Ioannis Tsinopoulos

Cell-based therapeutics are redefining interventions for vision loss by enabling tissue replacement, regeneration, and neuroprotection. This review surveys contemporary cellular strategies in ophthalmology through the lenses of therapeutic effectiveness, translational readiness, and governance. We profile principal sources—embryonic and induced pluripotent stem cells, mesenchymal stromal cells, retinal pigment epithelium, retinal progenitor and limbal stem cells—and enabling platforms including extracellular vesicles, encapsulated cell technology and biomaterial scaffolds. We synthesize clinical evidence across age-related macular degeneration, inherited retinal dystrophies, and corneal injury/limbal stem-cell deficiency, and highlight emerging applications for glaucoma and diabetic retinopathy. Delivery routes (subretinal, intravitreal, anterior segment) and graft formats (single cells, sheets/patches, organoids) are compared using standardized structural and functional endpoints. Persistent barriers include GMP-compliant derivation and release testing; differentiation fidelity, maturation, and potency; genomic stability and tumorigenicity risk; graft survival, synaptic integration, and immune rejection despite ocular immune privilege; the scarcity of validated biomarkers and harmonized outcome measures and ethical, regulatory, and health-economic constraints. Promising trajectories span off-the-shelf allogeneic products, patient-specific iPSC-derived grafts, organoid and 3D-bioprinted tissues, gene-plus-cell combinations, and cell-free extracellular-vesicle therapeutics. Overall, cell-based therapies remain investigational. With adequately powered trials, methodological harmonization, long-term surveillance, scalable xeno-free manufacturing, and equitable access frameworks, they may eventually become standards of care; at present, approvals are limited to specific products/indications and regions, and no cell therapy is the standard of care for retinal disease.

Background/Objectives: Tacrolimus, an immunosuppressant, is increasingly used topically in ophthalmology, particularly for conditions like vernal keratoconjunctivitis and post-keratoplasty rejection prophylaxis. This systematic review aims to evaluate the efficacy and safety of topical tacrolimus in these ocular conditions. Methods: A thorough search was conducted in PubMed and Cochrane Library for relevant studies published up to 16 March 2025. Studies were eligible for inclusion if they were randomized controlled trials investigating topical tacrolimus in human ocular disease, were published in English, and reported clearly defined outcomes. Exclusion criteria included non-randomized studies, animal studies, systemic treatments, non-English publications, and studies lacking clearly reported outcomes. Data regarding study design, patient demographics, intervention details, and outcomes were extracted and analyzed. The Cochrane risk-of-bias tool (RoB 2.0) was used to assess the risk of bias. Results: A total of 10 studies met the inclusion criteria, were retrieved, and were categorized as not highly biased after the risk-of-bias assessment. These studies were included in the systematic review, where a qualitative analysis took place. Our analysis revealed that the topical use of tacrolimus showed promising results, as it improved clinical signs and symptoms in most patients. In half of the studies, tacrolimus demonstrated superior efficacy compared to the control group, while in the remaining studies, it showed equivalent efficacy. Adverse effects, such as a burning sensation, were noted in 7/10 studies but were generally mild. The methodologies were somewhat heterogeneous, and some studies had small sample sizes. Conclusions: Topical tacrolimus shows promising effects in managing various ocular surface diseases. While randomized controlled trials provide evidence, further research with larger sample sizes is necessary to solidify its efficacy and safety profile compared to other immunosuppressants.

Background/Objectives: Intraocular pressure (IOP) readings using three different methods (Goldmann applanation tonometry (GAT), Corvis ST, and iCare) were compared in patients who underwent penetrating keratoplasty (PK). Methods: An observational cross-sectional study with prospective recruitment of patients was conducted. IOP measurements were acquired using GAT, iCare, and Corvis (including both uncorrected IOP (CVS-IOP) and biomechanical IOP (bIOP)), and the agreement among methods was analyzed using Bland–Altman plots. Secondary outcomes included the influence of CCT, the number of sutures, the size of the corneal donor button, and the use of antiglaucoma topical medications on the IOP readings using the three methods. Results: Twenty-five eyes from 25 patients were included. The Bland–Altman analysis showed the narrowest limits of agreement (LoA) between GAT and bIOP (7.5 mmHg). The difference between iCare and GAT IOP showed a bias of 1.26 ± 3.8 mmHg, with increased variability in cases with more remaining sutures (p = 0.0079). A higher CCT was moderately associated with lower bIOP readings (p = 0.0067), but no significant impact of CCT on the difference in the IOP measurements between GAT and other tonometers was found. Additionally, there were no significant differences in tonometer readings based on the use of antiglaucoma medications or the corneal donor button size. Conclusions: Good agreement was found between iCare, CVS-IOP, bIOP, and GAT-IOP readings with the comparison between GAT-IOP and bIOP resulting in the narrowest 95% LoA. The difference between the GAT-IOP and iCare readings tended to be influenced by the number of sutures at the graft–host interface. Higher CCT values were associated with lower bIOP readings; however, the differences in tonometer readings compared to GAT-IOP were not found to be influenced by CCT.

