New disposable esthesiometer (KeraSenseⓇ) to improve diagnosis and management of neurotrophic keratitis.

PURPOSE: To validate the use, repeatability, and reproducibility of a new, cost-effective, disposable, sterile device (KeraSenseⓇ, Dompè farmaceutici SpA, Milan Italy) compared to Cochet-Bonnet (CB) esthesiometer. Secondly, to identify a simple, safe, rapid, and low-cost test to diagnose neurotrophic keratitis (NK). METHODS: 16 patients with diagnosis of NK stage I, 25 patients with diabetes mellitus (DM), and 26 healthy subjects were included in the study. Corneal sensitivity (CS) was assessed by CB and KeraSenseⓇ. Repeatability, accuracy, and reproducibility of the novel disposable aesthesiometer were assessed. Specificity, sensitivity, and cut-off value for NK diagnosis were calculated by ROC curve analysis. RESULTS: All NK patients showed a CS ≤ 40 mm, while none of the healthy patients showed a CS value < 50 mm. Significant agreement was found between CB measurements and the single use esthesiometer evaluations of CS (p < 0.001). Repeatability evaluations of the single use esthesiometer showed 100% agreement between different measurements (p < 0.001). Reproducibility evaluations showed 99.6% concordance between different operators (p < 0.001). A 55 mm value of the single use esthesiometer was adequate to exclude an NK diagnosis, while all NK patients showed a value ≤ 35 mm. CONCLUSIONS: Corneal hypo/anaesthesia is considered the hallmark of NK. The use of the novel single-use esthesiometer will allow for a diagnostic improvement in NK, sparing time and guaranteeing patients' safety. Diabetic patients despite normal corneal findings may show impairment of CS, suggesting a preclinical stage of NK, requiring a close follow-up.

Insights into Novel Choroidal and Retinal Clinical Signs in Neurofibromatosis Type 1.

Neurofibromatosis type 1 (NF1) is a rare inherited neurocutaneous disorder with a major impact on the skin, nervous system and eyes. The ocular diagnostic hallmarks of this disease include iris Lisch nodules, ocular and eyelid neurofibromas, eyelid café-au-lait spots and optic pathway gliomas (OPGs). In the last years, new manifestations have been identified in the ocular district in NF1 including choroidal abnormalities (CAs), hyperpigmented spots (HSs) and retinal vascular abnormalities (RVAs). Recent advances in multi-modality imaging in ophthalmology have allowed for the improved characterization of these clinical signs. Accordingly, CAs, easily detectable as bright patchy nodules on near-infrared imaging, have recently been added to the revised diagnostic criteria for NF1 due to their high specificity and sensitivity. Furthermore, subclinical alterations of the visual pathways, regardless of the presence of OPGs, have been recently described in NF1, with a primary role of neurofibromin in the myelination process. In this paper, we reviewed the latest progress in the understanding of choroidal and retinal abnormalities in NF1 patients. The clinical significance of the recently revised diagnostic criteria for NF1 is discussed along with new updates in molecular diagnosis. New insights into NF1-related neuro-ophthalmic manifestations are also provided based on electrophysiological and optical coherence tomography (OCT) studies.

Bilateral Angle Recession and Chronic Post-Traumatic Glaucoma: A Review of the Literature and a Case Report.

Ocular trauma affects millions of people worldwide and is a leading cause of secondary glaucoma. Angle recession is the main cause of post-traumatic glaucoma after blunt eye trauma, and it is usually unilateral. The aim of this paper is to investigate the possible causes of angle recession with a bilateral presentation. Airbag activation during traffic accidents is a likely cause to be ruled out, along with repeated head or eye trauma, due to contact sports or a history of physical abuse. These aspects can aid in early detection, appropriate management, and improved outcomes for patients with ocular trauma. Finally, we report the case of a 75-year-old Caucasian man who developed a bilateral angle recession after an airbag impact, with advanced glaucoma in the right eye and ocular hypertension in the left eye. To our knowledge, this is the first case in the literature of chronic post-traumatic glaucoma probably caused by an airbag.

Comparison between Cultivated Oral Mucosa and Ocular Surface Epithelia for COMET Patients Follow-Up.

