Search Results (516)

Background: Optical coherence tomography (OCT) and OCT angiography (OCTA) retinal imaging in inherited retinal dystrophies (IRD) has been limited to the posterior pole and central midperiphery (up to about 16.5 × 16.5 mm). Two novel commercially available swept-source (SS) OCT/-OCTA devices provide the possibility of wide-field (WF) evaluation of retinal and choroidal structures, including the vasculature, in a single examination. Methods: A limited consecutive series of 16 IRD patients were examined with a BMizar (400 kHz, 24 × 20 mm scan width) and a Dream OCT (200 kHz, 26 × 21 mm scan width) in addition to the normal clinical examination protocol. This series included patients with retinitis pigmentosa, cone-rod dystrophy, macular dystrophy and autosomal recessive bestrophinopathy. In addition, 12 healthy probands were examined. Results: WF-SS-OCT/-OCTA enabled the detection of retinal, choroidal and choriocapillaris alterations in the macular and midperiphery in a short, single examination session of up to 15 s. Even small foveal lesions and a small silent macular neovascularization were detected on WF screening. Regional alterations of choroidal and choriocapillaris flow patterns were identified. These were mostly in correspondence with areas that appeared clinically affected, but unexpected lesions were identified as well. Occlusion of peripheral retinal vessels was seen in retinitis pigmentosa, though flow was detected in retinal vessels, which were difficult to distinguish on fundus images. In one patient with nystagmus, WF-SS-OCT/-OCTA was performed, whereas standard OCT volume scan could not be obtained. The most frequent artifact were horizontal lines of misalignment, which did not interfere with the detection of pathologies. Conclusions: Both WF-SS-OCT/-OCTA devices provide detailed insights in structural and vascular retinal and choroidal alterations in a single, short examination. Larger series of IRD patients examined with WF-SS-OCT/-OCTA promise to provide novel insights into the pathology of IRDs. Full article

Purpose: We aimed to compare the volume of the lateral geniculate nucleus (LGN) in patients with different stages of retinitis pigmentosa (RP) with regard to age, sex and symmetry of the LGN. Methods: The investigated cohort included 13 patients with moderate (median Snellen visual acuity 0.75) and 18 patients with advanced (median Snellen visual acuity 0.06) RP-related visual field loss. The volumes of the left and right LGNs were manually measured using ITK-SNAP software after an examination of the brain with a 7 Tesla MRI. A linear mixed statistical model was used to assess LGN volume regarding age and gender of moderate and advanced RP patients and symmetry of both LGNs. Results: The mixed-effects linear model did not reveal a significant effect of disease group on LGN volume after adjusting for age and sex (F(1.27) = 0.01, p = 0.91). A significant effect of the LGN side was demonstrated, with the volume of the right LGN being significantly greater than that of the left (F(1.29) = 29.45, p < 0.001) in both disease groups, left–right. The interaction between disease group and LGN side was not statistically significant (F(1.29) = 0.45, p = 0.51). There is a tendency for LGN to decrease with age (F(1.27) = 3.84, p = 0.060), and there is no gender predilection (F(1.27) = 0.11, p = 0.74) in RP patients. There was correlation found between left LGN volume and visual acuity (ρ = 0.64) and central retinal thickness (ρ = 0.71) in the moderate group). Conclusions: No significant differences in LGN volume were found between patients with moderate and advanced RP. Furthermore, the volume of the right LGN was larger than the volume of the left LGN in RP patients, and this asymmetry is not gender-dependent. Correlation was found between the left LGN volume and visual acuity and central retinal thickness in moderate group. Our findings may have clinical implications for future RP management. Full article

