Role of the Vitreous in Retinal Pathology: A Narrative Review.

The vitreous body is an anatomically and biochemically complex structure. Because of its proximity and firm adherence to the retina, researchers have examined the link between these two structures and how their individual pathologies might be connected. Several experimental and clinical studies have already demonstrated the important role of vitreous in the pathogenesis of retinal disorders. This narrative review highlights the role of the vitreous in retinal diseases and the improvements that have been made since the introduction of optical coherence tomography. This leads to a better understanding of vitreoretinal diseases and demonstrates its determinant role in other retinal pathologies, such as diabetic retinopathy or age-related macular degeneration. As we deepen our knowledge of the vitreous's structure, function, and abnormal conditions, we can better link the changes in diseases and identify effective treatments.

Erratum: [Corrigendum] Corneal endothelial changes induced by pars plana vitrectomy with silicone oil tamponade for retinal detachment.

[This corrects the article DOI: 10.3892/etm.2021.10393.].

Silicone oil complications in vitreoretinal surgery.

Objective: To illustrate the complications in subjects who experienced posterior vitrectomy and internal tamponade with silicone oil. Design: Prospective, observational, longitudinal, descriptive, series of cases. Material and methods: Patients who underwent posterior vitrectomy and internal tamponade with silicone oil of 1000 centistokes, from April to October 2021, were considered. All subjects included in the study had a complete ophthalmic examination pre and postoperatively on first day, first week and 1 to 6 months, and were assessed the best corrected visual acuity, ocular tension (raised > 21 mmHg, hypotony < 5 mmHg), emulsification, keratopathy, cataracts and posterior pole. Results: 40 eyes of 40 patients were considered; twenty women and 20 men, with an average age of 63 years (range 46 to 77 years). Conclusions: Complications are brief, treated medically or surgically, with better prognosis.

Corneal endothelial changes induced by pars plana vitrectomy with silicone oil tamponade for retinal detachment.

Silicone oils are effective intraocular tamponade agents in the treatment of severe retinal detachments, because they maintain the adhesion between neurosensory retina and retinal pigment epithelium, thanks to their ability to remove aqueous humor from the surface of the retina. To understand their effectiveness, it is important to know the characteristics of silicone oils. Patients should be closely monitored due to many complications associated with intraocular silicon oil, such as inflammatory reaction, raised intraocular pressure, refraction disorders, cataract, and emulsification. This study presents corneal endothelial changes and some intraocular complications caused by silicone oil used as an intraocular tamponade agent in the case of vitrectomy for complex retinal detachments. The aim of the study was to demonstrate the damage of corneal endothelial cells after the use of silicone oil in patients with retinal detachment surgery. Endothelial specular microscopy measurements were performed and the changes of the following parameters demonstrated the corneal damage: Mean cell density, coefficient of variation, average cell area, percentage of hexagonal cells, and corneal thickness. Three months postoperatively, a statistically significant decrease was observed in the following analyzed parameters: Mean cell density (P=0.04), and percentage of hexagonal cells (P=0.002); the remaining parameters also had a linear decrease (coefficient of variation, average cell area), but were statistically insignificant. Three months postoperatively, the corneal thickness presented a slight increase. Silicone oils are powerful tools when used wisely and within the limits of their use. These are often recommended in cases of severe detachment of the retina in patients at high risk of experiencing intraoperative complications.

Lipofuscin: a key compound in ophthalmic practice.

Lipofuscin is an intracellular aging pigment with fluorescent properties, found in retinal pigment epithelium cells of the eye. It is the main fluorophore used in fundus autofluorescence imaging techniques to diagnose, describe, and follow retinal disease. Lipofuscin forms by incomplete lysosomal degradation of cellular material previously subjected to oxidative changes. A2E is the most studied fluorescent component of lipofuscin, but most of its composition remains unknown. Lipofuscin is photoreactive, generating reactive oxygen species, which may explain its role in disease development. Further knowledge is needed concerning lipofuscin genesis, biochemical composition, fluorescent compounds, and role in pathogenesis of retinal degenerative disease.

