/awac395
Peripapillary retinal layer thickness is associated with retinal oxygen saturation in newly diagnosed patients with multiple sclerosis
Authors: Nes Dragana , Berg‐Hansen Pål , de Rodez Benavent Sigrid A. , Høgestøl Einar A. , Beyer Mona K. , Rinker Daniel A. , Veiby Nina , Karabeg Mia , Petrovski Beáta Éva , Celius Elisabeth G. , Harbo Hanne F. , Petrovski Goran
Published: January 2024

Aims/Purpose: Structural and physiological abnormalities have been reported in the retina of people with multiple sclerosis (pwMS). We aimed to investigate whether change in the peripapillary retinal nerve fibre layer (RNFL) thickness is associated with difference in retinal oxygen (O2) saturation in newly diagnosed pwMS.

Methods: Retinal oxygen saturation was measured using imaging by spectrophotometric non‐invasive retinal oximeter. RNFL thickness was acquired by RS‐3000 NIDEK OCT. Twenty‐five newly diagnosed pwMS were included. The measurements were performed primarily on the right eye; 25 healthy individuals (HCs) were age‐ and gender‐ matched with the pwMS. Arterio‐venular difference (A‐V diff) was calculated from the mean arteriolar and venular O2 saturation values based on measurements obtained from all vessels. Data were analysed by Spearman correlation.

Results: There was a significant positive correlation between RNFL and A‐V diff in pwMS (p = 0.0014; rho = 0.4949), and no significant difference in the O2 saturation in retinal venules and arterioles in pwMS (mean: 60.0% and 93.7%; p = 0.5980) compared to HCs (mean: 59.3% and 91.5%; p = 0.8934), respectively.

Conclusions: Our findings indicate that early in MS, changes in RNFL and A‐V diff are detectable, before patients develop any apparent/severe disease. We recommend inclusion of the peripapillary RNFL and A‐V diff in MS monitoring and research.
Changes in colour perception in Alzheimer's disease continuum
Authors: Elvira‐Hurtado Lorena , López‐Cuenca Inés , De Hoz Rosa , Salas Mario , Sanchez‐Puebla Lidia , Matamoros José A. , Fernández‐Albarral José A. , Salazar Juan Jose , Mestú Fernando , Gil Pedro , Ramirez Jose Manuel , Salobrar‐Garcia Elena
Published: January 2024

Aims/Purpose: The progression of Alzheimer's disease (AD) manifests from a preclinical stage, characterized by asymptomatic pathological alterations, to an advanced stage of AD accompanied by cognitive impairment. The aim of this study was to explore visual function along the entire AD continuum, from individuals with a high genetic predisposition to those in the moderate phase of the disease.

Methods: All participants underwent a visual examination and had to be visually healthy to be included. The study contained five groups: controls (n = 53), individuals with a positive family history of AD (HF+) (n = 13), mild cognitive impairment (MCI) (n = 23), mild AD (n = 25) and moderate AD (n = 21). The study analysed the results of errors in colour perception.

Results: A significant increase in the total number of errors was observed between the control group and the moderate AD group. And also when comparing the FH+ group with the MCI group, the mild AD group and the moderate AD group. Significant differences were found on the tritan axis between the control group and the mild AD group, as well as in the moderate AD group. Significant differences were observed between the FH+ group and the mild AD group, as well as in the moderate AD group. A significant increase in the number of errors on the deutan axis was observed between the control group and both the mild and moderate AD groups. In addition, a statistically significant increase was observed when comparing the FH+ group with the moderate AD group. The test correlated with the MMSE score and also showed good predictive value when memory impairment was present.

Conclusions: Understanding the importance of changes in colour perception in AD continuum can aid in the early detection and treatment of AD, potentially improving patient outcomes and facilitating targeted interventions.
Natural course of clinically isolated optic neuritis: implications for trial design
Authors: Küchlin Sebastian , Ihorst Gabriele , Heinrich Sven , Marquez Pablo , Albrecht Philipp , Hug Martin , Diem Ricarda , Lagrèze Wolf
Published: January 2024

Aims/Purpose: To characterize disease‐induced changes in the first six months after acute optic neuritis and to aid the design of future neuroprotection trials.

Methods: Treatment‐independent analysis of the TONE trial cohort (NCT01962571), including 103 patients with acute optic neuritis and baseline high contrast visual acuity <0.5 dec. We analysed study visits at baseline and weeks 1, 4, 16 and 26 with mixed effects linear piece‐wise models to describe the dynamics of low contrast letter acuity, contrast sensitivity, visual fields, visually evoked potentials and macular and peripapillary retinal layer thicknesses. Sample size estimates are based on a two‐sided t‐test with α=0.05, power 80%, and treatment effects equal to 50% of the mean diseased induced change.

Results: After baseline visual loss, there was improvement of visual function with thinning of inner and swelling of outer retinal layers. Clinical trials could reduce their required size by more than half when using macular ganglion cell and inner plexiform layer thinning (33 patients/group) over peripapillary retinal nerve fibre layer thinning (79/group) as the primary outcome. Similarly, trials of functional neuroprotection could reduce their size by more than 40% when employing the inter‐eye delta of 2.5% low‐contrast letter acuity (109/group) over the affected eye's value alone (189/group) as their outcome. The respective associations to vision‐related quality of life (NEI‐VFQ overall score) were similar (Pearson's |r| = 0.08 vs. 0.15 and 0.38 vs. 0.39). Because inner retinal layer thicknesses remained stable after four months but functional improvements continued up to month six, trials should follow up accordingly.

