Insulina colirio en afecciones de la superficie ocular / Insulin Eye Drops for Eye Surface Conditions

Cuando se produce una erosión corneal y fracasa la epitelización corneal surgen los defectos epiteliales corneales persistentes, cuyo tratamiento es un desafío para el oftalmólogo. Es muy frecuente el fracaso del tratamiento convencional por lo que se mantiene el interés en la búsqueda de otros factores de crecimiento para la cicatrización epitelial tales como los colirios de insulina. La insulina es un péptido estrechamente relacionado con el factor de crecimiento similar a la insulina 1. Su mecanismo de acción no es bien comprendido, sin embargo se acepta que es capaz de inducir migración y proliferación de las células epiteliales corneales, por lo que promueve y acelera la reepitelización de defectos epiteliales persistentes refractarios a tratamiento. La ausencia de una presentación comercial de colirio de insulina, hace necesario conocer su estabilidad físicoquímica y microbiológica así como la eficacia, efectividad y seguridad del colirio de insulina a diferentes concentraciones. De ahí la motivación para realizar una revisión de la literatura existente sobre el empleo del colirio de insulina en el tratamiento del defecto epitelial corneal persistente. Se realizó la búsqueda en bases de datos electrónicas como PubMed Central, EBSCO, Clinical Trials.gov, MEDLINE OVID, EMBASE OVID con el objeto de identificar artículos relacionados con el tema(AU)

When corneal erosion occurs and corneal epithelialization fails, persistent corneal epithelial defects arise, whose treatment is a challenge for the ophthalmologist. The failure of conventional treatment is very frequent; therefore, there is still interest in the search for other growth factors for epithelial healing, such as insulin eye drops. Insulin is a peptide closely related to insulin-like growth factor 1. Its mechanism of action is not well understood; however, it is accepted that it is capable of inducing migration and proliferation of corneal epithelial cells, thereby promoting and accelerating reepithelialization of persistent epithelial defects refractory to treatment. The absence of a commercial presentation for insulin eye drops makes it necessary to know its physicochemical and microbiological stability, as well as the efficacy, effectiveness and safety of insulin eye drops at different concentrations; hence the motivation to review the existing literature on the use of insulin eye drops in the treatment of persistent corneal epithelial defects. The search was carried out in electronic databases such as PubMed Central, EBSCO, Clinical Trials.gov, MEDLINE OVID, EMBASE OVID, with the aim of identifying relevant articles related to the topic(AU)

Histopathological and Immunohistochemical Study of the Toxicity of UVB-Irradiation on Rabbit's Cornea: Possible Antioxidant Role of Trehalose.

Aims: This Study aimed to evaluate toxic changes that might occur in rabbit cornea after UVB exposure and possible protective role of Trehalose. Study Design: Eighteen adult white female rabbits were divided into three groups, six rabbits for each one. Group Ι received buffered saline (negative control), Group ΙΙ irradiated by UVB (positive control) and Group ΙΙI irradiated by UVB with concomitant application of Trehalose eye drops. Place and Duration of Study: Department of Pharmacology, and Department of Histopathology, Umm AL Qura University (UQU), KSA, between April 2012 and May 2012. Methodology: Eighteen rabbits were divided into three equal groups. Group Ι received buffered saline (0.9%), Group ΙΙ Only the cornea was irradiated by UVB, and Group ΙΙI were treated (by dropping trehalose three drops in each eye, six times daily) after irradiated with UVB. Two weeks after treatment, the excised corneas were employed for histopathological and immunohistochemical examinations. Results: UVB exposure induced cell death and thinning of the corneal epithelium, while the irradiated epithelium was preserved well morphologically with concomitant application of Trehalose eye drops. The irradiated corneal epithelium was significantly (P =0.026) thicker than eyes treated with Ultraviolet and Trehalose eye drops. Apoptotic cells were significantly (P =0.001) reduced in negative control and Trehalose -treated eyes than positive control eyes. Trehalose was showed to prevent oxidative stress, accelerated corneal healing, restored corneal transparency and prevent corneal neovascularization in irradiated corneas. Caspase-3, was strong significantly expressed (P<0.5) in the corneal epithelium two weeks after irradiation and corneal neovascularization was evident. Conclusion: Trehalose prevents apoptosis after the UVB irradiated cornea, so topical Trehalose administration may be a candidate treatment to prevent the damages by UVB irradiation with wide applications in clinical toxicology.

Influence of topical anesthetics on oculocardiac reflex and corneal healing in rabbits / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the incidence of oculocardiac reflex (OCR) with two anesthetic regimens and its prevention using topical anesthetics in a rabbit model. We also investigated the effect of topical anesthetics on corneal healing.METHODS: Forty-eight clinically healthy adult New Zealand white rabbits of either sex were divided into two groups (Group A and B) and anesthetized with either ketamine (Group A, n=24) or propofol (Group B, n=24). In this study , the incidence of OCR was recorded in each group with a variety of ocular manipulation with or without the use of topical anesthetics (40g/L lignocaine, 5g/L proparacain, 5g/L bupivacaine). Corneal toxicity and healing following the use of each topical anesthetic was assessed one day after surgery and up to 7 days postoperatively by clinical examination of the eye, histopathology and collagen staining and transmission electron microscopy.RESULTS: No incidence of OCR was recorded with ocular manipulation under ketamine anesthesia, whereas significant reduction in heart rate (P<0.01) was recorded under propofol anesthesia. Topical anesthetics could successfully prevent the OCR without affecting the corneal healing.CONCLUSION: Topical anesthetics may be recommended for prevention of OCR without any local adverse effect.

The Effect of Disposable Bandage Contact Lenses on Time and Velocity of Corneal Epithelial Healing after Myopic Epikeratoplasty

To investigate the effect of disposable contact lenses (CL) on the corneal epithelial healing, a prospective study of 30 myopic epikeratoplasties which were divided into 3 groups according to the method for promoting the corneal epithelial healing was conducted. The groups are consisted of 10 eyes with pressure patch, 10 eyes with Acuvue(R) disposable CL and 10 eyes with SeeQuence(R) disposable CL. Corneal epithelial healing was completed in the pressure patch, Acuvue(R) CL and SeeQuence(R) CL group at 3.4, 3.5 and 3.4 postoperative days, respectively. Corneal epithelial healing rate during postoperative 1, 2 and 3 days are 0.33, O.78, and O.44mm2/hour in pressure patch group, O.24, O.92 and O.37mm2/hour in Acuvue(R) CL group, and O.30, O.79 and O.38mm2/hour in SeeQuence(R) CL group respectively. From the above results, it is concluded that there was no statistically significant difference of the corneal epithelial healing time and rate between the pressure patching and disposable bandage CL wearing after myopic epikeratoplasty.