Wound healing following refractive surgery in hens

Producción CientíficaThe wound-healing response is critical to the outcome of refractive surgery and studying wound healing contributes to an understanding of the pathophysiology of other corneal injuries. Animal models allow research to be conducted with sufficient samples and under controlled parameters. We studied the hen to determine the healing process from clinical, biophysical, and biological standpoints after photorefractive keratectomy (PRK). PRK ( 6.0 diopters) was performed in hen eyes. At 3, 6, 12, 24, 48, and 72 h and 5, 7, 15, 30, and 60 days postoperatively, we studied the clinical follow-up, objective measurements of light transmission (direct transmittance), apoptosis by TUNEL assay, proliferation by immunocytochemical analysis of 5-bromo-20-deoxyuridine, and expression of alpha smooth muscle actin (SMA) in myofibroblasts in the corneas. Hen corneas reepithelialize quickly. Haze developed from 5 to 60 days after surgery and was correlated with the appearance and finalization of the expression of SMA. The direct transmittance of light was low during the first 15 days and improved at 30 and 60 days. TUNEL-positive cells were observed 3 h after surgery and the numbers decreased thereafter. Epithelial proliferation began at 12 h and was greater at 48 h, while stromal cell proliferation began at 24 h and was greater at 72 h. The hen cornea is anatomically similar to the human cornea, and the manner in which it heals is a good model for studying different surgical techniques and pharmacologic assays

Ocular chemical burns in the workplace: epidemiological characteristics of a Spanish cohort.

Background Epidemiological studies focusing on occupational pathologies can be an important medium through which to bring about change with respect to workplace accidents, both in terms of prevention planning and management as well as the appropriate care following an accident. Ocular chemical burns benefit from urgent attention as, if not treated early and appropriately, the tissue of the eye and its functionality can be seriously compromised. The objective of this study was to collate epidemiological data on workplace ocular chemical burns which could in turn serve to identify key action points in terms of occupational health. Methods Cohort study with 604 cases of chemical burns to the eye occurring in the workplace between 2014 and 2015. Criteria inclusion were diagnosis of chemical burn, patient seen at the medical centre of the mutual society, workplace acquired ophthalmic pathology leading to the issuing of a sickness certificate. No exclusion criteria were defined. Results Ocular chemical burns were the second most common workplace eye injury (12.68%) behind foreign bodies in the eye (43.42%). Men accounted for 68.54% of cases of ocular chemical burns. In around 75% of cases, sickness certification was for less than 7 days, although 6 patients suffered permanent disability. The occupational sector which was most affected particularly the industry service industry. The economic costs with these workplace injuries were extracted. Conclusions Appropriate early medical assistance is essential. The production and distribution of clinical guides for health care workers could optimise first line assistance and mitigate possible training deficiencies.pre-print169 K

Novel Diagnostic and Therapeutic Methods in Ocular Surface and Corneal Diseases

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Estudio de la capa de Bowman en diferentes modelos animales y su papel en la protección a radiaciones solares

En este artículo presentamos la respuesta del sistema ocular de distintas especies animales al estrés óptico generado por radiación ultravioleta de intensidad extrema. Centramos nuestra atención en la manera como queda afectada la capa de Bowman en la córnea de cada especie.In this paper we study the reaction of the vision system of different animal species to the optical stress produced by extreme UV radiation. We focus the attention in the Bowman´s layer of the cornea

Queratoconjuntivitis epidémicas en el trabajo. Reflexiones en torno a su manejo y catalogación.

Introducción: las conjuntivitis epidémicas presentan alto riesgo de contagio. Pueden tener etiología laboral. Objetivos: conocer datos epidemiológicos y cuantificar costes económicos; aportar información sobre manejo y catalogación. Material / Métodos: estudio descriptivo-retrospectivo de una serie de casos (contingencias profesionales) por conjuntivitis epidémica (CIE-9) durante 2014-2015 en FREMAP, que generaron procesos de incapacidad temporal. Resultados: sobre el total de patologías oftalmológicas laborales con baja, representaron el 1,6%. Mujeres 75%, sector servicios y 39 años de media. Bilateral 73% de los casos. El 46% recibió asistencia previa. Tratamiento médico 86,48% (colirios / otros fármacos). Días de baja 1068 (media/ proceso 28,48 días). Costes sanitarios 17511,59 euros y prestaciones 40060,11 euros. Conclusiones: sector Servicios, mujeres y profesionales sanitarios mayor prevalencia. Mayoritariamente, afectación ambos ojos. Prevenir, el mejor tratamiento. No correlación estacional. Esencial diagnóstico precoz, interrumpir actividad laboral del trabajador y extremar medidas para evitar contagio. Tasas de absentismo y costes económicos relevantes.post-print400 K

Tributo al professor Miguel F. Refojo, PhD, DSc (1928---2016)

López-Alemany, A.; Compañ Moreno, V.; Merayo Lloves, J.; Gonzalez-Meijome, J. (2017). Tribute to Professor Miguel F. Refojo, PhD, DSc (1928-2016). Journal of Optometry. 10:1-2. https://doi.org/10.1016/j.optom.2016.12.001S121

Development and Optimization of Freeze-Dried Eye Drops Derived from Plasma Rich in Growth Factors Technology

