Eleftherios Chatzimichail

Retinal graft survival and post-treatment visual improvement do not, alone or together, demonstrate functional cell replacement. Apparent benefit may reflect material transfer, trophic rescue, residual host function or procedural and measurement effects. This critical narrative review uses a structured PubMed search covering January 2020 to August 2026, supplemented by seminal studies, to assess retinal pigment epithelium (RPE), photoreceptor, retinal sheet or organoid, and retinal ganglion cell (RGC) transplantation. We separate mechanistic attainment, downstream outcomes and claim-specific causal confidence. Authentic RPE replacement requires donor epithelial function across the host interface, without new synapses. Photoreceptor replacement requires donor phototransduction and transmission to host retinal circuitry; composite grafts additionally require identification of the active donor components. RGC replacement requires both retinal afferent integration and functional reconnection with appropriate central targets. Selected photoreceptor studies demonstrate persuasive local physiological coupling, but durability, donor necessity and generalisability remain incompletely established. Human evidence principally supports feasibility, safety and graft-associated anatomy, rather than convincingly donor-mediated visual restoration. We propose a non-linear evidence framework in which outcomes cannot substitute for secure donor provenance, cell-specific function or host–graft coupling. Spatial concordance, durability, controls, disease-model relevance and experimental unit should qualify every claim.

Intravitreal inhibition of vascular endothelial growth factor (VEGF) has transformed the management of neovascular age-related macular degeneration, diabetic macular oedema and macular oedema secondary to retinal vein occlusion, but frequent monitoring and retreatment remain major burdens. Ocular half-life is often used as shorthand for durability, although the clinical interval is produced by a wider molecular and biological system. This narrative review examines how dose, molecular format, hydrodynamic size, binding affinity, valency, ligand spectrum, target turnover, tissue distribution and delivery architecture determine the time for which an eye remains controlled. Human ocular pharmacokinetic and pharmacodynamic evidence is interpreted according to compartment, assay and model provenance, with particular attention to the distinction between drug elimination, free-ligand suppression, anatomical control and protocol-assigned treatment interval. Trial evidence for ranibizumab, aflibercept, conbercept, brolucizumab and faricimab shows that extended dosing can arise from greater starting exposure, altered binding architecture or pathway expansion without a proportionate change in intrinsic ocular half-life. Patient phenotype and retreatment rules further modify the observed interval. Refillable reservoirs, biodegradable depots and ocular gene therapy change the governing kinetics from bolus elimination to controlled release or sustained local production, thereby increasing the importance of reversibility and cumulative safety. We propose that durability be defined as a time-to-threshold phenotype integrating active target-site exposure, biological demand, anatomical recurrence, all treatment-related procedures and safety. Standardised estimands, longitudinal human ocular sampling, spatial exposure methods and externally validated mechanism-informed models are needed to make molecular durability comparable and clinically actionable.

Age-related macular degeneration (AΜD) remains a leading cause of irreversible vision loss. Ιn neovascular AΜD (nAΜD), frequent intravitreal anti-VΕGF injections create substantial treatment burden, while approved therapies for geographic atrophy (GA) provide modest slowing of progression. Ocular gene therapy aims to achieve sustained intraocular expression of therapeutic proteins after a single administration. Τhis review summarises the biological rationale, vector platforms, and delivery routes relevant to AΜD, with emphasis on adeno-associated virus (AAV) systems, capsid engineering, and compartment-specific administration (intravitreal, subretinal, and suprachoroidal). We synthesise the clinical landscape for sustained anti-VΕGF expression approaches in nAΜD and complement-modulating strategies for GA, and highlight how trials increasingly prioritise injection-burden reduction, anatomical endpoints, and biomarkers of target engagement. Κey challenges include intraocular inflammation and neutralising antibodies (particularly with intravitreal dosing), variability and durability of transgene expression, surgical risks associated with subretinal delivery, and practical constraints related to manufacturing scale, cost, and long-term safety surveillance for non-removable therapies. Overall, gene therapy offers a plausible route towards durable, mechanism-targeted AΜD management, but its clinical role will depend on robust controlled trials and multi-year follow-up.