Photobiomodulation (PBM) is a non-invasive therapeutic strategy that uses red and near-infrared (NIR) light in the 590–950 nm range to modulate the cellular and molecular pathways involved in retinal homeostasis. At the molecular level, PBM acts primarily through photon absorption by cytochrome c oxidase (CcO, complex IV of the mitochondrial electron transport chain), whose four metal centres—two copper (CuA and CuB) and two heme groups (heme a and heme a₃)—absorb light across approximately 600–1000 nm. Photon capture promotes photodissociation of inhibitory nitric oxide (NO) from the binuclear CuB–heme a₃ centre, accelerates electron transfer, restores the proton-motive force and increases ATP synthesis. These primary events trigger a coordinated molecular programme that includes (i) transient mitochondrial reactive oxygen species (ROS) bursts that activate the Nrf2/Keap1/ARE axis and upregulate phase II antioxidant enzymes (HO-1, NQO1, GCLC, SOD2, catalase, GPx); (ii) calcium- and cAMP-dependent secondary signalling that converges on PI3K/Akt, MAPK/ERK, AMPK and mTOR pathways; (iii) suppression of NF-κB-driven cytokine production (TNF-α, IL-1β, IL-6) and of NLRP3 inflammasome activation; (iv) downregulation of the HIF-1α/VEGF axis, particularly at 590 nm; (v) anti-apoptotic remodelling of the Bcl-2/Bax ratio with reduced cytochrome c release and caspase-3/9 activation; and (vi) PGC-1α/TFAM/NRF1-driven mitochondrial biogenesis, alongside restoration of fission/fusion homeostasis (Drp1, Mfn1/2, Opa1) and PINK1/Parkin-mediated mitophagy. Wavelength specificity has a defined molecular basis: 590 nm modulates VEGF signalling and RPE pump activity, 660 nm interacts with the CuB centre and enhances O₂ binding at CcO, and 850 nm is absorbed by CuA and supports electron entry into complex IV. A second molecular axis is the bidirectional crosstalk between PBM and the circadian system: mitochondrial respiration, ATP turnover and CcO activity oscillate over the 24 h cycle under the control of the BMAL1/CLOCK and PER/CRY core machinery, the NAD⁺/SIRT1–SIRT3 axis and REV-ERBα. Preliminary preclinical and human observations suggest that NIR-induced bioenergetic and functional gains may be coupled to this rhythm, with greater benefit reported when light is delivered in the morning window (≈08:00–11:00); this time dependence should be regarded as an emerging hypothesis rather than an established clinical principle. The clinical evidence is unevenly developed across indications. It is most robust for non-exudative age-related macular degeneration, where multiwavelength PBM (590/660/850 nm; Valeda Light Delivery System) has shown disease-modifying potential in randomized controlled trials (LIGHTSITE I–III and the LIGHTSITE IIIB extension), with sustained BCVA gains and reduced incidence of geographic atrophy over 24 months and beyond. Evidence for retinitis pigmentosa, central serous chorioretinopathy and, with red-light monotherapy, childhood myopia is at present limited to small or short-term studies and remains preliminary. This narrative review synthesizes the molecular machinery engaged by PBM, integrates clinical findings across retinal diseases and discusses how chronotherapeutic delivery of light, aligned with the molecular clock, may further optimize therapeutic efficacy. Full article

Background and Clinical Significance: Biallelic pathogenic variants in the PCARE gene (photoreceptor cilium actin regulator), also known as C2orf71 (chromosome 2 open reading frame 71), are typically associated with retinitis pigmentosa type 54 (RP54) and, less frequently, with cone–rod dystrophy (CORD23). Case Presentation: A 52-year-old man presented with an eight-year history of progressive visual loss, without photophobia or nyctalopia. He underwent a comprehensive ophthalmological evaluation, including multimodal retinal imaging, automated perimetry, and full electrophysiological testing, in accordance with International Society for Clinical Electrophysiology of Vision (ISCEV)’s standards. Genetic testing was performed using next-generation sequencing (NGS) with an inherited retinal dystrophy gene panel, and findings were confirmed by Sanger sequencing. Clinical examination revealed bilateral macular atrophy with minimal foveal sparing and a central scotoma. Optical coherence tomography (OCT) showed disruption of the outer retinal layers and retinal pigment epithelium (RPE) abnormalities. Fundus autofluorescence (FAF) demonstrated central hypoautofluorescence surrounded by a hyperautofluorescent ring. Electrophysiological testing revealed severely reduced rod- and cone- mediated responses on full-field electroretinography (ERG), absent pattern ERG responses, and markedly reduced multifocal ERG responses, indicating widespread retinal dysfunction with significant macular involvement. Genetic analysis identified a homozygous pathogenic nonsense variant in PCARE [c.3289C>T; p.(Gln1097*)], confirming the diagnosis of an autosomal recessive inherited retinal dystrophy. Conclusions: Biallelic PCARE variants can cause late-onset severe retinal dystrophy, with predominant macular involvement and cone–rod dysfunction. Given its phenotypic overlap with other inherited retinal diseases, accurate diagnosis requires the integration of multimodal retinal imaging, electrophysiological testing, and comprehensive genetic analysis. Full article