Conclusions: The negative results of the TONE trial make its participants one of the best‐characterized and largest cohorts of acute optic neuritis. Our data show that future trials may benefit from substantial efficiency gains.
Archetypal analysis for dominant optic atrophy visual field loss
Authors: Coutinho Catarina , Zanchetta Ferdinando , Galzignato Alice , Battista Marco , Lari Giorgio , Albertini Stefano , Borrelli Enrico , Savini Giacomo , Cascavilla Maria Lucia , Bandello Francesco , Fioresi Rita , Barboni Piero
Published: January 2024

Aims/Purpose: Identification of the characteristic visual field loss patterns of dominant optic atrophy (DOA) employing the Archetypal Analysis (AA) machine learning algorithm and further relation with patient‐specific parameters.

Methods: For 64 patients affected by molecularly confirmed DOA with OPA1 heterozygous mutation, binocular visual field (VF) tests performed by SITA standard 30–2 or 24–2 Humphrey VF analyser (Carl Zeiss Meditec, Dublin, CA, USA) were collected. For patients that had multiple VF tests, several VFs were collected to enlarge the dataset. Resorting to Python 3.8 (Anaconda) an AA model was developed to determine and quantify the DOA underlying patterns of visual loss. After a careful analysis involving different linear and non‐linear machine Learning models and algorithms, the different archetypes (AT) were related to parameters such as age and visual acuity.

Results: Considering 229 VF test, employing the AA, twelve archetypes were detected for the characterization and quantification of visual loss in DOA. Central, ceco‐central, and para‐central ATs revealed to be the most significant ones, matching the common characteristic scotomas for DOA patients, followed by quadrantanopia, altitudinal, and nasal step ATs.

Younger patients were related to less severe visual loss representative ATs, while patients with lower visual acuity were related to more severe visual loss representative ATs.

Conclusions: Archetypal analysis shows to be a potential powerful tool to support clinicians in the identification of DOA patients by identifying and quantifying visual loss patterns characteristic of this disease. Relation with other patient‐specific parameters might strengthen the differential DOA diagnosis.
Intravitreal injection of Noggin ameliorates retinal degeneration in a mouse model of retinitis pigmentosa
Authors: Fernandez‐Bueno Ivan , Font Carlos , Martin Abey , Martin Mark , Helm Courtney , Tsai E‐Jine , Xu Mei , George‐Weinstein Mindy , Bravo‐Nuevo Arturo
Published: January 2024

Purpose: To determine the therapeutic efficacy of intravitreal injections of Noggin in a rodent model of retinitis pigmentosa (RP). Noggin is expressed by Myo/Nog cells which are critical for eye morphogenesis and have been shown to be both neuroprotective and a source of contractile myofibroblasts in ocular diseases. Noggin is a bone morphogenic protein (BMP) inhibitor. BMPs play important roles in eye development but the strength of this signalling pathway must be carefully regulated. Furthermore, BMP levels increase in the central nervous system under stress and injury.

Methods: Male and female C3H/HEJ mice (n = 30) exhibiting Pde6b gene mutation, considered a model of RP, were divided into 3 experimental groups (n = 10 each). At week 2.5 post birth, mice received either a bilateral, single intravitreal injection (1 μL) of phosphate buffer saline (PBS; Control 1), mouse serum albumin (MSA; Control 2), or human recombinant Noggin (25 ng; Treatment). At weeks 3 and 5, electroretinograms (ERGs) were performed to assess retinal function, and mice were sacrificed. Then, eyes were enucleated, fixed, frozen, cryosectioned, and immunolabelled to evaluate apoptosis (TUNEL), Myo/Nog cells (BAI1), and neuroretinal thickness.

Results: Apoptosis was significantly decreased in the Noggin treated group compared to controls (PBS and MSA) at both time points. Noggin treatment also resulted in increased thickness of the neuroretina. The number of Noggin producing Myo/Nog cells was higher in the retinas of all the control groups compared to the Noggin‐injected group. ERGs showed significant improvement of the A‐ and B‐waves in Noggin injected mice when compared to control groups at 3‐ and 5‐weeks post‐birth.

Conclusions: Intravitreal injection of Noggin in a RP rodent model improved retinal function and decreased apoptosis and retinal thinning. Myo/Nog cells increase in number in response to stress and injury. The decrease in the number of Myo/Nog cells in response to Noggin treatment further supports the conclusion that this BMP inhibitor reduced tissue damage. These results suggest that inhibition of BMP signalling may be a therapeutic approach to reducing retinal degeneration in RP.
A 15 month follow‐up study characterizing the progression of retinal pathology and visual loss in CLN3 ex7/8 mice
Authors: Torsti Tommi , Toropainen Elisa , Tamminen Toni , Kauppinen Anu , Kaarniranta Kai , Forsberg Markus M.
Published: January 2024

Aims/Purpose: Juvenile form of neuronal ceroid lipofuscinosis is a is a rare neurological disease that manifests in childhood, by progressive visual dysfunction. The progression and timeline of the retinal degeneration in the eye has not been comprehensively characterized. We performed a 15‐month follow‐up study aiming to reveal the progression of retinal pathology in CLN3 ex7/8 mice modelling juvenile neuronal ceroid lipofuscinosis.

