Is retinitis pigmentosa a progressive disease?

Is Retinitis Pigmentosa Progressive?

Yes, retinitis pigmentosa (RP) is definitively a progressive disease characterized by ongoing degeneration of retinal photoreceptors that leads to gradual and irreversible vision loss over time. 1, 2, 3

Disease Progression Pattern

RP follows a characteristic progressive course that begins with night blindness (nyctalopia), advances to concentric visual field loss as peripheral photoreceptors degenerate, and ultimately results in bilateral central vision loss and potential complete blindness. 1, 3

• The disease primarily affects peripheral retina initially, with rod photoreceptors degenerating first, followed by cone photoreceptors in later stages 2, 3
• Progressive visual field constriction occurs as the disease advances from the periphery toward the central macula 1, 3
• RP is one of the leading causes of visual disability and blindness in people under 60 years old, affecting over 1.5 million people worldwide 1

Rate and Pattern of Progression

The progression is continuous and irreversible, though the rate varies depending on genetic subtype and inheritance pattern:

• Patients experience ongoing photoreceptor cell death that cannot be halted with current standard treatments 1, 4
• The heterogeneous genetic basis (39 loci implicated, 30 genes identified) means progression rates differ among patients, but all forms demonstrate progressive deterioration 2
• Visual function continues to decline over years to decades, with the timeline varying by specific genetic mutation and inheritance pattern (autosomal dominant, autosomal recessive, X-linked, or mitochondrial) 2, 3

Clinical Implications of Progressive Nature

The progressive nature of RP has profound implications for patient quality of life and management:

• Patients experience substantial impact on daily activities, social interactions, and employment as vision deteriorates 5
• Up to 13% of eyes with chronic conditions can progress to legal blindness (visual acuity 20/200 or worse) over time, though this statistic relates to central serous chorioretinopathy rather than RP specifically 6
• Current therapeutic options are limited to slowing progression rather than reversing damage, including vitamin A supplementation, protection from sunlight, visual aids, and management of ophthalmic comorbidities 1, 3

Current Treatment Landscape

The progressive nature underscores the urgent need for disease-modifying therapies:

• Only voretigene neparvovec (gene therapy) is FDA-approved, and only for the small subset of patients with confirmed RPE65 mutations 1
• Vitamin A supplements may help slow visual loss in certain common RP subtypes, but do not halt progression 3
• No curative treatment exists for the vast majority of RP patients, with management focused on rehabilitation programs and low-vision devices 1, 3

Emerging Therapeutic Approaches

Given the relentless progression, over 100 drugs are currently in development, with 50% being advanced therapy medicinal products (ATMPs):

• Gene therapies aim to rescue remaining photoreceptors before complete degeneration occurs, requiring viable target cells to be present 4, 5
• Cell therapies may offer broader application as they do not require the presence of viable photoreceptors and can potentially be used at later disease stages 5
• Therapeutic approaches targeting endoplasmic reticulum stress, apoptotic pathways, and oxidative stress are under investigation to slow photoreceptor degeneration 1

The progressive nature of RP makes early identification and timely diagnosis critical, as therapeutic interventions—particularly gene therapies—are most effective when photoreceptors are still present but not yet functional. 5