Retinitis pigmentosa: what has really changed, and what hasn’t

You’ve just been told that you, or your child, have retinitis pigmentosa, or an inherited retinal dystrophy. Three words have stuck: genetic, incurable, blindness. The first two are accurate; the third deserves discussion. No treatment cures these diseases today. But the landscape has shifted for good: genetic diagnosis has become useful, a gene therapy is approved for one specific situation, and two common complications are treatable and often bring real gains in vision. Here is what is established, what is not, and what can be done right now.

UNDERSTANDING

“Retinitis pigmentosa” denotes a group, not one disease

The term covers a group of inherited dystrophies that share a single mechanism: the progressive degeneration of the photoreceptors of the retina — first the rods, which are responsible for vision in low light and peripheral vision, then the cones, which handle central vision and colour. This order — rods first, cones second — explains the whole pattern of symptoms and their timing.

More than 80 genes have been linked to the non-syndromic forms, across every mode of inheritance: autosomal dominant, autosomal recessive, and X-linked. The electroretinogram is markedly reduced, sometimes extinguished; OCT and fundus autofluorescence show a progressive loss of the outer layers. Two people with the same diagnosis on their medical report can therefore have genetically distinct diseases that progress differently.

The reference reviews put the worldwide prevalence at around one person in 4,000. This figure is repeated from one article to the next as a global estimate, with no reference population specified, and none of my sources provide French data: it is an order of magnitude, not a measurement. Unlike AMD, these diseases begin in the periphery, and much earlier in life.

EARLY SIGNS

Why the diagnosis often takes years to arrive

Because the first symptom doesn’t look like an eye problem. Difficulty seeing in the dark — night blindness, or nyctalopia — sets in slowly: it takes longer to adjust when entering a dark room, and people start avoiding night driving. Most people put it down to tiredness or age. In a Chinese cohort focused on the CNGA1 gene, night blindness was the initial symptom in every patient, with onset in childhood in 88% of cases.

The second symptom is more subtle: the visual field narrows concentrically, with no perceived blind spot. The brain fills the gap, and patients only notice when they bump into objects or lose sight of people to the side. Throughout this time, visual acuity measured at distance can remain excellent, because the macula is spared. A quick examination, without visual field testing or a dilated peripheral retinal exam, can easily miss it.

Age of onset depends on the mode of inheritance. In an Italian series of 591 patients, the mean age of onset was 13.9 years in X-linked forms, 18.9 years in Usher syndrome, 19.3 years in dominant forms and 23.2 years in recessive forms — averages that guide expectations without predicting any individual case.

GENETICS

Genetic testing: what’s the point if no treatment exists?

To four concrete things, none of which assumes that a treatment exists. It names the disease and ends the diagnostic odyssey. It refines the prognosis, which depends on the gene. It allows for reliable genetic counselling for siblings and children. And it determines entry into a clinical trial, as well as access to the only approved treatment — both of which are defined by the gene, not by the clinical diagnosis.

The yield is substantial but not complete. A study of 800 Chinese families with non-syndromic dystrophies identified the cause in 60.1% of cases; the Israeli national consortium resolved 56% of families; a Japanese cohort of 1,204 patients reached a molecular diagnosis in 29.6% of them. In the Italian series already cited, the yield reached 55.2% when there was a family history, but fell to 37.4% once isolated cases were included.

A negative test does not mean “no genetic disease”: it means that the technique used at that point in time did not find one. A Swedish team retested 279 patients whose earlier tests had been inconclusive, and confirmed a genotype in some of them using an expanded panel. The genes involved also differ by country: in an Italian cohort of 2,790 patients, of whom 2,036 had a molecular diagnosis, ABCA4 accounted for 26.3% of resolved cases, USH2A for 11.2% and RPGR for 5.0%.

SYNDROMES

When the retina isn’t the only thing affected

Between 20% and 30% of patients with retinitis pigmentosa have an extra-ocular manifestation, as part of a syndrome. That is a large enough proportion to warrant systematically asking about hearing, balance, weight, kidney function and development, even when the eye appears to be the only thing involved.

