Rocco Plateroti

Immunohistochemical Profile and VEGF, TGF-β and PGE2 in Human Pterygium and Normal Conjunctiva: Experimental Study and Review of the Literature

Human pterygium is made up of chronic proliferative fibro-vascular tissue growing on the ocular surface. This disease exhibits both degenerative and hyperplastic properties. Some fibroangiogenic factors have recently been shown to play a potential role in fibrovascular diseases via the angiogenesis process. The aim of this study is to evaluate VEGF, TGF-β and PGE2 expression in the epithelial, endothelial and stromal cells of human pterygium and normal conjunctiva in order to determine whether these factors participate in the development of pterygium. Ten specimens from patients with pterygium and two normal conjunctivas (cadavers) were analyzed by immunohistochemistry using specific antibodies against these growth factors. The technique used was ABC/HRP (Avidin complexed with biotinylated peroxidase). Immunoreactivity of VEGF was significantly increased in the epithelium, vascular endothelium and stromal cells in primary pterygium as compared with normal conjunctiva. A moderate expression of TGF-β in the pterygium was observed in the epithelial and stromal layers. On the contrary, immunolabeling of this growth factor in the human normal conjunctiva was weak. PGE2 was strongly expressed in the epithelium of patients with pterygium, as in control conjunctival tissues, and the immunolabeling was moderate in the stroma from the same patients. Our results suggest that these growth factors may contribute to the progression of primary pterygium by increasing angiogenesis, thus leading to the formation of new blood vessels from the pre-existing vasculature. We conclude that VEGF, TGF-β and PGE2 may be potential therapeutic targets in the treatment of this disease although proof of this evidence requires further studies.

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.

Age and diabetes related changes of the retinal capillaries: An ultrastructural and immunohistochemical study

Normal human aging and diabetes are associated with a gradual decrease of cerebral flow in the brain with changes in vascular architecture. Thickening of the capillary basement membrane and microvascular fibrosis are evident in the central nervous system of elderly and diabetic patients. Current findings assign a primary role to endothelial dysfunction as a cause of basement membrane (BM) thickening, while retinal alterations are considered to be a secondary cause of either ischemia or exudation. The aim of this study was to reveal any initial retinal alterations and variations in the BM of retinal capillaries during diabetes and aging as compared to healthy controls. Moreover, we investigated the potential role of vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines in diabetic retina. Transmission electron microscopy (TEM) was performed on 46 enucleated human eyes with particular attention to alterations of the retinal capillary wall and Müller glial cells. Inflammatory cytokines expression in the retina was investigated by immunohistochemistry. Our electron microscopy findings demonstrated that thickening of the BM begins primarily at the level of the glial side of the retina during aging and diabetes. The Müller cells showed numerous cytoplasmic endosomes and highly electron-dense lysosomes which surrounded the retinal capillaries. Our study is the first to present morphological evidence that Müller cells start to deposit excessive BM material in retinal capillaries during aging and diabetes. Our results confirm the induction of pro-inflammatory cytokines TNF-α and IL-1β within the retina as a result of diabetes. These observations strongly suggest that inflammatory cytokines and changes in the metabolism of Müller glial cells rather than changes in of endothelial cells may play a primary role in the alteration of retinal capillaries BM during aging and diabetes.

Retinitis pigmentosa: evaluation of the vestibular system with cervical and ocular vestibular evoked myogenic potentials and the video head impulse test.

Objective Retinitis pigmentosa (RP) represents a group of inherited disorders in which abnormalities of the photoreceptors lead to progressive visual loss. Night blindness, peripheral visual field loss, and eventual total blindness represent typical visual damage of such disease. No study has previously evaluated the presence of a “latent” vestibular deficit in patients with RP. Study Design Prospective study with caloric test, cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and video head impulse test (v-HIT). Setting Tertiary referral center. Patients 16 patients suffering from RP. Intervention Evaluation of vestibular dysfunction with caloric test, C-VEMPs, O-VEMPs, and the measurement of the vestibular-ocular reflex (VOR) using the v-HIT. Results Only five patients with RP showed normal values in all the vestibular tests performed. Three patients had an evident deficit at the caloric test, whereas eight (50%) of them had a normal caloric test but a pathological response in at least one of the other vestibular tests performed. No patient of the study showed a bilateral otolith or ampullary dysfunction. Conclusion Our patients with RP unexpectedly showed pathological responses in at least one of the vestibular tests performed. Nowadays, in patients affected by RP, a vestibular diagnostic protocol must include VEMPs and v-HIT to confirm the vestibular damage and to identify selective damage of the vestibular nerve.

