Retinitis pigmentosa (RP)

What changes during this transition

Retinitis pigmentosa is a family of inherited retinal dystrophies — monogenic, progressive, characterized by primary rod photoreceptor degeneration followed by cone loss, with bone-spicule pigmentary changes on fundus exam and reduced or extinguished scotopic and photopic responses on full-field ERG. More than 100 causative genes have been identified across autosomal dominant (RHO is the prototypical example), autosomal recessive (USH2A, EYS, RPE65, CEP290, others), and X-linked (RPGR is the dominant X-linked gene, with RP2 also implicated) inheritance patterns. Non-syndromic RP is the most common presentation; syndromic forms include Usher syndrome (RP plus sensorineural hearing loss; the most common cause of combined deaf-blindness), Bardet-Biedl syndrome (RP plus central obesity, polydactyly, renal dysfunction, hypogonadism, cognitive features), Refsum disease (phytanic acid accumulation, treatable with dietary modification), Kearns-Sayre syndrome, neuronal ceroid lipofuscinoses, and others. Roughly 1 in 4,000 individuals globally are affected. Average age of symptomatic onset varies dramatically by gene — Leber congenital amaurosis (LCA) variants including CEP290 and RPE65-LCA present in infancy; classic non-syndromic RP often presents in adolescence or early adulthood with nyctalopia (night blindness), followed by progressive peripheral visual-field loss with eventual central vision involvement; some milder variants present in middle age. The natural history is progressive but heterogeneous — disease stage and rate are gene-specific. Genetic testing is the load-bearing precondition for nearly every standard-of-care decision in RP — it is not optional, and the editorial register on this axis must place it ahead of any other intervention conversation. Comprehensive next-generation sequencing panels covering the 100+ known RP genes drive: (1) Luxturna (voretigene neparvovec, Spark Therapeutics, FDA approved December 2017; EMA approved November 2018) eligibility, which is restricted to patients with confirmed biallelic RPE65 mutations — a small subset of RP but the prototypical successful subretinal AAV gene therapy; (2) sepofarsen Phase 3 trial eligibility for the CEP290 c.2991+1655A>G LCA10 splice mutation (ProQR / Laboratoires Théa antisense oligonucleotide intravitreal program); (3) ongoing AAV gene-therapy pipeline enrollment across jurisdictions — RPGR programs (4D Molecular Therapeutics 4D-125, AGTC, MeiraGTx), USH2A programs, RHO programs, others; (4) family counseling for inheritance pattern and reproductive decision-making; (5) genotype-specific prognosis. The Foundation Fighting Blindness (FFB) maintains the patient-facing trial registry (My Retina Tracker), the genetic-testing-access program (Open Access), the patient resource network, and the field's primary research-funding pipeline — FFB referral is editorially load-bearing on this axis as the actionable user-side resource. The rest of the standard-of-care toolkit. Low-vision rehabilitation is the foundation across all stages — orientation and mobility training, optical and electronic low-vision aids, screen-reader and adaptive-technology training, occupational therapy, vocational rehabilitation, driving assessment and cessation guidance, and patient and family psychological support. Argus II retinal prosthesis (Second Sight) was the historical reference for severe end-stage RP — FDA Humanitarian Device Exemption 2013, EMA CE Mark 2011, commercially discontinued 2019 after Second Sight's pivot. The Prima System (Pixium Vision / Science Corporation) photovoltaic subretinal implant is in clinical trials. Tinlarebant (LBS-008, Belite Bio) is in Phase 3 for Stargardt and adjacent inherited retinal dystrophies. CNTF intravitreal implant (NT-501, Neurotech) was characterized by Sieving's group (PNAS 2006) with mixed signals for RP. Vitamin A palmitate 15,000 IU/day (Berson et al., NEJM 1993) remains in some IRD clinical use as a slowing-of-progression intervention despite subsequent reanalysis controversy and concerns about hepatotoxicity at long-term dosing; the protocol is IRD-specialist-managed with periodic LFT and serum retinol monitoring, and is not appropriate for pregnant women or those with liver disease. DHA omega-3 supplementation has signal as adjunct in some cohorts. Lutein supplementation has signal from the Bahrami 2006 small randomized trial. N-acetylcysteine (NAC) is in active investigation through the N-CARP trial (Campochiaro group, Wilmer Eye Institute). The critical contraindication editorial point. HIGH-DOSE VITAMIN E IS SPECIFICALLY CONTRAINDICATED IN RP — Berson 1993 NEJM (the same trial that introduced vitamin A palmitate 15,000 IU/day) showed accelerated visual-field loss in the vitamin E 400 IU/day arm. This is one of the few axes in the library where a common adjunct supplement is documented to cause HARM in the disease, and any supplement-stacking decision in RP carries trial-tested risk signals that adjacent indications do not. The 'more antioxidants is better' assumption is NOT the rule in RP. Where Juno's library fits — narrowly and with deliberate non-elevation. No peptide in the library has a discovery-card-defensible RP case. The five drafted substrate entries (SS-31, NMN, BPC-157, TB-500, GHK-Cu) exist for honest /ask answers when users probe specific compounds, not for browse elevation. SS-31 / elamipretide has the most mechanistically defensible case (RPE and photoreceptor mitochondrial dysfunction is real and central to the secondary cell-death cascade), but there is no published SS-31 RP trial in any jurisdiction, the Barth syndrome FDA approval (March 2025) does not propagate per Rule 6, the LHON exploration is a different mitochondrial optic neuropathy, and the closest ophthalmic neighbor (ReCLAIM-2 Phase 2b in geographic atrophy) missed its primary endpoint December 2023. NMN sits adjacent to the nicotinamide-for-glaucoma trial program with two extrapolation steps (salvage-pathway substitution plus glaucoma-to-RP indication propagation) and zero NMN RP trials. BPC-157 and TB-500 both carry documented VEGF / angiogenic activity that is mechanistically opposed to anti-VEGF intervention for the cystoid macular edema (CME) subset common in advanced RP, and for the diabetic retinopathy / DME / RVO / wet-AMD overlap subsets — load-bearing safety thread for those users. GHK-Cu's case is the most extrapolation-distant — copper-binding antioxidant cosmetic-dermatology peptide with no retinal model in any species, complicated by the Berson 1993 supplement-stacking caution and the copper-additive question. The honest editorial frame: IRD-specialist coordination, genetic testing, gene-therapy referral, Foundation Fighting Blindness trial-registry placement, and low-vision rehabilitation drive outcomes; no peptide in the library substitutes.