Total bilateral Limbal Stem Cell Deficiency is a pathologic condition of the ocular surface due to the loss of corneal stem cells. Cultivated oral mucosa epithelial transplantation (COMET) is the only autologous successful treatment for this pathology in clinical application, although abnormal peripheric corneal vascularization often occurs. Properly characterizing the regenerated ocular surface is needed for a reliable follow-up. So far, the univocal identification of transplanted oral mucosa has been challenging. Previously proposed markers were shown to be co-expressed by different ocular surface epithelia in a homeostatic or perturbated environment. In this study, we compared the transcriptome profile of human oral mucosa, limbal and conjunctival cultured holoclones, identifying Paired Like Homeodomain 2 (PITX2) as a new marker that univocally distinguishes the transplanted oral tissue from the other epithelia. We validated PITX2 at RNA and protein levels to investigate 10-year follow-up corneal samples derived from a COMET-treated aniridic patient. Moreover, we found novel angiogenesis-related factors that were differentially expressed in the three epithelia and instrumental in explaining the neovascularization in COMET-treated patients. These results will support the follow-up analysis of patients transplanted with oral mucosa and provide new tools to understand the regeneration mechanism of transplanted corneas.

Does Patisiran Reduce Ocular Transthyretin Synthesis? A Pilot Study of Two Cases.

BACKGROUND: Variant transthyretin-mediated amyloidosis (ATTR-v) is a well-characterized disease affecting the neurologic and cardiovascular systems. Patisiran has been approved for neurologic involvement as it reduces hepatic synthesis of transthyretin (TTR). Eye involvement is a lateonset feature increasing the risk of glaucoma and cataracts in patients. AIMS: The aim of this case series was to assess whether patisiran can effectively reduce TTR synthesis in such a barrier-protected organ as the eye. METHODS: Two patisiran-treated ATTR-v patients underwent serum and aqueous humor sampling to measure TTR levels detected by SDS-PAGE and immunoblotting. Serum samples were compared to healthy control (HC), whereas aqueous humor samples were compared to non-amyloidotic subjects affected by cataracts and glaucoma. RESULTS: Serum TTR levels representative of hepatic synthesis were sharply lower in treated patients if compared to the HC (-87.5% and -93.75%, respectively). Aqueous humor TTR levels showed mild-tono reduction in treated patients compared to non-amyloidotic subjects with cataracts (-34.9% and +8.1%, respectively) and glaucoma (-41.1% and -2.1%). CONCLUSION: Patisiran does not seem to be as effective in inhibiting ocular TTR synthesis as it is in inhibiting hepatic synthesis. Re-engineering the envelope could allow the drug to target RPE cells thus avoiding any ocular involvement.

Psycho-Cognitive Profile and NGF and BDNF Levels in Tears and Serum: A Pilot Study in Patients with Graves' Disease.

Nerve Growth Factor (NGF) and Brain derived Neurotrophic Factor (BDNF) mature/precursor imbalance in tears and serum is suggested as a risk factor and symptomatology aggravation in ophthalmology and neuropsychiatric disturbances. Cognitive and mood alterations are reported by patients with Graves' Orbitopathy (GO), indicating neurotrophin alterations might be involved. To address this question, the expression levels of NGF and BDNF and their precursors in serum and tears of GO patients were analyzed and correlated with the ophthalmological and psycho-cognitive symptoms. Hamilton Rating Scale for Anxiety (HAM-A) and Depression (HAM-D), Temperament and Character Inventory (TCI), and Cambridge Neuropsychological Test Automated Battery (CANTAB) test were used as a score. NGF and BDNF levels were measured using ELISA and Western Blot and statistically analyzed for psychiatric/ocular variable trend association. GO patients show memorization time and level of distraction increase, together with high irritability and impulsiveness. HAM-A and CANTAB variables association, and some TCI dimensions are also found. NGF and BDNF expression correlates with ophthalmological symptoms only in tears, while mature/precursor NGF and BDNF correlate with the specific psycho-cognitive variables both in tears and serum. Our study is the first to show that changes in NGF and BDNF processing in tears and serum might profile ocular and cognitive alterations in patients.

Beta-Amyloid Peptide in Tears: An Early Diagnostic Marker of Alzheimer's Disease Correlated with Choroidal Thickness.

