ABSTRACT
The circadian rhythms originate within the organism and synchronize with cyclic fluctuations in the external environment. It has been demonstrated that part of the human genome is under control of the circadian clock and that a synchronizer that helps to maintain daily rhythms is Melatonin, a neuro-hormone primarily synthesized by the pineal gland during the night. The chronic disruption of circadian rhythm has been linked to many conditions such as obesity, metabolic syndrome, type 2 diabetes, cancer, and neurodegenerative diseases. Studies in the mice showed that the disruption of the retinal circadian rhythm increases the decline during the aging of photoreceptors, accelerating age-related disruption of cone cell structure, function, and viability and that the melatonin receptor deletion seems to influence the health of retinal cells, speeding up their aging. In conclusion, preserving the circadian rhythms could be to add to the prevention and treatment of age-related degenerative retinal diseases, and although additional studies are needed, melatonin could be a valid support to favor this "chronoprotection action".
Subject(s)
Diabetes Mellitus, Type 2 , Melatonin , Animals , Circadian Rhythm/physiology , Consensus , Diabetes Mellitus, Type 2/metabolism , Humans , Melatonin/metabolism , Melatonin/pharmacology , Mice , Retina/physiologyABSTRACT
PURPOSE: To investigate alterations of corneal layers in eyes treated for acute postoperative endophthalmitis. METHODS: In this retrospective, nonrandomized comparative study, eyes treated with 25 gauge pars plana vitrectomy (PPV) for acute post-cataract endophthalmitis (group A) were compared to eyes receiving uneventful cataract surgery (group B) and uneventful 25 gauge PPV for epiretinal membrane (group C). After a minimum follow-up of 8 months from last surgical procedure, laser scanning in vivo confocal microscopy (IVCM) was performed. RESULTS: Twelve eyes for each group were recruited. Comparing study eyes with control eyes of group B and C, no statistical difference was found in corneal epithelial cell density (p = n.s.), in density of nerve fibers (p = n.s.), mean grade of nerve reflectivity (p = n.s.), mean grade of nerve tortuosity (p = n.s.), mean grade of anterior keratocyte activation (p = n.s.), and corneal endothelium cell density (p = n.s.), whereas a statistically higher mean grade of posterior keratocyte activation was found in group A (p < 0.01). Epithelial and endothelial corneal morphologies were graded as regular in all groups. Langerhans cells and corneal dendritic-shaped hyper-reflective endothelial deposits were found in group A. Both findings were absent in group B and C, and the difference was statistically significant (p < 0.01). CONCLUSIONS: IVCM was a useful tool in the detection of microscopic chronic corneal abnormalities caused by postoperative endophthalmitis. These findings confirmed the presence of a subclinical chronic corneal inflammation localized to the posterior stroma that should be related to the infectious process. Future studies might clarify pathological processes in the acute phase of postoperative endophthalmitis.
Subject(s)
Cataract Extraction/adverse effects , Cornea/pathology , Endophthalmitis/diagnosis , Microscopy, Confocal/methods , Postoperative Complications/diagnosis , Adult , Aged , Aged, 80 and over , Endophthalmitis/surgery , Female , Follow-Up Studies , Humans , Male , Middle Aged , Postoperative Complications/surgery , Reoperation , Retrospective Studies , Vitrectomy/methodsSubject(s)
Cyclosporine , Dry Eye Syndromes , Administration, Topical , Cornea , Humans , Immunosuppressive Agents , Microscopy, Confocal , Ophthalmic SolutionsABSTRACT
PurposeTo investigate the effect of cyclosporine on corneal ultrastructure and on major signs and symptoms of patients with dry eye disease.Patients and methodsIn this prospective cohort study, patients with dry eye disease were treated with a drop of cyclosporine 0.05% twice daily. Clinical evaluation was carried out at baseline and at months 1, 3, and 6. All patients completed the Ocular Surface Disease Index (OSDI) questionnaire, and tear film break-up time (BUT), fluorescein and lissamine green staining, and Schirmer test were carried out. In vivo confocal microscopy was also performed and epithelial cellular density, keratocyte activation, and subbasal plexus morphology were assessed.ResultsA total of 40 patients completed the study. After 6 months, OSDI, BUT, and fluorescein and lissamine green staining showed a clinically significant improvement. During the 6-month follow-up, density of intermediate epithelial cells increased from 1969.5±85.4 cell/mm2 to 4881.2±175.7 cell/mm2 (P<0.01); average grade of keratocyte activation decreased from 3.6±0.1 to 1.8±0.1 (P<0.001); average grade of number of subbasal nerves decreased from 5.3±0.2 to 2.6±0.2 (P<0.001); average grade of nerve reflectivity decreased from 3.8±0.1 to 2.1±0.2 (P<0.001); and average grade of nerve tortuosity decreased from 3.8± 0.1 to 2.2±0.2 (P<0.001).ConclusionCyclosporine was effective in controlling symptoms and signs of dry eye disease. In vivo confocal microscopy showed an increase in cell density of intermediate epithelium cells, a decrease in hyperreflective keratocytes, and a decrease in density, tortuosity, and reflectivity of nerve fibers.