Introduction: Οcular manifestations of hidradenitis suppurativa (HS) are uncommon and typically include episcleritis, keratitis, and uveitis. We report a rare case of posterior scleritis and peripheral ulcerative keratitis (PUK) in a patient with HS. Case Presentation: A 44-year-old male with no significant systemic or ocular history presented with a painful corneal ulcer in the left eye, which was diagnosed as PUK. External examination showed facial scarring and only in the course and only during subsequent visits did he reveal his axillary lesions. Initial eye treatment with topical antibiotics and steroids led to marked improvement. Two weeks later, the patient developed pain in the right eye and was diagnosed based on clinical findings of posterior scleritis, which was confirmed by B-scan ultrasonography. Concurrent worsening of HS and the presence of a conjunctival granuloma. A conjunctival biopsy was performed alongside a comprehensive systemic work-up, both of which excluded infectious etiologies and systemic rheumatological autoimmune disease. The patient responded well to systemic corticosteroids and continues to demonstrate stable vision and ocular health during follow-up. Over thchatzimie course of his disease, he was diagnosed with peripheral ulcerative keratitis (PUK) and anterior scleritis in both eyes, with the addition of posterior scleritis in the left eye. Treatment at this stage included topical dexamethasone, tobramycin, and systemic corticosteroids. Marked improvement in ocular symptoms and visual acuity was achieved. Histopathological analysis of the conjunctival biopsy revealed a benign histiocytic granuloma without evidence of malignancy or Splendore-Hoeppli phenomenon. No systemic rheumatologic autoimmune disease, including sarcoidosis, was identified. Conclusion: This case highlights the importance of recognizing ocular involvement in HS, particularly posterior scleritis and PUK, which may indicate underlying autoinflammatory dysregulation. Interdisciplinary management is essential for preserving vision. To our knowledge, this is the first report of posterior scleritis, PUK and conjunctival granuloma in the context of HS.

Introduction: The aim of the study was to describe the favorable clinical outcomes of 2 patients with acanthamoeba keratitis (AK) following penetrating keratoplasty (PK), successfully managed with polyhexamethylene biguanide (PHMB) 0.08% monotherapy. Cases Presentation: Both patients developed recurrent AK after PK, confirmed by microbiological testing and polymerase chain reaction (PCR). Standard dual therapy with PHMB 0.02% and propamidine isethionate 0.1% was either ineffective or poorly tolerated due to ocular surface toxicity. Transition to PHMB 0.08% monotherapy resulted in marked clinical improvement, resolution of keratitis, and substantial visual recovery. At follow-up examination 9 months postoperatively for case 1 and 12 months postoperatively for case 2, both patients demonstrated clear corneal grafts with no signs of AK recurrence. Conclusion: PHMB 0.08% as monotherapy proved effective in managing recurrent AK after keratoplasty, achieving favorable anatomical and visual outcomes without recurrence during our follow-up period. These findings suggest that PHMB 0.08% monotherapy may serve as a viable alternative to conventional dual therapy, particularly in cases complicated by treatment intolerance or treatment failure. Further studies with larger cohorts and extended follow-up are warranted.

Corneal crosslinking (CXL) was first introduced in clinical practice in 2003. Since then, this procedure has been established as the first-line treatment in the management of progressive keratoconus. Over the last years, many different protocols have emerged, each one of them with variable clinical outcomes and safety profile. Progression of keratoconus after primary CXL is very rare, but it has been reported in the literature. This review summarises the existing data on repeated CXL after primary failure, emphasising on clinical efficacy and safety.

The refractive accuracy of intraocular lens (IOL) formulas varies in eyes that undergo combined phacovitrectomy for different underlying vitreoretinal pathology. A total of 401 eyes that underwent uncomplicated phacovitrectomy (23–25 g) with implantation of a plate haptic IOL (CT Asphina 409 M) in the capsular bag between April 2020 and December 2022 were included in the study. Inclusion criteria were postoperative best corrected visual acuity of 0.4 LogMAR or better at least 8 weeks after surgery. The Barrett Universal II (BUII), Haigis, Hill-Radial Basis Function (Hill-RBFv3.0), Hoffer Q, Holladay I, Holladay II, Kane, K6, Pearl-DGS and SRK/T formulas were compared for their accuracy in mean absolute error (MAE). Furthermore, all formulas were additionally tested by using the prediction for an IOL power 0,5 or 1D above the IOL used (IOLdown). Wilcox-Holladay-Wang-Koch (WHWK) statistical tests with Holm correction were applied. The Barrett IOLdown formula showed the lowest refractive prediction error (0.03D; together with Hill IOLdown), lowest MAE (0.40D), lowest median absolute error (MedAE; 0.31D), lowest standard deviation of MAE (0.55D) and lowest root mean squared absolute error (RMSAE; 0,54D). Barrett IOLdown had the highest percentage of eyes with predicted error within ± 0.25D (41.6%), Kane IOLdown within ± 0.50D (70.5%) and ± 0.75D (89%) and Hill IOLdown within ± 1D (95.2%). Except for Haigis, Hoffer Q and Pearl-DGS, all other formulas showed a statistically significantly lower MAE after IOLdown modification. The newest formulas with IOLdown modification performed better than old generation formulas, with Barrett IOLdown exhibiting the best results.