Objective: This paper compares two popular techniques for tear trough correction—fat repositioning and hyaluronic acid (HA) fillers—highlighting their efficacy, safety profiles, patient satisfaction, and associated complications. Methods: A narrative review of 20 studies comparing fat repositioning and HA fillers was conducted, focusing on parameters such as duration of results, volume restoration, complication rates, and patient satisfaction. Results: Fat repositioning provides long-lasting results but carries higher surgical risks compared with HA fillers. The transconjunctival approach is suitable for patients with minimal skin excess. The supraperiosteal plane allows for a quicker procedure and, despite postoperative edema and temporary irregular contouring, shows no difference in final cosmetic outcomes compared with other planes. Internal fixation reduces the risk of fat relapse and skin scarring but carries the risk of suboptimal positioning. HA fillers offer immediate, minimally invasive results but require periodic maintenance. The use of a cannula reduces the risk of vascular occlusion. Combining a high G’ filler for the midface with a low G’ with low hydrophilicity for the tear trough reduces the amount of filler needed and prolongs the results. Both surgical and non-surgical methods are effective, depending on patient needs and anatomical considerations. Conclusions: Fat repositioning is ideal for patients seeking long-term correction and are willing to undergo surgery, while HA fillers suit those preferring non-invasive treatments with customizable, short-term effects. Both techniques have pros and cons that must be matched to patient goals and conditions.

Trachoma is the most common infectious cause of blindness worldwide. This review investigates the pathogenesis of trachoma, focusing on its causative agent, transmission pathways, disease progression, and immune responses. Trachoma is caused by serovars A–C of the bacterium Chlamydia trachomatis (Ct). Transmission occurs through direct or indirect exchanges of ocular and nasal secretions, especially in regions with poor hygiene and overcrowded living conditions. The disease is initiated in early childhood by repeated infection of the ocular surface by Ct. This triggers recurrent chronic inflammatory episodes, leading to the development of conjunctival scarring and potentially to trichiasis, corneal opacity, and visual impairment. Exploring the pathogenesis of trachoma not only unveils the intricate pathways and mechanisms underlying this devastating eye disease but also underscores the multifaceted dimensions that must be considered in its management.

This research aimed to compare the measurements recorded by a traditional PCI technology biometer (Partial Coherence Interferometry) and by a SS-OCT (Swept Source Optical Coherence Tomography) technology machine in preoperative screening of patients with age-related cataract. Optical biometry was performed with the IOLMaster 500 (version 5.5, Carl Zeiss Meditec, Germany) and the ANTERION (Heidelberg Engineering, Germany) in a total sample of 144 eyes, from 80 patients, (37 men and 43 women), with a mean age of 70.54 ± 0.739 years (range: 45-89 years) and the values of the Axial Length (AL), two meridians of the cornea (Kf, Kflat and Ks, Ksteep), astigmatism (Ast) as well as the Anterior Chamber Depth (ACD) were compared with the program IBM SPSS Statistics 27. The IOLMaster500 and ANTERION devices did not have statistically significant differences in terms of axial length and flat corneal meridian Kf, while they differed statistically significantly in terms of steep corneal meridian Ks, astigmatism and anterior chamber depth. This study suggests that a thorough pre-operative check must be performed, sometimes with more than one device, aiming at greater accuracy in the measurements of the ocular biometrics, so that we achieve more successful postoperative outcomes and ultimately more satisfied patients.

Purpose: To investigate the effect of fixed combination versus concomitant unfixed topical glaucoma treatment on patients’ adherence and ocular surface health. Patients and Methods: This is a 6-month, prospective, parallel-group, observational study in patients with ocular hypertension (OHT), primary open-angle glaucoma (POAG), or exfoliation glaucoma (XFG). A total of 142 patients with similar baseline characteristics were enrolled in this study. Seventy-one patients received a Latanoprost 0.005%/Timolol 0.5% fixed combination in the evening, whereas seventy-one patients received the unfixed treatment with Latanoprost 0.005% in the evening and Timolol 0.5% twice daily. The primary outcome was the adherence rate at baseline, and at the 3- and 6-month follow-up visits. The secondary outcomes included the signs of ocular surface disease (OSD) and intraocular pressure (IOP). Results: The adherence of patients treated with the fixed combination was higher than the unfixed treatment at the 3-month (78.0% vs. 63.0%, p < 0.001) and at the 6-month visits (73.0% vs. 58.5%, p < 0.01). The Break-up Time, Schirmer test, and Van Bijsterveld score were worse in the unfixed group at baseline and all subsequent examinations (p < 0.05 for all comparisons). There were no differences in the mean IOP between groups at baseline, 1-, and 3-month visits. IOP appears higher in the unfixed group at 6 months (16.7 vs. 15.0 mmHg, p < 0.01). Conclusion: The patients with ocular hypertension and primary open-angle glaucoma treated with a fixed combination are significantly more adherent and show a healthier ocular surface than those treated with an unfixed combination. The study provides significant evidence of the benefits of fixed combination treatment.