We aimed to evaluate the diagnostic role of Alzheimer's disease (AD) biomarkers in tears as well as their association with retinal and choroidal microstructures. In a cross-sectional study, 35 subjects (age 71.7 ± 6.9 years) were included: 11 with prodromal AD (MCI), 10 with mild-to-moderate AD, and 14 healthy controls. The diagnosis of AD and MCI was confirmed according to a complete neuropsychological evaluation and PET or MRI imaging. After tear sample collection, ß-amyloid peptide Aß1-42 concentration was analyzed using ELISA, whereas C-terminal fragments of the amyloid precursor protein (APP-CTF) and phosphorylated tau (p-tau) were assessed by Western blot. Retinal layers and choroidal thickness (CT) were acquired by spectral-domain optical coherence tomography (SD-OCT). Aß1-42 levels in tears were able to detect both MCI and AD patients with a specificity of 93% and a sensitivity of 81% (AUC = 0.91). Tear levels of Aß1-42 were lower, both in the MCI (p < 0.01) and in the AD group (p < 0.001) when compared to healthy controls. Further, Aß1-42 was correlated with psychometric scores (p < 0.001) and CT (p < 0.01). CT was thinner in the affected patients (p = 0.035). No differences were observed for APP-CTF and p-tau relative abundance in tears. Testing Aß1-42 levels in tears seems to be a minimally invasive, cost-saving method for early detection and diagnosis of AD.

Platelet-Rich Plasma (PRP) to promote corneal healing in firework-related ocular burn and total limbal stem cell deficiency (LSCD).

PURPOSE: To report the case of persistent corneal epithelial defect in total limbal stem cell deficiency (LSCD) after severe firework-related ocular burn treated with autologous Platelet-Rich Plasma (PRP). CASE DESCRIPTION: A young patient, victim of fireworks trauma, presented with a large persistent epithelial defect affecting the central cornea of his left eye and progressing to stromal melting, in the context of grade VI ocular surface burn with 12 h limbal involvement. Impression cytology to the cornea confirmed a complete LSCD. Assessment of corneal sensitivity by Cochet Bonnet esthesiometer revealed complete corneal anesthesia. Based on progressive clinical worsening under conventional therapy, the patient was started on very pure autologous PRP eye drops obtained using the Hy-Tissue PRP® technology. Six times a day eye drops administration for 30 days was scheduled in the affected eye. At the end of treatment, the epithelial defect had disappeared being replaced by advancing conjunctiva. CONCLUSION: Our findings provide information on management of ocular burns from fireworks, a subject of current interest and concern. Autologous PRP eye drops prepared using the Hy-Tissue PRP® system and administered in the presence of total LSCD and complete corneal anesthesia, prevented corneal stromal melting to progress and allowed the ocular surface epithelial coverage to re-establish. This paved the way for later successful restorative and reconstructive intervention. Also, first description of the Hy-tissue PRP procedure for ophthalmological use is reported.

Evaluation of the Effectiveness of BNT162b2 Primary Vaccination and Booster Dose to SARS-CoV-2 in Eliciting Stable Mucosal Immunity.

The waning effectiveness of the primary vaccination for SARS-CoV-2 led to administration of an additional booster dose (BD). The efficacy of the BD in stimulating humoral systemic immune response is well established, but its effectiveness on inducing mucosal immune reaction has not yet been reported. To address this issue, we evaluated SARS-CoV-2-specific antibody responses in the serum, saliva, and tears after BNT162b2 (Pfizer/BioNTech, New York, NY, USA) vaccination and BD, as well as after SARS-CoV-2 infection. After two doses of BNT162b2 vaccine, we observed specific serum IgG in 100% and IgA in 97.2% of subjects, associated with mucosal response in both salivary samples (sIgA in 97.2% and IgG(S) in 58.8%) and in tears (sIgA in 77.8% and IgG(S) in 67.7%). BD induced a recovery of the systemic humoral response and of tear sIgA when compared to 6 months of follow-up titers (p < 0.001; p = 0.012). However, sIgA levels in both tears and saliva were significantly lower following BD when compared to patients with prior SARS-CoV-2 infection (p = 0.001 and p = 0.005, respectively). Our results demonstrated that administration of BD restored high serum levels of both IgG and IgA but had a poor effect in stimulating mucosal immunity when compared to prior SARS-CoV-2 infection.

NGF Prevents Loss of TrkA/VEGFR2 Cells, and VEGF Isoform Dysregulation in the Retina of Adult Diabetic Rats.

