In the realm of Ophthalmology, research often propels innovation. Breakthrough findings sometimes draw inspiration for new treatment options, and diseases previously thought of as incurable gain favorable outcomes. Without research, innovation in the complex sphere of eye care could not exist. Leading Ophthalmologist Dr. Tom S. Chang MD, Founder of Acuity Eye Group, touts the importance of research on the evolution of the field. Recently, breakthrough research was found to show considerable insight into maintaining night vision during retinal degenerative disease. Chang touts these findings as being helpful in informing novel treatments for blindness-causing diseases.
A study in mice offers new insights into how the eyes adapt to changing conditions throughout a life cycle, and how they respond to degeneration. In the study, researchers studied a mouse model of retinitis pigmentosa, a group of diseases that causes the degeneration and loss of photoreceptor cells in the retina. This loss renders it difficult to see at night, an integral vision function necessary for the continuation of many daily activities. According to eye care innovators like Dr. Tom Chang MD, maintaining visual quality throughout the progression of a degenerative disease is an integral marker of being able to minimize the effects of the disease.
The research team conducted varying experiments on groups of healthy mice, and mice with retinitis pigmentosa. The mice with degenerative eye diseases were followed as the disease progressed. The ability to study the mice throughout varying stages of disease progression was a vital component of the study. It provided insight into how molecular changes evolve during the degeneration process. These experiments included whole-retinal RNA-sequencing, behavioral experiments, and electrophysiology experiments to garner comprehensive findings.
The direct results of the conducted experiments showed that the continued degeneration of photoreceptors sparked genomic changes. These changes compensated for the loss of vision ability due to degeneration of the rod photoreceptors. They were molecular in nature, affected the retina, and increased the frequency of signaling between photoreceptors and rod bipolar cells, which connect the inner and outer retina. As these molecular changes occurred, a continued ability to see well at night was documented. Though the mice affected by retinitis pigmentosa lost over half of all photoreceptors, they maintained an appropriate night vision.
The results of this study highlighted that the retina’s second-order neurons, which relay signals that project to the brain, maintain their activity as a response to photoreceptors regeneration. This responsive compensation allows the eyes to resist visual decline. This process is called homeostatic plasticity. As rod photoreceptors allow us to see at night, they are integral facets sometimes lost during the process of retinal degenerative disease.
While this type of plasticity has been previously seen as a response to deteriorating photoreceptor functionality, it was previously considered maladaptive instead of homeostatic. This discrepancy could have been witnessed as a result of previous studies being conducted at different stages of disease progression.
The Human Connection
The discovered compensatory molecular changes in this experiment may provide useful insight when translated to humans. This natural defense mechanism may serve to support reports that human patients with inherited retinal diseases can maintain normal standards of vision until the disease reaches a very advanced stage of progression. This connection can lead to the betterment of treatment options for various diseases that eventually lead to blindness. Understanding molecular overcompensation and changes can lead researchers to develop strategies to minimize and mitigate potential losses in vision. In turn, doing this successfully can allow affected patients to enjoy a more normalized lifestyle on a long-term basis.
The results of this breakthrough study suggest that retinal adaptation and molecular change is a leading contributor to elongated night vision for those affected by degenerative eye disease. This initial breakthrough lends a new perspective into ways to mitigate the long-term effects of degenerative eye disease. The evidence provides a strong building block for additional research to follow. With this connection made, additional research is needed to test these theories, implement new techniques to leverage this information in meaningful ways, and determine new courses of treatment.
In addition to innovating treatment to prolong night vision and other facets of vision, this discovery could also help eye care professionals in a proactive manner. Homeostatic plasticity could potentially be enhanced in the future to stave off degenerative disease progression, avoid loss of vision through proactive measures, and evolve the idea of a degenerative eye disease altogether. According to Dr. Tom Chang MD, the successful elimination of degenerative eye diseases could be one of the most prominent scientific breakthroughs of the century. Allowing individuals the confidence of never losing their vision due to degenerative eye disease, whether through enhanced homeostatic plasticity or not, would undoubtedly impact human life at its core. In the realm of Ophthalmology, such research is pivotal and provides confidence that degenerative eye disease symptoms could be effectively minimized in the near future.