Vitreo-retinal: Retinal Detachment

Question 1

What are floaters and photopsia

Answer 1

Floaters

Photopsia (flashing light)

Question 2

What are causes of floaters

Answer 2

Blood - Vitreous haemorrhage
Cells - Anterior,intermediate, posterior uveitis
Collapsed vitreous - high myopia, old age

Question 3

What are causes of photopsia and why does it occur

Answer 3

Retinal tear
Retinal detachment
Vitreous detachment

Mechanical stimulation of photoreceptors in retina

Question 4

What is the significance of floaters/photopsia

Answer 4

Common - esp w old age and high myopia

New flurry of floaters/photopsia - requires urgent referral

Question 5

What is Posterior Vitreous Detachment

Answer 5

Vitreous gel separates from posterior retina

Question 6

What are causes of PVD

Answer 6

Trauma
Old age - fluid collects bw retina + vitreous membrane
High myopia

Question 7

What are clinical features of PVD

Answer 7

Floaters - ‘cobweb’, due to haemorrhage or collapsed vitreous
Photopsia

Question 8

What is the natural history of floaters

Answer 8

Common
Majority self-limiting + low risk of retinal detachment
Acute PVD with flurry of floaters - risk of rhegmatogenous retinal detachment

Question 9

Management of PVD

Answer 9

Slit-lamp examination - look for retinal tear
No retinal tear: reassurance
Retinal tear: Laser Retinopexy - to seal retinal tear, prevent retinal detachment

Question 10

What is retinal detachment

Answer 10

Retina separates from retinal pigment epithelium due to sub-retinal fluid
When retina separates from blood supply, photoreceptors slowly degenerate, becoming permanently non-functional

Question 11

What are the types of retinal detachment

Answer 11

Macula ‘on’

Macula ‘off’

Question 12

What are the causes of retinal detachment

Answer 12

Rhegmatogenous
Exudative
Tractional

Question 13

What is rhegmatogenous RD

Answer 13

Retinal tear causes flow of vitreous into sub-retinal space

Question 14

What is exudative RD

Answer 14

Inflammatory conditions cause exudation of fluid from leaky vessels into sub-retinal space

Question 15

What is tractional RD

Answer 15

Fibrovascular membranes growing abnormally in vitreous contract and pull retina away from RPE
e.g. proliferative diabetic retinopathy

Question 16

What are clinical features of RD

Answer 16

Photopsia, Floaters
Loss of vision - gradual, begin as shadow in peripheral field, ‘curtain coming upwards’
Blurred vision - Macula ‘off’

Reduced VA: in macula ‘off’, or in bullous RD in front of macula
Tobacco dust - sign of retinal tear: red cells/RPE cells in vitreous, migrated from retina through tear

Question 17

What is the management of RD

Answer 17

Vitreo-retinal surgery:
Rhegmatogenous: laser, cryotherapy, vitrectomy
Exudative: treat the cause
Tractional: relieve traction

Oil or Gas + patient positioning post-operatively: allows compression of retina while awaiting effects of surgery (1wk to take effect)

Question 18

What is prognosis of RD

Answer 18

Macula on: requires urgent surgery - allows good recovery of vision
Superior RD: requires urgent surgery - gravity pulls retina down to macula, risk of macular detachment
Macula off: poor recovery of vision