Among the factors involved in diabetic retinopathy (DR), nerve growth factor (NGF) and vascular endothelial growth factor A (VEGFA) have been shown to affect both neuronal survival and vascular function, suggesting that their crosstalk might influence DR outcomes. To address this question, the administration of eye drops containing NGF (ed-NGF) to adult Sprague Dawley rats receiving streptozotocin (STZ) intraperitoneal injection was used as an experimental paradigm to investigate NGF modulation of VEGFA and its receptor VEGFR2 expression. We show that ed-NGF treatment prevents the histological and vascular alterations in STZ retina, VEGFR2 expression decreased in GCL and INL, and preserved the co-expression of VEGFR2 and NGF-tropomyosin-related kinase A (TrkA) receptor in retinal ganglion cells (RGCs). The WB analysis confirmed the NGF effect on VEGFR2 expression and activation, and showed a recovery of VEGF isoform dysregulation by suppressing STZ-induced VEGFA121 expression. Reduction in inflammatory and pro-apoptotic intracellular signals were also found in STZ+NGF retina. These findings suggest that ed-NGF administration might favor neuroretina protection, and in turn counteract the vascular impairment by regulating VEGFR2 and/or VEGFA isoform expression during the early stages of the disease. The possibility that an increase in the NGF availability might contribute to the switch from the proangiogenic/apoptotic to the neuroprotective action of VEGF is discussed.

Oxidative Stress Implication in Retinal Diseases-A Review.

Oxidative stress (OS) refers to an imbalance between free radicals (FRs), namely highly reactive molecules normally generated in our body by several pathways, and intrinsic antioxidant capacity. When FR levels overwhelm intrinsic antioxidant defenses, OS occurs, inducing a series of downstream chemical reactions. Both reactive oxygen species (ROS) and reactive nitrogen species (RNS) are produced by numerous chemical reactions that take place in tissues and organs and are then eliminated by antioxidant molecules. In particular, the scientific literature focuses more on ROS participation in the pathogenesis of diseases than on the role played by RNS. By its very nature, the eye is highly exposed to ultraviolet radiation (UVR), which is directly responsible for increased OS. In this review, we aimed to focus on the retinal damage caused by ROS/RNS and the related retinal pathologies. A deeper understanding of the role of oxidative and nitrosative stress in retinal damage is needed in order to develop targeted therapeutic interventions to slow these pathologies.

Topical nerve growth factor prevents neurodegenerative and vascular stages of diabetic retinopathy.

Specific and effective preventive treatment for diabetic retinopathy (DR) is presently unavailable, mostly because the early stages of the complication have been, until recently, poorly understood. The recent demonstration that the vascular phase of DR is preceded and possibly caused by the neurodegeneration of retinal ganglion cells suggests that DR could, at least theoretically, be prevented through an early neuroprotective approach. The aims of our study were to clarify the natural history of diabetes-driven retinal neurodegeneration and to verify the possibility to prevent DR using topical nerve growth factor (NGF). The results of the study show that retinal neurodegeneration, characterized by the loss of retinal ganglion cells represents a relatively early phenomenon of diabetes (between 5 and 16 weeks of age), which tends to be self-limiting in the long run. Neurodegeneration is followed by the development of DR-related vascular dysfunctions, as confirmed by the development of acellular capillaries and the loss of retinal pericytes. Both retinal neurodegeneration and subsequent vascular dysfunction can be successfully prevented by topical NGF administration. These findings suggest that: 1) The first stage of DR consists in a self-limiting retinal neurodegeneration 2) The demonstrated effectiveness of topical NGF in the prevention of DR could be rapidly translated into clinical practice.

An update on choroidal abnormalities and retinal microvascular changes in neurofibromatosis type 1.

Neurofibromatosis Type 1 (NF1) is a rare neurocutaneous disorder transmitted in an autosomal dominant fashion, mainly affecting the nervous system, the eye and skin. Ocular diagnostic hallmarks of NF1 include iris Lisch nodules, optic gliomas, orbital and eyelid neurofibromas, eyelid café-au-lait spots. In recent years, a new ocular sign represented by choroidal abnormalities (CAs) has been characterized in NF1. The CAs, identified with near-infrared reflectance, have been reported with a frequency of up to 100% in NF1, and have recently been added to the actual diagnostic criteria for NF1. The present Letter to the journal is intended to provide an update on features and clinical significance of CAs in NF1. Moreover, the relation with other ocular manifestations recently described in NF1 including hyperpigmented spots and retinal microvascular abnormalities is discussed.

Benralizumab reduces eosinophils and inflammatory markers in patients with severe eosinophilic asthma and chronic rhinosinusitis with nasal polyps: A pilot real-life study.

