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Purpose: Risk factors for metabolic syndrome include abdominal obesity, insulin resistance, hypertension, high triglycerides and/or low high-density lipoprotein cholesterol, and hyperglycemia. Risk factors for metabolic syndrome have been associated with dry eye disease; however, their association with meibomian gland disease (MGD), a subtype of dry eye, is unclear. In the present study, we investigated risk factors for metabolic syndrome in a dry eye cohort with and without MGD. Methods: This retrospective case-control study evaluated electronic medical records at a major urban outpatient medical center to identify patients with a known diagnosis of dry eye disease with and without MGD. Males and females were matched for age, smoking status, race, ethnicity, and body mass index (BMI). Patient demographics, anthropometric measurements, medical history, clinical findings, and serologies were analyzed. A diagnosis of MGD was based on clinical signs noted in the medical record. Results: MGD was not associated with BMI, smoking, type 2 diabetes mellitus, hypertension or hyperlipidemia in this dry eye cohort. MGD was associated with male sex and increasing age. While increasing age was weakly correlated with decreased low density lipoprotein cholesterol and non-high density lipoprotein cholesterol, serum lipid levels were not associated with MGD. Conclusion: Importantly, we found that risk factors for metabolic syndrome are not specifically associated with an increase in MGD when compared to non-MGD dry eye subjects. While risk factors for metabolic syndrome are associated with dry eye disease, they likely reflect a chronic systemic state of low-grade inflammation that negatively impacts the function of both lacrimal and meibomian glands.

Mitochondrial dysfunction is a major pathophysiological event leading to the onset of diabetic complications. This study investigated the temporal effects of hyperglycemia on mitochondrial metabolism in corneal epithelial cells. To accomplish this, human telomerase-immortalized corneal epithelial cells were cultured in a defined growth medium containing 6 mM glucose. To simulate hyperglycemia, cells were cultured in a medium containing 25 mM D-glucose, and control cells were cultured in mannitol. Using metabolic flux analysis, there was a hyperosmolar-mediated increase in mitochondrial respiration after 24 h. By day 5, there was a decrease in spare respiratory capacity in cells subject to high glucose that remained suppressed throughout the 14-day period. Although respiration remained high through day 9, glycolysis was decreased. Mitochondrial respiration was decreased by day 14. This was accompanied by the restoration of glycolysis to normoglycemic levels. These changes paralleled a decrease in mitochondrial polarization and cell cycle arrest. Together, these data show that chronic but not acute hyperglycemic stress leads to mitochondrial dysfunction. Moreover, the hyperglycemia-induced loss of spare respiratory capacity reduces the ability of corneal epithelial cells to respond to subsequent stress. Compromised mitochondrial function represents a previously unexplored mechanism that likely contributes to corneal complications in diabetes.

Percepção de autoinstilação de gotas oculares em idosos com ou sem dispositivo de apoio facialSelf instillation perception of eye drops in elderly patients with and without facial support device RESUMO Objetivo: Determinar o grau de dificuldade para instilação tópica ocular em idosos, com ou sem o auxílio de dispositivo de apoio facial, por meio de questionário. Observar qual método foi tecnicamente melhor para aplicação tópica ocular de gotas. Métodos: O estudo foi um ensaio clínico, controlado, randomizado e pareado, realizado em 50 pacientes idosos de setembro de 2015 a junho de 2016 na Policlínica Ronaldo Gazolla, Lapa-Rio de Janeiro. Um frasco de colírio Optive ® foi acoplado ao dispositivo de apoio facial denominado Eyedrop ® . Cada participante instilou o colírio com ou sem o auxílio do dispositivo em cada um dos olhos, sendo que a seleção ocular foi feita aleatoriamente. Foi perguntado ao paciente questões pré-formuladas sobre a dificuldade de ambos os métodos e a técnica de administração tópica ocular foi avaliada. Resultados: A instilação de gotas foi considerada difícil ou muito difícil por 10% dos idosos com o auxílio do dispositivo e por 36% sem o auxílio (p = 0,0047). Houve toque da ponta do colírio com os tecidos oculares em 64% dos pacientes que não usaram o Eyedrop ® e em 4% dos que o utilizaram (p=0,000001). A maior dificuldade descrita na instilação tradicional foi acertar o olho com a gota (32%) e com o dispositivo de apoio foi entender seu uso(4%). Conclusão: A maioria dos idosos instila colírios erroneamente, tocando a ponta do frasco em tecidos oculares, o que favorece sua contaminação. O dispositivo de apoio facial tornou mais segura e fácil a instilação.

Objective: The aim of this study was to evaluate the biocompatibility of Nanoskin for replacing volume in enucleated or eviscerated anophthalmic sockets of rabbits. Methods: An experimental study was carried out using enucleated or eviscerated rabbits, which received Nanoskin implants (Innovatecs®, São Carlos, Brazil), a cellulose produced by a bacteria (Acetobacter xylinum) using green tea as substrate. Implants of 10mm diameter/5mm of thickness were used placed in enucleated (G1) or eviscerated (G2) anophthalmic sockets of 21 rabbits. They were clinically examined daily, sacrificed at 7, 30 and 90 days after surgery and the material was removed and prepared for histological examination. Results: There were discrete signs of inflammation in the immediate postoperative period, with no evidence of infection or extrusion in any animal. However apparent reduction of volume during the trial period occurred. Histologically both groups were similar, with inflammatory cells (mainly monocytes and neutrophils), fibrin and hemaceas at 7 days postoperatively. The Nanoskin was presented as small pink spheres, with small gaps between them and permeated by few inflammatory cells. These cells have changed over the study, at 30 days multinucleated giant cells and mature fibroblasts that permeate the implant were observed. At 90 days, the structure of the implant was disorganized, amorphous, with necrotic debris and ovoid areas covered with thin pink membrane that seemed to cluster, empty or filled with no cellular pink or gray material. Conclusion: Nanoskin caused an inflammatory reaction leading to reabsorption and reduction of implant volume. New formulations should be studied in order to have a permanent product to repair the anophthalmic socket.

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Purpose Obstructive sleep apnea (OSA) is an established independent risk factor for peripheral neuropathy. Macro and microvascular changes have been documented in OSA, including high levels of potent vasoconstrictors. In diabetes, vasoconstriction has been identified as an underlying risk factor for corneal neuropathy. This study sought to establish a potential relationship between OSA and corneal nerve morphology and sensitivity, and to determine whether changes in corneal nerves may be reflective of OSA severity. Design Single center cross-sectional study. Methods Sixty-seven patients were stratified into two groups: those with OSA and healthy controls. Groups were matched for age, sex, race, smoking, and dry eye status. Outcome measures included serologies, a dilated fundus exam, dry eye testing, anthropometric parameters, corneal sensitivity, subbasal nerve plexus morphology, retinal nerve fiber layer (RNFL) thickness, and the use of questionnaires to assess symptoms of dry eye disease, risk of OSA, and continuous positive airway pressure (CPAP) compliance. Results No significant differences were observed in corneal nerve morphology, sensitivity, or the number of dendritic cells. In the OSA test group, RNFL thinning was noted in the superior and inferior regions of the optic disc and peripapillary region. A greater proportion of participants in the OSA group required a subsequent evaluation for glaucoma than in the control. In those with OSA, an increase in the apnea hypopnea index was associated with an increase in optic nerve cupping. Conclusions OSA does not exert a robust effect on corneal nerves. OSA is however, associated with thinning of the RNFL. Participants with glaucomatous optic nerve changes and risk factors for OSA should be examined as uncontrolled OSA may exacerbate glaucoma progression.