Objectives: This study investigated a variant, RPGR NM_001034853.2 c.1307G>A, p.[Gly436Asp, p?], in a large Irish pedigree with severe X-Linked Retinitis Pigmentosa (XLRP). The effect of the variant on RNA splicing was interrogated using in vitro functional analysis to provide evidence of disease causality. Methods: Three related individuals presenting with XLRP underwent target-capture sequencing, together with confirmatory Sanger sequencing and cascade analyses, to identify candidate variants. In silico investigations were undertaken using SpliceAI (version 1.3.1) and Alamut Visual software (version 2.13), among others. Functional analyses using in vitro midigene splice assays employing gateway expression vectors were undertaken. Variant and wildtype RNA were amplified by RT-PCR to investigate effects on splicing. RPGR c.1307G>A was subsequently reclassified using ACMG/AMP and ClinGen SVI recommendations. Results: Midigene investigation confirmed a cryptic acceptor site is being utilised together with the cryptic branchpoint motif to excise intron 10 and 90 bases of exon 11, leading to a frameshift and the creation of a premature stop codon. No functional RPGR transcript is predicted to remain. Given evidence of aberrant splicing, the variant classification was upgraded to pathogenic. Conclusions: RPGR c.1307G>A leads to creation of a cryptic branchpoint within an exon, resulting in protein truncation with deleterious effect(s). To the best of our knowledge, this is the first variant that leads to creation of a cryptic branchpoint within an exon associated with any IRD. The results illustrate the importance of investigating the functional consequences of both coding and non-coding variants with a predicted impact on splicing to understand their pathogenicity. Full article

Optogenetic gene therapy-based treatment offers a unique approach to bypass dysfunctional or degenerated photoreceptors in retinal degenerative disorders. Ambient light-activatable multi-characteristic opsin (MCO) targeted to bipolar cells of the retina has demonstrated partial vision restoration in animal models of retinitis pigmentosa (RP). Here, we describe the potential therapeutic efficacy of intravitreally delivered AAV-carried MCO-010 in a mouse model of Stargardt disease. MCO-010 treatment led to significantly improved behavioral outcomes in the visually guided radial arm water maze. Furthermore, longitudinal optical coherence tomographic imaging showed that the MCO-010 treatment led to no notable change in the retina thickness. Furthermore, the MCO-010-treated mice exhibited higher electrophysiological responses compared to the control group. Together, these findings demonstrate potential vision-restoring and disease-modifying aspects of ambient light-activatable intravitreal MCO-010 therapy. Full article

Background/Objectives: Retinitis pigmentosa (RP) is characterized by progressive degeneration of photoreceptors, with increasing evidence supporting the involvement of inflammation in disease progression. Aqueous humor (AH) reflects the intraocular microenvironment and represents an accessible source for biochemical analysis. This study aimed to characterize the profile of the main inflammatory proteins and bioactive lipids in the AH of RP patients and to compare it with healthy subjects. Methods: The AH was analyzed for cytokines using multiplex immunoassays and for lipid species using liquid chromatography–mass spectrometry. The concentrations of the analyzed molecules were compared between RP patients and the control group and then correlated with age and ellipsoid zone (EZ) width in RP patients. Results: A total of 26 RP patients and 13 controls were recruited. Significantly elevated levels of the pro-inflammatory IL-6 and a significant decrease in vascular endothelial growth factor (VEGF) were found in RP patients compared to controls. In RP patients, lipidomic analysis demonstrated significant increases in medium- and long-chain sphingomyelins (SMs) and very-long-chain unsaturated phosphatidylcholines (PCs). Higher levels of Cer 16:0, PC 32:0, and PC 34:0 were significantly associated with greater EZ preservation in RP patients. Additionally, in RP patients, VEGF and GM-CSF levels increased significantly with age, while IL-8 showed a non-significant decreasing trend. Conclusions: By integrating proteomic and, for the first time, lipidomic analyses of AH, we identified significant alterations in pro-inflammatory cytokines and bioactive lipid species in RP patients compared to controls, further highlighting a link between inflammatory activity, patient age, and disease stage. These preliminary findings need further validation in larger longitudinal cohorts to confirm the clinical utility of these bioactive mediators as potential disease biomarkers. Full article

