Question:medium
A patient presents with a gradual loss of night vision and peripheral vision. What is the most likely diagnosis based on fundoscopy findings?
A patient presents with a gradual loss of night vision and peripheral vision. What is the most likely diagnosis based on fundoscopy findings?
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In cases of gradual vision loss, especially with night blindness and peripheral vision loss, think of retinitis pigmentosa. Early diagnosis and genetic counseling are key.
Updated On: Jun 22, 2026
- Retinitis pigmentosa
- Retinal hemorrhage
- Diabetic retinopathy
- Hypertensive retinopathy
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The Correct Option is A
Solution and Explanation
Step 1: Read the symptom duo as a localiser.
Night blindness (nyctalopia) plus progressive loss of peripheral (mid-field) vision points to a primary rod photoreceptor dystrophy, because rods dominate scotopic and peripheral vision. This pattern, slowly progressive and often familial, names one classic disease.
Step 2: Connect to the fundus signature.
The disease is retinitis pigmentosa. Its triad on fundoscopy is: bone-spicule pigment clumping in the mid-peripheral retina, attenuated (thin) retinal arterioles, and a waxy pale optic disc; the ERG is markedly reduced. Each fundus feature corresponds to the rod loss producing the clinical nyctalopia and ring (tunnel) field constriction.
Step 3: Contrast with the vascular distractors.
• Diabetic retinopathy - microaneurysms, dot/blot haemorrhages, hard exudates, neovascularisation; central/variable vision change, not isolated early nyctalopia.
• Hypertensive retinopathy - arteriolar narrowing, AV nipping, flame haemorrhages, cotton-wool spots; tied to high BP, no bone spicules.
• Retinal haemorrhage - a focal finding, not a syndrome of progressive night/peripheral loss.
Step 4: Conclude.
Nyctalopia + peripheral field loss + bone-spicule pigmentation = RP.
Final Answer: Option 1 - Retinitis pigmentosa.
Night blindness (nyctalopia) plus progressive loss of peripheral (mid-field) vision points to a primary rod photoreceptor dystrophy, because rods dominate scotopic and peripheral vision. This pattern, slowly progressive and often familial, names one classic disease.
Step 2: Connect to the fundus signature.
The disease is retinitis pigmentosa. Its triad on fundoscopy is: bone-spicule pigment clumping in the mid-peripheral retina, attenuated (thin) retinal arterioles, and a waxy pale optic disc; the ERG is markedly reduced. Each fundus feature corresponds to the rod loss producing the clinical nyctalopia and ring (tunnel) field constriction.
Step 3: Contrast with the vascular distractors.
• Diabetic retinopathy - microaneurysms, dot/blot haemorrhages, hard exudates, neovascularisation; central/variable vision change, not isolated early nyctalopia.
• Hypertensive retinopathy - arteriolar narrowing, AV nipping, flame haemorrhages, cotton-wool spots; tied to high BP, no bone spicules.
• Retinal haemorrhage - a focal finding, not a syndrome of progressive night/peripheral loss.
Step 4: Conclude.
Nyctalopia + peripheral field loss + bone-spicule pigmentation = RP.
Final Answer: Option 1 - Retinitis pigmentosa.
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