Purpose To assess the repeatability of corneal pachymetry and epithelial thickness measurements with spectral-domain optical coherence tomography (SD-OCT) and identify correlations between epithelial thickness and ocular surface parameters. Methods Adults who happened to have prolonged computer use were recruited, excluding those with conditions interfering with corneal measurements or tear production. All subjects filled in the ocular surface disease index (OSDI) questionnaire. Three consecutive measurements of central and peripheral corneal and epithelial thickness were performed with SD-OCT (RTVue XR). Schirmer test I and tear film break-up time (TBUT) were performed. Repeatability was evaluated with intraclass correlation coefficient (ICC), coefficient of variation and repeatability limit. Spearman correlation was used for non-parametric variables. Results 113 eyes of 63 subjects were included in the study. ICC was ≥ 0.989 for all corneal and ≥ 0.944 for all epithelial pachymetry segments. The best repeatability was found centrally and the worst superiorly both for corneal and epithelial measurements. Central epithelial thickness was weakly correlated with Schirmer test I (rho = 0.21), TBUT (rho = 0.02), OSDI symptoms and OSDI score (rho <|0.32|). OSDI symptoms and OSDI score were weakly correlated with Schirmer test I (rho <|0.3|) and TBUT (rho <|0.34|). Conclusion RTVue XR measurements of corneal and epithelial thickness are highly repeatable in all segments. The lack of correlation between epithelial thickness and ocular surface parameters could suggest the assessment of epithelial integrity with reliable methods such as SD-OCT.

Purpose To assess which cases should be assorted exclusively to high-volume surgeons and identify when should a cataract surgeon seek assistance from a senior colleague. Methods The medical records of 2853 patients with age-related cataract were reviewed. Preoperative risk factors were documented for each case, and they were divided into surgeons who had more (> 400 surgeries/year) or less experience (< 400 surgeries/year). Ophthalmology residents were excluded from this review. The cases that involved posterior capsule rupture, dropped nucleus, zonular dehiscence and anterior capsular tear with or without vitreous loss were defined as “complicated”. Results From the 3247 cataract extraction surgeries that were reviewed, we were unable to identify any statistically significant difference in the complication rates between the two surgeon groups. In the stepwise regression analysis, both groups supported advanced age (> 85) and mature cataracts with up to fourfold odds ratios (OR). Low-volume surgeons had a fivefold OR in the presence of phacodonesis and a fourfold OR in the case of posterior polar cataract. Finally, the low- and high-volume groups had their highest complication rates in the cumulative four and five risk factors, respectively. Conclusion In the presence of advanced age, mature cataracts, phacodonesis and posterior polar cataract, the complication rates appear to be higher for the less experienced surgeons. Meticulous preoperative assessment with detailed documentation of each patient’s risk factors can result in fewer complications. The medical complexity of each case can be used as indicator of whether a more experienced surgeon should perform the surgery or not.

Background Cataract surgery is a very popular operation that requires a postoperative period of frequent instillation of antibiotic and anti-inflammatory eye drops. Modified drug-eluting intraocular lenses (IOLs) may eliminate the need for eye drops after surgery. Aim The purpose of this study is to compare the morphological characteristics of dexamethasone eluting biodegradable polymeric thin films developed on the surface of commercially available IOLs by three different methods. Method This experimental study was conducted between May and August of 2021 in the Lab for Thin Films Nanobiomaterials Nanosystems & Nanometrology (LTFN) of the Aristotle University of Thessaloniki. A mixture of two organic polymers [Poly (D, L-lactide-co-glycolide)(PLGA), lactide: glycolide (75:25) and Polycaprolactone (PCL)] and dexamethasone was prepared and then deposited on the surface of three-piece IOLs by spin coating, by spray coating, and by gravure printing. The modified IOLs were sterilized with the use of ultraviolet (UV) radiation and plasma treatment. Their structural properties were studied with the use of atomic force microscopy (AFM). Results Spin coating and gravure printing produced uniform thin films on the surface of the IOLs which were not damaged during the sterilization process. Spray coating led to the partial coating of the surface of the IOLs; the thin films underwent alterations following plasma treatment. Conclusions Thin films developed by spin coating and gravure printing on IOLs demonstrate the desired morphological characteristics that make them suitable candidates for further research.