Influence of gut microbiota on eye diseases: an overview

The microbiota is a dynamic ecosystem that plays a major role in the host health. Numerous studies have reported that alterations in the intestinal microbiota (dysbiosis) may contribute to the pathogenesis of various common diseases such as diabetes, neuropsychiatric diseases, and cancer. However, emerging findings also suggest the existence of a gut-eye axis, wherein gut dysbiosis may be a crucial factor influencing the onset and progression of multiple ocular diseases, including uveitis, dry eye, macular degeneration, and glaucoma. Currently, supplementation with pre- and probiotics appears is the most feasible and cost-effective approach to restore the gut microbiota to a eubiotic state and prevent eye pathologies. In this review, we discuss the current knowledge on how gut microbiota may be linked to the pathogenesis of common eye diseases, providing therapeutic perspectives for future translational investigations within this promising research field

Multimodal Imaging of Lamellar Macular Holes

Evolution of imaging techniques has renewed interest in the diagnosis of lamellar macular hole (LMH) and greatly implemented the possibilities of gaining more detailed insights into its pathogenesis. Among noninvasive techniques, optical coherence tomography (OCT) is considered the primary examination modality to study LMHs, given its ability to image foveal structure and its widespread availability. OCT also allows to resolve the epiretinal materials associated with LMH, i.e., tractional epiretinal membranes (ERMs) and epiretinal proliferation (EP). En face OCT reconstructions are useful to confirm the foveal abnormalities shown by the eyes with LMH, whereas OCT angiography may reveal alterations of the size and shape of the foveal avascular zone and alterations of the density of the superficial and deep vascular plexuses. On slit-lamp biomicroscopy or fundus camera examination, LMH appears as a round or oval, reddish lesion at the center of the macula, slightly darker than the surrounding retina. The associated tractional ERM, causing wrinkling and glistening of the retinal surface, is usually readily appreciable, whereas EP is hardly apparent on biomicroscopy or fundus photography since the retina surface appears smooth. When imaged with blue fundus autofluorescence (B-FAF) imaging, LMHs are characterized by an increased autofluorescent signal, the intensity of which does not correlate with the thickness of the residual outer retinal tissue. Green reflectance and blue reflectance (BR) images clearly show the increased reflection and wrinkling of the retinal surface caused by tractional ERM associated with LMH. BR and multicolor imaging enable the visualization of EP associated with LMH in the form of a sharply demarcated dark area and in the form of a yellowish area surrounding the hole, respectively. Scarce data regarding invasive imaging techniques, such as fluorescein angiography, for the study of LMH are available in the literature. The aim of this review is to evaluate the contribution that each imaging modality can provide to study the morphologic characteristics of LMH

Corneal Epithelial Wound Healing Promoted by Verbascoside-Based Liposomal Eyedrops

Different liposomal formulations were prepared to identify those capable of forming eyedrops for corneal diseases. Liposomes with neutral or slightly positive surface charge interact very well with the cornea. Then these formulations were loaded with verbascoside to heal a burn of corneal epithelium induced by alkali. The cornea surface affected involved in wound was monitored as a function of time. Experimental results were modeled by balance equation between the rate of healing, due to the flow of phenylpropanoid, and growth of the wound. The results indicate a latency time of only three hours and furthermore the corneal epithelium heals in 48 hours. Thus, the topical administration of verbascoside appears to reduce the action time of cells, as verified by histochemical and immunofluorescence assays

Intestinal microbiome: a new target for chalaziosis treatment in children?

Intestinal dysbiosis (changes in the gut commensal microbiome) is related to several ophthalmic diseases. The aim of this study was to verify whether oral specific probiotics can alter the clinical course of chalaziosis and its recurrence. A prospective comparative pilot study involving 26 children suffering from chalaziosis was conducted. Children were randomly divided into two groups. The first group received medical treatment (lid hygiene, warm compression and dexamethasone/tobramycin ointment for at least 20 days), and the second group received medical treatment plus a daily supplementation of oral probiotics (≥ 1 × 10^9 live cells of Streptococcus thermophilus ST10 (DSM 25246), ≥ 1 × 10^9 live cells of Lactococcus lactis LCC02 (DSM 29536) and ≥ 1 × 10^9 live cells of Lactobacillus delbrueckii subsp. bulgaricus (DSM 16606) with maltodextrin as the bulking agent (Probiotical S.p.A., Novara, Italy). All patients were evaluated at 2-week intervals for 3 months. If the lesion had not disappeared or decreased in size to 1 mm or less in diameter at the time of subsequent visits, the same procedure was repeated for another 3-month cycle. There was a significant difference in the time taken for complete resolution of the chalazion between the two groups in favour of the children receiving the probiotics. The treatment was not associated with any significant complications in either group. Trial registration: The trial was registered at clinical trials.gov under NCT04322500 on 25/03/2020 (“retrospectively registered”). Conclusions: Modification of the intestinal microbiome with specific probiotics can alter the clinical course of chalaziosis in children by re-establishing intestinal and immune homeostasis. Probiotic supplementation can increase the effectiveness of traditional therapies by prompting the complete resolution of chalaziosis in a shorter amount of time, in an easy and feasible way.What is Known:• The intestinal microbiome plays a crucial role in several inflammatory diseases of the eye and is considered a therapeutic target.• Probiotics play a role in the prevention and treatment of different conditions in children.What is New:• In children probiotic supplementation is safe and effective.• Probiotic supplementation reduced the time required for complete resolution of the chalazion