Purpose: To investigate whether plasma rich in growth factors (PRGF) eye drops maintain their biological potential after a freeze drying process. The addition of a lyopro-tectant like trehalose was also evaluated. Methods: Blood from three healthy donors was collected to obtain eye drops by PRGF technology. The resultant eye drops were divided in four groups: PRGF, freeze-dried PRGF (PRGF lyo), and PRGF lyophilized mixed with 2,5% trehalose (PRGF lyo+2.5T) or 5% trehalose (PRGF lyof+5T). Chemical and biological characteristics were evaluated. Photorefractive keratectomy was performed on C57BL/6 mice which were divided in three treatment groups: control, PRGF, and PRGF lyo. Corneal wound healing and haze formationwere evaluated macroscopically. Eyeswere collected at 1, 2, 3, and 7 days after surgery, and were processed for histologic studies. Results: The pH values of PRGF samples increased significantly after the lyophilization process. Osmolarity levels increased significantly in PRGF samplesmixed with trehalose in comparison with PRGF samples without protectants. The freeze drying process maintained growth factors levels as well as the biological properties of PRGF eye drops even without the use of lyoprotectants. PRGF lyo treatment significantly decreased the re-epithelialization time and haze formation in photorefractive keratectomy-treated corneas regarding PRGF and control groups. Furthermore, the PRGF lyo group significantly decreased the number of smooth muscle actin-positive cells in comparison with the control group at each time of the study and at days 2 and 3 in the PRGF group. Conclusions: The freeze drying process preserves the protein and growth factor content as well as the biological properties of PRGF eye drops, even without the use of protectants. Freeze-dried PRGF eye drops accelerate corneal tissue regeneration after photorefractive keratectomy in comparison with the control group. Translational Relevance: Our study shows the feasibility to preserve the biological capability of PRGF eye drops as freeze-dried formulation, avoiding the addition of protectants.This study received funding from the Basque Country Government, within the Elkartek program, phase I. Support program for collaborative research in strategic area, within the project named SINET (reference KK-2018/00048

Measurement of correlation between transmission and scattering during wound healing in hen corneas

Producción CientíficaThe aim of this work is to provide experimental data for corneal transparency and scattering to help create a more complete model of corneal transparency. The scattered light in 96 healing hen corneas was measured for three wavelengths by a scatterometer constructed in the Optics Laboratory (The University of Valladolid, Spain). With the help of mirrors and beamsplitters, the light from the three lasers is directed toward the cell containing the sample to be measured. The measured scattered light varies between six orders of magnitude. Corneal transmissivity, mean cosine of a scattering angle, and angular distribution of scattered light were all computed. The total transmitted light remained practically constant over a wide range of light values transmitted in a forward direction (direct transmissivity). The value of the mean cosine of the scattering direction is very close to the unit (g40:98), even in corneas with high opacities. The behavior of g indicates that even damaged corneas evidence extremely small scattering, compared to other biological tissues. The transmission reduction of each cornea is related to an increase in scattered light. In all cases, scattered light is concentrated at very small angles. This behavior is acceptable in corneas that are healthy or which evidence small lesions, but remains in corneas that are severely injured

Clinical, Refractive and Histological Reversibility of Corneal Additive Surgery in Deep Stroma in an Animal Model.

Producción CientíficaThe aim was to evaluate the reversibility of the clinical and histological changes induced in the corneas of an animal model after removing an intracorneal ring segment (ICRS).Surgery for this study was performed in 38 eyes of an experimental animal model (Gallus domesticus) for ICRS surgery (Ferrara technique). The animals without complications were randomized to two groups; in all of them, 1 segment was implanted in each eye and later removed at different times (1 and 3 months after implantation). In each group, after explantation, corneas were processed at different times for histological analysis with hematoxylin and eosin (H&E) stain and electronic microscopy. The refractive state of the eyes was also measured.In corneas without complications (88.23%), explantation was performed correctly. During the first few days, around the area where the ICRS was implanted we observed deposits of cells and a moderate degree of corneal opacity (haze). These signs decreased progressively without disappearing completely. Histologically, at 7 days, we observed hyperplasia and abnormal arrangement of collagen fibers. Later, these findings also decreased in both groups, albeit at a faster rate in group 1. Minimal changes were observed in electron microscopy up to the end of the study in both groups. Preoperative refractive state was achieved at 1 month after explantation in both groups.ICRS can safely be explanted from the cornea. Refractive reversibility was achieved at 1 month after explantation. However, the clinical and histological findings after ICRS explantation depend on the time from implantation to explantation

Galenic validation of plasma rich in growth factors eye drops

Objective: Galenic evaluation of the process for obtaining and storing the platelet rich in growth factors PRGF-Endoret® eye drops. Method: To assess whether the PRGF-Endoret® eye drops process is aseptically obtained, a sterility test was carried out on the eye drops; the tightness of the PRGF-Endoret® eye drops containers was also analyzed. Likewise, the chemical and biological properties of the PRGF- Endoret® eye drops were evaluated after the obtaining process and storage. Eye drop filtration tests, one cycle of freezing at –20 °C and thawing, and eye drop stability for three and six months stored at –20 °C were included. Results: The results obtained in the sterility test showed no microbial contamination in any of the analyzed eyedropper; tightness test showed that 100% of the eyedrop containers and the 98.4% of the plugs analyzed remained hermetic. On the other hand, all the growth factors measured remained constant after filtering the PRGF-Endoret® eye drops. Furthermore, the different eye drop stability tests carried out in this study showed no significant changes in the growth factors levels, cell proliferative activity or in the chemical characteristics analyzed. Conclusions: The PRGF-Endoret® eye drops are obtained in a safety and aseptic manner following the guidelines issued by the Spanish Agency for Drugs and Health Products and the Ministry of Health to obtain medicines for human use. The PRGF-Endoret® eye drops maintain their physical-chemical and biological properties after being subjected to different storage times and temperatures