Chronic rhinosinusitis with nasal polyps (CRSwNP) and Severe Eosinophilic Asthma (SEA) are both frequently sustained by eosinophilic inflammation and are probably the manifestation of a unique disease of upper and lower respiratory tract. We retrospectively observed 11 patients with severe CRSwNP and concomitant SEA under add-on therapy with benralizumab evaluating symptoms using Sino Nasal Outcome Test-22 (SNOT-22), Visual Analogue Scale (VAS), and Asthma Control Test (ACT) and Nasal polyp size by endoscopic and radiological score by Nasal Polyp Score (NPS) and Lund-Mackay Score (LMS). At 6 and 12 months, the expression of cationic eosinophil protein (ECP), Interleukin 17 (IL-17), Interferon gamma (INF-γ), and vascular endothelial growth factor (VEGF) was measured by nasal scraping to assess mucosal inflammation. After 12 months of benralizumab treatment, SNOT-22 decreased from 45 (23-97) to 14 (5-53) (p < 0.05), total VAS of rhinologic symptoms decreased from 30 (17-44) to 9 (5-37) (p ≤ 0.01) and ACT score increased from 10 (5-15) to 24 (20-25) (p ≤ 0.01). NPS decreased from 5 (3-6) to 3 (2-4) after 6 months (p < 0.05) and to 2 (2-3) after one year respectively (p <  0.05) and LMS total score from 21 (15-24) to 17 (8-21) (p ≤ 0.01) after 12 months from starting treatment. Nasal mucosa scraping found differences in INF-γ and VEGF expression in patients compared to 10 healthy subjects, with a normalization of these markers during eosinophils depletion induced by benralizumab. This is the first pilot real-life study conducted with an anti-IL5R monoclonal antibody in severe eosinophilic asthma and severe CRSwNP patients showing that this treatment can induce benefit both diseases not only from the clinical, but also from the inflammatory point of view. Moreover, our research pointed out that INF-γ and VEGF may represent potential response biomarker.

SOX2 Is a Univocal Marker for Human Oral Mucosa Epithelium Useful in Post-COMET Patient Characterization.

Total bilateral Limbal Stem Cells Deficiency is a pathologic condition of the ocular surface due to loss or impairment of corneal stem cell function, altering homeostasis of the corneal epithelium. Cultivated Oral Mucosa Epithelial Transplantation (COMET) is the only autologous treatment for this pathology. During the follow-up, a proper characterization of the transplanted oral mucosa on the ocular surface supports understanding the regenerative process. The previously proposed markers for oral mucosa identification (e.g., keratins 3 and 13) are co-expressed by corneal and conjunctival epithelia. Here, we propose a new specific marker to distinguish human oral mucosa from the epithelia of the ocular surface. We compared the transcriptome of holoclones (stem cells) from the human oral mucosa, limbal and conjunctival cultures by microarray assay. High expression of SOX2 identified the oral mucosa vs. cornea and conjunctiva, while PAX6 was highly expressed in corneal and conjunctival epithelia. The transcripts were validated by qPCR, and immunological methods identified the related proteins. Finally, the proposed markers were used to analyze a 10-year follow-up aniridic patient treated by COMET. These findings will support the follow-up analysis of COMET treated patients and help to shed light on the mechanism of corneal repair and regeneration.

Neuroretinal dysfunction in patients affected by neurofibromatosis type 1.

AIM: To examine neuroretinal function by using the multifocal electroretinography (mfERG) test in patients with neurofibromatosis type 1 (NF1) without optic pathway gliomas (OPGs). METHODS: This study was conducted on 35 patients (35 eyes) with NF1 and 30 healthy subjects (30 eyes) for the control group. Each subject underwent a complete ophthalmological examination including spectral domain-optical coherence tomography (SD-OCT) and mfERG. The 1.5-Tesla magnetic resonance imaging (MRI) scan of the brain was performed in NF1 patients to assess the presence of OPGs. All participants were recruited having a best corrected visual acuity (BCVA) of no less than 20/20 in each eye. The amplitude and implicit time of the P1 wave (first-order Kernel component) were evaluated on mfERG. Data analysis was carried out in the two central degrees and in the four quadrants from two to 25 degrees of visual field. RESULTS: Statistically significant results were obtained for the P1 wave amplitudes in the 4 quadrants in NF1 patients compared to healthy controls, while the reduction was not significant in the 2 central degrees between the groups. A statistically significant difference was observed among the P1 wave amplitudes as recorded in the 4 quadrants within the NF1 group, with lower amplitudes detected in the nasal quadrants. No differences in the implicit times were recorded in the 2 central degrees and in the 4 quadrants as compared between NF1 patients and controls. CONCLUSION: Impaired neuroretinal function in NF1 patients is expressed in a decreased amplitude of the P1-wave between 2 and 25 central retinal degrees on mfERG. Altered intracellular signal transduction due to abnormal neurofibromin-mediated cyclic adenosine monophosphate (cAMP) generation, can be involved. The possible use of mfERG as subclinical retinal damage indicator has a potential utility in clinical practice for the follow-up of NF1 patients.