Methods: ERG, OCT, and fundus imaging was performed in CLN3 ex7/8 mice every three months at 3, 6, 9, 12 and 15 months. Scotopic electroretinography was performed with Espion ERG using silver electrodes. Mice were kept overnight in dark room before testing. Eyes were exposed to flashes of light periodically increasing in intensity (0,0001–1 Cd × s/m2). Responses to multiple flashes were averaged to obtain a single waveform at each intensity. OCT and fundus images were captured with the Phoenix MICRON® Image‐Guided OCT.

Results: In scotopic ERG responses lower amplitudes of a‐ and b‐wave were observed CLN3 ex7/8 mice compared to WT mice at all time points. A progressive, almost 2‐fold decrease of b‐wave amplitude (at 0.03 Cd × s/m2) was seen in CLN3 ex7/8 mice between 3 and 15 months, compared to WT. Most notable decline of b‐wave amplitude (~70% of the decrease, at 0.03 Cd × s/m2) was seen from age of 6 to 12 months. A‐wave amplitudes in CLN3 ex7/8 mice were consistently lower but not progressively reduced when compared to WT mice. The accumulation of drusen was observed in the fundus images of CLN3 ex7/8 mice. In OCT images we observed signs of retinal outer segment atrophy. These effects were not observed in WT animals to the same degree.

Conclusions: We observed age‐dependent retinal outer segment atrophy with drusen‐like deposit accumulation visually with OCT and fundus imaging in CLN3 ex7/8 mice, and the results correlate well with ERG results. According to the progressive decline of b‐wave amplitude, the decrease of vision seems to be most prominent between the ages of 6 and 12 months. This result indicates progressive loss of function in inner retinal neurons. The present results reveal the progression of the pathology in CLN3 ex7/8 mice as well as the time window for testing novel disease‐modifying interventions in CLN3 ex7/8 mice.
A pilot study for decellularizing human and porcine cornea for future use in corneal regeneration
Authors: Josifovska Natasha , Niemi Essi M. , Scholz Hanne , Petrovski Goran
Published: January 2024

Purpose: To effectively decellularize human and porcine corneas for future use in corneal regeneration by using an already established decellularization technique being efficient in decellularizing blood vessels.

Methods: One human and 4 porcine corneas were decellularized by using various washing steps with 3‐[(3‐cholamidopropyl) dimethylammonio]‐1‐propanesulfonate (CHAPS) detergent, Benzonase, Ethylenediaminetetraacetic acid (EDTA), 5% Dextran or 5% D‐Mannitol. The quality of the decellularization process was assessed by quantitative and qualitative measurement of DNA content, glycosaminoglycans (GAGs), immunofluorescent staining for Collagen I, V and keratocan, and Transmission Electron Microscopy (TEM) to observe the structure of the collagen fibrils was used.

Results: The decellularization process showed 99,94% and 99,52% DNA content reduction in the human and porcine corneas when using Dextran, respectively, while more DNA remained in the porcine corneas when D‐Mannitol was used. Similar pattern was observed in the preservation of GAGs, with the highest amount being found in the human cornea, and less in the porcine corneas. H&E and Immunofluorescent staining showed no presence of cell nuclei when compared to the control native corneas, while Alcian blue staining qualitatively confirmed the presence of GAGs. Collagen I, V and keratocan were still present in the decellularized corneas when compared to the native ones, while TEM microscopy further confirmed the similar patterns of the collagen fibrils in the decellularized‐, compared to the native‐ corneas.

Conclusions: This pilot study showed that our decellularization method is effective in decellularizing human and porcine corneas, with very high amount of DNA being removed from the corneas, while the GAGs were preserved to an acceptable extent, and the structure and pattern of the collagen fibrils maintained.
Monomeric C‐reactive protein exacerbates choroidal neovascularization in vivo: Implications for age‐related macular degeneration
Authors: Fernandez‐Robredo Patricia , Hernandez Maria , Romero‐Vázquez Sara , Recalde Sergio , Bezunartea Jaione , Orduña Maite Moreno , Layana Alfredo García , Adàn Alfredo , Molins Blanca
Published: January 2024

Aims/Purpose: Increased systemic levels of the acute phase reactant C‐reactive protein (CRP) have been linked to increased risk of age‐related macular degeneration (AMD). CRP undergoes conformational changes upon activation in inflammatory microenvironments between pentameric (pCRP) and monomeric forms (mCRP). CRP conformations present different phenotypes, as mCRP has more proinflammatory properties and has been shown to induce blood retinal barrier disruption in vitro. Thus, we aimed to evaluate the impact of CRP forms on choroidal neovascularization (CNV) in vivo.

Methods: pCRP and mCRP forms were intravenously (iv) or intravitreally (ivt) injected in C57BL6/J mice (n = 12) previously subjected to CNV induction by laser and compared to controls. CNV lesions were monitored by fluorescein angiography and mice were euthanized 11 days after lesion induction. CNV areas were measured in lectin stained choroidal flatmounts. To evaluate the CRP dissociation, pCRP was coupled to a fluorescent molecule before injection. After tissue extraction mCRP was detected by immunofluorescence in posterior pole flatmounts.

Results: Both pCRP and mCRP injected significantly increased CNV areas compared to control mice. Retinal severe edema was also observed close to the lesion in retinographies, and was more severe in intravitreally injected groups. Finally, pCRP was observed to dissociate into mCRP in intravitreally injected animals with pCRP.