Retinitis pigmentosa (RP) is a genetically heterogeneous group of inherited retinal degenerations with primary degeneration of rod photoreceptors followed by secondary cone loss. We investigated whether downregulating Nrl (neural retina leucine zipper), a key transcription factor specifying rod fate, can reprogram rods into a more resilient state. In a transgenic Nrl^N/N mouse in which Nrl was markedly downregulated, the rod phenotype became more like a rod precursor, particularly in the inferior retina. Crossing Nrl^N/N mice with two rod degeneration models, rd1 (Pde6b^rd1/rd1) and rhodopsin P23H knock-in (Rho^P23H/P23H) mice, showed significantly improved photoreceptor survival in double-mutant mice. In addition, AAV-mediated delivery of shRNA targeting Nrl mRNA substantially enhanced photoreceptor survival in rd10 (Pde6b^rd10/rd10) mice. These findings demonstrate that downregulation of Nrl reprograms rods and confers broad resistance to degeneration across multiple RP models. AAV-mediated Nrl knockdown represents a promising mutation-independent therapeutic strategy for autosomal recessive and dominant forms of RP. Full article

Background: Retinal and optic nerve disorders remain major causes of visual morbidity worldwide. Ocular fundus flavoprotein fluorescence (FPF) imaging has emerged as a potential noninvasive biomarker of mitochondrial dysfunction for earlier detection and evaluation of disease severity. Methods: We conducted a Systematic Scoping Review of the diagnostic and correlational utility of quantitative FPF parameters in retinal and optic nerve diseases compared with healthy controls. Following PRISMA-ScR guidelines, we searched MEDLINE, Web of Science, Scopus, and CENTRAL for peer-reviewed human studies available online before 31 December 2025. Results: Seventeen studies were included, encompassing 1914 eyes and 1339 participants, and were predominantly cross-sectional. In healthy eyes, mean macular and optic nerve head FPF intensity were reported as 24.1 ± 12.2 gsu and 30.6 ± 14.6 gsu, respectively. Higher signals were reported in several disorders, including diabetes mellitus (76.0 [67.0–92.0] gsu), neovascular age-related macular degeneration (67.47 ± 17.77 gsu), and retinitis pigmentosa (50.5 ± 12.2 gsu). However, lower, unchanged, or stage-dependent signals were also observed within the same disease categories. Interpretation across studies was limited by substantial heterogeneity in patient selection, disease definitions, imaging protocols, control groups, and FPF outcome metrics. The precise cellular and sublayer origin of the detected signal also remains challenging to determine. Conclusions: Ocular fundus FPF imaging provides promising metabolic insight into retinal and optic nerve diseases. However, current evidence remains heterogeneous and largely cross-sectional, limiting clinical interpretability and generalizability. Longitudinal studies, technical standardization, and multimodal integration are needed to define reproducible disease-specific FPF profiles and improve translational applicability. Full article

Inherited retinal dystrophies (IRDs) comprise a diverse group of genetic disorders that frequently result in irreversible vision loss due to photoreceptor dysfunction or degeneration. Among them, retinitis pigmentosa (RP) and achromatopsia (ACHM) are, in some cases, associated with pathogenic variants in PDE6A and PDE6C, respectively, which are key components of the phototransduction cascade. As most of IRDs still lack effective therapies, retinal organoids (ROs) provide a valuable in vitro model for the investigation of disease-associated mechanisms. Here, we generated induced pluripotent stem cell (iPSC)-derived ROs from an RP patient carrying compound heterozygous PDE6A mutations and from a patient with ACHM harboring a homozygous PDE6C mutation, along with their corresponding CRISPR/Cas9-corrected isogenic controls, which, to our knowledge, represent the first patient-derived RO models reported for the PDE6A and PDE6C genes. The mutant PDE6A line exhibited impaired neuroretinal vesicle formation and RO differentiation; however, a subset of RP-derived ROs matured appropriately and retained photoreceptor features. Moreover, the specific isoform expression pattern detected in retinal tissues reflected differences across developmental maturation stages that could influence disease severity. In contrast, the PDE6C_mutant ROs displayed normal structure and maturation, although cGMP hydrolysis within photoreceptors was likely compromised. In both models, CRISPR/Cas9-mediated correction restored the disease-associated phenotype resembling wild-type ROs. Collectively, these findings provide new insights into PDE6-associated pathogenesis, underscore the utility of patient-specific and gene-corrected ROs for elucidating IRD mechanisms, and support gene editing as a promising therapeutic strategy. Full article

