Andrea Maria Plateroti

Curcumin: Therapeutical Potential in Ophthalmology

Curcumin (diferuloylmethane) is the main curcuminoid of the popular Indian spice turmeric (Curcuma longa). In the last 50 years, in vitro and in vivo experiments supported the main role of polyphenols and curcumin for the prevention and treatment of many different inflammatory diseases and tumors.The anti-inflammatory, antioxidant, and antitumor properties of curcumin are due to different cellular mechanisms: this compound, in fact, produces different responses in different cell types. Unfortunately, because of its low solubility and oral bioavailability, the biomedical potential of curcumin is not easy to exploit; for this reason more attention has been given to nanoparticles and liposomes, which are able to improve curcumins bioavailability. Pharmacologically, curcumin does not show any dose-limiting toxicity when it is administered at doses of up to 8 g/day for three months. It has been demonstrated that curcumin has beneficial effects on several ocular diseases, such as chronic anterior uveitis, diabetic retinopathy, glaucoma, age-related macular degeneration, and dry eye syndrome. The purpose of this review is to report what has so far been elucidated about curcumin properties and its potential use in ophthalmology.

Morphologic and vasculature features of the choroid and associated choroid–retinal thickness alterations in neurofibromatosis type 1

Background/aims A normal structural and functional choroid is essential in supplying blood flow to the retina. Neurofibromatosis type 1 (NF1) is a neurocristopathy where the choroid is altered due to the presence of nodules. The present transversal study was conducted to examine choroidal nodules and their effect on choroidal and retinal thickness in NF1 patients. Methods Near-infrared reflectance and optical coherence tomography with enhanced depth imaging were used to evaluate choroidal morphology and vasculature in 19 patients with NF1 and 19 healthy, age-matched control subjects. Choroidal thickness, neuroepithelium thickness, photoreceptors together with retinal pigment epithelium (RPE) thickness and outer nuclear layer (ONL) thickness were measured at the fovea and 1000 μm nasal, temporal, superior and inferior to the fovea in NF1 patients and control subjects. Choroidal and neuroepithelium thickness were assessed overlying and adjacent to nodules in NF1 patients. Results Choroidal nodules were classified as ‘dome-shaped’ or ‘placcoid’ subtypes in 17 patients. Small and medium calibre choroidal vessels were observed above dome-shaped nodules where choroidal thickness was significantly reduced. There was a statistically significant reduction in mean choroidal thickness (p=0.013) in NF1 patients with respect to control subjects. The neuroepithelium, photoreceptors together with RPE and ONL had a statistically significant reduction in mean thickness in NF1 patients (p<0.001, p<0.001, p=0.012, respectively). Conclusions In NF1, there are dome-shaped and placcoid choroidal nodules which alter choroidal morphology and thickness. There is reduction in mean choroid thickness with generalised thinning of the neuroepithelium, photoreceptors together with RPE and ONL in NF1 patients.

Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma: A Review of the Literature with Updates on Surgical Management

Pseudoexfoliation syndrome (PES) is a systemic disorder caused by progressive accumulation of extracellular material over various tissues. PES usually determines increased intraocular pressure, changes in the anatomical aspects of the optic nerve, and visual field alterations leading to the diagnosis of pseudoexfoliation glaucoma (PEG). Use of topical medical treatment usually leads to poor results in terms of long-term follow-up but many surgical techniques, such as Argon Laser or Selective Laser Trabeculoplasty, have been proposed for the management of PEG affected patients. The present paper is a review on the pseudoexfoliation syndrome and pseudoexfoliation glaucoma with an update on surgical management.

Potential regulatory molecules in the human trabecular meshwork of patients with glaucoma: Immunohistochemical profile of a number of inflammatory cytokines

Glaucoma occurs when there are imbalances between the production and the drainage of the eye liquid. The vast majority of the aqueous humor leaves the eye through the trabecular meshwork (TM). The cause of hypertonicity may be due to an alteration in the thickness of the TM. In the majority of cases the molecular changes that determine primary open‑angle glaucoma (POAG) are unclear. However, it has been hypothesized that the significant increase in the extracellular matrix (ECM) of the fibrillary bands in the TM is associated with possible inflammatory conditions. In this study the tissue distribution of interleukin (IL)‑6, IL‑1β, transforming growth factor-β1 (TGF‑β1), vascular endothelial growth factor (VEGF) and tumor necrosis factor α (TNF‑α) was analyzed in TM samples from patients with POAG by immunohistochemistry. Seven specimens from patients with POAG and three control tissues were analyzed by immunohistochemistry using specific antibodies against these cytokines. Morphological changes in the TM, such as increased cell content, macrophages, fibrosis and accumulation of neutrophils, were observed by transmission electron microscopy. In human TM tissues, an evident immunoreactivity for IL‑6, IL‑1β and TNF‑α was observed in patients with POAG when compared with the control subjects, indicating that these cytokines may be correlated with disease activity. TM endothelial cells secrete a number of factors and cytokines that modulate the functions of the cells and the ECM of the conventional outflow pathway. In the TM in glaucoma, macrophages produce cytokines, including IL‑6, IL‑1β and TNF‑α, leading to an acute inflammatory response and recruitment of other immune cells, including T lymphocytes. In addition, TGF‑β1 regulates and induces the expression of IL‑6 in TM that indirectly induces angiogenesis by stimulating VEGF expression. The present results support previous evidence that suggests that growth factors and cytokines can induce ECM remodelling and alter cytoskeletal interactions in the TM.

SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY EVIDENCE OF RETINAL NERVE FIBER LAYER AND GANGLION CELL LOSS IN ADULT PATIENTS WITH NEUROFIBROMATOSIS TYPE 1.

Purpose: To evaluate peripapillary retinal nerve fiber layer, macular retinal nerve fiber layer, and ganglion cell layer–inner plexiform layer thickness and analyze their correlations in adult patients with neurofibromatosis Type 1 (NF1) and disease-free controls. Methods: This cross-sectional study was performed at the Azienda Policlinico Umberto I, University of Rome “La Sapienza.” All participants underwent complete ophthalmologic examination. Spectral domain optical coherence tomography was used to evaluate peripapillary retinal nerve fiber layer and obtain retinal segmentation measurements to assess macular retinal nerve fiber layer and ganglion cell layer–inner plexiform layer at 1,000 &mgr;m nasal, temporal, superior, and inferior to the fovea. Results: Thirty-four eyes of 17 patients with NF1 (mean age, 42.2 ± 14.3 years) and 34 eyes of 17 disease-free control subjects (mean age, 41.4 ± 12.2 years) were included. All participants had best-corrected visual acuity of 20/20. The mean thickness of peripapillary retinal nerve fiber layer, macular retinal nerve fiber layer, and ganglion cell layer–inner plexiform layer was lower in patients with NF1 with respect to controls (P = 0.003, P = 0.022, P < 0.001, respectively). Regression analysis showed a significant correlation (P < 0.001) between mean ganglion cell layer–inner plexiform layer thickness and mean peripapillary retinal nerve fiber layer thickness in patients with NF1. Conclusion: Retinal nerve fiber layer and ganglion cell loss correlate well with each other in adult patients with NF1 in comparison with a healthy control population.

Role of the Dopaminergic System in the Development of Myopia in Children and Adolescents

This review summarizes the experimental evidence that supports the role of dopamine in the regulation of ocular axial growth. The most important functions attributed to dopamine are light adaptation and regulation of the retinal circadian rhythm. An increase of the retinal levels of dopamine activates D1 and D2 dopaminergic receptors present throughout the retina, generating a signal that inhibits axial growth once the eye has reached emmetropization. Researchers induced form-deprivation myopia in animal models in order to assess the different changes of ocular axial growth. Other studies have shown that phenylethylamine is an endogenous precursor-neurotransmitter capable of modulating the activity of dopamine. Considering the role of the dopaminergic system in the development of myopia (in children and adolescents) and the fact that phenylethylamine improves the consequences of a dopamine deficit, it would be interesting to study the effect of phenylethylamine on the regulation of axial growth, which represents the genesis of myopia.

Investigation of pepsin in tears of children with laryngopharyngeal reflux disease

OBJECTIVES Numerous investigations postulated that laryngopharyngeal reflux (LPR) is implicated in the pathogenesis of various upper airway inflammatory diseases as sinusitis or dacryostenosis. The presence of pepsin in tears might be confirmed the presuntive hypothesis of the arrival in the nasolacrimal ducts and precorneal tears film through the laryngopharyngeal reflux of either gastric acid or stomach secretions (pepsin) with inflammatory potentialities. The aim of this preliminary study was to identify the presence or absence of pepsin in the tears collected from children with a high suspicion of LPR who underwent 24-h pH (MII-pH) monitoring to confirm the disease. METHODS This study enrolled 20 patients suffering from symptoms of laryngopharyngeal reflux that underwent 24-h multichannel intraluminal impedance (MII)-pH monitoring to confirm the disease. The findings of the study group were compared with those of a control group of patients with negative pH monitoring. The quantitative analysis of human pepsin concentration in the tear samples was performed by ELISA method in both groups. RESULTS Four children (20%) of the study group showed pepsin in the tears. All of the subjects belonging to the control group were negative for its presence. No difference differences in the total number of reflux episodes and the number of weakly basic reflux in the pepsin positive patients vs. pepsin negative children were present. CONCLUSIONS 20% of the children with diagnosed LPR showed pepsin in the tears. Our specific investigation might provide information regarding sinusitis or dacryostenosis.