Conclusions: We confirmed that CRP increases CNV areas and severe edema in the retina, suggesting that CRP is activated in the CNV inflammatory environment. Additionally, the pCRP form dissociates in vivo into mCRP close to CNV damaged tissue, hypothesizing that mCRP is the CRP conformation that contributes to the exacerbation of the CNV process. Further studies are needed to investigate anti‐mCRP molecules as candidates for mono‐ or anti‐VEGF combined therapy for AMD treatments.
Increased secretory autophagy in retinal pigment epithelial cells of the 5xFAD mice
Authors: Ruuth Johanna , Tamminen Toni , Toropainen Elisa , Koskela Ali , Tanila Heikki , Kaarniranta Kai
Published: January 2024

Purpose: Disturbed proteostasis and oxidative stress have a key role in Alzheimer's disease and age‐related macular degeneration pathology. Constant oxidative stress and disturbed proteostasis lead to intracellular protein aggregation and possibly the activation of secretory autophagy. In this study we assessed the oxidative stress and secretory autophagy related biomarker changes in the retinal pigment epithelium (RPE) of the 5xFAD mice model expressing abundant levels of the human beta‐amyloid.

Methods: The eyes of 3‐, 6‐ and 12‐month‐old WT (n = 5) and 5xFAD (n = 5) mice were enucleated, paraffin fixed and examined by immunomicroscopy. The paraffin sections were immunostained for beta‐amyloid and the key secretory autophagy markers Sec22b, TRIM16, galectin 8, IL‐1β, HMGB1 and ferritin. Moreover, the sections were stained for oxidative stress marker 4‐HNE and antioxidant enzyme catalase. Protein degradation related markers ubiquitin (Ub) and SQSTM1/p62 were analysed from 6‐ and 12‐months timepoints.

Results: Immunohistochemistry analysis revealed that the oxidative stress and protein degradation related markers were upregulated in the RPE of 6 and 12‐months old 5xFAD mice suggesting presence of oxidative stress and protein aggregation. TRIM16 and galectin 8 were increased in the RPE of the 6‐ and 12‐months old 5xFAD mice, while the increased expression of Sec22b was observed in 3‐ and 6‐months timepoint. IL‐1β, HMGB1 and ferritin were accumulated at the basal side of the RPE cells/Bruch's membrane in 6‐months old 5xFAD mice. The high accumulation of beta‐amyloid was detected in drusen like structures. Electrophysiological analysis revealed decreased scotopic and photopic signalling compared to WT mice.

Conclusions: 5xFAD mouse model seems to be a good model to study protein aggregation and activation of the secretory autophagy in response to degenerative retina processes.
Menopause‐induced neurodegeneration of retinal ganglion cells in a model of an acute retinal ischemia in rats
Authors: Rodak Piotr , Olakowska Edyta , Pacwa Anna , Machowicz Joanna , Smedowski Adrian
Published: January 2024

Aims/Purpose: To assess the influence of surgical menopause on the function and survival of retinal ganglion cells in a rat model of optic nerve crush.

Methods: A total of 27 rats, aged 8 weeks, were divided into two groups based on the duration between ovariectomy (OVE) and euthanasia. Subgroups consisted of OVE, OVE combined with optic nerve crush (ONC), and ONC alone. All surgical procedures were conducted under general anaesthesia. Menopause was induced through OVE, which involved the surgical removal of ovaries. ONC was performed to induce acute retinal ischemia. Retinal function was evaluated using electroretinography (ERG). Retinas were stained for β3‐tubulin, NeuN, Erα, Erβ, and Iba1. Cell loss ratios were assessed through manual counting using ImageJ software.

Results: After a two‐week menopause period, a reduction in retinal interneurons (RI) density was observed, but no significant decline was observed in retinal ganglion cell (RGC) count. The counts for NeuN were 373 ± 58 and 317 ± 55 (healthy vs. OVE, p < 0.02), and for β3‐tubulin were 197 ± 42 and 212 ± 38 (healthy vs. OVE, p > 0.05), respectively. Seven weeks after OVE, menopause affected RI but not RGC, with counts of 404 ± 49 and 378 ± 61 (healthy vs. OVE, p < 0.05), and 286 ± 32 and 287 ± 51 (healthy vs. OVE, p > 0.05) for NeuN and β3‐tubulin, respectively. Following the ONC procedure, the NeuN cell count was 345 ± 28 and 286 ± 40 (ONC and ONC + OVE, respectively, p < 0.0001), and for β3‐tubulin it was 221 ± 28 and 200 ± 37 (ONC and ONC + OVE, respectively, p < 0.05). In the preliminary analysis of ERG, a significant decrease in PhNR amplitudes was observed in the OVE group, while PhNR was severely diminished in the OVE + ONC group.

Conclusions: Deprivation of estrogens through surgical menopause leads to accelerated retinal neurodegeneration, primarily affecting retinal interneurons. The absence of estrogens increases the vulnerability of RGCs to insults, resulting in expedited RGC loss during acute retinal ischemia.
Mitophagy‐reporter Muller cell line (MQ‐MG2) as a novel platform for ocular drug discovery
Authors: Anderson Aidan , Bouzinab Kaouthar , Rudzinska Paula , Ganley Ian , Wallace Graham , Romero Jose M.
Published: January 2024

Aims/Purpose: The controlled activation of mitophagy has emerged as an exciting therapeutic angle in the treatment of ocular conditions, including diabetic retinopathy and age‐related macular degeneration. Here, we report a novel Muller cell line (MQ‐MG2) for the rapid screening of mitophagy‐activating drugs.