Topical treatment of dupilumab-associated refractory conjunctivitis and keratitis.

PURPOSE: To report 3 cases of severe dupilumab-related conjunctivitis and keratitis topical treatment. OBSERVATION: Description, management, and outcomes of dupilumab-related refractory conjunctivitis associated with punctate keratitis.Three patients with atopic dermatitis (AD) experiencing severe ophthalmic complications following dupilumab treatment were referred to us when conventional management methods failed. We treated them topical and external pimecrolimus 10 mg/g cream to the eyelids. The patients showed substantial clinical remission within 10 days. CONCLUSIONS AND IMPORTANCE: Those cases are remarkable as a drug applied externally to the eyelid skin successfully treated underlying conjunctivitis and punctate keratitis. The complete clinical remission suggests that pimecrolimus applied topically to the eyelid skin is a safe and effective delivery route. The resolution of the keratitis and conjunctivitis presumably represents either a contiguous effect of the improvement of the cutaneous inflammation, or the effect of transcutaneous pimecrolimus penetration through the eyelid.Further studies are needed to support the use of this drug for dupilumab-associated conjunctivitis.

Long-term clinical efficacy of topical treatment with recombinant human nerve growth factor in neurotrophic keratopathy: a novel cure for a rare degenerative corneal disease?

BACKGROUND: Neurotrophic keratopathy (NK) is a rare, degenerative ocular disease characterized by reduction or loss of corneal sensitivity and development of non-healing corneal epithelial defects and ulcers. Cenegermin, a recombinant human nerve growth factor (rhNGF) eye drop solution, is the first drug approved for the treatment of NK. The aim of our study is to evaluate the long-term efficacy of this innovative topical treatment in patients with NK. METHODS: Retrospective, consecutive, observational case series study from a single-center setting (Department of Sense Organs, University Sapienza of Rome, Rome, Italy). 18 patients with diagnosis of stage 2 or 3 NK, treated with Cenegermin 20 mcg/ml eye drops were followed for up to 48 months. Recurrence of lesion during follow-up was evaluated at 12, 24, 36, and 48 months. In addition, corneal sensitivity, Schirmer tear test, and visual acuity (VA) were recorded at baseline, end of treatment, and at 12, 24, 36, and 48 months. RESULTS: Three patients experienced recurrence of persistent epithelial defects (PEDs) within 12 months and one patient experienced recurrence of a corneal ulcer within 36 months. Corneal sensitivity was significantly improved at all timepoints (P < 0.05). Significant improvements in visual acuity and tear production were seen at the completion of treatment as well as at 12, 24, and 36 months (P < 0.05) when compared to baseline. CONCLUSIONS: A single 8-week treatment regimen of Cenegermin eye drops has clinical efficacy that can persist for up to 48 months. The long-term clinical utility of treatment with Cenegermin for NK was demonstrated through the low rate of lesion recurrence along with improvements in corneal sensitivity and tear production.

Complement Mediators in Development to Treat Age-Related Macular Degeneration.

Over recent years, great attention has been paid to the role of the complement system in the pathogenesis of age-related macular degeneration (AMD). In particular, several studies have highlighted a link between AMD development and complement dysregulation, which can probably be explained as a complement cascade hyperactivation resulting from the presence of a series of risk factors such as aging; smoking; obesity; alcohol consumption; exposure to pesticides, industrial chemicals, or pollution; and other causes of oxidative stress. This hypothesis has been mainly supported by the presence of complement mediators as constituents of drusen, representing one of the earliest and most characteristic signs of retinal damage in AMD. Additionally, activated complement mediators and some complement regulators, such as vitronectin, have been found not only in the drusen and adjacent retinal areas but also in the peripheral blood of patients with AMD. Therefore, we aim to provide a review of recently studied complement factors to highlight their role in the pathogenesis of AMD and to evaluate new potential therapeutic strategies.