Retinitis Pigmentosa & Fundoscopy Findings

Retinitis Pigmentosa (RP)

Pathophysiology

• Hereditary retinal degeneration affecting rod and cone photoreceptors

• Inherited in autosomal dominant (most common), autosomal recessive, or X-linked patterns

• Damaged rods lead to night blindness, then progressive peripheral vision loss

• Melanin migrates to peripheral retina (the classic ‘bone spicule’ appearance)

Presentation

• Early: Night blindness (nyctalopia), difficulty in dim light

• Progressive: Tunnel vision, eventual central vision decline

• Onset: Usually childhood to early adult years, slow progression

Fundoscopy

• Bone Spicule pigmentation in peripheral retina

• Optic Disc Pallor (waxy appearance)

• Attenuated (narrow) Retinal Vessels

Management

• No definitive cure; supportive measures:

  • Low-vision aids, orientation and mobility training

  • Genetic counselling for families

• Vitamin A high-dose supplementation: Limited evidence

• Investigational therapies: Gene therapy, retinal implants (in development)

Fundoscopy Findings: Other Retinal Conditions

Central Retinal Vein Occlusion (CRVO) — “Blood and Thunder”

• Diffuse retinal haemorrhages

• Tortuous, engorged veins

• Cotton-wool spots

• Macular oedema frequently present

• Often presents with sudden, painless vision loss

Central Retinal Artery Occlusion (CRAO) — “Cherry Red Spot”

• Pale retina (due to ischaemia), cherry-red fovea (macula)

• Attenuated retinal arterioles

• May have a preceding amaurosis fugax episode

• Emergency: Immediate ocular massage, consider stroke risk

Diabetic Retinopathy

• Microaneurysms

• Hard exudates, dot/blot haemorrhages, sometimes flame haemorrhages (in more severe changes)

• Neovascularisation in proliferative stage

• Advanced cases: Vitreous haemorrhage, tractional retinal detachment

Hypertensive Retinopathy

• Flame haemorrhages, cotton-wool spots (nerve fibre layer infarcts)

• AV Nicking (arteriovenous crossing changes)

• Silver-wiring or copper-wiring of arterioles in chronic hypertension

• Severe BP elevation → papilloedema