Retinitis Pigmentosa: Current Clinical Management and Emerging Therapies

Abstract

Retinitis pigmentosa (RP) comprises a group of inherited retinal dystrophies characterized by the degeneration of rod photoreceptors, followed by the degeneration of cone photoreceptors. As a result of photoreceptor degeneration, affected individuals experience gradual loss of visual function, with primary symptoms of progressive nyctalopia, constricted visual fields and, ultimately, central vision loss. The onset, severity and clinical course of RP shows great variability and unpredictability, with most patients already experiencing some degree of visual disability in childhood. While RP is currently untreatable for the majority of patients, significant efforts have been made in the development of genetic therapies, which offer new hope for treatment for patients affected by inherited retinal dystrophies. In this exciting era of emerging gene therapies, it remains imperative to continue supporting patients with RP using all available options to manage their condition. Patients with RP experience a wide variety of physical, mental and social-emotional difficulties during their lifetime, of which some require timely intervention. This review aims to familiarize readers with clinical management options that are currently available for patients with RP.

Elevated Plasma Complement Factors inCRB1-associated Inherited Retinal Dystrophies

“…The latter may be also of interest for emerging CRB1 gene-augmentation therapy or mutational correction by allelic substitution via CRISPR/Cas9-mediated homology-directed repair or base editing, 62,63 because these therapeutic approaches are accompanied by immune activation when administered intravitreally or subretinally. 64 It would be important to determine to what extent the inflammatory markers identified in this study may help understand the side effects of gene therapy, such as increased chorioretinal atrophy that has recently been described after gene therapy using voretigene neparvovec for RPE65 -associated retinal dystrophies. 65,66 A major source of plasma complement components is the liver, but complement proteins are also produced and expressed in the retina, as well as by immune cells and various tissues.…”

Exploring anterion capsular contraction syndrome in cataract surgery: insights into pathogenesis, clinical course, influencing factors, and intervention approaches

“…RP was also reported to be one of the predisposing factors of late spontaneous IOL-capsular bag complex dislocation ( 49 , 51 ). On the other hand, recently, numerous studies have confirmed the role of inflammatory response and cytokines, such as platelet-derived growth factor AA (PDGF-AA), matrix metalloproteinase-2 (MMP-2), MMP3, MMP-7 and MMP-8, in the development of ACCS following cataract surgery in RP patients ( 52 , 53 ). That may reveal the pathogenesis of ACCS in RP patients.…”

“…That may reveal the pathogenesis of ACCS in RP patients. Additionally, the liquefaction of the vitreous may lead to postoperative insufficient support of the capsular bag, which could potentially become one of the reasons for IOL dislocation ( 53 ). Further works are required to determine the conclusive evidence of the pathogenesis to identify targeted and effective therapeutics, and specific prevention to limit the occurrence of surgical complication ( Figure 2 ).…”

Quest for good vision without peripheries - behavioral and fMRI evidence

“…Masuda and colleagues 18,19 exploring cortical responses to visual stimuli consisting of checkerboards and scrambled or intact faces, showed that when RP patients were asked to passively look at the stimuli, they exhibited either large unresponsive zones of V1 or responsive zones with reduced brain responses. Studies aimed at clinically assessing visual eld loss in RP used automated static perimetry test 20,21 together with a wide range of clinical tests, separately examining central and peripheral vision 22 . In the clinical context, ophthalmological tests of central and peripheral vision de ciencies are separated and acuity assessment is based exclusively on perception of stationary black stimuli on a white board, as in the Snellen letter chart.…”