Purpose: To evaluate the safety and feasibility of repeated subtenon administration of autologous platelet-rich plasma (PRP) in patients with degenerative retinal diseases and to explore preliminary, hypothesis-generating functional observations in retinitis pigmentosa (RP) and extensive macular atrophy with pseudodrusen-like appearance (EMAP). Methods: This prospective, open-label, uncontrolled pilot study included 13 patients (6 RP, 7 EMAP) who received three subtenon PRP injections (1.5 mL each) at baseline, Month 2, and Month 4, with follow-up through Month 6. The study was designed primarily to assess safety and feasibility and was not powered or intended to evaluate efficacy. The primary outcome was safety, including adverse events and intraocular pressure changes. Exploratory secondary outcomes included best-corrected visual acuity (BCVA, logMAR), visual field mean deviation (MD), and structural optical coherence tomography (OCT) parameters. Electrophysiological outcomes were analyzed descriptively due to incomplete paired data. Analyses were conducted within diagnostic groups, and no between-group comparisons were performed. Results: All 13 patients completed the study. No serious adverse events or permanent ocular morbidity were observed. Two transient and self-limited adverse events occurred (anterior uveitis and intraocular pressure elevation), both resolving without sequelae. In the overall cohort, BCVA remained stable without statistically significant change. In the RP subgroup, a small exploratory change in BCVA was observed (mean ΔlogMAR −0.09; nominal p = 0.048), corresponding to approximately 4–5 ETDRS letters; however, this finding was associated with wide confidence intervals and limited statistical power and should be interpreted cautiously. In the EMAP subgroup, functional stability was observed without evidence of consistent improvement. Visual field mean deviation and OCT findings were consistent with absence of short-term deterioration across available paired data. Electrophysiological outcomes showed no consistent directional change. Conclusions: Repeated subtenon PRP administration appeared feasible and well tolerated in this small, uncontrolled pilot cohort. Any observed functional changes are preliminary and hypothesis-generating only and do not establish efficacy. Larger, adequately powered controlled studies with standardized endpoints are required to determine the potential role of PRP in degenerative retinal diseases. Full article

Background: Non-syndromic retinitis pigmentosa (RP) is characterized by rod–cone degeneration, resulting in night blindness, visual field constriction, and eventual blindness. Recessively inherited RP is predominantly exacerbated in consanguineous populations, such as Pakistan. This study aimed to perform the genetic analysis of sixteen non-syndromic RP segregating Pakistani families, and to summarize the mutation spectrum of non-syndromic RP in our population by reviewing related literature. Methods: We screened 16 non-syndromic RP families using targeted capture panel sequencing of 344 genes related to inherited retinal dystrophies. Variants were prioritized based on rarity (minor allele frequency (MAF) < 0.001 in the gnomAD South Asian subset), pathogenicity assessments using ACMG/AMP criteria, and REVEL scores (>0.5). Candidate variants were validated for familial segregation through Sanger sequencing. Results: We identified 15 distinct variants across 14 genes associated with non-syndromic retinitis pigmentosa, comprising 6 missense, 7 nonsense, 1 frameshift, and 2 splice-site variants, including 4 novel variants, i.e., p.(Val220Met) and p.(Pro1282SerfsTer2) in RP1, 1 each in PDE6B (c.2021+5G>A), and PRCD p.(Ser38Ter). Homozygosity predominated, underscoring the impact of consanguinity on the burden of autosomal recessive disease in the present cohort, while the CERKL disease-causing mutation, i.e., p.(Arg257Ter), recurred in two families. Conclusions: This study expands Pakistan’s non-syndromic RP mutational spectrum by identifying novel variants in RP1, PDE6B, and PRCD, alongside recurrent CERKL and RHO mutations of the local population. The literature review suggests that RP1, TULP1, and PDE6B are among the most mutated genes in our population, supporting the value of population-specific genetic panels to enhance diagnostics and carrier screening. Full article