Methods: MQ‐MG2 were cloned from spontaneously immortalized primary Muller cells (PMCs) derived from mitophagy reporter (Mito‐QC) mice. Muller glia characteristics were assessed by immunocytochemistry, western blotting, and metabolic flux (Seahorse). The versatility of MQ‐MG2 to detect mitophagy‐activating drugs was tested via pharmacological activation (PINK1‐dependent and PINK1‐independent) and further validated in vivo using Mito‐QC mice.

Results: MQ‐MG2 were expanded over 50 passages while retaining expression of Mito‐QC reporter. MQ‐MG2 showed key phenotypic markers of Muller glia, including glutamine synthetase, glial fibrillary acidic protein, Aquaporin 4, and Interleukin‐33. At the bioenergetic level, MQ‐MG2 showed lower basal‐ and ATP‐linked respiration than PMCs, while displaying superior reserve capacity (p < 0.001). Indicative of equivalent glycolytic profiles, extracellular acidification rates (baseline and stressed) remained comparable to PMCs. Importantly, MQ‐MG2 showed excellent sensitivity to screen for mitophagy‐activating drugs, including novel small‐molecules acting through (putative) PINK1‐independent pathways. The versatility of MQ‐MG2 as a drug discovery platform was validated in vivo, where oral administration of PINK1‐independent activator (PIA‐01) amplified mitophagy at the outer retina dose‐dependently.

Conclusions: MQ‐MG2 enables rapid and reliable detection of mitophagy‐activating drugs for ocular application. This platform overcomes the limitations of primary cultures, including variability due to cellular senescence and heterogeneity, while minimizing the need for animals in drug discovery.
Drusen of the retinal pigment epithelium of the parapapillary region
Authors: Jonas Rahul , Jonas Jost , Panda‐Jonas Songhomitra , Jonas Shefali
Published: January 2024

Aims/Purpose: The description of the morphology, the occurrence and the associations of parapapillary drusen of the retinal pigment epithelium (dotRPE).

Methods: A histomorphometric analysis of enucleated human eyes using a light microscope.

Results: 83 enucleated human eyes (mean axial length 25.9 ± 3.2 mm; range 20.0–35.0 mm) were included for analysis using light microscope. The eyes with parapapillary dotRPE (29 of 83 eyes, 35%) in comparison with the other eyes had a shorter axial length with 24.0 ± 1.8 mm vs 27.0 ± 3.3 mm (p < 0 0.001). Additionally, a higher occurrence (27 of 29 vs 12 of 54 eyes, p < 0.001) and greater girth (213 ± 125 μm vs 96 ± 282 μm, p < 0.0001) of the parapapillary alpha zone. Bruch's membrane (BM) was thicker in the parapapillary beta zone (8.4 ± 2.7 μm vs 3.9 ± 2.0 μm, p < 0.001) and in the parapapillary alpha zone (6.6 ± 3.9 μm vs 4.4 ± 1.5 μm, p = 0.02). Underneath the dotRPE and in the parapapillary alpha zone the choriocapillaris appeared open, while it appeared intact in the center of the parapapillary beta zone. Although BM was thicker (p = 0.001) in alpha zone compared to beta zone, it was thicker in beta zone compared to region outside of either alpha or beta zone (p < 0.001). The thickness of BM outside of the parapapillary zone of alpha or beta was not correlated with either the occurrence of dotRPE (p = 0.47) or the axial length (p = 0.31). A basal membrane stained positive for PAS connected the RPE cells of the parapapillary dotRPE. The cell density of the RPE increased in the alpha zone compared to bordering regions (22.7 ± 7.3 cells/240 μm vs 18.3 ± 4.1 cells/240 μm, p < 0.001). Parapapillary dotRPE occurred in 69% (27 of 39) of eyes with a parapapillary alpha zone.

Conclusions:: Parapapillary dotRPE as fibrous pseudo‐metaplasia correlated with a shorter axial length, thicker BM in the alpha and the beta zone, as well as a higher prevalence and larger size of the alpha zone. This may be helpful to set apart the glaucomatous parapapillary beta zone and the myopic beta zone.
A microbial infection‐resistant 3D bioprinted material for corneal stroma regeneration
Authors: Lemonche Gerard Boix , Niemi Essi M. , Muñoz Georgina Faura , Scholz Hanne , Skerlavaj Barbara , Petrovski Goran
Published: January 2024

Aims/Purpose: To assess whether 3D bioprinted, scaffold‐immobilized antimicrobial peptides (AMPs) derivatives, BMAP27(1–18) and hLF(1–11) can inhibit microbial colonization to obtain infection‐resistant 3D bioprinted hemi‐corneas.

Methods: The research followed the tenets of the Declaration of Helsinki. 3D bioprinting was used to produce transparent nanocellulose‐ and alginate‐based 3D constructs. Functionalized 3D bioprinted scaffolds with AMPs were characterized by contact angle and transparency measurements. The antimicrobial and antifungal activity of the peptides in solution were investigated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods against Staphylococcus epidermidis ATCC 35984, S. aureus ATCC 25923, S. epidermidis ATCC 12228, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 90028. The antimicrobial activity of the AMP‐modified scaffolds was studied against P. aeruginosa and C. albicans reference strains by colony forming unit (CFU) counts, and their biocompatibility was investigated by measuring the viability of primary human/cadaver‐isolated corneal stromal‐mesenchymal stromal cells (CS‐MSCs).