Usher syndrome is the most common: it combines deafness with retinal dystrophy, and sometimes balance problems due to vestibular involvement. Nine genes have been identified, grouped into three clinical types, all autosomal recessive; type I is the most severe, type II the most common. A French cohort of 231 patients showed that the two major genes, MYO7A and USH2A, still regularly yield variants that have never been described before.

The other presentations are rarer but numerous: Bardet-Biedl syndrome and other ciliopathies, inherited metabolic diseases, mitochondrial disorders. One situation stands apart because it is misleading: certain dystrophies, particularly those linked to the CRB1 gene, can first present as uveitis, with the inflammation being what leads to the diagnosis.

PROGRESSION

How fast does it progress?

There is no single answer, and giving a patient an age at which they will go blind is one of the worst disservices you can do them. The speed depends on the gene, the variant, and poorly understood factors that cause two people in the same family to diverge. What can be measured are medians by genotype, published in recent years to sharpen the counselling given in consultation.

In a multicentre series of 100 patients carrying a mutation in the RHO gene, the median age for reaching a central visual field of less than 20° was 52 years, and 79 years for a field of less than 10°. A quarter of these patients had a so-called sectorial form, limited to part of the retina, which progresses markedly more slowly.

Other benchmarks, all genotype-specific. For the CNGA1 gene, the visual field narrowed to 10° or less at a median age of 39.4 years; in X-linked forms, a systematic review puts annual progression at between 4% and 19%, depending on the marker. Two parameters serve as follow-up benchmarks: the width of the ellipsoid zone on OCT, which reflects the area of still-functioning photoreceptors, and the implicit time of the 30-Hz flicker electroretinogram, an independent predictor of the speed of progression.

GENE THERAPY

Gene therapy: what it treats, and what it doesn’t

This is where articles aimed at the general public become misleading. An approved gene therapy does exist — voretigene neparvovec — but its indication is not “retinitis pigmentosa”: it is limited to carriers of two mutations in the RPE65 gene, one on each copy. To put this in scale: in the Italian cohort of 2,036 patients with a confirmed molecular diagnosis, RPE65 accounted for 2% of cases. The very large majority of patients therefore do not fall within this indication, and no other gene has an approved treatment.

For those who do qualify, the benefit is real. The phase 3 trial included 31 participants; one year after the subretinal injection, performance on a multi-luminance mobility test improved by an average of 1.8 light levels, compared with 0.2 in the control group, and 13 of the 20 treated participants passed the course at the lowest light level tested, something no control participant achieved. These gains are maintained at 3 and 4 years.

It’s also important to say what real-world experience has revealed that the trials had not seen: chorioretinal atrophy develops in a substantial proportion of treated patients, including at sites away from the injection point, and its long-term functional significance remains uncertain. Paediatric case series report transient intraocular inflammation and pressure rises that have sometimes required surgery. The benefit is mainly in low-light vision and mobility independence, less in lines of visual acuity.

Everything else remains at the research stage: viral vectors for other genes, genome editing, exon skipping using antisense oligonucleotides — under evaluation in Usher syndrome type 2A — optogenetics, neuroprotection. None of my sources cover access, pricing or reimbursement conditions in France: those are questions for the reference centre following you, not for an article.

PROSTHESES

Retinal prostheses: where does this approach actually stand?

Lower than it stood ten years ago, and it would be dishonest to present it otherwise. A 2023 review identified thirteen devices, six of them in active clinical trials and four discontinued — among the latter, the Argus II and the Alpha IMS and AMS implants, which had nonetheless held marketing authorisation in Europe or the United States. The reasons are not purely technical: the time needed to observe an outcome, the absence of validated measures, unknown long-term effects, funding, and the small number of eligible patients.

What these devices actually restored deserves precise description, because the phrase “bionic eye” is misleading. The Argus II, implanted in more than a hundred people, electrically stimulated the inner retinal cells that were still present, using a camera mounted on a pair of glasses. Patients improved on orientation, target localisation and shape recognition, and some on reading short words, with considerable variability. This is not restored vision but structured light perception, which requires learning to use.

There is also a biological obstacle: prolonged visual deprivation reorganises the retina and then the visual areas of the brain. The implant therefore delivers artificial signals to a system that has already been remodelled, which partly explains why two patients fitted with the same device do not get the same result.

MACULAR OEDEMA

Cystoid macular oedema: the complication that, unlike the disease itself, can be treated

This is the single most useful point in this entire article. About a quarter of patients with retinitis pigmentosa develop cystoid macular oedema: fluid builds up in the macula and blurs central vision — the very vision that had remained preserved. A drop in central vision is therefore not necessarily the disease advancing: sometimes it is a treatable complication, and this complication shows up on an OCT scan.

Systematic reviews agree on first-line treatment: carbonic anhydrase inhibitors, given orally or as eye drops, reduce central macular thickness and improve vision in a proportion of patients, with oral acetazolamide having the strongest clinical evidence base. Local corticosteroids are also effective; anti-VEGF results vary between studies. Recurrence after improvement is common, whatever the treatment, and does not represent a failure of care.

The level of evidence remains modest: the available studies involve small numbers of patients and are methodologically uneven, as their own authors point out. This does not mean treatment should be withheld — it means the effect needs to be measured in each patient. Frequency also depends on genotype: in the series focused on the PDE6A gene, oedema was present in more than half of eyes at the very first assessment.

CATARACT

Cataract: early, common, and operable

A second accessible gain. Retinitis pigmentosa is accompanied by a particular type of cataract — posterior subcapsular — positioned just in front of the retina, directly in the path of light rays: even a modest opacity produces disproportionate glare there. And it appears early. In a British database of 113,389 operated eyes, the average age of patients with retinitis pigmentosa at the time of surgery was 57, compared with 75 for eyes with no associated pathology.

Surgery improves vision in the majority of patients. In a European series of 295 eyes, corrected acuity improved on average from 1.03 to 0.81 logMAR in the first eye operated on, and 39% of patients had a gain the authors describe as marked. The main prognostic factor is not the cataract but the state of the macula: a Japanese study with almost six years of follow-up shows that the gain is maintained if the foveal ellipsoid zone is preserved, much less so if it is not.

The surgery has particular features that justify planning ahead: the zonule, the network of fibres that suspends the lens, is frequently fragile — abnormal lens mobility was found in 18.8% of eyes in one series — which can call for a capsular tension ring to be fitted. Posterior capsule opacification is then very common, and is managed with a YAG laser. Finally, postoperative macular oedema occurred in 6.9% of eyes with retinitis pigmentosa, compared with 1% of control eyes: this calls for closer monitoring, not a decision to forgo surgery.

SUPPLEMENTS

Should you take vitamin A?

No, the current data do not support it — and you will not find any dosage in this article, deliberately. The subject deserves to be presented for what it is: a debate that has shifted over time, not a recommendation that fits in one sentence.

The story goes back to a randomised trial conducted from 1984 to 1992, which concluded that vitamin A had a favourable effect and vitamin E an unfavourable one. In 2023, sequencing of the stored samples allowed these results to be reanalysed taking genotype into account: the harmful effect of vitamin E was confirmed, but the beneficial effect of vitamin A was no longer detectable across the cohort as a whole.

The report published in 2025 by the American Academy of Ophthalmology reviewed fifteen studies on vitamin A, DHA, lutein, vitamin E and other compounds. Its conclusion is clear: no good-quality evidence supports supplementation, with favourable signals most often coming from secondary endpoints or post hoc analyses. A Cochrane review and a review of randomised trials reach the same conclusion. N-acetylcysteine is the subject of a phase 3 trial: this is ongoing research, not a treatment.

The gap with actual practice is striking: in a 2025 survey of 50 patients at a specialist Italian centre, 52% were taking a supplement, 84.6% of them vitamin A, and every single respondent was unaware of the current state of the evidence. If you are already taking something, do not stop on the strength of an article: talk to the ophthalmologist following you, and bring the box with you.

DAILY LIFE

What changes daily life without curing the disease

Low-vision rehabilitation is what changes daily life the most for the majority of patients. It restores nothing, but it reorganises the use of what remains: home lighting, tinted filters against glare, magnifying aids and digital tools for reading, mobility training, and workstation adaptation. It works best when started early, rather than at the stage when everything has become difficult.

The stakes are not only practical. A review of systematic reviews on eye health shows an association between visual impairment and a decline in quality of life, and documents the effect of ophthalmological interventions on this dimension. The psychological and social impact is part of the care.

That leaves the question almost every patient asks: what is the point of regular follow-up when there is no treatment? Three things. Screening for macular oedema and cataract, which can cause the loss of recoverable vision. Updating the genetic diagnosis, because panels keep expanding, and a test that was inconclusive ten years ago can succeed today. And knowing, when the time comes, whether your gene is among those for which a trial is recruiting.

Frequently asked questions

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Scientific sources

• Verbakel SK, van Huet RAC, Boon CJF, et al. Non-syndromic retinitis pigmentosa. Prog Retin Eye Res. 2018;66:157-186. PMID 29597005
• Karuntu JS, Almushattat H, Nguyen XT, et al. Syndromic retinitis pigmentosa. Prog Retin Eye Res. 2025;107:101324. PMID 39733931
• Livingston CA, Weng CY, Chancellor JR. Retinitis Pigmentosa and Therapeutic Candidates. Int Ophthalmol Clin. 2025;65(1):17-21. PMID 39710900
• Huckfeldt RM, Comander J. Management of Cystoid Macular Edema in Retinitis Pigmentosa. Semin Ophthalmol. 2017;32(1):43-51. PMID 27748628
• Liu Y, Zhang D, Zhou Y, et al. Natural History of CNGA1-Associated Retinitis Pigmentosa in a Large Chinese Cohort Revealing an Optimal Intervention Window. Am J Ophthalmol. 2026;283:299-312. PMID 41448483
• Nguyen XT, Talib M, van Cauwenbergh C, et al. Clinical characteristics and natural history of RHO-associated retinitis pigmentosa: a long-term follow-up study. Retina. 2021;41(1):213-223. PMID 32301896
• Zada M, Cornish EE, Fraser CL, et al. Natural history and clinical biomarkers of progression in X-linked retinitis pigmentosa: a systematic review. Acta Ophthalmol. 2021;99(5):499-510. PMID 33258268
• Hashem SA, Georgiou M, Wright G, et al. PDE6A-associated retinitis pigmentosa, clinical characteristics, genetics, and natural history. Ophthalmol Retina. 2025;9(3):278-287. PMID 39218074
• Georgiou M, Grewal PS, Narayan A, et al. Sector retinitis pigmentosa: extending the molecular genetics basis and elucidating the natural history. Am J Ophthalmol. 2021;221:299-310. PMID 32795431
• Comander J, Weigel-DiFranco C, Sanderson K, et al. Natural history of retinitis pigmentosa based on genotype, vitamin A/E supplementation, and an electroretinogram biomarker. JCI Insight. 2023;8(15):e167546. PMID 37261916
• Liu X, Tao T, Zhao L, et al. Molecular diagnosis based on comprehensive genetic testing in 800 Chinese families with non-syndromic inherited retinal dystrophies. Clin Exp Ophthalmol. 2021;49(1):46-59. PMID 33090715
• Sharon D, Ben-Yosef T, Goldenberg-Cohen N, et al. A nationwide genetic analysis of inherited retinal diseases in Israel as assessed by the Israeli inherited retinal disease consortium. Hum Mutat. 2020;41(1):140-149. PMID 31456290