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.

Irritable eye syndrome: neuroimmune mechanisms and benefits of selected nutrients.

Previous studies showed comorbidity of some ocular, enteral, and affective symptoms comprising irritable eye syndrome. Aims of the present study were to learn more about the pathogenic mechanisms of this syndrome and to evaluate benefits of food supplements on these disorders. In in vitro assay, Lactobacillus acidophilus lysate inhibited interleukin (IL)-1β and tumor necrosis factor (TNF)-α generation of lipopolysaccharide (LPS)-stimulated macrophages in dose- and size-dependent manner. For a prospective, open-label phase I/II controlled clinical trial, 40 subjects affected by ocular dysesthesia and hyperesthesia and comorbid enteral and anxiety-depression symptoms were randomly assigned either into the treated group, which received a composition containing probiotic lysate, vitamins A, B, and D and omega 3 fatty acids, or into the control group, which received vitamins and omega 3 fatty acids. For reference, 20 age- and sex-matched healthy subjects were also selected. White blood count (WBC) and lymphocyte and monocyte counts, as well as IL-6 and TNF-α levels, were significantly above the reference levels in both treated and control groups. After 8 weeks, WBC and lymphocyte and monocyte counts, and cytokine levels significantly decreased, and ocular, enteral, and anxiety-depression symptoms significantly improved in the treated group as compared to the control group. This proof-of-concept study suggested that subclinical inflammation may be a common mechanism connecting ocular, enteral, and anxiety/depression symptoms, and supplements affecting dysbiosis may be a new approach to treating this syndrome.

An Update on Oculodermal Melanocytosis and Rare Associated Conditions

Abstract Oculodermal melanocytosis (ODM) is a rare disease, which is characterized by hyperpigmentation of facial skin and several parts of the eye, such as the sclera, conjunctiva, cornea, iris, ciliary body, and choroid. The condition usually affects the Asian female population. The most typical presenting ocular sign is iris heterocromia. Iris hyperpigmentation may be associated with iris mammillations, which are dome-shaped protuberations of the iris surface. They are linked to a higher risk of malignant transformation when present in patients with ODM. Glaucoma is a complication of ODM and is caused by angle abnormalities or mechanical occlusion by melanocytes in an open irido-corneal angle. Choroidal and ciliary body melanoma have a higher incidence in this condition characterized by melanocytosis. Patients presenting ODM should undergo routine ophthalmological examination in order to carefully monitor for glaucoma and melanoma.

Histological findings in a failed corneal riboflavin-UVA collagen cross-linking performed for progressive keratoconus.

Purpose: To report the histological and immunohistochemical findings in a cornea removed from a patient who had undergone collagen cross-linking (CXL) with riboflavin and ultraviolet-A for progressive keratoconus. CXL was performed following the Siena protocol. Two years post-CXL, a visual acuity impairment in the treated eye secondary to corneal stromal opacity had occurred, together with corneal thinning and flattening. Methods: The excised cornea was formalin-fixed, paraffin-embedded, and examined microscopically. Deparaffinized 4-&mgr;m sections were stained with hematoxylin–eosin and Masson trichrome. Further tissue sections were subjected to immunohistochemical evaluation of CD34 and Ki-67 antigens. Results: Histologically, there was no scar tissue in the failed cornea. The biomicroscopic stromal opacity corresponded microscopically to an acellular area, devoid of keratocytes, and to compaction of the lamellar collagen. Amorphous, weakly eosinophilic interlamellar deposits, extending from the anterior to the posterior two thirds of the stroma, were noted. Conclusions: CXL is a promising procedure for the treatment of progressive keratoconus with minimal reported side effects. In the present case, we speculate that the short corneal soaking time (15 minutes according to the Siena protocol) may have resulted in inefficient ultraviolet-A blocking, thermal injury, and deeper keratocyte death. Inadequate keratocyte stem cells reservoir could also play a role in individual cases.

Optic nerve aplasia associated with macular ‘atypical coloboma’

Abstract. A 12‐year‐old patient presenting with absence of the optic disc and retinal blood vessels associated with atrophic macular lesion was studied. A toxoplasma IgG antibody test had been found positive at the age of 4 months. This test and the clinial findings suggested the possibility of optic nerve aplasia with atypical macular coloboma due to congenital toxoplasmosis. The pros and contras concerning this hypothesis are discussed by the authors.