Results: The original and modified peptides showed MIC (MBC) values of 1–4 (2–8) μM and 16 – >128 (32 – >128) μM, respectively, against S. epidermidis ATCC 35984, S. aureus, S. epidermidis ATCC 12228, P. aeruginosa, E. coli and C. albicans, while ncBP‐BMAP27(1–18) and ncBP‐hLF(1–11) values were 1–16 (2–32) μM 4–128 (4 – >128) μM, respectively, against all the pathogens. The modified scaffolds containing the AMPs attached to the scaffolds, demonstrated the ability to kill 20–96% of P. aeruginosa, and between 60–70% of C. albicans. All the 3D bioprinted scaffolds showed no cytotoxicity towards CS‐MSCs.

Conclusions: We could successfully combine 3D bioprinting with immobilization of AMPs that show promising antimicrobial activity against two of the most dangerous pathogens to the cornea, while a good cytocompatibility for the CS‐MSCs could be achieved. Optimal bioink composition and cellularization of tissue equivalents are essential in fine‐tuning a method to promote the current 3D bioprinting technique as a future treatment modality for corneal regeneration.
Structurally enhanced perimetric examination
Authors: Evans Josephine , Crabb David , Ometto Giovanni , Montesano Giovanni
Published: January 2024

Aims/Purpose: To assess the use of structural data to guide perimetric examination.

Methods: Two perimetric strategies were tested on ten healthy participants: standard ZEST with population‐based prior distributions and Structural‐ZEST (S‐ZEST), enhanced with OCT data to determine the starting parameters. Both strategies were tested twice, in random order. The Compass Automated Perimeter (CMP, iCare) was used to collect the perimetric data through the Open Perimetry Interface and bespoke Shiny user interface (UI). The UI was used to import the Spectralis SD‐OCT scans (Heidelberg Engineering, Germany) and align the OCT data with the fundus image captured by the CMP. A 10–2 grid was centred on the fovea of each participant, aligned with the fovea‐disc axis. The UI calculated the Ganglion Cell Layer (GCL) thickness corresponding to each test location, after accounting for ganglion cell displacement. The starting priors for S‐ZEST were modelled using an independent dataset of glaucoma and healthy subjects. Bland–Altman plots were used to quantify test–retest variability. Bootstrap was used to calculate confidence intervals (CIs) and p‐values to compare the widths of the 95%‐Limits of Repeatability (LoR). Correlation between GCL thickness and sensitivity (dB) and the difference in test duration was calculated using linear mixed effect models. Agreement was quantified with the mean difference between the results of the two strategies.

Results: 95%‐LoRs for S‐ZEST of the two devices were similar (p = 0.829). The structure–function correlation was significant for both (p < 0.001), and very similar between S‐ZEST (R2 = 0.24) and ZEST (R2 = 0.23). There was a small but statistically significant mean difference in sensitivity between S‐ZEST and ZEST (0.56 [0.35, 0.77] dB, p = 0.034). S‐ZEST was 2.7 [1.2, 3.5] min faster than ZEST (p < 0.001).

Conclusions: S‐ZEST significantly shortened testing time without reducing repeatability in healthy observers.
Peripheral refraction and retinal activity with dual focus contact lenses for myopia control
Authors: Fernandes Paulo , Amorim‐de‐Sousa Ana , Queirós António , González‐Meijome José Manuel
Published: January 2024

Aims/Purpose: Contact lenses (CLs) for myopia control have shown optimistic eye growth retention in children but, the retinal mechanisms of defocus still unclear. This work evaluated the retinal response and peripheral refraction with a soft CL for myopia management in myopic eyes.

Methods: The visual acuity (VA), peripheral refraction and the retinal electrical activity were obtained from sixteen myopic (between −0.75 D and − 6.00 D, astigmatism >1.00 D) subjects (27.5 ± 5.7 years, 12 female), with two material‐matched CLs (Omafilcon A): a single‐vision CL (SV) and a myopia management dual‐focus CL (DF). Peripheral refraction was assessed with an open‐field autorefractometer (WAM‐5500, GrandSeiko Co. Lt) in four meridians separated by 45° at 2.50 meters distance. The global‐flash multifocal electroretinogram (gf‐mfERG) was recorded with the Reti‐port/scan21 (Roland Consult) using a stimulus of 61‐hexagons. The implicit time and response density (in nV/deg2) of the direct (DC) and induced (IC) components were analysed. Only the data of a single eye per subject was randomly used for analysis.

Results: The two CLs designs showed similar VA (p > 0.050). The DF induced a myopic shift of the SV peripheral refraction in most retinal eccentricities (p < 0.050). There were no differences in the implicit times of the retinal response between CLs designs. The DF increased the response density of both DC and IC components at all retinal areas, with a statistically significant difference in the parafoveal DC component (median difference of 2.77 [6.23–1.44] nV/deg2, p = 0.038).

Conclusions: The results showed that the retina responds differently to a SV and a DF CLs. The myopia management CL increased the electrophysiological response of the retina without affecting the time domain of the response. Besides other mechanisms potentially involved, the foveal and parafoveal retinal activities might be involved in the mechanism of myopia control with these lenses.
The aged mouse retina: Anatomical and functional study of retinal ganglion cells
Authors: Ramírez Kristy Tatiana Rodríguez , Muñoz María Norte , Ortega Alejandro Gallego , Vidal‐Sanz Manuel , Agudo‐Barriuso Marta
Published: January 2024

Aims/Purpose: the purpose of this work is to analyse anatomically and functionally the population of retinal ganglion cells (RGCs) throughout the mouse lifespan.