Glaucoma is a group of eye conditions characterised by optic nerve damage and visual field loss, representing the leading cause of irreversible blindness worldwide. Glaucoma exerts substantial global impact on visual impairment and blindness. The management of glaucoma has traditionally relied on medications such as prostaglandin analogs, beta-blockers, alpha agonists, and carbonic anhydrase inhibitors, which aim to lower intraocular pressure through various mechanisms. Rho kinase (ROCK) inhibitors have recently emerged as a novel class of antiglaucoma drugs, offering an alternative approach by enhancing aqueous humour outflow through the conventional pathway. Recent clinical studies assessing the efficacy and safety of Ripasudil (K-115) and Netarsudil (AR-13324) have demonstrated promising outcomes in the treatment of various types of glaucoma. Comparative studies have shown that ROCK inhibitors are non-inferior to traditional antiglaucomatous medications, such as beta-blockers and prostaglandins. Additionally, emerging evidence suggests their neuroprotective properties, which may play a role in preserving retinal ganglion cells. Furthermore, positive outcomes have been observed when these agents are used in conjunction with glaucoma filtering surgery, potentially enhancing surgical success rates. Adverse effects, including conjunctival hyperemia, cornea verticillata, conjunctivitis, and blepharitis, have been reported following the use of ROCK inhibitors. However, those side effects appear to be subtle in most cases. This review aims to provide an overview of ROCK inhibitors, focusing on their mechanisms of action, clinical efficacy, safety profiles, and additional benefits for eye health. Furthermore, further potential applications of ROCK inhibitors in glaucoma management are going to be discussed.

Unilateral ptosis accompanied by tumorous swelling of the upper eyelid can be caused by several conditions, ranging from benign to malignant etiologies. Possible causes include benign lesions such as chalazion or dermoid cyst, inflammatory conditions, foreign bodies, or malignant tumors like lymphoma or sebaceous gland carcinoma. Accurate differential diagnosis of these conditions requires a detailed ocular history and thorough diagnostic evaluation, including clinical examination, imaging, and, sometimes, biopsy. Initial attempts of scleral buckle surgery date back to the mid-20th century, when Custodis introduced a polyviol explant [1]. Nowadays, explants are typically made from silicone material, either in solid form or as a sponge. Possible complications of scleral buckling include scleral perforation and rupture, choroidal detachment, persistent subretinal fluid, macular edema, epimacular proliferation, refractive changes, diplopia, infection, scleral abscess, and late periorbital infections, sometimes associated with implant extrusion [2]. A rare complication is also buckle migration [3]. In our case, clinical manifestation initially resembled an upper eyelid tumor with ptosis, requiring consideration of various benign and malignant etiologies. However, a thorough medical history and appropriate diagnostic tests ultimately guided us to the diagnosis of buckle dislocation. Received: 25 October 2024 Accepted: 17 December 2024 Article published online: 27 February 2025 © 2025. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

Hydrogen peroxide is a disinfectant commonly used in lens care solutions, eliminating microorganisms by producing free radicals that disrupt cell membranes and vital cellular components. It has been utilized for contact lens cleaning since the 1970 s [1]. Corneal toxicity can result from chemical injury as well as topic or systemic medications [2], [3]. The clinical signs of corneal toxicity vary widely and may include superficial punctate keratitis pseudodendritic keratitis, filamentary keratitis, persistent epithelial defects, or even severe ulcerative keratitis [2]. Received: 27 October 2024 Accepted: 06 January 2025 Article published online: 27 February 2025 © 2025. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany