What is retinitis pigmentosa? Symptoms, causes & treatment

Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal degenerations characterized by progressive dysfunction and loss of rod photoreceptors followed by cones, leading to night blindness, peripheral visual field constriction (“tunnel vision”), and, later, central vision loss. Diagnosis is clinical with multimodal imaging, visual field testing, and full-field electroretinography; molecular genetic testing confirms the causative variant. There is no cure for most forms; management centers on complication control, low-vision rehabilitation, and gene therapy for select genotypes (eg, biallelic RPE65).

Key Points

• Retinitis pigmentosa is a rod-cone dystrophy with nyctalopia and peripheral field loss progressing over years to decades; onset and severity vary by genotype and inheritance pattern [1,2].
• Fundus shows bone spicule pigment, attenuated arterioles, and optic disc pallor; electroretinography demonstrates markedly reduced or nonrecordable rod responses [1].
• Genetic testing is central to diagnosis, prognostication, counseling, and eligibility for gene-specific therapy (eg, voretigene neparvovec for biallelic RPE65) [1,3].
• Common treatable complications include cystoid macular edema (CME) and posterior subcapsular cataract; carbonic anhydrase inhibitors for CME are off-label but often used [1,4].
• High-dose vitamin A is no longer routinely recommended due to mixed efficacy and safety concerns; high-dose vitamin E should be avoided [1].
• Early referral for low-vision services and orientation/mobility training preserves independence and safety.

Anatomy and Physiology

Photoreceptors reside in the outer retina: rods mediate scotopic (low-light) vision and peripheral fields; cones subserve photopic (daylight) acuity and color vision, concentrated in the fovea. The retinal pigment epithelium (RPE) supports photoreceptor outer segment turnover. Retinal function depends on intact photoreceptors, RPE phagocytosis, and choriocapillaris perfusion. Disruption of rod homeostasis leads secondarily to cone dysfunction.

Etiology

• Inherited pathogenic variants (>80 genes) affecting phototransduction, ciliary transport, the visual cycle, and outer segment structure [1,2].
• Common genes: RHO (autosomal dominant), USH2A and EYS (autosomal recessive), RPGR (X-linked) [1,2].
• Inheritance patterns
  • Autosomal dominant (AD): often later onset, slower progression.
  • Autosomal recessive (AR): variable onset, often moderate progression.
  • X-linked (XL): earlier onset, more rapid progression; female carriers may have mosaic changes and mild symptoms.
  • Mitochondrial and digenic forms are rare.
• Syndromic associations: Usher syndrome (RP with sensorineural hearing loss), Bardet–Biedl syndrome (RP with systemic features), Refsum disease (adult-onset RP with neuropathy and ataxia), others [1,2].

Pathophysiology

Primary rod dysfunction and apoptosis trigger secondary cone impairment via metabolic stress, oxidative injury, and loss of trophic support. Accumulated debris and RPE migration around retinal vessels create bone spicule pigmentation. Progressive arteriolar attenuation and optic disc “waxy” pallor reflect retinal atrophy. Macular changes—CME, epiretinal membrane, and atrophy—contribute to central acuity decline. In syndromic forms, shared ciliary dysfunction affects multiple organs.

Epidemiology

• Prevalence: approximately 1 in 4,000 in the United States and worldwide [2].
• Age at onset: childhood to early adulthood is typical; AD forms may present later [1].
• Sex: XL forms predominantly affect males; female carriers may be mildly affected.

Classification

• By photoreceptor involvement:
  • Typical RP (rod-cone dystrophy): rods affected first.
  • Cone-rod dystrophy (distinct entity): prominent early central vision loss and color deficits.
• By distribution: typical diffuse, sectoral RP (localized quadrants), pericentral RP (perifoveal ring), and sine pigmento (minimal pigmentation).
• By syndromic status: nonsyndromic vs syndromic (eg, Usher, Bardet–Biedl, Refsum).
• By inheritance: AD, AR, XL, mitochondrial, digenic.

Symptoms and Signs

• Typical RP (rod-cone dystrophy)
  • Symptoms: night blindness (nyctalopia), delayed dark adaptation, peripheral field loss (ring scotomas progressing to tunnel vision), photopsias; later, central blur and reading difficulty.
  • Signs: bone spicule-like pigment clumps in mid-periphery, narrowed arterioles, waxy pallor of optic disc; macular CME or epiretinal membrane on optical coherence tomography (OCT).
• Sectoral/pericentral RP
  • Symptoms: focal field defects corresponding to involved sectors; slower progression.
  • Signs: localized pigmentation and atrophy.
• Early-onset severe disease (including LCA spectrum)
  • Symptoms: nystagmus, poor visual behavior in infancy or early childhood.
  • Signs: markedly reduced or nonrecordable electroretinography (ERG); minimal initial pigment (sine pigmento).
• Syndromic RP
  • Usher syndrome: hearing loss (congenital in type 1; later-onset in type 2), vestibular dysfunction (type 1).
  • Bardet–Biedl: polydactyly, obesity, renal anomalies, hypogonadism.
  • Refsum disease: neuropathy, ataxia, elevated phytanic acid.

Complications

• Cystoid macular edema (CME).
• Posterior subcapsular cataract (PSC).
• Epiretinal membrane and vitreomacular traction.
• Photopsias and glare sensitivity.
• Depression, falls, and driving safety risks due to visual field loss.
• Rare: choroidal neovascularization in atypical phenotypes.

Diagnosis

Clinical evaluation

• History: onset of night vision problems, field constriction, photopsias; family history; consanguinity; systemic features (hearing, balance, neuropathy).
• Examination: visual acuity, color testing, confrontational and formal perimetry (Goldmann or Humphrey); dilated fundus examination documenting pigmentation pattern, vascular attenuation, and optic disc appearance.
• Counseling: inheritance patterns, natural history, and low-vision needs.

Imaging and laboratory testing

• Optical coherence tomography (OCT): outer retinal thinning, ellipsoid zone loss; detect CME or epiretinal membrane [1].
• Fundus autofluorescence (FAF): hyperautofluorescent ring indicating preserved photoreceptors; peripheral hypoautofluorescence with RPE loss [1].
• Full-field ERG: reduced/absent rod responses early; cone responses decline later; helps distinguish RP from stationary disorders [1].
• Kinetic/static visual fields: mid-peripheral ring scotomas progressing centripetally.
• Color fundus photography: baseline and progression documentation.
• Molecular genetic testing: next-generation sequencing panels or exome with copy-number analysis; confirm genotype and guide prognosis/therapy; refer to genetic counseling [1].
• Targeted systemic testing when syndromic disease suspected (eg, audiology for Usher; serum phytanic acid for Refsum before dietary therapy) [1].
• Exclude mimics if atypical (eg, serum vitamin A if malabsorption suspected before supplementation).

Differential diagnosis

Treatment

Medical management

• Gene therapy (on-label)
  • Voretigene neparvovec-rzyl (Luxturna): FDA-approved for patients ≥12 months with confirmed biallelic RPE65 mutations and viable retinal cells; improves functional vision and light sensitivity; delivered as a single subretinal injection per eye separated by days to weeks [3].
• Macular edema (off-label; evidence from small trials/series)
  • Topical carbonic anhydrase inhibitors: dorzolamide 2% one drop tid (three times daily) may reduce CME and improve acuity in some patients; monitor intraocular pressure and corneal health [4].
  • Oral acetazolamide 250 mg bid (twice daily), titrated to response/tolerability; adverse effects include paresthesias, fatigue, kidney stones; avoid in sulfonamide allergy and significant renal disease [4].
  • Topical nonsteroidal anti-inflammatory drugs or steroids have inconsistent benefit and steroid risks; reserved for select cases.
• Nutritional and lifestyle
  • High-dose vitamin A palmitate is not routinely recommended; if considered, specialist oversight with liver function and pregnancy avoidance is mandatory; avoid high-dose vitamin E (>400 IU/day) due to potential harm [1].
  • General nutrition, smoking cessation, and UV/bright-light protection for comfort; efficacy for disease modification is unproven [1,2].
• Low-vision rehabilitation
  • Early referral for magnification, contrast enhancement, field expansion aids, adaptive technology, and orientation/mobility training; occupational therapy for home/work adaptations.
• Comorbidity management
  • Treat depression/anxiety; assess fall risk; discuss driving restrictions based on visual fields per state law.

Procedural and surgical management

• Subretinal gene therapy delivery: pars plana vitrectomy with subretinal injection (CPT 67036 with add-on 67027 for subretinal pharmacologic injection) in qualified centers [3].
• Cataract surgery: phacoemulsification for PSC when visually significant; counsel on realistic gains (central acuity > fields); consider zonular support if weakness present [1].
• Vitreoretinal surgery: epiretinal membrane peel or relief of vitreomacular traction in symptomatic cases; individualize risk-benefit.
• Retinal prostheses: earlier FDA-cleared devices (eg, Argus II) are no longer in routine commercial use in the US; patients with legacy implants require specialized follow-up.

Special populations

• Pediatric: monitor growth, school function, and development; evaluate for syndromic features (audiology for Usher); prioritize genetic testing and family counseling; consider eligibility windows for gene therapy (RPE65).
• Pregnancy/lactation: avoid high-dose vitamin A (teratogenic); avoid or use caution with systemic acetazolamide (generally avoided unless benefits outweigh risks); discuss contraception if any teratogenic agent is contemplated [1,3,4].
• Elderly: address polypharmacy, fall prevention, and low-vision support; cataract surgery planning requires realistic goal-setting.

Prognosis

Progressive visual field constriction is typical; central acuity often remains serviceable into mid-adulthood in AD/AR forms but declines earlier in XL disease. Rate of ERG decline and field loss varies by genotype and phenotype [1,2]. Treating CME and cataract may improve central acuity. Gene therapy for biallelic RPE65 can improve functional vision in appropriate candidates but does not halt all progression [3]. Lifelong low-vision support remains essential.

Prevention and Patient Counseling

• RP cannot be prevented, but cascade genetic testing and counseling inform family planning (including prenatal and preimplantation options).
• Encourage protective eyewear in bright light, smoking cessation, physical activity, and management of systemic comorbidities.
• Avoid megadose vitamin E; discuss uncertainties around supplements before use.
• Plan for education, career, and mobility adaptations early; connect patients with state blindness services and support groups.
• Syndromic surveillance (audiology, renal assessment when indicated) and coordination with genetics and primary care.

When to Seek Immediate Care

• Sudden partial or complete vision loss in one or both eyes.
• New shower of floaters, flashes of light, or a dark curtain in vision (possible retinal tear/detachment).
• Severe eye pain, redness, or light sensitivity, especially after eye surgery.
• Rapid worsening of central vision or distortion.
• Head injury with any change in vision.

References

1. American Academy of Ophthalmology Retina/Vitreous Panel. Preferred Practice Pattern: Inherited Retinal Degenerations. AAO; 2022. https://www.aao.org/preferred-practice-pattern/inherited-retinal-degenerations-ppp
2. National Eye Institute. Retinitis Pigmentosa. NEI; 2024. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/retinitis-pigmentosa
3. U.S. Food and Drug Administration. Luxturna (voretigene neparvovec-rzyl) Prescribing Information. Updated 2023. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/125610s###lbl.pdf
4. Fishman GA, Apushkin MA. Continued use of dorzolamide for the treatment of cystoid macular edema in patients with retinitis pigmentosa. Br J Ophthalmol. 2007;91(6):743-745. doi:10.1136/bjo.2006.112847
5. Hariri AH, Velaga SB, Girach A, et al. Cystoid macular edema in retinitis pigmentosa: Prevalence, pathophysiology, and treatment. Surv Ophthalmol. 2022;67(6):1514-1530. doi:10.1016/j.survophthal.2022.03.009
6. Verbakel SK, van Huet RAC, Boon CJF, et al. Non-syndromic retinitis pigmentosa. Prog Retin Eye Res. 2018;66:157-186. doi:10.1016/j.preteyeres.2018.03.005
7. Dias MF, Joo K, Kemp JA, et al. Molecular genetics and emerging therapies for retinitis pigmentosa: Basic research and clinical perspectives. Prog Retin Eye Res. 2018;63:107-131. doi:10.1016/j.preteyeres.2017.10.004
8. StatPearls. Retinitis Pigmentosa. Updated 2024. https://www.ncbi.nlm.nih.gov/books/NBK519518/
9. EyeWiki. Retinitis Pigmentosa. American Academy of Ophthalmology. https://eyewiki.org/Retinitis_Pigmentosa
10. Hoffman DR, Hughbanks-Wheaton DK, Fish GE, et al. Relation between dietary intake and serum levels of lutein and zeaxanthin in RP patients enrolled in a clinical trial of vitamin A. Arch Ophthalmol. 2006;124(11):1653-1658. doi:10.1001/archopht.124.11.1653

Disclaimer: This article is for informational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified eye care professional about your specific condition. If you have sudden vision loss, severe eye pain, or an eye injury, seek emergency care immediately.