Exploring Epigenetic Modifications as Potential Biomarkers and Therapeutic Targets in Glaucoma

Glaucoma, a complex and multifactorial neurodegenerative disorder, is a leading cause of irreversible blindness worldwide. Despite significant advancements in our understanding of its pathogenesis and management, early diagnosis and effective treatment of glaucoma remain major clinical challenges. Epigenetic modifications, encompassing deoxyribonucleic acid (DNA) methylation, histone modifications, and non-coding RNAs, have emerged as critical regulators of gene expression and cellular processes. The aim of this comprehensive review focuses on the emerging field of epigenetics and its role in understanding the complex genetic and molecular mechanisms underlying glaucoma. The review will provide an overview of the pathophysiology of glaucoma, emphasizing the intricacies of intraocular pressure regulation, retinal ganglion cell dysfunction, and optic nerve damage. It explores how epigenetic modifications, such as DNA methylation and histone modifications, can influence gene expression, and how these mechanisms are implicated in glaucomatous neurodegeneration and contribute to glaucoma pathogenesis. The manuscript discusses evidence from both animal models and human studies, providing insights into the epigenetic alterations associated with glaucoma onset and progression. Additionally, it discusses the potential of using epigenetic modifications as diagnostic biomarkers and therapeutic targets for more personalized and targeted glaucoma treatment

Corneal Epithelial Wound Healing Promoted by Verbascoside-Based Liposomal Eyedrops

Different liposomal formulations were prepared to identify those capable of forming eyedrops for corneal diseases. Liposomes with neutral or slightly positive surface charge interact very well with the cornea. Then these formulations were loaded with verbascoside to heal a burn of corneal epithelium induced by alkali. The cornea surface affected involved in wound was monitored as a function of time. Experimental results were modeled by balance equation between the rate of healing, due to the flow of phenylpropanoid, and growth of the wound. The results indicate a latency time of only three hours and furthermore the corneal epithelium heals in 48 hours. Thus, the topical administration of verbascoside appears to reduce the action time of cells, as verified by histochemical and immunofluorescence assays

Ocular Tolerability of Bimatoprost 0.1 mg/mL Preservative-Free versus Bimatoprost 0.1 mg/mL with Benzalkonium Chloride or Bimatoprost 0.3 mg/mL Preservative-Free in Patients with Primary Open-Angle Glaucoma

Abstract: This study aimed to evaluate whether the therapeutic switch from a formulation of Bimato- prost 0.1 mg/mL with benzalkonium chloride (BAK) or Bimatoprost 0.3 mg/mL preservative-free to a formulation of Bimatoprost 0.1 mg/mL preservative-free could improve eye surface conditions in patients with glaucoma; intraocular pressure (IOP) was also evaluated. All patients meeting the inclusion criteria were eligible for the therapeutic switch to Bimatoprost 0.1 mg/mL preservative- free. At each check visit, enrolled patients underwent a break-up time (BUT) test, an ocular surface disease index (OSDI) test, and a three-point tonometric curve. A total of 40 patients were enrolled (23 were in therapy with Bimatoprost 0.1 mg/mL with BAK and 17 with Bimatoprost 0.3 mg/mL preservative-free). Significant differences of OSDI and BUT between Bimatoprost 0.1 mg/mL with BAK at baseline vs. Bimatoprost 0.1 mg/mL preservative-free at 14 and 28 days (p < 0.0001 and p = 0.0003, respectively) were recorded. Similarly, significant differences of OSDI and BUT between Bimatoprost 0.3 mg/mL preservative-free at baseline vs. Bimatoprost 0.1 mg/mL preservative-free at 14 and 28 days (p < 0.0001 for both) were found. Bimatoprost 0.1 mg/mL preservative-free has a better tolerability profile associated with non-therapeutical inferiority in the control of IOP compared to the other Bimatoprost formulations

Effectiveness of oral probiotics supplementation in the treatment of adult small chalazion

● AIM: To define the possible beneficial impact of probiotics oral supplementation on patients affected by chalazion. ● METHODS: Prospective comparative pilot study on 20 adults suffering from chalazion randomly divided into two groups. The first group (n=10) received conservative treatment with lid hygiene, warm compression, and dexamethasone/tobramycin ointment for at least 20d. The second group (n=10), in addition to the conservative treatment, received a mixture of probiotic microorganisms of Streptococcus thermophilus ST10 (DSM 25246), Lactococcus lactis LLC02 (DSM 29536) and Lactobacillus delbrueckii (DSM 16606) once a day up to 3mo. Chalazia were classified according to their size into three groups: small (<2 mm), medium (≥2 to <4 mm), or large (≥4 mm). When conservative treatment with and without probiotics supplementation failed to resolve the lesion, invasive methods were used, intralesional steroid injection in medium size chalazion and surgical incision and curettage for the largest ones. ● RESULTS: Medical treatment with or without probiotics supplementation was effective only on the small size chalazia. There was a significant difference in the time taken for complete resolution of small size chalazia between the two groups in favor of the patients receiving probiotics (38.50±9.04d vs 21.00±7.00d, P=0.039). Medium and large size chalazia did not respond to medical treatment with or without probiotics supplementation over the follow-up period (3mo). The treatment did not induce any complications in both groups and no recurrence of chalaziosis was recorded in both groups. ● CONCLUSION: The considerable difference in time taken for complete resolution of small chalazia between the two groups in favor of the experimental one confirms the presence of a gut-eye axis