Endothelial corneal cell damage after pars plana vitrectomy: analogy of different intraocular tamponade agents.

A reduction in the corneal endothelial cells multitude after anterior pole intervention is well established in numerous researches, but there are few articles that follow the impact of vitreoretinal interventions on the cornea, especially when endotamponade agents are used. The assessment of the endothelial corneal cells is needed since it facilitates the personal evaluation of the functional endothelial stock. Specular microscopy investigation offers a scale of the functional strength of the endothelium of cornea, which is vital before all intraocular interventions. Endotamponade agents are very suitable and important tools in the surgical treatment of retinal detachment, but their use must be differentiated depending on the uniqueness of each patient. This research shows corneal endothelial damages caused by intraocular tamponade agents of different types in the case of pars plana vitrectomy for cases of multitude retinal detachments. The purpose of the research was to determine the changes that appear in the endothelium of the cornea and to deal with the results when different tamponade agents are used in the surgical cure for retinal detachment. Specular endothelial corneal microscopy records were achieved and the modifications of the following parameters revealed corneal implication: mean endothelial cell densities, average cell area, coefficient of variation, hexagonality and corneal center thickness. On the first day and at three months postoperatively, a statistically significant reduction was observed for the CV, MCD, and HEX parameters (p 0.001), but no statistically significant difference of the two endotamponade agents (for MCD, p=0.15; for CV, p=0.63; for HEX, p=0.93) was noticed. AVG parameter had a statistically significant decrease (p 0.001) and there was also a statistically significant difference of the two endotamponade agents (p=0.03), patients with gas tamponade presenting a superior result. On the first day and at three months postoperatively, the corneal center thickness presented a statistically significant increase (p 0.001) and there was a statistically significant difference between the two endotamponade agents (p=0.03), patients with gas endotamponade presenting a superior result. In conclusion, using the intraocular tamponade agents helps reestablish the functional-anatomical recovery of the retina after surgery, but their special indication must be well-established for each case of retinal detachment.

Vital dyes in macular hole surgery.

Currently, surgical techniques, such as internal limiting membrane peeling, are used widely for macular holes, macular puckers, epiretinal membranes, diabetic macular edema, retinal detachment, retinal vein occlusions, vitreomacular traction, optic pit maculopathy, and Terson syndrome. This study aimed to highlight any differences regarding visual acuity and ocular tomography coherence changes after staining the internal limiting membrane with dilutions of Brilliant Blue G vs. lutein/zeaxanthin-based dyes. This study involved 30 eyes of 30 patients who had undergone posterior pole vitrectomy for idiopathic stage 4 macular hole. The study lot was divided in two subgroups, 15 eyes colored with Brilliant Blue and the other 15 eyes colored with lutein and zeaxanthin dyes. The association between visual prognosis, ocular tomography coherence changes and intraocular pressure was analyzed. The surgical treatment with required endoillumination levels and a 2-min period of dye using the Alcon Constellation Vision System had no negative impact on cell viability and improved visual acuity by 30%. Staining makes it easier to remove, to be quick and precise while performing macular surgeries. In has been observed that lutein and zeaxanthin dyes offer an intraoperative protective screen that protects photoreceptors more than Brilliant Blue while performing pars plana vitrectomy. Both study groups had good results in time. Surgical visualization is an evolving technology.

Injecting botulinum toxin into the treatment of blepharospasm.

The present paper is an introduction to this category of therapy, the injection of botulinum toxin into blepharospasm and, at the same time, an attempt to familiarize our readers with this concept. Our activity in this field started in 2014; the favorable results we have obtained since then have made us write this article. Abbreviations: BEB = Abnormal Benign Essential Blepharospasm, TXB = Botulinum Toxin.

Optic Pit Maculopathy.

This paper discusses a 32-year-old woman's case who presented a chronic decrease of visual acuity. In this case, the treatment was complex and consisted of a 25 GA vitrectomy, MLI peeling, covering the defect at the optic nerve papilla with that patch, gas endotamponade (C3F8). Abbreviations: MLI = internal limiting membrane; ODP-M = optic disc pit maculopathy.