Gastroesophageal reflux disease and the presence of pepsin in the tears.

The nasolacrimal duct in association with the lacrimal puncta, lacrimal canaliculi and lacrimal sac functions to collect and drain the tear film into the nasal cavity at the inferior nasal meatus where a fold of nasal mucosa, the so-called valve of Hasner, prevents mucous from entering the nose. High-resolution computed tomography demonstrated air inside the sac and nasolacrimal duct in approximately 29.3% of healthy patients suggesting that the system is not completely competent and that air and secretions might reach the precorneal film. Gastroesophageal reflux disease may contribute to dacryostenosis and subsequent primary acquired nasolacrimal duct obstruction. However a cause-effect relationship is unclear and only presumptive unless the presence of pepsin in tears can be demonstrated. Gastroesophageal and extra-esophageal reflux could reach the tear film via the nasolacrimal duct in a retrograde fashion and the middle ear via the Eustachian tube. We postulated that the ascending products of gastroesophageal reflux could cause edema of the nasolacrimal duct mucosa, which might progress to fibrosis and chronic inflammation and, ultimately, complete obstruction of the duct with epiphora. The role of reflux in the initial phase of this pathophysiological mechanisms could be demonstrated indirectly by pepsin. By contrast, the development of dacryostenosis blocking the passage of the nasolacrimal duct and thereby preventing pepsin from reaching the lacrimal film failed to explain the influence of gastroesophageal reflux disease with certainty.

An Update on the Ophthalmologic Features in the Phakomatoses

Neurofibromatosis type 1, tuberous sclerosis complex, and Von Hippel-Lindau disease, historically classified as the phakomatoses, are hereditary multisystem disorders characterized by the presence of hamartoma, which carry the risk of malignant transformation. The alteration of tumor suppressor genes seems to be at the basis of their pathophysiogenetic mechanism. Lisch and choroidal nodules in neurofibromatosis type 1, retinal astrocytomas in tuberous sclerosis complex, and retinal capillary hemangioma in Von Hippel-Lindau disease are the principal ophthalmic hamartomatous manifestations. The advent of novel imaging techniques such as near infrared reflectance and optical coherence tomography has provided unprecedented insight on the choroidal and retinal features of these diseases. These methods have improved early diagnosis and the ongoing surveillance in these conditions. Among an array of treatment modalities, antivascular endothelial growth factor therapy has been used in the management of retinal hamartomas but results have been varied. This review is an update on the pathophysiogenetic mechanisms, ophthalmic manifestations, and novel treatment strategies in the phakomatoses with emphasis on the role of imaging techniques.

Iatrogenic dry eye disease: An eledoisin/carnitine and osmolyte drops study

BACKGROUND To evaluate the effects of an eye drop containing eledoisin and carnitine in patients suffering from primary open-angle glaucoma (POAG) and ocular discomfort syndrome secondary to a chronically treated with eye drops containing benzalkonium chloride (BAK) as preservative. The dry eye disease was defined as a multifactorial drop disease concerning tears and ocular surface, which brings to discomfort symptoms and visual disorders with potential damage to the ocular surface. Several studies underlined the beneficial effects of secretagogues drugs, such as eledoisin. It is a neuro-peptide extracted from the salivary glands of some shellfishes. Recently, it has been also showed the protective role of carnitine in respect of the ocular surface exposed to the tear film hyperosmolarity. MATERIALS AND METHODS This randomized double-blind pilot study has been evaluated by lubricant eye drop solutions containing eledoisin and carnitine in 40 patients with ocular discomfort syndrome secondary to POAG, since that the patients were chronically treated with eye drops which decrease eye pressure and contain BAK as preservative. The subjects filled out a questions form concerning the severity of the symptoms and their impact on daily activities. Subsequently Fluorescein Breakup Time (FBUT), Schirmer Test 1 (ST), and Ocular Protection Index (OPI) were measured at baseline and after 15days of treatment. RESULTS At the end of therapy it was possible to match the beneficial effects of eye drops with carnitin, taurine, sodium hyaluronate and eledoisin. In fact, after 15days of treatment, patients of group 1 showed a decrease of approximately 50% concerning the severity of symptoms and a significant improvement of the tests valued. CONCLUSION In summary, lubricant eye drops that restore physiological hosmolarity and stimulate tear production represent a promising strategy for dry eye syndrome.