Cultiu de capsul·les del cristal·li per a la investigacio i prevencio de la opacificacio de la capsula posterior
- Autores: Justin Christopher D'antin
- Directores de la Tesis: Ralph Michael (dir. tes.), Rafael Ignacio Barraquer Compte (codir. tes.)
- Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2020
- Idioma: español
- ISBN: 9788449095306
- Tribunal Calificador de la Tesis: Ricardo Casaroli Marano (presid.), María Elena Ibáñez de Sans (secret.), José Lamarca Mateu (voc.)
- Programa de doctorado: Programa de Doctorado en Biología Celular por la Universidad Autónoma de Barcelona
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
Cataracts are the world’s leading cause of blindness and are due to a progressive opacification of the eye lens. Fortunately, cataracts are easy to treat, however in many cases surgery can lead to a secondary loss of vision, known as posterior capsule opacification (PCO). PCO develops due to a combination of the proliferation, migration, and transdifferentiation of residual lens cells left in the lens capsule, after cataract surgery, resulting in a progressive loss of vision.
Many approaches for PCO prevention have been studied, from adjustments to surgical techniques and materials, to pharmacological treatment. Currently the most effective option is to mechanically prevent cells from invading the visual axis. Despite these advances, the development of PCO is still a common post-surgical complication that affects many patients.
In this thesis, we used an in vitro lens capsule tissue model to study the development and possible prevention of PCO. In our first study, we simulated the natural progression of PCO in vitro and subsequently tried to prevent it with different substances. However, despite using an aggressive approach of hydrogen peroxide, PCO still developed in half of the cases. This highlighted the impressive resilience of these cells and why prevention is such a difficult task.
In our second study, samples of PCO developed in vivo, were compared to our previous in vitro samples in order to better understand the development of PCO. We concluded that PCO is due to a failed attempt of the residual lens cells to regenerate the lens.
This made us reevaluate our approach to PCO prevention. Instead of studying ways to prevent the development of PCO pharmacologically, we intended to study whether residual lens epithelial cells could regenerate a transparent lens. The idea of regenerating the lens isn’t new, but it has only ever been observed and studied in animals and infants, never in human adults.
With this new goal in mind, we first wanted to study whether advanced cases of PCO naturally developed any transparent tissue, despite appearing opaque when observed clinically. In order to do this, we extracted advanced PCO tissue samples from ex vivo donor eye globes and thickly sectioned them in order to analyze them sagittally. We observed that in most cases a significant portion of the inner tissue is transparent. This further supported our idea of adult lens regeneration as a possible future treatment option.
Finally, we developed a new in vitro culture model that we believed would favor the development of normal lens cells instead of fibrotic cells. We made changes to the surgical preparation of the samples to increase residual lens cells, reduce the stress to these and improve the contact between the anterior and posterior capsules. However, lens regeneration was not achieved, but we did decrease some factors related to fibrotic PCO. This highlights the complexity of this new approach.
This thesis and the idea of lens regeneration as a treatment option, opens up many new interesting avenues of study and we intend to continue along this new path.