• Koyanagi Y, Akiyama M, Nishiguchi KM, et al. Genetic characteristics of retinitis pigmentosa in 1204 Japanese patients. J Med Genet. 2019;56(10):662-670. PMID 31213501
• Colombo L, Maltese PE, Castori M, et al. Molecular epidemiology in 591 Italian probands with nonsyndromic retinitis pigmentosa and Usher syndrome. Invest Ophthalmol Vis Sci. 2021;62(2):13. PMID 33576794
• Karali M, Testa F, Di Iorio V, et al. Genetic epidemiology of inherited retinal diseases in a large patient cohort followed at a single center in Italy. Sci Rep. 2022;12(1):20815. PMID 36460718
• Jespersgaard C, Fang M, Bertelsen M, et al. Molecular genetic analysis using targeted NGS analysis of 677 individuals with retinal dystrophy. Sci Rep. 2019;9(1):1219. PMID 30718709
• Areblom M, Kjellström S, Andréasson S, et al. A description of the yield of genetic reinvestigation in patients with inherited retinal dystrophies and previous inconclusive genetic testing. Genes (Basel). 2023;14(7):1413. PMID 37510321
• Castiglione A, Möller C. Usher syndrome. Audiol Res. 2022;12(1):42-65. PMID 35076463
• Mansard L, Baux D, Vaché C, et al. The study of a 231 French patient cohort significantly extends the mutational spectrum of the two major Usher genes MYO7A and USH2A. Int J Mol Sci. 2021;22(24):13294. PMID 34948090
• Forsythe E, Beales PL. Bardet-Biedl syndrome. Eur J Hum Genet. 2013;21(1):8-13. PMID 22713813
• Hung JH, Jain T, Khatri A, et al. Inherited retinal disease-associated uveitis. Surv Ophthalmol. 2025;70(5):951-981. PMID 40157547
• Russell S, Bennett J, Wellman JA, et al. Efficacy and safety of voretigene neparvovec (AAV2-hRPE65v2) in patients with RPE65-mediated inherited retinal dystrophy: a randomised, controlled, open-label, phase 3 trial. Lancet. 2017;390(10097):849-860. PMID 28712537
• Maguire AM, Russell S, Chung DC, et al. Durability of voretigene neparvovec for biallelic RPE65-mediated inherited retinal disease: phase 3 results at 3 and 4 years. Ophthalmology. 2021;128(10):1460-1468. PMID 33798654
• Li JXL, Rowson AC, Naji L, Li S, Simunovic MP. Post-approval outcomes of voretigene neparvovec retinal gene therapy: a systematic review and meta-analysis. Surv Ophthalmol. 2026. PMID 42425207
• Thompson DA, De Smit E, Tan W, Handley SE, Marmoy OR, Henderson RH. Vision outcomes in children treated with voretigene neparvovec for RPE65-associated retinopathy. JAMA Ophthalmol. 2026;144(2):156-165. PMID 41481309
• Daruich A, Rateaux M, Batté E, et al. 12-month outcomes after voretigene neparvovec gene therapy in paediatric patients with RPE65-mediated inherited retinal dystrophy. Br J Ophthalmol. 2025;109(2):281-285. PMID 39578019
• Kiraly P, Cottriall CL, Taylor LJ, et al. Outcomes and adverse effects of voretigene neparvovec treatment for biallelic RPE65-mediated inherited retinal dystrophies in a cohort of patients from a single center. Biomolecules. 2023;13(10):1484. PMID 37892166
• Bommakanti N, Young BK, Sisk RA, et al. Classification and growth rate of chorioretinal atrophy after voretigene neparvovec-rzyl for RPE65-mediated retinal degeneration. Ophthalmol Retina. 2024;8(1):42-48. PMID 37660736
• Lonfat N, Moreno-Leon L, Punzo C, Khanna H. Update on gene therapy clinical trials for eye diseases. Hum Gene Ther. 2025;36(19-20):1287-1300. PMID 40965251
• Brar AS, Parameswarappa DC, Takkar B, et al. Gene therapy for inherited retinal diseases: from laboratory bench to patient bedside and beyond. Ophthalmol Ther. 2024;13(1):21-50. PMID 38113023
• Mauriac SA, Lee J, Zhang J, et al. AAV-mediated exon skipping therapy for Usher syndrome, type 2A. Mol Ther. 2026;34(1):179-202. PMID 40994011