Coenzyme Q10 (CoQ10), a natural antioxidant produced by the human body, has strong anti-inflammatory properties, reduces oxidative stress, and improves mitochondrial function. It is also known for its strong neuroprotective effects. With age, endogenously produced CoQ10 levels decline, contributing to the development of chronic diseases, including eye disorders. Irreversible ocular diseases that result in blindness present a significant challenge in contemporary medicine, as no fully effective cure exists; current treatments primarily aim to decelerate disease progression, manage symptoms, and preserve residual vision. Our study reviews research on the use of CoQ10 in eye diseases like age-related macular degeneration (AMD), retinitis pigmentosa (RP), and glaucoma, which can cause permanent vision loss and are linked to oxidative stress and mitochondrial dysfunction. This article explores whether CoQ10 can be a safe and effective addition to treatment for these conditions. We also outline directions for future research and explain how CoQ10 functions in the studies discussed in this review. Full article

Background/Objectives: To describe retinal imaging characteristics and the natural history of rhodopsin (RHO)-associated autosomal dominant retinitis pigmentosa (ADRP) by evaluating ellipsoid zone (EZ) width loss and measuring the degree of constriction of the area within and including the hyperautofluorescent ring. Methods: Eighteen patients with molecularly confirmed RHO variants were retrospectively evaluated. EZ width on spectral-domain optical coherence tomography (SD-OCT) and the area within and including the hyperfluorescent ring on fundus autofluorescence (FAF) were measured. The correlation between EZ width and hyperfluorescent ring area was assessed using a linear mixed-effects model. Results: Mean best corrected visual acuity (BCVA) (logMAR) was 0.21 at baseline and 0.29 at last visit over a mean follow-up of 5 years. Nine patients presented with sectoral RP, eight with typical RP, and one with unilateral RP. The mean EZ width constriction rate was −93.43 µm/year (SD = 130.58), and the area within and including the hyperautofluorescent ring decreased by −0.54 mm²/year (SD = 0.50). A strong positive association was observed between the EZ width and hyperfluorescent ring area at baseline (β = 151.7 ± 17.9, p < 0.001) and at the final visit (β = 185.7 ± 18.2, p < 0.001). Conclusions: In this study, patients with RHO-associated ADRP appeared to show a relatively slow rate of progression. Quantitative imaging markers, such as EZ width and the area within and including the hyperautofluorescent ring, may offer potentially reproducible measures of disease progression. These imaging biomarkers could be useful as outcome measures in future natural history studies and therapeutic trials, pending further validation. Full article

Objectives: To evaluate the long-term effects on retinal structure and visual function of oral bromelain and curcumin supplementation in patients with inherited retinal dystrophies (IRD) complicated by persistent cystoid macular oedema (CMO). Methods: We retrospectively studied 20 eyes with genetically confirmed IRD complicated by CMO, with refractory to systemic or local treatments performed for 6 months. We collected baseline (V1) and follow-up (V2) data from these IRD-CMO patients, who were continuously supplemented with oral bromelain and curcumin for 12 months. Outcome measures were the Snellen best-corrected visual acuity (BCVA) and central macular thickness (CMT) values, collected by spectral-domain optical coherence tomography (OCT). Based on OCT scans, we classified IRD-CMO as microcystic or macrocystic, performing this sub-grouping in two eye cohorts (n = 10). Baseline median BCVA and CMT differences in both groups were verified (Mann–Whitney test). For both CMO groups, changes from V1 to V2 in median BCVA and CMT values were evaluated (Friedman test). Results: At baseline, both the median BCVA and CMT values were significantly different in both groups (p < 0.01 and p < 0.001). Between V1 and V2, in the microcystic CMO group, a slightly improved median BCVA was found, whereas the median CMT was reduced; however, this did not reach statistical significance (p = 0.6 and p = 0.2, respectively). In the macrocystic CMO group, a significant stable median BCVA was found from V1 to V2, with concomitant significant reduction in median CMT (p < 0.05 for both comparisons). Conclusions: Retinal structural improvement and visual function preservation were observed after oral bromelain and curcumin supplementation in macrocystic IRD-CMO. It is likely that the vasogenic component in macrocystic CMO is more responsive to nutraceutical molecules than the degenerative microcystic component. Full article