Critical Barriers to Progress of Retinitis Pigmentosa Essay -- Health

CRITICAL BARRIERS TO PROGRESS The lack of homogeneity and progressive nature of RP poses a crucial problem to the development of novel therapies (Marmor 1979, Greenwald 2009).RP is typically late in its onset and progresses slowly; as such an accurate determination of age of onset is problematic (Tsujikawa 2008). This is particularly troublesome as no efficient therapies are currently available with genetic counseling being key in the treatment of the disease, and without an accurate age of onset, counseling can be troublesome at best (Tsujikawa 2008). Diversity exists not only in disease onset and progression rate, but underlying genetics as well (Chow 2004); over 180 gene mutations are associated with photoreceptor diseases without cures or effective therapies (Greenwald 2009). This makes the development of molecular based therapies difficult as one therapy may only aid one specific type of RP, with a variance in efficacy mirroring the variance in phenotype severity. Even within a single family, a specific muta tion may result in a variety of phenotypes (Sohocki 2000). Also, within a single gene, multiple mutations may occur, each with its own retinal degeneration phenotype (Gamundi 2005). Even if these issues with known genetic causes could be mitigated, cases of adRP exist where all known RP associated genes have been excluded, suggesting additional genetic heterogeneity (Alvarez 2007). Within Caucasian populations, 50-60% of cases of RP are diagnosed as â€Å"sporadic† due to the inability to pinpoint inheritance patterns (Ziviello 2005). In one study of Italian families with adRP, only 27% of cases could be linked to a known gene, with 73% of cases having alterations in unknown genes (Ziviello 2005). Because of the challenges mo... ...ir mobility and independence indirectly, resulting in an overall greater increase in quality of life. Additionally, this study will improve our knowledge of retinal degenerations and the ability of degenerated photoreceptors with mostly preserved retinal circuitry to be stimulated more effectively through differential brightness/contrast/exposures to increase visual perception. Success of the aims of this study will alter treatments and services in the field as optometrists will have access to a potential prosthesis and resource to give their patients to improve their quality of life once diagnosed with RP. Additionally, this device will give a non-invasive alternative to those patients with early stage disease progression, those RP patients with unknown underlying genetic determinants, and those end-stage patients that do not wish to have subretinal implantation.