• Ramirez KA, Drew-Bear LE, Vega-Garces M, et al. An update on visual prosthesis. Int J Retina Vitreous. 2023;9(1):73. PMID 37996905
• Luo YH, da Cruz L. The Argus II retinal prosthesis system. Prog Retin Eye Res. 2016;50:89-107. PMID 26404104
• Finn AP, Grewal DS, Vajzovic L. Argus II retinal prosthesis system: a review of patient selection criteria, surgical considerations, and post-operative outcomes. Clin Ophthalmol. 2018;12:1089-1097. PMID 29942114
• Bloch E, Luo Y, da Cruz L. Advances in retinal prosthesis systems. Ther Adv Ophthalmol. 2019;11:2515841418817501. PMID 30729233
• Caravaca-Rodriguez D, Gaytan SP, Suaning GJ, et al. Implications of neural plasticity in retinal prosthesis. Invest Ophthalmol Vis Sci. 2022;63(11):11. PMID 36251317
• Chen C, Liu X, Peng X. Management of cystoid macular edema in retinitis pigmentosa: a systematic review and meta-analysis. Front Med (Lausanne). 2022;9:895208. PMID 35652079
• Bakthavatchalam M, Lai FHP, Rong SS, et al. Treatment of cystoid macular edema secondary to retinitis pigmentosa: a systematic review. Surv Ophthalmol. 2018;63(3):329-339. PMID 28987613
• Parodi MB, Iacono P, Da Pozzo S. Anti-VEGF and retinal dystrophies. Curr Drug Targets. 2020;21(12):1201-1207. PMID 32342816
• Georgiou M, Shakarchi AF, Elhusseiny AM, Michaelides M, Sallam AB. Cataract surgery outcomes in retinitis pigmentosa: a comparative clinical database study. Am J Ophthalmol. 2024;262:34-39. PMID 38311153
• Nguyen XT, Thiadens AAHJ, Fiocco M, et al. Outcome of cataract surgery in patients with retinitis pigmentosa. Am J Ophthalmol. 2023;246:1-9. PMID 36252678
• Dikopf MS, Chow CC, Mieler WF, et al. Cataract extraction outcomes and the prevalence of zonular insufficiency in retinitis pigmentosa. Am J Ophthalmol. 2013;156(1):82-88. PMID 23628349
• Nakamura S, Fujiwara K, Yoshida N, et al. Long-term outcomes of cataract surgery in patients with retinitis pigmentosa. Ophthalmol Retina. 2022;6(4):268-272. PMID 34923176
• Hong Y, Li H, Sun Y, et al. A review of complicated cataract in retinitis pigmentosa: pathogenesis and cataract surgery. J Ophthalmol. 2020;2020:6699103. PMID 33489339
• Jain N, Maguire MG, Flaxel CJ, et al. Dietary supplementation for retinitis pigmentosa: a report by the American Academy of Ophthalmology. Ophthalmology. 2025;132(3):354-367. PMID 39453328
• Schwartz SG, Wang X, Chavis P, et al. Vitamin A and fish oils for preventing the progression of retinitis pigmentosa. Cochrane Database Syst Rev. 2020;6(6):CD008428. PMID 32573764
• Sacchetti M, Mantelli F, Merlo D, et al. Systematic review of randomized clinical trials on safety and efficacy of pharmacological and nonpharmacological treatments for retinitis pigmentosa. J Ophthalmol. 2015;2015:737053. PMID 26339504
• Barthelemy N, Lee W, Gregori NZ, Lam BL, Sengillo JD. Nutritional supplements: current evidence for retinitis pigmentosa and Stargardt disease. Curr Opin Ophthalmol. 2026;37(3):205-214. PMID 41861379
• Ruggeri ML, Quarta A, Lorenzi C, et al. Vitamins and retinitis pigmentosa: a single-center survey from an Italian cohort. Ther Adv Ophthalmol. 2026;18. PMID 42011186
• Assi L, Chamseddine F, Ibrahim P, et al. A global assessment of eye health and quality of life: a systematic review of systematic reviews. JAMA Ophthalmol. 2021;139(5):526-541. PMID 33576772

This article is intended for information purposes and does not replace a medical consultation. Indications, expected benefits and risks depend on each individual situation. For any question concerning your vision, consult an ophthalmologist.