Methods: Retinal functionality was studied by electroretinogram in male and female C57BL/6J mice at 3, 6 and 18 months of age. Retinas were dissected as flat mounts at 3 and 18 months, the total number of RGCs immunodetected with Brn3a and automatically quantified.

Results: Regarding retinal functionality, we observed that the pSTR wave significantly decreased in males at 6 months (p < 0.01 vs. 3 months) and progressed significantly at 18 months (p < 0.01 vs. 6 months). In females, RGC functional decline was observed later than in males, at 18 months (p < 0.001 vs. 3 months). The loss of RGC functionality was not accompanied by RGC death, as the total number of RGCs remained constant in both sexes from 3 to 18 months of age.

Conclusions: Aging of the retina is associated with functional changes that may be due to neuronal dysfunction rather than cell loss.
Comparison of changes in ocular aberrations with accommodation and accommodative facility
Authors: García Maria Mechó , Carbonell María Arcas , Hospital Elvira Orduna , Cano Ana Sánchez
Published: January 2024

Aims/Purpose: This study aimed to analyse whether a relationship exists between subjectively measured monocular Accommodative Facility (AF), the magnitude of the revolution‐symmetric Zernike coefficients C20, C40 and C60, and the objectively measured Accommodative Response (AR).

Methods: A total of 66 eyes, from 33 healthy young volunteers (26 women and 10 men) with a mean age of 25.12 ± 3.40 years (range age 20–30) participated in this study. Three measurements were made for each eye with the aberrometer Hartmann‐Shack (IRX3, Imagine Eyes, Orsay, France). The stimulus vergence was increased from 0 to 5 D (near vision) in steps of 0.5 D. The AR for each Zernike coefficient was calculated as the difference between the value at 5 D and the value at 0 D, for 4.0 mm pupil size. Monocular assessment of AF was assessed monocularly and conducted at 40 cm ± 2.00 D flippers. Statistical analysis was performed to determine a relationship between the Zernike coefficients, AR and AF. The coefficient of determination (R‐squared) was calculated to measure the proportional amount of variance.

Results: The results showed that the highest values of R‐squared were obtained for the C20 coefficient measured at 5D of accommodation (R2 = 0.196, p < 0.01). Lower values were obtained for C40 and C60. The R‐squared values decreased from 0D (R2 = 0.097, p = 0.10) to 5D (R2 = 0.044, p = 0.60) for C40. However, there was an increase in R‐squared values from 0D (R2 = 0.0081, p = 0.47) to 5D (R2 = 0.058, p = 0.05) for C60.

Conclusions: No clear trends were found when comparing the Zernike coefficients C20, C40 and C60, analysed in three stages of accommodative demand compared with the accommodative facility measured.

The Zernikes coefficients analysed do not explain the differences in AF in this sample of young adult healthy eyes. However, there was found a trend that deserves further investigation.
Eyecare staff knowledge in three Belgium nursing homes
Authors: Moghaddam Zahra Javdani Sanatgar , Goes Frank
Published: January 2024

Aims/Purpose: Vision loss in elderly people may affect physical and mental health and speed up cognitive decline. Identifying visual dysfunction and staff education may improve ophthalmic care in nursing homes, but it is not yet known which practices have been implemented in Belgium.

Methods: Prospective cross‐sectional survey performed in Belgium between December 2022 and January 2023, by email and hardcopy. Survey questions were based on the literature, were focused on monitoring practices, staff knowledge, and other aspects shown to affect residents' vision care. Descriptive statistics and Chi‐Square analysis were used for data analysis.

Results: A total of 46 staff members (31 women, 15 men) of three Belgium nursing home staff were interviewed. The questionnaire revealed that there was not enough access to screening tools to identify vision impairments.

Conclusions: Access to monitoring procedures or screening tools are not commonly available staff education in Belgium nursing homes may be insufficient.

Keywords: Staff education, staff knowledge, nursing home, ophthalmic screening.
Relationships between regional retinal sensitivities assessed by microperimetry and their corresponding retinal layer thicknesses in healthy middle‐aged subjects
Authors: Puell María , Remis‐Gonzalez Melisa , Moreira‐Estebaranz Carolina , Cedrun‐Sanchez Juan
Published: January 2024

Aims/Purpose: To investigate relationships between regional differential light sensitivity (DLS) and inner and outer retinal layer (IRL and ORL) thicknesses in healthy middle‐aged adults.

Methods: Measurements were made in 42 eyes of 42 healthy individuals of mean age 51.3 ± 5.4 years (range 40–59 years), spherical equivalent (SE) between ±3.50 D and good visual acuity. Mesopic fundus‐controlled perimetry was used to measure regional DLS. Spectral‐domain optical coherence tomography (SD‐OCT) was used to measure IRL (ganglion cell‐related layer) and ORL thicknesses. DLS and retinal thickness measurements were recorded for five subfields: central fovea (1 mm diameter) and the quadrants temporal, nasal, superior, and inferior of a parafoveal ring of outer diameter 3 mm and inner diameter 1 mm. Relationships between regional DLS and corresponding IRL and ORL thicknesses were assessed through univariate and multivariate analysis.

Results: Mean DLS measured in the inferior parafoveal ring quadrant was significantly correlated with mean IRL thickness (rho = −0.50; p = 0.0045). This correlation was negative, meaning that a thicker IRL was related to a worse DLS. No significant correlations emerged between mean DLS and corresponding ORL or IRL thicknesses for the other subfields. Subsequent forward stepwise multiple linear regression analysis to correct for potential confounding factors revealed that IRL thickness and SE emerged as significant predictors of DLS in the inferior quadrant (R2 model = 33%; p = 0.0004).

Conclusions: A thicker macular IRL, possibly indicating transient gliosis, was associated with a worse DLS in healthy middle‐aged eyes.
A comparison of visual electrophysiology measures in optic neuropathy
Authors: Thompson Dorothy , Prise Katrina , Tucker Lisa , Roche Dermot , Handley Sian , Marmoy Oliver
Published: January 2024

Aims/Purpose: Our aim is to explore the inter‐relationship of clinical PVEP and PERG measurements with each other and the optic nerve structure in children investigated for possible optic neuropathies.

Methods: ISCEV Standard PVEPs and PERGs to 50′ check widths to large 30 and standard 15 degree fields were reviewed from children suspected to have optic neuropathy of various pathology. Amplitudes and peak times of PERG P50, N95, the N95:P50 amplitude ratio, the amplitude of the N95 from baseline and at 30 ms from the P50‐N95 slope were measured. Spectralis OCT RNFL sector measures and macular ganglion cell volumes were collated.

Results: PERG, PVEP with OCT measurements were available for 42 patients, (83 eyes) aged 6‐17 yrs. Those with abnormal PVEPs (33 eyes) had the most severe macular RGC volume loss (mean 0.26 mm3 in 3.45 mm) with mean LogMAR VA 0.52 (range − 0.01 to 1.00). These patients had inherited optic neuropathies, optic neuritis associated with MOGAD and RMMS. In contrast, patients with papilledema, such as associated with IIH, or presenting with headache and reduced vision and full discs had normal PVEPs. Mean VA LogMAR 0.23 (range − 1.0 to 0.9), and mean macular RGC volume 0.45 mm3 in 3.45 mm circle. N95:P50 amplitude ratios ranged from 1.83 to 0.44 in 30 degree fields and 2.16 to 0.36 in 15 degree fields. The N95:P50 amplitude ratios, slope at 30 ms and N95 from baseline correlated with macular RGC volume, but the best PERG discriminator (AUC 0.83) in the large field was the N95 slope measured at 30 ms. RNFL values were confounded by disc oedema in many cases.

Conclusions: Pattern reversal VEPs were abnormal in all patients with severe RGC volume loss. The PERG measures correlate with macular RGC volume. RNFL was confounded by disc oedema, but was helpful in highlighting temporal sector thinning in optic neuritis and inherited optic atrophy such as LHOA.

References

1. Odom JV, Bach M, Brigell M. et al. ISCEV standard for clinical visual evoked potentials: (2016 update). Doc Ophthalmol 133, 1–9 (2016). https://doi.org/10.1007/s10633-016-9553-y

2. Bach M, Brigell MG, Hawlina M, Holder GE, Johnson MA, McCulloch DL, Meigen T, Viswanathan S. ISCEV standard for clinical pattern electroretinography (PERG): 2012 update. Doc Ophthalmol 2013 Feb;126(1):1–7. doi: 10.1007/s10633‐012‐9353‐y. Epub 2012 Oct 17. PMID: 23073702.
Visual acuity testing in preschool children: Freiburg acuity test (FrACT) vs LEA symbols test
Authors: Farassat Navid , Jehle Vanessa , Heinrich Sven , Lagrèze Wolf , Bach Michael
Published: January 2024

Aims/Purpose: Cross‐sectional study to compare testability and performance of the Freiburg Visual Acuity Test (FrACT) and LEA Symbols Test (LEA) and to determine test–retest variability of visual acuities (VAs) achieved with the FrACT in preschool children.

Methods: Monocular VA of both eyes was measured in 136 preschool children (268 eyes) aged 3.0 to 6.8 years – once with the LEA and twice with a 4‐orientation Landolt C version of the FrACT. The monocular FrACT runs were preceded by a binocular run for explanatory purposes. The test order alternated between subjects. Optotypes were presented either on a computer monitor (FrACT) or on cards (Lighthouse Single Symbol Book; LEA) at a distance of 3 m.

Results: The overall testability of children was 70.1% for FrACT (188 of 268 eyes) and 90.3% for LEA (242 of 268 eyes). Testability depended markedly on age, with children aged <4 years at 23.0% (FrACT), 73.0% (LEA); ≥ 4 years: 88.1% (FrACT), 96.9% (LEA). The mean VA difference between FrACT and LEA was 0.11 LogMAR, with LEA reporting better acuity. The difference depended on age, with children aged <4 years exhibiting greater VA differences (0.27 LogMAR) while differences were smaller in children aged ≥4 years (0.09 LogMAR); in an additional adult control group the VA values of LEA and FrACT were even closer with 0.02 LogMAR mean difference. The 95% limits of agreement of test–retest‐variability of VAs in the FrACT were ± 0.29 LogMAR with a bias of 0.017 LogMAR (better acuity for the first test run).

Conclusions: The FrACT, as an examiner‐independent tool using international reference Landolt C optotypes, can be reliably used to assess VA in preschool children aged 4 years and older. We confirm that the LEA Symbols Test reports better acuity than tests based on Landolt rings.